Cascade high-temperature heat pump system

Abstract

The utility model provides a cascade type high-temperature heat pump system which comprises a first-stage heat pump system, a second-stage heat pump system and a water supply system, the first-stage heat pump system comprises an enthalpy spraying compressor, a four-way valve, a first-stage heat exchanger, an evaporation assembly, a first-stage throttler and a separator, and the enthalpy spraying compressor is provided with an exhaust port, an air return port and an enthalpy spraying port. The evaporation assembly comprises a fin type heat exchanger with a fan, the fin type heat exchanger is provided with a supercooling heat exchanger, and an exhaust port of an enthalpy spraying compressor, a four-way valve, a first-stage heat exchanger, a first-stage throttler, the fin type heat exchanger, a separator and an air return port of the enthalpy spraying compressor are communicated and form a first-stage refrigerant circulation main path. And enthalpy spraying openings of the first-stage heat exchanger, the supercooling heat exchanger and the enthalpy spraying compressor are communicated and form an air suction loop. The environment sensible heat is fully utilized for heat exchange, the preheating effect is remarkable, a traditional electric auxiliary heating mode is replaced, the energy utilization rate is increased, the use cost is reduced, meanwhile, freezing and icing are effectively prevented, and the device is suitable for being used in the ultralow-temperature environment.

Description

Technical Field

[0001] The utility model relates to the technical field of heat pumps, in particular to a cascade high-temperature heat pump system. Background Art

[0002] The air source heat pump system includes a heat pump unit, which is mainly composed of a compressor, a condensing heat exchanger, a throttling device, and an evaporating heat exchanger connected in sequence through a working fluid pipeline to form a circulation loop.

[0003] At present, many air source heat pumps operate at low temperatures. Due to the large temperature difference, the temperature of the hot water generated is not too high, especially in the north where the outdoor temperature is -30℃. The existing heat pumps can only reach about 50℃, absorbing heat from the environment and then raising the water temperature to 50℃. The temperature difference in the middle is 80℃, and the existing heat pumps cannot meet the requirements.

[0004] To this end, existing heat pump systems commonly improve low-temperature heating capacity by adding electric auxiliary heating to the indoor unit to increase heating capacity and air outlet temperature. However, this structure is complex, has low energy efficiency, and is costly to manufacture. Particularly in ultra-low temperature environments, it can still experience insufficient performance, impacting user experience. Utility Model Content

[0005] The purpose of the utility model is to solve the shortcomings of the prior art and to propose a cascade high-temperature heat pump system.

[0006] The object of the invention of the utility model is achieved as follows: a cascade high-temperature heat pump system, comprising a primary heat pump system, a secondary heat pump system, and a water supply system, wherein the water supply system is connected to the primary heat pump system and the secondary heat pump system, wherein the primary heat pump system comprises an enthalpy spray compressor, a four-way valve, a primary heat exchanger, an evaporation component, a primary throttle, and a separator, the enthalpy spray compressor is provided with an exhaust port, an air return port, and an enthalpy spray port, the evaporation component comprises a fin-type heat exchanger with a fan, the fin-type heat exchanger is provided with a subcooling heat exchanger for preheating, the exhaust port of the enthalpy spray compressor, the four-way valve, the primary heat exchanger, the primary throttle, the fin-type heat exchanger, the separator, and the air return port of the enthalpy spray compressor are connected through a pipeline and form a primary refrigerant circulation main path, the primary heat exchanger, the subcooling heat exchanger, and the enthalpy spray port of the enthalpy spray compressor are connected through a pipeline and form an intake circuit with a subcooling function.

[0007] According to the above optimization, the intake circuit is provided with a first-stage secondary electronic expansion valve for controlling its on and off, and the refrigerant inlet end and the refrigerant output end of the first-stage secondary electronic expansion valve are respectively connected to the subcooling heat exchanger and the injection enthalpy port of the injection enthalpy compressor through pipelines.

[0008] According to the above optimization, the enthalpy spray compressor is set as a DC variable frequency compressor, the first-level throttle is set as a first-level main electronic expansion valve, and the fan is set as a DC brushless fan.

[0009] According to the above optimization, an intermediate heat exchanger is provided between the primary heat pump system and the secondary heat pump system. The first refrigerant inlet and the first refrigerant outlet of the intermediate heat exchanger are respectively connected to the refrigerant outlet end of the four-way valve and the refrigerant inlet of the primary heat exchanger. The second refrigerant inlet and the second refrigerant outlet of the intermediate heat exchanger are respectively connected to the refrigerant outlet of the secondary economizer and the refrigerant inlet end of the secondary heat pump system.

[0010] According to the above optimization, the secondary heat pump system includes a secondary compressor, a secondary water-side heat exchanger, and a secondary throttle. The secondary compressor, the secondary water-side heat exchanger, the secondary throttle, and the intermediate heat exchanger are connected by pipelines to form a secondary refrigerant circulation main path.

[0011] According to the above optimization, the secondary compressor is set as a fixed-frequency compressor; the secondary throttle is set as a secondary electronic expansion valve.

[0012] The advantages of the present invention are:

[0013] 1) Through the structural coordination of the finned heat exchanger, the subcooling heat exchanger and the fan, the sensible heat of the environment is fully utilized for heat exchange, and the preheating effect is significant. It replaces the traditional electric auxiliary heating method, improves energy utilization, reduces the cost of use, and effectively prevents freezing and ice, and is suitable for use in ultra-low temperature environments.

[0014] 2) The subcooling heat exchanger is connected to the spray enthalpy compressor with an intake circuit. Under the action of the intake circuit, the compression process of the spray enthalpy compressor is upgraded from only one time to two times, increasing the refrigerant circulation volume. In addition, during the heat exchange between the subcooling heat exchanger and the fin-type heat exchanger, the subcooling degree of the refrigerant entering the spray enthalpy compressor is further improved, thereby improving the system capacity to adapt to normal operation in ultra-low temperature environment.

[0015] 3) By adopting a DC variable frequency compressor, the operation is stable, the heating efficiency is improved, the energy attenuation is reduced, the energy efficiency ratio is improved, and the operating cost is saved.

[0016] 4) Under the action of the intermediate heat exchanger, the low-grade heat of the first-stage heat pump system is transferred to the second-stage heat pump system as heat for production, which can improve the energy efficiency of the first-stage heat pump system. Under the cascade effect of the two-stage heat pump system, the heating energy efficiency is greatly improved, and high-temperature hot water can be continuously produced in a low-temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a working principle diagram of a preferred embodiment of the utility model. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with the accompanying drawings.

[0019] According to the attached Figure 1 As shown, the cascade high-temperature heat pump system of the present invention includes a primary heat pump system, a secondary heat pump system, and a water supply system 14, which is connected to the primary and secondary heat pump systems. The primary heat pump system includes an enthalpy injection compressor 1, a four-way valve 2, a primary heat exchanger 3, an evaporation assembly, a primary throttle 4, and a separator 8. The enthalpy injection compressor 1 is equipped with an exhaust port, a return port, and an enthalpy injection port. The evaporation assembly includes a finned heat exchanger 5 with a fan 6, which is equipped with a subcooling heat exchanger 7 for preheating. The exhaust port of the spray enthalpy compressor 1, the four-way valve 2, the first-level heat exchanger 3, the first-level throttle 4, the finned heat exchanger 5, the separator 8, and the return air port of the spray enthalpy compressor 1 are connected through a pipeline to form a first-level refrigerant circulation main path, and the first-level heat exchanger 3, the subcooling heat exchanger 7, and the spray enthalpy port of the spray enthalpy compressor 1 are connected through a pipeline to form an intake circuit with a subcooling function.

[0020] During operation, the spray enthalpy compressor 1 compresses the refrigerant into high-pressure, high-temperature refrigerant gas, which is then transported from the exhaust port of the spray enthalpy compressor 1 through the four-way valve 2 to the primary heat exchanger 3. This high-pressure, high-temperature refrigerant gas undergoes heat exchange in the primary heat exchanger 3, producing high-temperature hot water. Subsequently, the primary throttle valve 4 is opened, and the partially condensed refrigerant is sequentially transported through the primary throttle valve 4 of the primary refrigerant circulation main path to the finned heat exchanger 5, the four-way valve 2, the separator 8, and then back into the spray enthalpy compressor 1 through the return air port for the next cycle of compression. During this period, due to the simultaneous operation of the fan 6 and the subcooling heat exchanger 7, another portion of the condensed refrigerant flows to the subcooling heat exchanger 7. Driven by the fan 6, the finned heat exchanger 5 and the subcooling heat exchanger 7 operate independently, exchanging heat with the heat source in the air, achieving the effect of heat exchange and evaporation. At this time, the supercooling heat exchanger 7 can also preheat the finned heat exchanger 5, replacing the traditional electric auxiliary heating method, improving energy utilization, reducing usage costs, and effectively preventing freezing and ice, adapting to use in ultra-low temperature environments.

[0021] Immediately, the first-stage secondary electronic expansion valve 9 activates, opening the intake return channel. The refrigerant, having undergone heat exchange in the subcooling heat exchanger 7 and then subcooled, flows back into the injection compressor 1 through the first-stage secondary electronic expansion valve 9 and the injection port of the injection compressor 1. This further enhances system capacity, enabling normal operation in ultra-low temperature environments, thanks to the subcooling heat exchanger 7. Furthermore, the subcooled refrigerant is replenished into the injection compressor 1 through the injection port, completing the compressor compression process twice, increasing the refrigerant circulation and boosting heating capacity.

[0022] In actual operation, the spray enthalpy compressor 1 is set as a DC variable frequency compressor, the first-stage throttle 4 is set as a first-stage main electronic expansion valve, and the fan 6 is set as a DC brushless fan.

[0023] Reference Figure 1 As shown, in further detail, an intermediate heat exchanger 10 is provided between the primary heat pump system and the secondary heat pump system. The first refrigerant inlet and the first refrigerant outlet of the intermediate heat exchanger 10 are respectively connected to the refrigerant outlet end of the four-way valve 2 and the refrigerant inlet of the primary heat exchanger 3. The second refrigerant inlet and the second refrigerant outlet of the intermediate heat exchanger 10 are respectively connected to the refrigerant outlet of the secondary economizer and the refrigerant inlet end of the secondary heat pump system.

[0024] Among them, the secondary heat pump system includes a secondary compressor 11, a secondary water-side heat exchanger 12, and a secondary throttle 13. The secondary compressor 11, the secondary water-side heat exchanger 12, the secondary throttle 13, and the intermediate heat exchanger 10 are connected by pipelines to form a secondary refrigerant circulation main path.

[0025] During operation, the secondary compressor 11 generates a high-temperature and high-pressure refrigerant airflow which is transported to the secondary water-side heat exchanger 12 for heat exchange to obtain high-temperature hot water. After condensation, the refrigerant is sequentially transported to the secondary throttle 13 and the intermediate heat exchanger 10. At this time, the refrigerant is transported back to the secondary compressor 11 after heat exchange, effectively preventing high-temperature non-condensable refrigerant from being output from the compressor, improving system capacity, and ensuring normal operation in ultra-low temperature environments.

[0026] At the same time, the intermediate heat exchanger 10 absorbs heat from the air in the finned heat exchanger 5 of the primary heat pump system and transfers it to the secondary heat pump system via the intermediate heat exchanger 10. The primary heat exchanger 3 of the secondary heat pump system then exchanges heat with the water in the water supply system 14. The cascade effect of the two-stage heat pump system significantly improves heating efficiency, enabling continuous production of high-temperature hot water even in low-temperature environments.

[0027] In practical applications, the secondary compressor 11 is configured as a fixed-frequency compressor, and the secondary throttle 13 is configured as a secondary electronic expansion valve, thereby improving the operational stability of the heat pump system, increasing heating efficiency, and saving operating costs.

[0028] The above specific embodiments are only specific implementation methods with better effects of the present invention. Any structure that is the same or equivalent to the cascade high-temperature heat pump system of the present invention is within the protection scope of the present invention.

Claims

1. A cascade high-temperature heat pump system, comprising a primary heat pump system, a secondary heat pump system, and a water supply system (14), wherein the water supply system (14) is connected to the primary heat pump system and the secondary heat pump system, and characterized in that: The primary heat pump system comprises an enthalpy spray compressor (1), a four-way valve (2), a primary heat exchanger (3), an evaporation component, a primary throttle (4), and a separator (8). The enthalpy spray compressor (1) is provided with an exhaust port, a return port, and an enthalpy spray port. The evaporation component comprises a finned heat exchanger (5) with a fan (6). The finned heat exchanger (5) is provided with a subcooling heat exchanger (7) for preheating. The exhaust port of the enthalpy spray compressor (1), the four-way valve (2), the primary heat exchanger (3), the primary throttle (4), the finned heat exchanger (5), the separator (8), and the return port of the enthalpy spray compressor (1) are connected through a pipeline to form a primary refrigerant circulation main path. The primary heat exchanger (3), the subcooling heat exchanger (7), and the enthalpy spray port of the enthalpy spray compressor (1) are connected through a pipeline to form an air intake circuit with a subcooling function.

2. The cascade high temperature heat pump system according to claim 1, characterized in that: The air intake circuit is provided with a primary secondary electronic expansion valve (9) for controlling its on and off operation. The refrigerant inlet end and the refrigerant outlet end of the primary secondary electronic expansion valve (9) are respectively connected to the subcooling heat exchanger (7) and the enthalpy injection port of the enthalpy injection compressor (1) through pipelines.

3. The cascade high temperature heat pump system according to claim 1, characterized in that: The enthalpy injection compressor (1) is a DC variable frequency compressor, the primary throttle (4) is a primary main circuit electronic expansion valve, and the fan (6) is a DC brushless fan.

4. The cascade high temperature heat pump system according to claim 1, characterized in that: An intermediate heat exchanger (10) is provided between the primary heat pump system and the secondary heat pump system. The first refrigerant inlet and the first refrigerant outlet of the intermediate heat exchanger (10) are respectively connected to the refrigerant outlet end of the four-way valve (2) and the refrigerant inlet of the primary heat exchanger (3). The second refrigerant inlet and the second refrigerant outlet of the intermediate heat exchanger (10) are respectively connected to the refrigerant outlet of the secondary economizer and the refrigerant inlet end of the secondary heat pump system.

5. The cascade high temperature heat pump system according to claim 4, characterized in that: The two-stage heat pump system comprises a two-stage compressor (11), a two-stage water-side heat exchanger (12), and a two-stage throttle (13); the two-stage compressor (11), the two-stage water-side heat exchanger (12), the two-stage throttle (13), and the intermediate heat exchanger (10) are connected via pipelines to form a main circulation path for a two-stage refrigerant.

6. The cascade high temperature heat pump system according to claim 5, characterized in that: The secondary compressor (11) is configured as a fixed-frequency compressor; and the secondary throttle (13) is configured as a secondary electronic expansion valve.

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