Normal-temperature heat pump water heater unit

Abstract

The application relates to a normal-temperature heat pump hot water unit, which comprises a main refrigerant circuit and a supplement circuit. The main refrigerant circuit comprises a compressor, a four-way reversing valve, a water circuit heat exchanger, a first throttling device and a fin heat exchanger. The supplement circuit comprises a compressor, a four-way reversing valve, a water circuit heat exchanger, a control valve and a flash evaporator. The unit is provided with the supplement circuit between the water circuit heat exchanger and the first throttling device, and the control valve and the flash evaporator are arranged on the supplement circuit. The gaseous refrigerant emitted by the flash evaporator is supplemented to the suction port of the compressor, the suction amount of the compressor is increased, the heating capacity of the normal-temperature heat pump hot water unit is obviously improved, the operation lower limit of the traditional normal-temperature compressor is broken, the lowest ring temperature for stable operation of the unit is further reduced, and the unit is more suitable for high-cold areas.

Description

Technical Field

[0001] This application relates to the field of heat exchange equipment technology, specifically to a normal temperature heat pump water heater unit. Background Technology

[0002] Ambient temperature heat pump water heaters are energy-saving devices that are based on the principle of vapor compression heat pump cycle. They use the ambient temperature as a low-grade heat source and achieve heat transfer through refrigerant phase change, efficiently producing domestic or industrial hot water. They are widely used in hot water supply scenarios such as residential buildings, commercial buildings, and industrial production.

[0003] However, the ambient temperature compressors used in traditional ambient temperature heat pump water heaters are limited by their design, typically operating in environments ranging from -7°C to 45°C. When the ambient temperature drops below -7°C, the compressor's suction capacity decreases significantly, resulting in a substantial reduction in heating output. This makes it impossible to meet the water supply demands of the unit in low-temperature environments, hindering its use in extremely cold regions. Furthermore, under low-temperature conditions, the reduced suction capacity of the compressor causes a sharp increase in exhaust temperature, exceeding the equipment's safe operating threshold. This leads to overheating and damage to core components such as compressor valves and cylinders, affecting not only the unit's stable operation but also shortening the compressor's lifespan. Utility Model Content

[0004] To overcome the shortcomings of existing technologies, this application provides a normal temperature heat pump water heater unit, specifically adopting the following technical solution: A normal temperature heat pump water heater unit includes a main refrigerant circuit and a gas makeup circuit. The main refrigerant circuit includes a compressor, a four-way reversing valve, a water heat exchanger, a first throttling element, and a finned heat exchanger; while the make-up gas circuit includes a compressor, a four-way reversing valve, a water heat exchanger, a control valve, and a flash evaporator. The compressor's discharge port is connected to the refrigerant inlet of the water heat exchanger via a four-way reversing valve, and the refrigerant outlet of the water heat exchanger is connected to the inlet of the first throttling element and the inlet of the control valve, respectively. The outlet of the first throttling element is connected to one end of the finned heat exchanger, and the other end of the finned heat exchanger is connected to the suction port of the compressor via a four-way reversing valve. The outlet of the control valve is connected to the refrigerant inlet of the flash evaporator, and the steam outlet of the flash evaporator is connected to the suction port of the compressor.

[0005] Optional: A second throttling element is provided between the outlet of the control valve and the refrigerant inlet of the flash evaporator. The second throttling element is used to control the amount of refrigerant supplied to the flash evaporator.

[0006] Optionally, the control valve is preferably a solenoid valve, which can control the on / off state of the gas supply circuit. The second throttling element is preferably a one-way throttling valve, with the refrigerant flow direction of the second throttling element towards the refrigerant inlet of the flash evaporator.

[0007] Furthermore, the first throttling element is preferably an electronic expansion valve.

[0008] Optional: The second throttling element is preferably a capillary tube. The control valve is preferably a one-way solenoid valve, and the refrigerant flow direction of the control valve is towards the refrigerant inlet of the flash evaporator.

[0009] Optional: When the control valve remains closed, the main refrigerant circuit is activated, while the gas supply circuit remains deactivated.

[0010] Optional: When the control valve remains open, both the main refrigerant circuit and the make-up gas circuit are activated.

[0011] Optional: A gas-liquid separator is provided between the steam outlet of the flash evaporator and the suction port of the compressor. The gas-liquid separator is used to separate the liquid components in the steam refrigerant. The inlet of the gas-liquid separator is connected to the steam outlet of the flash evaporator, and the outlet of the gas-liquid separator is connected to the suction port of the compressor.

[0012] The technical solution of this application achieves the following beneficial effects: The ambient temperature heat pump water heater unit of this application adds an intake circuit between the water circuit heat exchanger and the first throttling element, and uses the gaseous refrigerant flashed by the flash evaporator to supplement the intake port of the compressor, thereby increasing the intake volume of the compressor and significantly improving the heating capacity of the ambient temperature heat pump water heater unit. This breaks through the lower operating limit of traditional ambient temperature compressors, further reducing the minimum ambient temperature for stable operation of the unit, making it more suitable for high-altitude and cold regions. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the heating process of a room temperature heat pump water heater unit in an embodiment of this application.

[0014] The specific meanings of the reference numerals in the attached figures: 1-Compressor; 2-Four-way reversing valve; 3-Water heat exchanger; 4-First throttling element; 5-Finned heat exchanger; 6-Control valve; 7-Second throttling element; 8-Flash evaporator. Detailed Implementation

[0015] The present application will now be further described with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application and should not be construed as limiting the scope of protection of the present application. It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present application.

[0016] Example 1: This embodiment 1 specifically discloses a normal temperature heat pump water heater unit, which includes a main refrigerant circuit and a gas supply circuit. Specifically, such as Figure 1As shown, the main refrigerant circuit of this embodiment 1 includes a compressor 1, a four-way reversing valve 2, a water heat exchanger 3, a first throttling element 4, and a finned heat exchanger 5. The first throttling element 4 is preferably an electronic expansion valve, which can adjust its opening in real time according to the operating parameters of the main refrigerant circuit, precisely controlling the refrigerant flow rate entering the finned heat exchanger 5 in the main refrigerant circuit to adapt to different heating load requirements and improve system energy efficiency.

[0017] In the main refrigerant circuit, the exhaust port of compressor 1 is connected to the refrigerant inlet of water heat exchanger 3 via a four-way reversing valve. The refrigerant outlet of water heat exchanger 3 is connected to the inlet of the first throttling element 4, and the outlet of the first throttling element 4 is connected to one end of finned heat exchanger 5. The other end of finned heat exchanger 5 is connected to the suction port of compressor 1 via a four-way reversing valve.

[0018] More specifically, such as Figure 1 As shown, the gas replenishment circuit of this embodiment 1 includes a compressor 1, a four-way reversing valve 2, a water heat exchanger 3, a control valve 6, and a flash evaporator 8. In the gas replenishment circuit, the exhaust port of the compressor 1 is connected to the refrigerant inlet of the water heat exchanger 3 via the four-way reversing valve. The refrigerant outlet of the water heat exchanger 3 is connected to the inlet of the control valve 6. The outlet of the control valve 6 is connected to the refrigerant inlet of the flash evaporator 8. The steam outlet of the flash evaporator 8 is connected to the suction port of the compressor 1. To throttle and reduce the pressure of the refrigerant entering the flash evaporator 8, this embodiment 1 provides a second throttling element 7 between the outlet of the control valve 6 and the refrigerant inlet of the flash evaporator 8. The amount of refrigerant entering the flash evaporator 8 can be controlled by adjusting the opening of the second throttling element 7.

[0019] As a preferred embodiment, in this example 1, the control valve 6 preferably uses a solenoid valve as the main switch for the gas replenishment circuit. Through rapid response to electromagnetic signals, it achieves on / off control of the gas replenishment circuit, precisely adjusting the circuit's operating status in accordance with changes in unit load. The second throttling element 7 preferably uses a one-way throttling valve. On one hand, it can throttle and reduce the pressure of the refrigerant entering the flash evaporator 8, converting part of the refrigerant into a gas-liquid two-phase state. On the other hand, it can utilize its one-way conduction characteristic to prevent the refrigerant in the flash evaporator 8 from flowing back to the water heat exchanger 3, avoiding affecting the stability of the main circuit refrigerant parameters. Simultaneously, it precisely controls the amount of refrigerant entering the flash evaporator 8, ensuring that the flash evaporator 8 efficiently generates saturated steam.

[0020] In detail, in this embodiment 1, when the ambient temperature heat pump water heater is operating at low load (i.e., the ambient temperature is ≥0℃), the solenoid valve remains closed, the gas supply circuit is shut down, and only the main refrigerant circuit is operational. At this time, the high-temperature, high-pressure refrigerant discharged from the compressor 1 enters the water circuit heat exchanger 3 through the four-way reversing valve 2. The refrigerant exchanges heat with the cold water in the water circuit heat exchanger 3. After the refrigerant condenses and releases heat, it is throttled and depressurized through the electronic expansion valve, becoming a low-temperature, low-pressure gas-liquid mixture that enters the finned heat exchanger 5. There, it absorbs heat from the air and evaporates into a gaseous state, then returns to the compressor 1's suction port through the four-way reversing valve 2, completing the main refrigerant circuit cycle.

[0021] When the ambient temperature heat pump water heater is operating under high load (i.e., ambient temperature < 0℃), the solenoid valve remains open, and the gas replenishment circuit operates simultaneously with the main circuit. At this time, the high-temperature, high-pressure refrigerant discharged from compressor 1 enters the water heat exchanger 3 via the four-way reversing valve 2. The refrigerant exchanges heat with cold water in the water heat exchanger 3. Subsequently, most of the refrigerant flowing out of the water heat exchanger 3's outlet is throttled and depressurized by the electronic expansion valve, becoming a low-temperature, low-pressure gas-liquid mixture that enters the finned heat exchanger 5 to participate in the main refrigerant circuit circulation. A portion of the refrigerant flowing out of the water heat exchanger 3's outlet enters the one-way throttle valve via the solenoid valve, and then enters the flash evaporator 8 for gas-liquid separation. The separated saturated steam enters the compressor 1's suction port from the flash evaporator 8's steam outlet, replenishing the compressor 1 and improving its gas delivery coefficient and heating capacity. At this time, the main refrigerant circuit operates normally, and the gas replenishment circuit works synergistically to improve the unit's heating capacity and operating efficiency.

[0022] Example 2: This embodiment 2 also discloses a normal temperature heat pump water heater unit, which includes a main refrigerant circuit and a gas makeup circuit. Compared with the normal temperature heat pump water heater unit of embodiment 1, in this embodiment 2, the control valve 6 preferably adopts a one-way solenoid valve as the main switch of the gas makeup circuit, which has both on / off control and one-way flow guidance functions. When energized, the control valve 6 opens, allowing the refrigerant to flow from the water circuit heat exchanger 3 to the flash evaporator 8; when de-energized, the control valve 6 closes, cutting off the gas makeup circuit. At the same time, its one-way characteristic can prevent the refrigerant in the flash evaporator 8 from flowing back into the water circuit heat exchanger 3, avoiding refrigerant pressure fluctuations in the main refrigerant circuit and ensuring system stability.

[0023] The second throttling element 7 is preferably a capillary tube, which utilizes its small inner diameter and fixed length to throttle and reduce the pressure of the refrigerant. The throttling effect of this capillary tube can be determined according to the tube diameter and length. It has a simple structure, low cost, and does not require electrical control, making it suitable for scenarios with relatively gentle load changes.

[0024] In detail, in this embodiment 2, when the ambient temperature heat pump water heater is operating at low load (i.e., the ambient temperature is ≥0℃), the one-way solenoid valve remains closed, the gas replenishment circuit is shut down, and only the main refrigerant circuit is operational. At this time, the high-temperature and high-pressure refrigerant discharged from the compressor 1 enters the water circuit heat exchanger 3 through the four-way reversing valve 2. The refrigerant exchanges heat with the cold water in the water circuit heat exchanger 3. After the refrigerant condenses and releases heat, it is throttled and depressurized through the electronic expansion valve, becoming a low-temperature and low-pressure gas-liquid mixture that enters the finned heat exchanger 5. It absorbs heat from the air and evaporates into a gaseous state, then returns to the compressor 1's suction port through the four-way reversing valve 2, completing the main refrigerant circuit cycle.

[0025] When the ambient temperature heat pump water heater is operating under high load (i.e., ambient temperature < 0℃), the one-way solenoid valve remains open, and the gas replenishment circuit operates simultaneously with the main circuit. At this time, the high-temperature, high-pressure refrigerant discharged from compressor 1 enters the water heat exchanger 3 via the four-way reversing valve 2. The refrigerant exchanges heat with cold water in the water heat exchanger 3. Subsequently, most of the refrigerant flowing out of the water heat exchanger 3's outlet is throttled and depressurized by the electronic expansion valve, becoming a low-temperature, low-pressure gas-liquid mixture that enters the finned heat exchanger 5 to participate in the main refrigerant circuit circulation. Meanwhile, a portion of the refrigerant flowing out of the water heat exchanger 3's outlet enters the capillary tube via the one-way solenoid valve, and then enters the flash evaporator 8 for gas-liquid separation. The separated saturated steam enters the compressor 1's suction port from the flash evaporator 8's steam outlet, replenishing the compressor 1 and improving its gas delivery coefficient and heating capacity. At this time, the main refrigerant circuit operates normally, and the gas replenishment circuit works synergistically to improve the unit's heating capacity and operating efficiency.

[0026] Example 3: This embodiment 3 also discloses a normal temperature heat pump water heater unit. Compared with the structure of embodiment 1, this embodiment 3 adds a gas-liquid separator in the gas replenishment circuit to further improve the dryness of the refrigerant entering the compressor 1, protect the compressor 1 from liquid slugging damage, and extend the service life of the unit.

[0027] Specifically, in this embodiment 3, a gas-liquid separator is provided between the steam outlet of the flash evaporator 8 and the suction port of the compressor 1. The gas-liquid separator performs secondary gas-liquid separation on the steam refrigerant discharged from the flash evaporator 8.

[0028] In one embodiment, the gas-liquid separator can be integrated into the suction port of the compressor 1, and the liquid refrigerant collected by the gas-liquid separator can be collected into the compressor; or the gas-liquid separator can be integrated into the steam outlet of the flash evaporator 8, and the liquid refrigerant collected by the gas-liquid separator can flow back to the bottom of the flash evaporator 8. In another embodiment, the gas-liquid separator can also be installed on the connecting pipe between the steam outlet of the flash evaporator 8 and the suction port of the compressor 1.

[0029] Because the separation effect of flash evaporator 8 may be affected by factors such as load fluctuations and refrigerant flow rate, some liquid refrigerant may enter the suction port of compressor 1 with the steam, causing liquid slugging in compressor 1. The gas-liquid separator separates the liquid refrigerant from the steam through principles such as gravity settling and centrifugal separation, allowing only dry gaseous refrigerant to enter compressor 1, effectively protecting the cylinders, valves and other components of compressor 1, and improving the reliability of unit operation.

[0030] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A normal temperature heat pump water heater unit, characterized in that, Including the main refrigerant circuit and the make-up gas circuit, The main refrigerant circuit includes a compressor, a four-way reversing valve, a water heat exchanger, a first throttling element, and a finned heat exchanger; the make-up gas circuit includes a compressor, a four-way reversing valve, a water heat exchanger, a control valve, and a flash evaporator. The compressor's exhaust port is connected to the refrigerant inlet of the water heat exchanger via the four-way reversing valve, and the refrigerant outlet of the water heat exchanger is connected to the inlet of the first throttling element and the inlet of the control valve, respectively. The outlet of the first throttling element is connected to one end of the finned heat exchanger, and the other end of the finned heat exchanger is connected to the suction port of the compressor via the four-way reversing valve. The outlet of the control valve is connected to the refrigerant inlet of the flash evaporator, and the steam outlet of the flash evaporator is connected to the suction port of the compressor.

2. The ambient temperature heat pump water heater unit according to claim 1, characterized in that, A second throttling element is provided between the outlet of the control valve and the refrigerant inlet of the flash evaporator. The second throttling element is used to control the amount of refrigerant entering the flash evaporator.

3. The ambient temperature heat pump water heater unit according to claim 2, characterized in that, The control valve is a solenoid valve.

4. The ambient temperature heat pump water heater unit according to claim 3, characterized in that, The second throttling element is a one-way throttling valve, and the refrigerant flow direction of the second throttling element is towards the refrigerant inlet of the flash evaporator.

5. The ambient temperature heat pump water heater unit according to claim 1, characterized in that, The first throttling element is an electronic expansion valve.

6. The ambient temperature heat pump water heater unit according to claim 2, characterized in that, The second throttling element is a capillary tube.

7. The ambient temperature heat pump water heater unit according to claim 6, characterized in that, The control valve is a one-way solenoid valve, and the refrigerant flow direction of the control valve is towards the refrigerant inlet of the flash evaporator.

8. The ambient temperature heat pump water heater unit according to claim 1, characterized in that, When the control valve remains closed, the main refrigerant circuit remains open, and the gas supply circuit remains closed.

9. The ambient temperature heat pump water heater unit according to claim 1, characterized in that, When the control valve remains open, both the main refrigerant circuit and the gas supply circuit remain connected.

10. The ambient temperature heat pump water heater unit according to claim 1, characterized in that, A gas-liquid separator is provided between the steam outlet of the flash evaporator and the suction port of the compressor. The gas-liquid separator is used to separate the liquid components in the steam refrigerant. The inlet of the gas-liquid separator is connected to the steam outlet of the flash evaporator, and the outlet of the gas-liquid separator is connected to the suction port of the compressor.

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