Internal circulation module and heat pump

Abstract

The utility model discloses an internal circulation module and a heat pump, and the internal circulation module comprises a compressor which is provided with an air return port, an exhaust port and an enthalpy increasing port; a refrigerant inlet of the heat exchanger is communicated with the exhaust port, a refrigerant outlet of the heat exchanger is connected with a first branch and a second branch, and the first branch is sequentially provided with an air supply switch valve and an air supply capillary tube; the economizer is provided with a first inlet and a first outlet which are communicated with each other and a second inlet and a second outlet which are communicated with each other, the second branch is connected to the first inlet, the first outlet is connected with a third branch and a fourth branch, the third branch is provided with a main electronic expansion valve, the fourth branch is provided with an auxiliary electronic expansion valve, and the fourth branch is connected to the second inlet; the second outlet is communicated with the enthalpy increasing opening; the evaporator is provided with an inflow port and an outflow port, and the third branch is connected to the inflow port; the gas-liquid separator is connected with an inlet pipeline and an outlet pipeline, the inlet pipeline is communicated with the outflow port, the first branch is communicated with the inlet pipeline, and the outlet pipeline is connected to the gas return port. The technology can keep normal work in low-cold areas.

Description

Technical Field

[0001] The utility model relates to the technical field of heat pumps, in particular to an internal circulation module and a heat pump. Background Art

[0002] The internal circulation module of a heat pump typically includes a compressor, heat exchanger, liquid storage tank, filter, expansion valve, evaporator, and gas-liquid separator. The compressor heats and pressurizes the gaseous refrigerant, turning it into a high-temperature, high-pressure gaseous refrigerant. After passing through the heat exchanger, the high-temperature, high-pressure gaseous refrigerant exchanges heat with the medium outside the heat exchanger, heating the medium. After this heat exchange, the refrigerant becomes a normal-temperature, high-pressure liquid refrigerant. This high-pressure, normal-temperature liquid refrigerant then passes through the liquid storage tank and filter before reaching the expansion valve. The expansion valve, with its capillary tubes several meters long, converts the normal-temperature, high-pressure liquid refrigerant into a low-temperature, low-pressure liquid refrigerant. Because the refrigerant's temperature is lower than the ambient temperature, the low-temperature, low-pressure liquid refrigerant absorbs heat from the ambient temperature after passing through the evaporator, transforming it into a normal-temperature, low-pressure gaseous refrigerant. The gaseous refrigerant is filtered out by the gas-liquid separator, removing any unvaporized refrigerant, ensuring that the compressor receives gaseous refrigerant from the suction port for the internal circulation of the refrigerant.

[0003] However, if the ambient temperature is close to the temperature of the refrigerant flowing out of the expansion valve, the low-temperature and low-pressure liquid refrigerant will find it difficult to obtain enough heat from the ambient temperature. At this time, the refrigerant returning to the compressor fails to be fully vaporized, causing the gaseous refrigerant in the internal circulation module to become less and less, and eventually causing the compressor to shut down due to insufficient gaseous refrigerant.

[0004] To this end, it is urgent to improve the working conditions of heat pumps in low-cold areas to expand the application scenarios of heat pumps and increase the market share of heat pumps. Utility Model Content

[0005] The utility model aims to provide an internal circulation module, which can maintain normal operation in a low-temperature environment.

[0006] According to the first embodiment of the present invention, the internal circulation module comprises:

[0007] A compressor, comprising an air return port, an air discharge port, an enthalpy increase port, and a cylinder body, wherein the cylinder body takes in air from the air return port and / or the enthalpy increase port, and exhausts air to the air discharge port;

[0008] A heat exchanger having a refrigerant inlet and a refrigerant outlet, wherein the refrigerant inlet is connected to the exhaust port, and the refrigerant outlet is connected to a three-way pipe a, wherein the three-way pipe a includes a first branch and a second branch, wherein the first branch is sequentially provided with an air supply switch valve and an air supply capillary tube, and the second branch is sequentially provided with a liquid storage tank and a filter;

[0009] An economizer having a first inlet and a first outlet that are interconnected, and a second inlet and a second outlet that are interconnected, the second branch being connected to the first inlet, the first outlet being connected to a three-way pipe b, the three-way pipe b including a third branch and a fourth branch, the third branch being provided with a main electronic expansion valve, the fourth branch being provided with a secondary electronic expansion valve, the fourth branch being connected to the second inlet, and the second outlet being connected to the enthalpy increase port;

[0010] an evaporator having an inlet and an outlet, wherein the third branch is connected to the inlet;

[0011] The gas-liquid separator is connected to an inlet pipeline and an outlet pipeline, the inlet pipeline is communicated with the outflow port, the first branch is communicated with the inlet pipeline, and the outlet pipeline is connected to the gas return port.

[0012] According to the internal circulation module of the embodiment of the present invention, there are at least the following beneficial effects: the refrigerant main circuit of the economizer flows from the first inlet to the first outlet, and the refrigerant secondary circuit of the economizer flows from the second inlet to the second outlet. When the ambient temperature is lower than the set value, the secondary electronic expansion valve of the fourth branch starts, and the refrigerant flowing out of the first outlet of the economizer flows through the third branch and the fourth branch respectively. The refrigerant in the third branch flows through the main electronic expansion valve, the evaporator and the gas-liquid separator according to the existing path. However, due to the low ambient temperature, the compressor cannot obtain enough gaseous refrigerant from the gas-liquid separator, and the refrigerant in the fourth branch is converted into a low-temperature and low-pressure liquid refrigerant after flowing through the secondary electronic expansion valve. The refrigerant exchanges heat with the refrigerant main circuit of the economizer, flows into the compressor from the enthalpy increase port, is sucked into the middle injection port of the compressor, and is mixed with the refrigerant in the main circuit to produce an enthalpy increase effect, thereby increasing the heating capacity; since the opening of the secondary electronic expansion valve is adjusted according to the ambient temperature When the opening of the auxiliary electronic expansion valve is small, the gaseous refrigerant in the compressor will become less and less, resulting in an increase in the exhaust temperature of the compressor. In order to suppress the increase in exhaust temperature, when the exhaust temperature of the compressor is higher than a predetermined value, the air supply switch valve on the first branch is opened, and the refrigerant flowing out of the refrigerant outlet of the heat exchanger flows through the first branch and the second branch respectively. The refrigerant in the second branch flows through the liquid storage tank and the filter according to the existing path and flows into the economizer, while the refrigerant in the first branch is transported to the front of the air-liquid separator after being reduced in pressure and cooled by the air supply capillary. The gaseous refrigerant is then returned to the compressor by the gas-liquid separator, and the exhaust temperature of the compressor is reduced by lowering the return air temperature, and a certain amount of gaseous refrigerant is added to the compressor to avoid cylinder jamming due to excessively high exhaust temperature. Compared with the existing technology, the utility model can maintain normal operation in low-cold areas, effectively expand the applicable areas of heat pumps, and has good market prospects.

[0013] According to some embodiments of the present invention, the internal circulation module further includes a four-way valve, which is respectively connected to the compression line, the heat exchange line, the evaporation line, and the outlet line. The compression line is connected to the exhaust port, the heat exchange line is connected to the refrigerant inlet, and the evaporation line is connected to the outflow port. During heating, the four-way valve maintains communication between the compression line and the heat exchange line, and maintains communication between the evaporation line and the outlet line. During defrosting, the four-way valve maintains communication between the compression line and the evaporation line, and maintains communication between the heat exchange line and the outlet line.

[0014] According to some embodiments of the present invention, an exhaust probe and an exhaust pressure sensor are provided on the compression pipeline. The exhaust probe is used to detect the exhaust temperature of the compressor. When the exhaust temperature is too high, the air supply switch valve will open. The exhaust pressure sensor is used to detect the pressure in the compression pipeline.

[0015] According to some embodiments of the present invention, a return air probe is provided on the inlet pipe, and a return air pressure sensor is provided on the outlet pipe. The return air probe is used to detect the refrigerant temperature of the inlet pipe, and the return air pressure sensor is used to detect the pressure in the outlet pipe.

[0016] According to some embodiments of the present invention, the second branch and the third branch are both connected to bridge-type one-way valves, which are disposed between the heat exchanger and the liquid storage tank, and between the main electronic expansion valve and the evaporator. The bridge-type one-way valve has four one-way valves, which can ensure that the liquid storage tank maintains a positive direction of action under all operating conditions.

[0017] According to some embodiments of the present invention, since the refrigerant entering the evaporator is in a low-pressure state and its flow rate is slow, in order to improve the evaporation efficiency, the third branch is connected to a diverter head downstream of the main electronic expansion valve, and the evaporator is provided with multiple inlets and multiple outlets, all of which are connected to the diverter head, and all of which are connected to the inlet pipe.

[0018] The heat pump according to the second embodiment of the present invention includes a water storage tank, an electric heater and the above-mentioned internal circulation module, and the heat exchanger and the electric heater are both arranged in the water storage tank.

[0019] The heat pump according to the embodiment of the present invention has at least the following beneficial effects: when the compressor is in a normal state, the water in the water tank is heated by the internal circulation module; when a compressor failure is detected, the electric heater replaces the internal circulation module to heat the water in the water tank to maintain normal use of the heat pump.

[0020] According to some embodiments of the present invention, the heat pump further includes a wind pressure tester, the evaporator is connected to a fan, and the wind pressure tester is used to control the speed of the fan. When the wind pressure tester detects an increase in external wind pressure, the fan speed is increased to improve the fan's wind resistance.

[0021] According to some embodiments of the present invention, in order to facilitate adjustment of working parameters, the compressor is a DC variable frequency compressor; and the fan is a DC variable frequency fan.

[0022] According to some embodiments of the present invention, the water tank is connected to a water pump, which can increase the water pressure to reduce the fluctuation of the water flow.

[0023] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0025] Figure 1 This is a structural diagram of the internal circulation module provided by an embodiment of the present utility model;

[0026] Figure 2 It is a structural schematic diagram of a heat pump provided by an embodiment of the utility model.

[0027] In the figure: 10- compressor, 17- four-way valve, 30- heat exchanger, 40- liquid storage tank, 50- filter, 60- economizer, 70- evaporator, 80- gas-liquid separator, 11- return air port, 12- exhaust port, 13- enthalpy increase port, 14- compression pipeline, 15- exhaust probe, 16- exhaust pressure sensor, 31- heat exchange pipeline, 91- first branch, 92- second branch, 93- air supply switch valve, 94- air supply capillary, 61- first inlet, 62- first outlet, 63-Second inlet, 64-Second outlet, 95-Third branch, 96-Fourth branch, 97-Main electronic expansion valve, 98-Auxiliary electronic expansion valve, 71-Fan, 72-Evaporation pipeline, 99-Diverter, 81-Inlet pipeline, 82-Outlet pipeline, 83-Return air probe, 84-Return air pressure sensor, 20-Bridge type one-way valve, 21-First one-way valve, 22-Second one-way valve, 23-Third one-way valve, 24-Fourth one-way valve, 1-Water tank, 2-Electric heater, 3-Water pump. DETAILED DESCRIPTION

[0028] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0029] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0030] In the description of this utility model, "several" means one or more, "more" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The terms "first," "second," "third," and "fourth" are used solely to distinguish technical features and are not to be construed as indicating or implying relative importance, or as implicitly specifying the number or order of the technical features indicated.

[0031] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0032] like Figure 1 As shown, the internal circulation module according to the first embodiment of the present invention includes a compressor 10, a four-way valve 17, a heat exchanger 30, a liquid storage tank 40, a filter 50, an economizer 60, an evaporator 70 and a gas-liquid separator 80, wherein the compressor 10 is provided with a return air port 11, an exhaust port 12, an enthalpy increase port 13 and a cylinder body, and a piston is provided in the cylinder body, which reciprocates in the cylinder body to change the volume of the cylinder body. When the piston moves in the compression direction, the volume of the cylinder body decreases and the gas is compressed. At this time, the intermediate injection port is one-way closed, and the exhaust port 12 is one-way opened under the action of supercharging; when the piston moves in the suction direction, the volume of the cylinder body increases. At this time, the exhaust port 12 is one-way closed, and the intermediate injection port is one-way opened under the action of negative pressure. It can be understood that the return air port 11 and the enthalpy increase port 13 are both connected to the intermediate injection port, so that the refrigerant entering from the return air port 11 and the refrigerant entering from the intermediate injection port can be mixed in the cylinder body.

[0033] For example, the exhaust port 12 of the compressor 10 is connected to a compression line 14, which is equipped with an exhaust probe 15 and an exhaust pressure sensor 16. The exhaust probe 15 is used to detect the exhaust temperature of the compressor 10, and the exhaust pressure sensor 16 is used to detect the pressure in the compression line 14, i.e., the exhaust volume. The following situations can cause the exhaust volume of the compressor 10 to be too low: first, a malfunction of the compressor 10; second, a decrease in the gaseous refrigerant in the return air. Since the compressor 10 cannot compress liquid refrigerant, the reduction in gaseous refrigerant will inevitably lead to a decrease in exhaust volume; third, a refrigerant leak, resulting in a refrigerant shortage.

[0034] Exemplarily, the heat exchanger 30 has a refrigerant inlet and a refrigerant outlet. The refrigerant inlet is connected to a heat exchange pipeline 31, which is connected to the compression pipeline 14 via a four-way valve 17. The refrigerant outlet is connected to a three-way pipeline a, which includes a heat exchange branch, a first branch 91, and a second branch 92. The heat exchange branch is directly connected to the refrigerant outlet, and the three-way pipeline a is divided into the first branch 91 and the second branch 92 from the downstream direction of the heat exchange branch. The heat exchanger 30 is provided with a long elbow pipe, which can be a copper pipe with multiple heat exchange fins connected to its surface. After the compressor 10 delivers high-temperature and high-pressure gaseous refrigerant to the heat exchanger 30, the refrigerant flows unidirectionally in the long elbow pipe. The heat exchanger 30 is generally placed in the medium to be heated, such as water. Since the temperature of the refrigerant in the long elbow pipe is higher than that of the medium, the heat in the refrigerant is exchanged with the medium through the heat exchanger 30, thereby raising the temperature of the medium.

[0035] After heat exchange, the refrigerant is a room-temperature, high-pressure liquid. It can enter the first branch 91 and the second branch 92 through the three-way pipe a. The first branch 91 is sequentially equipped with an air supply on-off valve 93 and an air supply capillary tube 94. The air supply on-off valve 93, which can be a solenoid valve, opens according to the exhaust temperature detected by the exhaust probe 15. When the exhaust temperature of the compressor 10 exceeds a predetermined value, specifically 90°C, the air supply on-off valve 93 opens, connecting the heat exchange branch with the first branch 91. The higher the exhaust temperature, the wider the opening of the air supply on-off valve 93. After passing through the air supply capillary tube 94, the refrigerant in the first branch 91 is converted into a low-temperature, low-pressure gas-liquid mixed refrigerant. When the exhaust temperature of the compressor 10 falls below a predetermined value, the air supply on-off valve 93 closes, sealing the heat exchange branch from the first branch 91. At this point, all the refrigerant in the heat exchange branch flows into the second branch 92.

[0036] The second branch 92 is provided with a liquid storage tank 40 and a filter 50 in sequence, and the downstream end of the second branch 92 is connected to the economizer 60. The liquid storage tank 40 and the filter 50 are both existing technologies. The liquid storage tank 40 can provide a buffer space to prevent pressure anomalies and protect the normal operation of the internal circulation module; while the filter 50 can filter impurities in the refrigerant to prevent impurities from participating in the internal circulation of the refrigerant. It can be understood that the definition of upstream and downstream is based on the normal flow direction of the refrigerant. In normal use, the refrigerant will only flow from upstream to downstream, but in special working conditions, such as defrosting, the refrigerant may flow from the original downstream to the original upstream.

[0037] Exemplarily, the economizer 60 includes a main refrigerant circuit and a secondary refrigerant circuit. The main refrigerant circuit has a first inlet 61 and a first outlet 62 that are interconnected. The first inlet 61 is connected to the downstream end of the second branch circuit 92, while the secondary refrigerant circuit has a second inlet 63 and a second outlet 64 that are interconnected. In the economizer 60, the refrigerant in the main refrigerant circuit can exchange heat with the refrigerant in the secondary refrigerant circuit. The first outlet 62 is connected to a three-way pipe b, which includes an economizer branch, a third branch 95, and a fourth branch 96. The economizer branch is directly connected to the first outlet 62. The three-way pipe b branches downstream of the economizer branch into a third branch 95 and a fourth branch 96. A main electronic expansion valve 97 is provided on the third branch 95, and the downstream end of the third branch 95 is connected to the evaporator 70, while a secondary electronic expansion valve 98 is provided on the fourth branch 96, and the downstream end of the fourth branch 96 is connected to the second inlet 63, and the second outlet 64 is connected to the enthalpy increase port 13 of the compressor 10 through the enthalpy increase pipeline.

[0038] It should be noted that the main electronic expansion valve 97 on the third branch 95 remains normally open, while the auxiliary electronic expansion valve 98 on the fourth branch 96 opens adaptively based on the ambient temperature. The auxiliary electronic expansion valve 98 generally opens when the ambient temperature is below 5°C. When the auxiliary electronic expansion valve 98 is open, the refrigerant flowing out of the first outlet 62 of the economizer 60 flows through the third branch 95 and the fourth branch 96 respectively. When the auxiliary electronic expansion valve 98 is closed, the refrigerant flowing out of the first outlet 62 of the economizer 60 flows entirely into the third branch 95.

[0039] Exemplarily, the evaporator 70 is equipped with an evaporation tube, which can be a copper tube. The evaporation tube has an inlet and an outlet. Refrigerant flows into the evaporation tube from the inlet and flows out of the evaporation tube to the outlet. The downstream end of the third branch 95 is connected to the inlet, allowing the refrigerant in the third branch 95 to flow into the evaporator 70 after passing through the main electronic expansion valve 97. Because the evaporator 70 needs to maintain heat exchange with the external environment, to improve heat exchange efficiency, the evaporator 70 also includes evaporation fins and a fan 71. The fan 71 continuously blows external air into the evaporator 70, while the evaporation fins enhance the heat exchange efficiency between the evaporator 70 and the air. The outlet of the evaporator 70 is connected to the evaporation line 72, which is connected to the four-way valve 17.

[0040] Because the refrigerant entering the evaporator 70 is at a low pressure and has a slow flow rate, to improve evaporation efficiency, a diverter 99 is connected to the third branch 95 downstream of the main electronic expansion valve 97. The evaporator 70 is equipped with multiple evaporation tubes, each with an inlet and an outlet. All inlets are connected to the diverter 99, and all outlets are connected to the evaporation line 72. After passing through the main electronic expansion valve 97 and reducing its pressure and temperature, the refrigerant in the third branch 95 is converted into a low-temperature, low-pressure liquid refrigerant. The refrigerant then flows uniformly through the diverter 99 and is sprayed into each evaporation tube, preventing the refrigerant from flowing within a single evaporation tube and improving the fluidity of the evaporator 70.

[0041] Exemplarily, the gas-liquid separator 80 is connected to an inlet pipe 81 and an outlet pipe 82. The inlet pipe 81 is connected to the evaporation pipe 72 via a four-way valve 17. The downstream end of the first branch pipe 91 is connected to the inlet pipe 81, allowing the refrigerant in the first branch pipe 91 to flow into the inlet pipe 81. The outlet pipe 82 is connected to the return air port 11 of the compressor 10. Since the compressor 10 cannot compress liquid refrigerant, the gas-liquid separator 80 is required to be installed upstream of the return air port 11 of the compressor 10 to prevent the liquid refrigerant from being drawn into the cylinder of the compressor 10. When the gas-liquid mixed refrigerant enters the gas-liquid separator 80, the gas-liquid separator 80 utilizes the difference in density between the gas and liquid to separate the gas and liquid by expanding the pipe diameter, reducing the velocity, and changing the direction of the velocity. The gaseous refrigerant is then drawn into the compressor 10 through the outlet pipe 82, while the liquid refrigerant is retained in the gas-liquid separator 80, awaiting its gradual conversion into gaseous refrigerant.

[0042] Furthermore, a return air probe 83 is provided on the inlet pipe 81, and a return air pressure sensor 84 is provided on the outlet pipe 82. The return air probe 83 is used to detect the refrigerant temperature of the inlet pipe 81, and the return air pressure sensor 84 is used to detect the pressure in the outlet pipe 82, that is, the return air volume. The following situations will cause the return air volume of the compressor 10 to be too low. First, the outside temperature drops, resulting in a deterioration in the heat exchange effect of the refrigerant in the evaporator 70; second, the refrigerant leaks, resulting in insufficient refrigerant. When the return air volume is insufficient, the return air pressure sensor 84 provides feedback to the central controller, and the compressor 10 increases its power under the control of the central controller. If the compressor 10 is a DC variable frequency compressor, the power of the DC variable frequency compressor can be adjusted by changing the frequency of the DC variable frequency compressor.

[0043] It should be further explained that during heating, four-way valve 17 maintains communication between compression line 14 and heat exchange line 31, and maintains communication between evaporation line 72 and outlet line 82. However, during defrosting, four-way valve 17 maintains communication between compression line 14 and evaporation line 72, and maintains communication between heat exchange line 31 and outlet line 82. In other words, four-way valve 17 is used to maintain communication between two lines and can adjust the connection and disconnection between lines according to different operating conditions.

[0044] For existing heat pumps, when the ambient temperature is lower than a certain value, the compressor 10 cannot obtain sufficient gaseous refrigerant from the main circuit. At this time, the power of the compressor 10 needs to be increased equivalently to improve the fluidity of the refrigerant in the internal circulation module. In this process, the exhaust temperature of the compressor 10 will increase. The increase in the exhaust temperature of the compressor 10 is a double-edged sword. The advantage is that it can increase the temperature of the refrigerant in the heat exchanger 30 to meet the heating needs. The disadvantage is that the pipeline is prone to cause the compressor to get stuck in a long-term high temperature and high pressure environment. Once the compressor gets stuck, the piston and the cylinder body will get stuck, causing the compressor to fail to work normally.

[0045] To ensure the heat pump operates normally in a low-temperature environment, when the ambient temperature falls below a set value, typically 5°C, the auxiliary electronic expansion valve 98 of the fourth branch 96 is activated. The refrigerant flowing from the first outlet 62 of the economizer 60 flows through the third branch 95 and the fourth branch 96, respectively. The refrigerant in the third branch 95 flows through the main electronic expansion valve 97, the diverter 99, the evaporator 70, and the gas-liquid separator 80 according to the existing path. The refrigerant in the fourth branch 96 is converted into a low-temperature, low-pressure liquid refrigerant after passing through the auxiliary electronic expansion valve 98. This refrigerant exchanges heat with the main refrigerant of the economizer 60 and flows into the compressor 10 through the enthalpy increase port 13. It is sucked into the middle injection port of the compressor 10 and mixed with the refrigerant in the main circuit to produce an enthalpy increase effect, thereby increasing the heating capacity. In other words, the present invention increases the temperature and amount of the refrigerant in the cylinder of the compressor 10 by increasing the enthalpy, allowing the compressor 10 to increase the heating capacity without significantly increasing the power.

[0046] The opening of the auxiliary electronic expansion valve 98 is adjusted according to the ambient temperature. The lower the ambient temperature, the larger the opening of the auxiliary electronic expansion valve 98. When the opening of the auxiliary electronic expansion valve 98 is small, the gaseous refrigerant in the compressor 10 will become less and less, causing the exhaust temperature of the compressor 10 to increase. To suppress the rise in exhaust temperature, when the exhaust temperature of the compressor 10 exceeds a predetermined value, generally 90°C, the air supply switch valve 93 on the first branch 91 opens. The refrigerant flowing out of the refrigerant outlet of the heat exchanger 30 flows through the first branch 91 and the second branch 92 respectively. The refrigerant in the second branch 92 flows through the liquid storage tank 40 and the filter 50 according to the existing path, and flows into the economizer 60. The refrigerant in the first branch 91 is reduced in pressure and temperature by the air supply capillary 94 before being transported to the inlet pipe 81. This lowers the exhaust temperature of the compressor 10 by reducing the return air temperature, and replenishes a certain amount of gaseous refrigerant to the compressor 10, preventing the compressor 10 from seizure due to excessively high exhaust temperature.

[0047] In some embodiments of the present invention, the second branch 92 and the third branch 95 are both connected to a bridge-type one-way valve 20. The bridge-type one-way valve 20 is arranged between the heat exchanger 30 and the liquid storage tank 40, and between the main electronic expansion valve 97 and the diverter head 99. The function of the bridge-type one-way valve 20 is to ensure that the positive direction of the liquid storage tank 40 is maintained under any working conditions.

[0048] Specifically, the bridge-type one-way valve 20 comprises four one-way valves: a first one-way valve 21, a second one-way valve 22, a third one-way valve 23, and a fourth one-way valve 24. Each of these four one-way valves has an input and an output port, corresponding to the direction of flow. The upstream portion of the second branch 92 is connected to the input port of the first one-way valve 21 and the output port of the second one-way valve 22. The output ports of the first one-way valve 21 and the output ports of the fourth one-way valve 24 are both connected to the tank inlet of the liquid storage tank 40. The tank outlet of the liquid storage tank 40 is connected to the filter 50 via a pipeline. The third branch 95 is connected to the input port of the second one-way valve 22 and the input port of the third one-way valve 23, downstream of the main electronic expansion valve 97. The output port of the third one-way valve 23 and the input port of the fourth one-way valve 24 are both connected upstream of the diverter 99 of the third branch 95.

[0049] During heating, the refrigerant in the heat exchange branch passes through the second branch 92 and flows unidirectionally through the first one-way valve 21 to the tank inlet of the liquid storage tank 40. The refrigerant then flows from the tank outlet to the filter 50. Because the refrigerant in the second branch 92 cannot pass through the second and fourth one-way valves 22 and 24, the output ports of the second and fourth one-way valves 22 and 24 are both at high pressure. When the refrigerant in the third branch 95 enters the bridge one-way valve 20, the output ports of the second and fourth one-way valves 22 and 24 remain at high pressure, while the refrigerant passing through the main electronic expansion valve 97 is at low pressure. Therefore, the refrigerant can only flow unidirectionally through the third one-way valve 23 to the diverter 99.

[0050] During defrost, the refrigerant flows from the evaporator 70 to the third branch 95. At this point, the refrigerant in the third branch 95 cannot pass through the third one-way valve 23 and the first one-way valve 21, and can only flow unidirectionally through the fourth one-way valve 24 to the tank inlet of the liquid storage tank 40, causing the output of the third one-way valve 23 to be at high pressure. The refrigerant then flows from the tank outlet through the filter 50, the economizer 60, and the main electronic expansion valve 97. Because the output of the third one-way valve 23 remains at high pressure, while the refrigerant passing through the main electronic expansion valve 97 is at low pressure, the refrigerant can only flow unidirectionally through the second one-way valve 22 to the heat exchange branch and cannot pass through the third one-way valve 23. The refrigerant then passes through the heat exchanger 30, the four-way valve 17, and the gas-liquid separator 80, ultimately returning to the compressor 10.

[0051] like Figure 1 and Figure 2As shown, a heat pump according to an embodiment of the second aspect of the present invention includes the internal circulation module according to the embodiment of the first aspect of the present invention, as well as a water tank 1 and an electric heater 2. The heat exchanger 30 of the internal circulation module and the electric heater 2 are both located within the water tank 1. When the compressor 10 is operating normally, the water in the water tank 1 is heated by the internal circulation module. If a failure of the compressor 10 is detected, the electric heater 2 replaces the internal circulation module to heat the water in the water tank 1, thereby maintaining normal operation of the heat pump.

[0052] In some embodiments of the present invention, the heat pump further includes a wind pressure tester (not shown in the drawings) for controlling the speed of the fan 71 blowing toward the evaporator 70. When the wind pressure tester detects an increase in the external wind pressure, the speed of the fan 71 is increased to improve the wind resistance of the fan 71.

[0053] In some embodiments of the present invention, the water tank 1 is connected to a water pump 3, which can increase the water pressure to reduce the fluctuation of the water flow. If the water pump 3 is not provided and only the water pressure of the tap water pipe is relied upon, it is easy to cause the water flow to fluctuate, resulting in uneven water output.

[0054] To facilitate adjustment of operating parameters, in this embodiment, the compressor 10 can be a DC variable-frequency compressor, the fan 71 can be a DC variable-frequency fan, the water pump 3 can be a DC water pump, and the electric heater 2 can be a DC variable-frequency electric heater. The DC variable-frequency compressor is controlled so that when the set water temperature does not meet the required value, the operating frequency of the DC variable-frequency compressor increases to a limited maximum frequency, with a set maximum frequency for each operating point. The DC variable-frequency electric heater is controlled in a step-by-step manner based on the water temperature, with the frequency increasing by 5 Hz for every 1°C drop in water temperature until full load operation is achieved. The motor power of the DC water pump and DC variable-frequency fan is only one-third that of an AC motor, allowing for very convenient adjustment of various operating parameters.

[0055] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. Internal circulation module, characterized in that: include: A compressor (10) is provided with an air return port (11), an air discharge port (12), an enthalpy increase port (13), and a cylinder body, wherein the cylinder body takes in air from the air return port (11) and / or the enthalpy increase port (13), and discharges air to the air discharge port (12); A heat exchanger (30) is provided with a refrigerant inlet and a refrigerant outlet, wherein the refrigerant inlet is communicated with the exhaust port (12), and the refrigerant outlet is connected to a three-way pipe a, wherein the three-way pipe a includes a first branch (91) and a second branch (92), wherein an air supply switch valve (93) and an air supply capillary (94) are sequentially provided on the first branch (91), and a liquid storage tank (40) and a filter (50) are sequentially provided on the second branch (92); An economizer (60) is provided with a first inlet (61) and a first outlet (62) that are interconnected, and a second inlet (63) and a second outlet (64) that are interconnected. The second branch (92) is connected to the first inlet (61). The first outlet (62) is connected to a three-way pipe b. The three-way pipe b includes a third branch (95) and a fourth branch (96). A main electronic expansion valve (97) is provided on the third branch (95). A secondary electronic expansion valve (98) is provided on the fourth branch (96). The fourth branch (96) is connected to the second inlet (63). The second outlet (64) is connected to the enthalpy increase port (13). an evaporator (70) having an inlet and an outlet, wherein the third branch (95) is connected to the inlet; The gas-liquid separator (80) is connected to an inlet pipeline (81) and an outlet pipeline (82), wherein the inlet pipeline (81) is in communication with the outflow port, the first branch (91) is in communication with the inlet pipeline (81), and the outlet pipeline (82) is connected to the gas return port (11).

2. The internal circulation module according to claim 1, characterized in that: It also includes a four-way valve (17), which is respectively connected to a compression pipeline (14), a heat exchange pipeline (31), an evaporation pipeline (72) and the outlet pipeline (82), wherein the compression pipeline (14) is connected to the exhaust port (12), the heat exchange pipeline (31) is connected to the refrigerant inlet, and the evaporation pipeline (72) is connected to the outflow port.

3. The internal circulation module according to claim 2, characterized in that: An exhaust probe (15) and an exhaust pressure sensor (16) are provided on the compression pipeline (14).

4. The internal circulation module according to claim 1, characterized in that: The inlet pipe (81) is provided with a return air probe (83); the outlet pipe (82) is provided with a return air pressure sensor (84).

5. The internal circulation module according to claim 1, characterized in that: The second branch (92) and the third branch (95) are both connected to a bridge-type one-way valve (20). The bridge-type one-way valve (20) is provided between the heat exchanger (30) and the liquid storage tank (40), and between the main electronic expansion valve (97) and the evaporator (70).

6. The internal circulation module according to claim 1, characterized in that: The third branch (95) is connected to a diverter (99) downstream of the main electronic expansion valve (97), and the evaporator (70) is provided with a plurality of inlets and a plurality of outlets, all of which are in communication with the diverter (99), and all of which are in communication with the inlet pipe (81).

7. A heat pump, characterized in that include: Water storage tank (1); The internal circulation module according to any one of claims 1 to 6, wherein the heat exchanger (30) is arranged in the water storage tank (1); An electric heater (2) is arranged in the water storage tank (1).

8. The heat pump according to claim 7, characterized in that: It also includes a wind pressure tester, the evaporator (70) is connected to a fan (71), and the wind pressure tester is used to control the rotation speed of the fan (71).

9. The heat pump according to claim 8, characterized in that: The compressor (10) is a DC variable frequency compressor; the fan (71) is a DC variable frequency fan.

10. The heat pump according to claim 7, characterized in that: The water storage tank (1) is connected to a water pump (3).

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