Air conditioning unit and supercooling structure thereof

Abstract

The invention provides an air conditioning unit and a supercooling structure thereof, and the supercooling structure comprises a gas-liquid separator which is provided with a shell and a supercooling pipeline arranged in the shell; the liquid inlet pipeline and the liquid outlet pipeline are respectively communicated with two ends of the cooling pipeline, the liquid inlet pipeline can be used for communicating with an outlet of the condenser, and the liquid outlet pipeline can be used for communicating with an inlet of the evaporator; the air inlet pipeline and the air outlet pipeline are both communicated with the shell; the first end of the air inlet pipeline can be used for being communicated with an outlet of the evaporator, the second end of the air inlet pipeline is suspended in the shell, the first end of the air outlet pipeline can be used for being communicated with an inlet of the compressor, the second end of the air outlet pipeline is suspended in the shell, and the lowest position of the supercooling pipeline is higher than the lowest position of the air outlet pipeline and lower than the second end of the air outlet pipeline. Therefore, the gas-liquid separator can utilize the low-temperature gas-state refrigerant flowing out of the evaporator to supercool the high-pressure liquid-state refrigerant flowing out of the condenser, so that the unit refrigerating capacity of the refrigerating system is improved, and the refrigerating energy efficiency of the refrigerating system is improved.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioning, and in particular to an air conditioning unit and a supercooling structure thereof. Background Art

[0002] With the development of cities, the passenger capacity of urban rail transit such as subways and trams has greatly increased. Air conditioners, as electrical appliances that provide a comfortable environment for urban rail transit, have a long usage time and are used in large quantities, and their energy consumption is huge. Therefore, improving the energy efficiency of air conditioners is of great significance to reducing costs and optimizing the energy structure.

[0003] In the process of implementing the present invention, the inventors found that there are at least the following problems in the prior art:

[0004] Although the existing air-conditioning systems are becoming more and more energy efficient, they rely more on high-efficiency compressors, and the heat in the air-conditioning system cannot be used reasonably and effectively. Although some technologies utilize the cold or heat in the air-conditioning system, many components are introduced, which not only leads to increased cost investment, but also causes the entire air-conditioning system to occupy more space and is not easy to install due to the increase in the number of introduced components. Summary of the invention

[0005] In view of this, the present application provides an air-conditioning unit and a supercooling structure thereof, which are beneficial to improving the unit cooling capacity of the system, thereby improving the cooling energy efficiency.

[0006] In order to achieve the above objectives, this application provides the following technical solutions:

[0007] A supercooling structure, comprising:

[0008] A gas-liquid separator comprises a shell and a supercooling pipeline arranged in the shell;

[0009] The liquid inlet pipeline and the liquid outlet pipeline are connected to the two ends of the subcooling pipeline respectively, the liquid inlet pipeline can be used to connect to the outlet of the condenser, and the liquid outlet pipeline can be used to connect to the inlet of the evaporator;

[0010] An air inlet pipeline and an air outlet pipeline are both connected to the shell; the first end of the air inlet pipeline can be used to connect with the outlet of the evaporator, and the second end of the air inlet pipeline is suspended in the shell; the first end of the air outlet pipeline can be used to connect with the inlet of the compressor, and the second end of the air outlet pipeline is suspended in the shell; the lowest position of the subcooling pipeline is higher than the lowest position of the air outlet pipeline and lower than the second end of the air outlet pipeline.

[0011] Optionally, an oil return hole is provided on the air outlet pipeline, and the oil return hole is lower than the second end of the air outlet pipeline.

[0012] Optionally, the oil return hole is arranged at the lowest position of the air outlet pipeline.

[0013] Optionally, the first end of the gas outlet pipeline is higher than the highest position of the supercooling pipeline, and the middle part of the gas outlet pipeline passes through the supercooling pipeline.

[0014] Optionally, the subcooling pipeline is at least partially higher than the second end of the outlet pipeline and lower than the second end of the inlet pipeline, so that the refrigerant between the second end of the inlet pipeline and the second end of the outlet pipeline can exchange heat through the subcooling pipeline.

[0015] Optionally, the lowest position of the supercooling pipeline is lower than the second end of the air outlet pipeline, and the highest position of the supercooling pipeline is higher than the second end of the air inlet pipeline.

[0016] Optionally,

[0017] The height difference between the second end of the air inlet pipeline and the second end of the air outlet pipeline is 0.3-0.5 times the total height of the supercooling pipeline;

[0018] and / or, the height difference between the second end of the air outlet pipeline and the bottom of the shell is 0.3-0.4 times the total height of the shell;

[0019] And / or, the height difference between the second end of the gas outlet pipeline and the lowest position of the supercooling pipeline is 0.3-0.5 times the total height of the supercooling pipeline.

[0020] Optionally,

[0021] The outlet pipe is provided with a temperature sensing device to sense the temperature of the refrigerant flowing out of the outlet pipe;

[0022] And / or, a liquid level device is provided on the shell to obtain the liquid level in the shell.

[0023] Optionally, it also includes:

[0024] The bypass pipeline is connected to the shell and can be used to connect to the outlet of the condenser. A first throttling element is arranged on the bypass pipeline to enable the refrigerant flowing out of the condenser to evaporate and absorb heat in the shell.

[0025] An air conditioning unit, comprising:

[0026] Evaporators, condensers and compressors;

[0027] The supercooling structure is configured as a supercooling structure as described in any of the above items;

[0028] The outlet of the compressor is connected to the inlet of the condenser, and the liquid outlet pipeline is connected to the inlet of the evaporator through a second throttling element.

[0029] Optionally, a four-way valve is also included, wherein the first interface and the third interface of the four-way valve are respectively connected to the outlet and the inlet of the compressor, and the second interface and the fourth interface of the four-way valve are respectively connected to the inlet of the condenser and the outlet of the evaporator, so as to switch the working states of the condenser and the evaporator through the four-way valve; and the liquid inlet pipeline and the bypass pipeline are connected to the outlet of the condenser through a third throttling element.

[0030] Compared with the prior art, the technical solution provided by this application has at least the following beneficial effects:

[0031] The air conditioning unit and its supercooling structure provided by the present application, the gas-liquid separator can use the low-temperature gaseous refrigerant flowing out of the evaporator to supercool the high-pressure liquid refrigerant flowing out of the condenser, thereby improving the unit refrigeration capacity of the refrigeration system, and then improving the refrigeration energy efficiency of the refrigeration system. After the gaseous refrigerant flows in from the second end of the gas outlet pipeline, it can still exchange heat with the liquid refrigerant in the supercooling pipeline, and finally flows out from the first end of the gas outlet pipeline, which can effectively ensure the stability and uniform temperature of the gaseous refrigerant flowing out of the gas outlet pipeline, so that the gaseous refrigerant flowing into the inlet of the compressor is safe and stable, which is conducive to improving the safety and stability of the compressor. Due to the setting of the supercooling pipeline, the high-temperature liquid refrigerant in the supercooling pipeline will not only exchange heat with the low-temperature gaseous refrigerant in the shell during the supercooling process, but also exchange heat with the liquid refrigerant in the shell, so that the liquid refrigerant at the bottom of the shell is heated and evaporated to form a gaseous refrigerant (the liquid refrigerant at the bottom of the shell evaporates and absorbs heat and completes the supercooling of the refrigerant in the supercooling pipeline), thereby reducing the mixed liquid at the bottom of the shell. At the same time, since the second end of the outlet pipe is higher than the lowest position of the subcooling pipe and the lowest position of the outlet pipe, the second end of the outlet pipe can be effectively prevented from being submerged in the mixed liquid at the bottom of the shell, thereby effectively avoiding liquid hammer caused by liquid return from the compressor, which is beneficial to improving the stability of the system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0033] Figure 1 A connection structure diagram of an air conditioning unit shown in some embodiments;

[0034] Figure 2A connection structure diagram of a supercooling structure according to some embodiments.

[0035] In the figure: 1. condenser; 2. evaporator; 3. compressor; 4. gas-liquid separator; 5. four-way valve; 6. first drying filter; 7. first throttling element; 8. temperature sensing device; 9. liquid level device; 10. second drying filter; 11. second throttling element; 12. third throttling element; 41. shell; 42. subcooling pipeline; 43. outlet pipeline; 44. inlet pipeline; 45. bypass pipeline; 46. oil return hole. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] like Figure 1-Figure 2 As shown, an embodiment of the present application provides a supercooling structure, including a gas-liquid separator 4, an air outlet pipeline 43, an air inlet pipeline 44, a liquid inlet pipeline, a liquid outlet pipeline and a bypass pipeline 45.

[0038] The gas-liquid separator 4 includes a shell 41 and a subcooling pipeline 42. The subcooling pipeline 42 is arranged in the shell 41. For example, a liquid inlet and a liquid outlet are provided on the shell 41. The first end and the second end of the subcooling pipeline 42 are respectively connected to the liquid inlet and the liquid outlet, so that the outer wall of the subcooling pipeline 42 is exposed to the inside of the shell 41, and the two ports of the subcooling pipeline 42 can be connected to the outside of the shell 41, so as to realize heat exchange in the shell 41 through the pipe wall of the subcooling pipeline 42.

[0039] Among them, the air outlet pipeline 43, the air inlet pipeline 44 and the bypass pipeline 45 are all connected to the shell 41, the air inlet pipeline 44 can be used to connect to the outlet of the evaporator 2, and the air outlet pipeline 43 can be used to connect to the inlet (also known as the air intake or air intake) of the compressor 3; the liquid inlet pipeline and the liquid outlet pipeline are respectively connected to the two ends of the cold pipeline 42, the liquid inlet pipeline can be used to connect to the outlet of the condenser 1, the liquid outlet pipeline can be used to connect to the inlet of the evaporator 2, and the bypass pipeline 45 can be used to connect to the outlet of the condenser 1.

[0040] When in use, the supercooling structure is connected to the air-conditioning system, the outlet (also called the exhaust port or the air outlet) of the compressor 3 is connected to the inlet of the condenser 1, the first end of the supercooling pipeline 42 is connected to the outlet of the condenser 1 through the liquid inlet pipeline, the second end of the supercooling pipeline 42 is connected to the inlet of the evaporator 2 through the liquid outlet pipeline, and the shell 41 is connected to the outlet of the evaporator 2 and the inlet of the compressor 3 through the air inlet pipeline 44 and the air outlet pipeline 43 respectively, so that the compressor 3, the condenser 1, the gas-liquid separator 4 and the evaporator 2 are connected to form a refrigerant circuit. In the refrigerant circuit, the refrigerant passes through the compressor 3, the condenser 1, the gas-liquid separator 4, the evaporator 2, the gas-liquid separator 4 in turn, and returns to the compressor 3 to complete a cycle. Since the refrigerant circuit passes through the gas-liquid separator 4 twice, the liquid refrigerant flowing out of the condenser 1 and the gaseous refrigerant flowing out of the evaporator 2 can be heat exchanged in the shell 41.

[0041] The outlet of the condenser 1 is connected to the shell 41 through the bypass line 45, and the bypass line 45 is provided with a first throttling element 7. Under the action of the first throttling element 7, the liquid refrigerant flowing out of the condenser 1 and diverted to the bypass line 45 can be converted into a gas-liquid mixed state or a gaseous refrigerant, and evaporates and absorbs heat in the shell 41, so as to cool the refrigerant in the shell 41. Among them, the first throttling element 7 can be set as an electronic expansion valve or a thermal expansion valve, so that the opening of the first throttling element 7 can be regulated by the control system, and the regulation basis can be a comprehensive factor such as the temperature of the refrigerant flowing out of the shell.

[0042] In this way, the gas-liquid separator 4 can use the low-temperature gaseous refrigerant flowing out of the evaporator 2 to supercool the high-pressure liquid refrigerant flowing out of the condenser 1, thereby increasing the unit refrigeration capacity of the refrigeration system, and then improving the refrigeration efficiency of the refrigeration system; at the same time, the liquid refrigerant in the bypass pipeline 45 will flow into the gas-liquid separator 4 under the action of throttling, and evaporate and absorb heat in the shell 41 to maintain the low-pressure gaseous refrigerant in a reasonable temperature rise range. Moreover, due to the supercooling of the gas-liquid separator 4, the pipeline to the evaporator 2 is all liquid, rather than a gas-liquid two-phase flow, which can effectively avoid the noise generated in the pipeline due to the gas-liquid two-phase flow, and has a good noise reduction effect.

[0043] Specifically, the bypass line 45 is connected to a first position of the shell 41, and the first position is higher than the lowest position of the supercooling line 42 and lower than the highest position of the supercooling line 42, so that the liquid refrigerant flowing into the shell 41 from the bypass line 45 directly corresponds to the middle position of the supercooling line 42. In combination, since the second end of the air intake line 44 is suspended in the middle position of the supercooling line 42, when the temperature of the gaseous refrigerant in the shell 41 rises too high, the liquid refrigerant flowing out of the bypass line 45 can be directly mixed with the gaseous refrigerant flowing out of the air intake line 44 to cool down, and the cooling efficiency is relatively high, which is beneficial for coping with sudden temperature changes.

[0044] In this solution, the air inlet pipe 44 and the air outlet pipe 43 partially extend into the interior of the shell 41, so that the first ends of the air outlet pipe 43 and the air inlet pipe 44 are located outside the shell 41, and the second ends are located inside the shell 41. When in use, the first end of the air inlet pipe 44 can be used to communicate with the outlet of the evaporator 2, and the second end of the air inlet pipe 44 is suspended in the shell 41; the first end of the air outlet pipe 43 can be used to communicate with the inlet of the compressor 3, and the second end of the air outlet pipe 43 is suspended in the shell 41. In this way, through the outlet of the air outlet pipe 43 and the intake of the air inlet pipe 44, the gaseous refrigerant between the second end of the air outlet pipe 43 and the second end of the air inlet pipe 44 can be evenly distributed in the shell 41, which is conducive to heat exchange with the supercooling pipe 42.

[0045] Among them, the second end of the gas outlet pipeline 43 is higher than the lowest position of the supercooling pipeline 42, and the lowest position of the supercooling pipeline is higher than the lowest position of the gas outlet pipeline and lower than the second end of the gas outlet pipeline, so that the second end of the gas outlet pipeline 43 is suspended and arranged in the middle position of the supercooling pipeline 42. In a specific scheme, the first end of the gas outlet pipeline is higher than the highest position of the supercooling pipeline, and the middle part of the gas outlet pipeline passes through the supercooling pipeline, so as to facilitate the gaseous refrigerant in the gas outlet pipeline 43 and the liquid refrigerant in the supercooling pipeline 42 to fully exchange heat. For example, the gas outlet pipeline 43 is set to a fishhook shape, and the gas outlet pipeline 43 extends downward from the first end until it is lower than the lowest position of the supercooling pipeline 42, and then extends upward to the middle part of the supercooling pipeline 42, so that the gas outlet pipeline 43 is in the middle part of the shell 41, and the supercooling pipeline 42 is distributed on the periphery of the gas outlet pipeline 43.

[0046] With such arrangement, after the gaseous refrigerant flows in from the second end of the air outlet pipe 43, it can still exchange heat with the liquid refrigerant in the supercooling pipe, and finally flow out from the first end of the air outlet pipe 43. This can ensure the stability and uniform temperature of the gaseous refrigerant flowing out of the air outlet pipe 43, making the gaseous refrigerant flowing into the inlet of the compressor 3 safe and stable, which is beneficial to improving the safety and stability of the compressor 3.

[0047] It should be noted that during operation, the refrigeration oil in the compressor will be brought into the shell 41 of the gas-liquid separator by the refrigerant, so that a mixed liquid of refrigeration oil and refrigerant exists at the bottom of the shell 41. Due to the setting of the supercooling pipeline 42, the high-temperature liquid refrigerant in the supercooling pipeline 42 will not only exchange heat with the low-temperature gaseous refrigerant in the shell 41, but also exchange heat with the liquid refrigerant in the shell 41 during the supercooling process, so that the liquid refrigerant at the bottom of the shell 41 is heated and evaporated to form a gaseous refrigerant (the liquid refrigerant at the bottom of the shell 41 evaporates and absorbs heat and completes the supercooling of the refrigerant in the supercooling pipeline 42), thereby reducing the mixed liquid at the bottom of the shell 41. At the same time, since the second end of the air outlet pipeline 43 is higher than the lowest position of the supercooling pipeline 42 and the lowest position of the air outlet pipeline 43, the second end of the air outlet pipeline 43 can be prevented from being submerged by the mixed liquid at the bottom of the shell 41, thereby effectively avoiding the liquid hammer phenomenon caused by the compressor liquid return, which is conducive to improving the stability of the system operation.

[0048] In some embodiments, an oil return hole 46 is provided on the gas outlet pipeline 43, and the oil return hole 46 is lower than the second end of the gas outlet pipeline 43. In this way, when the liquid level of the refrigerant oil at the bottom of the shell 41 exceeds the oil return hole 46, the refrigerant oil will flow into the gas outlet pipeline 43 through the oil return hole 46, and the refrigerant oil and the gaseous refrigerant in the gas outlet pipeline 43 will mix and flow into the compressor, which can effectively avoid the situation of oil shortage in the compressor and make the operation of the whole system more reliable.

[0049] Specifically, the oil return hole 46 is disposed at the lowest position of the air outlet pipeline 43 so that the liquid level of the refrigerant oil in the shell 41 firstly exceeds the oil return hole 46 , thereby avoiding the compressor from lacking oil to the greatest extent.

[0050] It is understandable that the diameter of the oil return hole 46 is small and does not affect the air intake at the second end of the air outlet pipe 43, that is, when the refrigerant oil flows into the oil return hole 46, the second end of the air outlet pipe 43 still has a large air intake volume to avoid a large amount of liquid flowing into the inlet of the compressor.

[0051] In some embodiments, the subcooling pipeline 42 is at least partially higher than the second end of the gas outlet pipeline 43 and lower than the second end of the gas inlet pipeline 44, so that the refrigerant between the second end of the gas inlet pipeline 44 and the second end of the gas outlet pipeline 43 can pass through the subcooling pipeline 42 for heat exchange. For example, the middle of the subcooling pipeline 42 is between the second end of the gas outlet pipeline 43 and the second end of the gas inlet pipeline 44. For another example, the upper part or the lower part of the subcooling pipeline 42 is between the second end of the gas outlet pipeline 43 and the second end of the gas inlet pipeline 44. In this way, the area between the second end of the gas outlet pipeline 43 and the second end of the gas inlet pipeline 44 overlaps with the subcooling pipeline 42 in height, so that the gaseous refrigerant flowing out of the second end of the gas outlet pipeline 43 descends and is dispersed to the outer wall position of the subcooling pipeline 42. Since the flow path of the gaseous refrigerant in the shell passes through the outer wall of the subcooling pipeline 42, it is beneficial to improve the subcooling heat exchange effect of the subcooling pipeline 42 and the sensitivity of heat exchange.

[0052] In the preferred embodiment, the lowest position of the subcooling pipeline 42 is lower than the second end of the outlet pipeline 43, and the highest position of the subcooling pipeline 42 is higher than the second end of the inlet pipeline 44, so that the middle of the subcooling pipeline 42 is between the second end of the outlet pipeline 43 and the second end of the inlet pipeline 44. Since the middle of the subcooling pipeline 42 is far away from the first end and the second end of the subcooling pipeline 42, it is less affected by external environmental factors, which is conducive to accurate control of the heat exchange amount.

[0053] Specifically, the height difference between the second end of the outlet pipe 43 and the second end of the inlet pipe 44 is 0.3-0.5 times the total height of the supercooling pipe 42, and the specific ratio can be set to one third. In this way, the heat exchange effect of the gas-liquid separator 4 can be maintained within a reasonable range. When the gaseous refrigerant and the high-pressure liquid refrigerant fully exchange heat in the gas-liquid separator 4, it may cause the gaseous refrigerant in the shell 41 to rise too high. Although the liquid inlet of the bypass pipe 45 can maintain the upper limit of the suction temperature, the normal heat exchange in the gas-liquid separator 4 does not require the liquid inlet of the bypass pipe 45. The bypass pipe 45 mainly plays a role in protecting the normal operation of the system. When the second end of the outlet pipe 43 is too high, the gaseous refrigerant and the high-pressure liquid refrigerant exchange less heat in the gas-liquid separator 4, and the gaseous refrigerant flowing in from the inlet pipe 44 has already flowed out from the outlet pipe 43 before it has time to exchange heat, and the coldness in the gaseous refrigerant cannot be reasonably utilized.

[0054] In addition, the height difference between the second end of the air outlet pipeline 43 and the bottom of the shell 41 is 0.3-0.4 times (preferably one third) of the total height of the shell 41. Alternatively, the height difference between the second end of the air outlet pipeline 43 and the lowest position of the supercooling pipeline 42 is 0.3-0.5 times (preferably one third) of the total height of the supercooling pipeline 42. In this way, it is beneficial to maintain the heat exchange effect of the gas-liquid separator 4 within a reasonable range. When the gaseous refrigerant and the high-pressure liquid refrigerant fully exchange heat in the gas-liquid separator 4, the gaseous refrigerant in the shell 41 may rise too high. Although the liquid inlet of the bypass pipeline 45 can maintain the upper limit of the suction temperature, the normal heat exchange in the gas-liquid separator 4 does not require the liquid inlet of the bypass pipeline 45. The bypass pipeline 45 mainly plays a role in protecting the normal operation of the system. When the second end of the air outlet pipe 43 is too high, the heat exchange between the gaseous refrigerant and the high-pressure liquid refrigerant in the gas-liquid separator 4 is less, and the gaseous refrigerant flowing in from the air inlet pipe 44 flows out from the air outlet pipe 43 before it has time to exchange heat, and the coldness in the gaseous refrigerant cannot be reasonably utilized.

[0055] It should be noted that the above ratio can be determined in combination with the diameter of the subcooling pipeline 42, the size of the shell 41, and the connection position of the bypass pipeline 45, and the specific value is determined according to design requirements and design conditions.

[0056] In some preferred embodiments, the subcooling pipeline 42 includes a plurality of capillary branches, for example, three, four or five capillary branches are provided. The two ends of the plurality of capillary branches are respectively connected to the liquid inlet pipeline and the liquid outlet pipeline, so that the liquid refrigerant flowing in from the liquid inlet pipeline is first dispersed into the plurality of capillary branches, and after heat exchange through the plurality of capillary branches, it is merged into the liquid outlet pipeline and flows into the evaporator 2. In this way, the subcooling heat exchange effect of the subcooling pipeline 42 can be improved by the plurality of parallel capillary branches, so as to accurately and sensitively control the heat exchange.

[0057] The bypass line 45 is provided with a first throttling element 7 and a drying filter (i.e. Figure 2 The first drying filter 6 is arranged away from the shell 41 relative to the first throttling element 7. In this way, before the liquid refrigerant enters the shell 41, the impurities contained in the liquid refrigerant can be removed to prevent the first throttling element 7 on the bypass line 45 from being blocked, and to avoid the accumulation of impurities in the shell 41, which is conducive to improving the service life and stability of the product.

[0058] A temperature sensing device 8 is provided at the first end of the air outlet pipe 43. The temperature sensing device 8 is used to sense the temperature of the refrigerant flowing out of the air outlet pipe 43. For example, the first end of the air outlet pipe 43 protrudes from the outside of the shell 41, and the temperature sensing device 8 is provided on one end of the air outlet pipe 43 that is located outside the shell 41. By detecting the temperature of the outflowing gaseous refrigerant, it is beneficial to accurately and stably control the temperature inside the shell 41.

[0059] A liquid level device 9 is provided on the shell 41 for obtaining the liquid level (such as refrigerant liquid level or oil level) in the shell 41 , and then obtaining the gas-liquid separation state inside the shell 41 , which is conducive to accurate regulation and control of the gas-liquid separator 4 .

[0060] The present application also provides an air conditioning unit, including a condenser 1, an evaporator 2, a compressor 3 and a supercooling structure, and the supercooling structure is the supercooling structure in the above embodiment. In this way, the gas-liquid separator 4 can use the low-temperature gaseous refrigerant flowing out of the evaporator 2 to supercool the high-pressure liquid refrigerant flowing out of the condenser 1, thereby improving the unit refrigeration capacity of the refrigeration system, and then improving the refrigeration energy efficiency of the refrigeration system; at the same time, the liquid refrigerant in the bypass line 45 will flow into the gas-liquid separator 4 under the action of throttling, and evaporate and absorb heat in the shell 41 to maintain the low-pressure gaseous refrigerant in a reasonable temperature rise range. Moreover, due to the supercooling of the gas-liquid separator 4, the pipeline to the evaporator 2 is all liquid, rather than a gas-liquid two-phase flow, which can avoid the noise generated in the pipeline due to the gas-liquid two-phase flow, and play a noise reduction effect.

[0061] In addition, in order to ensure the stable operation of the air conditioning unit, a low-pressure switch is provided on the pipeline between the housing 41 and the inlet of the compressor 3 (such as the air outlet pipeline 43), a low-pressure sensor is provided on the pipeline between the housing 41 and the outlet of the evaporator 2 (such as the air intake pipeline 44), a one-way valve, a temperature sensor, a high-pressure switch and a high-pressure sensor are provided on the pipeline between the outlet of the compressor 3 and the inlet of the condenser 1 in sequence, and a second drying filter 10 and a second throttling element 11 are provided on the pipeline between the liquid outlet pipeline and the inlet of the evaporator 2 (or the liquid outlet pipeline). At the same time, the evaporator 2 is adapted to be equipped with an evaporation fan, and the condenser 1 is adapted to be equipped with a condensation fan.

[0062] like Figure 1The solid arrow in the figure is the flow direction of the refrigerant during refrigeration. During the refrigeration process, the refrigerant is compressed by the compressor 3 and becomes a high-temperature and high-pressure gaseous refrigerant, and then flows to the condenser 1 to condense into a normal-temperature and high-pressure liquid refrigerant; the refrigerant continues to flow into the supercooling pipeline 42 of the gas-liquid separator 4; at the same time, the low-temperature and low-pressure gaseous refrigerant flowing out of the evaporator 2 in the previous process flows into the shell 41 of the gas-liquid separator 4 and exchanges heat with the high-pressure liquid refrigerant in the supercooling pipeline 42. When the shell 41 is overheated and the temperature of the low-pressure gaseous refrigerant rises too high, the liquid refrigerant in the bypass pipeline 45 will enter the shell 41 under the action of the first throttling element 7, and the liquid refrigerant evaporates and absorbs heat in the shell 41, thereby maintaining the low-pressure gaseous refrigerant in a reasonable temperature rise range. After the high-pressure liquid refrigerant in the subcooling pipeline 42 is subcooled, it enters the evaporator 2 for evaporation and heat absorption under the action of the second throttling element 11, and then the low-temperature and low-pressure gaseous refrigerant flows into the shell 41 of the gas-liquid separator 4 to subcool the high-pressure liquid refrigerant of the next cycle. After the subcooling heat exchange, it is compressed into a high-temperature and high-pressure gaseous refrigerant by the compressor 3, thereby completing a refrigeration cycle. In this way, through the design of the gas-liquid separator 4, the gas-liquid separator 4 can not only perform gas-liquid separation, but also perform subcooling heat exchange on the refrigerant.

[0063] The air conditioning unit also includes a four-way valve 5, which has a first interface, a second interface, a third interface and a fourth interface. When the four-way valve 5 is in the first state, the first interface and the second interface are connected, and the third interface and the fourth interface are connected. When the four-way valve 5 is in the second state, the first interface and the fourth interface are connected, and the second interface and the third interface are connected. Among them, the first interface of the four-way valve 5 is connected to the outlet of the compressor 3, the third interface is connected to the inlet of the compressor 3, the second interface of the four-way valve 5 is connected to the inlet of the condenser 1, and the fourth interface is connected to the outlet of the evaporator 2. In this way, by switching the state of the four-way valve 5, the refrigerant compressed by the compressor 3 can flow to the evaporator 2 or the condenser 1, thereby switching the working states of the condenser 1 and the evaporator 2, and realizing the switching of the cooling and heating states of the evaporator 2.

[0064] Here, the outlet of the condenser 1 is connected to the liquid inlet pipeline and the bypass pipeline 45 through the third throttling element 12, which plays the role of a connecting valve during cooling and plays the role of a throttling valve during heating.

[0065] It should be noted that the inlet and outlet of the condenser 1 and the inlet and outlet of the evaporator 2 in this document are descriptions of the air-conditioning unit in the cooling state, that is, in the cooling state, the refrigerant flows from the inlet to the outlet. On the contrary, in the heating state, the working states of the condenser 1 and the evaporator 2 are interchanged so that the refrigerant flows from the outlet to the inlet. In particular, due to the setting of the four-way valve 5, the refrigerant flows from the inlet of the compressor 3 to the outlet of the compressor 3 in both the cooling and heating states.

[0066] like Figure 1 The dotted arrow in the figure is the flow direction of the refrigerant during heating. During the heating process, the refrigerant is compressed by the compressor 3 and becomes a high-temperature and high-pressure gaseous refrigerant, and then enters the evaporator 2 under the reversing action of the four-way valve 5; after condensation and heating by the evaporator 2, it becomes a liquid refrigerant at room temperature, and enters the subcooling pipeline 42 of the gas-liquid separator 4 after passing through the second throttling element 11 (at this time, the second throttling element 11 is used as a stop valve, no throttling is performed, and the valve step is opened to the maximum), and the high-pressure liquid refrigerant flows in the subcooling pipeline 42 of the gas-liquid separator 4 in the reverse direction; at the same time, the low-temperature and low-pressure gaseous refrigerant flowing out of the condenser 1 in the previous process flows into the shell 41 of the gas-liquid separator 4, and exchanges heat with the high-pressure liquid refrigerant in the subcooling pipeline 42. After the heat exchange, the liquid refrigerant is throttled by the third throttling element 12, enters the condenser 1 for heat exchange, and finally returns to the shell 41 of the gas-liquid separator 4 through the four-way valve 5, thereby completing a heating cycle.

[0067] In this way, the first throttling element 7 on the bypass line 45 does not work during heating. Due to the increased supercooling of the gas-liquid separator 4, the temperature of the gaseous refrigerant in the shell 41 increases, which effectively avoids the low-pressure switch from not working due to low temperature. At the same time, the low pressure value of the gaseous refrigerant is increased, which is beneficial to increase the unit heating capacity, thereby improving the heating energy efficiency of the system, and by adjusting the high and low pressures of the system, it is beneficial to maintain the stable operation of the system.

[0068] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0069] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0070] It should also be noted that in the apparatus, device and method of the present application, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0071] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0072] It should be understood that the qualifiers "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only used to more clearly explain the technical solutions and cannot be used to limit the scope of protection of the present application.

[0073] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A supercooling structure, characterized in that: include: A gas-liquid separator comprises a shell and a supercooling pipeline arranged in the shell; The liquid inlet pipeline and the liquid outlet pipeline are connected to the two ends of the subcooling pipeline respectively, the liquid inlet pipeline can be used to connect to the outlet of the condenser, and the liquid outlet pipeline can be used to connect to the inlet of the evaporator; An air inlet pipeline and an air outlet pipeline are both connected to the shell; the first end of the air inlet pipeline can be used to connect with the outlet of the evaporator, and the second end of the air inlet pipeline is suspended in the shell; the first end of the air outlet pipeline can be used to connect with the inlet of the compressor, and the second end of the air outlet pipeline is suspended in the shell; the lowest position of the subcooling pipeline is higher than the lowest position of the air outlet pipeline and lower than the second end of the air outlet pipeline.

2. The supercooling structure according to claim 1, characterized in that: The air outlet pipeline is provided with an oil return hole, and the oil return hole is lower than the second end of the air outlet pipeline.

3. The supercooling structure according to claim 2, characterized in that: The oil return hole is arranged at the lowest position of the air outlet pipeline.

4. The supercooling structure according to claim 1, characterized in that: The first end of the gas outlet pipeline is higher than the highest position of the supercooling pipeline, and the middle part of the gas outlet pipeline passes through the supercooling pipeline.

5. The supercooling structure according to claim 1, characterized in that: The subcooling pipeline is at least partially higher than the second end of the outlet pipeline and lower than the second end of the inlet pipeline, so that the refrigerant between the second end of the inlet pipeline and the second end of the outlet pipeline can exchange heat through the subcooling pipeline.

6. The supercooling structure according to claim 5, characterized in that: The lowest position of the supercooling pipeline is lower than the second end of the air outlet pipeline, and the highest position of the supercooling pipeline is higher than the second end of the air inlet pipeline.

7. The supercooling structure according to claim 5, characterized in that: The height difference between the second end of the air inlet pipeline and the second end of the air outlet pipeline is 0.3-0.5 times the total height of the supercooling pipeline; and / or, the height difference between the second end of the air outlet pipeline and the bottom of the shell is 0.3-0.4 times the total height of the shell; And / or, the height difference between the second end of the air outlet pipeline and the lowest position of the supercooling pipeline is 0.3-0.5 times the total height of the supercooling pipeline.

8. The supercooling structure according to claim 1, characterized in that: The outlet pipe is provided with a temperature sensing device to sense the temperature of the refrigerant flowing out of the outlet pipe; And / or, a liquid level device is provided on the shell to obtain the liquid level in the shell.

9. The supercooling structure according to any one of claims 1 to 8, characterized in that: Also includes: The bypass pipeline is connected to the shell and can be used to connect to the outlet of the condenser. A first throttling element is arranged on the bypass pipeline to enable the refrigerant flowing out of the condenser to evaporate and absorb heat in the shell.

10. An air conditioning unit, characterized in that: include: Evaporators, condensers and compressors; The supercooling structure is configured as the supercooling structure according to any one of claims 1 to 9; The outlet of the compressor is connected to the inlet of the condenser, and the liquid outlet pipeline is connected to the inlet of the evaporator through a second throttling element.

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