Heat pump installations (heat pumps) - alternative home heating. Heat pump installations

Having refrigerators and air conditioners in their home, few people know that the principle of operation of a heat pump is implemented in them.

About 80% of the power supplied by a heat pump comes from ambient heat in the form of scattered solar radiation. It is his pump that simply “pumps” from the street into the house. The operation of a heat pump is similar to the principle of operation of a refrigerator, only the direction of heat transfer is different.

Simply put…

To chill the bottle mineral water You put it in the refrigerator. The refrigerator must “take away” part of the thermal energy from the bottle and, according to the law of conservation of energy, move it somewhere, give it away. The refrigerator transfers heat to a radiator, usually located on its back wall. At the same time, the radiator heats up, giving off its heat to the room. In fact, it heats the room. This is especially noticeable in small mini-markets in the summer, with several refrigerators in the room.

We invite you to imagine. Suppose that we will constantly put warm objects in the refrigerator, and it will, by cooling them, heat the air in the room. Let's go to the "extremes" ... Let's place the refrigerator in the window opening with the open door of the "freezer" out. The refrigerator radiator will be in the room. During operation, the refrigerator will cool the air outside, transferring the "taken" heat into the room. This is how a heat pump works, taking dispersed heat from the environment and transferring it to the room.

Where does the pump get the heat?

The principle of operation of a heat pump is based on the "exploitation" of natural low-grade heat sources from the environment.

They may be:

• just outside air;
• heat of reservoirs (lakes, seas, rivers);
• ground heat, ground water(thermal and artesian).

How is a heat pump and a heating system with it arranged?

The heat pump is integrated into the heating system, which consists of 2 circuits + the third circuit - the system of the pump itself. A non-freezing coolant circulates along the external circuit, which takes heat from the surrounding space.

When it enters the heat pump, or rather its evaporator, the coolant gives off an average of 4 to 7 °C to the heat pump refrigerant. And its boiling point is -10 °C. As a result, the refrigerant boils, followed by a transition to a gaseous state. The coolant of the external circuit, already cooled, goes to the next “coil” through the system to set the temperature.

As part of the functional circuit of the heat pump "listed":

• evaporator;
• compressor (electric);
• capillary;
• capacitor;
• coolant;
• thermostatic control device.

The process looks like this!

The refrigerant "boiled" in the evaporator through the pipeline enters the compressor, powered by electricity. This "hard worker" compresses the gaseous refrigerant to high pressure, which, accordingly, leads to an increase in its temperature.

The now hot gas then enters another heat exchanger, which is called a condenser. Here, the heat of the refrigerant is transferred to the room air or heat carrier, which circulates through the internal circuit of the heating system.

The refrigerant cools down, at the same time turning into a liquid state. It then passes through a capillary pressure reducing valve, where it “loses” pressure and re-enters the evaporator.

The cycle is closed and ready to repeat!

Approximate calculation of the heating output of the installation

Within an hour, up to 2.5-3 m 3 of coolant flows through the external collector through the pump, which the earth is able to heat by ∆t = 5-7 °C.

To calculate the thermal power of such a circuit, use the formula:

Q \u003d (T_1 - T_2) * V_warm

V_heat - volumetric flow rate of the heat carrier per hour (m ^ 3 / h);

T_1 - T_2 - inlet and outlet temperature difference (°C) .

Varieties of heat pumps

According to the type of dissipated heat used, there are heat pumps:

• ground-water (use closed ground loops or deep geothermal probes and water system space heating);
• water-water (open wells are used for the intake and discharge of groundwater - the external circuit is not looped, internal system heating - water);
• water-air (use of external water circuits and air-type heating systems);
• (using the dissipated heat of external air masses, complete with the air heating system of the house).

Advantages and benefits of heat pumps

Economic efficiency. The principle of operation of a heat pump is based not on production, but on the transfer (transportation) of thermal energy, it can be argued that its efficiency is greater than one. What nonsense? - you will say. In the topic of heat pumps, the value appears - the coefficient of conversion (transformation) of heat (KPT). It is by this parameter that units of this type are compared with each other. His physical meaning- show the ratio of the amount of heat received to the amount of energy expended for this. For example, at KPT = 4.8, the electricity consumed by the pump in 1 kW will allow you to get 4.8 kW of heat with it free of charge, that is, a gift from nature.

Universal ubiquity of application. Even in the absence available lines power lines, the operation of the heat pump compressor can be provided by a diesel drive. And there is "natural" heat in any corner of the planet - the heat pump will not remain "hungry".

Ecological purity of use. There are no combustion products in the heat pump, and its low energy consumption "exploits" power plants less, indirectly reducing harmful emissions from them. The refrigerant used in heat pumps is ozone-friendly and does not contain chlorocarbons.

Bidirectional mode of operation. The heat pump can winter time heat the room, and in the summer - cool. The “heat” taken from the premises can be used efficiently, for example, to heat water in a pool or in a hot water supply system.

Operational safety. In the principle of operation of a heat pump, you will not consider dangerous processes. The absence of open flame and harmful emissions dangerous for humans, low temperature coolants make the heat pump a "harmless" but useful household appliance.

Full automation of the heating process.

Some nuances of operation

Efficient use of the principle of operation of a heat pump requires compliance with several conditions:

• the room that is heated must be well insulated (heat loss up to 100 W / m 2) - otherwise, taking heat from the street, you will heat the street for your own money;
• heat pumps are useful for low temperature systems heating. Under such criteria, underfloor heating systems (35-40 ° C) are excellent. The heat conversion coefficient significantly depends on the ratio of the temperatures of the inlet and outlet circuits.

Let's sum it up!

The essence of the principle of operation of a heat pump is not in production, but in the transfer of heat. This allows you to get a high coefficient (from 3 to 5) of thermal energy conversion. Simply put, each 1 kW of electricity used will “transfer” 3-5 kW of heat to the house. Is there anything else that needs to be said?

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 per winter period can be heated living room medium sizes. 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 the most different 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 sources of low-grade heat and receivers of high-grade heat give a wide variety of types of heat pumps. Here are some examples:

• HPP, using the heat of groundwater 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.

The air removed from the building by exhaust ventilation also contains a large amount of heat. In the absence of exhaust air a large number impurities that hinder the operation of the HPI, it is possible to utilize the heat of the removed 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 to more 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 HPS 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 of the 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 influenced 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, from the number of employees in this moment in the heat pump 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, inflow fresh air 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 (electrical networks, water pipes) often does not allow new settlements to grow. 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. Considering that a source of free electricity has been obtained, 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 costs 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 sport 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 sources of heat inside the building and all the proposed 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 HPP using 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"

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 heat pump units

K TN low power include small water heaters and window air conditioners including 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 pole heater) due to high unit costs. Only units designed primarily for refrigeration and heat generation are of practical importance due to their easy switching. 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. With the help of a four-way valve, they can switch to heat pump mode, 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 air conditioners high power intended for general industrial buildings is also performed with a switch to heat pump operation.

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. Waste heat exchanger depending on 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 of inclusion of APT in the technological processes of various industries, they can be divided into autonomous, independent of the scheme of the technological process, and built-in - with the combination of a part of the APT cycle with the technological 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 operating temperature and evaporation temperature. For small installations it is not possible to achieve high performance (WITH,< 1.5). In different countries, work is underway to improve small absorption heat pumps.

Heat pump units can be successfully and efficiently used in installations of joint winter heating and summer air conditioning; in installations for the joint production of cold and heat; in evaporating desalination and distillation plants; at hydroelectric power plants to use the heat of air and hydrogen, cooling electrical generators; at oil refineries and petrochemical plants when using the heat of hot oil products and hot water(t 60 H - 120 C) to obtain water vapor with a pressure of 10 kg / h2 and hot water with a temperature of 130 - 150 C.

The heat pump plant, which is used to heat the spa hall in winter, uses sea water as a source of heat. How will the thermal power of the installation change if it operates according to the internal reversible Carnot cycle at the same temperature differences in the evaporator and condenser. How will the heating coefficient change if external irreversibility is eliminated in the heat exchangers of a plant operating on the reverse Carnot cycle.

It is most expedient to use heat pump installations to satisfy a constant heat load in the presence of a constant source of low-grade heat and with a relatively small required heat rise, i.e. with a small & TTS-Ta value or with a TS / TB ratio close to one. Such conditions usually take place when satisfying, with the help of heat pump installations, a relatively constant industrial heat load of low potential or a load of hot water supply, in the presence of low-grade industrial heat waste with a temperature of 20–40 ° C and above. Under these conditions, heat pump installations, both in terms of energy indicators (fuel consumption) and in terms of reduced costs, are quite competitive with highly economical boiler installations.

Heat pump plant (Heat pump plant) consists of a heat pump, installation for the selection of heat from its source and other equipment.

A heat pump installation generally has a higher initial cost than boiler-based heating.

It is most expedient to use heat pump installations to satisfy a constant heat load in the presence of a constant source of low-grade heat and with a relatively small required heat rise, i.e. with a small & TTV-Ts value or with a TB / TV ratio close to one. Such conditions usually take place when satisfying, with the help of heat pump installations, a relatively constant industrial heat load of low potential or a load of hot water supply, in the presence of low-grade industrial heat waste with a temperature of 20–40 ° C and above. Under these conditions, heat pump installations, both in terms of energy indicators (fuel consumption) and in terms of reduced costs, are quite competitive with highly economical boiler installations.

Two-stage heat pump installations are sometimes used in heat supply systems that cover the heating load.

For the first time, a vapor compression ammonia heat pump plant was used for space heating in 1930. Since then, a large number of heat pumps have been built. There is reason to believe that in the future the use of heat pumps will be more widespread.

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 better 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 heat sources, 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, however, 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 different types, although an air-to-air unit is usually used for this purpose. 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 need to create a climate in different rooms with different characteristics, 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 sites where there are 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, separate system automation 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 different types of heat pumps are installed, 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, presence of 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 paying 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 best heat sources will be used in the system itself, and general power heat pumps must be configured so as not to be redundant.

On the whole, ideal option for any object, experts consider the installation of heat pump equipment that use environment both as a heat source and as a 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.