CN202267274U - Ultralow-temperature air source heat pump - Google Patents

Abstract

The utility model discloses an ultralow-temperature air source heat pump, and belongs to the field of heat pumps. The ultralow-temperature air source heat pump consists of a compressor, a four-way valve, a first heat exchanger, an economizer, an electronic expansion valve, an electromagnetic two-way valve, a thermal expansion valve, a second heat exchanger and a gas-liquid separator, wherein the exhaust port of the compressor is connected with the port D of the four-way valve, and the port C of the four-way valve is connected with the refrigerant inlet of the first heat exchanger; the refrigerant outlet of the first heat exchanger is connected to the inlet of the electronic expansion valve, and the outlet of the electronic expansion valve 5 is connected to the enthalpy rising inlet of the economizer; the refrigerant outlet of the first heat exchanger is connected with the under-cooling inlet of the economizer; the outlet of the thermal expansion valve is connected with the inlet of the second heat exchanger; the outlet of the gas-liquid separator is connected with the air return port of the compressor; a one-way valve is connected to one end of the thermal expansion valve; the one-way valve is connected with a capillary tube; and the capillary tube is connected with the other end of the thermal expansion valve. The heat pump saves the cost, is stable in a system, and has good heating and refrigerating effects.

Description

Ultra-low temperature air source heat pump

Technical Fields

The utility model relates to an ultra-low temperature air source heat pump belonging to the field of heat pumps, in particular to an ultra-low temperature air source heat pump capable of working in an ultra-low temperature environment.

Background technique

The air source heat pump consists of a compressor, a four-way valve, a first heat exchanger, an economizer, an electronic expansion valve, an electromagnetic two-way valve, a thermal expansion valve, a second heat exchanger, and a gas-liquid separator. The gas port is connected to port D of the four-way valve, port C of the four-way valve is connected to the refrigerant inlet of the first heat exchanger, the refrigerant outlet of the first heat exchanger is connected to the inlet of the electronic expansion valve, and the outlet of the electronic expansion valve is connected to the economizer The enthalpy inlet of the economizer, the enthalpy outlet of the economizer is connected with the auxiliary air inlet of the compressor, the subcooling outlet of the economizer is connected with the inlet of the electromagnetic two-way valve, and the outlet of the electromagnetic two-way valve is connected with the auxiliary air inlet of the compressor , the refrigerant outlet of the first heat exchanger is connected to the subcooling inlet of the economizer, the subcooling outlet of the economizer is connected to the inlet of the thermal expansion valve, the outlet of the thermal expansion valve is connected to the inlet of the second heat exchanger, and the second heat exchanger The outlet of the heater is connected to the E port of the four-way valve, the S port of the four-way valve is connected to the inlet of the gas-liquid separator, and the outlet of the gas-liquid separator is connected to the air return port of the compressor.

The air injection enthalpy increasing technology has been applied to a certain extent in the heat pump industry. At present, the ultra-low temperature air source heat pump adopting the air injection enthalpy increasing technology can realize low-temperature heating. Heating capacity in severe cold environments. Ordinary gas injection enthalpy increasing systems usually set a thermal expansion valve as a throttling device between the economizer (also known as the subcooler) and the evaporator. However, how to choose a thermal expansion valve with a suitable cooling tonnage has become a technical problem: if a thermal expansion valve with a small cooling tonnage is used, the heating condition will be relatively ideal, but when the heat pump unit is switched to cooling, the cooling of the thermal expansion valve will The tonnage is too small, which makes the flow through the throttling device of the system too small, thus affecting the cooling capacity of the unit; if a thermal expansion valve with a large cooling tonnage is used, the cooling condition of the heat pump unit is relatively ideal, but the cost is high , and when the heat pump unit is heating in an ultra-low temperature environment, there are obvious defects. Due to the large cooling tonnage, the opening degree of the thermal expansion valve is not easy to grasp, which may cause too much refrigerant to flow to the evaporator. Under normal circumstances, the evaporation of the refrigerant is relatively small, resulting in insufficient evaporation of the refrigerant, and the compressor is prone to liquid hammering, the heating effect of the entire system is poor, and the service life of the compressor is affected.

Utility model content

The purpose of the utility model is to avoid the deficiencies of the prior art, and provide an ultra-low temperature air source heat pump with cost saving, stable system, and good heating and cooling effects.

The purpose of this utility model is achieved through the following measures. The ultra-low temperature air source heat pump includes a compressor, a four-way valve, a first heat exchanger, an economizer, an electronic expansion valve, an electromagnetic two-way valve, a thermal expansion valve, a second Composed of a heat exchanger and a gas-liquid separator, the exhaust port of the compressor is connected to the port D of the four-way valve, the port C of the four-way valve is connected to the refrigerant inlet of the first heat exchanger, and the refrigerant outlet of the first heat exchanger is connected to To the inlet of the electronic expansion valve, the outlet of the electronic expansion valve is connected to the enthalpy inlet of the economizer, the enthalpy outlet of the economizer is connected to the auxiliary air inlet of the compressor, the subcooling outlet of the economizer is connected to the inlet of the electromagnetic two-way valve, and the solenoid The outlet of the two-way valve is connected with the auxiliary air inlet of the compressor, the refrigerant outlet of the first heat exchanger is connected with the subcooling inlet of the economizer, the subcooling outlet of the economizer is connected with the inlet of the thermal expansion valve, and the The outlet is connected to the inlet of the second heat exchanger, the outlet of the second heat exchanger is connected to the E port of the four-way valve, the S port of the four-way valve is connected to the inlet of the gas-liquid separator, and the outlet of the gas-liquid separator is connected to the compressor The air return port of the machine is connected,

One end of the thermal expansion valve is connected with a one-way valve, the one-way valve is connected with a capillary, and the capillary is connected with the other end of the thermal expansion valve.

The first heat exchanger of the utility model is a refrigerant-water heat exchanger, and the second heat exchanger is a refrigerant-air heat exchanger.

The thermal expansion valve is connected in parallel with the one-way valve and the capillary tube. When heating, the refrigerant cannot flow through the branch of the capillary tube, which effectively prevents the insufficient evaporation of the refrigerant and the occurrence of liquid hammer in the compressor. At the same time, because Choosing a thermal expansion valve with a relatively small cooling tonnage can effectively save costs and have a good heating effect. In the refrigeration cycle, the refrigerant flows through the branch circuit of the thermal expansion valve and the branch circuit composed of the capillary tube and the one-way valve. The amount of refrigerant entering the first heat exchanger per unit time is sufficient, so that the refrigerant is The first heat exchanger is fully evaporated, the cooling capacity of the unit is fully utilized, and the cooling effect is good.

The utility model saves cost, has stable system, and has good heating and cooling effects.

Description of drawings

Accompanying drawing 1 is the connection structure schematic diagram of the embodiment of the present utility model.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described.

In the figure: compressor 1, four-way valve 2, first heat exchanger 3, economizer 4, electronic expansion valve 5, electromagnetic two-way valve 6, thermal expansion valve 7, one-way valve 8, capillary tube 9, second heat exchanger Heater 10, gas-liquid separator 11.

As shown in Figure 1, the utility model includes a compressor 1, a four-way valve 2, a first heat exchanger 3, an economizer 4, an electronic expansion valve 5, an electromagnetic two-way valve 6, a thermal expansion valve 7, a one-way Valve 8, capillary tube 9, second heat exchanger 10, gas-liquid separator 11 constitute. The exhaust port of the compressor 1 is connected to the port D of the four-way valve 2, the port C of the four-way valve 2 is connected to the refrigerant inlet of the first heat exchanger 3, and the refrigerant outlet of the first heat exchanger 3 is connected to the electronic expansion valve 5 inlet, the outlet of the electronic expansion valve 5 is connected to the enthalpy inlet of the economizer 4, the enthalpy outlet of the economizer 4 is connected to the auxiliary air inlet of the compressor 1, and the subcooling outlet of the economizer 4 is connected to the electromagnetic two-way valve 6 The inlet is connected, the outlet of the electromagnetic two-way valve 6 is connected to the auxiliary air inlet of the compressor 1, the refrigerant outlet of the first heat exchanger 3 is connected to the subcooling inlet of the economizer 4, and the subcooling outlet of the economizer 4 is connected to the thermal expansion The inlet of valve 7 is connected, the outlet of thermal expansion valve 7 is connected with the inlet of second heat exchanger 10, one end of thermal expansion valve 7 is connected with check valve 8, check valve 8 is connected with capillary 9, and capillary 9 is connected with thermal expansion valve 7 at the other end. A capillary 9 and a one-way valve 8 are arranged in parallel at the inlet and outlet of the thermal expansion valve 7 , the one-way valve 8 is connected in series with the capillary 9 , and the inlet of the one-way valve 8 is connected with the capillary 9 . The outlet of the second heat exchanger 10 is connected with the E port of the four-way valve 2 . The S port of the four-way valve 2 is connected with the inlet of the gas-liquid separator 11 , and the outlet of the gas-liquid separator 11 is connected with the gas return port of the compressor 1 . The first heat exchanger is a refrigerant-water heat exchanger, and the second heat exchanger is a refrigerant-air heat exchanger.

working principle;

a. Heating: The compressor 1 works to discharge high-temperature and high-pressure refrigerant gas. The refrigerant gas flows in from the D port of the four-way valve 2, flows out from the C port of the four-way valve 2, and enters the first heat exchanger 3. , the refrigerant gas becomes liquid after being condensed by the first heat exchanger 3, and the high-pressure refrigerant liquid flowing out from the first heat exchanger 3 flows in two paths, one path is the main loop, and the other path is the auxiliary loop. The refrigerant liquid in the main circuit enters the economizer 4, and the refrigerant liquid in the auxiliary circuit is depressurized by the electronic expansion valve 8 to become a low-pressure gas-liquid mixture, and also enters the economizer 4 at the same time, and the two refrigerants enter the economizer 4 After the heat exchange occurs, the refrigerant in the auxiliary circuit absorbs heat and turns into a gas, which is sucked by the auxiliary air inlet of the compressor 1 . The refrigerant in the main path flows out from the subcooling outlet of the economizer 4 , becomes a subcooled liquid, and flows into the second heat exchanger 10 after being depressurized by the thermal expansion valve 7 . (Because there is a single-phase valve in the branch of the capillary, the refrigerant cannot flow through the branch of the capillary when heating)

The refrigerant liquid absorbs the heat of the surrounding air in the second heat exchanger 10 to evaporate, and the refrigerant gas after evaporation passes through the E port and S port of the four-way valve in turn, enters the gas-liquid separator 11, and is separated from the gas-liquid The device 11 flows out, returns to the compressor from the air return port of the compressor, and completes the heating cycle. The electromagnetic two-way valve is opened and closed according to actual needs. The system selects a thermal expansion valve with a relatively small cooling ton value. After the refrigerant flows through the thermal expansion valve, the amount of refrigerant entering the second heat exchanger per unit time is relatively small, so that the refrigerant can be completely evaporated. It effectively prevents the phenomenon of insufficient refrigerant evaporation and liquid hammer of the compressor. At the same time, because the thermal expansion valve with a relatively small cooling tonnage is selected, the cost is effectively saved, and the heating effect is good.

b. Refrigeration: The compressor 1 works to discharge high-temperature and high-pressure refrigerant gas. The refrigerant gas flows in from the D port of the four-way valve 2, flows out from the E port of the four-way valve 2, and enters the second heat exchanger 10. The refrigerant gas becomes liquid after being condensed by the second heat exchanger 10, and the high-pressure refrigerant liquid flowing out from the second heat exchanger 10 flows in two paths, one path passes through the thermal expansion valve 7, and the other path passes through the capillary tube 9 and the one-way valve 8. Then the two paths of refrigerant converge into one path and enter the economizer 4. After the refrigerant flows out of the economizer 4, it enters the first heat exchanger 3, and the refrigerant passes through the first heat exchanger 3 after being completely evaporated. The ports C and S of the four-way valve enter the gas-liquid separator 11, then flow out from the gas-liquid separator 11, and return to the compressor from the air return port of the compressor to complete the refrigeration cycle. Although the cooling ton value of the thermal expansion valve selected by the system is relatively small, the refrigerant flows through both the branch of the thermal expansion valve and the branch composed of the capillary and the check valve, so the refrigerant enters the first The amount of refrigerant in the heat exchanger is sufficient so that the refrigerant is fully evaporated at the first heat exchanger. The cooling capacity of the unit has been fully utilized, and the cooling effect is good.

Claims (2)

1. An ultra-low temperature air source heat pump, including a compressor, a four-way valve, a first heat exchanger, an economizer, an electronic expansion valve, an electromagnetic two-way valve, a thermal expansion valve, a second heat exchanger, and a gas-liquid separator The exhaust port of the compressor is connected to the port D of the four-way valve, the port C of the four-way valve is connected to the refrigerant inlet of the first heat exchanger, the refrigerant outlet of the first heat exchanger is connected to the inlet of the electronic expansion valve, and the electronic expansion valve The outlet of valve 5 is connected to the enthalpy inlet of the economizer, the enthalpy outlet of the economizer is connected to the auxiliary air inlet of the compressor, the subcooling outlet of the economizer is connected to the inlet of the electromagnetic two-way valve, and the outlet of the electromagnetic two-way valve is connected to the compressor The refrigerant outlet of the first heat exchanger is connected with the subcooling inlet of the economizer, the subcooling outlet of the economizer is connected with the inlet of the thermal expansion valve, and the outlet of the thermal expansion valve is connected with the second heat exchanger The inlet of the second heat exchanger is connected to the E port of the four-way valve, the S port of the four-way valve is connected to the inlet of the gas-liquid separator, and the outlet of the gas-liquid separator is connected to the air return port of the compressor. The feature is that one end of the thermal expansion valve is connected with a check valve, the check valve is connected with a capillary, and the capillary is connected with the other end of the thermal expansion valve. 2. The ultra-low temperature air source heat pump according to claim 1, characterized in that the first heat exchanger is a refrigerant-water heat exchanger, and the second heat exchanger is a refrigerant-air heat exchanger.

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