Heat pump installations in Russia. Heat pump installations

Heat pump units and installations should be considered as devices that carry out full cycle refrigerant circulation and control devices, including a drive. Moreover, heat pump units include compact, ready-to-work units, and heat pump units include complexes consisting of several separate devices or units. Depending on the type of load from the source and receiver, heat pumps can be classified in accordance with Table. 1.2.

It has been established that due to the same thermodynamic circular cycle refrigeration units and heat pumps and a slight discrepancy between the temperature intervals of the equipment, heat pumps should be selected directly from the range that is used for refrigeration equipment with some modifications, and only in some cases the development of special units is required.

Table 1.2.

Thermoelectric heat pumps have not yet received widespread use due to the low conversion factor.

Compression warmth pumping units

K TN low power include small water heaters and window air conditioners that include heat pumps. In general, heat pumps designed primarily for the production of heat at a power of 2 ... 3 kW cannot compete with simple electric heaters (with an electric support heater) due to high unit costs. Only units designed primarily for refrigeration and heat generation have, thanks to their easy switching, practical value. These are, in particular, window air conditioners with switching (Fig. 1.29).

Such units typically consist of a sealed case chiller, an evaporator and a forced air condenser. By means of a four-way valve, they can switch to heat pump, that is, to provide space heating. Each fan has a device for switching the operation of the evaporator to the condenser, and to the movement of indoor and outdoor air.

Rice. 1.29. A - communication scheme; b- the scheme of inclusion of the conditioner; in - heat pump switching circuit; / -capacitor; // - Throttle; W compressor; IV- evaporator

Thermal power is 1.5 ... 4.5 kW. The conversion factor at a room temperature of 21°C and an outside temperature of 7.5°C rarely exceeds 2.

Part of the high-capacity air conditioners intended for general industrial buildings is also made with a switch to work according to the heat pump scheme.

Compression heat pumps can also be driven by heat engines. In this case, the entire unit consists of a compression heat pump and a heat engine. The conversion of the chemical energy of the fuel into heat takes place directly inside the heat engine (for example, the Stirling engine). In the engine, according to the thermodynamic circular cycle, part of the heat is converted into mechanical energy, which drives its own compression heat pump, thereby increasing the useful temperature level of the low-temperature environment or waste heat. Waste heat from the engine can also be used. The waste heat exchanger, depending on the temperature conditions, is connected in parallel or in series with the condenser of the compression heat pump or the heat is supplied to special consumers.

As drives, in principle, heat engines of all types can be used, but the most convenient gas and diesel engines, because they run on natural gas and oil - high-quality carriers of primary energy used for heating. The heat generated by such a motorized heating system can cut the primary energy consumption by about half compared to in the usual way heat generation from fuel combustion.

A conversion factor of 1.8 ... 1.9 can be achieved.

Absorption heat pump units

According to the degree of aggregation, APTs are divided into aggregated (with a constructive combination of all elements into one or more blocks) and non-aggregated (with separately executed APT elements). Aggregated include lithium bromide and APT.

Depending on the scheme for including APT in technological processes various industries they can be divided into stand-alone, independent of the process flow diagram, and built-in - with the combination of a part of the APT cycle with the process.

The number of absorption heat pumps produced so far is not rich, but high transformation ratios have already been achieved. At the same time, absorption heat pumps can more fully meet the special conditions of heat sources and drive energy than compression ones.

In Germany, for example, absorption heat pumps with a heat output of 1 ... 3 MW are produced. The transformation ratio depends on the operating temperature and the evaporating temperature. For small installations it is not possible to achieve high performance (WITH,< 1.5). AT different countries work is underway to improve small absorption heat pumps.

Usage: in installations for heating and cooling rooms with permanent ventilation. The essence of the invention heat pump installation contains a heat exchanger 1, an evaporator 4, an injector-absorber 6, a pressure-separating tank 9 and a liquid pump 7. The evaporator 4 and the injector-absorber 6 are connected by at least one capillary 5. The evaporator 4 is made of three cavities and is filled with a porous body 16. 5 z.p. f-ly, 2 ill.

The invention relates to heat pump installations based on absorption units, in particular to installations for heating and cooling rooms with permanent ventilation. The operation of all heat pumps is based on the thermodynamic state and the parameters that determine this state: temperature, pressure, specific volume, enthalpy and entropy. All heat pumps work by supplying heat isothermally at low temperatures and isometrically dissipating at high temperatures. Compression and expansion is performed at constant entropy, and the work is done from an external engine. A heat pump can be described as a heat multiplier that uses low-grade heat from various heat-producing media such as ambient air, soil, groundwater, wastewater, etc. Currently, there are many different heat pumps with different working fluids. This diversity is caused by the existing restrictions on the use of one or another type of heat pump, which are imposed not only by technical problems, but also by the laws of nature. The most common are pumps with mechanical vapor compression, followed by absorption cycle and double Rankine cycle pumps. Pumps with mechanical compression are not widely used due to the need for dry steam, which is caused by the mechanics of most compressors. The ingress of liquid along with steam to the compressor inlet can damage its valves, and the flow of a large amount of liquid into the compressor can generally disable it. The most widely used pumps are absorption type. The process of operation of absorption plants is based on the successive implementation of thermochemical reactions of absorption of the working agent by the absorbent, and then the release (desorption) of the absorbent from the working agent. As a rule, a working agent in absorption plants water or other solutions that can be absorbed by the absorbent serve as absorbents, compounds and solutions that easily absorb the working fluid can be used: ammonia (NH 3), sulfuric anhydrite (SO 2), carbon dioxide (CO 2), caustic soda (NaOH) , caustic potash (KOH), calcium chloride (CACl 2), etc. Known, for example, is a heat pump unit (ed. St. USSR N 1270499, class F 25 B 15/02, 29/00, 1986), containing an absorption refrigeration unit with a refrigerant circuit, a condenser, a subcooler, an evaporator, a dephlegmator and a regenerative heat exchanger, as well as the heating water circuit passing through the condenser, the ventilation air line passing successively through the absorber and the subcooler, the heating water circuit is made closed and a dephlegmator is additionally included in it. The plant additionally contains a two-cavity heat exchanger - subcooler, which is connected by one cavity to the refrigerant circuit between the subcooler and the evaporator, and the other - to the ventilation air line in front of the absorber. The described installation is cumbersome and metal-intensive, as it has components and systems operating at elevated pressure. In addition, achieving high energy indicators in a known installation, ammonia and its aqueous solutions, which are toxic and corrosive, are used as a coolant. The most efficient heat pump installations are of the absorption-injector type. Known thermal plant(ed. St. USSR N 87623, class F 25 B 15/04, 1949), including an ammonia steam generator (evaporator) filled with a highly concentrated aqueous ammonia solution, with a coil of steel pipes located inside it, into which steam is supplied low pressure, which serves to evaporate ammonia, absorbers high pressure (injectors), pumps, tubular heat system, high steam generator, low pressure steam condensate heater, cooler serving as a heater at the same time. The described installation makes it possible to increase the steam pressure at a high value of thermal efficiency due to the fact that the absorber of the installation has injectors that serve to increase the pressure obtained in the ammonia vapor generator with the help of a lean solution supplied by a pump from the generator. However, in the described installation, aggressive media are used, which requires the use of special materials of high corrosion resistance. This greatly increases the cost of installation. The aim of the invention is to create a simplified, environmentally friendly, economical installation with high energy performance. This problem is solved by the fact that a heat pump installation containing a heat exchanger, an evaporator, an injector-absorber, a liquid pump, a pressure-separating tank, an evaporator and an injector-absorber, which, according to the invention, are interconnected by at least one capillary, and the evaporator is made of three-cavity, one cavity of which is connected to the heat exchanger by a ventilation air line, the other is filled with a coolant, separated by a vacuum cavity connected to an injector-absorber, and the evaporator contains a porous body placed simultaneously in all these cavities. The design of the connection between the evaporator and the injector-absorber in the form of a thermodynamically discontinuous system connected by at least one capillary makes it possible to conduct the process of obtaining heat in a region far from thermodynamic equilibrium, which significantly intensifies heat and mass transfer in the system under consideration. It is possible to connect the evaporator and the injector-absorber with several capillaries. This will enhance the effect of heat and mass transfer in the system under consideration. The execution of the evaporator with three independent, separated cavities and with a porous body placed simultaneously in all three cavities allows the formation of a developed mass transfer surface between the coolant and air (approximately 100-10000 cm 2 in 1 cm 3), due to which intensive evaporation of the coolant and saturation of the air with it, accompanied by a large absorption of heat coming from the heat-generating medium. It is advisable that the capillary has a diameter equal to the mean free path of the coolant molecules in the vapor phase at a residual pressure created by the injector-absorber and a temperature equal to the temperature of the liquid coolant, and a length equal to 10-10 5 diameters of the capillary. This ensures intensive mass transfer of the coolant in the direction only from the evaporator to the injector-absorber. It is advisable to make a porous body from two types of pores, the surface of some of which is wetted, while others are not wetted by the coolant. In this case, the porous body is simultaneously permeable to liquid and air and will allow the formation of a more developed mass transfer surface between the coolant and air inside the porous body. This greatly intensifies the evaporation process. The evaporation rate in the evaporator of the porous body structure described above reaches a value close to the evaporation rate in absolute vacuum. It is advisable to bring at least one heat pipe to the evaporator, one end of which is placed in a porous body, and the other in a heat-generating medium, for example, in the ground. This will intensify the heat exchange between the evaporator and the heat-generating medium. The outlet pipe of the gas-steam mixture of the pressure-separating tank can be connected to a heat exchanger, which is also a condenser in the described installation. This will provide heating and, consequently, a decrease in the humidity of the ventilation air sucked into the evaporator from the environment, thereby intensifying the process of evaporation of the coolant in the evaporator. It is advisable to connect the pressure-separating tank to a heat exchanger, which is simultaneously a condenser in the described installation. This will provide heating and, consequently, a decrease in the humidity of the ventilation air sucked into the evaporator from the environment, thereby intensifying the process of the coolant evaporator in the evaporator. The evaporator cavity filled with heat carrier can be connected to the heat exchanger by a heat carrier condensate line. This will avoid losses of the coolant with the vapor-gas mixture separated in the pressure-separating tank and ensure constant replenishment of the coolant in the evaporator. Figure 1 shows a diagram of the proposed heat pump installation; figure 2 the evaporator placed in it a porous body and a heat pipe. The inventive heat pump installation contains a heat exchanger 1 (figure 1) with nozzles 2, 3, respectively, for supplying ventilation air and an air-steam mixture, an evaporator 4 connected to the heat exchanger 1 by a gas-liquid line 5, which is two separate pipes, and with an injector-absorber with a capillary 7 connected to the suction line of the injector-absorber. The capillary must have a diameter equal to the mean free path of the coolant molecules in the vapor phase at the residual pressure created in the injector-absorber 6 and a temperature equal to the temperature of the liquid coolant. The length of the capillary line should be 10-10 5 of the capillary diameter. The injector-absorber 6 is installed on the pressure line of the liquid pump 8 and is connected to the pressure-separating tank 9, filled to 2/3 of its volume with a liquid heat carrier. The pressure-separating tank is connected by line 10 to heat exchanger 1 through branch pipe 3 and line 2, designed to remove the liquid heat carrier, with heating devices 12, which are connected to the suction line of liquid pump 7. Evaporator 4 is made of three independent cavities 13, 14 and 15 ( figure 2). The cavity 13 is connected to the air supply pipe from the heat exchanger. The cavity 15 is filled with a liquid heat carrier and is connected to the heat carrier condensate supply pipe from the heat exchanger 1, which is also a heat carrier vapor condenser. This makes it possible to avoid losses of the coolant with the gas-vapor mixture, which is separated from the liquid coolant in the pressure-separating tank 9. The cavity 14 is connected by means of a capillary line 7 to the suction line of the injector-absorber 6, inside the evaporator 4 there is a porous body 16, made in the form of a thick-walled a cylinder containing two types of pores - the surface of one type of pores is well wetted by the coolant, the surface of the other type of pores is not wetted by the coolant, but is permeable to air. The material for the porous body is selected depending on the coolant, which can be any non-aggressive liquid with a boiling point at a pressure of 1 atm not higher than 150 o C, for example, water, alcohols, ethers, hydrocarbons and their mixtures, consisting of two, three or more components, mutually soluble. The coolant is chosen depending on which room is required to be heated by the installation, on climatic conditions and other factors. The porous body 16 is placed inside the evaporator in such a way that its surfaces are in contact with all three of these cavities. To the evaporator 4 summed up the heat pipe 17, one end of which is placed in the porous body 16, and the other in a heat-generating medium, such as soil. There can be several heat pipes, which will increase the supply of heat from the heat-containing medium to the evaporator and thereby enhance the process of evaporation of the coolant. Heat pump installation works as follows. Air from the atmosphere through the pipe 3 of the air supply due to the rarefaction created by the injector-absorber in the evaporator 4 is sucked into the heat exchanger 1 and through the gas-liquid line 5 through the air pipe enters the chamber 13 of the evaporator 4. Inside the porous body 16, the heat carrier intensively evaporates and saturates it air vapor. In this case, the heat of the heat-generating medium, such as soil, is absorbed, which is supplied to the evaporator through heat pipes 17. The evaporation rate of the heat carrier inside the porous body reaches a value comparable to the evaporation rate in absolute vacuum of 0.3 g/cm 3 s, which corresponds to heat flow 0.75 W/cm 2 porous body. The air saturated with coolant vapor is sucked into the injector-absorber 6 through capillary 7, and the coolant is supplied here by a liquid pump 8 from heating devices 12 under pressure and mixed with the vapor-air mixture, forming an emulsion, which is air bubbles and coolant. In this case, vaporous moisture is absorbed by the liquid with the release of heat equivalent to the heat absorbed in the evaporator. The released heat is used to heat the coolant. The emulsion formed in the injector-absorber 6 enters the pressure-separating tank 9, where it is separated into an air-steam mixture and a liquid heat carrier. From the pressure-separating tank 9, the heated coolant flows by gravity into the heating devices 12 and again to the suction line of the liquid pump 8, thus completing the cycle of the liquid coolant. The air-steam mixture from the pressure-separating tank 9 through line 10, due to a small excess pressure created in the pressure-separating tank 9, enters the heat exchanger 1 through the pipe 3. In the heat exchanger 1, the suction atmospheric air and condensation of the coolant vapors, which separately enter the evaporator 4. Thus, the inventive heat pump unit has high energy performance, without the use of aggressive, environmentally harmful coolants, which makes it safe to operate. Water can be used as a heat carrier. For heating rooms, buildings in harsh climatic conditions, the evaporator can be filled with low-boiling coolant for more intense evaporation, and after heating system water can be passed through. For heating, for example, garages, when constant heating is not required even in winter, it is advisable to use alcohols or solutions that have a low freezing point as a heat carrier, which will prevent the system from freezing during the shutdown of the installation. The use of non-aggressive heating fluids eliminates the need to use special materials and alloys in the manufacture of the unit. Some units of the installation, such as a pressure-separating tank, connecting pipelines can be made of plastics, rubber and other non-metallic materials, which will significantly reduce the metal consumption. The installation is technically simple in execution and operation, does not require large energy consumption. The heat generating unit is compact and can be placed in a small area and can be used both for heating large rooms, buildings, and small buildings, as well as garages, and when working in a refrigeration cycle to cool basements in the summer. The possibility of a wide choice of the type of heat carrier allows the use of the unit in any climatic conditions. All this determines the low cost of the installation, the safety of its operation and accessibility for a large number consumers.

Claim

1. A heat pump unit containing a heat exchanger, an evaporator, an injector-absorber, a liquid pump, a pressure-separating tank, characterized in that the unit is equipped with a ventilation air line, at least one capillary and a porous body, and the evaporator is made three-cavity, one cavity of which is connected with a heat exchanger by a ventilation air line, the other is filled with a coolant and the third evacuated cavity is connected to an injector-absorber, while the porous body is placed in all three cavities, and the evaporator and the injector-absorber are interconnected by at least one capillary. 2. Installation according to claim 1, characterized in that the capillary has a diameter equal to the free path of the coolant molecules in the vapor phase at a residual pressure created in the injector-absorber and a temperature equal to the ambient temperature, and the length of the capillary is 10 10 5 its diameter. 3. Installation according to claim 1, characterized in that the porous body is formed by pores of two types, the surface of some of which is wetted, while others are not wetted by the coolant. 4. Installation according to claim 1, characterized in that at least one heat pipe is connected to the evaporator, one end of which is placed in a porous body, and the other in a heat-generating medium. 5. Installation according to claim 1, characterized in that the pressure-separating tank is connected to a heat exchanger. 6. Installation according to claim 1, characterized in that it is provided with a coolant condensate line, through which the evaporator cavity filled with coolant is connected to the heat exchanger.

Behind Last year heat pumps have occupied their niche in the Russian climate market, among other popular technologies. Discussion of the advantages and disadvantages of heat pump installations (HPU) took place both on the pages of the industry press and at thematic conferences and round tables. About heat pumps in recent times a lot of information appeared - both in the Russian-language Internet and in specialized media. However, there are still very few publications on integrated heat pump systems. The purpose of this article is to somewhat fill this gap, to summarize some of the questions that arise in specialists when they first get acquainted with ring heat transfer systems, and to briefly answer them.

So, it is known about heat pumps that this is climatic equipment capable of utilizing the heat of the environment, using a compressor to raise the temperature of the coolant to the desired level and transfer this heat to where it is needed.

It is almost always possible to extract heat from the environment. After all, "cold water" is a subjective concept, based on our feelings. Even the coldest river water contains some heat. But it is known that heat passes only from a hotter body to a colder one. Heat can be forcibly directed from a cold body to a warm one, then the cold body will cool down even more, and the warm one will heat up. Using a heat pump that "pumps out" heat from the air, river water or earth, lowering their temperature even more, it is possible to heat the building. In the classical case, it is considered that, spending 1 kW of electricity on operation, HPI can produce from 3 to 6 kW of thermal energy. In practice, this means that the power of two or three household light bulbs in winter can heat a medium-sized living room. In the summer, working in reverse mode, the heat pump can cool the air in the rooms of the building. The heat from the building will be removed by being absorbed by the atmosphere, river or earth.

Currently, there is a huge variety of heat pump installations, which allows them to be widely used in industry, agriculture, in housing and communal services. As an example of the use of HPP, at the end of the article we will consider two projects - one of them is a project of a large-scale ring system implemented in the Krasnodar Territory, the second is a small-scale construction facility in the Moscow region.

What are heat pumps?

Heat pumps come in a variety of heat outputs ranging from a few kilowatts to hundreds of megawatts. They can work with various heat sources in different aggregate states. In this regard, they can be divided into the following types: water-water, water-air, air-water, air-air. Heat pumps are produced, designed to work with sources of low-grade heat of various temperatures, up to negative. They can be used as a receiver of high potential heat requiring different temperatures, even above 1000C. Depending on this, heat pumps can be divided into low temperature, medium temperature and high temperature.

Heat pumps also differ in terms of technical device. In this regard, two directions can be distinguished: vapor compression and absorption HPP. Heat pumps for their work can use other types of energy, in addition to electricity, for example, they can run on various types fuel.

Various combinations of types of low-potential heat sources and high-grade heat receivers provide a wide variety of types of heat pumps. Here are some examples:

• HPP using heat ground water for heating;
• HPP, using the heat of a natural reservoir for hot water supply;
• HPI-air conditioner using sea water as a source and receiver of heat;
• HPI-air conditioner using outside air as a source and receiver of heat;
• TNU for water heating a swimming pool that uses the heat of the outside air;
• HPP, utilizing wastewater heat in the heat supply system;
• HPP, utilizing the heat of engineering and technical equipment in the heat supply system;
• HPP for cooling milk and at the same time heating water for hot water supply on dairy farms;
• HPP for heat recovery from technological processes in the primary heating of the supply air.

A wide variety of heat pump equipment is mass-produced, but heat pumps can also be manufactured according to special projects. There are experimental installations, pilot industrial samples, as well as many theoretical developments.

If the facility provides for the use of several heat pumps, which will be designed to produce both heat and cold, their efficiency will increase many times if they are combined into a single system. These are the so-called ring heat pump systems (KHNS). Such systems are expedient to use on average and large objects.

Ring air conditioning systems

These systems are based on water-air heat pumps that perform the functions of air conditioning in the premises. In the room where air conditioning is provided (or near it), a heat pump is installed, the power of which is selected in accordance with the parameters of the room, its purpose, the characteristics of the required supply and exhaust ventilation, the possible number of people present, the equipment installed in it and other criteria. All HPPs are reversible, that is, they are designed for both cooling and heating air. All of them are connected by a common water circuit - pipes in which water circulates. Water is both a source and a receiver of heat for all HPI. The temperature in the circuit can vary from 18 to 320C. Between heat pumps that heat the air and those that cool it, heat is exchanged through a water circuit. Depending on the characteristics of the premises, as well as on the time of year and time of day - in different rooms either heating or cooling may be required. With simultaneous operation in the same building of HPI producing heat and cold, heat is transferred from rooms where it is in excess to rooms where it is not enough. Thus, there is an exchange of heat between the zones, united in a single ring.

In addition to HPP performing the function of air conditioning, HPP for other purposes may also be included in the HPP. If there are sufficient heat requirements at the facility, waste heat can be efficiently utilized through the ring system using HPI. For example, in the presence of an intensive wastewater flow, it makes sense to install a water-to-water HPI, which will allow waste heat to be utilized by means of a HPS. Such a heat pump will be able to extract heat from wastewater, transfer it using a ring circuit, and then use it to heat rooms.

Air removed from the building exhaust ventilation, also contains a large amount of heat. In the absence of a large amount of impurities in the exhaust air that impede the operation of the HPI, it is possible to utilize the heat of the exhaust air by installing an air-to-water HPI. Through CHP this heat can be used by all consumers in the building, which is difficult to achieve using traditional regenerators and recuperators. In addition, the recycling process in this case can be more efficient, since it does not depend on the temperature of the outside air taken in by the supply ventilation, and on the set temperature for heating the air injected into the premises.

In addition, when operating reversible heat pumps in both wastewater and exhaust ventilation, they can be used to remove excess heat from the water circuit during the warm season, and thereby reduce the required capacity of the cooling tower.

In the warm season, with the help of heat pumps, excess heat in the water circuit is utilized through consumers available at the facility. For example, a water-to-water HPI can be connected to the ring system, transferring excess heat to the hot water supply system (DHW). In a facility with little need for hot water, this heat pump may be enough to fully satisfy them.

If the facility has one or more swimming pools, for example, in health facilities, rest homes, entertainment complexes and hotels, the pool water can also be heated using a water-to-water heat pump by connecting it to the KTN.

Combination of ring systems with other systems

The ventilation system in buildings using an annular heat pump system must be developed taking into account the peculiarities of the operation of HPPs that condition air. It is obligatory to recirculate air in the volume that is necessary for the stable operation of these heat pumps, maintaining the set temperature in the room and efficient heat recovery (the exception is those cases where recirculation is undesirable, for example, swimming pool halls, local kitchen hoods). There are some other features in the development of ventilation with CTNS.

However, at the same time, ring system more simple systems ventilation than other types of air conditioning. Heat pumps carry out air conditioning directly on site, in the room itself, which eliminates the need to transport the finished air through long, heat-insulated air ducts, as happens, for example, with central air conditioning.

The ring system can fully take over the functions of heating, but joint use with the heating system is not excluded. In this case, a less powerful and technically simpler heating system is used. Such a bivalent system is more suitable for northern latitudes where necessary more heat for heating, and it will have to be supplied in larger quantities from a high-potential source. If separate air conditioning and heating systems are installed in the building, then these systems often literally interfere with each other, especially during transitional periods. The use of a ring system in conjunction with a heating system does not give rise to such problems, since its operation is completely dependent on the actual state of the microclimate in each individual zone.

At enterprises, ring heat pump systems can be involved in heating or cooling water or air for technological purposes, and these processes will be included in the balance of the general heat supply of the enterprise.

Speaking about traditional heat supply systems, it is difficult to agree with their limited efficiency. Heat is partially used, quickly dissipated into the atmosphere (during heating and ventilation operation), removed with wastewater (through hot water supply, technological processes) and in other ways. It is also good if, to ensure some efficiency, air-to-air heat exchangers are installed in the ventilation system, or water-to-water type for heat recovery, for example, refrigeration units, or some other local heat recovery device. KTNS, on the other hand, solves this problem in a complex manner, in many cases making it possible to make heat recovery more efficient.

Automated control of ring systems

To the dismay of many manufacturers of expensive automation systems, heat pump systems do not require sophisticated facilities. automated control. All regulation here is reduced only to maintaining a certain value of the water temperature in the circuit. In order to prevent water cooling below the set limit, it is necessary to turn on the additional heater in time. And vice versa, in order not to exceed the upper limit, it is necessary to turn on the cooling tower in a timely manner. Automatic management of this simple process can be implemented using several thermostats. Since the water temperature in the HPNS circuit can vary over a fairly wide range (usually from 18 to 320C), there is also no need to use precise control valves.

As for the process of heat transfer from the heat pump to the consumer, it is controlled by automation built into each heat pump. For example, HPI for air conditioning have a temperature sensor (thermostat) installed directly in the room. This ordinary thermostat is quite enough to control the operation of the HP.

The heat pump fully provides the necessary temperature parameters air in the premises, which makes it possible to refuse control dampers in the ventilation system and control valves in the heating system (with a bivalent system). All these circumstances contribute to cost reduction and reliability increase. engineering systems generally.

At large facilities where the ring system includes a large number of heat pumps and where various types of HPPs are installed (for air conditioning, heat recovery and for ensuring technological processes), it often makes sense to implement a more complex automated control system that allows optimizing the operation of the entire system.

The operation of an annular heat pump system is affected by the following factors:

• Firstly, the temperature of the water in the circuit. The heat conversion coefficient (COP) depends on it, that is, the ratio of the amount of heat supplied to the consumer to the amount of energy consumed by the heat pump;
• secondly, the outside air temperature;
• thirdly, the operating parameters of the cooling tower. For the same amount of heat removed at different conditions different amounts of energy consumed by the cooling tower can be expended. This, in turn, also depends on the temperature of the outside air, its humidity, the presence of wind and other conditions;
• fourthly, on the number of heat pumps currently working in the system. Here, the total power of the HPI, which take heat from the water circuit, is important in comparison with the power of all HPI, which transfer heat to the circuit, that is, the amount of heat entering the circuit or removed from it.

Good for the kids, good for the budget

Let's move on to the description of projects using ring heat pump systems.

The first project is the reconstruction of a conventional secondary school in the south of Russia. Last summer, the administration Krasnodar Territory implemented this project in Ust-Labinsk (city school No. 2). During the reconstruction, the highest standards were maintained in ensuring sanitary requirements and a comfortable stay for children at school. In particular, a full-fledged climate system was installed in the building, providing zone-by-zone control over temperature, fresh air inflow and humidity.

When implementing this project, engineers, firstly, wanted to ensure the proper level of comfort, individual control in each class. Secondly, it was assumed that the ring system would significantly reduce the cost of heating the school and solve the problem of low water temperature in the heating plant on the school site. The system consists of more than fifty heat pumps manufactured by Climatemaster (USA) and a cooling tower. It receives additional heat from the heating plant of the city. The climate system is under automated control and is able to independently maintain the most comfortable for a person and at the same time economical modes of operation.

The operation of the described system in the winter months gave the following results:

• before modernization (before the installation of heat pumps), the monthly heating costs for 2,500 m2 were 18,440 rubles;
• after the modernization of the building, the heated area increased to 3000 m2, and the monthly heating costs decreased to 9800 rubles.

Thus, the use of heat pumps made it possible to more than halve the cost of heating the building, the heated area of ​​which increased by almost 20%.

Autonomous heat

The problems of cottage construction in the Moscow region today are due to the fact that the infrastructure ( Electricity of the net, water pipes), often prevents the growth of new settlements. Existing transformer substations unable to cope with increased workloads. Constant interruptions in the supply of electricity (accidents at old substations, breaks in dilapidated wires) force consumers to look for ways of autonomous power supply.

In the described project, the engineers were faced with the task of providing a multi-room two-story cottage with an attic with heat and electricity. The total heated area of ​​the house was 200 m2. From the failed communications - artesian water and electricity.

Since the requirement of energy efficiency was put at the forefront, it was decided to install solar panels. 3.5 kW solar photovoltaic modules were purchased and installed right on the site behind the house. According to the calculations of the engineers, this should have been enough to recharge the batteries, which, in turn, would uninterruptedly feed the house and the heating system. The total cost of the system was about $27,000. Given that the received source free electricity, and this article will be deleted from family budget, it turns out that the cost of installing a solar battery will pay off in less than 10 years. And if we consider that otherwise we would have to build a substation or live with constant power outages, then the costs can already be considered paid off.

For heating, it was decided to use a geothermal heat pump system. An American water-to-water heat pump was purchased. This type of heat pump produces hot water using heat exchangers, which can be used for hot water supply and heating with radiator batteries. The circuit itself, supplying low-grade heat to the heat pump, was laid directly on the site adjacent to the cottage, at a depth of 2 m. The circuit is polyethylene pipe, with a diameter of 32 mm and a length of 800 m. Installation of a heat pump with installation, supply of equipment and components cost 10,000 US dollars.

Thus, having spent about 40,000 US dollars on organizing his own autonomous energy system, the owner of the cottage excluded the cost of heat supply from his budget and provided reliable autonomous heating.

Possibilities of application of ring systems

From the foregoing, it follows that the possibilities of using an annular heat pump system are unusually wide. They can be used on a wide variety of objects. These are administrative public buildings, medical and health institutions, rest houses, entertainment and sports complexes, various industrial enterprises. The systems are so flexible that they can be used in the most different occasions and in a very large number of options.

When developing such a system, first of all, it is necessary to assess the needs for heat and cold of the object being designed, to study all possible heat sources inside the building and all prospective heat receivers, to determine heat gains and heat losses. The most suitable heat sources can be used in the ring system if this heat is required. The total capacity of the heat recovery heat pumps should not be needlessly redundant. Under certain conditions, the most profitable option may be the installation of HPPs that use the external environment as a source and receiver of heat. The system must be balanced in terms of heat, but this does not mean at all that the total capacities of heat sources and consumers should be equal, they can differ, since their ratio can change significantly when the operating conditions of the system change.

Thus, the ring heat pump system performs the functions of both heating and air conditioning, and efficient heat recovery. The use of one system instead of several is always more profitable in terms of capital and operating costs.

Article provided by the company "AEROCLIMATE"

One of the most popular types of equipment on the market climate technology Russia and the CIS are heat pumps. They are preferred by many buyers who want to create effective system cooling and heating their homes and offices, but very few people understand how this technique works and often do not even know in what situations it is best to use it. In the meantime, there are several basic questions regarding the operation of heat pump installations, and it will not be difficult even for beginners to understand them.

What are heat pumps?

This category of equipment includes equipment that is able to utilize the heat received from the environment, using a compressor to increase the temperature of the coolant to a predetermined level and then transfer heat to a certain room. At the same time, heat pumps can extract heat from any media, literally "pumping" it out of the environment. Thus, the pumps are able to work with:

• cold, frosty air
• cold water
• earth.

By lowering the temperature of the coolant, such climate control equipment can effectively heat any building.

Specifications of the pump

In general, a heat pump unit, unlike other types of climate control equipment, consumes a minimum amount of electricity in the course of its work. On average, she needs to spend only 1 kW of energy, and this will be enough to produce 3-6 kW of heat. In other words, using the power of 2-3 conventional light bulbs in winter, you can effectively heat a medium-sized living room. In summer, the same power can be used to cool the room: in this case, the heat pump will absorb heat from the air in the room and discharge it into the atmosphere, into the ground or into the water, creating coolness in any room.

What are heat pumps?

There is a wide range of equipment on the market that can be used in various fields , including:

• Living spaces,
• agricultural enterprises,
• industrial enterprises,
• Department of Housing and Utilities.

Of course heat pump installations for different rooms have different characteristics and may even vary in size. The pumps have different thermal power(from a few kW to hundreds of megaW), as well as can work with different sources heat, regardless of their state of aggregation (solid, liquid or gaseous). Given the characteristics of the operation of such equipment, Heat pump installations are divided into the following types:

• water-water,
• air-water,
• water-air,
• air-to-air,
• ground-water,
• soil-air.

There are also heat pumps on the market that are specially designed to work with low-grade heat. The sources of such heat can even have a negative temperature, and in this case the heat pump serves as a receiver of high-potential heat, which takes even a very high temperature (more than 1 thousand degrees). Generally, according to the temperature at which the installation works, it is divided into:

• low temperature
• medium temperature
• high temperature.

Another parameter by which heat pump installations are distinguished is related to their technical device. According to this indicator, the equipment is divided into such types as:

• absorption,
• vapor compression.

As a rule, all heat pumps, regardless of their type, work with electrical energy, but in certain cases they can be switched to other types of energy using a variety of fuels. According to the specifics of this fuel and the operation of the equipment itself, heat pump installations are divided into the following types:

• a heating device that uses heat from groundwater,
• pump for hot water supply, working with heat obtained from natural reservoirs,
• sea ​​water air conditioner
• air conditioning unit using outside air,
• pump for heating water in swimming pools, powered by outdoor air,
• a heat pump unit for a heat supply system that utilizes the heat generated by engineering and technical equipment,
• a device that runs on milk - it serves to cool milk and subsequent hot water supply and is used on dairy farms,
• installation for utilization of heat obtained as a result of technological processes - serves to heat the supply air.

There are also other types of such equipment. At the same time, as a rule, heat pumps of any type are mass-produced, however, individual unique units can be manufactured according to exclusive projects. You can also find experimental heat pumps, many drawings that have not yet been implemented, and pilot models of such equipment, which can also be used in any special room.

All heat pump installations can be combined into a single system. This is necessary if several units of such equipment are operating at one facility, producing both heat and cold. Combining them together will only increase their effectiveness, and at medium or large facilities it is recommended to immediately plan the creation of such complex equipment.

What are Ring Air Conditioning Systems?

Such a system is completed on the basis of heat pumps of various types, although an air-to-air installation is usually used for these purposes. The heat pump in this case serves as an air conditioner: it is installed directly in the refrigerated room, and the power of such equipment is selected in accordance with a number of parameters. Among them:

• the characteristics of the room itself,
• purpose of the premises
• the number of people who are in it,
• equipment that is installed or will be installed in it.

Air conditioning units are always reversible - they both cool and generate heat at the same time. They are connected by a common water circuit - a pipeline through which water circulates, being both a source and a receiver of heat. As a result, the temperature inside the circuit can fluctuate within 18-32 degrees, and it is through it that heat is exchanged between the heat pumps that heat the air and between the equipment that cools it. If you want to create a climate with different characteristics in different rooms, heat pumps simply transfer heat from rooms that have an excess of it to rooms where there is not enough heat. This makes it possible to create an annular heat exchange between different zones, and such a system is very efficient and economical.

At the same time, ring systems can include not only air conditioning equipment, but also other installations. In particular, such devices can utilize waste heat. This is required where there are rather large heat requirements, for example:

• at facilities where there is an intense flow of wastewater: a water-to-water heat pump installation can easily utilize the heat emanating from it and direct it using a ring circuit for space heating;
• in facilities with exhaust ventilation that removes air from the building(provided that there are not too many impurities in the air that would make it difficult for the heat pump to work): in this case, an air-to-water installation will be needed, which will recover the heat from the "unnecessary" air and transfer it to space heating or water heating ,
• at facilities where there is both wastewater and exhaust ventilation- on them, ring systems can be used to remove excess heat from the water circuit (usually this is done only in the warm season), which will reduce the capacity of the cooling tower.

In any situation, the ring system allows you to use heat repeatedly and send it to the needs of absolutely all consumers located in the building, and this is precisely its uniqueness, because traditional recuperators and regenerators are not capable of this.. Moreover, such a system utilizes heat more efficiently, since its operation does not depend in any way on the temperature of the air that is taken in by the supply ventilation, and on the set temperature of the air that enters the premises.

In summer, the ring system, operating on the basis of a water-to-water heat pump unit, is able to effectively remove excess heat from the water circuit, utilizing it through consumers: excess heat is supplied to the hot water supply system, and it is usually enough to satisfy all the needs of the inhabitants of any room in hot water. Such a system will be especially effective at facilities with several swimming pools (holiday homes, hotels, health centers) - with its help, it will be possible to heat the water in the pools very quickly and without extra costs.

Is the ring system compatible with other equipment systems?

Of course, yes, and above all it must be coordinated with the ventilation system. The latter, in particular, must be developed taking into account all the characteristics of the heat pump equipment that will condition the air. In particular, ventilation system it is imperative to ensure air recirculation in the volumes necessary for the stable operation of the pump, efficient heat recovery and maintaining the set temperature in the room. This rule should be followed in all facilities, with the exception of some where recirculation is undesirable, such as swimming pools or kitchens.

At the same time, the advantage of matching the ring system with the ventilation system is that the latter in this case can be built according to a simpler scheme, which will cost the consumer less. In this case, the heat pump will cool the air directly where it is needed. This will save the consumer from the need to transport it through long heat-insulated air ducts and will favorably distinguish such a system from the now common centralized air conditioning.

Besides, ring systems can be coordinated with heating systems, and sometimes even completely take over their functions. In such situations, a heating system based on a heat pump becomes less powerful and simpler in terms of its equipment. This makes it particularly effective in cold climates where more heat is required for heating, obtained from high-potential sources. Furthermore, the ring system can seriously optimize the operation of all equipment in the room. Separate air conditioning and heating systems can seriously interfere with each other, especially when both are not required. The ring system completely excludes such a situation, since it always works effectively, based on the actual state of the microclimate created in each particular room. At the same time, at the enterprise, such equipment can cool and heat not only air, but also water, and this process will not require extra energy costs - it will be included in the balance of the entire heat supply as a whole.

And, of course, in any of these situations, the ring system will demonstrate excellent economy. In traditional systems, heat is used only partially and quickly escapes into the atmosphere if heating works in parallel with ventilation, however, the ring system solves this problem in a complex way, making heat recovery more efficient and significantly reducing its losses.

How to manage heat pump systems?

As a rule, this equipment does not require the installation of expensive automated controls, and this is another "article" to save on it. Convenient automation here is extremely simple and comes down only to maintaining the set temperature of the water in the circuit. To do this, the system simply turns on an additional heater in time so that the water does not cool more than it should, or it activates the cooling tower so that it does not heat up more than necessary. And this is usually enough to maintain an ideal climate.

Implement automatic control in this situation is possible with just a few thermostats. Moreover, this does not even require precise control valves! The temperature of the water in the loop of the ring system can vary over a wide range without requiring any additional funds for this.

Besides, a separate automation system also regulates the process of heat transfer by the heat pump to the consumer. It is built into the equipment itself, and one of the main elements of the system can be considered a thermostat (temperature sensor), which is installed directly in the room. It alone is enough to fully manage the operation of the heat pump installation. At the same time, the pump itself is able to provide all the necessary characteristics of the air temperature in the room without installing control dampers in the ventilation system, and control valves in the heating system. This allows you to further reduce the cost of the ring system and increase the reliability of all engineering communications buildings in general.

Generally a complex system automated control may be needed only in large facilities where many heat pumps are installed various types designed for air conditioning, technological processes and heat recovery. And in such situations, the installation of this system makes sense, because it allows you to optimize the operation of each piece of equipment. However, when installing it, it should be borne in mind that the operation of the ring system is influenced by a number of factors that even automation must “reckon with”. Among them:

• temperature of the water in the circuit, - it affects the heat conversion coefficient (the ratio of the amount of heat supplied to the consumer to the amount of energy consumed by the heat pump);
• outside air temperature;
• cooling tower operating parameters- it can expend a different amount of energy for the same amount of heat, and this depends on external conditions, including air temperature, wind and other factors;
• the number of heat pumps that operate in the system, as well as their total capacity(the ratio of the power of the equipment that takes heat from the water circuit and the power of the installations that give it to the circuit).

Are there successful examples of using ring systems?

There are quite a few such examples, but the following two can be considered “textbooks”.

The first is the reconstruction of secondary school No. 2 in Ust-Labinsk. In this building, all the strictest sanitary requirements have been met in order to achieve maximum comfort for the children who will study in this institution. In accordance with these requirements, a special climate system was installed there, which is able to seasonally control temperature, humidity and fresh air. At the same time, the engineers did everything possible to ensure that each class had individual control over the microclimate, and only the ring system could cope with providing such control. She allowed:

• significantly reduce the cost of heating the entire building,
• solve the problem of cold water in the heating plant located on the school site.

The system was assembled from more than 50 Climatemaster heat pumps (USA) and one cooling tower. It receives additional heat from the heating plant, and it is controlled by automation, which independently maintains comfortable conditions for teaching children and at the same time works as economically as possible. It is thanks to her that the operation of the ring system, even in the most severe winter time, made it possible to reduce monthly heating costs to 9.8 thousand rubles: before the system was upgraded, the school spent 18 thousand 440 rubles every month on heating 2.5 thousand square meters. m. And this despite the fact that after the modernization, the heated area of ​​the school increased further, which amounted to 3 thousand square meters. m.

The second project was implemented in cottage villages near Moscow. The problems of building such settlements were often due to the fact that the infrastructure in these territories did not allow the construction of new houses, since neither water pipes, nor electrical networks, nor transformer substations simply could not cope with the increased loads. At the same time, power outages, breaks in old wires, various accidents constantly occurred at old substations, so in the villages located in such territories, it was necessary to immediately take care of autonomous power supply.

Accordingly, the engineers needed to create a project that would provide a two-story cottage with several rooms with electricity and heat. The standard area of ​​such a house was 200 square meters. m, and only electricity and artesian water were connected to it, there were no other communications.

The engineers took the first step towards energy efficiency - solar panels were installed in the cottage, and photovoltaic modules were installed behind the house, also powered by solar energy and having a capacity of 3.5 kW. This power was enough to feed the batteries, which subsequently powered the house itself and its heating system. Accordingly, electricity for a family living in such a cottage was free, which means that the cost of it could be deleted from the family budget. As a result, the cost of installing batteries should pay off in less than 10 years, and after that no funds will need to be allocated.

For heating the cottage, a geothermal heat pump installation based on a water-to-water pump was used. It was designed not only for space heating with radiator batteries, but also for the production of hot water. A circuit that supplies low-grade heat to the pump - that is, an ordinary polyethylene pipe 800 m long and 32 mm in diameter - was laid on the site itself (at a depth of 2 meters). The installation of such a system (electricity + heating) was spent 40 thousand dollars, and given that in the future the owner will not have to spend money on payment utilities supplied centrally, he only benefited from this.

Where can ring systems be used?

In general, all examples demonstrate that such heat pump installations can be mounted on a variety of objects. Among the main ones are:

• administrative buildings,
• medical and health institutions,
• public buildings,
• educational institutions,
• holiday homes and hotels,
• sport complexes,
• industrial enterprises,
• entertainment establishments.

At the same time, in any case, the flexible ring system can be easily adjusted to the needs of a particular room and mounted in the greatest variety of options.

To install it, engineers will need to take into account a number of nuances:

• needs for cold and heat at a particular facility,
• the number of people who are inside the premises,
• possible sources of heat in the building,
• possible heat sinks,
• features of heat loss and heat gain.

After that, the most best sources heat will be used in the system itself, while the total capacity of the heat pumps must be adjusted so as not to be excessive.

On the whole, ideal option for any object, experts consider the installation of heat pump equipment that uses the environment both as a heat source and as its receiver. At the same time, the entire system should be balanced in terms of heat, regardless of the capacities of heat sources and receivers - they can be different, because their ratio changes when the operating conditions of the system change. However, they must be consistent with each other.

If these parameters are taken into account correctly, the ring system will effectively work both for heating and cooling, utilizing all the "excess" heat. And the use of one such system instead of several will not only create an ideal indoor climate, but will also be very efficient and profitable in terms of both capital and operating costs.

The main difference between a heat pump and all other heat sources is its exceptional ability to use renewable low-temperature environmental energy for heating and water heating. About 80% of the output power, the heat pump actually "pumps out" from the environment, using the scattered energy of the Sun.

How a heat pump works

The refrigerator, everyone knows, transfers heat from the internal chamber to the radiator and we use the cold inside the refrigerator. A heat pump is a refrigerator "in reverse". It carries the dissipated heat from the environment into our home.

The coolant (which is water or brine), having taken a few degrees from the environment, passes through the heat pump heat exchanger, called the evaporator, and gives off the heat collected from the environment to the internal circuit of the heat pump. The internal circuit of the heat pump is filled with refrigerant, which, having a very low boiling point, passing through the evaporator, turns from a liquid state into a gaseous state. This occurs at low pressure and a temperature of 5°C. From the evaporator, the gaseous refrigerant enters the compressor, where it is compressed to high pressure and high temperature. Next, the hot gas enters the second heat exchanger - the condenser, where heat is exchanged between the hot gas and the coolant from the return pipe of the house heating system. The refrigerant gives off its heat to the heating system, cools down and goes back to liquid state, and the heated coolant of the heating system enters the heating devices.

Advantages of a heat pump

• - Economy. Low power consumption is achieved through high efficiency(from 300% to 800%) and allows you to get 3-8 kW of thermal energy per 1 kW of actually consumed energy, or up to 2.5 kW of output cooling power.
• - Environmental friendliness. Environmentally friendly method of heating and air conditioning for both the environment and the people in the room. The use of heat pumps is the saving of non-renewable energy resources and environmental protection, including by reducing CO2 emissions into the atmosphere. The heat pumps of the plant, carrying out a reverse thermodynamic cycle on a low-boiling working substance, draw renewable low-potential thermal energy from the environment, increase its potential to the level required for heat supply, spending 1.2-2.3 times less primary energy than with direct fuel combustion.
• - Security. There is no open flame, no soot, no exhaust, no smell of diesel fuel, no gas leakage, no fuel oil spill. There are no fire hazardous storage facilities for fuel.
• - Reliability. Minimum moving parts. High resource of work. Independence from the supply of furnace material and its quality. Power outage protection. Virtually maintenance free. The service life of a heat pump is 15-25 years.
• - Comfort. The heat pump operates silently (no louder than a refrigerator), and weather-dependent automation and multi-zone climate control create comfort and coziness in the premises.
• - Flexibility. The heat pump is compatible with any circulation system heating, and modern design allows you to install it in any room.
• - Versatility in relation to the type of energy used (electric or thermal).
• - Wide power range (from fractions to tens of thousands of kW).

Applications of heat pumps

The scope of heat pumps is truly limitless. All the above advantages of this equipment make it easy to solve the issues of heat supply to the urban complex and objects located far from communications, whether it is a farm, a cottage settlement or a gas station on the highway. In general, the heat pump is universal and applicable both in civil and industrial, and in private construction.

Today, heat pumps are widely used all over the world. The number of heat pumps operating in the US, Japan and Europe is in the tens of millions.

The production of heat pumps in each country is primarily focused on meeting the needs of the domestic market. In the United States and Japan, air-to-air heat pump units (HPUs) for heating and summer air conditioning have received the greatest use. In Europe - HPI of the "water-to-water" and "water-to-air" classes. In the US, more than sixty firms are engaged in research and production of heat pumps. In Japan, the annual production of HPP exceeds 500,000 units. In Germany, more than 5,000 installations are commissioned annually. In the Scandinavian countries, mainly large HPPs are operated. In Sweden, by 2000, more than 110 thousand heat pump stations (HPS) were in operation, 100 of which had a capacity of about 100 MW and more. The most powerful HPS (320 MW) operates in Stockholm.

The popularity of heat pumps in Western Europe, USA and countries South-East Asia largely due to mild climatic conditions in these regions (with a plus average temperature in winter), high fuel prices and the availability of targeted government programs to support this area of ​​the climate market.

The situation with heat pumps in our country is fundamentally different, and there are reasons for that. First, features Russian climate with low temperatures in winter place special demands on the parameters of heat pumps and their installation conditions. In particular, with an increase in the power of the heat pump, the problem of heat removal arises, since the heat transfer of the media (water body, soil, air) is limited and rather small.

In addition, gas prices are artificially low in Russia, so there is no need to talk about tangible economic benefits from the use of this kind of equipment, especially in the absence of a culture of consumption and saving electricity. We do not have state support for the energy substitution program; there were and are no domestic manufacturers of heat pumps.

At the same time, Russia's needs for such equipment are huge, and the entire "line" of heat pumps with a capacity of 5, 10, 25, 100 and 1000 kW seems to be in demand. Yes, in middle lane In Russia, for heating a house with an area of ​​100 m2, it is necessary to have a thermal power of 5-10 kW, and a pump with a thermal power of 100 kW is sufficient for heating typical schools, hospitals and administrative buildings. Heat pumps with a capacity of 1000 kW are convenient for the tasks of recovering heat waste, using hot springs. According to experts, the cost of installing a heat pump in Russian conditions is estimated at about 300 US dollars per 1 kW of thermal power, with a payback period of equipment from two to four years, which primarily depends on fuel prices and climatic conditions of a particular region.

The commissioning of about 100,000 heat pumps with a total heat output of 2 GW will make it possible to supply heat to 10 million people with an average service life of a heat pump of 15 years. The volume of sales of such equipment can be more than half a billion dollars a year.