Cascade type air source heat pump unit with solar hot air

Abstract

The utility model discloses a cascade type air source heat pump unit with solar hot air. The cascade type air source heat pump unit comprises a low-temperature side system, a high-temperature side system and a middle heat exchange system. The low-temperature side system comprises a low-temperature side compressor, a low-temperature side throttling component and a low-temperature side evaporator; the high-temperature side system comprises a high-temperature side compressor, a high-temperature side heat exchanger and a high-temperature side throttling component. The low-temperature side system is used for absorbing heat from the air side, high evaporation temperature is provided for the high-temperature side system through the middle heat exchange system, it is guaranteed that the heat pump unit has a stable heat source, and the heating efficiency and the water outlet temperature of the heat pump unit can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of air source heat pump hot water, in particular to a cascade air source heat pump unit with solar hot wind. Background Art

[0002] Air source heat pump units extract heat from low-temperature air through compressors and other equipment, and then release the heat into the room to achieve the purpose of heating. They are widely used in residential, commercial and industrial occasions.

[0003] In recent years, the demand for energy-efficient, environmentally friendly and green energy has been increasing, and heat pump products represented by air source heat pumps have ushered in good development opportunities. The upper limit of the outlet water temperature of traditional low-temperature units is 60℃, which cannot meet the use requirements in special industrial fields.

[0004] Traditional air source heat pump units use single-stage compression. When the system is used to heat water, the pressure is too high, the evaporation temperature is too low, the energy consumption is high, and it is greatly affected by the environment. It cannot be used in low ambient temperature situations and the water outlet temperature is limited. On the other hand, at low ambient temperatures, less energy needs to be absorbed from the air, and frost is prone to occur, which affects the heating effect of the system. Utility Model Content

[0005] In view of the defects in the prior art, the utility model provides a cascade air source heat pump unit with solar hot wind to improve the heating efficiency and water outlet temperature of the heat pump unit.

[0006] The utility model provides a cascade air source heat pump unit with solar hot wind, comprising a low temperature side system, a high temperature side system and an intermediate heat exchange system;

[0007] The low-temperature side system includes a low-temperature side compressor, a low-temperature side throttling component and a low-temperature side evaporator, the output end of the low-temperature side compressor is connected to the first medium inlet of the intermediate heat exchange system through a pipeline, the first medium outlet of the intermediate heat exchange system is sequentially connected to the low-temperature side throttling component through a pipeline, the low-temperature side throttling component is connected to the low-temperature side evaporator through a pipeline, and the low-temperature side evaporator is connected to the input end of the low-temperature side compressor through a pipeline;

[0008] The high-temperature side system includes a high-temperature side compressor, a high-temperature side heat exchanger and a high-temperature side throttling component. The output end of the high-temperature side compressor is connected to the first medium inlet of the high-temperature side heat exchanger through a pipeline, the first medium outlet of the high-temperature side heat exchanger is connected to the high-temperature side throttling component through a pipeline, the high-temperature side throttling component is connected to the second medium inlet of the intermediate heat exchange system through a pipeline, the second medium outlet pipeline of the intermediate heat exchange system is connected to the input end of the high-temperature side compressor, the second medium inlet of the high-temperature side heat exchanger is connected to the water inlet pipe, and the second medium outlet of the high-temperature side heat exchanger is connected to the water outlet pipe.

[0009] Further, the low-temperature side evaporator includes a fin heat exchanger and an axial flow fan for accelerating the flow of air through the fin heat exchanger.

[0010] Further, a solar hot air system is further included, and the solar hot air system is used to supply hot air to the fin heat exchanger.

[0011] Further, the high-temperature side heat exchanger adopts a coaxial heat exchanger.

[0012] Further, the low-temperature side system further includes a four-way reversing valve and a check valve group;

[0013] The first interface of the four-way reversing valve is connected to the output end of the low-temperature side compressor through a pipeline, the second interface of the four-way reversing valve is connected to the third medium inlet of the high-temperature side heat exchanger through a pipeline, the third interface of the four-way reversing valve is connected to the low-temperature side evaporator through a pipeline, and the fourth interface of the four-way reversing valve is connected to the input end of the low-temperature side compressor through a pipeline;

[0014] The check valve group includes two flow channels, a first interface connected to one ends of the two flow channels, a second interface connected to the other ends of the two flow channels, a third interface and a fourth interface respectively connected to the middle parts of the two flow channels, two first check valves allowing fluid to flow to both ends and arranged in the flow channels on both sides of the third interface, and two second check valves allowing fluid to flow to the middle and arranged in the flow channels at both ends of the fourth interface. The first interface of the check valve group is connected to the third medium outlet of the high-temperature side heat exchanger through a pipeline, the second interface of the check valve group is connected to the low-temperature side evaporator through a pipeline, the third interface of the check valve group is connected to the first medium inlet of the intermediate heat exchange system through a pipeline, and the fourth interface of the check valve group is connected to the low-temperature side throttling component through a pipeline.

[0015] Further, the low-temperature side system further includes a liquid receiver arranged on the pipeline between the intermediate heat exchange system and the low-temperature side throttling component.

[0016] Further, the low-temperature side system further includes an economizer. The first medium inlet and the first medium outlet of the economizer are connected in series on the pipeline between the intermediate heat exchange system and the low-temperature side throttling component. The second medium inlet of the economizer is connected to the downstream of the first medium outlet of the economizer through an enthalpy-increasing throttling component. The second medium outlet of the economizer is connected to the enthalpy-increasing port of the low-temperature side compressor through a pipeline.

[0017] Further, gas-liquid separators are arranged on the pipelines at the input ends of the low-temperature side compressor and the high-temperature side compressor.

[0018] The beneficial effects of the present utility model are embodied in:

[0019] When the unit is operating, the low-temperature side compressor compresses the low-temperature and low-pressure gaseous refrigerant in the low-temperature side system into a high-temperature and high-pressure gaseous refrigerant and sends it to the high-temperature side of the intermediate heat exchange system to provide heat for its low-temperature side, cools itself and condenses into a high-temperature and high-pressure liquid refrigerant. The high-temperature and high-pressure liquid refrigerant passes through the throttling component on the low-temperature side to reduce the pressure, becoming a mixture of low-temperature and low-pressure liquid and gaseous refrigerant, and then is sent to the low-temperature side evaporator. The refrigerant absorbs heat from the surrounding low-temperature environment (such as outdoor air), evaporates into a low-temperature and low-pressure gaseous refrigerant, and then is inhaled by the low-temperature side compressor again to repeat the above cycle.

[0020] The high-temperature side compressor operates simultaneously. The low-temperature and low-pressure gaseous refrigerant in the high-temperature side system is compressed into a high-temperature and high-pressure gaseous refrigerant and sent to the high-temperature side heat exchanger. At the same time, the outer water supply system sends water to the high-temperature side heat exchanger to take away the heat generated by the condensation of the high-temperature and high-pressure liquid refrigerant in the high-temperature side system, producing high-temperature hot water. The high-temperature and high-pressure gaseous refrigerant is cooled and condensed into a high-temperature and high-pressure liquid refrigerant after passing through the high-temperature side heat exchanger, and then passes through the throttling component on the high-temperature side to reduce the pressure, becoming a mixture of low-temperature and low-pressure liquid and gaseous refrigerant, and then is sent to the low-temperature side of the intermediate heat exchange system to exchange energy with the high-temperature side of the intermediate heat exchange system, evaporates into a low-temperature and low-pressure gaseous refrigerant, and then is inhaled by the high-temperature side compressor again to repeat the above cycle.

[0021] Compared with the prior art, the present application uses the low-temperature side system to absorb heat from the air side, provides a high evaporation temperature for the high-temperature side system through the intermediate heat exchange system, ensures that it has a stable heat source, and can improve the heating efficiency and the outlet water temperature of the heat pump unit. Brief Description of the Drawings

[0022] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0023] Figure 1 It is a schematic structural diagram of an embodiment of the present invention;

[0024] Figure 2 It is a schematic system diagram of an embodiment of the present invention.

[0025] In the attached drawings, 100 is the low-temperature side system; 110 is the low-temperature side compressor; 120 is the low-temperature side throttling component; 130 is the low-temperature side evaporator; 131 is the fin heat exchanger; 132 is the axial flow fan; 140 is the four-way reversing valve; 150 is the check valve group; 160 is the liquid receiver; 170 is the economizer; 171 is the enthalpy-increasing throttling component; 180 is the gas-liquid separator; 200 is the high-temperature side system; 210 is the high-temperature side compressor; 220 is the high-temperature side heat exchanger; 230 is the high-temperature side throttling component; 300 is the intermediate heat exchange system; 400 is the solar hot air system. Detailed implementation manners

[0026] The embodiments of the technical solution of the present utility model will be described in detail below with reference to the attached drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present utility model, so they are only examples and cannot be used to limit the protection scope of the present utility model.

[0027] It should be noted that unless otherwise specified, the technical terms or scientific terms used in this application should have the ordinary meanings understood by those skilled in the art to which the present utility model belongs.

[0028] As Figure 1 and Figure 2 shown, the embodiment of the present utility model provides a cascade air source heat pump unit with solar hot air, which includes a low-temperature side system 100, a high-temperature side system 200 and an intermediate heat exchange system 300.

[0029] The low-temperature side system 100 includes a low-temperature side compressor 110, a low-temperature side throttling component 120 and a low-temperature side evaporator 130. The output end of the low-temperature side compressor 110 is connected to the first medium inlet of the intermediate heat exchange system 300 through a pipeline. The first medium outlet of the intermediate heat exchange system 300 is sequentially connected to the low-temperature side throttling component 120 through a pipeline. The low-temperature side throttling component 120 is connected to the low-temperature side evaporator 130 through a pipeline. The low-temperature side evaporator 130 is connected to the input end of the low-temperature side compressor 110 through a pipeline.

[0030] In this embodiment, the low-temperature side evaporator 130 includes a fin heat exchanger 131 and an axial flow fan 132 for accelerating the airflow through the fin heat exchanger 131. Preferably, this embodiment further includes a solar hot air system 400. The solar hot air system 400 is used to provide hot air to the fin heat exchanger 131. The solar hot air system 400 sends the hot air generated by the external solar system through the system air duct to the fin heat exchanger 131 to provide sufficient air heat source for it, reduce the influence of the ambient temperature, and achieve the goal of normal operation when the ambient temperature is below -12°C and the water outlet temperature is above 60°C.

[0031] The high-temperature side system 200 includes a high-temperature side compressor 210, a high-temperature side heat exchanger 220, and a high-temperature side throttling component 230. The output end of the high-temperature side compressor 210 is connected to the first medium inlet of the high-temperature side heat exchanger 220 through a pipeline. The high-temperature side heat exchanger 220 uses a coaxial heat exchanger. The first medium outlet of the high-temperature side heat exchanger 220 is connected to the high-temperature side throttling component 230 through a pipeline. The high-temperature side throttling component 230 is connected to the second medium inlet of the intermediate heat exchange system 300 through a pipeline. The pipeline of the second medium outlet of the intermediate heat exchange system 300 is connected to the input end of the high-temperature side compressor 210. The second medium inlet of the high-temperature side heat exchanger 220 is connected to a water inlet pipe, and the second medium outlet of the high-temperature side heat exchanger 220 is connected to a water outlet pipe.

[0032] In this embodiment, the low-temperature side system 100 selects a variable-frequency gas-injected enhanced enthalpy compressor 101. Through its variable-frequency adjustment, it absorbs heat from the air and provides heat energy for the high-temperature side system 200 through the intermediate heat exchanger system, ensuring a high evaporation temperature on the high-temperature side and making it unaffected by the ambient temperature. This system uses the environmentally friendly refrigerant R1410a to ensure safe and stable operation under low ambient temperature conditions.

[0033] The high-temperature side system 200 in this embodiment is the part that mainly produces high-temperature hot water. It selects a compressor with a high condensation temperature to ensure that the unit can produce hot water above 60°C. This system uses the environmentally friendly refrigerant R134a to ensure that the pressure does not become too high under the premise of its high condensation temperature.

[0034] During the operation of the unit, the low-temperature side compressor 110 compresses the low-temperature and low-pressure gaseous refrigerant in the low-temperature side system 100 into a high-temperature and high-pressure gaseous refrigerant and sends it to the high-temperature side of the intermediate heat exchange system 300 to provide heat for its low-temperature side. It cools itself and condenses into a high-temperature and high-pressure liquid refrigerant. The high-temperature and high-pressure liquid refrigerant passes through the low-temperature side throttling component 120 to throttle down the pressure and becomes a mixture of low-temperature and low-pressure liquid and gaseous refrigerant, and then is sent to the low-temperature side evaporator 130. The refrigerant absorbs heat from the surrounding low-temperature environment (such as outdoor air), evaporates into a low-temperature and low-pressure gaseous refrigerant, and then is inhaled by the low-temperature side compressor 110 again to repeat the above cycle.

[0035] The high-temperature-side compressor 210 operates simultaneously. The low-temperature and low-pressure gaseous refrigerant in the high-temperature-side system 200 is compressed into a high-temperature and high-pressure gaseous refrigerant and sent to the high-temperature-side heat exchanger 220. At the same time, the outer water supply system sends water to the high-temperature-side heat exchanger 220 to take away the heat generated by the condensation of the high-temperature and high-pressure liquid refrigerant in the high-temperature-side system 200, producing high-temperature hot water. The high-temperature and high-pressure gaseous refrigerant is cooled and condensed into a high-temperature and high-pressure liquid refrigerant after passing through the high-temperature-side heat exchanger 220, and then passes through the high-temperature-side throttling component 230 for throttling and pressure reduction, becoming a mixture of low-temperature and low-pressure liquid and gaseous refrigerant, and then sent to the low-temperature side of the intermediate heat exchange system 300 for energy exchange with the high-temperature side of the intermediate heat exchange system 300, evaporating into a low-temperature and low-pressure gaseous refrigerant, and then being sucked into the high-temperature-side compressor 210 again to repeat the above cycle.

[0036] Compared with the prior art, the present application utilizes the low-temperature-side system 100 to absorb heat from the air side, provides a high evaporation temperature for the high-temperature-side system 200 through the intermediate heat exchange system 300, ensures that it has a stable heat source, can improve the heating efficiency of the heat pump unit and the water outlet temperature, and can achieve the goal of the water outlet temperature reaching 80°C.

[0037] In one embodiment, referring to Figure 2 , the low-temperature-side system 100 further includes a four-way reversing valve 140 and a check valve group 150.

[0038] The first interface of the four-way reversing valve 140 is connected to the output end of the low-temperature-side compressor 110 through a pipeline. The second interface of the four-way reversing valve 140 is connected to the third medium inlet of the high-temperature-side heat exchanger 220 through a pipeline. The third interface of the four-way reversing valve 140 is connected to the low-temperature-side evaporator 130 through a pipeline. The fourth interface of the four-way reversing valve is connected to the input end of the low-temperature-side compressor 110 through a pipeline.

[0039] The check valve group 150 includes two flow channels, a first interface connected to one end of the two flow channels, a second interface connected to the other end of the two flow channels, a third interface and a fourth interface respectively connected to the middle parts of the two flow channels, two first check valves allowing fluid to flow in both directions and arranged in the flow channels on both sides of the third interface, and two second check valves allowing fluid to flow towards the middle and arranged in the flow channels at both ends of the fourth interface. The first interface of the check valve group 150 is connected to the third medium outlet of the high-temperature-side heat exchanger 220 through a pipeline. The second interface of the check valve group 150 is connected to the low-temperature-side evaporator 130 through a pipeline. The third interface of the check valve group 150 is connected to the first medium inlet of the intermediate heat exchange system 300 through a pipeline. The fourth interface of the check valve group 150 is connected to the low-temperature-side throttling component 120 through a pipeline.

[0040] When the unit is operating normally, the high-temperature and high-pressure liquid refrigerant generated by the low-temperature side compressor 110 sequentially passes through the high-temperature side heat exchanger 220 and a flow path in the one-way valve group 150 and then enters the intermediate heat exchange system 300. After passing through the intermediate heat exchange system 300, the refrigerant sequentially passes through the low-temperature side throttling component 120, another flow path in the one-way valve group 150, and the low-temperature side evaporator 130 and then returns to the low-temperature side compressor 110. When the low-temperature side evaporator 130 is frosted, the defrosting mode can be turned on. When starting the defrosting mode, the high-temperature side system 200 does not operate, and the four-way reversing valve 140 of the low-temperature side system 100 automatically switches, so that the high-temperature and high-pressure gaseous refrigerant generated by the low-temperature side compressor 110 is sent to the low-temperature side evaporator 130 for heating defrosting. The refrigerant cools itself and condenses into a high-temperature and high-pressure liquid refrigerant, and then sequentially enters the intermediate heat exchange system 300 through a flow path in the one-way valve group 150. The liquid refrigerant coming out of the intermediate heat exchange system 300 is throttled and depressurized by the low-temperature side throttling component 120, and then enters the high-temperature side heat exchanger 220 through another flow path in the one-way valve group 150. At this time, the high-temperature side heat exchanger 220 serves as the evaporator of the low-temperature side system 100. The refrigerant of the low-temperature side system 100 evaporates and absorbs heat through the high-temperature side heat exchanger 220 to form a low-temperature and low-pressure gaseous condenser, and finally returns to the low-temperature side compressor 110 to continue compression. Through this cycle, the defrosting of the low-temperature side evaporator 130 can be realized.

[0041] The low-temperature side system 100 further includes a liquid receiver 160 provided on the pipeline between the intermediate heat exchange system 300 and the low-temperature side throttling component 120. The liquid receiver 160 can supply or store excess refrigerant, keep the system pressure relatively stable, and ensure the continuity of the refrigeration effect.

[0042] The low-temperature side system 100 further includes an economizer 170, and the economizer 170 can be used to improve performance and efficiency. Specifically, refer to Figure 2 , the first medium inlet and the first medium outlet of the economizer 170 are connected in series on the pipeline between the intermediate heat exchange system 300 and the low-temperature side throttling component 120. The second medium inlet of the economizer 170 is connected to the downstream of the first medium outlet of the economizer 170 through an enthalpy-increasing throttling component 171. The second medium outlet of the economizer 170 is connected to the enthalpy-increasing port of the low-temperature side compressor 110 through a pipeline. The liquid refrigerant is divided into two paths after coming out of the economizer 170, one is the main path and the other is the auxiliary path. The refrigerant in the main path enters the low-temperature side throttling component 120, is throttled and depressurized, and then enters the low-temperature side evaporator 130 for evaporation, and then returns to the input end of the low-temperature side compressor 110. When certain conditions are met, the enthalpy-increasing throttling component 171 opens, and part of the refrigerant is throttled and depressurized by the enthalpy-increasing throttling component 171 and then enters the economizer 170, exchanges heat with the liquid refrigerant entering the economizer 170 in the economizer 170, absorbs heat and evaporates into gaseous refrigerant, and then the gaseous refrigerant enters the enthalpy-increasing port of the low-temperature side compressor 110.

[0043] Gas-liquid separators 180 are provided on the pipelines at the input ends of the low-temperature side compressor 110 and the high-temperature side compressor 210. The gas-liquid separators 180 are used to separate the refrigerant into gas and liquid, ensuring that only gaseous refrigerant enters the compressor and preventing liquid refrigerant from entering the compressor cylinder, thereby effectively preventing the occurrence of liquid slugging, which may cause serious faults such as valve plate damage and piston rupture of the compressor.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered by the scope of the claims and the description of the present invention.

Claims

1. A cascade air source heat pump unit with solar hot air, characterized in that: Including low temperature side system, high temperature side system and intermediate heat exchange system; The low-temperature side system includes a low-temperature side compressor, a low-temperature side throttling component and a low-temperature side evaporator, the output end of the low-temperature side compressor is connected to the first medium inlet of the intermediate heat exchange system through a pipeline, the first medium outlet of the intermediate heat exchange system is sequentially connected to the low-temperature side throttling component through a pipeline, the low-temperature side throttling component is connected to the low-temperature side evaporator through a pipeline, and the low-temperature side evaporator is connected to the input end of the low-temperature side compressor through a pipeline; The high-temperature side system includes a high-temperature side compressor, a high-temperature side heat exchanger and a high-temperature side throttling component. The output end of the high-temperature side compressor is connected to the first medium inlet of the high-temperature side heat exchanger through a pipeline, the first medium outlet of the high-temperature side heat exchanger is connected to the high-temperature side throttling component through a pipeline, the high-temperature side throttling component is connected to the second medium inlet of the intermediate heat exchange system through a pipeline, the second medium outlet pipeline of the intermediate heat exchange system is connected to the input end of the high-temperature side compressor, the second medium inlet of the high-temperature side heat exchanger is connected to the water inlet pipe, and the second medium outlet of the high-temperature side heat exchanger is connected to the water outlet pipe.

2. The cascade air source heat pump unit with solar hot wind according to claim 1, characterized in that: The low-temperature side evaporator includes a fin heat exchanger and an axial flow fan for accelerating airflow passing through the fin heat exchanger.

3. The cascade air source heat pump unit with solar hot wind according to claim 2, characterized in that: Also included is a solar hot wind system, which is used to provide hot wind to the fin heat exchanger.

4. The cascade air source heat pump unit with solar hot wind according to claim 1, characterized in that: The high temperature side heat exchanger is a coaxial heat exchanger.

5. The cascade air source heat pump unit with solar hot wind according to claim 1, characterized in that: The low temperature side system also includes a four-way reversing valve and a one-way valve group; The first interface of the four-way reversing valve is connected to the output end of the low-temperature side compressor through a pipeline, the second interface of the four-way reversing valve is connected to the third medium inlet of the high-temperature side heat exchanger through a pipeline, the third interface of the four-way reversing valve is connected to the low-temperature side evaporator through a pipeline, and the fourth interface of the fourth reversing valve is connected to the input end of the low-temperature side compressor through a pipeline; The one-way valve group includes two flow channels, a first interface connected to one end of the two flow channels, a second interface connected to the other end of the two flow channels, a third interface and a fourth interface respectively connected to the middle of the two flow channels, two first one-way valves arranged in the flow channels on both sides of the third interface for allowing fluid to flow to both ends, and two second one-way valves arranged in the flow channels on both ends of the fourth interface for allowing fluid to flow to the middle. The first interface of the one-way valve group is connected to the third medium outlet of the high-temperature side heat exchanger through a pipeline, the second interface of the one-way valve group is connected to the low-temperature side evaporator through a pipeline, the third interface of the one-way valve group is connected to the first medium inlet of the intermediate heat exchange system through a pipeline, and the fourth interface of the one-way valve group is connected to the low-temperature side throttling component through a pipeline.

6. The cascade air source heat pump unit with solar hot wind according to claim 5, characterized in that: The low temperature side system also includes a liquid storage device arranged on the pipeline between the intermediate heat exchange system and the low temperature side throttling component.

7. The cascade air source heat pump unit with solar hot wind according to claim 5, characterized in that: The low-temperature side system also includes an economizer, wherein a first medium inlet and a first medium outlet of the economizer are connected in series on a pipeline between the intermediate heat exchange system and the low-temperature side throttling component, a second medium inlet of the economizer is connected to the downstream of the first medium outlet of the economizer through an enthalpy-increasing throttling component, and the second medium outlet of the economizer is connected to the enthalpy-increasing port of the low-temperature side compressor through a pipeline.

8. The cascade air source heat pump unit with solar hot wind according to claim 1, characterized in that: Gas-liquid separators are provided on the pipelines at the input ends of the low-temperature side compressor and the high-temperature side compressor.

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