Description:

Increasing the energy efficiency of buildings can be achieved by increasing the level of thermal protection of the building envelope and improving heating and ventilation systems.

Apartment ventilation system with heat recovery units

Residential building pilot project

S. F. Serov, MIKTERM LLC, otvet@site

A. Yu. Milovanov, LLC "NPO TERMEK"

Federal Law No. 261-FZ “On energy saving and increasing energy efficiency and on introducing amendments to certain legislative acts Russian Federation» provides for a significant reduction in energy consumption by heating and ventilation systems of residential buildings.

The draft order of the Ministry of Regional Development of the Russian Federation plans to introduce standardized levels of specific annual heat energy consumption for heating and ventilation.

As a basic level of energy consumption, indicators are introduced that correspond to building projects completed according to 2008 standards before the federal law came into force. Thus, by Decree of the Moscow Government No. 900-PP, specific energy consumption for heating, hot water supply , lighting and operation of common building engineering equipment in apartment buildings residential buildings

set from October 1, 2010 at the level of 160 kWh/m2 year, from January 1, 2016 it is planned to reduce the figure to 130 kWh/m2 year, and from January 1, 2020 – to 86 kWh/ m 2 year. The share of heating and ventilation in 2010 figures is approximately 25–30%, or 40–50 kWh/m2 year. As of July 1, 2010, the standard in Moscow was 215 kWh/m2 year, of which heating and ventilation accounted for 90–95 kWh/m2 year.

Increasing the energy efficiency of buildings can be achieved by increasing the level of thermal protection of the building envelope and improving heating and ventilation systems.

In basic indicators, the distribution of thermal energy costs in a typical multi-storey building is approximately equal between transmission heat losses (50–55%) and ventilation (45–50%). Approximate annual distribution heat balance

• for heating and ventilation:
• heating of ventilation air – 58–60 kWh/m2 year;
• internal heat release and insolation – 25–30 kWh/m2 year.

Is it possible to achieve the standards only by increasing the level of thermal protection of building enclosures?

With the introduction of energy efficiency requirements, the Moscow government prescribes an increase in the heat transfer resistance of building enclosures to the level of October 1, 2010 for walls from 3.5 to 4.0 deg m 2 /W, for windows from 1.8 to 1.0 deg m 2 / Tue.

Taking these requirements into account, transmission heat losses will be reduced to 50–55 kWh/m2 year, and the overall energy efficiency indicator will be reduced to 80–85 kWh/m2 year.

These specific heat consumption values ​​are higher than the minimum requirements. Consequently, the problem of energy efficiency of residential buildings cannot be solved by thermal protection alone. In addition, the attitude of specialists towards a significant increase in the requirements for heat transfer resistance of enclosing structures is ambiguous., It should be noted that modern heating systems using room thermostats

balancing valves

and weather-dependent automation of heating points.

Things are more complicated with ventilation systems.

Until now, natural ventilation systems have been used in mass construction. The use of wall and window self-regulating supply valves is a means of limiting excess air exchange and does not fundamentally solve the problem of energy saving. In world practice, mechanical ventilation systems with exhaust air heat recovery are widely used. The energy efficiency of heat recovery devices is up to 65% for plate heat exchangers and up to 85% for rotary heat exchangers. mechanical ventilation systems with exhaust air heat recovery units and the need for their qualified maintenance. Imported apartment installations are quite expensive, and their cost for turnkey installation costs 60–80 thousand rubles. for one apartment. At current electricity tariffs and maintenance costs, they pay for themselves in 15–20 years, which is a serious obstacle to their use in the mass construction of affordable housing. An acceptable installation cost for economy class housing should be considered 20–25 thousand rubles.

Apartment ventilation systems with plate heat exchanger

As part of the federal target program of the Ministry of Education and Science of the Russian Federation, MIKTERM LLC conducted research and developed a laboratory sample of an energy-saving apartment ventilation system (ESV) with a plate heat exchanger. The sample is designed as a budget option

installations for economy class residential buildings.

• When creating a budget apartment installation that meets sanitary standards, the following technical solutions were adopted, which made it possible to reduce the cost of ESP:
• the heat exchanger is made of cellular polycarbonate plates; electric heater excluded N
• = 500 W;
• due to the low aerodynamic resistance of the heat exchanger, energy consumption is 46 W; simple automation is used to ensure reliable operation

installations.

The calculation of the cost of the developed ESP is given in the table. Unlike imported analogues, they are not used in the installation electric heaters

neither for protection against freezing, nor for reheating the air. During testing, the installation showed energy efficiency of at least 65%. Frost protection is solved as follows. When the heat exchanger freezes, the aerodynamic resistance of the exhaust tract increases, which is recorded by a pressure sensor, which commands a short-term reduction in flow supply air

until normal pressure is restored.

In Fig. Figure 1 shows a graph of changes in the supply air temperature depending on the outside air temperature at different supply air flow rates. The exhaust air flow rate is constant and equal to 150 m 3 /h.

Pilot project for an energy efficient residential building Based on a residential installation with a heat exchanger, a pilot project for energy efficient residential building in Northern Izmailovo in Moscow. The project provides for apartment supply and exhaust ventilation systems with heat recovery units.

For the innovative installation, the characteristics of MIKTERM LLC are given.

The units are designed for energy-efficient balanced ventilation and creating a comfortable climate in residential premises up to 120 m2. Apartment ventilation is provided with mechanical stimulation and heat recovery from exhaust air to heat the supply air. Supply and exhaust units are installed autonomously in apartment corridors and are equipped with filters, a plate heat exchanger and fans. The installation package includes automation equipment and a control panel that allows you to regulate the air capacity of the installation. Passing through a ventilation unit with a plate heat exchanger, the exhaust air heats the supply air to a temperature t = +4.0 ˚С (at outside temperature Passing through a ventilation unit with a plate heat exchanger, the exhaust air heats the supply air to a temperature air

= –28 ˚С). Compensation for the heat deficit for heating the supply air is carried out by heating devices. The outside air is taken from the loggia of this apartment, the hood, combined within one apartment from baths, toilets and kitchens, after the utilizer is discharged into the exhaust duct through a satellite and discharged within the technical floor. If necessary, condensate drainage from the heat exchanger is provided in sewer riser

, equipped with a drip funnel HL 21 with an odor-locking device. The riser is located in the bathrooms. Regulation of the supply and exhaust air flow is carried out using one control panel. The unit can be switched from normal operation with heat recovery to summer mode without disposal. Switching is carried out using a damper located in the heat exchanger.%.

Ventilation of the technical floor is carried out through deflectors.
According to test results, the efficiency of using an installation with a heat exchanger can reach 67 = The estimated heat consumption for heating the supply air per apartment when using direct-flow ventilation is:· Q·γ·∆ Passing through a ventilation unit with a plate heat exchanger, the exhaust air heats the supply air to a temperature, L C
Q
According to test results, the efficiency of using an installation with a heat exchanger can reach 67= 110 × 1.2 × 0.24 × 1.163 × (20 – (–28)) = 1800 W.
When using a plate heat exchanger, heat consumption for reheating the supply air
= 110 × 1.2 × 0.24 × × 1.163 × (20 – 4) = 590 W.

The volume of supply air is taken to compensate for the exhaust from the bathroom, bathtub, and kitchen. There is no exhaust duct for connection (kitchen equipment exhaust hood from the stove it works for recirculation). The inflow is routed through sound-absorbing air ducts throughout the living rooms. Sewing provided ventilation unit

in apartment corridors with a building structure with hatches for maintenance and an exhaust air duct from the ventilation unit to the exhaust shaft. There are four backup fans in the maintenance warehouse. In Fig. 2 shows a schematic diagram of the ventilation of an apartment building, and Fig. 3 – typical floor plan with placement of ventilation units. Additional costs for installing apartment ventilation with heat recovery from exhaust air for the entire house are estimated at 3 million rubles. Annual heat savings will be 19 800 kWh. Taking into account changes in existing tariffs for thermal energy

The simple payback period will be about 8 years.

1. Literature
2. Decree of the Moscow Government No. 900-PP dated October 5, 2010 “On increasing the energy efficiency of residential, social and public-business buildings in Moscow and amending the Moscow Government Decree No. 536-PP dated June 9, 2009.”
3. Livchak V.I. Increasing the energy efficiency of buildings // Energy Saving. – 2012. – No. 6.
4. Gagarin V.G. Macroeconomic aspects of justifying energy-saving measures when increasing the thermal protection of building envelopes // Construction materials. – 2010. – March.

Gagarin V.G., Kozlov V.V. On the regulation of heat loss through the building shell // Architecture and Construction. – 2010. – No. 3.
Ph.D. E.G. Gacho, Ph.D. S. A. Kozlov,
JSC "Association VNIPIenergoprom", Moscow;
Ph.D. V.P. Kozhevnikov, Belgorod State Technical University

The problem of creating a reliable, sustainable, efficient energy supply for municipal and technological complexes is often replaced by far-fetched dilemmas in the selection of energy sources, persistent propaganda of autonomy of heat and power supply, while actively referring to selected foreign experience. The increase in transaction costs (i.e. the costs of distribution and delivery of fuel and energy resources to consumers) in district heating systems (DH) has given rise to a whole wave of measures to separate networks, the emergence of various autonomous sources of thermal energy of different capacities serving buildings directly, and ultimately to for apartment heat generators. The division of DH systems into autonomous and quasi-autonomous elements and blocks, undertaken ostensibly in order to increase efficiency, often only leads to additional disorganization and confusion.

Lagging construction of heating networks, not always timely input of heat loads for industry and housing and communal services, overestimation of heat loads for consumers, changes in the composition and technology of enterprises led to an unacceptably long (10-15 years) period for bringing turbines to design parameters with full load of extractions. It is precisely the shortcomings of the structural development of heat supply systems (lack of peak units, underdeveloped networks, lagging consumer input, overestimation of calculated consumer loads and focus on the construction of powerful thermal power plants) that have led to a significant decrease in the estimated efficiency of heating systems.

The comprehensive and massive crisis of the country’s life support systems is based on a complex of reasons, including not only the rise in fuel prices, wear and tear of fixed assets, but also a significant change in the design operating conditions, the heat load schedule, and the functional composition of the equipment. In addition, a significant share of the industrial complex and related energy sources, and this is at least 30-35% of total energy consumption, ended up outside of Russia after the collapse of the USSR. A significant number of powerful energy facilities, power lines, pipelines, power engineering plants are located on the territory of neighboring countries (Kazakhstan, Ukraine, Belarus, etc.). The corresponding breaks in technological connections and energy and fuel supply systems served as an additional factor in the deterioration of the operating conditions of life support systems.

The predominance of the industrial load of thermal power plants, which is almost twice as high as the heating load, largely smoothed out the seasonal peaks in municipal heat consumption in cities. A sharp reduction in industrial heat consumption has led to an oversupply of centralized capacities with an increasing role of peak sources and units. The problem is more acute in major cities with a high share of industrial energy consumption, in small cities the system more easily reaches its design parameters.

Foreign experience

Most works actively promoting autonomous heating systems consider it their duty to refer to Western experience, in which there is practically no place for thermal power plants and “giant wasteful heating mains.” Actual European experience suggests the opposite. Thus, in Denmark, largely under the influence of Soviet practice, the basis of the housing infrastructure became precisely district heating. As a result of the implementation of the state program, by the mid-1990s. the share of district heating systems in this country was about 60% of total heat consumption, and in large cities - up to 90%. More than a thousand cogeneration units were connected to the centralized heating system, providing heat and electricity to more than 1 million buildings and industrial structures. At the same time, energy consumption per 1 m 2 only for the period 1973-1983. decreased by half. The reasons for the striking differences between Russia and Denmark lie in the initial investment and the capabilities of operating heating networks. The effectiveness of the Danish example is due to the introduction of new materials and technologies (plastic pipes, modern pumping and shut-off equipment, etc.), which contributed to a visible reduction in losses. In Denmark's main and distribution pipelines they account for only about 4%.

The use of district heating systems for heat supply to consumers in individual countries of Central, of Eastern Europe shown in Fig. 1.

For example, the rationalization of heat supply in East Berlin was based on a phased replacement, reconstruction of highways, installation of metering and control units, and the use of more advanced circuit-parametric solutions and equipment. In buildings before reconstruction, significant “overheating” and unevenness in the distribution of thermal energy were observed both within the volume of buildings and between buildings. About 80% of the buildings were reconstructed, in 10% the heating systems were completely replaced, in the process of internal reconstruction and the transition from single-pipe systems in buildings to double-pipe ones, the areas of heating devices were recalculated, water flow rates in the heating systems of buildings were calculated, and new control valves were ordered. The heating devices were equipped with valves with thermostats, and control valves were installed on the risers of the buildings.

The connection systems as a whole have been replaced with independent ones, a transition has been made from central heating substations to electric substation substation, the coolant temperature has been reduced to 110 °C. Water consumption in the system was reduced by 25%, and temperature deviations among consumers decreased. Building heating circulation networks are used to heat water in DHW system. Currently, there are no limits on the thermal power of sources, there are only restrictions on the throughput of pipelines.

Residents' hot water consumption was over 70-75 l/day; after re-equipping the system, it decreased to 50 l/day. The installation of water meters additionally led to a decrease to 25-30 l/day. In general, a set of measures and design solutions led to a reduction in the cost of heating buildings from 100 W/m2 to 65-70 W/m2. Laws in Germany require a regulatory reduction in energy consumption from 130 kWh/m2 year in 1980 to 100 kWh/m2 year in 1995, and to 70 kWh/m2 year by 2003 G.

Domestic experience

A significant number of works on the installation and adjustment of energy metering systems indicate that maximum heat losses are observed not in networks, as mentioned above, but in buildings. Firstly, these discrepancies were found between the contractual values ​​and the actual amount of heat received. And, secondly, between the amount of heat actually received and the required amount of heat for the building. These discrepancies reach 30-35%! Of course, it is necessary to reduce heat losses during transportation through heating networks, although they are significantly lower.

It is also necessary to note the presence of “overheating” in residential buildings, which is caused by various factors. Buildings are designed for the same loads, but in fact, some consume more heat, others less. Usually people complain little about “overtopping”. And, most likely, if the apartment has its own boiler, the heat savings are not that great, since a person, having become accustomed to such temperature conditions, will provide as much heat as it needs to provide itself with comfortable conditions.

The actual values ​​of specific energy consumption by buildings depending on the thermal resistance of fences are presented in Fig. 2. The upper trend line is based on the actual values ​​of specific energy costs, the lower one is the theoretical balance costs for buildings, with the average standard value for Moscow q = 0.15-0.21 Gcal/m 2 year. The lower trend line in Fig. 2 - functional balance values ​​necessary to maintain standard temperatures in buildings. These values ​​(actual and theoretical) are close in the zone of insufficient thermal resistance R = 0.25-0.3 K.m 2 /W, because in this case, buildings require a significant amount of heat. One of the points close to the lower trend with R = 0.55 K.m 2 /W belongs to a complex of buildings in the Meshchansky district of the Central Administrative District of Moscow, in which a complete flushing of the heating system was carried out. A comparison shows that a number of buildings in the city, being “exempt” from 15% of “overheating”, fully meet modern European energy efficiency requirements.

It can be seen that the actual energy consumption values ​​for buildings with acceptable thermal resistances deviate quite significantly from the theoretical balance curve. The degree of deviation of actual points from the ideal lower curve characterizes ineffective operating modes and irrational waste of energy, and the degree of coincidence characterizes the relative efficiency compared to the optimal base (balance) option. In particular, using the lower base curve, it is advisable to calculate the minimum required heat consumption limits for buildings and structures, based on the actual or predicted temperatures of the heating period.

The identified “overheating” of a significant number of city buildings calls into question some of the recently established stereotypes associated with energy efficiency indicators public utilities. Comparative analysis shows that a number of city buildings consume heat for heating per unit area in terms of the Berlin climate even less than required by European standards of 2003.

Specific implementation of apartment heating projects

Since 1999, Gosstroy of the Russian Federation (now Federal agency for Construction and Housing and Communal Services of the Russian Federation -Rosstroy) conducts experiments on the construction and operation of multi-storey buildings with apartment heating. Such residential complexes have already been built and are successfully operating in Smolensk, Serpukhov, Bryansk, St. Petersburg, Yekaterinburg, Kaliningrad, Nizhny Novgorod. The greatest experience in operating wall-mounted boilers with a closed combustion chamber has been accumulated in Belgorod, where block-by-block construction of houses using apartment heating systems is underway. There are positive

A clear example of their operation in the northern regions - for example, in the city of Syktyvkar.

The city of Belgorod was one of the first cities in Russia (in 2001-2002) to use apartment heating in new multi-apartment residential buildings. This was due to a number of reasons, including, as everyone previously thought, large heat losses in the main and distribution heating networks. And also quite active construction of residential multi-storey buildings, which was primarily due to the influx of money from the North. As a result, in a number of cases, some buildings were equipped with a system individual heating premises.

For apartment heating, boilers of both domestic and foreign manufacturers. Several buildings with similar systems were erected quite quickly and without connecting to heating networks (in the city center, in the southern part). The autonomous heating system in the building looks like this. The boiler is located in the kitchen, from which the chimney pierces the balcony (loggia) and “cuts” into the common chimney, which goes upstairs and rises several meters from the top floor.

The chimney in this case is several times lower than that of a conventional quarterly boiler house; it is natural to expect large ground-level concentrations of emitted components. In specific conditions, it is necessary to compare other factors (fuel economy, reduction in gross emissions, etc.).

Of course, from the point of view of domestic comfort, apartment heating initially seems more convenient. For example, the boiler turns on at lower external temperatures than in the case of using a central heating system (approximately at t nv =0 -–2 °C), because the apartment has an acceptable temperature. The boiler turns on automatically when the temperature inside the room drops, to which the residents set it. Also, the boiler automatically turns on when there is a load on the DHW.

Almost the first important factor here is not the apartment wiring, but the thermal resistance of the building (the presence large loggias, which people additionally insulate). In the absence of proper operating experience, it is still difficult to make an adequate comparison of unit heating costs with an apartment-by-apartment system and in the case of district heating; let’s hope we will have such an opportunity later.

When assessing the financial costs of an apartment heating system during active operation, depreciation of boilers, their total cost (for residents), etc. were not always taken into account.

It is possible to make a correct comparison only under comparable energy conditions. If you look at it comprehensively, then the apartment heating system turns out to be not so cheap. It is clear that individual comfort with the possibility of such distributed regulation always costs more.

What we gained during the operation of apartment heating systems using the example of Belgorod

1. Unheated areas have appeared in residential buildings: entrances; staircases. It is known that for normal operation of buildings it is necessary to ensure heating of all its premises (all zones). For some reason, no one thought about this at the design stage of residential buildings. And already during their operation, they began to come up with all sorts of exotic methods of heating non-residential areas, even electric heating. After which the question immediately arose: who will pay for heating non-residential areas (for electric heating)? We began to think about how to “spread” the fee among all residents, and in what way. Thus, residents have a new cost item (additional costs) for heating non-residential areas, which, of course, no one took into account at the system design stage (as mentioned above).

2. In Belgorod, as in a number of other regions, a certain proportion of housing is purchased by the population for future use. This primarily concerns housing for “northerners”. People, as a rule, pay for everything provided to them housing services, but do not live in apartments or live on short visits (for example, in the warm season). For this reason, many apartments also became cold (unheated) zones, which led to a deterioration in thermal comfort and a number of other problems (the system is designed for general circulation). First of all, a problem arose related to the inability to start a boiler in unheated apartments due to the absence of their owners, and it is necessary to compensate for heat losses (at the expense of neighboring premises).

3. If the boiler does not work for a long time, it requires some preliminary inspection before starting. As a rule, boiler maintenance is carried out by specialized organizations, as well as gas services, but despite this, the issue of servicing individual heat sources in the city has not been fully resolved.

4. Boilers used in apartment heating systems are high-level equipment and, accordingly, require more serious maintenance and preparation (service). Thus, appropriate energy service is required (not cheap), but what if the HOA does not have the funds to carry out this type of service?

Distributed heat control

Both rooftop boiler houses and apartment-based systems are most effective only if it is possible to use natural gas as fuel. As a rule, there is no reserve fuel for them. Therefore, the possibility of limiting supplies or increasing the cost of gas urgently requires the search for new solutions in the future. In the electric power industry, for this purpose, capacities are being introduced at coal, nuclear and hydroelectric power plants, local fuel and waste are being more actively used, and there are promising solutions for the use of biomass. But it is economically unrealistic to solve heat supply issues through electricity generation in the near future. It is more efficient to use heat pump units (HPU), in this case the electricity consumption is only 20-30% of the total heat requirement, the rest is obtained by converting low-potential heat (rivers, soil, air). Today, heat pumps are widely used all over the world; the number of installations operating in the USA, Japan and Europe amounts to millions. In the USA and Japan, air-to-air HPIs are most widely used for heating and summer air conditioning. However, for harsh climates and urban areas with a high thermal load density, it is difficult to obtain the required amount of low-grade heat during peak load periods (at low outside temperatures); in implemented projects, large HPPs use the heat of sea water. The most powerful heat pump station (320 MW) operates in Stockholm.

For Russian cities with large district heating systems, the most pressing question is effective application HPU as an addition to existing district heating systems.

In Fig. 3, 4 show a schematic diagram of a central heating system from a steam turbine thermal power plant and a typical temperature graph of network water. For an existing microdistrict, when 100 t/h of network water is supplied to the central heating station at temperatures of 100/50 °C, consumers receive their 5 Gcal/h of heat. A new facility can receive another 2 Gcal/h of heat from the same network water when cooled from 50 to 30 °C, which does not change the consumption of network water and the cost of pumping it, and is provided without transfer by the same heating networks. The important thing is that, in accordance with temperature chart return network water makes it possible to obtain additional heat precisely at low outdoor temperatures.

At first glance, the use of HPP using return network water as a heat source is uneconomical when taking into account the full cost of heat. For example, operating costs for obtaining “new” heat (at the tariff of Mosenergo OJSC according to the resolution of the Regional Energy Commission of Moscow dated December 11, 2006 No. 51 for heat are 554 rubles/Gcal and for electricity 1120 rubles/MWh) will be 704 rub./Gcal (554x0.8+1120x0.2x1.163=704), i.e. 27% higher than the actual heat tariff. But if the new system allows (there is such a possibility, which is the subject of subsequent consideration) to reduce heat consumption by 25-40%, then such a solution becomes economically equivalent in terms of current operating costs.

Let us also note that in the tariff structure for Mosenergo OJSC, the tariff for heat production is only 304 rubles/Gcal, and 245 rubles/Gcal is the tariff for heat transport (sales markup - 5 rubles/Gcal). But the transfer of additional low-grade heat did not increase the cost of its transportation! If we exclude, which is quite reasonable, the transport component for HPP, then we get the operational component of the cost of “new” heat from HPP is only 508 rubles/Gcal.

Moreover, in the future, it is realistic to introduce different tariffs for heat from thermal power plants - depending on the potential - because a decrease in the temperature of the return network water and additional heat supply ensures the generation of electricity at the thermal power plant by the most effective combined heating method, less heat discharge in cooling towers and increases the throughput of heating mains . Thus, in the works of A.B. Bogdanov, the characteristics of the relative increase in fuel for heat supply from the T-185/215 steam turbine of the Omsk CHPP-5 are given and it is shown that the increase in conditional fuel consumption for the increase in heat load is 30-50 kg/Gcal, depending on the temperature of the network water and on the electrical load of the turbine, which is confirmed by direct measurements. That. with a constant electrical load, the additional fuel consumption at a thermal power plant for heat supply is 3-5 times lower than from hot water boilers.

The most effective application in climate systems is the use of water-air HPI, i.e. not heating water for the heating system, but obtaining air of the required parameters is a real possibility of creating comfortable conditions even with unstable operation of the heating network, where temperature and hydraulic conditions cannot be maintained, using the amount of heat from the source and converting it into the quality of heat supply. At the same time, such a system solves the issue of air cooling in summer time, which is especially important for modern office and cultural centers, elite residential complexes, hotels, where a completely natural requirement - air conditioning - is often extremely ineffectively provided by spontaneously equipping the premises with split systems with external units on the facade of the building. For facilities with the need to simultaneously heat and cool the air, a ring heating and air conditioning system is used - a solution known in Russia from 15 years of experience in operating the Iris Congress Hotel in Moscow; such solutions are currently being implemented at other facilities. The ring system is based on a circulation circuit with a water temperature of 20-30 °C; Consumers have water-to-air heat pumps installed, which cool the air in the room and pump its heat into the common water circuit, or pump heat from the common (water) circuit into the room, heating the air. The water temperature in the water circuit is maintained within a certain range known methods- this is the removal of excess heat in the summer using a cooling tower, heating the water in the winter with network water. The design power of both the cooling tower and the heat source is significantly less than would be required with traditional air conditioning and heating systems, and the construction of buildings equipped with such systems is less dependent on the capabilities of the heat transport system.

Instead of a conclusion

Today we can draw an unambiguous conclusion - the euphoria that was at the initial stage of introducing apartment heating systems in multi-apartment residential buildings is no longer there. Apartment heating systems were installed because the pace of construction was quite intense, and there was the possibility of introducing new projects of this kind (although perhaps not always deliberately). Nowadays, a complete abandonment of these systems has not occurred; there is an understanding of the pros and cons of both autonomous devices and central heating systems.

It is necessary to make maximum use of the available capabilities of district heating

systems of large cities, develop them, including measures government regulation to ensure the commercial efficiency of district heating.

Imbalances in energy consumption within a metropolis can be predicted and neutralized with an integrated territorial approach to the urban economy as a single life support mechanism, if one does not see in it only industry structures and interests, and does not allocate and privatize private isolated areas for profit, without maintaining a state of full efficiency and proper technological upgrading. It is obvious that no private solutions for autonomous energy supply will save the situation. It is necessary to increase the sustainability of energy infrastructures using a variety of energy technology units and systems. Interconnection and coordination of modes of production and consumption of energy resources does not in any way imply the abandonment of unified urban life support systems; on the contrary, they are coupled with possible autonomous units in such a way as to ensure maximum energy efficiency, reliability and environmental safety.

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If we consider a residential building as an energy-consuming object, then the share of heat loss in it is winter period is: through non-insulated or broken windows and entrance doors - 24, through walls - 26, through the basement, ceilings, staircases -11, through ventilation holes and chimneys -39% 2.

Heat loss occurs not only through the walls of the building. They can occur during accidents on highways and at thermal units residential buildings.

A large amount of thermal energy is lost due to poor-quality construction: cracks in window frames, seams between panels, roofs, etc., as well as in houses with heating devices installed in the walls (30% more than with conventional heating devices). Up to 15-20% of thermal energy is lost in heating networks, as evidenced by green grass growing above heating mains in winter.

This situation with the use of heat in everyday life was a consequence of the existing situation in our former great country the concept that our country will have enough mineral resources, including fuel and energy resources, not only for the present, but also for future generations. And when designing residential buildings, the cost of their operation was never taken into account, which is why relatively cheap, but cold houses were built.

Approximately 65% ​​of thermal energy is spent on household needs in the Republic of Belarus. At the same time, heat losses during the production and transmission of thermal energy in heating boiler houses of the republic reach 30%. For 1 m 2 of heated area in our country, 2 times more equivalent fuel is consumed than in Germany and Denmark.

The annual consumption of thermal energy in our country for heating and ventilation is 1 m2 total area in a 5-story building it is 150-170 kW, in Scandinavian countries - 70-90 W. In the West, after the energy crisis of 1972-1973 and 1995, advanced European countries reduced the consumption of thermal energy for heating residential buildings by 2 times. And this is not only savings Money, but also, most importantly, a change in the very thinking of citizens and leaders.

According to sanitary standards 3, hot water must be supplied to apartments at a temperature not lower than 50 °C, but it is supplied at a temperature of 37... 38 °C. The air temperature in the apartment should be maintained at 18... 20 °C (comfort zone), and in the kitchens 4 - 16... 18 °C. The family pays only 16-17% of the total cost of heating the house, and of the cost of the generated heat and electrical energy- only 20%. With such an existing system of payment for consumed heat and electricity, it will be difficult to achieve a radical change in the improvement of business in the household sector until residents are economically interested in saving thermal energy. And to do this, it is necessary to change the psychology of all citizens in relation to saving heat, water, and gas. The entire European experience shows that only a well-thought-out continuous system of upbringing and education makes it possible to obtain real results in energy saving in the domestic sector and the industrial sector. In the West, particularly in Germany, 78% of all housing receives heat from local boiler houses, the unit cost of which is 0.05 DM/kW * h, while with centralized heating this figure is 0.08. The experience of decentralized heat supply in our country shows its high efficiency. Local boiler houses built in the capital (Hotel "Belarus", several residential buildings, etc.) pay for themselves in 1.5-3 years 5 . In 1998, 77 million Gcal of thermal energy was produced to meet the country's needs, and in 1999 - 70 million Gcal of thermal energy. In order to satisfy the republic's needs per year, 50 million Gcal is enough.

Attaching great importance to energy saving in the housing and communal sector of the economy, the President of the Republic of Belarus A.G. Lukashenko gave instructions on June 13, 2001 to the regional executive committees and the Minsk City Executive Committee, together with interested ministries and departments, to implement measures to increase the efficiency of housing construction, reduce the costs of developing engineering and transport and social infrastructure through densification of buildings, the use of local heat sources, autonomous heating systems, water supply and sewerage."

One of technical solutions reducing the heating supply network and saving thermal energy is the decentralized generation of heat using automated, autonomous, including roof-mounted, boiler houses (powered by gas fuel. The advantage of this type of heat supply is the following: the ability to build a boiler house that meets the needs of a particular building; saving of land; saving energy due to the absence of losses; the ability to control heat and fuel; setting the required heat consumption mode depending on the length of the working day and the outside temperature; high efficiency (90%) of boiler installations; low temperatures and coolant pressure, which increases the durability of heating systems.

Heating systems of residential and public buildings are one of the most significant consumers of thermal energy. Thermal energy consumption for these purposes accounts for more than 30% of the energy resources consumed by the national economy. At the same time, apartment buildings built in 1950-1960 spend from 350 to 600 kW * h per 1 m 2 for heating needs. For comparison, we point out that this figure is 260 kW * h in Germany, and 135 kW * h 3 in Sweden and Finland.

The most promising areas of energy saving are the introduction of autonomous heat and power supply systems, installation underfloor heating, as well as installations using renewable energy sources and heat exchangers.

Autonomous heat supply systems in the form of mini-boiler houses are becoming promising V in places where it is used as fuel natural gas. From an environmental point of view, they also help improve the condition of the air basin, because due to a decrease in the amount of gas burned, the amount of flue gases is reduced, and gas emissions contain 2-3 times less harmful substances per 1 m 3 than large district boiler houses. But decentralized heat supply based on small individual boiler houses is effective with low heat load density (one- and two-story buildings in rural and other populated areas).

Naturally, with the existing developed district heating networks, it is unreasonable to talk about a widespread transition to autonomous boiler houses. But their implementation is possible in the following cases:

During the construction of new and reconstruction of old buildings in areas where laying heating networks is technically impossible;

To provide heat to facilities that do not allow fluctuations in heat supply (schools, hospitals), or to consumers who suffer large economic losses due to lack of heat (hotels);

When providing heat to consumers located at the end sections of existing heating networks and experiencing a lack of heat due to the low throughput of heating networks or insufficient! pressure difference between forward and return lines;

When constructing facilities in small cities, where centralized heat supply is poorly developed, and individual facilities are introduced separately.

The main element of an autonomous power plant is combined gas wall-mounted water heaters, in the housing of which there is a silent circulation pump and a membrane expander. Hot water from the water heater metal pipes, laid in concrete floor preparation or in baseboards special design, separated into rooms.

Experience in operating a 72-apartment nine-story residential building in microdistrict No. 17g. Gomel with this fundamentally new heat supply system for our country, developed by the Gomelgrazhdanproekt Institute, showed its reliability and efficiency. So, in November 1999, living in three-room apartment a family of 4 people used 150 m 3 of gas for heating, hot water supply and cooking; and a third of this amount was spent directly in the kitchen. Calculations showed that with a traditional heat supply system for a similar apartment from a common house system with a connection to external source For heating and hot water supply purposes, about 500 m 3 of gas would be required.

The high efficiency of the proposed apartment heating system is achieved thanks to:

Relatively high efficiency gas water heaters(“85%)”;

Elimination of heat loss outside the apartments;

No excessive heat consumption during off-season periods (according to available data, it is up to 20%);

Possibilities for apartment-by-apartment metering and room-by-room temperature control inside the apartment.

In addition, the apartment heating and hot water supply system has significantly reduced the number of metering devices. Instead of the currently used gas, heating, hot and cold water meters, it is enough to install only two devices for metering gas and cold water consumption. In addition, there is no need to lay external heating networks. Perhaps one of the most important advantages of this heating system over the traditional one is that it allows the apartment owner to create a comfortable air temperature not by opening the window and window sash, but by using a manually controlled adjustment valve or an automatic thermostatic head, thereby saving your money for heating the apartment and state energy resources.

Savings in heat consumption due to the above advantages of apartment heating reaches 30% per year.

The construction of residential buildings with a similar engineering support system is highly justified in areas of existing urban development where there are no reserve capacity existing centralized heat supply sources.

The experience of operating autonomous boiler houses shows that they are reliable and economical. When supplied with heat from these boiler houses, the consumer receives thermal energy at tariffs that are 3 times lower than the current ones. Due to this, the construction of such boiler houses pays for itself in almost one season.

In all industrial and energy sectors developed countries There has been a very rapid increase in the use of electric heating, usually carried out by laying heating cables in the floor. The use of electric heating is permitted by SNIP 2.04.05-91. For rooms with constant occupancy, it is established that the average temperature of the heated floor should not exceed 26°C, and for paths around swimming pools - no more than 30°C. One of such electric heating systems is the Teplolux cable system. It is installed in the thickness of the floor, which turns the entire heated surface into a heat source, the temperature of which is only a few degrees higher than the air temperature. This system, like others like it, is used as the main one in detached buildings, cottages and in cases where it is not possible to connect central water heating. It can be used as an additional heating system (together with others) to obtain room temperature.

A completely new way to heat rooms for various purposes developed at BITU by Professor V.P. Lysov. The polymer heating electrical wiring he created, consisting of hundreds of the finest polymer fibers, processed using an original technology with a special solution and connected into a bundle, provides, at the same power consumption, a much higher temperature increase than that of a metal conductor, since the fibers constantly heat each other. This wiring, or rather, a set of wires, is laid out according to the diagram on a prepared concrete base and cemented. You can place wires under tiles, various linoleums, carpeting, under the boardwalk and parquet. In any case, the floor temperature recommended by doctors will be 25 ° C, and the air temperature will be 20... 22 ° C. For reliability, you can also connect an automatic thermostat to the network.

The costs of heating and operating this method are 1.5-2 times lower compared to other known methods, including similar foreign underfloor heating systems that use metal conductors. But the disadvantage of metal conductors is the accompanying eddy currents that are undesirable for the body. The polymer conductor generates an electromagnetic field 2-10 times weaker, which does not come close to the lower limit.

The scope of application of this heating method is very wide: houses, apartments, offices, livestock buildings, etc. Its advantages are appreciated by many owners own houses, managers, but the managers of state farms are especially pleased, where the new product has been used for 3 years and, in addition to saving energy resources for heating, largely contributes to the preservation of livestock numbers and their weight gain. According to studies conducted by scientists from the BelRussian Research Institute of Animal Husbandry in animal husbandry areas with heated floors, it has been established that the safety and weight gain of piglets increases, while electricity consumption is reduced from 250 W with lamp heating to 120-130 W with heated floors per 1 livestock place. This method of heated floors has been introduced in many farms in the country.

The ease of installation and operation of heated floors, low cost and energy consumption in comparison with traditional heating technologies were appreciated by the owners of more than 1.5 thousand apartments and private houses, country houses and garages, offices and shops in the republic, increasing their comfort of living and work. It should be added to this that the cost of arranging heating is 10-12 US dollars and is compensated by the savings achieved over 5-6 months of operation in the cold season.

To provide public, residential and industrial premises with cheap heat using local fuels, it is economically profitable to use air heating based on heat generators.

In this article we continue the topic we started about the heating system of a private house with our own hands. We have already learned how such a system works, talked about which type to choose, now let’s talk about how to increase efficiency.

So, what needs to be done to make its effectiveness higher.

We need the coolant inside to move in the direction we need and in the right quantity at a higher speed, while giving off more heat. The liquid in the system must move faster not only through the pipeline, but also through the batteries connected to it. Let me explain the principle of operation using the example of a two-pipe system with bottom wiring.

In order for water to flow into the batteries connected to the pipe, it is necessary to make a brake at the end of this supply pipe, that is, increase the resistance to movement. To do this, at the end (the measurement must be taken from the entrance to the outer radiator) we install a pipe of smaller diameter.

In order for the transition to be smooth, they must be installed in this order: If the inlet to the radiator is 20 mm (standard for new batteries), then the supply pipe (outlet for radiators) must be at least 25 mm.

Then it smoothly, after 1-2 meters, passes into a pipe whose diameter is 32 millimeters, then according to the same scheme - 40 millimeters. The rest of the distance of the system or its wing will be a supply pipe with a diameter of 40-60 mm or more.

In this case, when the boiler is turned on, the coolant begins to move through the system and, encountering resistance on its way, will begin to move in various other directions (to the radiators), equalizing the overall pressure.

We have thus increased the efficiency of the supply pipe and the first half of the system. And what happens in the other half, which is, as it were, a reflection of the first.

And since this is a mirror reflection, then the processes in it occur exactly the opposite: in the supply return pipe, the pressure decreases (due to a decrease in the temperature of the liquid and an increase in diameter) and a suction effect appears, which helps the initial pressure to increase the speed of water movement not only in the pipeline, but also in heating radiators.

By increasing efficiency, you will not only make your home warmer, but also save a lot of money.

Video: Warmth in the house - heating: Increasing the efficiency of a water heating battery / radiator

Spurred on by the decisions of the last congress of the CPSU Central Committee, the Soviet people accepted with joy and inspiration the decision of the Supreme Soviet of the USSR on the next kidnapping of the lumpen proletariat and the liquidation of pensioners and disabled people as a class, at a rate of no less than 10% per year. (Stormy applause)

In our society, comrades, a vicious practice has developed - to live until retirement age without having money. But it’s not so scary, it’s much worse that pensioners, disabled people and veterans have the audacity to survive. And the reason for this is benefits. As a way out of this situation, it is necessary to introduce monetization everywhere, which would not allow pensioners to increase in number. (Applause turning into ovation).

Everyone who finds themselves out of work hears something like this speech. And no matter how rosy the media statements may be, everyone understands that something is wrong here. It is impossible to solve such a complex problem with such a primitive one-step approach as monetization. It's the same as getting checkmate in one move in chess. And if you try to analyze the consequences, then there will be no rainbows at all. It would be naive to believe that a crowd of economists, who know how to steal millions offshore without consequences, could not come up with anything better than direct distribution of money. And here doubts begin to creep in that some uncle really cares about your well-being. In order to understand what awaits us, it is not at all necessary to be a seer, it is enough to simply have a memory. Remember what the heating of your apartment was like twenty years ago and compare it with today. Remember what part of a salary of 100 rubles. did you pay then and how much do you pay now, earning your 100 USD? Anticipating objections about subsidies, I will say right away - nonsense. During the Soviet period, rent was subsidized only in dorms, military personnel, large families and veterans. The rest paid the most I don’t want, from 20 to 40 rubles. for a family of 4 people in a three-room Khrushchev house without hot water (bucks then cost 48-65 kopecks, a ton of coal - 9-12 rubles). But, be that as it may, life has become better now, life is more fun now. If you don't believe me, turn on the TV. It is enough to touch the heating radiators, look at the thermometer in your apartment, or simply take off your felt boots to feel all the charm of the cool and refreshing breath of new life. This is not the stinking warmth of past, stagnant times.

The bulk of the population generally prefers, without further ado, to plug in an electric heater and not create problems for themselves or the stokers. But for this you need a heater and money. Few of the stoker brethren will dare to raise the temperature in the boiler above 70-75C. And they can be understood too. Iron is iron and doesn’t like extreme sports. Few people would dare to take the risk of stopping the fireplace in the middle of winter for repairs, although the specifications of any water boiler allow the temperature to be increased up to 100C. Limit 120C at a pressure of 0.7 atm.

That's why we have what we have. You can do strikes, but the temperature of the water supply to your house will not be higher than 70C, and therefore there will be no heat in your apartment either.

Meanwhile, there is a way to “make” batteries heat your home and increase their efficiency by two or three times.

The method is simple and not so labor-intensive. You need to install the fan so that it blows along the battery. Even an ordinary fan from a computer power supply is enough to keep the temperature in the room 3-5C higher than usual. This is equivalent to connecting an additional 1 kW electric heater, or adding a dozen more sections to your standard 6-8 section battery.

To do this, we bend a U-shaped plate out of tin and bend the edges so that the plate is firmly held by the edges of the battery. In the middle of the plate, cut out a hole for air and punch 4 small holes for the fan mount. We secure the fan with 4 self-tapping screws. The fan from the computer is designed for 12 V power supply direct current. So a power supply from an old tape recorder and a battery charger will do, but you can make a homemade one with voltage regulation. Then it will be possible to regulate both the fan speed and the noise that comes from it. We attach this structure to the battery, as close to the floor as possible, connect it and wait... for spring))). The costs of this hyperboloid together with a home-made power supply are comparable to the cost of 100 kW/h of electricity. Power consumption does not exceed 4 watts. If the power supply has adjustable output voltage, then by adjusting the fan speed, you can regulate the temperature in the room.

The most important thing is that by using such a lotion for your battery, you reduce the dependence of the temperature in your room on the mood of the fireman.

For those who decide to do business with this, I would advise making a circuit that automatically turns off the fan when the air temperature in the room is higher than the temperature of the battery. This is in case the boiler in the stoker is stopped for cleaning.

In the summer, this same unit can be used as an ersatz air conditioner. And one more plus: since the rate of rotting (rusting) of main pipes directly depends on the water temperature, in this way it is possible, by reducing the water temperature to acceptable limits, to extend the service life of pipelines and boilers.

You can think about business, savings and possible income from this yourself...