A cascade heat pump defrosting system
By using heat storage and liquid reservoir in the defrosting system of a stacked heat pump, the problem of poor stability of the system at low temperatures is solved, ensuring the normal operation of the compressor and the stability of the system.
Patent Information
- Application Number
- CN202420458653.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-11
- Publication Date
- 2025-04-01
- Estimated Expiration
- 2034-03-11
AI Technical Summary
The existing stacked heat pump defrosting system has poor system stability at low temperatures. The high-temperature water-side heat absorption leads to a high evaporation temperature of the compressor, which may damage the compressor.
Use a heat storage device to store heat. When defrosting, absorb heat from the liquid reservoir for defrosting to avoid excessive system temperature and ensure normal operation of the compressor.
It improves the stability of the system, avoids the problem of temperature exceeding the compressor operating range, and makes the system operation more stable.
Smart Images
Figure CN222703568U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of temperature control, in particular to a cascade heat pump defrosting system. Background Art
[0002] Air source heat pumps are increasingly used for heating in cold northern regions. According to the characteristics of heating, when the ambient temperature is relatively low, buildings generally require a higher water supply temperature to meet heating needs. The cascade heat pump uses a two-stage compressor cascade design to provide a higher water outlet temperature at low temperatures to meet heating or hot water needs at low temperatures. The fin evaporator of the cascade heat pump absorbs heat from the environment and will frost at low temperatures. The existing defrosting method defrosts by absorbing heat from the high-temperature water side, and the system stability is poor. Absorbing heat from high-temperature water will cause the compressor evaporation temperature to be too high, exceeding the compressor operating range and causing damage to the compressor. Therefore, a solution that can make the system more stable is needed to solve the above technical problems. Utility Model Content
[0003] In order to solve the above technical problems, the utility model proposes a cascade heat pump defrost system, which stores a part of the heat through a heat storage device, and absorbs heat from the liquid storage device to defrost the first heat exchanger during defrosting; in addition, the setting of the heat storage device can prevent the system temperature from being too high, and can maintain the normal operation of the compressor. It has the advantage of simple structure, and can prevent the temperature from exceeding the operating range of the compressor, making the movement of the system more stable.
[0004] Specifically, the utility model proposes a cascade heat pump defrosting system, including a first compressor, a second compressor, a first heat exchanger, a second heat exchanger, an intermediate heat exchanger, a four-way valve and a heat storage device.
[0005] The exhaust port of the first compressor is connected to the first interface of the four-way valve, the fourth interface of the four-way valve is connected to one end of the first heat exchange channel of the intermediate heat exchanger, and the other end of the first heat exchange channel is connected to the input port of the heat storage, the output port of the heat storage is connected to the input port of the first heat exchanger through the air pressure control component, the output port of the first heat exchanger is connected to the second interface of the heat exchanger, and the third interface of the heat exchanger is connected to the air inlet of the first compressor;
[0006] The exhaust port of the second compressor is connected to the input port of the second heat exchanger, the output port of the second heat exchanger is connected to one end of the second heat exchange channel of the intermediate heat exchanger, and the other end of the second heat exchange channel is used to connect to the air inlet of the second compressor.
[0007] Preferably, the air pressure control assembly includes a first electronic expansion valve, and the first electronic expansion valve is used to connect the heat storage device and the first heat exchanger.
[0008] Preferably, the air pressure control assembly further includes a second electronic expansion valve and an economizer, the economizer having a third heat exchange channel and a fourth heat exchange channel, one end of the third heat exchange channel is connected to the first heat exchange channel of the heat storage through a first pipeline, and the other end of the third heat exchange channel is connected to the first heat exchanger through a second pipeline;
[0009] The second pipeline is connected to one end of the fourth heat exchange channel through a branch pipe, the other end of the fourth heat exchange channel is connected to the air supply port of the first compressor through a third pipeline, and the second electronic expansion valve is installed on the branch pipe.
[0010] Preferably, the first electronic expansion valve is installed on the second pipeline, and the first electronic expansion valve is located between the branch pipe and the first heat exchanger.
[0011] Preferably, a first gas-liquid separator is provided between the third connection of the four-way valve and the air inlet of the first compressor.
[0012] Preferably, a liquid storage tank is provided on the first pipeline.
[0013] Preferably, a third electronic expansion valve is provided between the second heat exchanger and the second heat exchange channel of the intermediate heat exchanger.
[0014] Preferably, a second gas-liquid separator is provided between the air inlet of the second compressor and the second heat exchange channel of the intermediate heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the drawings required to be used in the embodiments or the description of the prior art will be briefly introduced below.
[0016] Figure 1 is a structural schematic diagram of a cascade heat pump defrosting system proposed in this embodiment;
[0017] Figure 2 yes Figure 1 Schematic diagram of the local enlarged structure at point A in the middle.
[0018] The reference numerals in the accompanying drawings are as follows:
[0019] 11-first compressor; 12-second compressor; 13-first heat exchanger; 14-second heat exchanger; 15-intermediate heat exchanger; 16-four-way valve; 17-heat storage; 18-first interface; 19-second interface; 20-third interface; 21-fourth interface; 22-first electronic expansion valve; 23-second electronic expansion valve; 24-economizer; 25-first pipeline; 26-second pipeline; 27-branch pipe; 28-third pipeline; 29-first gas-liquid separator; 30-liquid storage tank; 31-third electronic expansion valve; 32-second gas-liquid separator. DETAILED DESCRIPTION
[0020] The technical solution of the present application is further described below in conjunction with specific embodiments, but the present application is not limited to these embodiments.
[0021] like Figure 1 and Figure 2 As shown, this embodiment proposes a cascade heat pump defrosting system, including a first compressor 11, a second compressor 12, a first heat exchanger 13, a second heat exchanger 14, an intermediate heat exchanger 15, a four-way valve 16 and a heat storage device 17.
[0022] The exhaust port of the first compressor 11 is connected to the first interface 18 of the four-way valve 16, the fourth interface 21 of the four-way valve 16 is connected to one end of the first heat exchange channel of the intermediate heat exchanger 15, and the other end of the first heat exchange channel is connected to the input port of the heat storage 17, the output port of the heat storage 17 is connected to the input port of the first heat exchanger 13 through the air pressure control component, the output port of the first heat exchanger 13 is connected to the second interface 19 of the heat exchanger, and the third interface 20 of the heat exchanger is connected to the air inlet of the first compressor 11;
[0023] The exhaust port of the second compressor 12 is connected to the input port of the second heat exchanger 14 , the output port of the second heat exchanger 14 is connected to one end of the second heat exchange channel of the intermediate heat exchanger 15 , and the other end of the second heat exchange channel is used to connect to the air inlet of the second compressor 12 .
[0024] The technical effect of this solution is that: this solution has the advantage of simple structure, and can prevent the temperature from exceeding the operating range of the compressor, making the movement of the system more stable.
[0025] The second heat exchanger 14 exchanges heat with the external water flow. A portion of heat is stored in the heat storage 17, and heat is absorbed from the liquid storage during defrosting to defrost the first heat exchanger 13. In addition, the setting of the heat storage 17 can prevent the system temperature from being too high and maintain the normal operation of the compressor.
[0026] As an implementation of this embodiment, the air pressure control assembly includes a first electronic expansion valve 22, and the first electronic expansion valve 22 is used to connect the heat storage 17 and the first heat exchanger 13. Further, the air pressure control assembly also includes a second electronic expansion valve 23 and an economizer 24, the economizer 24 has a third heat exchange channel and a fourth heat exchange channel, one end of the third heat exchange channel is connected to the first heat exchange channel of the heat storage 17 through the first pipeline 25, and the other end of the third heat exchange channel is connected to the first heat exchanger 13 through the second pipeline 26;
[0027] The second pipeline 26 is connected to one end of the fourth heat exchange channel through the branch pipe 27 , and the other end of the fourth heat exchange channel is connected to the air supply port of the first compressor 11 through the third pipeline 28 . The second electronic expansion valve 23 is installed on the branch pipe 27 .
[0028] This solution can improve the working stability of the first compressor 11.
[0029] The air pressure control component can maintain the cooling or heating of the system, and when the air intake of the first compressor 11 is insufficient, under the action of the second electronic expansion valve 23, the medium flows into the fourth heat exchange channel and flows into the air supply port of the first compressor 11 after heat exchange, so as to improve the stability of the compressor operation.
[0030] Furthermore, a first electronic expansion valve 22 is installed on the second pipeline 26 , and the first electronic expansion valve 22 is located between the branch pipe 27 and the first heat exchanger 13 .
[0031] Among them, in the field of temperature control, the application of electronic expansion valves belongs to the existing technology, and the working principle of this part will not be described in detail.
[0032] As an implementation of this embodiment, a first gas-liquid separator 29 is provided between the third connection of the four-way valve 16 and the air inlet of the first compressor 11. This solution separates the medium into gas and liquid through the first gas-liquid separator 29, so that the operation of the first compressor 11 is more stable.
[0033] Furthermore, a liquid storage tank 30 is provided on the first pipeline 25 .
[0034] Furthermore, a third electronic expansion valve 31 is provided between the second heat exchanger 14 and the second heat exchange channel of the intermediate heat exchanger 15. It is used to adjust the pressure and flow rate of the medium flowing out of the second heat exchanger 14.
[0035] As an implementation of this embodiment, a second gas-liquid separator 32 is provided between the air inlet of the second compressor 12 and the second heat exchange channel of the intermediate heat exchanger 15. It is used to separate the gas and liquid of the medium flowing into the second compressor 12, so that the operation of the second compressor 12 is more stable.
[0036] The working principle of this embodiment is as follows:
[0037] In the heating mode: the first compressor 11 and the second compressor 12 are both working. The first port 18 and the fourth port 21 of the four-way valve 16 are connected; the second port 19 and the third port 20 are connected.
[0038] The medium in the first compressor 11 flows into the first heat exchange channel of the intermediate heat exchanger 15 through the first interface 18 and the second interface 19 of the four-way valve 16, and the high-temperature medium in the first heat exchange channel exchanges heat with the low-temperature medium in the second heat exchange channel. After being heated, the medium in the second heat exchange channel flows into the second compressor 12 through the second gas-liquid separator 32, and then the high-temperature and high-pressure medium heats the external water source through the second heat exchanger 14 to meet the external heating demand. In addition, the medium in the first heat exchange channel of the intermediate heat exchanger 15 flows into the heat storage 17, and part of the heat is stored in the heat storage 17. Then the medium flows into the second interface 19 of the four-way valve 16 through the liquid storage tank 30, the third heat exchange channel of the economizer 24, the first electronic expansion valve 22 and the first heat exchanger 13, and then the medium flows into the first compressor 11 from the third interface 20 of the four-way valve 16 and the first gas-liquid separator 29. Part of the medium on the second pipeline 26 flows into the fourth heat exchange channel of the economizer 24 through the second electronic expansion valve 23 , and then continues to flow into the air supply port of the first compressor 11 .
[0039] In the defrosting mode, the first compressor 11 works, and the second compressor 12 does not work. The first port 18 and the second port 19 of the four-way valve 16 are connected, and the third port 20 and the fourth port 21 are connected.
[0040] The medium in the liquid storage tank 30 absorbs heat through the heat storage device 17, and then passes through the first heat exchange channel of the intermediate heat exchanger 15 and flows into the fourth interface 21 of the four-way valve 16, and then flows out from the third interface 20 of the four-way valve 16 and flows into the air inlet of the first compressor 11 through the first gas-liquid separator 29. The compressed high-temperature and high-pressure medium flows into the first heat exchanger 13 through the first interface 18 and the second interface 19 of the four-way valve 16 to defrost the first heat exchanger 13.
[0041] For ordinary technicians in this field, several modifications and improvements can be made without departing from the creative concept of the utility model, which all fall within the protection scope of the utility model.
Claims
1. A cascade heat pump defrosting system, characterized in that: The invention comprises a first compressor (11), a second compressor (12), a first heat exchanger (13), a second heat exchanger (14), an intermediate heat exchanger (15), a four-way valve (16) and a heat storage device (17), The exhaust port of the first compressor (11) is connected to the first interface (18) of the four-way valve (16), the fourth interface (21) of the four-way valve (16) is connected to one end of the first heat exchange channel of the intermediate heat exchanger (15), and the other end of the first heat exchange channel is connected to the input port of the heat storage device (17), the output port of the heat storage device (17) is connected to the input port of the first heat exchanger (13) through the air pressure control component, the output port of the first heat exchanger (13) is connected to the second interface (19) of the heat exchanger, and the third interface (20) of the heat exchanger is connected to the air inlet of the first compressor (11); The exhaust port of the second compressor (12) is connected to the input port of the second heat exchanger (14), the output port of the second heat exchanger (14) is connected to one end of the second heat exchange channel of the intermediate heat exchanger (15), and the other end of the second heat exchange channel is used to connect to the air inlet of the second compressor (12).
2. The cascade heat pump defrosting system according to claim 1, characterized in that: The gas pressure control component comprises a first electronic expansion valve (22), and the first electronic expansion valve (22) is used to connect the heat storage device (17) and the first heat exchanger (13).
3. The cascade heat pump defrosting system according to claim 2, characterized in that: The gas pressure control assembly further comprises a second electronic expansion valve (23) and an economizer (24), wherein the economizer (24) has a third heat exchange channel and a fourth heat exchange channel, wherein one end of the third heat exchange channel is connected to the first heat exchange channel of the heat storage device (17) via a first pipeline (25), and the other end of the third heat exchange channel is connected to the first heat exchanger (13) via a second pipeline (26); The second pipeline (26) is connected to one end of the fourth heat exchange channel through a branch pipe (27), and the other end of the fourth heat exchange channel is connected to the air supply port of the first compressor (11) through a third pipeline (28), and the second electronic expansion valve (23) is installed on the branch pipe (27).
4. The cascade heat pump defrosting system according to claim 3, characterized in that: The first electronic expansion valve (22) is installed on the second pipeline (26), and the first electronic expansion valve (22) is located between the branch pipe (27) and the first heat exchanger (13).
5. The cascade heat pump defrosting system according to claim 3, characterized in that: A first gas-liquid separator (29) is provided between the third connection of the four-way valve (16) and the air inlet of the first compressor (11).
6. The cascade heat pump defrosting system according to claim 3, characterized in that: A liquid storage tank (30) is provided on the first pipeline (25).
7. The cascade heat pump defrosting system according to claim 1, characterized in that: A third electronic expansion valve (31) is provided between the second heat exchange channel of the second heat exchanger (14) and the intermediate heat exchanger (15).
8. The cascade heat pump defrosting system according to claim 1, characterized in that: A second gas-liquid separator (32) is provided between the air inlet of the second compressor (12) and the second heat exchange channel of the intermediate heat exchanger (15).