Gas-liquid separator, heat pump system, and control method

Abstract

The application discloses a gas-liquid separator, a heat pump system and a control method, wherein the gas-liquid separator comprises a tank body, a working medium pipe assembly and a heat exchange assembly; a containing cavity is formed in the tank body; the working medium pipe assembly comprises a working medium inlet pipe, a working medium outlet pipe and a high-pressure gas pipe which are arranged on the tank body at intervals; the working medium inlet pipe and the working medium outlet pipe are used for communicating with the containing cavity; the high-pressure gas pipe is arranged in the tank body and both ends thereof are located outside the tank body; the heat exchange assembly is arranged in the containing cavity and on a pipe section of the high-pressure gas pipe in the containing cavity; the heat exchange assembly comprises a partition plate and a plurality of heat exchange plates; the partition plate is arranged in the high-pressure gas pipe and separates the inside of the high-pressure gas pipe to form an inlet pipe section and an outlet pipe section; the plurality of heat exchange plates are connected with the outer wall of the high-pressure gas pipe and are arranged around the high-pressure gas pipe; a gas flow channel is arranged in the heat exchange plate; and the gas flow channel communicates with the inlet pipe section and the outlet pipe section. The technical scheme can realize efficient heat exchange of the gas-liquid separator.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heating and ventilation systems, and in particular to a gas-liquid separator, a heat pump system, and a control method. BACKGROUND

[0002] Heat pump technology is an energy-saving technology that can efficiently utilize low-grade energy, and has broad application prospects in building heating, industrial waste heat utilization, new energy, and other fields.

[0003] In related technologies, when the compressor of a heat pump system is working, a large amount of liquid refrigerant is likely to enter the compressor, causing liquid hammering, affecting the normal operation of the compressor, and even causing operational failure. To avoid this phenomenon, a gas-liquid separator is usually provided to separate the liquid and gaseous refrigerants and prevent the liquid refrigerant from entering the compressor. However, under low-temperature working conditions, the evaporator is prone to frosting, and the outdoor unit needs to be in a defrosting mode to defrost the evaporator to ensure the operating efficiency of the unit. At this time, the gas-liquid separator accumulates too much liquid refrigerant inside due to low heat exchange efficiency, which also causes the compressor to have "liquid hammering" and reduces the system operating stability. SUMMARY

[0004] The embodiments of the present application provide a gas-liquid separator, a heat pump system, and a control method, which can achieve efficient heat exchange of the gas-liquid separator.

[0005] In a first aspect, the embodiments of the present application provide a gas-liquid separator, which includes a tank body, a working medium pipe assembly, and a heat exchange assembly. The tank body forms an accommodation cavity inside. The working medium pipe assembly includes a working medium inlet pipe, a working medium outlet pipe, and a high-pressure gas pipe, which are arranged at intervals on the tank body. One part of the working medium inlet pipe is located outside the tank body, and the other part is located inside the accommodation cavity and is used to communicate with the accommodation cavity. One part of the working medium outlet pipe is located outside the tank body, and the other part is located inside the accommodation cavity and is used to communicate with the accommodation cavity. The high-pressure gas pipe is arranged in the tank body, and both ends thereof are located outside the tank body. The heat exchange assembly is arranged in the accommodation cavity and is arranged on the pipe segment of the high-pressure gas pipe located in the accommodation cavity. The heat exchange assembly includes a partition plate and a plurality of heat exchange plates. The partition plate is arranged in the high-pressure gas pipe and separates the inside of the high-pressure gas pipe to form an inlet gas pipe segment and an outlet gas pipe segment. The plurality of heat exchange plates are connected with the outer wall of the high-pressure gas pipe and are arranged around the high-pressure gas pipe. The heat exchange plates are provided with gas flow channels. The gas flow channels communicate with the inlet gas pipe segment and the outlet gas pipe segment.

[0006] In some embodiments, the plurality of heat exchange plates are distributed radially along the high-pressure gas pipe.

[0007] In some embodiments, the gas flow channel comprises a plurality of parallelly arranged gas inlet microchannels, a gas collecting channel, and a plurality of parallelly arranged gas outlet microchannels, the plurality of gas inlet microchannels being in communication with the gas inlet pipe section and the gas collecting channel, and the plurality of gas outlet microchannels being in communication with the gas collecting channel and the gas outlet pipe section.

[0008] In some embodiments, the gas outlet pipe section is arranged through a side wall or a bottom wall of the tank body and extends outside the tank body.

[0009] In some embodiments, the working fluid inlet pipe has an inlet pipe outlet arranged in the accommodating cavity, and the inlet pipe outlet is arranged above the heat exchange assembly.

[0010] In some embodiments, the inlet pipe outlet is arranged towards an inner side wall of the tank body.

[0011] In some embodiments, the working fluid outlet pipe has an outlet pipe inlet arranged in the accommodating cavity, and the outlet pipe inlet is arranged adjacent to a top of the tank body and is arranged higher than the inlet pipe outlet.

[0012] In some embodiments, the tank body comprises a container body and an upper end cover connected to each other, the container body and the upper end cover enclose the accommodating cavity, the working fluid inlet pipe and the working fluid outlet pipe are fixedly arranged on the upper end cover, and the high-pressure gas pipe is arranged through the upper end cover and the container body.

[0013] In a second aspect, the embodiments of the present application provide a heat pump system, comprising an outdoor unit and a hydraulic module connected by pipelines, the outdoor unit comprising a compressor, an air cooler, a heat exchanger, an evaporator and a gas-liquid separator as described in any one of the above embodiments, and the hydraulic module comprising the air cooler;

[0014] The compressor has an exhaust port and a return port, a first pipeline and a second pipeline are arranged in parallel at the exhaust port of the compressor, the exhaust port is connected to the gas inlet port of the air cooler through the first pipeline, the exhaust port is connected to the gas pipe inlet of the high-pressure gas pipe through the second pipeline, the gas pipe outlet of the high-pressure gas pipe is connected to the gas inlet port of the air cooler, and the return port is connected to the outlet pipe outlet of the working fluid outlet pipe;

[0015] The gas outlet port of the air cooler is connected to the first inlet port of the heat exchanger, the first outlet port of the heat exchanger is connected to the gas inlet port of the evaporator, the gas outlet port of the evaporator is connected to the second inlet port of the heat exchanger, and the second outlet port of the heat exchanger is connected to the inlet pipe inlet of the working fluid inlet pipe of the gas-liquid separator;

[0016] The outdoor unit further comprises a valve assembly and a throttling assembly, the valve assembly comprises a first stop valve, a second stop valve and a defrost bypass valve, the throttling assembly comprises a throttling valve and a defrost capillary, the first stop valve is arranged on the first pipeline, the second stop valve is arranged on the second pipeline, and the throttling valve is arranged between the first outlet of the heat regenerator and the gas inlet of the evaporator;

[0017] The outdoor unit further comprises a bypass, the bypass connects the gas outlet of the compressor and the gas inlet of the evaporator, and the defrost bypass valve and the defrost capillary are arranged in series on the bypass.

[0018] In a third aspect, the embodiments of the present application provide a control method, which is used for the heat pump system as described above, and the steps comprise:

[0019] S1: collecting an outdoor air temperature t1 and a humidity parameter, setting evaporator fin temperature preset values t3 and t4, and judging whether the evaporator is likely to frost according to the collected outdoor air temperature t1 and the humidity parameter;

[0020] S2: if the evaporator is likely to frost, collecting an evaporator fin temperature t2, and judging whether the evaporator fin temperature t2 is greater than the preset value t3, if the evaporator is not likely to frost, controlling the first stop valve to be opened, and the second stop valve and the defrost bypass valve to be closed, so as to run the heating mode;

[0021] S3: if the evaporator fin temperature t2 is less than or equal to the preset value t3, controlling the first stop valve to be closed, and the second stop valve and the defrost bypass valve to be opened, so as to run the defrosting mode, if the evaporator fin temperature t2 is greater than the preset value t3, controlling the first stop valve to be opened, and the second stop valve and the defrost bypass valve to be closed, so as to continue to run the heating mode.

[0022] In some embodiments, after running the defrosting mode, an evaporator fin temperature t5 is collected after a preset time t, and it is judged whether the evaporator fin temperature t5 is greater than the preset value t4;

[0023] If the evaporator fin temperature t5 is less than or equal to the preset value t4, the first stop valve is controlled to be closed, and the second stop valve and the defrost bypass valve are controlled to be opened, so as to continue to run the defrosting mode, if the evaporator fin temperature t5 is greater than the preset value t4, the first stop valve is controlled to be opened, and the second stop valve and the defrost bypass valve are controlled to be closed, so as to run the heating mode.

[0024] The gas-liquid separator based on this application embodiment has a receiving cavity formed inside the tank. The working fluid enters the gas-liquid separator; due to gravity, the liquid sinks and adheres to the inner wall of the tank, storing within the receiving cavity to prevent backflow and liquid hammer. A portion of the working fluid inlet pipe is located outside the tank, and another portion is located inside the receiving cavity and connects to it, facilitating the storage of the liquid working fluid and the separation of liquid and gaseous working fluids. A portion of the working fluid outlet pipe is located outside the tank, and another portion is located inside the receiving cavity and connects to it, allowing the gaseous working fluid separated from the gas-liquid separator to continue its working cycle within the heat pump system.

[0025] A high-pressure gas pipe runs through the tank body, with both ends located outside the tank. A high-temperature, high-pressure gaseous working fluid is introduced into the high-pressure gas pipe and exchanges heat with the low-temperature working fluid inside the containment cavity. This process converts the liquid working fluid into a gaseous state through high temperature, reducing the risk of liquid slugging. The heat exchange assembly is located inside the containment cavity of the tank body, on the section of the high-pressure gas pipe within the containment cavity. This allows for closer contact with the low-temperature, low-pressure working fluid inside the containment cavity, reducing heat transfer distance and heat loss. This enables direct heat exchange between the high and low pressure sides inside the tank, evaporating the liquid working fluid inside the tank, reducing the amount of liquid working fluid stored in the tank, resulting in high heat exchange efficiency. Furthermore, it avoids liquid slugging, enhances system reliability, and thus improves heat exchange efficiency. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of an embodiment of the heat pump system of this application;

[0028] Figure 2 for Figure 1 The diagram shows the structural schematic of the heating mode of the heat pump system.

[0029] Figure 3 for Figure 1 The diagram shows the structure of the defrosting mode of the heat pump system.

[0030] Figure 4 for Figure 1 The diagram shows the structure of the gas-liquid separator in the heat pump system.

[0031] Figure 5 for Figure 4 The diagram shows a top view of the structure of the gas-liquid separator.

[0032] Figure 6 For Figure 4 The high-pressure gas pipe and heat exchange assembly of the gas-liquid separator shown in the figure are assembled.

[0033] Figure 7 For Figure 4 The assembly structure of the working medium inlet pipe and working medium outlet pipe of the gas-liquid separator shown in the figure.

[0034] Figure 8 The flow chart of an embodiment of the heat pump system control method.

[0035] Explanation of reference numerals:

[0036] 1, heat pump system; 10, outdoor unit; 100, gas-liquid separator; 110, tank body; 111, containing cavity; 112, container body; 113, upper end cover; 114, lower end cover; 115, support assembly; 120, working medium pipe assembly; 121, working medium inlet pipe; 1211, inlet pipe outlet; 1212, inlet pipe inlet; 122, working medium outlet pipe; 1221, first part; 1221a, outlet pipe outlet; 1222, second part; 1222a, outlet pipe inlet; 1222b, vertical part; 1222c, bending part; 1223, oil return hole; 123, high-pressure gas pipe; 1231, gas inlet pipe section; 1232, gas outlet pipe section; 1233, gas pipe inlet; 1234, gas pipe outlet; 130, heat exchange assembly; 131, partition; 132, heat exchange plate; 133, gas flow channel; 1331, gas inlet microchannel; 1332, flow collecting channel; 1333, gas outlet microchannel; 200, compressor; 210, exhaust port; 220, gas return port; 300, gas cooler; 400, heat exchanger; 410, first inlet; 420, first outlet; 430, second inlet; 440, second outlet; 500, evaporator; 600, valve assembly; 610, first stop valve; 620, second stop valve; 630, defrosting bypass valve; 700, throttling assembly; 710, throttle valve; 720, defrosting capillary; 800, bypass; 900, fan; 20, hydraulic module.

[0037] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present application more clear, the embodiments of the present application will be further described in detail with reference to the accompanying drawings.

[0039] The description of the lower part relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all the embodiments consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application, as detailed in the appended claims.

[0040] In the description of the present application, it is understood that the terms "first", "second" and the like are used only for descriptive purposes and cannot be understood as indicating or implying relative importance. For those skilled in the art, the specific meaning of the above terms in the present application can be understood in specific cases. In addition, in the description of the present application, unless otherwise specified, "multiple" means two or more. The association between the associated objects is described, which means that there can be three relationships, for example, A and / or B, which can mean that A exists alone, A and B exist together, and B exists alone. The character " / " generally represents a "or" relationship between the associated objects before and after.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as understood by those skilled in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0042] Heat pump technology is an energy-saving technology that can efficiently use low-grade energy. As an environmentally friendly and efficient energy conversion device, it has attracted much attention and has great development potential. It has broad application prospects in building heating, industrial waste heat utilization, new energy and other fields. Traditional heat pump water heaters use HCFCs and other refrigerants, which not only harm the atmospheric ozone layer, but also exacerbate the greenhouse effect, posing a serious threat to the environment.

[0043] CO2 itself as an environmentally friendly natural refrigerant has good physical and chemical properties and excellent heating performance. Especially at low temperatures, CO2 has good thermal performance, which is very suitable for transcritical cycle working medium, and has shown great advantages in the field of heat pump technology. Air source CO2 heat pump system has the characteristics of green environmental protection, high energy saving and wide application range. It can provide 60-90℃ hot water in a wide range of environmental temperature, and its application range is wider, especially it can solve the problem of hot water supply under low environmental temperature conditions.

[0044] In the related art, the compressor of the outdoor unit of the air source CO2 heat pump system is prone to the phenomenon that liquid refrigerant lubricating oil is sucked into the cylinder of the compressor along with gaseous refrigerant during the working cycle, which damages the suction valve plate. This phenomenon is commonly referred to as liquid knock. Liquid knock affects the normal operation of the compressor and even causes operation failure. To avoid liquid knock, a gas-liquid separator is usually provided in the outdoor unit of the heat pump system to separate the liquid and gaseous refrigerants and prevent the liquid refrigerant from entering the compressor.

[0045] In the heating mode, the evaporator of the outdoor unit absorbs heat from the ambient air to evaporate the heat transfer working medium. The working medium vapor is compressed by the compressor, and the pressure and temperature of the working medium vapor are increased. The high-temperature vapor transfers heat to the water module through the pipeline, thereby heating the water in the water tank in the water module. When the outdoor temperature is low, the surface temperature of the fins of the evaporator is lower than the dew point temperature of the ambient air, and the water vapor in the air will freeze into liquid on the surface of the fins and adhere to the surface of the fins, thereby forming a frost layer, which reduces the flow of the gas and weakens the heat transfer performance of the evaporator. At this time, the outdoor unit needs to run in the defrosting mode to defrost the surface of the fins of the evaporator, thereby ensuring the operating efficiency of the outdoor unit. However, at this time, the heat exchange efficiency of the gas-liquid separator is not high, and the accumulation of too much liquid refrigerant in the gas-liquid separator will cause liquid knock of the compressor and reduce the stability of the system.

[0046] To solve the above problems, please refer to Figures 1 to 3 The heat pump system 1 includes an outdoor unit 10 and a water module 20 connected by a pipeline. The water module 20 includes an air cooler 300, a water tank, and the like connected to the air cooler 300, for providing hot water to a user end. In addition, the heat pump system 1 further includes an electric control system for controlling the outdoor unit 10 and the water module 20. The electric control system can receive user instructions, adjust the operating speed and operating mode of the indoor unit and the water module 20, and the operating mode of the outdoor unit 10 can include a heating mode and a defrosting mode.

[0047] The outdoor unit 10 can include a casing, a compressor 200, an air cooler 300, a heat exchanger 400, an evaporator 500, and a gas-liquid separator 100 arranged in the casing and connected by a pipeline. The compressor 200 is the core component of the outdoor unit 10, responsible for compressing the working medium and delivering it to the outdoor unit 10. The outdoor unit 10 further includes a valve assembly 600 and a throttling assembly 700, which are controlled by the electric control system to switch between the heating mode and the defrosting mode of the heat pump system 1.

[0048] In addition, the outdoor unit 10 further comprises a fan 900, which is arranged adjacent to the evaporator 500, can suck air from the outdoor environment, and force the air to pass through the evaporator 500, so that the working fluid in the evaporator 500 exchanges heat with the air, and the heat exchange efficiency of the evaporator 500 is improved.

[0049] In some embodiments, the gas-liquid separator 100 mainly protects the compressor 200 from liquid working fluid. Please refer to Figures 3 to 5 The gas-liquid separator 100 comprises a tank body 110, a working fluid pipe assembly 120, and a heat exchange assembly 130. The tank body 110 forms an accommodation cavity 111 inside. The working fluid (usually gas containing a small amount of liquid, and in the air source CO2 heat pump system, the working fluid is CO2) transmitted by the evaporator 500 enters the inside of the gas-liquid separator 100. The liquid is deposited and adhered to the inner wall surface of the tank body 110 due to the large gravity, is stored in the accommodation cavity 111, and the gas continues to flow in the accommodation cavity 111 and is then sucked and compressed by the compressor 200.

[0050] The working fluid pipe assembly 120 comprises a working fluid inlet pipe 121, a working fluid outlet pipe 122, and a high-pressure gas pipe 123, which are arranged on the tank body 110 and are spaced from each other. One part of the working fluid inlet pipe 121 is located outside the tank body 110 and is used to connect the regenerator 400, and the other part is located in the accommodation cavity 111 and is used to communicate the accommodation cavity 111, so as to introduce the working fluid in the regenerator 400 into the accommodation cavity 111 of the gas-liquid separator 100, which is helpful to store the liquid working fluid and separate the liquid and gaseous working fluids.

[0051] One part of the working fluid outlet pipe 122 is located outside the tank body 110 and is used to connect the compressor 200, and the other part is located in the accommodation cavity 111 and is used to communicate the accommodation cavity 111, so as to introduce the gaseous working fluid separated in the gas-liquid separator 100 into the compressor 200 to continue the working cycle.

[0052] The high-pressure gas pipe 123 penetrates the tank body 110 and both ends thereof are located outside the tank body 110. One end is used to connect the compressor 200, and the other end is used to connect the gas cooler 300. The high-pressure gas pipe 123 is connected to the high-temperature and high-pressure gaseous working fluid discharged by the compressor 200, and exchanges heat with the low-temperature working fluid in the accommodation cavity 111, so as to convert the liquid working fluid into gaseous working fluid by high temperature, and reduce the risk of "liquid hammer" phenomenon.

[0053] The heat exchange assembly 130 is arranged in the containing cavity 111 of the tank body 110 and is arranged on the pipe segment of the high-pressure gas pipe 123 located in the containing cavity 111, can be in closer contact with the low-temperature and low-pressure working medium in the containing cavity 111, reduces the distance of heat transfer and reduces heat loss, thereby directly performing heat exchange between the high-pressure side and the low-pressure side inside the tank body 110, evaporating the liquid working medium inside the tank body 110, reducing the storage of the liquid working medium in the tank body 110, having higher heat exchange efficiency, avoiding liquid strike of the compressor 200, enhancing system reliability, thereby improving the heat exchange efficiency.

[0054] Specifically, the compressor 200 has an exhaust port 210 and a return gas port 220, the first pipeline and the second pipeline are arranged in parallel at the exhaust port 210 of the compressor 200, the exhaust port 210 is connected with the gas inlet of the gas cooler 300 through the first pipeline, the exhaust port 210 is connected with the gas pipe inlet 1233 of the high-pressure gas pipe 123 through the second pipeline, the gas pipe outlet 1234 of the high-pressure gas pipe 123 is connected with the gas inlet of the gas cooler 300, and the return gas port 220 is connected with the outlet 1221a of the outlet of the working medium outlet pipe 122.

[0055] The gas outlet of the gas cooler 300 is connected with the first inlet 410 of the regenerator 400, the first outlet 420 of the regenerator 400 is connected with the gas inlet of the evaporator 500, the gas outlet of the evaporator 500 is connected with the second inlet 430 of the regenerator 400, and the second outlet 440 of the regenerator 400 is connected with the inlet 1212 of the working medium inlet pipe 121 of the gas-liquid separator 100.

[0056] The outdoor unit 10 further comprises a valve assembly 600, a throttling assembly 700 and a bypass 800, the valve assembly 600 comprises a first stop valve 610, a second stop valve 620 and a defrosting bypass valve 630, the throttling assembly 700 comprises a throttling valve 710 and a defrosting capillary 720, the first stop valve 610 is arranged on the first pipeline, the second stop valve 620 is arranged on the second pipeline, and the throttling valve 710 is arranged between the first outlet 420 of the regenerator 400 and the gas inlet of the evaporator 500. The bypass 800 is connected with the exhaust port 210 of the compressor 200 and the gas inlet of the evaporator 500, and the defrosting bypass valve 630 and the defrosting capillary 720 are arranged in series on the bypass 800.

[0057] The bypass 800 is used to directly introduce the high-temperature working medium from the compressor 200 into the evaporator 500, and the heat of the high-temperature gas is used to melt the frost layer. The bypass heat gas mode makes the required heat energy in the entire defrosting process come from the heat storage of the compressor 200 and the work of the compressor 200, reduces the heat absorption of the outdoor during defrosting, reduces the possibility of the evaporator 500 being frosted again by the outdoor low-temperature air, improves the defrosting heat exchange efficiency.

[0058] In one specific embodiment of this application, the working fluid of the heat pump system 1 is CO2, and in heating mode, the flow path of the working fluid within the heat pump system 1 is as follows: Figure 2 As shown, the electronic control system controls the first shut-off valve 610 to open, and the second shut-off valve 620 and the defrost bypass valve 630 to close. CO2 flows through the compressor 200 and is compressed into high-temperature, high-pressure gas before entering the air cooler 300. In the air cooler 300, the high-temperature CO2 heats the cooling water flowing into the hydraulic module 20 connected to the air cooler 300 to the target temperature, while the CO2 is isobarically cooled to a low-temperature state. Subsequently, the CO2 is further cooled in the regenerator 400 to reach an even lower temperature. The high-pressure CO2 flows through the throttling valve 710, where the pressure and temperature decrease simultaneously. It vaporizes in the evaporator 500, absorbing heat to the saturation point, and then re-enters the regenerator 400 to be heated. Thus, the heat pump system 1 completes its working cycle in heating mode.

[0059] In defrost mode, the flow path of the working fluid within heat pump system 1 is as follows: Figure 3 As shown, the electronic control system controls the first shut-off valve 610 to close, and the second shut-off valve 620 and the defrost bypass valve 630 to open. Cooling water is either not introduced into the air cooler 300 or only partially introduced. CO2 flows through the compressor 200 and is compressed into high-temperature, high-pressure gas. It is then discharged from the compressor 200's exhaust port 210 and flows into the gas-liquid separator 100 through the gas inlet 1233 of the high-pressure gas pipe 123. There, it exchanges heat with the low-temperature, low-pressure CO2 stored in the gas-liquid separator 100's containment chamber 111 on both high and low pressure sides. It then flows out from the gas outlet 1234 of the high-pressure gas pipe 123, sequentially flowing through the air cooler 300 and the regenerator 400, becoming a high-pressure, low-temperature state. Finally, it flows through the throttle valve 710, where the pressure and... The temperature decreases simultaneously, and it combines with another part of the low-pressure, high-temperature CO2 that flows into the bypass 800 through the exhaust port 210 of the compressor 200 and then flows through the defrost capillary tube 720 where it is throttled and depressurized. It then enters the evaporator 500 for defrosting at high temperature. After defrosting, the low-temperature, low-pressure CO2 passes through the regenerator 400 and flows into the receiving cavity 111 of the gas-liquid separator 100 from the inlet 1212 of the working fluid inlet pipe 121. It exchanges heat with the high-temperature, high-pressure gaseous CO2 flowing in the high-pressure gas pipe 123 and the heat exchange component 130 in the gas-liquid separator 100, and becomes low-pressure gaseous CO2. It then enters the compressor 200 through the working fluid outlet pipe 122. Thus, the heat pump system 1 completes the working cycle in defrost mode.

[0060] Specifically, the heat exchange assembly 130 includes a partition plate 131 and a plurality of heat exchange plates 132. The partition plate 131 is arranged in the high-pressure gas pipe 123 and divides the inside of the high-pressure gas pipe 123 to form an inlet pipe section 1231 and an outlet pipe section 1232. The inlet pipe section 1231 is used to connect the compressor 200, and the outlet pipe section 1232 is used to connect the gas cooler 300. It can be understood that the outlet pipe section 1232 is arranged through the side wall or the bottom wall of the tank body 110 and extends outside the tank body 110. When the outlet pipe section 1232 is arranged through the side wall of the tank body 110, the high-temperature and high-pressure gas is prevented from leaking from the bottom of the tank body 110, and the pipe arrangement is facilitated. When the outlet pipe section 1232 is arranged through the bottom wall of the tank body 110, the outlet pipe section 1232 can be facilitated to discharge gas from top to bottom by gravity, improve the gas discharge efficiency, and further improve the heat exchange efficiency.

[0061] The heat exchange plates 132 are connected with the outer wall of the high-pressure gas pipe 123, and the gas flow channel 133 is arranged in the heat exchange plate 132. The gas flow channel 133 is connected with the inlet pipe section 1231 and the outlet pipe section 1232. Therefore, the high-temperature and high-pressure gas state working medium flowing through the high-pressure gas pipe 123 can all flow into the heat exchange plate 132 and perform heat exchange between the high-pressure side and the low-pressure side of the gas-liquid separator 100.

[0062] The gas flow channel 133 includes a plurality of parallelly arranged inlet microchannels 1331, a flow collecting channel 1332, and a plurality of parallelly arranged exhaust microchannels 1333. The plurality of inlet microchannels 1331 are connected with the inlet pipe section 1231 and the flow collecting channel 1332, and the plurality of exhaust microchannels 1333 are connected with the flow collecting channel 1332 and the outlet pipe section 1232. The arrangement of the gas flow channel 133 changes the gas flow direction in the heat exchange assembly 130, ensures that the high-temperature and high-pressure gas state working medium can fully flow in the heat exchange plate 132, ensures the heat exchange area, and further improves the heat exchange efficiency of the gas-liquid separator 100.

[0063] In the defrosting mode, the exhaust port 210 of the compressor 200 introduces the high-temperature and high-pressure gas state working medium into the gas pipe inlet 1233 of the high-pressure gas pipe 123, and the high-temperature and high-pressure gas state working medium flows from the inlet pipe section 1231 to the inlet microchannel 1331, sequentially flows through the flow collecting channel 1332 and the exhaust microchannel 1333, and then flows from the exhaust microchannel 1333 to the outlet pipe section 1232 of the high-pressure gas pipe 123, and flows into the gas inlet of the gas cooler 300 from the gas pipe outlet 1234. In the whole process, the high-temperature and high-pressure gas state working medium in the high-pressure gas pipe 123 continuously exchanges heat with the low-temperature and low-pressure working medium flowing into the inside of the tank body 110 from the working medium inlet pipe 121, which can greatly improve the rate of the low-temperature and low-pressure liquid state working medium converted into the gas state working medium by high-temperature evaporation, and can also heat the low-temperature and low-pressure gas state working medium to improve the temperature before entering the compressor 200, improve the working efficiency of the compressor 200, and thus improve the working efficiency of the heat pump system 1.

[0064] It can be understood that the heat exchange plates 132 are provided in multiple numbers, the multiple heat exchange plates 132 are arranged around the high-pressure gas pipe 123 and distributed radially along the high-pressure gas pipe 123, which can achieve more uniform temperature distribution, increase the heat exchange area, and allow the multiple heat exchange plates 132 to be adjusted according to different application requirements, for example, by changing the size or position of the radiation range to adapt to specific pipe wall size requirements, and the heat exchange plate 132 in this form is relatively simple in manufacturing process, thereby reducing the cost while ensuring the heat exchange area.

[0065] In some embodiments, the tank body 110 includes a container body 112, an upper end cover 113 and a lower end cover 114 connected together, which can be connected by welding or the like to ensure the connection strength, and the split design facilitates process control, and when maintenance or replacement of parts is required, it can be more easily disassembled and reassembled. The upper end cover 113 and the lower end cover 114 are arranged opposite in the up-down direction of the tank body 110, and the container body 112, the upper end cover 113 and the lower end cover 114 enclose the accommodation cavity 111, which can provide a stable storage and gasification space for the working medium and reduce the risk of leakage of the bottom wall liquid working medium. The working medium inlet pipe 121 and the working medium outlet pipe 122 are fixedly arranged on the upper end cover 113, and the high-pressure gas pipe 123 is arranged through the upper end cover 113 and the container body 112, which can optimize the flow path of the working medium in the accommodation cavity 111, reduce the flow resistance and improve the gasification efficiency.

[0066] It can be understood that the tank body 110 can also not be provided with the lower end cover 114, but the container body 112 and the upper end cover 113 enclose the accommodation cavity 111, i.e., the bottom wall and the side wall of the container body 112 are of an integrated structure, which can save production manufacturing costs and further ensure the airtightness of the container body 112 to avoid leakage.

[0067] The working medium inlet pipe 121 has an inlet pipe outlet 1211 located in the accommodation cavity 111, and the working medium outlet pipe 122 has an outlet pipe inlet 1222a located in the accommodation cavity 111, wherein the inlet pipe outlet 1211 is located above the heat exchange assembly 130, when the low-temperature and low-pressure liquid working medium flows into the accommodation cavity 111 from the inlet pipe outlet 1211 of the working medium inlet pipe 121, the low-temperature and low-pressure liquid working medium falls from top to bottom to the bottom wall of the accommodation cavity 111, in this falling process, the low-temperature and low-pressure liquid working medium can be once heated with the high-temperature and high-pressure gaseous working medium in the high-pressure gas pipe 123 and the heat exchange assembly 130, and when the liquid working medium on the bottom wall is gasified, it rises from bottom to top and flows into the working medium outlet pipe 122 from the outlet pipe inlet 1222a, in this rising process, the gaseous working medium can be further heated twice with the high-temperature and high-pressure gaseous working medium in the high-pressure gas pipe 123 and the heat exchange assembly 130, thereby prolonging the heat exchange time and further improving the heat exchange efficiency.

[0068] Furthermore, the inlet pipe outlet 1211 is located in the accommodating cavity 111 close to the upper end cover 113, so that the liquid working medium flowing into the accommodating cavity 111 has a longer flow path, and the heat exchange time of the liquid working medium before it accumulates to the bottom wall of the accommodating cavity 111 is increased, thereby improving the heat exchange efficiency.

[0069] Further, the outlet pipe inlet 1222a is arranged higher than the inlet pipe outlet 1211, so that the higher outlet pipe inlet 1222a from the inlet pipe outlet 1211 into the accommodating cavity 111 helps to reduce the mixing between the gaseous working medium and the working medium flowing out of the inlet pipe outlet 1211, thereby maintaining the effective separation of the gaseous and liquid working media.

[0070] In addition, the inlet pipe outlet 1211 is arranged towards the inner side wall of the tank body 110, and the liquid working medium can flow under the guidance of the cavity side wall. It can be understood that, in the process of the working medium flowing downwards along the cavity side wall, the working medium forms a wide flow liquid surface. In the case of heat exchange with the heat exchange assembly 130, the heat exchange effect can be effectively improved, thereby fully separating the gas and liquid, and reducing the liquid working medium entering the working medium outlet pipe 122; and the outlet pipe inlet 1222a of the working medium outlet pipe 122 is arranged towards the cavity top wall of the accommodating cavity 111, i.e., the inlet pipe outlet 1211 and the outlet pipe inlet 1222a are arranged in different directions. In this way, it can also prevent the liquid working medium flowing out of the inlet pipe outlet 1211 of the working medium inlet pipe 121 from flowing into the outlet pipe inlet 1222a of the working medium outlet pipe 122 without being gasified. The working medium entering the inlet pipe outlet 1211 needs to flow in the accommodating cavity 111 and undergo the gas-liquid separation process, and the working medium does not directly impact the working medium outlet pipe 122, reducing the impact on the working medium outlet pipe 122, reducing the vibration of the working medium outlet pipe 122, and the outlet pipe inlet 1222a arranged towards the cavity top wall of the accommodating cavity 111 can also better converge and discharge the gaseous working medium rising to the top of the accommodating cavity 111, which can further improve the gas-liquid separation effect.

[0071] The cavity side wall of the accommodating cavity 111 includes a working medium flow area. Since the inlet pipe outlet 1211 of the working medium inlet pipe 121 is arranged towards the side wall of the accommodating cavity 111, the working medium falling from the inlet pipe outlet 1211 sprayed onto the cavity side wall forms a working medium flow area, and the liquid working medium adhering to the cavity side wall can effectively slow down its falling speed. This is because the contact of liquid with the surface of solid can increase the frictional resistance, thereby slowing down the falling speed. In this way, the heat exchange time of the liquid working medium during the falling process is prolonged, thereby achieving the purpose of improving the heat exchange effect.

[0072] In some embodiments, as Figures 5 to 7As shown, based on the shape of the working fluid outlet pipe 122, the working fluid outlet pipe 122 includes a first part 1221 and a second part 1222 connected together. The first part 1221 extends outside the container body 112, is fixed to the upper end cap 113 and is used to connect with the compressor 200. The second part 1222 is located inside the receiving cavity 111 and is connected to the first part 1221. The second part 1222 is U-shaped, that is, the second part 1222 is a bend, so it is more difficult for the liquid working fluid in the receiving cavity 111 to flow into the second part 1222 to the compressor 200, which can enhance the anti-backflow effect of the gas-liquid separator 100.

[0073] Specifically, the second part 1222 includes at least two vertical portions 1222b extending in the vertical direction of the gas-liquid separator 100 and a bend 1222c connecting two adjacent vertical portions 1222b. Providing at least two vertical portions 1222b can increase the flow path of the working fluid entering the pipe, thereby providing more heat exchange time and a larger heat exchange area.

[0074] In some embodiments, such as Figure 6 and Figure 7 As shown, the working fluid outlet pipe 122, located within the receiving cavity 111 near the bottom of the tank 110, has at least one oil return hole 1223. In the gas-liquid separator 100, the separated and accumulated liquid working fluid contains dissolved oil. If the oil return hole 1223 is not provided, the lubricating oil in the compressor 200 will decrease, and the amount of lubricating oil deposited in the gas-liquid separator 100 will increase. Therefore, it is necessary to return the oil to the compressor 200 to ensure the oil quantity in the compressor 200 and the oil supply to the scroll section. Providing at least one oil return hole 1223 allows the oil-dissolved liquid working fluid to return to the compressor 200 through other paths. It is understandable that the oil return hole 1223 is located on the second part 1222 of the working fluid outlet pipe 122 near the bottom of the tank 110, which facilitates the oil falling back to the bottom wall of the receiving cavity 111 by gravity during the gas discharge process of the working fluid outlet pipe 122.

[0075] In some embodiments, the gas-liquid separator 100 further includes a support assembly 115, which can be welded to the lower end cap 114 or the container body 112. The support assembly 115 is located near the bottom of the tank 110, which can lower the center of gravity of the entire tank 110 and enhance its stability when fixed to the casing of the outdoor unit 10.

[0076] For example, the support assembly 115 includes four mounting legs that are circumferentially welded to the container body 112, thereby enhancing the structural stability of the container body 112, distributing the weight of the tank 110 and possible vibration loads more evenly, and reducing the pressure on the casing of the outdoor unit 10.

[0077] The application also proposes a control method for the heat pump system 1 as described above, the specific structure of which is referred to the above embodiments. Please refer to Figure 2 , Figure 3 and Figure 8 , the control method comprises the following steps:

[0078] Collecting the outdoor air temperature t1 and humidity parameters, setting the preset values t3 and t4 of the fin temperature of the evaporator 500, in a specific embodiment of the application, the preset values t3 and t4 are 0℃, judging whether the evaporator 500 has the possibility of frosting according to the collected outdoor air temperature t1 and humidity parameters, when t1 is less than or equal to 0℃, it can be judged that the evaporator 500 has the possibility of frosting;

[0079] If there is the possibility of frosting, the fin temperature t2 of the evaporator 500 is collected, and it is judged whether the fin temperature t2 of the evaporator 500 is greater than the preset value t3, if there is no possibility of frosting, i.e. t1 is greater than 0℃, the electric control system controls the first stop valve 610 to open, the second stop valve 620 and the defrosting bypass valve 630 to close, so as to run the heating mode;

[0080] If the fin temperature t2 of the evaporator 500 is less than or equal to the preset value t3, the electric control system controls the first stop valve 610 to close, the second stop valve 620 and the defrosting bypass valve 630 to open, so as to run the defrosting mode, if the fin temperature t2 of the evaporator 500 is greater than the preset value t3, the electric control system controls the first stop valve 610 to open, the second stop valve 620 and the defrosting bypass valve 630 to close, so as to continue to run the heating mode;

[0081] After running the defrosting mode, the fin temperature t5 of the evaporator 500 is collected after a preset time t, and it is judged whether the fin temperature t5 of the evaporator 500 is greater than the preset value t4;

[0082] If the fin temperature t5 of the evaporator 500 is less than or equal to the preset value t4, the electric control system controls the first stop valve 610 to close, the second stop valve 620 and the defrosting bypass valve 630 to open, so as to continue to run the defrosting mode, if the fin temperature t5 of the evaporator 500 is greater than the preset value t4, the electric control system controls the first stop valve 610 to open, the second stop valve 620 and the defrosting bypass valve 630 to close, so as to run the heating mode.

[0083] In some embodiments, the way of collecting the outdoor air temperature and humidity includes but is not limited to using sensors, thermometers and other devices, at this time, the temperature and humidity are collected by using sensors, the sensors can be temporarily placed by technicians at any position of the outdoor unit 10 of the heat pump system 1, temperature measurement values are obtained in these positions, and data is transmitted to the processor. Of course, the collection method can also be through weather monitoring, collecting weather forecasts, etc.

[0084] The electronic control system can comprise a cloud computing module with hardware (e.g. processor and / or memory) and software capable of performing the functions described below, in which configuration the electronic control system can acquire weather monitoring and / or weather forecasts via, for example, an internet, Bluetooth or cellular connection. When the electronic control system is provided with a processor, the collected temperature and humidity parameters can be processed and control instructions can be outputted to switch the operating mode of the heat pump system 1. The processor can also communicate with a server, which can receive data from the sensors, for example, through a network connection or a cellular network. The processor can receive data from the sensors on demand, intermittently or in real time. The processor can be located on a portable computing device of a contractor or technician, such as a laptop, tablet, smartphone or other device, or within the house or building in which the heat pump system 1 is installed, for example, in a thermostat or control module for the heat pump system 1.

[0085] The same or similar reference numerals in the drawings of the embodiments correspond to the same or similar components; in the description of the present application, it is understood that if the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right" and the like are based on the orientations or positional relationships shown in the drawings, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationships in the drawings are only used for exemplary illustration and cannot be understood as a limitation on the present application, for those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0086] The above is only a preferred embodiment of the present application and does not limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A gas-liquid separator applied to a heat pump system, characterized in that, include: The tank body has an internal cavity for receiving contents; The working fluid tube assembly includes a working fluid inlet pipe, a working fluid outlet pipe, and a high-pressure gas pipe that are spaced apart from each other on the tank body. A portion of the working fluid inlet pipe is located outside the tank body, and another portion is located inside the receiving cavity and is used to connect to the receiving cavity. A portion of the working fluid outlet pipe is located outside the tank body, and another portion is located inside the receiving cavity and is used to connect to the receiving cavity. The high-pressure gas pipe passes through the tank body, and both ends are located outside the tank body. as well as A heat exchange assembly is disposed within the receiving cavity and on the section of the high-pressure gas pipe located within the receiving cavity. The heat exchange assembly includes a partition and multiple heat exchange plates. The partition is disposed within the high-pressure gas pipe and divides the interior of the high-pressure gas pipe to form an inlet pipe section and an outlet pipe section. The multiple heat exchange plates are connected to the outer wall of the high-pressure gas pipe and are arranged around the high-pressure gas pipe. An airflow channel is provided within each heat exchange plate, and the airflow channel connects the inlet pipe section and the outlet pipe section.

2. The gas-liquid separator of claim 1, wherein, The heat exchange plates are radially distributed along the high-pressure gas pipe.

3. The gas-liquid separator of claim 1, wherein, The airflow channel includes multiple parallel-connected intake microchannels, a collection channel, and multiple parallel-connected exhaust microchannels. The multiple intake microchannels connect the intake pipe section and the collection channel, and the multiple exhaust microchannels connect the collection channel and the exhaust pipe section.

4. The gas-liquid separator of claim 3, wherein, The vent pipe section passes through the side wall or bottom wall of the tank and extends out of the tank.

5. A gas-liquid separator according to any one of claims 2 to 4, wherein The working fluid inlet pipe has an inlet outlet located within the receiving cavity, wherein the inlet outlet is located above the heat exchange assembly.

6. The gas-liquid separator of claim 5, wherein, The inlet and outlet pipes are positioned facing the inner wall of the tank.

7. The gas-liquid separator of claim 5, wherein The working fluid outlet pipe has an outlet inlet located within the receiving cavity, the outlet inlet being adjacent to the top of the tank and positioned above the inlet outlet.

8. The gas-liquid separator of any one of claims 1 to 4, wherein, The tank includes a container body and an upper cover connected together. The container body and the upper cover enclose the receiving cavity. The working fluid inlet pipe and the working fluid outlet pipe are both fixedly installed on the upper cover. The high-pressure gas pipe passes through the upper cover and the container body.

9. A heat pump system, characterized by, The system includes an outdoor unit and a hydraulic module connected by pipes. The outdoor unit includes a compressor, an air cooler, a regenerator, an evaporator, and a gas-liquid separator as described in any one of claims 1 to 8, all connected by pipes. The hydraulic module includes the air cooler. The compressor has an exhaust port and a return port. A first pipeline and a second pipeline are connected in parallel at the exhaust port of the compressor. The exhaust port is connected to the inlet of the air cooler through the first pipeline. The exhaust port is connected to the inlet of the high-pressure gas pipe through the second pipeline. The outlet of the high-pressure gas pipe is connected to the inlet of the air cooler. The return port is connected to the outlet of the working fluid outlet pipe. The outlet of the air cooler is connected to the first inlet of the regenerator, the first outlet of the regenerator is connected to the inlet of the evaporator, the outlet of the evaporator is connected to the second inlet of the regenerator, and the second outlet of the regenerator is connected to the inlet of the working fluid inlet pipe of the gas-liquid separator. The outdoor unit further comprises a valve assembly and a throttling assembly, the valve assembly comprises a first stop valve, a second stop valve and a defrost bypass valve, the throttling assembly comprises a throttling valve and a defrost capillary, the first stop valve is arranged on the first pipeline, the second stop valve is arranged on the second pipeline, and the throttling valve is arranged between the first outlet of the heat regenerator and the air inlet of the evaporator; The outdoor unit further comprises a bypass, the bypass connects the air outlet of the compressor and the air inlet of the evaporator, and the defrost bypass valve and the defrost capillary are arranged in series on the bypass.

10. A control method for the heat pump system as claimed in claim 9, characterized in that the steps Comprise: S1: collect outdoor air temperature t1 and humidity parameters, set evaporator fin temperature preset value t3, t4, according to the collected outdoor air temperature t1 and humidity parameters, judge whether the evaporator has the possibility of frosting; S2: if there is a possibility of frosting, collect the evaporator fin temperature t2, and judge whether the evaporator fin temperature t2 is greater than the preset value t3, if there is no possibility of frosting, control the first stop valve to open, and the second stop valve and the defrost bypass valve are closed to run the heating mode; S3: if the evaporator fin temperature t2 is less than or equal to the preset value t3, control the first stop valve to close, the second stop valve and the defrost bypass valve are opened to run the defrosting mode, if the evaporator fin temperature t2 is greater than the preset value t3, control the first stop valve to open, the second stop valve and the defrost bypass valve are closed to continue running the heating mode.

11. The control method according to claim 10, characterized by, After running the defrosting mode, after a preset time t, collect the evaporator fin temperature t5, and judge whether the evaporator fin temperature t5 is greater than the preset value t4; If the evaporator fin temperature t5 is less than or equal to the preset value t4, control the first stop valve to close, the second stop valve and the defrost bypass valve are opened to continue running the defrosting mode, if the evaporator fin temperature t5 is greater than the preset value t4, control the first stop valve to open, the second stop valve and the defrost bypass valve are closed to run the heating mode.

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