Modern heating systems of a private house - choose a heating system option from the available ones. Modern heat supply systems development prospects Components of modern heat supply at home

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The arrangement of numerous communications in a private building is a very laborious task, since this work requires increased attention from the owners, and sometimes completely specific building skills. At the same time, special importance, as a rule, is attached to it, since the comfort of living in the house will depend on its quality.

Today it is not enough just to mount and connect all the elements of the heating circuit, it is also important to ensure that the entire system functions not only stably, but also as economically as possible. The constant increase in electricity tariffs, rising prices on the fuel market and other unpleasant factors oblige consumers to equip modern heating of a private house on the principle of the least energy consumption. About what modern heating systems are found, as well as about the features of their design in terms of their efficiency, further will be discussed.

Traditional heating elements at the present stage

Heating boilers

Among the new products in this category that have appeared on the construction market, the following samples can be noted:

• induction type boilers operating from electrical network. These structures are a pipe consisting of a dielectric with a metal core placed inside. They got their name due to the presence of an induction coil wound over the pipe. It is this part of the boiler that is the source of the appearance of energy currents. As a result, the device heats up and transfers thermal energy to the coolant, which, as a rule, is plain water. Among the advantages of this model is high performance, despite the very small size. In addition, the design of the induction boiler does not have components that are prone to wear, which is also important;
• boiler, called electrode. Its shape is also extremely convenient thanks to small size. Heating of the coolant is achieved by placing two electrodes inside it, as a result of which the water, which is an electrolyte, is heated.

  The peculiarity of this model of the boiler is also that it is completely safe for operation, since in the event of even a minimal leak, the mechanism will immediately stop working due to the principle of its design.

  However, due to the fact that the functioning of such a boiler is directly dependent on electricity, its operation can hardly be called economical, since the cost of electricity will be very significant, despite the assurance of many sellers of this equipment;

• boilers called condensing. These mechanisms are heating elements working on gas, or rather, on the energy obtained from its combustion. This means that all combustion products are condensed on a special heat exchange element designed for this purpose, due to which it is heated.

  Such boilers are notable for the fact that their performance is very high (the efficiency can reach 100% and even more, provided that the total amount of generated thermal energy is taken as an indicator of 100%).

  The principle of operation of such a boiler is based on a process such as pyrolysis. Firewood, which serves as the main fuel, burns in two stages. Initially, combustion takes place in conditions of a small amount of oxygen, as a result of which ash and gas appear, which subsequently burns out in a separate chamber. Thanks to this principle of operation, it becomes possible to control the operation of the boiler and distribute the heat throughout the dwelling as conveniently as possible.

Modern heating batteries

• most optimal choice for arranging a heating system in a private building - batteries made of aluminum. These products have excellent technical specifications, and, no less important, quite affordable cost;
• there are also convectors made of copper-aluminum alloy, which belong to bimetal devices, that is, those for the production of which two metals were used. These devices have the form of a copper pipe equipped with special aluminum fins.

• on the floor surface;
• on the wall, when the device is fixed to its surface using brackets;
• inside the floor (in this case, installing a weak, low-power fan near the battery can help increase the heat output).

Varieties of pipes for heating

1. Pipes made of polypropylene. Their strengthening is achieved by reinforcing aluminum-based foil or, alternatively, fiberglass. Such products are characterized by high strength, they are easy to use and easy to install. The strength of the joints of polypropylene pipes is due to special welding using low temperature technology.
2. Pipes made of such innovative material as cross-linked polyethylene. As a rule, such models are used exclusively for the installation of a modern design, called a "warm floor". These products are characterized by high strength and at the same time quite unexpected flexibility, which makes them possible to fold them.

But the option with stainless steel pipes is still more suitable for a city apartment than for a private house, since their installation in a city will require significantly lower costs than in a private type building.

Innovative materials for heating

Underfloor heating system

In order to significantly reduce heat loss, it is worth considering installing a heat source under the floor surface. In this case, the temperature parameter in the dwelling will even out and will be almost the same both under the ceiling and in the floor area.

To date, three options for underfloor heating have been developed, which include the following:

1. Underfloor heating water based. In this case, it is necessary to lay a solid pipe made of metal-plastic or cross-linked polyethylene into the screed. The maximum possible heating of the coolant in such a system should reach 40 °C.
2. Cable operating from the electrical network. This option is a good alternative to a water system, provided that electricity is the main source of energy for heating. There are also samples in the form of heating mats.
3. Underfloor heating film type. This system has the form of a thin mat equipped with small paths along which current flows. It is very convenient to install such a warm floor, since its installation does not require any serious preparatory measures, and the laying of the electric film can be done on any of the surfaces (tile, linoleum, laminate).

Modern heating with infrared heaters

The second version of the heaters can also be equipped with a coil heated, however, to no more than 90 °C. But usually the design of such a model includes a ceramic panel, behind which is the main heating part in the form of a film.

Obvious savings in this case are provided due to two main factors:

1. The distribution of heat in this case is almost identical to that observed in the underfloor heating system - the heated air is evenly distributed over the entire area of ​​​​the room, leaving no cold areas and preventing heat loss.
2. Due to the physical properties of infrared radiation, the comfortable temperature obtained with the help of such heating can be much lower than usual and be about 16 - 18 ° C, which has a positive effect on the consumption of thermal energy and saves money.

Use of thermal accumulators

So, with the help of a heat accumulator, you can set up the system so that the water in the heating circuit will be heated only at night, when the electricity bill is lower, and already during the day the coolant will be gradually transferred to the radiators.

The principle of operation of solar collectors

Externally, this device is a dark-colored tank, on top of which glass is located. Thanks to the black tint, which attracts heat faster than the light one, the tank heats up, and heat losses are minimal thanks to the convection provided by the glass structure.

Of course, such equipment is relevant only during daylight hours, and at night and in cloudy weather, as it becomes clear, there will be no great benefit from such a convector.

Heat pump - a modern heating device

According to the principle of operation, such a pump is in many ways reminiscent of a standard refrigerator, with the only difference being that its operation is directed in the opposite direction, but there is not cooling, but heating.

Energy saving in heat supply systems

Completed by: students of group T-23

Salazhenkov M.Yu.

Krasnov D.

Introduction

Today, the energy saving policy is a priority direction in the development of energy and heat supply systems. In fact, every state enterprise draws up, approves and implements plans for energy saving and energy efficiency improvement of enterprises, workshops, etc.

The country's heating system is no exception. It is quite large and cumbersome, consumes colossal amounts of energy and at the same time there are no less colossal losses of heat and energy.

Let's consider what the heat supply system is, where the greatest losses occur and what complexes of energy-saving measures can be applied to increase the "efficiency" of this system.

Heating systems

Heat supply - supply of heat to residential, public and industrial buildings (structures) to meet household (heating, ventilation, hot water supply) and technological needs of consumers.

In most cases, heat supply is the creation of a comfortable indoor environment - at home, at work or in public place. Heat supply also includes heating of tap water and water in swimming pools, heating of greenhouses, etc.

Distance over which heat is transported in modern systems district heating reaches several tens of kilometers. The development of heat supply systems is characterized by an increase in the power of the heat source and unit capacities of the installed equipment. Thermal power of modern thermal power plants reaches 2-4 Tkal/h, regional boiler houses 300-500 Gkal/h. In some heat supply systems, several heat sources work together for common heat networks, which increases the reliability, flexibility and efficiency of heat supply.

The water heated in the boiler room can circulate directly to the heating system. Hot water is heated in the heat exchanger of the hot water supply system (DHW) to a lower temperature, about 50-60 ° C. The return water temperature can be an important factor in boiler protection. The heat exchanger not only transfers heat from one circuit to another, but also effectively copes with the pressure difference that exists between the first and second circuits.

The desired floor heating temperature (30°C) can be obtained by adjusting the temperature of the circulating hot water. The temperature difference can also be achieved by using a three-way valve that mixes hot water with return water in the system.

Regulation of heat supply in heat supply systems (daily, seasonal) is carried out both in the heat source and in heat-consuming installations. In water heating systems, the so-called central quality control of heat supply is usually carried out for the main type of heat load - heating or for a combination of two types of load - heating and hot water supply. It consists in changing the temperature of the heat carrier supplied from the heat supply source to the heat network in accordance with the accepted temperature schedule (that is, the dependence of the required water temperature in the network on the outside air temperature). Central qualitative regulation is supplemented by local quantitative regulation in heating points; the latter is most common in hot water applications and is usually carried out automatically. In steam heating systems, local quantitative regulation is mainly carried out; the steam pressure in the heat supply source is maintained constant, the steam flow is regulated by consumers.

1.1 Composition of the heating system

The heat supply system consists of the following functional parts:

1) source of heat energy production (boiler house, thermal power plant, solar collector, devices for the utilization of industrial heat waste, installations for the use of heat from geothermal sources);

2) transporting devices of thermal energy to the premises (heating networks);

3) heat-consuming devices that transfer thermal energy to the consumer (heating radiators, heaters).

1.2 Classification of heating systems

According to the place of heat generation, heat supply systems are divided into:

1) centralized (the source of heat energy production works for the heat supply of a group of buildings and is connected by transport devices with heat consumption devices);

2) local (the consumer and the source of heat supply are located in the same room or in close proximity).

The main advantages of district heating over local heating are a significant reduction in fuel consumption and operating costs (for example, by automating boiler plants and increasing their efficiency); the possibility of using low-grade fuel; reducing the degree of air pollution and improving the sanitary condition of populated areas. In local heating systems, heat sources are furnaces, hot water boilers, water heaters (including solar), etc.

According to the type of heat carrier, heat supply systems are divided into:

1) water (with temperature up to 150 °C);

2) steam (pressure 7-16 atm).

Water serves mainly to cover domestic, and steam - technological loads. The choice of temperature and pressure in heat supply systems is determined by the requirements of consumers and economic considerations. With an increase in the distance of heat transportation, an economically justified increase in the parameters of the coolant increases.

According to the method of connecting the heating system to the heat supply system, the latter are divided into:

1) dependent (the coolant heated in the heat generator and transported through heating networks enters directly into heat-consuming devices);

2) independent (the coolant circulating through the heating networks in the heat exchanger heats the coolant circulating in the heating system). (Fig.1)

In independent systems, consumer installations are hydraulically isolated from the heating network. Such systems are mainly used in large cities - in order to increase the reliability of heat supply, as well as in cases where the pressure regime in the heat network is unacceptable for heat-consuming installations due to their strength or when the static pressure created by the latter is unacceptable for the heat network ( such are, for example, the heating systems of high-rise buildings).

Figure 1 - Schematic diagrams of heat supply systems according to the method of connecting heating systems to them

According to the method of connecting the hot water supply system to the heat supply system:

1) closed;

2) open.

In closed systems, hot water supply is supplied with water from the water supply, heated to the required temperature by water from the heating network in heat exchangers installed in heating points. In open systems, water is supplied directly from the heating network (direct water intake). Water leakage due to leaks in the system, as well as its consumption for water intake, are compensated by additional supply of an appropriate amount of water to the heating network. To prevent corrosion and scale formation on the inner surface of the pipeline, the water supplied to the heating network undergoes water treatment and deaeration. In open systems, the water must also meet the requirements for potable water. The choice of system is determined mainly by the presence of a sufficient amount of water of drinking quality, its corrosive and scale-forming properties. Both types of systems have become widespread in Ukraine.

According to the number of pipelines used to transfer the coolant, heat supply systems are distinguished:

single-pipe;

two-pipe;

multipipe.

Single-pipe systems are used in cases where the coolant is completely used by consumers and is not returned back (for example, in steam systems without condensate return and in open water systems, where all the water coming from the source is disassembled for hot water supply to consumers).

In two-pipe systems, the heat carrier is fully or partially returned to the heat source, where it is heated and replenished.

Multi-pipe systems suit, if necessary, the allocation of certain types of heat load (for example, hot water supply), which simplifies the regulation of heat supply, operation mode and methods of connecting consumers to heating networks. In Russia, two-pipe heat supply systems are predominantly used.

1.3 Types of heat consumers

The heat consumers of the heat supply system are:

1) heat-using sanitary systems of buildings (systems of heating, ventilation, air conditioning, hot water supply);

2) technological installations.

The use of hot water for space heating is quite common. At the same time, a variety of methods for transferring water energy are used to create a comfortable indoor environment. One of the most common is the use of heating radiators.

An alternative to heating radiators is floor heating, when the heating circuits are located under the floor. The floor heating circuit is usually connected to the heating radiator circuit.

Ventilation - a fan coil unit that supplies hot air to a room, usually used in public buildings. Often a combination of heating devices is used, for example, radiators for heating and underfloor heating or radiators for heating and ventilation.

Hot tap water has become part of everyday life and daily needs. Therefore, a hot water installation must be reliable, hygienic and economical.

According to the mode of heat consumption during the year, two groups of consumers are distinguished:

1) seasonal, requiring heat only during the cold season (for example, heating systems);

2) year-round, requiring heat all year round (hot water supply systems).

Depending on the ratio and modes of individual types of heat consumption, three characteristic groups of consumers are distinguished:

1) residential buildings (characterized by seasonal heat consumption for heating and ventilation and year-round - for hot water supply);

2) public buildings (seasonal heat consumption for heating, ventilation and air conditioning);

3) industrial buildings and structures, including agricultural complexes (all types of heat consumption, the quantitative ratio between which is determined by the type of production).

2 District heating

District heating is an environmentally friendly and reliable way to provide heat. District heating systems distribute hot water or, in some cases, steam from a central boiler plant between multiple buildings. There is a very wide range of sources that serve to generate heat, including the burning of oil and natural gas or the use of geothermal waters. The use of heat from low temperature sources, such as geothermal heat, is possible with the use of heat exchangers and heat pumps. Possibility of using unrecovered heat industrial enterprises, surplus heat from waste treatment, industrial processes and sewerage, targeted heating plants or thermal power plants in district heating, allows for the optimal choice of heat source in terms of and energy efficiency. This way you optimize costs and protect the environment.

Hot water from the boiler house is fed to a heat exchanger that separates the production site from the distribution pipelines of the district heating network. The heat is then distributed to the final consumers and fed through the substations to the respective buildings. Each of these substations usually includes one heat exchanger for space heating and hot water.

There are several reasons for installing heat exchangers to separate a heating plant from a district heating network. Where there are significant pressure and temperature differences that can cause serious damage to equipment and property, a heat exchanger can keep sensitive heating and ventilation equipment from entering contaminated or corrosive media. Another important reason for separating the boiler house, distribution network and end users is to clearly define the functions of each component of the system.

In a combined heat and power plant (CHP), heat and electricity are produced simultaneously, with heat being the by-product. Heat is usually used in district heating systems, leading to increased energy efficiency and cost savings. The degree of use of energy obtained from fuel combustion will be 85–90%. The efficiency will be 35–40% higher than in the case of separate production of heat and electricity.

In a thermal power plant, burning fuel heats water, which turns into steam. high pressure and high temperature. The steam drives a turbine connected to a generator that produces electricity. After the turbine, the steam is condensed in a heat exchanger. The heat released during this process is then fed into the district heating pipes and distributed to the final consumers.

For the end consumer, district heating means uninterrupted energy supply. The district heating system is more convenient and efficient than small individual systems home heating. Modern fuel combustion and emission treatment technologies reduce the negative impact on the environment.

In apartment buildings or other buildings heated by district heating, the main requirement is heating, hot water supply, ventilation and underfloor heating for a large number consumers with minimal energy consumption. Using high-quality equipment in the heating system, you can reduce overall costs.

Another very important task of heat exchangers in district heating is to ensure safety. internal system by separating end consumers from the distribution network. This is necessary because of the significant difference in temperature and pressure values. In the event of an accident, the risk of flooding can also be minimized.

In central heating points, a two-stage scheme for connecting heat exchangers is often found (Fig. 2, A). This connection means maximum heat utilization and low return water temperature when using a hot water system. It is especially advantageous when working with combined heat and power plants, where low temperature return water. This type of substation can easily supply heat to up to 500 apartments, and sometimes more.

A) Two-stage connection B) Parallel connection

Figure 2 - Scheme of connecting heat exchangers

Parallel connection of a DHW heat exchanger (Fig. 2, B) is less complicated than a two-stage connection and can be applied to any plant size that does not need a low return water temperature. Such a connection is usually used for small and medium-sized heating points with a load of up to approximately 120 kW. Connection diagram for hot water heaters in accordance with SP 41-101-95.

Most district heating systems place high demands on the installed equipment. The equipment must be reliable and flexible, providing the necessary safety. In some systems, it must also meet very high hygiene standards. Another important factor in most systems is low operating costs.

However, in our country, the district heating system is in a deplorable state:

technical equipment and the level of technological solutions in the construction of heat networks correspond to the state of the 1960s, while the radii of heat supply have sharply increased, and there has been a transition to new standard sizes of pipe diameters;

the quality of metal of heat pipelines, thermal insulation, shut-off and control valves, construction and laying of heat pipelines are significantly inferior to foreign counterparts, which leads to large losses of thermal energy in networks;

poor conditions for thermal and waterproofing of heat pipelines and channels of heat networks contributed to an increase in the damage of underground heat pipelines, which led to serious problems in replacing the equipment of heat networks;

domestic equipment of large CHPPs corresponds to the average foreign level of the 1980s, and at present, steam turbine CHPPs are characterized by a high accident rate, since almost half of the installed capacity of the turbines has exhausted the estimated resource;

there are no purification systems at operating coal-fired CHP plants flue gases from NOx and SOx, and the efficiency of catching particulate matter often does not reach the required values;

The competitiveness of DH at the present stage can only be ensured by the introduction of specially new technical solutions, both in terms of the structure of systems, and in terms of schemes, equipment of energy sources and heating networks.

2.2 Efficiency of district heating systems

One of the most important conditions for the normal operation of the heat supply system is the creation of a hydraulic regime that provides pressure in the heat network sufficient to create network water flows in heat-consuming installations in accordance with a given heat load. The normal operation of heat consumption systems is the essence of providing consumers with thermal energy of the appropriate quality, and for the energy supply organization it consists in maintaining the parameters of the heat supply mode at the level regulated by the Rules for Technical Operation (PTE) of power plants and networks of the Russian Federation, PTE of thermal power plants. The hydraulic regime is determined by the characteristics of the main elements of the heat supply system.

During operation in the existing district heating system due to a change in the nature of the heat load, the connection of new heat consumers, an increase in the roughness of pipelines, adjustments of the design temperature for heating, changes temperature graph As a rule, uneven supply of heat to consumers, overestimation of network water consumption and reduction in pipeline throughput occurs.

In addition to this, as a rule, there are problems in the heating systems. Such as the misregulation of heat consumption modes, the understaffing of elevator units, unauthorized violation by consumers of connection schemes (established by projects, specifications and contracts). These problems of heat consumption systems are manifested, first of all, in the misregulation of the entire system, characterized by increased coolant flow rates. As a result, insufficient (due to increased pressure losses) available pressures of the coolant at the inlets, which in turn leads to the desire of subscribers to provide the necessary drop by draining the network water from the return pipelines to create at least a minimum circulation in the heating appliances (violations of connection schemes and etc.), which leads to an additional increase in flow and, consequently, to additional pressure losses, and to the emergence of new subscribers with reduced pressure drops, etc. There is a "chain reaction" in the direction of a total misalignment of the system.

All this has a negative impact on the entire heat supply system and on the activities of the energy supply organization: the inability to comply with the temperature schedule; increased replenishment of the heat supply system, and when the water treatment capacity is exhausted, forced replenishment with raw water (consequence - internal corrosion, premature failure of pipelines and equipment); forced increase in heat supply to reduce the number of complaints from the population; increase in operating costs in the system of transport and distribution of thermal energy.

It should be pointed out that in the heat supply system there is always an interrelation of steady-state thermal and hydraulic regimes. A change in the flow distribution (including its absolute value) always changes the heat exchange condition, both directly in heating installations and in heat consumption systems. The result of abnormal operation of the heating system is, as a rule, heat reverse network water.

It should be noted that the temperature of the return network water at the source of thermal energy is one of the main operational characteristics designed to analyze the state of the equipment of thermal networks and the modes of operation of the heat supply system, as well as to assess the effectiveness of measures taken by organizations operating thermal networks in order to increase the level operation of the heating system. As a rule, in the case of misalignment of the heat supply system, the actual value of this temperature differs significantly from its normative, calculated value for this heat supply system.

Thus, when the heat supply system is misaligned, the temperature of the network water, as one of the main indicators of the mode of supply and consumption of thermal energy in the heat supply system, turns out to be: in the supply pipeline, almost in all intervals of the heating season, it is characterized by low values; the temperature of the return network water, despite this, is characterized by increased values; the temperature difference in the supply and return pipelines, namely this indicator (along with the specific consumption of network water per connected heat load) characterizes the level of quality of heat energy consumption, is underestimated compared to the required values.

It should be noted one more aspect related to the increase relative to the calculated value of network water consumption for the thermal regime of heat consumption systems (heating, ventilation). For direct analysis, it is advisable to use the dependence that determines, in the event of a deviation of the actual parameters and structural elements of the heat supply system from the calculated ones, the ratio of the actual heat energy consumption in heat consumption systems to its calculated value.

where Q is the consumption of thermal energy in heat consumption systems;

g - consumption of network water;

tp and tо - temperature in the supply and return pipelines.

This dependence (*) is shown in Fig.3. The ordinate shows the ratio of the actual consumption of thermal energy to its calculated value, the abscissa shows the ratio of the actual consumption of network water to its calculated value.

Figure 3 - Graph of the dependence of the consumption of thermal energy by systems

heat consumption from the consumption of network water.

As general trends, it is necessary to point out that, firstly, an increase in network water consumption by n times does not cause an increase in thermal energy consumption corresponding to this number, that is, the heat consumption coefficient lags behind the network water consumption coefficient. Secondly, with a decrease in the consumption of network water, the supply of heat to the local heat consumption system decreases the faster, the lower the actual consumption of network water compared to the calculated one.

Thus, heating and ventilation systems react very poorly to excessive consumption of network water. Thus, an increase in the consumption of network water for these systems by 50% relative to the calculated value causes an increase in heat consumption by only 10%.

The point in Fig. 3 with coordinates (1; 1) displays the calculated, actually achievable mode of operation of the heat supply system after commissioning. Under the actually achievable mode of operation is meant such a mode, which is characterized by the existing position of the structural elements of the heat supply system, heat losses by buildings and structures and determined by the total consumption of network water at the outlets of the heat source, necessary to provide a given heat load with the existing heat supply schedule.

It should also be noted that the increased consumption of network water, due to the limited capacity of heat networks, leads to a decrease in the available pressures at the consumer inlets necessary for the normal operation of heat-consuming equipment. It should be noted that the pressure loss in the heating network is determined by a quadratic dependence on the network water flow:

That is, with an increase in the actual consumption of network water GF by 2 times relative to the calculated value GP, the pressure losses in the heating network increase by 4 times, which can lead to unacceptably small available pressures at the thermal nodes of consumers and, consequently, to insufficient heat supply to these consumers, which can cause unauthorized discharge of network water to create circulation (unauthorized violation by consumers of connection schemes, etc.)

Further development of such a heat supply system along the path of increasing the flow rate of the coolant, firstly, will require the replacement of the head sections of the heat pipelines, the additional installation of network pumping units, an increase in the productivity of water treatment, etc., and secondly, it leads to an even greater increase in additional costs - the cost of compensation for electricity, make-up water, heat losses.

Thus, it seems technically and economically more justified to develop such a system by improving its quality indicators - increasing the temperature of the coolant, pressure drops, increasing the temperature difference (heat removal), which is impossible without a drastic reduction in coolant consumption (circulation and make-up) in heat consumption systems and , respectively, in the entire heating system.

Thus, the main measure that can be proposed to optimize such a heat supply system is the adjustment of the hydraulic and thermal regime of the heat supply system. The technical essence of this measure is to establish the flow distribution in the heat supply system based on the calculated (i.e., corresponding to the connected heat load and the selected temperature schedule) network water consumption for each heat consumption system. This is achieved by installing appropriate throttling devices (automatic regulators, throttle washers, elevator nozzles) at the inputs to the heat consumption systems, the calculation of which is based on the calculated pressure drop at each input, which is calculated based on the hydraulic and thermal calculation of the entire heat supply system.

It should be noted that the creation of a normal mode of operation of such a heat supply system is not limited only to carrying out adjustment measures, it is also necessary to carry out work to optimize the hydraulic mode of the heat supply system.

Regime adjustment covers the main links of the district heating system: a water-heating installation of a heat source, central heating points (if any), a heat network, control and distribution points (if any), individual heating points and local heat consumption systems.

Commissioning begins with an inspection of the district heating system. The collection and analysis of initial data on the actual operating modes of the system of transport and distribution of heat energy, information on the technical condition of heat networks, the degree of equipment of the heat source, heat networks and subscribers with commercial and technological measuring instruments is carried out. The applied modes of heat energy supply are analyzed, possible design and installation defects are identified, information is selected to analyze the characteristics of the system. The analysis of operational (statistical) information (sheets of accounting for coolant parameters, modes of supply and consumption of energy, actual hydraulic and thermal modes of heating networks) is carried out with different values outside air temperature in the base periods, obtained according to the readings of standard measuring instruments, as well as an analysis of reports from specialized organizations.

At the same time, a design scheme for heat networks is being developed. A mathematical model of the heat supply system is being created on the basis of the ZuluThermo calculation complex, developed by Politerm (St. Petersburg), capable of simulating the actual thermal and hydraulic operation of the heat supply system.

It should be pointed out that there is a fairly common approach, which consists in minimizing the financial costs associated with the development of measures to adjust and optimize the heat supply system, namely, the costs are limited to the acquisition of a specialized software package.

The "pitfall" in this approach is the reliability of the original data. The mathematical model of the heat supply system, created on the basis of unreliable initial data on the characteristics of the main elements of the heat supply system, turns out, as a rule, to be inadequate to reality.

2.3 Energy saving in DH systems

AT recent times there are critical remarks about district heating based on district heating - the joint generation of heat and electrical energy. As the main disadvantages, there are large heat losses in pipelines during heat transport, a decrease in the quality of heat supply due to non-compliance with the temperature schedule and the required pressure from consumers. It is proposed to switch to decentralized, autonomous heat supply from automated boiler houses, including those located on the roofs of buildings, justifying this with lower cost and no need to lay heat pipelines. But at the same time, as a rule, it is not taken into account that the connection of the heat load to the boiler room makes it impossible to generate cheap electricity for heat consumption. Therefore, this part of the ungenerated electricity should be replaced by its production by the condensation cycle, the efficiency of which is 2-2.5 times lower than that of the heating cycle. Consequently, the cost of electricity consumed by the building, the heat supply of which is carried out from the boiler house, should be higher than that of the building connected to the heating system of heat supply, and this will cause a sharp increase in operating costs.

S. A. Chistovich at the anniversary conference "75 years of district heating in Russia", held in Moscow in November 1999, suggested that home boiler houses complement district heating, acting as peak heat sources, where the lacking capacity of networks does not allow for high-quality supply consumer heat. At the same time, heat supply is preserved and the quality of heat supply is improved, but this decision reeks of stagnation and hopelessness. It is necessary that the district heating supply fully performs its functions. Indeed, district heating has its own powerful peak boiler houses, and it is obvious that one such boiler house will be more economical than hundreds of small ones, and if the capacity of the networks is insufficient, then it is necessary to shift the networks or cut off this load from the networks so that it does not violate the quality of heat supply to other consumers.

Great success in district heating has been achieved by Denmark, which, despite the low concentration of heat load per 1 m2 of surface area, is ahead of us in terms of district heating coverage per capita. In Denmark, a special state policy is being pursued to prefer the connection to district heating of new heat consumers. In Western Germany, for example in Mannheim, district heating based on district heating is developing rapidly. In the Eastern lands, where, focusing on our country, heat supply was also widely used, despite the rejection of panel housing construction, central heating in residential areas that turned out to be inefficient in a market economy and the Western way of life, the area of ​​centralized heat supply based on heat supply continues to develop as the most environmentally friendly and cost effective.

All of the above indicates that at the new stage we must not lose our leading positions in the field of district heating, and for this it is necessary to modernize the district heating system in order to increase its attractiveness and efficiency.

All the advantages of joint generation of heat and electricity were attributed to electricity, district heating was financed according to the residual principle - sometimes the CHP had already been built, but the heating networks had not yet been brought up. As a result, low-quality heat pipelines with poor insulation and inefficient drainage were created, heat consumers were connected to heat networks without automatic load control, in best case with the use of hydraulic regulators for stabilizing the coolant flow of very poor quality.

This forced the supply of heat from the source according to the method of central quality control (by changing the temperature of the coolant depending on the outside temperature according to a single schedule for all consumers with constant circulation in the networks), which led to a significant overconsumption of heat by consumers due to differences in their operating mode and impossibility joint work multiple heat sources single network for making mutual reservations. The absence or inefficiency of the operation of control devices at the points of connection of consumers to heating networks also caused an overrun of the volume of the coolant. This led to an increase in the return water temperature to such an extent that there was a danger of failure of the station circulating pumps and this forced the reduction of heat supply at the source, violating the temperature schedule even in conditions of sufficient power.

Unlike us, in Denmark, for example, all the benefits of district heating in the first 12 years are given to the side of thermal energy, and then they are divided in half with electrical energy. As a result, Denmark was the first country to produce pre-insulated pipes for ductless installation with a sealed cover layer and an automatic leak detection system, which drastically reduced heat loss during transportation. In Denmark, for the first time, silent, supportless "wet-running" circulation pumps, heat metering devices and effective systems for auto-regulating the heat load were invented, which made it possible to build automated individual heating points (ITP) directly in the buildings of consumers with automatic control of the supply and metering of heat in places of its use.

Total automation of all heat consumers made it possible: to abandon the qualitative method of central regulation at the heat source, which causes undesirable temperature fluctuations in the pipelines of the heating network; reduce the maximum water temperature parameters to 110-1200C; ensure the possibility of operation of several heat sources, including waste incinerators, on a single network with the most efficient use of each.

The temperature of the water in the supply pipeline of heating networks varies depending on the level of the established outdoor temperature in three steps: 120-100-80°C or 100-85-70°C (there is a tendency to an even greater decrease in this temperature). And inside each stage, depending on the change in load or the deviation of the outside temperature, the flow rate of the coolant circulating in the heating networks changes according to the signal of the fixed value of the pressure difference between the supply and return pipelines - if the pressure difference drops below the set value, then the subsequent heat generating and pumping stations are switched on installation. Heat supply companies guarantee each consumer a specified minimum level of pressure drop in the supply networks.

Consumers are connected through heat exchangers, and, in our opinion, an excessive number of connection steps are used, which is apparently caused by the boundaries of property ownership. Thus, the following connection scheme was demonstrated: to the main networks with design parameters of 125 ° C, which are administered by the energy producer, through a heat exchanger, after which the temperature of the water in the supply pipeline drops to 120 ° C, distribution networks are connected, which are in municipal ownership.

The level of maintenance of this temperature is set by an electronic regulator that acts on a valve installed on the return pipeline of the primary circuit. In the secondary circuit, the coolant is circulated by pumps. Connection to these distributing networks of local heating and hot water supply systems of individual buildings is carried out through independent heat exchangers installed in the basements of these buildings with a full range of heat control and metering devices. Moreover, the regulation of the temperature of the water circulating in the local heating system is carried out according to the schedule, depending on the change in the temperature of the outside air. Under design conditions, the maximum water temperature reaches 95°C, recently there has been a tendency to decrease it to 75-70°C, the maximum return water temperature is 70 and 50°C, respectively.

The connection of heating points of individual buildings is carried out according to standard schemes with parallel connection of a hot water storage tank or according to a two-stage scheme using the potential of the heat carrier from the return pipeline after the heating water heater using high-speed hot water heat exchangers, while it is possible to use a hot water pressure storage tank with a pump for tank charging. In the heating circuit, pressurized membrane tanks are used to collect water when it expands from heating; in our case, atmospheric expansion tanks installed at the top of the system are more used.

To stabilize the operation of the control valves at the inlet to the heating point, a hydraulic regulator for the constancy of the pressure difference is usually installed. And in order to bring the heating systems with pump circulation to the optimal operating mode and facilitate the distribution of the coolant along the risers of the system, a "partner valve" in the form of a balance valve, which allows, according to the pressure loss measured on it, to set the correct flow rate of the circulating coolant.

In Denmark, they do not pay much attention to the increase in the calculated flow rate of the heat carrier at the heating point when turning on the heating of water for domestic needs. In Germany, it is forbidden by law to take into account the load on hot water supply when selecting heat power, and when automating heating points, it is accepted that when the hot water heater is turned on and when the storage tank is filled, the pumps that circulate in the heating system are turned off, i.e., the heat supply to the heating.

In our country, great importance is also attached to preventing an increase in the power of the heat source and the estimated flow rate of the heat carrier circulating in the heating network during the hours of the maximum hot water supply. But the solution adopted in Germany for this purpose cannot be applied in our conditions, since we have a much higher load ratio of hot water supply and heating, due to the large absolute consumption of household water and the higher population density.

Therefore, when automating the heat points of consumers, the limitation of the maximum water flow from the heating network is used when the specified value is exceeded, determined based on the average hourly load of the hot water supply. When heating residential areas, this is done by closing the valve of the heat supply regulator for heating during the hours of the maximum water consumption. By setting the heating controller to some overestimation of the maintained heat carrier temperature curve, the underheating in the heating system that occurs when the maximum watershed is passed is compensated during drawdown periods below the average (within the specified water flow from the heating network - coupled regulation).

The water flow sensor, which is a signal for limitation, is a water flow meter included in the heat meter kit installed at the heating network inlet to the central heating substation or ITP. The differential pressure regulator at the inlet cannot serve as a flow limiter, since it provides a given differential pressure in conditions of full opening of the valves of the heating and hot water supply regulators installed in parallel.

In order to increase the efficiency of the joint generation of heat and electricity and equalize the maximum energy consumption in Denmark, heat accumulators, which are installed at the source, are widely used. The lower part of the accumulator is connected to the return pipeline of the heating network, the upper part is connected to the supply pipeline through a movable diffuser. With a reduction in circulation in the distribution heating networks, the tank is charged. With an increase in circulation, the excess coolant flow from the return pipeline enters the tank, and hot water is squeezed out of it. The need for heat accumulators increases in CHP plants with backpressure turbines, in which the ratio of generated electrical and thermal energy is fixed.

If the design temperature of the water circulating in the heating networks is below 100 ° C, then atmospheric-type storage tanks are used; at a higher design temperature, pressure is created in the tanks to ensure that hot water does not boil.

However, the installation of thermostats together with heat flow meters for each heating device leads to an almost double increase in the cost of the heating system, and in a single-pipe scheme, in addition, the required heating surface of the devices increases to 15% and there is a significant residual heat transfer of devices in the closed position of the thermostat, which reduces the efficiency of auto-regulation. Therefore, an alternative to such systems, especially in low-cost municipal construction, are façade automatic heating control systems - for extended buildings and central ones with temperature graph correction based on the deviation of air temperature in the prefabricated exhaust ventilation ducts from apartment kitchens - for point buildings or buildings with a complex configuration.

However, it must be borne in mind that when reconstructing existing residential buildings, it is necessary to enter each apartment with welding to install thermostats. At the same time, when organizing façade autoregulation, it is enough to cut jumpers between façade branches of sectional heating systems in the basement and in the attic, and for 9-story non-attic buildings of mass construction of the 60-70s - only in the basement.

It should be noted that new construction per year does not exceed 1-2% of the existing housing stock. This indicates the importance of the reconstruction of existing buildings in order to reduce the cost of heat for heating. However, it is impossible to automate all buildings at once, and in conditions where several buildings are automated, real savings are not achieved, since the heat carrier saved at automated facilities is redistributed among non-automated ones. The above once again confirms that it is necessary to build the PDC at the existing heat networks at a faster pace, since it is much easier to automate all the buildings that are fed from one PDC than from the CHP, and other already created PDCs will not let an excess amount of coolant into their distribution networks.

All of the above does not exclude the possibility of connecting individual buildings to boiler houses with an appropriate feasibility study with an increase in the tariff for consumed electricity (for example, when laying or re-laying a large number of networks is necessary). But in the conditions of the existing system of district heating from CHP, this should have a local character. The possibility of using heat pumps, transferring part of the load to CCGTs and GTUs is not ruled out, but given the current conjuncture of prices for fuel and energy carriers, this is not always profitable.

Heat supply of residential buildings and microdistricts in our country, as a rule, is carried out through group heating points (CHPs), after which individual buildings are supplied through independent pipelines with hot water for heating and for domestic needs with tap water heated in heat exchangers installed in the CHP. Sometimes up to 8 heat pipelines leave the central heating center (with a 2-zone hot water supply system and a significant ventilation load), and although galvanized hot water pipelines are used, due to the lack of chemical water treatment they are subject to intense corrosion and after 3-5 years of operation on them fistulas appear.

Currently, in connection with the privatization of housing and service enterprises, as well as with the increase in the cost of energy carriers, the transition from group heating points to individual (ITP) located in a heated building is relevant. This allows you to apply a more efficient system of façade automatic heating control for extended buildings or a central one with temperature correction indoor air in point buildings, allows you to abandon the distribution networks of hot water, reducing heat losses during transportation and electricity consumption for pumping domestic hot water. Moreover, it is expedient to do this not only in new construction, but also in the reconstruction of existing buildings. There is such experience in the Eastern lands of Germany, where central heating stations were built in the same way as we did, but now they are left only as pumping water pumping stations (if necessary), and heat exchange equipment, together with circulation pumps, control and accounting units, are transferred to the ITP of buildings . Intra-quarter networks are not laid, hot water pipelines are left in the ground, and heating pipelines, as more durable ones, are used to supply superheated water to buildings.

In order to improve the manageability of heating networks, to which a large number of IHS will be connected, and to ensure the possibility of redundancy in automatic mode, it is necessary to return to the device of control and distribution points (CDP) at the points of connection of distribution networks to the main ones. Each KRP is connected to the main on both sides of the sectional valves and serves consumers with a thermal load of 50-100 MW. Switching electric gate valves at the inlet, pressure regulators, circulating-mixing pumps, a temperature regulator, a safety valve, heat and coolant consumption metering devices, control and telemechanics devices are installed in the KRP.

The automation circuit of the KRP ensures that the pressure is maintained at a constant minimum level in the return line; maintaining a constant predetermined pressure drop in the distribution network; reduction and maintenance of water temperature in the supply pipeline of the distribution network according to a given schedule. As a result, in the backup mode, it is possible to supply a reduced amount of circulating water with an increased temperature through the mains from the CHPP without disturbing the temperature and hydraulic regimes in the distribution networks.

KRP should be located in ground pavilions, they can be blocked with water pumping stations (this will allow in most cases to refuse to install high-pressure, and therefore noisier pumps in buildings), and can serve as the boundary of the balance sheet ownership of the heat-releasing organization and the heat-distributing one (the next boundary between the heat-distributing and the wall of the building will be the heat-using organization). Moreover, the KRP should be under the jurisdiction of the heat-producing organization, since they serve to control and reserve the main networks and provide the ability to operate several heat sources for these networks, taking into account the maintenance of the coolant parameters specified by the heat-distributing organization at the outlet of the KRP.

The correct use of the heat carrier on the part of the heat consumer is ensured by the use of effective control automation systems. Now there are a large number of computer systems that can perform any complexity of control tasks, but technological tasks and circuit solutions for connecting heat consumption systems remain decisive.

Recently, they began to build water heating systems with thermostats, which carry out individual automatic control of the heat transfer of heating devices according to the air temperature in the room where the device is installed. Such systems are widely used abroad, with the addition of mandatory measurement of the amount of heat used by the device as a share of the total heat consumption of the building's heating system.

In our country, in mass construction, such systems began to be used for elevator connection to heating networks. But the elevator is designed in such a way that, with a constant nozzle diameter and the same available pressure, it passes a constant flow rate of the coolant through the nozzle, regardless of the change in the flow rate of water circulating in the heating system. As a result, in 2-pipe heating systems, in which thermostats, when closed, lead to a reduction in the flow rate of the coolant circulating in the system, when connected to an elevator, the water temperature in the supply pipe will increase, and then in the opposite direction, which will lead to an increase in heat transfer from the unregulated part of the system (risers) and to underutilization of the coolant.

In a single-pipe heating system with permanent closing sections, when the thermostats are closed, hot water is discharged into the riser without cooling, which also leads to an increase in the water temperature in the return pipeline and, due to the constant mixing ratio in the elevator, to an increase in the water temperature in the supply pipeline, and therefore to the same consequences as in a 2-pipe system. Therefore, in such systems, it is mandatory to automatically control the temperature of the water in the supply pipeline according to the schedule, depending on the change in the temperature of the outside air. Such regulation is possible by changing the circuit design for connecting the heating system to the heating network: replacing a conventional elevator with an adjustable one, by using pump mixing with a control valve, or by connecting it through a heat exchanger with pump circulation and a control valve on network water in front of the heat exchanger. [

3 DECENTRALIZED HEATING

3.1 Prospects for the development of decentralized heat supply

Previously decisions made about the closure of small boiler houses (under the pretext of their low efficiency, technical and environmental danger) today turned into over-centralization of heat supply, when hot water passes from the CHPP to the consumer, a path of 25-30 km, when the shutdown of the heat source due to non-payments or an emergency leads to freezing cities with millions of people.

Most of the industrialized countries went the other way: they improved the heat generating equipment by increasing the level of its safety and automation, the efficiency of gas burners, sanitary and hygienic, environmental, ergonomic and aesthetic indicators; created a comprehensive energy accounting system for all consumers; brought the regulatory and technical base in line with the requirements of expediency and convenience of the consumer; optimized the level of heat supply centralization; switched to the widespread introduction of alternative sources of thermal energy. The result of this work was real energy saving in all areas of the economy, including housing and communal services.

A gradual increase in the share of decentralized heat supply, maximum proximity of the heat source to the consumer, accounting by the consumer of all types of energy resources will not only create more comfortable conditions for the consumer, but also ensure real savings in gas fuel.

A modern decentralized heat supply system is a complex set of functionally interconnected equipment, including an autonomous heat generating plant and building engineering systems (hot water supply, heating and ventilation systems). The main elements of the apartment heating system, which is a type of decentralized heat supply, in which each apartment in apartment building equipped with an autonomous system for providing heat and hot water, are a heating boiler, heating appliances, air supply and combustion products removal systems. The wiring is carried out using a steel pipe or modern heat-conducting systems - plastic or metal-plastic.

Traditional for our country, the system of centralized heat supply through CHPPs and main heat pipelines is known and has a number of advantages. But in the context of the transition to new economic mechanisms, the well-known economic instability and the weakness of interregional, interdepartmental relations, many of the advantages of the district heating system turn into disadvantages.

The main one is the length of heating mains. The average percentage of wear is estimated at 60-70%. The specific damage rate of heat pipelines has now increased to 200 registered damage per year per 100 km of heat networks. According to an emergency assessment, at least 15% of heating networks require urgent replacement. In addition to this, over the past 10 years, as a result of underfunding, the main fund of the industry has practically not been updated. As a result, heat energy losses during production, transportation and consumption reached 70%, which led to low quality heat supply at high costs.

The organizational structure of interaction between consumers and heat supply companies does not encourage the latter to save energy resources. The system of tariffs and subsidies does not reflect the real costs of heat supply.

In general, the critical situation in which the industry has found itself suggests a large-scale crisis in the heat supply sector in the near future, the resolution of which will require enormous financial investments.

An urgent issue is the reasonable decentralization of heat supply, apartment heating. Decentralization of heat supply (DT) is the most radical, efficient and cheap way to eliminate many shortcomings. Reasonable use of diesel fuel in combination with energy-saving measures in the construction and reconstruction of buildings will provide greater energy savings in Ukraine. In the current difficult conditions, the only way out is the creation and development of a diesel fuel system through the use of autonomous heat sources.

Apartment heat supply is an autonomous supply of heat and hot water to an individual house or a separate apartment in a multi-storey building. The main elements of such autonomous systems are: heat generators - heaters, pipelines for heating and hot water supply, fuel supply, air and smoke exhaust systems.

The objective prerequisites for the introduction of autonomous (decentralized) heat supply systems are:

the absence in some cases of free capacities at centralized sources;

densification of the development of urban areas with housing objects;

in addition, a significant part of the development falls on areas with undeveloped engineering infrastructure;

lower capital investment and the possibility of phased coverage of thermal loads;

the ability to maintain comfortable conditions in the apartment at one's own will, which in turn is more attractive compared to apartments with centralized heat supply, the temperature in which depends on the directive decision on the beginning and end of the heating period;

the appearance on the market of a large number of various modifications of domestic and imported (foreign) heat generators of low power.

Today, modular boiler plants have been developed and are being mass-produced, designed to organize autonomous diesel fuel. The block-modular principle of construction provides the possibility of simple construction of a boiler house of the required power. The absence of the need to lay heating mains and build a boiler house reduces the cost of communications and can significantly increase the pace of new construction. In addition, this makes it possible to use such boiler houses for the prompt provision of heat supply in emergency and emergencies during the heating season.

Block boiler rooms are a fully functionally finished product, equipped with all necessary automation and safety devices. The level of automation ensures the smooth operation of all equipment without the constant presence of an operator.

Automation monitors the object's need for heat depending on weather conditions and independently regulates the operation of all systems to ensure the specified modes. This achieves better compliance with the thermal schedule and additional fuel savings. In the event of emergency situations, gas leaks, the security system automatically stops the gas supply and prevents the possibility of accidents.

Many enterprises, having oriented themselves to today's conditions and having calculated the economic benefits, are moving away from centralized heat supply, from remote and energy-intensive boiler houses.

The advantages of decentralized heat supply are:

no need for land allotments for heating networks and boiler houses;

reduction of heat losses due to the absence of external heating networks, reduction of network water losses, reduction of water treatment costs;

a significant reduction in the cost of repair and maintenance of equipment;

full automation of consumption modes.

If we take into account the lack of autonomous heating from small boiler houses and relatively low chimneys and, in connection with this, a violation of the environment, then a significant reduction in gas consumption associated with the dismantling of the old boiler house also reduces emissions by 7 times!

With all the advantages, decentralized heat supply also has negative aspects. In small boiler houses, including "roof" ones, the height of the chimneys, as a rule, is much lower than in large ones, because of the dispersion conditions deteriorate sharply. In addition, small boiler houses are located, as a rule, near the residential area.

Implementation of programs for decentralization of heat sources makes it possible to halve the need for natural gas and several times reduce the cost of heat supply to end consumers. The principles of energy saving laid down in the current heating system of Ukrainian cities stimulate the emergence of new technologies and approaches that can fully solve this problem, and the economic efficiency of diesel fuel makes this area very attractive for investment.

The use of an apartment heating system for multi-storey residential buildings makes it possible to completely eliminate heat losses in heating networks and during distribution between consumers, and significantly reduce losses at the source. It will allow organizing individual accounting and regulation of heat consumption depending on economic opportunities and physiological needs. Apartment heating will lead to a reduction in one-time capital investments and operating costs, and also saves energy and raw materials for the generation of thermal energy and, as a result, leads to a decrease in the burden on the environment.

The apartment heating system is an economically, energetically, environmentally efficient solution to the issue of heat supply for multi-storey buildings. And yet, it is necessary to conduct a comprehensive analysis of the effectiveness of the use of a particular heat supply system, taking into account many factors.

Thus, the analysis of the components of losses in autonomous heat supply allows:

1) for the existing housing stock, increase the coefficient of energy efficiency of heat supply to 0.67 versus 0.3 for district heating;

2) for new construction, only by increasing the thermal resistance of enclosing structures, increase the coefficient of energy efficiency of heat supply to 0.77 versus 0.45 for centralized heat supply;

3) when using the entire range of energy-saving technologies, increase the coefficient to 0.85 against 0.66 with district heating.

3.2 Energy efficient solutions for diesel fuel

With autonomous heat supply, new technical and technological solutions can be used to completely eliminate or significantly reduce all unproductive losses in the chain of generation, transportation, distribution and consumption of heat, and not just by building a mini-boiler house, but by using new energy-saving and efficient technologies, such how:

1) transition to a fundamentally new system of quantitative regulation of heat generation and supply at the source;

2) effective use of frequency-controlled electric drive on all pumping units;

3) reducing the length of circulating heating networks and reducing their diameter;

4) refusal to build central heating points;

5) transition to a fundamentally new scheme of individual heat points with quantitative and qualitative regulation depending on the current outdoor temperature using multi-speed mixing pumps and three-way regulator valves;

6) installation of a "floating" hydraulic mode of the heating network and a complete rejection of hydraulic balancing of consumers connected to the network;

7) installation of regulating thermostats on apartment heating appliances;

8) apartment-by-apartment wiring of heating systems with the installation of individual heat consumption meters;

9) automatic maintenance of constant pressure on hot water supply devices for consumers.

The implementation of these technologies allows, first of all, to minimize all losses and creates conditions for the coincidence of the modes of the amount of generated and consumed heat in time.

3.3 Benefits of decentralized heating

If we trace the entire chain: source-transport-distribution-consumer, we can note the following:

1 Heat source - significantly reduced heat dissipation land plot, the cost of the construction part is reduced (no foundations are required for the equipment). The installed power of the source can be chosen almost equal to the consumed one, while it is possible to ignore the load of hot water supply, since during the maximum hours it is compensated by the storage capacity of the consumer's building. Today it is a reserve. Simplifies and reduces the cost of the control scheme. Heat losses are excluded due to the mismatch between the modes of production and consumption, the correspondence of which is established automatically. In practice, only the losses associated with the efficiency of the boiler remain. Thus, at the source it is possible to reduce losses by more than 3 times.

2 Heating networks - the length is reduced, the diameters are reduced, the network becomes more maintainable. A constant temperature regime increases the corrosion resistance of the pipe material. The amount of circulating water decreases, its losses with leaks. There is no need to build a complex water treatment scheme. There is no need to maintain a guaranteed differential pressure before entering the consumer, and in this regard, it is not necessary to take measures for the hydraulic balancing of the heating network, since these parameters are set automatically. Experts imagine what a difficult problem it is - to annually carry out hydraulic calculations and work on hydraulic balancing of an extensive heating network. Thus, losses in heat networks are reduced by almost an order of magnitude, and in the case of a roof-top boiler house for one consumer, these losses do not exist at all.

3 Distribution systems of TsTP and ITP. Required

Modern heating systems are based on various methods heating, which allows you to choose the most suitable option for your country house. Technologies developed over the years will provide not only efficient space heating, but also independent temperature control in each room, fuel economy, automatic and remote control.

Used today in country houses heating and heat supply can be conditionally divided into two groups - classical and innovative. Each group is wide enough, so modern home heating allows you to choose the most effective option for you.

Classic heating systems

Boiler heating with a liquid heat carrier belongs to the classical one. Taking heat from the boiler, the coolant heats the radiators, which in turn release heat into the room by air convection. The boiler can use gas, electricity, diesel fuel or wood as fuel.

Some types of classical heating are getting more advanced options, turning into modern heating systems. For example, electric heating can be direct - the energy is immediately converted into heat without the use of a boiler, coolant, a complex system of pipes and radiators. Direct electric infrared heating is devoid of the disadvantage inherent in standard convection. Infra-red rays heat physical bodies, not air. The heated air does not accumulate under the ceiling, the room is heated more quickly and evenly. A direct electric heating system requires the least installation and maintenance costs.

Air heating also does not use an intermediate heat carrier. The air heated by the boiler through the air ducts immediately enters the heated room. Simultaneously with heating, this method allows for air conditioning and ventilation of rooms.

Modern heating systems sometimes turn to the past, not without success. For example, engineers were able to improve obsolete solid fuel heating. In a pyrolysis solid fuel boiler, the combustion of firewood occurs according to a complex scheme with the formation of combustible pyrolysis gas. Gas is afterburned in a separate furnace, as a result, the overall efficiency of the boiler increases.

The most important indicator of the effectiveness of modern autonomous heating is the possibility of flexible automatic, program and remote control. The most simple and effective automation lends itself to gas, electric and air heating. Thanks to flexible control, modern heating systems can be easily integrated into a "smart home", increasing the overall comfort of living.

Innovative heating systems

Modern heating systems are inseparable from the search for new solutions. The innovative category includes all energy-independent heating technologies using renewable energy sources - solar radiation, wind and wave energy, a heat pump, etc. It is still too expensive, technologically difficult and not always effective to make modern heating systems for a summer house or a cottage non-volatile today. But every year technologies are improved, bringing closer the possibility of organizing completely independent heating. Currently, non-volatile technologies are used to organize additional, backup and emergency heating.

Whichever heating system of a country house you choose, you first need to minimize the heat loss of the building. To do this, when designing and building a house, special architectural solutions, energy-saving materials and technologies are used. Heat accumulators are actively used, which allow storing heat at night at reduced electricity tariffs.

Modern heating of a country house is characterized not only by efficiency, economy, but also by high performance. A professionally designed and installed heating system has a long service life, allows you to quickly maintain, repair and upgrade equipment.

Ministry of Education and Science

GOU VPO "Brotherly State University»

Faculty of Energy and Automation

Department of Industrial Heat Power Engineering

Discipline abstract

"Heat and ventilation"

Modern heating systems

Development prospects

Performed:

St group TGV-08

ON THE. Snegirev

Supervisor:

Professor, Ph.D., Department of PTE

S.A. Semenov

Bratsk 2010

Introduction

1. Types of central heating systems and the principles of their operation

4.2 Gas heating

4.3 Air heating

4.4 Electric heating

4.5 Piping

4.6 Boiler equipment

5. Prospects for the development of heat supply in Russia

Conclusion

List of used literature

Introduction

Living in temperate latitudes, where the main part of the year is cold, it is necessary to provide heat supply to buildings: residential buildings, offices and other premises. Heat supply provides comfortable living if it is an apartment or a house, productive work if it is an office or a warehouse.

First, let's figure out what is meant by the term "Heat supply". Heat supply is the supply of heating systems of a building with hot water or steam. The usual source of heat supply is CHP and boiler houses. There are two types of heat supply for buildings: centralized and local. With a centralized supply, certain areas (industrial or residential) are supplied. For the efficient operation of a centralized heating network, it is built by dividing it into levels, the work of each element is to perform one task. With each level, the task of the element decreases. Local heat supply - the supply of heat to one or more houses. District heating networks have a number of advantages: reduced fuel consumption and cost reduction, use of low-grade fuel, improved sanitation of residential areas. The district heating system includes a source of thermal energy (CHP), a heat network and heat-consuming installations. CHP plants produce heat and energy in combination. Sources of local heat supply are stoves, boilers, water heaters.

Heating systems are characterized by different water temperatures and pressures. It depends on customer requirements and economic considerations. With an increase in the distance over which it is necessary to "transfer" heat, increase economic costs. At present, the heat transfer distance is measured in tens of kilometers. Heat supply systems are divided according to the volume of heat loads. Heating systems are seasonal, and hot water systems are permanent.

1. Types of central heating systems and the principles of their operation

District heating consists of three interrelated and sequential stages: preparation, transportation and use of the heat carrier. In accordance with these stages, each system consists of three main links: a heat source (for example, a combined heat and power plant or a boiler house), heat networks (heat pipelines) and heat consumers.

In decentralized heat supply systems, each consumer has its own heat source.

Heat carriers in central heating systems can be water, steam and air; the corresponding systems are called systems of water, steam or air heating. Each of them has its own advantages and disadvantages. heating central heating

The advantages of a steam heating system are its significantly lower cost and metal consumption compared to other systems: when condensing 1 kg of steam, approximately 535 kcal is released, which is 15-20 times more than the amount of heat released when 1 kg of water cools in heating devices, and therefore steam pipelines have a much smaller diameter than the pipelines of a water heating system. In steam heating systems, the surface of the heating devices is also smaller. In rooms where people stay periodically (industrial and public buildings), the steam heating system will make it possible to produce heating intermittently and there is no danger of freezing of the coolant with subsequent rupture of pipelines.

The disadvantages of the steam heating system are its low hygienic qualities: dust in the air burns on heaters heated to 100 ° C or more; it is impossible to regulate the heat transfer of these devices and for most of the heating period the system must work intermittently; the presence of the latter leads to significant fluctuations in air temperature in heated rooms. Therefore, steam heating systems are arranged only in those buildings where people stay periodically - in baths, laundries, shower pavilions, train stations and clubs.

Air heating systems consume little metal, and they can ventilate the room at the same time as heating the room. However, the cost of an air heating system for residential buildings is higher than other systems.

Water heating systems have a high cost and metal consumption compared to steam heating, but they have high sanitary and hygienic qualities that ensure their wide distribution. They are arranged in all residential buildings with a height of more than two floors, in public and most industrial buildings. Centralized regulation of heat transfer of devices in this system is achieved by changing the temperature of the water entering them.

Water heating systems are distinguished by the method of water movement and design solutions.

According to the method of moving water, systems with natural and mechanical (pumping) motivation are distinguished. Water heating systems with natural impulse. The schematic diagram of such a system consists of a boiler (heat generator), a supply pipeline, heating devices, a return pipeline and an expansion vessel. The water heated in the boiler enters the heating devices, gives them part of its heat to compensate for heat losses through the external fences of the heated building, then returns to the boiler and then the water circulation is repeated. Its movement occurs under the influence of a natural impulse that occurs in the system when the water is heated in the boiler.

The circulation pressure created during the operation of the system is spent on overcoming the resistance to the movement of water through the pipes (from the friction of water against the walls of the pipes) and on local resistances (in bends, taps, valves, heaters, boilers, tees, crosses, etc.) .

The value of these resistances is the greater, the higher the speed of water movement in the pipes (if the speed doubles, then the resistance quadruples, i.e., in a quadratic dependence). In systems with natural impulse in buildings with a small number of storeys, the magnitude of the effective pressure is small, and therefore, high speeds of water movement in pipes cannot be allowed in them; therefore, pipe diameters must be large. The system may not be economically viable. Therefore, the use of systems with natural circulation is allowed only for small buildings. The range of such systems should not exceed 30 m, and the value of k should not be less than 3 m.

When the water in the system is heated, its volume increases. To accommodate this additional volume of water in heating systems, an expansion vessel 3 is provided; in systems with upper wiring and natural impulse, it simultaneously serves to remove air from them, which is released from the water when it is heated in boilers.

Water heating systems with pump impulsion. The heating system is always filled with water and the task of the pumps is to create the pressure necessary only to overcome the resistance to the movement of water. In such systems, natural and pumping impulses operate simultaneously; total pressure for two-pipe systems with top wiring, kgf/m2 (Pa)

For economic reasons, it is usually taken in the amount of 5-10 kgf / m2 per 1 m (49-98 Pa / m).

The advantages of systems with pumping induction are the reduction in the cost of pipelines (their diameter is smaller than in systems with natural induction) and the ability to supply heat to a number of buildings from one boiler house.

The devices of the described system, located on different floors of the building, operate in different conditions. The pressure p2, which circulates water through the device on the second floor, is approximately twice as high as the pressure p1 for the device on the lower floor. At the same time, the total resistance of the pipeline ring passing through the boiler and the device on the second floor is approximately equal to the resistance of the ring passing through the boiler and the device on the first floor. Therefore, the first ring will work with excess pressure, more water will enter the device on the second floor than it is necessary according to the calculation, and accordingly the amount of water passing through the device on the first floor will decrease.

As a result, overheating will occur in the room of the second floor heated by this device, and underheating will occur in the room of the first floor. To eliminate this phenomenon, special methods for calculating heating systems are used, and they also use double-adjustment taps installed on the hot supply to the appliances. If you close these taps at the appliances on the second floor, you can completely extinguish the excess pressure and thereby adjust the water flow for all appliances located on the same riser. However, the uneven distribution of water in the system is also possible for individual risers. This is explained by the fact that the length of the rings and, consequently, their total resistance in such a system for all risers are not the same: the ring passing through the riser (closest to the main riser) has the least resistance; the greatest resistance has the longest ring passing through the riser.

It is possible to distribute water to separate risers by appropriately adjusting the plug (pass-through) taps installed on each riser. For water circulation, two pumps are installed - one working, the second - spare. Near the pumps, they usually make a closed, bypass line with a valve. In the event of a power outage and the pump stops, the valve opens and the heating system operates with natural circulation.

In a pump-driven system, the expansion tank is connected to the system before the pumps, and therefore the accumulated air cannot be expelled through it. To remove air in previously installed systems, the ends of the supply risers were extended with air pipes on which valves were installed (to turn off the riser for repairs). The air line at the point of connection to the air collector is made in the form of a loop that prevents the circulation of water through the air line. Currently, instead of such a solution, air valves are used, screwed into the top plugs of radiators installed on the top floor of the building.

Heating systems with lower wiring are more convenient in operation than systems with upper wiring. So much heat is not lost through the supply line and water leakage from it can be detected and eliminated in a timely manner. The higher the heater is placed in systems with bottom wiring, the greater the pressure available in the annulus. The longer the ring, the greater its total resistance; therefore, in a system with a lower wiring, the overpressures of the devices of the upper floors are much less than in systems with an upper wiring, and, therefore, their adjustment is easier. In systems with lower wiring, the magnitude of the natural impulsion decreases due to the fact that, due to cooling in the supply risers, the ode begins to slow down its movement from top to bottom, so the total pressure acting in such systems

Currently, single-pipe systems are widely used, in which radiators are connected to one riser with both connections; such systems are easier to install and provide more uniform heating of all heating devices. The most common single-pipe system with bottom wiring and vertical risers.

The riser of such a system consists of lifting and lowering parts. Three-way valves can pass the calculated amount or part of the water into the devices in the latter case, the rest of its amount passes, bypassing the device, through the closing sections. The connection of the lifting and lowering parts of the riser is made by a connecting pipe laid under the windows of the upper floor. Air cocks are installed in the upper plugs of the devices located on the upper floor, through which the mechanic removes air from the system during the start-up of the system or when it is abundantly replenished with water. In single-pipe systems, the water passes through all the appliances in sequence, and therefore they must be carefully adjusted. If necessary, the heat transfer of individual devices is adjusted using three-way valves, and the water flow through individual risers - through passage (plug) valves or by installing throttling washers in them. If an excessively large amount of water is supplied to the riser, then the heaters of the riser, which are the first in the direction of water movement, will give off more heat than is necessary according to the calculation.

As you know, the circulation of water in the system, in addition to the pressure created by the pump and natural impulse, is also obtained from the additional pressure Ap, resulting from the cooling of water when moving through the pipelines of the system. The presence of this pressure made it possible to create apartment water heating systems, the boiler of which is not buried, but is usually installed on the kitchen floor. In such cases, the distance, therefore, the system works only due to the additional pressure resulting from the cooling of the water in the pipelines. The calculation of such systems differs from the calculations of heating systems in a building.

Apartment water heating systems are currently widely used instead of stove heating in one- and two-story buildings in gasified cities: in such cases, instead of boilers, automatic gas water heaters (LGW) are installed that provide not only heating, but also hot water supply.

2. Comparison of modern heat supply systems of a thermal hydrodynamic pump type TC1 and a classic heat pump

After the installation of hydrodynamic heat pumps, the boiler room will look more like a pumping station than a boiler room. Eliminates the need for a chimney. There will be no soot and dirt, the need for maintenance personnel will be significantly reduced, the automation and control system will completely take over the processes of managing heat production. Your boiler room will become more economical and high-tech.

Schematic diagrams:

Unlike a heat pump, which can produce a heat carrier with a maximum temperature of up to +65 °C, a hydrodynamic heat pump can heat the heat carrier up to +95 °C, which means that it can be easily integrated into an existing building heat supply system.

In terms of capital costs for the heat supply system, a hydrodynamic heat pump is several times cheaper than a heat pump, because does not require a low-potential heat circuit. Heat pumps and thermal hydrodynamic pumps, similar in name, but differ in the principle of converting electrical energy into heat.

Like a classic heat pump, a hydrodynamic heat pump has a number of advantages:

Profitability (a hydrodynamic heat pump is 1.5-2 times more economical than electric boilers, 5-10 times more economical than diesel boilers).

· Absolute environmental friendliness (the possibility of using a hydrodynamic heat pump in places with limited MPE standards).

· Complete fire and explosion safety.

· Does not demand water treatment. During operation, as a result of the processes taking place in the heat generator of a hydrodynamic heat pump, degassing of the coolant occurs, which has a beneficial effect on the equipment and devices of the heat supply system.

· Fast installation. In the presence of electrical power supplied, the installation of an individual heat point using a hydrodynamic heat pump can be completed in 36-48 hours.

· Payback period from 6 to 18 months, due to the possibility of installation in an existing heating system.

Time to overhaul 10-12 years old. The high reliability of the hydrodynamic heat pump is inherent in its design and confirmed by many years of trouble-free operation of hydrodynamic heat pumps in Russia and abroad.

3. Autonomous heating systems

Autonomous heat supply systems are designed for heating and hot water supply of single-family and detached residential buildings. An autonomous heating and hot water supply system includes: a source of heat supply (boiler) and a network of pipelines with heating appliances and water fittings.

The advantages of autonomous heating systems are as follows:

Lack of expensive external heating networks;

Possibility of quick implementation of installation and commissioning of heating and hot water supply systems;

low initial costs;

simplification of the solution of all issues related to construction, as they are concentrated in the hands of the owner;

· reduction of fuel consumption due to local regulation of heat supply and absence of losses in heat networks.

Such heating systems, according to the principle of accepted schemes, are divided into schemes with natural circulation of the coolant and schemes with artificial circulation of the coolant. In turn, schemes with natural and artificial circulation of the coolant can be divided into one- and two-pipe. According to the principle of coolant movement, schemes can be dead-end, associated and mixed.

For systems with natural induction of the coolant, schemes with upper wiring are recommended, with one or two (depending on the load and design features house) main risers, with an expansion tank installed on the main riser.

The boiler for one-pipe systems with natural circulation can be flush with the lower heaters, but it is better if it is buried, at least to the level of a concrete slab, in a pit or installed in the basement.

The boiler for two-pipe heating systems with natural circulation must be buried in relation to the lower heating device. The depth of penetration is specified by calculation, but not less than 1.5-2 m. Systems with artificial (pumping) induction of the coolant have a wider range of applications. You can design circuits with top, bottom and horizontal wiring of the coolant.

Heating systems are:

water;

air;

electric, including those with a heating cable laid in the floor of heated rooms, and accumulator thermal furnaces (designed with the permission of the energy supply organization).

Water heating systems are designed vertically with heaters installed under window openings and with heating pipelines embedded in the floor structure. In the presence of heated surfaces, up to 30% of the heating load should be provided by heating devices installed under window openings.

Apartment air heating systems combined with ventilation should allow operation in full circulation mode (no people) only on external ventilation (intensive domestic processes) or on a mixture of external and internal ventilation in any desired ratio.

supply air goes through the following processing:

· taken from outside (in the amount of sanitary standard per person 30 m3/h) mixed with recirculated air;

· it is cleared in filters;

heated in heaters;

It is supplied to the serviced premises through a network of air ducts made of metal or embedded in building structures.

Depending on the external conditions, the system must ensure the operation of the unit in 3 modes:

in the outdoor air

Full recirculation

on a mixture of external air recirculation.

4. Modern heating and hot water systems in Russia

Heaters are an element of the heating system, designed to transfer heat from the coolant to the air to the enclosing structures of the serviced premises.

A number of requirements are usually put forward for heating appliances, on the basis of which one can judge the degree of their perfection and make comparisons.

· Sanitary and hygienic. Heaters, if possible, should have a lower case temperature, have the smallest horizontal surface area to reduce dust deposits, allow dust to be freely removed from the case and the enclosing surfaces of the room around them.

· Economic. Heating appliances should have the lowest reduced costs for their manufacture, installation, operation, and also have the lowest metal consumption.

· Architectural and construction. The appearance of the heater must correspond to the interior of the room, and the volume occupied by them must be the smallest, i.e. their volume per unit of heat flow should be the smallest.

· Production and installation. Maximum mechanization of work in the production and installation of heating devices should be ensured. Heating appliances. Heating appliances must have sufficient mechanical strength.

· Operational. Heating devices must ensure the controllability of their heat transfer and provide heat resistance and water tightness at the maximum allowable hydrostatic pressure inside the device under operating conditions.

· Thermotechnical. Heating appliances should provide the highest density of specific heat flux per unit area (W/m).

4.1 Water heating systems

The most common heating system in Russia is water. In this case, the heat is transferred to the premises with hot water contained in the heating devices. The most common way is water heating with natural water circulation. The principle is simple: water moves due to differences in temperature and density. Lighter hot water rises from the heating boiler upwards. Gradually cooling down in the pipeline and heating appliances, it becomes heavier and tends down, back to the boiler. The main advantage of such a system is independence from the power supply and a fairly simple installation. Many Russian craftsmen cope with its installation on their own. In addition, a small circulation pressure makes it safe. But for the system to work, pipes of increased diameter are required. At the same time, reduced heat transfer, limited range and a large amount of time required to start, make it imperfect and suitable only for small houses.

More modern and reliable heating schemes with forced circulation. Here, the water is driven by the circulation pump. It is installed on the pipeline supplying water to the heat generator and sets the flow rate.

Quick start-up of the system and, as a result, quick heating of the premises is the advantage of the pumping system. The disadvantages include that when the power is turned off, it does not work. And this can lead to freezing and depressurization of the system. The heart of the water heating system is the source of heat supply, the heat generator. It is he who creates the energy that provides heat. Such a heart - boilers on different types of fuel. The most popular gas boilers. Another option is a diesel fuel boiler. Electric boilers compare favorably with the absence of an open flame and combustion products. Solid fuel boilers not convenient to use due to the need for frequent heating. To do this, it is necessary to have tens of cubic meters of fuel and space for its storage. And add here the labor costs for loading and harvesting! In addition, the heat transfer mode of a solid fuel boiler is cyclical, and the air temperature in heated rooms fluctuates markedly during the day. A place to store fuel supplies is also necessary for oil-fired boilers.

Aluminum, bimetal and steel radiators

Before choosing any heating device, it is necessary to pay attention to the indicators that the device must meet: high heat transfer, low weight, modern design, small capacity, light weight. The most important characteristic of a heater is heat transfer, that is, the amount of heat that should be in 1 hour per 1 square meter of heating surface. The best device is considered to be the one with the highest this indicator. Heat transfer depends on many factors: the heat transfer medium, the design of the heating device, the method of installation, the color of the paint, the speed of water movement, the speed of washing the device with air. All devices of the water heating system are divided by design into panel, sectional, convectors and columnar aluminum or steel radiators.

Panel heating appliances

Manufactured from cold rolled high quality steel. They consist of one, two or three flat panels, inside of which there is a coolant, they also have ribbed surfaces that heat up from the panels. Heating of the room occurs faster than when using sectional radiators. The above panel water heating radiators are available with side or bottom connection. Side connection is used when replacing an old radiator with side connection or if the slightly unaesthetic appearance of the radiator does not interfere with the interior of the room.

Sectional water heating devices

Made from steel, cast iron or aluminium. They use the convective method of heating the room, that is, they give off heat due to the circulation of air through them. The air passes through the convector from top to bottom and is heated by a large number of warm surfaces.

Convectors

Provide circulation of air in the room when warm air rises, and the cold air, on the contrary, falls down and, passing through the convector, heats up again.

Steel water heating radiator can be both sectional and panel type. Steel is most often exposed to corrosion and therefore these radiators are most suitable for enclosed spaces. Two types of radiators are produced: with horizontal channels and with vertical channels.

Aluminum radiators

Aluminum radiators for water heating are lightweight and have good heat dissipation, aesthetic, but expensive. Often do not withstand high pressure in the system. Their advantage is that they heat the room much faster than cast-iron radiators do.

Bimetal radiators

Bimetallic water heating radiators consist of an aluminum body and steel pipes through which the coolant moves. Their main advantage over other radiators is durability. Their operating pressure reaches up to 40 atm, while aluminum water heating radiators operate at a pressure of 16 atm. Unfortunately, on this moment on the European market, it is very rare to find these bimetallic water heating radiators on sale.

Cast iron column type radiators are the most common type of radiators. They are durable and practical to use. Cast iron radiators are produced in two-column sections. These heaters can be operated at the highest working pressure. Their disadvantage is a lot of weight and inconsistency with the design of the room. The above radiators are used in systems with poor preparation of the coolant. They are quite inexpensive in price.

4.2 Gas heating

The next type of heating for a country house in terms of frequency of use in Russia is gas. In this case, heaters adapted for gas combustion are installed directly in heated rooms.

Gas furnaces are economical and have high thermal performance. A distinctive feature of such furnaces is the uniformity of heating of the outer surface. As additional sources of heat, gas fireplaces are used, which also give special comfort to the interior.

The advantage of gas heating lies, first of all, in the relatively low cost of natural gas. Its use allows you to automate the process of fuel combustion, significantly increases the efficiency of heating equipment, and reduces operating costs. But it is explosive and unacceptable for self-manufacturing and installation.

4.3 Air heating

Air heating systems are distinguished depending on the method of creating air circulation: gravity and fan. Gravity air system heating is based on the difference in air density at different temperatures. During the warm-up process, natural air circulation in the system occurs. The fan system uses an electric fan that increases the air pressure and distributes it through the air ducts and rooms (forced mechanical circulation).

The air is heated in heaters heated from the inside by water, steam, electricity or hot gases. The heater is located either in a separate fan chamber ( central system heating), or directly in the room that is heated (local system).

The absence of a freezing coolant makes this type of heating successful for houses with intermittent use. Air heating will quickly warm up the house, and automatic regulators will maintain the temperature you set. The disadvantages of such heating can only be attributed to the danger of the spread of harmful substances by moving air.

4.4 Electric heating

Systems of direct stationary electric heating are very reliable, environmentally friendly and safe. Electricity heated up to 70% low-rise buildings in the countries of Scandinavia and Finland. Electric heating equipment can be divided into 4 groups: - wall-mounted electric convectors; - ceiling heaters; - cable and film systems for floor and ceiling heating; - control thermostats and programmable devices.

Thanks to this variety, it is easy to choose the right option for each particular room. Equipment and operating costs for electrical systems are very low. Systems can automatically turn on and off to maintain the temperature at a given level. Let's say lower it to a minimum for the duration of your absence. This feature significantly saves energy costs. Rising prices for different kinds fuels make electric heating very attractive for owners of private houses. The disadvantage of electric heating systems is that you will have to install additional equipment to provide the house with hot water. In addition, we still have long blackouts, and the owners of such a system should consider an additional source of heating - just in case.

4.5 Piping

Pipelines for supplying coolant to heating appliances can be made of steel water and gas pipes, copper pipes and polymer materials ( metal-plastic pipes, polypropylene pipes and cross-linked polypropylene pipes). Lines made of steel pipes are not suitable for concealed connections to radiators. All other pipes can be "hidden" under finishing materials subject to certain system installation technologies. It should also be noted that it is not allowed to install a heating system from copper pipes if aluminum sectional radiators are selected as heating devices.

4.6 Boiler equipment

As a rule, heating of urban dwellings is provided from centralized boiler houses and city heating networks, while heating country houses is mainly carried out from own (autonomous) heat sources and only occasionally from a boiler house operating for a group of buildings.

The market for boiler equipment in Russia is quite saturated. Almost all leading Western companies producing boiler equipment have their own representative offices here. Although Russian boilers are widely represented on the market, they still cannot compete with imported samples in terms of consumer qualities. At the same time, almost all Western manufacturers develop and supply boilers to the Russian market, adapted to our conditions:

multi-fuel boilers;

· gas boilers operating without electricity.

Multi-fuel boilers

Almost all companies produce boilers operating on liquid fuel and gas, and some companies add the option solid fuel. It should be noted that multi-fuel boilers, due to the design of the burner, are quite noisy.

gas boilers working without electricity

Now the majority of boilers are designed to work in heating systems with forced circulation of the coolant, and, in the typical case of a power outage in Russia, the boiler simply stops and does not work until there is electricity.

Boiler control systems

The control system for boiler equipment, depending on the purpose of the boiler room (only heating of one building, heating and hot water supply, the presence of underfloor heating circuits, heating and hot water supply of several buildings), can vary from the simplest, made on thermostatic controllers, to complex with microprocessor control.

5. Prospects for the development of heat supply in Russia

The main factors determining the prospects for the development of heat supply in Russia include:

1. The course towards the restructuring of the unified energy system with the formation of a 3-level system of enterprises: heat producers, heat networks and energy sellers. The restructuring will be accompanied by a redistribution of ownership in the energy complex in favor of private entrepreneurship. It is expected to attract large investments, including from abroad. In this case, the restructuring will affect the "large" energy sector.

2. Housing and communal reform associated with the reduction and removal of subsidies to the population in payment utilities, including thermal energy.

3. Stable economic growth in the construction industry.

4. Integration into the country's economy of advanced heat and power technologies of Western countries.

5. Revision of the regulatory framework for thermal power engineering, taking into account the interests of large investors.

6. Approximation of domestic prices for fuel and energy resources to world prices. Formation of a "deficit" of fuel resources of export potential in the domestic market, primarily natural gas and oil. Increasing the share of coal and peat in the country's fuel balance.

7. Formation of a balance of municipal and market mechanisms for the organization and management of regional heat supply.

8. Formation of modern accounting and billing systems in the market for the production, supply and consumption of thermal energy.

Conclusion

Russia belongs to the countries with a high level of heat supply centralization. The energy, environmental and technical advantage of district heating over autonomous in the conditions of a monopoly of state ownership was considered a priori. Autonomous and individual heat supply of individual houses was taken out of the scope of energy and developed according to the residual principle.

In the district heating system, CHPPs are widely used - enterprises for the combined generation of electricity and heat. Technologically, CHPPs are focused on the priority of power supply, the heat produced by the process is in demand to a greater extent in the cold season, and discharged into the environment - in the warm season. It is far from always possible to harmonize the modes of production of heat and electric energy with the modes of their consumption. Nevertheless, the high level of large-scale power generation predetermined “technological independence” and even a certain export potential of the country, which cannot be said about small-scale thermal power generation. Low prices for fuel resources, economically unjustified price of thermal energy did not contribute to the development of "small" boiler building technologies.

Heat supply is an important industry in our life. It brings warmth to our home, provides coziness and comfort, as well as hot water supply, which is necessary every day in the modern world.

Modern heat supply systems significantly save resources, are more convenient to use, meet sanitary and hygienic requirements, are smaller in size and look more aesthetically pleasing.

Bibliography

1. http://www.rosteplo.ru

2. http://dom.ustanovi.ru

3. http://www.boatanchors.ru

4. http://whttp://www.ecoteplo.ru

Ministry of Education of the Russian Federation

Federal State Budgetary Educational Institution of Higher Professional Education "Magnitogorsk State Technical University

them. G.I. Nosov"

(FGBOU VPO "MGTU")

Department of Thermal Power and Energy Systems

abstract

in the discipline "Introduction to the direction"

on the topic: "Centralized and decentralized heat supply"

Completed by: student Sultanov Ruslan Salikhovich

Group: ZEATB-13 "Heat power engineering and heat engineering"

Code: 140100

Checked by: Agapitov Evgeny Borisovich, Doctor of Technical Sciences.

Magnitogorsk 2015

1.Introduction 3

2. District heating 4

3.Decentralized heat supply 4

4. Types of heating systems and principles of their operation 4

5.Modern systems of heating and hot water supply in Russia 10

6. Prospects for the development of heat supply in Russia 15

7. Conclusion 21

1. Introduction

Living in temperate latitudes, where the main part of the year is cold, it is necessary to provide heat supply to buildings: residential buildings, offices and other premises. Heat supply provides comfortable living if it is an apartment or a house, productive work if it is an office or a warehouse.

First, let's figure out what is meant by the term "Heat supply". Heat supply is the supply of heating systems of a building with hot water or steam. The usual source of heat supply is CHP and boiler houses. There are two types of heat supply for buildings: centralized and local. With a centralized supply, certain areas (industrial or residential) are supplied. For the efficient operation of a centralized heating network, it is built by dividing it into levels, the work of each element is to perform one task. With each level, the task of the element decreases. Local heat supply - the supply of heat to one or more houses. District heating networks have a number of advantages: reduced fuel consumption and cost reduction, use of low-grade fuel, improved sanitation of residential areas. The district heating system includes a source of thermal energy (CHP), a heat network and heat-consuming installations. CHP plants produce heat and energy in combination. Sources of local heat supply are stoves, boilers, water heaters.

Heating systems are characterized by different water temperatures and pressures. It depends on customer requirements and economic considerations. With an increase in the distance over which it is necessary to “transfer” heat, economic costs increase. At present, the heat transfer distance is measured in tens of kilometers. Heat supply systems are divided according to the volume of heat loads. Heating systems are seasonal, and hot water systems are permanent.

1. District heating

District heating is characterized by the presence of an extensive branched subscriber heating network with power supply to numerous heat receivers (factories, enterprises, buildings, apartments, residential premises, etc.).

The main sources for district heating are: - combined heat and power plants (CHP), which also generate electricity along the way; - boiler rooms (in heating and steam).

1. Decentralized heat supply

Decentralized heat supply is characterized by a heat supply system in which the heat source is combined with a heat sink, that is, there is little or no heating network at all. If separate individual electric or local heating heat receivers are used in the premises, then such heat supply will be individual (an example would be the heating of the own small boiler house of the entire building). The power of such heat sources, as a rule, is quite small and depends on the needs of their owners. The heat output of such individual heat sources is not more than 1 Gcal/h or 1.163 MW.

The main types of such decentralized heating are:

Electric, namely: - direct; - accumulation; - heat pump; - oven. Small boiler houses.