Solar energy and air energy double-heat-source heat pump system

Abstract

The utility model relates to a solar energy and air energy double-heat-source heat pump system, which comprises a heat pump system, an air source heat pump system and a solar energy heat pump system, the solar system is connected to the user side heat supply pipeline through a fifth heat collector water supply pipe, a seventh electric butterfly valve V7 is arranged on the fifth heat collector water supply pipe, the solar system is connected with the heat pump system through a fourth heat collector water supply pipe, and a sixth electric butterfly valve V6 is arranged on the fourth heat collector water supply pipe. The solar energy system and the air energy system can operate in parallel or in series by achieving coupled operation of the solar energy system and the air energy system, different working conditions are selected for operation according to the water outlet temperature of a solar heat collection plate, and the energy utilization efficiency of the system is maximized.

Description

Technical Field

[0001] The utility model relates to the technical field of heat pumps, in particular to a heat pump system with dual heat sources of solar energy and air energy. Background Art

[0002] At present, heat pumps, as a renewable energy utilization technology, are an effective way to use low-grade renewable energy for clean heating and cooling. They only consume a small amount of electricity to absorb low-temperature heat from the natural environment for heating. They are the best way to replace combustion heating and realize electricity-heat source conversion. They are an important technical support for achieving carbon peak and carbon neutrality.

[0003] Solar energy, an inexhaustible renewable energy source, is the most important energy source for future sustainable energy development. Solar energy can be utilized in two forms: solar thermal and photovoltaic. Solar thermal is primarily used in solar water heating systems or solar air conditioning. Solar thermal technology offers a range of advantages, including environmental friendliness and energy savings. However, it is significantly affected by day and night, and by the weather. It may not provide sufficient heat at night, on cloudy days, or in rainy or snowy conditions. Utility Model Content

[0004] Based on the above description, the utility model provides a dual-heat source heat pump system of solar energy and air energy to solve the problem in related technologies that solar energy is greatly affected by day and night and weather and cannot provide sufficient heat energy.

[0005] The technical solution of the utility model to solve the above technical problems is as follows: a solar energy and air energy dual heat source heat pump system, which includes: a heat pump system, which is connected to the user-side heating pipeline; a solar energy system, which is connected to the user-side heating pipeline through a collector water supply pipe five, and the collector water supply pipe five is provided with an electric butterfly valve seven V7, and the solar energy system is connected to the heat pump system through a collector water supply pipe four, and the collector water supply pipe four is provided with an electric butterfly valve six V6.

[0006] On the basis of the above technical solution, the present invention can also be improved as follows.

[0007] Furthermore, the solar energy system includes: a hot water storage tank, which is connected to the collector water supply pipe four through the collector water supply pipe three; a solar collector plate, which is connected to the hot water storage tank through the collector water supply pipe one, and the collector water supply pipe one is provided with a temperature sensor one T1; the heat pump system is connected to the solar collector plate through the collector return pipe one, and the collector return pipe one is provided with a temperature sensor five T5.

[0008] Furthermore, a temperature sensor four T4 is provided on the collector water supply pipe three, and a temperature sensor six T6 is provided on the user-side heating pipe.

[0009] Furthermore, the heat storage tank is provided with an upper water inlet and a lower water outlet, the upper water inlet is connected to the collector water supply pipe 1 through an upper water inlet pipe, and the upper water inlet pipe is provided with an electric butterfly valve 1 V1; the lower water outlet is connected to the collector water supply pipe 3 through a lower water outlet pipe, and the lower water outlet pipe is provided with an electric butterfly valve 4 V4; the collector water supply pipe 3 is connected to the collector return pipe 1 through a bypass pipe 2, and the bypass pipe 2 is provided with an electric butterfly valve 8 V8, and the collector return pipe 1 is provided with an electric butterfly valve 9 V9.

[0010] Furthermore, the heat storage tank is provided with an upper water outlet and a lower water inlet, the upper water outlet is connected to the collector water supply pipe three through an upper water outlet pipe, and the upper water outlet pipe is provided with an electric butterfly valve three V3; the lower water inlet is connected to the collector water supply pipe one through a lower water inlet pipe, and the lower water inlet pipe is provided with an electric butterfly valve two V2.

[0011] Furthermore, the collector water supply pipe 1 is connected to the collector return pipe 1 through a bypass pipe 1, and the bypass pipe 1 is provided with an electric butterfly valve 10 V10.

[0012] Furthermore, the heat pump system includes: a condenser, which is connected to the user-side heating pipe through a water-side loop inlet pipe, and a terminal valve 2 V22 is provided on the water-side loop inlet pipe; a water-cooled evaporator, which is connected to the condenser through a refrigerant low-pressure side liquid pipe 3, and a solenoid valve 2 V12 is provided on the refrigerant low-pressure side liquid pipe 3.

[0013] Furthermore, the heat pump system also includes an air-cooled evaporator, which is connected to the refrigerant low-pressure side liquid pipe 3 through the refrigerant low-pressure side liquid pipe 2, and the refrigerant low-pressure side liquid pipe 2 is provided with a solenoid valve 1 V11.

[0014] Furthermore, the water-cooled evaporator includes: a heat exchange coil E1, whose water inlet is connected to the collector water supply pipe four, and whose water outlet is connected to the collector return pipe one through the collector return pipe two; a heat exchange coil E2, whose water inlet and outlet are both connected to the user-side cooling pipe.

[0015] Furthermore, a terminal valve V23 is provided on the water inlet pipe of the heat exchange coil E2.

[0016] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:

[0017] When there is no solar heat source or the solar heat is insufficient, the heat pump system provides heat alone. When the solar heat source has sufficient heat, the solar system and the heat pump system operate in parallel. When the solar heat source has moderate heat, the solar system and the heat pump system operate in series. In this working condition, the hot water temperature of the solar system does not meet the set temperature requirement for heating. The heat pump system absorbs the heat from the low-temperature hot water of the solar system, heats it through the heat pump cycle, and obtains high-temperature hot water to meet the heating demand. By coupling the solar system with the air energy system, the two systems can be operated in parallel or in series. According to the outlet water temperature of the solar collector plate, different working conditions are selected to maximize the energy utilization efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the principle structure of a solar energy and air energy dual heat source heat pump system provided in an embodiment of the utility model.

[0019] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0020] 51. Heat pump system; 52. Solar energy system; 31. Heat exchanger; 501. User-side heating pipeline; 601. User-side cooling pipeline;

[0021] 1. Compressor; 2. Condenser; 3. Liquid storage tank; 4. Throttle valve; 5. Air-cooled evaporator; 6. Water-cooled evaporator; 401. Refrigerant high-pressure side gas pipe; 402. Refrigerant high-pressure side liquid pipe 1; 403. Refrigerant high-pressure side liquid pipe 3; 404. Refrigerant low-pressure side liquid pipe 1; 405. Refrigerant low-pressure side liquid pipe 2; 406. Refrigerant low-pressure side liquid pipe 3; 407. Refrigerant low-pressure side gas pipe 1; 408. Refrigerant low-pressure side gas pipe 2; 409. Refrigerant low-pressure side gas pipe 3;

[0022] 21. Solar collector panel; 22. Circulating water pump; 23. Check valve; 24. Heat storage tank; 201. Collector water supply pipe 1; 202. Collector water supply pipe 2; 203. Collector water supply pipe 3; 204. Collector water supply pipe 4; 205. Collector water supply pipe 5; 301. Collector return pipe 1; 302. Collector return pipe 2; 303. Collector return pipe 3;

[0023] 101. Bypass pipe 1; 102. Bypass pipe 2. DETAILED DESCRIPTION

[0024] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0025] The embodiment of the utility model provides a dual-heat source heat pump system of solar energy and air energy, which can solve the problem in the related art that solar energy is greatly affected by day and night and weather and cannot provide sufficient heat energy.

[0026] See also Figure 1 , a solar energy and air energy dual heat source heat pump system provided by an embodiment of the utility model includes a heat pump system 51, a solar energy system 52, a heat exchanger 31, a user-side heating pipe 501, a user-side cooling pipe 601, a terminal valve 1 V21, a terminal valve 2 V22, a terminal valve 3 V23 and a temperature sensor 1 T1, a temperature sensor 2 T2, a temperature sensor 3 T3, a temperature sensor 4 T4, a temperature sensor 5 T5 and a temperature sensor 6 T6.

[0027] In some embodiments, the heat pump system 51 may include: a compressor 1, a condenser 2, a liquid storage tank 3, a throttle valve 4, an air-cooled evaporator 5, a water-cooled evaporator 6, a solenoid valve one V11, a solenoid valve two V12, a refrigerant high-pressure side gas pipe 401, a refrigerant high-pressure side liquid pipe one 402, a refrigerant high-pressure side liquid pipe three 403, a refrigerant low-pressure side liquid pipe one 404, a refrigerant low-pressure side liquid pipe two 405, a refrigerant low-pressure side liquid pipe three 406, a refrigerant low-pressure side gas pipe one 407, a refrigerant low-pressure side gas pipe two 408, and a refrigerant low-pressure side gas pipe three 409.

[0028] Specifically, the compressor 1 is connected to the condenser 2 via a refrigerant high-pressure side gas pipe 401, the condenser 2 is connected to the liquid storage tank 3 via a refrigerant high-pressure side liquid pipe 1 402, the liquid storage tank 3 is connected to the throttle valve 4 via a refrigerant high-pressure side liquid pipe 3 403, the throttle valve 4 is connected to the air-cooled evaporator 5 via a refrigerant low-pressure side liquid pipe 1 404 and a refrigerant low-pressure side liquid pipe 2 405, the throttle valve 4 is connected to the water-cooled evaporator 6 via a refrigerant low-pressure side liquid pipe 1 404. , the refrigerant low-pressure side liquid pipe three 406 is connected, the air-cooled evaporator 5 is connected to the compressor 1 through the refrigerant low-pressure side gas pipe one 407 and the refrigerant low-pressure side gas pipe three 409, and the water-cooled evaporator 6 is connected to the compressor 1 through the refrigerant low-pressure side gas pipe two 408 and the refrigerant low-pressure side gas pipe three 409; the solenoid valve one V11 is arranged on the refrigerant low-pressure side liquid pipe two 405 pipeline, and the solenoid valve two V12 is arranged on the refrigerant low-pressure side liquid pipe three 406 pipeline.

[0029] In some embodiments, the solar energy system 52 may include: a solar collector panel 21, a circulating water pump 22, a check valve 23, a heat storage tank 24, an electric butterfly valve 1 V1, an electric butterfly valve 2 V2, an electric butterfly valve 3 V3, an electric butterfly valve 4 V4, an electric butterfly valve 6 V6, an electric butterfly valve 7 V7, an electric butterfly valve 8 V8, an electric butterfly valve 9 V9, an electric butterfly valve 10 V10, a collector water supply pipe 1 201, a collector water supply pipe 2 202, a collector water supply pipe 3 203, a collector water supply pipe 4 204, a collector water supply pipe 5 205, a collector return pipe 1 301, a collector return pipe 2 302, a collector return pipe 3 303, a bypass pipe 1 101, and a bypass pipe 2 102.

[0030] Specifically, the solar collector panel 21 is connected to the circulating water pump 22 through the collector water supply pipe 1 201, and the circulating water pump 22 is connected to the hot water tank 24 through the collector water supply pipe 2 202. The check valve 23 is arranged on the collector water supply pipe 2 202 at the outlet of the circulating water pump 22. The hot water tank 24 is connected to the primary side water pipe inlet of the heat exchanger 31 and the inlet of the heat exchange coil E1 of the water-cooled evaporator 6 through the collector water supply pipe 3 203, the collector water supply pipe 4 204, and the collector water supply pipe 5 205. The return water port of the solar collector panel 21 is connected to the primary side water outlet of the heat exchanger 31 and the water outlet of the heat exchange coil E1 of the water-cooled evaporator 6 through the collector return water pipe 1 301, the collector return water pipe 2 302, and the collector return water pipe 3 303.

[0031] In some embodiments, the heat storage tank 24 is provided with an upper water inlet, a water outlet and a lower water inlet and a water outlet, the upper water inlet and the lower water inlet are connected to the collector water supply pipe 202, and the upper water outlet and the lower water outlet are connected to the collector water supply pipe 3 203; the electric butterfly valve 1 V1 is provided on the upper water inlet pipe of the heat storage tank, the electric butterfly valve 2 V2 is provided on the lower water inlet pipe of the heat storage tank, the electric butterfly valve 3 V3 is provided on the upper water outlet pipe of the heat storage tank, and the electric butterfly valve 4 V4 is provided on the lower water outlet pipe of the heat storage tank.

[0032] In some embodiments, the bypass pipe 101 connects the collector water supply pipe 201 and the collector return pipe 301, and the bypass pipe 2 102 connects the collector water supply pipe 3 203 and the collector return pipe 301.

[0033] In some embodiments, the electric butterfly valve six V6 is set on the collector water supply pipe four 204, the electric butterfly valve seven V7 is set on the collector water supply pipe five 205, the electric butterfly valve six V8 is set on the bypass pipe two 102, the electric butterfly valve nine V9 is set on the solar collector water inlet pipe, and the electric butterfly valve ten V10 is set on the bypass pipe one 101.

[0034] In some embodiments, the secondary side of the heat exchanger 31 is connected to the heating pipeline 501 on the user side, the water-cooled evaporator 6E2 is connected to the cooling pipeline 601 on the user side, and the water-side loop of the condenser 2 is connected to the heating pipeline 501 on the user side.

[0035] In some embodiments, the end valve V21 is arranged on the water inlet pipe of the secondary side of the heat exchanger 31, the end valve V22 is arranged on the water inlet pipe of the water-side loop of the condenser 2, and the end valve V23 is arranged on the water inlet pipe of the water-cooled evaporator 6E2.

[0036] Among them, the temperature sensor T1 is arranged on the pipeline of the first collector water supply pipe 201 and is the outlet water temperature of the solar collector; the temperature sensor T2 is arranged at the upper part inside the heat storage water tank and is the high temperature at the upper part of the heat collection water tank; the temperature sensor T3 is arranged at the lower part inside the heat storage water tank and is the low temperature at the lower part of the heat collection water tank; the temperature sensor T4 is arranged on the pipeline of the third collector water supply pipe 203 and is the outlet water temperature of the heat collection water tank; the temperature sensor T5 is arranged on the pipeline of the first collector return pipe 301 and is the return water temperature of the solar collector; the temperature sensor T6 is arranged on the water supply pipeline of the heating pipeline 501 on the user side and is the set temperature of the heating system.

[0037] Table 1

[0038]

[0039] Note 6 is the set temperature of the heating system

[0040] Furthermore, referring to Table 1, it shows the system startup and shutdown and valve switch states in different operating modes of a solar and air energy dual-source heat pump system, realizing three operating modes: the heat pump system 51 supplies heat alone, the solar system 52 directly supplies heat, and the heat pump system 51 and the solar system 52 supply heat jointly.

[0041] When there is no solar heat source or the solar heat is insufficient (T1 - T5 < 0.5°C), the heat pump system 51 supplies heat alone, and the solar system 52 is in the heat storage working condition or is shut down. When the solar heat source is sufficient (T4 ≥ T6 + 2°C), the solar system 52 and the heat pump system 51 operate in parallel, and according to the heating demand on the user side, the solar system 52 is preferentially adopted, and the insufficient heat is supplemented by the heat pump system 51. When the solar heat source is moderate (T1 - T5 ≥ 0.5°C and T4 < T6 + 2°C), the solar system 52 and the heat pump system 51 operate in series. In this working condition, the hot water temperature of the solar system does not meet the heating set temperature requirement. The heat pump system absorbs the heat in the low-temperature hot water of the solar system and raises the temperature through the heat pump cycle to obtain high-temperature hot water to meet the heating demand.

[0042] Table 2

[0043]

[0044] Further, referring to Table 2, it is a valve conversion table for four working conditions of the solar energy system 52 in a solar and air energy dual-source heat pump system. Through valve switch control, the solar energy system realizes four working conditions: energy storage working condition 2A, combined supply working condition 2B, simultaneous supply and energy storage working condition 2C, and single supply of water tank working condition 2D.

[0045] Specifically, the conversion conditions for the four modes are as follows: energy storage working condition 2A - there is solar energy resource and no end heating demand; combined supply working condition 2B - insufficient solar energy resource and the energy storage water tank releases energy; simultaneous supply and energy storage working condition 2C - sufficient solar energy resource and the energy storage water tank stores energy; single supply of water tank working condition 2D - no solar energy resource. In the three working conditions of combined supply working condition 2B, simultaneous supply and energy storage working condition 2C, and single supply of water tank working condition 2D, the switch states of V6 and V7 need to be coordinated with the switch states of the heating mode selection in Table 3.

[0046] Table 3

[0047]

[0048] Further, referring to Table 3, it is a valve conversion table for three working conditions of the heat pump system 51 in a solar and air energy dual-source heat pump system. Through valve switch control, the heat pump system realizes three working conditions: solar energy heat source working condition 1A, air energy heat source working condition 1B, and refrigeration heat recovery working condition 1C. Among them, the solar energy heat source working condition 1A needs to operate in series with the solar energy system 52; the air energy heat source working condition 1B and the refrigeration heat recovery working condition 1C are the separate heating modes of the heat pump system.

[0049] Compared with the prior art, the technical solution of the present application has the following advantages:

[0050] 1. It realizes the coupled operation of the solar energy system and the air energy system, enabling the two systems to operate in parallel or in series. According to the outlet water temperature of the solar collector, different working conditions are selected to operate, maximizing the energy utilization efficiency of the system.

[0051] 2. Through the series operation of the solar energy system and the air energy system, when the outlet water temperature of the solar collector is low, i.e., T4 < T6 + 2°C (the outlet water temperature of the solar collector is less than the heating set temperature plus 2°C), the solar hot water system no longer meets the heating temperature requirements. The heat pump system absorbs the heat in the solar hot water system to prepare high-temperature hot water to meet the heating demand. The series operation realizes the improvement of the temperature quality of the hot water system, maximizes the absorption of solar energy heat, and ensures heating.

[0052] 3. The heat pump system adopts a double evaporator configuration. When there is no solar energy resource, the heat pump system absorbs ambient heat through the air-cooled evaporator to ensure the uninterrupted operation of the heating system and improve the heating guarantee.

[0053] 4. The water-cooled evaporator of the heat pump system adopts a dual-circuit design. Two heat exchange coils E1 and E2 are installed in the evaporator, which can realize heat recovery of cooling capacity. The heat pump can also provide cooling while heating, improve energy utilization efficiency, and realize multiple uses of one machine.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0055] It will be understood that spatial relational terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It will be understood that in addition to the orientations shown in the figures, spatial relational terms also include different orientations of the device in use and operation. For example, if the device in the drawings is turned over, the element or feature described as "under" or "beneath" or "beneath" the other elements will be oriented as "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include alternative orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0056] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediate element. In the following embodiments, "connection" should be understood as "electrical connection", "communication connection", etc., if the connected circuits, modules, units, etc. can transmit electrical signals or data to each other.

[0057] When used herein, the singular forms "a", "an", and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A solar energy and air energy dual heat source heat pump system, characterized in that: It includes: A heat pump system (51) connected to a user-side heating pipe (501); The solar energy system (52) is connected to the user-side heating pipeline (501) via a collector water supply pipe (5) (205), and an electric butterfly valve (7) (V7) is provided on the collector water supply pipe (5) (205). The solar energy system (52) is connected to the heat pump system (51) via a collector water supply pipe (4) (204), and an electric butterfly valve (6) (V6) is provided on the collector water supply pipe (4) (204).

2. The solar energy and air energy dual heat source heat pump system according to claim 1 is characterized in that: The solar energy system (52) comprises: a heat storage tank (24) connected to the heat collector water supply pipe 4 (204) via the heat collector water supply pipe 3 (203); The solar heat collecting plate (21) is connected to the heat storage tank (24) via a heat collector water supply pipe (201), the heat collector water supply pipe (201) is provided with a temperature sensor (T1), and the heat pump system (51) is connected to the solar heat collecting plate (21) via a heat collector return pipe (301), the heat collector return pipe (301) is provided with a temperature sensor (T5).

3. The solar energy and air energy dual heat source heat pump system according to claim 2 is characterized in that: The collector water supply pipe three (203) is provided with a temperature sensor four T4, and the user-side heating pipe (501) is provided with a temperature sensor six T6.

4. The solar energy and air energy dual heat source heat pump system according to claim 2, characterized in that: The heat storage tank (24) is provided with an upper water inlet and a lower water outlet, wherein the upper water inlet is connected to the collector water supply pipe (201) via an upper water inlet pipe, and an electric butterfly valve (V1) is provided on the upper water inlet pipe; the lower water outlet is connected to the collector water supply pipe (203) via a lower water outlet pipe, and an electric butterfly valve (V4) is provided on the lower water outlet pipe; The collector water supply pipe three (203) is connected to the collector return pipe one (301) through the bypass pipe two (102), the bypass pipe two (102) is provided with an electric butterfly valve eight V8, and the collector return pipe one (301) is provided with an electric butterfly valve nine V9.

5. The solar energy and air energy dual heat source heat pump system according to claim 4 is characterized in that: The heat storage tank (24) is provided with an upper water outlet and a lower water inlet, the upper water outlet is connected to the collector water supply pipe three (203) through an upper water outlet pipe, and the upper water outlet pipe is provided with an electric butterfly valve three V3; the lower water inlet is connected to the collector water supply pipe one (201) through a lower water inlet pipe, and the lower water inlet pipe is provided with an electric butterfly valve two V2.

6. The solar energy and air energy dual heat source heat pump system according to claim 5, characterized in that: The collector water supply pipe 1 (201) is connected to the collector return pipe 1 (301) through a bypass pipe 1 (101), and an electric butterfly valve 10 V10 is provided on the bypass pipe 1 (101).

7. The solar energy and air energy dual heat source heat pump system according to claim 1, characterized in that: The heat pump system (51) comprises: A condenser (2) is connected to the user-side heating pipe (501) via a water-side loop water inlet pipe, wherein a second terminal valve V22 is provided on the water-side loop water inlet pipe; The water-cooled evaporator (6) is connected to the condenser (2) via a refrigerant low-pressure side liquid pipe (406), and a solenoid valve (2) V12 is provided on the refrigerant low-pressure side liquid pipe (406).

8. The solar energy and air energy dual heat source heat pump system according to claim 7, characterized in that: The heat pump system (51) further includes an air-cooled evaporator (5), which is connected to the refrigerant low-pressure side liquid pipe three (406) via the refrigerant low-pressure side liquid pipe two (405), and a solenoid valve one V11 is provided on the refrigerant low-pressure side liquid pipe two (405).

9. The solar energy and air energy dual heat source heat pump system according to claim 8, characterized in that: The water-cooled evaporator (6) comprises: The heat exchange coil E1 has a water inlet connected to the heat collector water supply pipe 4 (204), and a water outlet connected to the heat collector return pipe 1 (301) through the heat collector return pipe 2 (302); The water inlet and outlet of the heat exchange coil E2 are both connected to the user-side cooling pipe (601).

10. The solar energy and air energy dual heat source heat pump system according to claim 9, characterized in that: The water inlet pipe of the heat exchange coil E2 is provided with an end valve three V23.

Images