A refrigeration system with automatic liquid return

Abstract

The application provides a refrigeration system with automatic liquid return, comprising an evaporator, a gas-liquid separator and an oil separator, the inside of the gas-liquid separator is communicated with the inside of the evaporator through a liquid return pipe, so that the liquid in the evaporator can be guided out to the gas-liquid separator; further comprising a gas return pipe, one end of the gas return pipe is communicated with the inside of the gas-liquid separator, and the other end is communicated with the inside of the oil separator, so that the gas separated in the gas-liquid separator can be guided into the oil separator through the gas return pipe, and the liquid at the bottom of the oil separator can also be returned to the gas-liquid separator through the gas return pipe. According to the application, the problem that the liquid is gathered in the lower part of the evaporator and / or the middle and lower part of the gas collecting header of the evaporator, which leads to the problem that the amount of refrigerant participating in the circulation in the system is too small and the heat exchange performance of the evaporator is affected, can be solved, and the problem that the liquid enters the condenser and causes liquid seal can also be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of refrigeration technology, and particularly relates to a refrigeration system with automatic liquid return. BACKGROUND

[0002] With the large application of 4G and the gradual popularization of 5G, the heat generation of various data processing equipment is getting larger and larger, and the data center has higher and higher requirements for the refrigerating capacity and energy saving of air conditioning equipment.

[0003] Using the outdoor natural cold source in the transition season and cold winter to cool the data center can greatly reduce the operating cost of the air conditioning equipment. Commonly, a fluorine pump air conditioner is used, the fluorine pump mode is started in winter, the operation of the compressor is stopped, and the fluorine pump is used to drive the refrigerant to realize heat pipe refrigeration operation, thereby greatly reducing the operating cost of the equipment.

[0004] The fluorine pump compression refrigeration system belongs to a composite system, and the fluorine pump heat pipe system and the compression refrigeration system share an evaporator and a condenser, as well as some shared refrigerant pipelines, system components and the like.

[0005] In the fluorine pump refrigeration mode of the above composite system, the refrigerant gas at the outlet of the evaporator can carry a large amount of un-evaporated refrigerant liquid. The refrigerant liquid is prone to accumulate on the gas pipeline before entering the condenser, thereby causing a liquid blocking problem, so as to block the flow of the refrigerant gas in some channels, and thus affect the gas distribution uniformity and heat exchange efficiency of the condenser. The liquid blocking also affects the flow resistance of the fluorine pump heat pipe circulation, and is prone to destroy the stable operation of the fluorine pump. Therefore, it is necessary to intercept the refrigerant liquid at the outlet of the evaporator and prevent it from returning to the condenser. The more refrigerant liquid is intercepted, the less refrigerant liquid is left in the storage tank, which threatens the operation reliability of the fluorine pump. Therefore, the intercepted refrigerant liquid must be returned to the storage tank as soon as possible.

[0006] In compression refrigeration mode, to prevent liquid refrigerant from entering the compressor or condenser, the return main is usually connected above the highest possible liquid level in the evaporator's main gas collector. However, this easily leads to liquid refrigerant and lubricating oil accumulating at the bottom of the main gas collector because the refrigerant flow rate and velocity in the bottom branch are low, unable to carry enough liquid refrigerant and / or lubricating oil upwards. Over time, this causes liquid refrigerant and some lubricating oil to accumulate at the bottom of the main gas collector. As the liquid level gradually rises, a liquid seal can easily form in the bottom branch, further reducing the refrigerant flow and causing a "liquid storage" phenomenon at the bottom of the evaporator. Obviously, this liquid refrigerant will also contain more lubricating oil, easily causing insufficient refrigerant circulation and insufficient oil return in the refrigeration system. In refrigerant pump refrigeration mode, the more liquid refrigerant accumulates at the bottom of the evaporator, the less liquid refrigerant remains in the receiver tank, resulting in a lower liquid level and increasing the risk of refrigerant pump cavitation.

[0007] Therefore, it is necessary to address the issue of liquid accumulation in the lower part of the evaporator and / or the lower part of the evaporator's main gas collection pipe to avoid insufficient refrigerant participating in the system's circulation and affecting the evaporator's heat exchange performance.

[0008] Because existing fluorine pump refrigeration systems suffer from liquid accumulation in the lower part of the evaporator and / or the lower part of the evaporator's main gas collection pipe, resulting in insufficient refrigerant charge participating in the system's circulation and affecting the evaporator's heat exchange performance, this invention researches and designs an automatic liquid return refrigeration system. Summary of the Invention

[0009] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the prior art in the fluorine pump compression refrigeration system, which has the problem of liquid accumulation in the lower part of the evaporator and / or the lower part of the evaporator's gas collection manifold, resulting in insufficient refrigerant participating in the circulation in the system and affecting the heat exchange performance of the evaporator, thereby providing an automatic liquid return refrigeration system.

[0010] To address the above problems, the present invention provides an automatic liquid return refrigeration system, comprising:

[0011] The system includes an evaporator, a gas-liquid separator, and an oil separator. The interior of the gas-liquid separator is connected to the interior of the evaporator via a return pipe, which allows liquid from the evaporator to be discharged into the gas-liquid separator.

[0012] It also includes a return gas pipe, one end of which is connected to the interior of the gas-liquid separator and the other end of which is connected to the interior of the oil separator, so that the gas separated inside the gas-liquid separator can be introduced into the oil separator through the return gas pipe, and the liquid at the bottom of the oil separator can be returned to the gas-liquid separator through the return gas pipe.

[0013] In some implementations...

[0014] A one-way valve B is installed on the return gas pipe. The one-way valve B is configured to allow airflow only from the inside of the gas-liquid separator to the oil separator, while also allowing the liquid inside the oil separator to flow back into the gas-liquid separator. The bottom of the oil separator is higher than the top of the gas-liquid separator, so that the liquid at the bottom of the oil separator can automatically return to the gas-liquid separator by gravity through the return gas pipe.

[0015] In some implementations...

[0016] The oil separator has an oil level of a first preset height inside. The return gas pipe is inserted into the oil separator from the bottom, and the height of the return gas pipe inserted into the oil separator does not exceed the height of the oil in the oil separator.

[0017] In some implementations...

[0018] It also includes a blocking structure and a float.

[0019] The blocking structure is disposed in the gas-liquid separator, and the blocking structure divides the internal cavity of the gas-liquid separator into an upper cavity and a lower cavity. The upper cavity forms a separation chamber, and the lower cavity forms a liquid storage chamber. The blocking structure is provided with a through hole running vertically through it and / or a through hole is formed between the blocking structure and the inner wall of the gas-liquid separator, and the through hole connects the separation chamber and the liquid storage chamber.

[0020] The bottom of the gas-liquid separator is also provided with a liquid outlet, and a float is provided at the liquid outlet. At least a part of the structure of the float is located in the liquid storage chamber and at least a part of the structure is located in the liquid outlet. The float can rise as the liquid level in the liquid storage chamber rises. When the liquid level in the liquid storage chamber is greater than or equal to a second preset height, the float is floated by the liquid and opens the liquid outlet. When the liquid level in the liquid storage chamber is less than the second preset height, the float falls down under its own weight and closes the liquid outlet.

[0021] In some implementations...

[0022] The blocking structure is a baffle plate structure, which can block at least part of the airflow in the separation chamber from entering the liquid storage chamber. The gas-liquid separator is a cylindrical structure with a central axis. The connecting hole is located near the inner wall of the gas-liquid separator relative to the central axis. There are multiple connecting holes, and the multiple connecting holes are arranged at intervals in the circumferential direction of the baffle plate.

[0023] In some implementations...

[0024] It also includes an air inlet pipe, and the evaporator also includes a gas collecting pipe, which is located at the outlet end of the evaporator. One end of the air inlet pipe is connected to the separation chamber and the other end is connected to the gas collecting pipe, so as to introduce the gas generated by the evaporator into the separation chamber. One end of the liquid return pipe is connected to the liquid storage chamber and the other end is connected to the bottom of the gas collecting pipe. One end of the gas return pipe is connected to the separation chamber.

[0025] In some implementations...

[0026] It also includes a compressor and an outlet pipe. One end of the outlet pipe is connected to the separation chamber of the gas-liquid separator, and the other end is connected to the suction port of the compressor, so that the gas separated inside the gas-liquid separator can be introduced into the compressor through the outlet pipe.

[0027] In some implementations...

[0028] It also includes a condenser, a first pipeline, a second pipeline, and a third pipeline. One end of the first pipeline is connected to the outlet of the compressor, and the other end is connected to the inner top of the oil separator. One end of the second pipeline is connected to the inner top of the oil separator, and the other end is connected to one end of the condenser. One end of the third pipeline is connected to the outlet pipe, and the other end is connected to the return pipe. A throttling device is provided on the third pipeline.

[0029] In some implementations...

[0030] The top plate of the gas-liquid separator is provided with an air inlet, an air return outlet, and an air outlet. One end of the air inlet pipe is inserted into the separation chamber of the gas-liquid separator through the air inlet, and the other end is connected to the interior of the gas collecting pipe. The air return pipe is inserted into the separation chamber of the gas-liquid separator through the air return outlet, and the air outlet pipe is inserted into the separation chamber of the gas-liquid separator through the air outlet.

[0031] In some implementations...

[0032] The outlet pipe has a U-shaped structure, with one end of the U-shaped pipe located in the separation chamber to draw fluid from the separation chamber, and the other end of the U-shaped pipe extending from the top of the gas-liquid separator to communicate with the suction port of the compressor. The bottom part of the U-shaped bend of the outlet pipe is located in the liquid storage chamber, and an oil return port is provided on the bottom part of the U-shaped bend. The oil return port penetrates the inner and outer walls of the bottom part of the U-shaped bend so that liquid in the liquid storage chamber can be drawn into the outlet pipe through the oil return port.

[0033] In some implementations...

[0034] The lower end of the return pipe is vertically opposite to the inlet end of the outlet pipe of the U-shaped pipe structure, and the two are separated by a preset distance greater than 0. The return pipe is a straight pipe, and its central axis coincides with the central axis of the inlet end of the outlet pipe and the central axis of the gas-liquid separator.

[0035] In some implementations...

[0036] It also includes a fluorine pump, and the lower end of the outlet is connected to an outlet pipe. One end of the outlet pipe is connected to the storage chamber through the outlet, and the other end is connected to the inlet of the fluorine pump.

[0037] The bottom of the gas-liquid separator is also provided with a liquid return port. One end of the liquid return pipe is inserted into the liquid storage chamber of the gas-liquid separator through the liquid return port, and the other end is connected to the bottom of the gas collecting pipe.

[0038] In some implementations...

[0039] The liquid outlet pipe is also equipped with a one-way valve C, which only allows fluid to flow from the gas-liquid separator to the fluorine pump.

[0040] In some implementations...

[0041] It also includes a storage tank, a one-way valve A, an expansion valve, a fourth pipeline, a fifth pipeline, and a sixth pipeline. The inlet end of the fluorine pump is connected to the bottom of the storage tank via the fourth pipeline, and the outlet end of the fluorine pump is connected to the evaporator via the fifth pipeline. The expansion valve is also installed on the fifth pipeline. One end of the sixth pipeline is connected to the position between the storage tank and the fluorine pump on the fourth pipeline, and the other end of the sixth pipeline is connected to the position between the fluorine pump and the expansion valve on the fifth pipeline. The outlet end of the condenser is connected to the inner top of the storage tank via the seventh pipeline.

[0042] The automatic liquid return refrigeration system provided by this invention has the following beneficial effects:

[0043] 1. This invention, by setting up a gas-liquid separator and a return liquid pipe, connects the return liquid pipe to the inner bottom of the evaporator or the inner bottom of the evaporator's gas collecting pipe, and the interior of the gas-liquid separator. The return liquid pipe directly connects the liquid storage chamber at the bottom of the gas-liquid separator and the bottom port of the gas collecting pipe, allowing the liquid at the bottom of the gas collecting pipe to flow directly to the bottom of the gas-liquid separator. This effectively guides the refrigerant liquid accumulated at the bottom of the evaporator or the bottom of the evaporator's gas collecting pipe out, allowing it to enter the gas-liquid separator and then circulate within the refrigeration system. Simultaneously, by connecting the gas-liquid separator to the oil separator via a return gas pipe that connects to the interior of the oil separator, the gas separated in the gas-liquid separator can be introduced into the oil separator. The separator also guides the liquid from the bottom of the oil separator after gas-liquid separation back to the gas-liquid separator through the return gas pipe, achieving secondary gas-liquid separation. This ensures that the refrigerant gas no longer carries refrigerant liquid into the condenser, avoiding liquid blockage or liquid seal on the gas pipeline. The refrigerant liquid separated a second time in the oil separator flows back to the gas-liquid separator along the pipe wall under gravity, forming a countercurrent with the rising gas in the pipe. This effectively solves the problem of liquid accumulation in the lower part of the evaporator and / or the lower part of the evaporator's main gas collection pipe, which leads to insufficient refrigerant charge participating in the system cycle and affects the heat exchange performance of the evaporator. It also solves the problem of liquid entering the condenser and causing liquid seal.

[0044] 2. This invention also utilizes a blocking structure inside the gas-liquid separator, which interacts with the lower float plug to divide the interior of the gas-liquid separator into an upper separation chamber and a lower storage chamber. This allows the gas-liquid mixture entering the separation chamber through the inlet pipe to undergo effective gas-liquid separation. The separated liquid enters the lower storage chamber through a connecting hole and can be further discharged through the float plug at the outlet. The gas is then discharged from the gas-liquid separator through a return gas pipe (fluorine pump mode) or an outlet gas pipe (compression mode). The blocking structure effectively reduces the intensity of the upper airflow disturbing the liquid surface, ensuring the normal operation of the float plug on the liquid surface and guaranteeing the normal liquid flow and gas blocking functions.

[0045] 3. The present invention also incorporates a U-shaped tube structure for the outlet pipe, with an oil return port at the bottom of the bend in the outlet pipe. This allows liquid from the storage chamber to be drawn into the U-shaped tube and into the compressor during compression operation, thus contributing to the refrigeration cycle. This further prevents insufficient refrigerant and oil levels during the cycle. During refrigerant pump refrigeration, the liquid level in the storage chamber gradually increases, causing the float to rise. Through the outlet and outlet pipe, the liquid inside the storage chamber flows back to the refrigerant pump's suction port via the one-way valve C, ensuring sufficient refrigerant circulation in the refrigeration system.

[0046] 4. The present invention further improves the efficiency of gas separation by positioning the lower end of the return pipe and the inlet end of the outlet pipe of the U-shaped pipe structure vertically opposite each other, with a predetermined distance between them greater than 0. The return pipe is a straight pipe, and its central axis coincides with the central axis of the inlet end of the outlet pipe and the central axis of the gas-liquid separator. This allows high-speed gas to enter the gas-liquid separator from the inlet pipe, rotate and flow downwards, and bounce back and flow upwards along the central axis of the cylinder after contacting the baffle. Therefore, the inlet ends of the return pipe and the U-shaped outlet pipe are set on the central axis, which conforms to the gas flow trend. This allows more gas-liquid mixture to contact the baffle and the inner wall to complete gas-liquid separation. Attached Figure Description

[0047] Figure 1 This is a system schematic diagram of the automatic liquid return refrigeration system of the present invention;

[0048] Figure 2 This is a front sectional view of the gas-liquid separator of the automatic liquid return refrigeration system of the present invention;

[0049] Figure 3 yes Figure 2 Top view of the gas-liquid separator in the diagram;

[0050] Figure 4 yes Figure 2 A top view of the blocking structure in the diagram.

[0051] The reference numerals in the attached figures are as follows:

[0052] 1. Evaporator; 2. Gas-liquid separator; 3. Oil separator; 4. Liquid return pipe; 5. Gas return pipe; 6. Baffle structure; 7. Inlet pipe; 8. Separation chamber; 9. Liquid storage chamber; 10. Connecting hole; 11. Compressor; 12. Gas outlet pipe; 13. Gas inlet; 14. Gas return port; 15. Gas outlet; 16. Gas collection pipe; 17. Oil return port; 18. One-way valve B; 19. Throttling device; 20. Refrigerant pump; 21. Liquid outlet; 22. Liquid return port; 23. Liquid outlet pipe; 24. Float; 25. One-way valve C; 26. Liquid storage tank; 27. One-way valve A; 28. Expansion valve; 29. ​​Condenser; 30. Internal fan; 31. External fan;

[0053] 101. First pipeline; 102. Second pipeline; 103. Third pipeline; 104. Fourth pipeline; 105. Fifth pipeline; 106. Sixth pipeline; 107. Seventh pipeline. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0056] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0057] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0058] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0059] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0060] like Figures 1-4 As shown, the present invention provides an automatic liquid return refrigeration system (preferably a refrigerant pump compression dual-cycle system), comprising:

[0061] Evaporator 1, gas-liquid separator 2 and oil separator 3, wherein the interior of gas-liquid separator 2 is connected to the interior of evaporator 1 through liquid return pipe 4, so that liquid inside evaporator 1 can be discharged to gas-liquid separator 2;

[0062] It also includes a return pipe 5, one end of which is connected to the interior of the gas-liquid separator 2 and the other end is connected to the interior of the oil separator 3, so that the gas separated inside the gas-liquid separator 2 can be introduced into the oil separator 3 through the return pipe 5, and the liquid inside the oil separator 3 can be returned to the gas-liquid separator 2 through the return pipe 5.

[0063] This invention, by incorporating a gas-liquid separator and a return liquid pipe, connects the return liquid pipe to the inner bottom of the evaporator or the inner bottom of the evaporator's gas collecting pipe, and to the interior of the gas-liquid separator. The return liquid pipe directly connects the liquid storage chamber at the bottom of the gas-liquid separator to the bottom port of the gas collecting pipe, allowing the liquid at the bottom of the gas collecting pipe to flow directly to the bottom of the gas-liquid separator. This effectively guides the refrigerant liquid accumulated at the bottom of the evaporator or the bottom of the evaporator's gas collecting pipe out, allowing it to enter the gas-liquid separator and then circulate within the refrigeration system. Furthermore, by connecting the gas-liquid separator to the oil separator via a return gas pipe that connects to the interior of the oil separator, the gas separated in the gas-liquid separator can be introduced into the oil separator. The oil separator also guides the liquid from the bottom of the oil separator after gas-liquid separation back to the gas-liquid separator through the return gas pipe, achieving secondary gas-liquid separation. This ensures that the refrigerant gas no longer carries refrigerant liquid into the condenser, avoiding liquid blockage or liquid seal on the gas pipeline. The refrigerant liquid separated in the second stage in the oil separator flows back to the gas-liquid separator along the pipe wall under gravity, forming a countercurrent with the rising gas in the pipe. This effectively solves the problem of liquid accumulation in the lower part of the evaporator and / or the lower part of the evaporator's main gas collection pipe, which leads to insufficient refrigerant charge participating in the system cycle and affects the heat exchange performance of the evaporator. It also solves the problem of liquid entering the condenser and causing liquid seal.

[0064] In some implementations...

[0065] A one-way valve B18 is provided on the return air pipe 5. The one-way valve B18 is configured to allow airflow only from the inside of the gas-liquid separator 2 to the oil separator 3, while also allowing the liquid inside the oil separator 3 to flow back into the gas-liquid separator 2. The bottom of the oil separator is higher than the top of the gas-liquid separator, so that the liquid at the bottom of the oil separator 3 can automatically return to the gas-liquid separator 2 by gravity through the return air pipe 5.

[0066] This invention also utilizes the structural design of the one-way valve B to prevent gas from flowing from the gas-liquid separator to the oil separator (in fluorine pump mode), while allowing gas flow from the gas-liquid separator to the oil separator. It also prevents gas from flowing back into the gas-liquid separator, especially in compression mode, through the oil separator and return pipe. In fluorine pump mode, when the gas separated from the gas-liquid separator passes through the one-way valve B, the valve opens. At this time, the liquid at the bottom of the oil separator flows back along the pipe wall due to gravity to the open one-way valve B, and then further flows back into the gas-liquid separator, forming a secondary separation effect. This further improves the gas-liquid separation effect, ensuring that the gas entering the condenser is of higher purity, preventing liquid from entering the condenser and causing a liquid seal, and avoiding a reduction in the condenser's heat exchange performance. Through the height arrangement of the oil separator and the gas-liquid separator, the liquid at the bottom of the oil separator can automatically return to the gas-liquid separator, achieving an automatic liquid return effect.

[0067] This invention utilizes a return pipe to directly connect the liquid storage chamber at the bottom of the gas-liquid separator and the bottom port of the gas collecting pipe, allowing the liquid at the bottom of the gas collecting pipe to flow directly to the bottom of the gas-liquid separator. The multi-functional gas-liquid separator has an independent return port connected to the inlet of one-way valve B. The outlet of one-way valve B is connected between the oil separator and the throttling device 19 (preferably an oil return capillary). In refrigerant pump refrigeration mode, the refrigerant at the evaporator outlet undergoes its first gas-liquid separation in the gas-liquid separator. After exiting the gas-liquid separator, it enters the oil separator through one-way valve B for a second gas-liquid separation, ensuring that the refrigerant gas no longer carries refrigerant liquid into the condenser, thus preventing liquid blockage or seals in the gas pipeline. The refrigerant liquid separated a second time in the oil separator, under gravity, flows back to the gas-liquid separator along the pipe wall, counter-currently with the rising gas in the pipe.

[0068] The present invention solves the following technical problems:

[0069] 1. Problem of liquid accumulation in the lower part of the evaporator and / or the lower part of the evaporator's main gas collection pipe;

[0070] 2. Liquid enters the condenser inlet, causing liquid blockage and liquid seal in the gas pipeline.

[0071] In some implementations...

[0072] The oil separator 3 contains oil at a first preset height. The return air pipe 5 is inserted into the oil separator 3 from the bottom, and the height of the return air pipe 5 inserted into the oil separator 3 does not exceed the height of the oil in the oil separator 3.

[0073] This is a further preferred structural form of the oil separator and return gas pipe of the present invention, namely, the height of the return gas pipe inserted into the oil separator is preferably no more than the height of the oil, so as to ensure that the liquid at the bottom of the oil separator is discharged and improve the efficiency of liquid or oil return.

[0074] In some implementations...

[0075] It also includes the blocking structure 6 and the float 24.

[0076] The blocking structure 6 is disposed in the gas-liquid separator 2, and the blocking structure 6 divides the internal cavity of the gas-liquid separator 2 into an upper cavity and a lower cavity. The upper cavity forms a separation chamber 8, and the lower cavity forms a liquid storage chamber 9. The blocking structure 6 is provided with a through hole 10 and / or the blocking structure 6 and the inner wall of the gas-liquid separator 2 form a through hole 10, and the through hole 10 connects the separation chamber 8 and the liquid storage chamber 9.

[0077] The bottom of the gas-liquid separator 2 is also provided with a liquid outlet 21, and a float 24 is provided at the liquid outlet 21. At least a part of the structure of the float 24 is located in the liquid storage chamber 9, and at least a part of the structure is located in the liquid outlet 21 and the liquid outlet pipe 23. The float 24 can rise as the liquid level in the liquid storage chamber 9 rises. When the liquid level in the liquid storage chamber 9 is greater than or equal to a second preset height, the float 24 is floated by the liquid and opens the liquid outlet 21. When the liquid level in the liquid storage chamber 9 is less than the second preset height, the float 24 falls down under its own weight and closes the liquid outlet 21.

[0078] This invention also utilizes a blocking structure inside the gas-liquid separator, which interacts with the float below to divide the separator into an upper separation chamber and a lower storage chamber. This allows the gas-liquid mixture entering the separation chamber through the inlet pipe to undergo effective gas-liquid separation. The separated liquid enters the lower storage chamber through a connecting hole and can be discharged through the outlet. The gas is then exited from the gas-liquid separator through a return pipe (fluorine pump mode) or an outlet pipe (compression mode). The blocking structure effectively reduces the intensity of the upper airflow disturbing the liquid surface, ensuring the normal operation of the float on the liquid surface and guaranteeing the normal function of liquid flow and gas blocking.

[0079] This invention designs a multifunctional gas-liquid separator, which adopts an upper gas-liquid separation chamber and a lower liquid storage chamber connected to each other, reducing the intensity of airflow disturbance on the liquid surface and ensuring the normal operation of the float plug on the liquid surface; the return pipe directly connects the liquid storage chamber at the bottom of the gas-liquid separator and the bottom port of the gas collecting pipe, so that the liquid at the bottom of the gas collecting pipe can flow directly to the bottom of the gas-liquid separator.

[0080] This effectively solves the problem of liquid accumulation at the bottom of the gas collecting pipe, allowing the accumulated liquid to quickly and efficiently return to the bottom liquid storage chamber of the gas-liquid separator. In compression refrigeration mode, the liquid is then drawn back to the compressor via the oil return orifice of the gas-liquid separator, carried by the high-speed airflow, thus ensuring the system's circulation volume. In refrigerant pump refrigeration mode, the liquid in the storage chamber gradually increases, causing the float plug to rise. The liquid then flows back to the refrigerant pump's suction port through the one-way valve C, ensuring the system's circulation volume. This multi-functional gas-liquid separator can achieve gas-liquid separation, and the separated and stored liquid in various operating modes can continue to effectively participate in the system's circulation without accumulating inside the gas-liquid separator.

[0081] In this invention, the return pipe and the outlet pipe are preferably located in the liquid storage chamber with their openings slightly higher than the inner bottom surface of the cylinder. A low-density float plug is also provided on the inner opening of the outlet pipe. The density of the float plug is less than the density of the refrigerant liquid and / or the density of the lubricating oil and / or the mixed density of the oil-containing refrigerant liquid. The float plug preferably has a circular floating plate in the middle and slender cylindrical structures at the upper and lower ends. The lower cylinder is inserted into the outlet pipe and can float freely up and down (the diameter of the lower cylinder is smaller than the inner diameter of the outlet pipe). When the top of the upper cylinder abuts against the lower end face of the baffle plate, more than 1 / 2 of the lower cylinder is still inserted into the outlet pipe, thereby ensuring that the float plug will not fall out of the outlet pipe.

[0082] In some implementations...

[0083] The blocking structure 6 is a baffle plate structure that can block at least part of the airflow in the separation chamber 8 from entering the liquid storage chamber 9. The gas-liquid separator 2 is a cylindrical structure with a central axis. The connecting hole 10 is located closer to the inner wall of the gas-liquid separator 2 than the central axis. There are multiple connecting holes 10, and the multiple connecting holes 10 are arranged at intervals in the circumferential direction of the baffle plate.

[0084] This is a preferred structural form of the blocking structure of the present invention, namely, a baffle structure that separates the separation chamber and the liquid storage chamber to a certain extent, so that the liquid separated in the separation chamber can flow into the liquid storage chamber below through the connecting hole; the connecting hole is preferably located near the inner wall of the gas-liquid separator, so that most of the discharged liquid can be discharged, further improving the efficiency of gas-liquid separation; the connecting hole of the present invention is preferably multiple and arranged at intervals along the circumferential direction, which can increase the flow area, increase the downstream flow velocity and flow rate of the liquid, and further improve the efficiency of gas-liquid separation.

[0085] like Figure 2As shown, this invention provides a multifunctional gas-liquid separator with a baffle plate, which consists of a cylindrical sealed cylinder, an air inlet pipe, an air return pipe, a U-shaped air outlet pipe, a baffle plate, a liquid return pipe, and a liquid outlet pipe. All pipes are welded and sealed at the points where they pass through the cylinder, and the inner and outer sides of the cylinder are connected through the inner and outer pipe openings. The gas-liquid separator is divided into a separation chamber and a liquid storage chamber by a horizontal baffle plate. The baffle plate can reduce the impact of the violent high-speed rotating airflow at the top on the liquid surface at the bottom, thereby ensuring the stability of the liquid surface as much as possible, which also ensures the stability of the float plug on the liquid surface.

[0086] In this invention, a small gap (forming a connecting hole 10) is preferably reserved between the baffle plate and the inner wall of the cylinder. The preferred gap value is equivalent to the pore size of the filter screen installed on the oil return port, so that larger solid particles in the upper separation chamber cannot enter the lower liquid outlet chamber through this gap, thereby reducing solid impurities in the liquid at the bottom. The liquid separated in the upper separation chamber flows downward along the inner wall of the cylinder and flows into the liquid storage chamber at the bottom after passing through the small gap between the baffle plate.

[0087] Alternatively, the baffle plate can be fixed to the inner wall of the cylinder by interference fit, welding, or other limiting structures. In this case, there is no gap between the baffle plate and the inside of the cylinder. The outer periphery of the baffle plate is provided with several tiny connecting holes 10 to connect the upper and lower separation chambers and the liquid storage chamber, so that the liquid separated in the upper separation chamber can enter the lower liquid storage chamber through these connecting holes.

[0088] In some implementations...

[0089] It also includes an air inlet pipe 7, and the evaporator 1 also includes a gas collecting pipe 16, which is located at the outlet end of the evaporator 1. One end of the air inlet pipe 7 is connected to the separation chamber 8 and the other end is connected to the gas collecting pipe 16, so as to introduce the gas generated by the evaporator 1 into the separation chamber 8. One end of the liquid return pipe 4 is connected to the liquid storage chamber 9 and the other end is connected to the bottom of the gas collecting pipe 16. One end of the gas return pipe 5 is connected to the separation chamber 8.

[0090] This invention uses a gas collecting pipe to collect the gas at the evaporator outlet for exhaust. An inlet pipe connects the upper end of the gas collecting pipe to the separation chamber, allowing the gas (a gas-liquid mixture with a higher gas content) in the upper part of the collecting pipe to be discharged into the gas-liquid separator for separation. A return pipe connects the bottom of the collecting pipe to the liquid storage chamber, allowing the liquid accumulated at the bottom of the collecting pipe to be discharged into the liquid storage chamber, reducing excessive liquid accumulation at the bottom of the collecting pipe and increasing the cooling capacity of the system cycle. The return pipe is connected to the separation chamber, allowing the separated gas to be discharged into the oil separator, satisfying the refrigerant circulation supply in refrigerant pump mode.

[0091] The air inlet pipe of this invention is located inside the cylinder and has a vertical bend that connects to a horizontal pipe section. This causes the vertically downward high-speed gas to change its flow direction to horizontal and flow horizontally along the tangential direction of the cylinder wall. After impacting the inner wall of the cylinder, it forms a high-speed rotating airflow. The rotating airflow rotates and moves downward along the wall. Under the action of centrifugal force, the liquid carried by the high-speed gas is thrown onto the wall and flows downward along the wall to accumulate at the bottom of the cylinder. The high-speed rotating downward gas flows downward and impacts the wind baffle and / or the bottom surface of the cylinder and / or the liquid surface at the bottom. After rebounding, it flows upward along the central axis of the cylinder and then flows out of the cylinder from the U-shaped air outlet pipe or air return pipe, thereby completing the gas-liquid separation function.

[0092] In some implementations...

[0093] It also includes a compressor 11 and an outlet pipe 12. One end of the outlet pipe 12 is connected to the separation chamber 8 of the gas-liquid separator 2, and the other end is connected to the air intake of the compressor 11, so that the gas separated inside the gas-liquid separator 2 can be introduced into the compressor 11 through the outlet pipe 12.

[0094] The present invention also incorporates a compressor, with an outlet pipe connecting the separation chamber and the compressor's intake port, which allows the gas separated by the gas-liquid separator to be guided to the compressor for compression, thereby ensuring the refrigerant circulation in the refrigeration cycle system under compression mode.

[0095] In some implementations...

[0096] It also includes a condenser 29, a first pipe 101, a second pipe 102 and a third pipe 103. One end of the first pipe 101 is connected to the outlet of the compressor 11 and the other end is connected to the inner top of the oil separator 3. One end of the second pipe 102 is connected to the inner top of the oil separator 3 and the other end is connected to one end of the condenser 29. One end of the third pipe 103 is connected to the outlet pipe 12 and the other end is connected to the return pipe 5. A throttling device 19 is provided on the third pipe 103.

[0097] This invention also establishes a connection between the compressor, oil separator, and condenser through the arrangement of the condenser and the first to third pipelines. This ensures that the gas at the compressor outlet first passes through the oil separator to separate the oil before entering the condenser. The third pipeline allows the oil to flow back into the compressor, ensuring the compressor's normal lubrication requirements. Furthermore, the oil separator, through the return gas pipe, can guide the liquid inside the oil separator back to the gas-liquid separator in refrigerant pump mode, achieving secondary gas-liquid separation, improving the gas-liquid separation effect, and further ensuring that the refrigerant entering the condenser is in a gaseous state, avoiding liquid sealing.

[0098] In some implementations...

[0099] The top plate of the gas-liquid separator 2 is provided with an air inlet 13, an air return port 14, and an air outlet 15. One end of the air inlet pipe 7 is inserted into the separation chamber 8 of the gas-liquid separator 2 through the air inlet 13, and the other end is connected to the interior of the gas collecting pipe 16. The air return pipe 5 is inserted into the separation chamber 8 of the gas-liquid separator 2 through the air return port 14, and the air outlet pipe 12 is inserted into the separation chamber 8 of the gas-liquid separator 2 through the air outlet 15.

[0100] This is a further preferred structural form of the gas-liquid separator of the present invention, namely, through the air inlet, air return and air outlet provided on its top, it can be inserted into the air inlet pipe, air return pipe and air outlet pipe respectively, so as to ensure that the multiple pipes realize the connection between the separation chamber inside the gas-liquid separator and the gas collecting pipe, oil separator and compressor respectively.

[0101] In some implementations...

[0102] The outlet pipe 12 has a U-shaped structure. One end of the U-shaped pipe is located in the separation chamber 8 to draw fluid from the separation chamber 8. The other end of the U-shaped pipe extends from the top of the gas-liquid separator 2 and can communicate with the suction port of the compressor 11. The bottom part of the U-shaped bend of the outlet pipe 12 is located in the liquid storage chamber 9. An oil return port 17 is provided on the bottom part of the U-shaped bend. The oil return port 17 penetrates the inner and outer walls of the bottom part of the U-shaped bend so that the liquid in the liquid storage chamber 9 can be drawn into the outlet pipe 12 through the oil return port 17.

[0103] This is a preferred structure of the outlet pipe of the present invention. An oil return port is provided at the bottom of the bend section of the outlet pipe. In the compression operation mode, the liquid in the liquid storage chamber can be drawn into the U-shaped pipe through the oil return port and enter the compressor, thereby adding it to the refrigeration cycle system. This further avoids the situation where the amount of refrigerant and oil participating in the cycle is too small. In the refrigerant pump refrigeration mode, the liquid in the liquid storage chamber gradually increases, thereby raising the float plug. Through the liquid outlet and the liquid outlet pipe, the liquid in the liquid storage chamber flows back to the liquid suction port of the refrigerant pump from the one-way valve C, thereby ensuring the amount of refrigerant circulating in the refrigeration system.

[0104] The U-shaped exhaust pipe of the present invention has a bent section at the bottom near the bottom of the cylinder, and an oil return port is provided on the side, preferably with a filter screen on the oil return port.

[0105] The wind deflector of the present invention is preferably sleeved on the U-shaped air outlet pipe, that is, the wind deflector is provided with at least two connecting holes, and the two ends of the U-shaped air outlet pipe can pass through the two connecting holes respectively, so that the wind deflector is locked on the bent section at the bottom of the U-shaped air outlet pipe.

[0106] In some implementations...

[0107] The lower end of the return pipe 5 is vertically opposite to the air inlet end of the outlet pipe 12 of the U-shaped pipe structure, and the two are separated by a preset distance greater than 0. The return pipe 5 is a straight pipe, and its central axis coincides with the central axis of the air inlet end of the outlet pipe 12 and the central axis of the gas-liquid separator 2.

[0108] The present invention further improves the efficiency of gas separation by positioning the lower end of the return pipe and the inlet end of the outlet pipe of the U-shaped pipe structure vertically opposite each other, with a predetermined distance between them greater than zero. The return pipe is a straight pipe, and its central axis coincides with the central axis of the inlet end of the outlet pipe and the central axis of the gas-liquid separator. This allows high-speed gas to enter the gas-liquid separator from the inlet pipe, rotate and flow downwards, and bounce back and flow upwards along the central axis of the cylinder after contacting the baffle. Therefore, the inlet ends of the return pipe and the U-shaped outlet pipe are set on the central axis, which conforms to the gas flow trend. This allows more gas-liquid mixture to contact the baffle and the inner wall to complete gas-liquid separation.

[0109] In this invention, the U-shaped exhaust pipe is preferably located at the inlet end inside the cylinder, and the return pipe is located on the vertical central axis of the cylinder. The inlet ends of the two are vertically opposite but not connected. The reason for being located on the central axis is that high-speed gas enters the gas-liquid separator from the inlet pipe, rotates and flows downward, and rebounds and flows upward along the central axis of the cylinder after contacting the baffle plate. Therefore, setting the inlet ends of the return pipe and the U-shaped exhaust pipe on the central axis conforms to the gas flow trend.

[0110] In some implementations...

[0111] It also includes a fluorine pump 20, and the lower end of the outlet 21 is connected to an outlet pipe 23. One end of the outlet pipe 23 is connected to the storage chamber 9 through the outlet 21, and the other end is connected to the inlet end of the fluorine pump 20.

[0112] The bottom of the gas-liquid separator 2 is also provided with a liquid return port 22. One end of the liquid return pipe 4 is inserted into the liquid storage chamber 9 of the gas-liquid separator 2 through the liquid return port 22, and the other end is connected to the bottom of the gas collecting pipe 16.

[0113] This is a further preferred structural form of the present invention. With the setting of the fluorine pump and the liquid outlet pipe, the liquid in the liquid storage chamber gradually increases in the fluorine pump refrigeration mode, thereby raising the float plug. Through the liquid outlet and the liquid outlet pipe, the liquid inside the liquid storage chamber flows back to the liquid inlet of the fluorine pump, thereby ensuring the refrigerant circulation volume of the refrigeration system. The bottom of the gas-liquid separator is also provided with a liquid return port, which allows the liquid return pipe to be inserted, ensuring the connection between the bottom of the gas collecting pipe and the liquid storage chamber, and ensuring the effect of discharging the liquid collected at the bottom of the gas collecting pipe.

[0114] In some implementations...

[0115] The liquid outlet pipe 23 is also equipped with a one-way valve C25, which only allows fluid to flow from the gas-liquid separator 2 to the fluorine pump 20.

[0116] The present invention also ensures that the liquid separated in the liquid storage chamber of the gas-liquid separator can flow back to the refrigerant pump by setting a one-way valve C, thus ensuring the refrigerant supply to the circulation system in the refrigerant pump mode. At the same time, it prevents the refrigerant between the inlet of the refrigerant pump and the liquid storage tank from flowing back into the gas-liquid separator through the liquid outlet pipe, thereby preventing the evaporator from short-circuiting (this situation usually occurs in the compression mode).

[0117] In the present invention, the liquid in the storage chamber is drawn back to the compressor along with the high-speed airflow through the oil return hole of the gas-liquid separator in the compression refrigeration mode. In the refrigerant pump refrigeration mode, the liquid in the storage chamber gradually increases, thereby raising the float plug. The liquid flows back to the suction port of the refrigerant pump through the one-way valve C, thereby ensuring the circulation volume of the system.

[0118] In some implementations...

[0119] It also includes a storage tank 26, a one-way valve A27, an expansion valve 28, a fourth pipeline 104, a fifth pipeline 105, a sixth pipeline 106, and a seventh pipeline 107. The inlet end of the fluorine pump 20 is also connected to the bottom of the storage tank 26 through the fourth pipeline 104, and the outlet end of the fluorine pump 20 is also connected to the evaporator 1 through the fifth pipeline 105. The expansion valve 28 is also installed on the fifth pipeline 105. One end of the sixth pipeline 106 is connected to the position between the storage tank 26 and the fluorine pump 20 on the fourth pipeline 104, and the other end of the sixth pipeline 106 is connected to the position between the fluorine pump 20 and the expansion valve 28 on the fifth pipeline 105. The outlet end of the condenser 29 is connected to the inner top of the storage tank 26 through the seventh pipeline 107.

[0120] The present invention also enables the storage tank to store refrigerant at a high level in refrigerant pump mode by setting up a liquid storage tank, one-way valve A, expansion valve and multiple pipelines, so as to ensure that cavitation will not occur during the suction operation of the refrigerant pump, and the one-way valve A can effectively prevent the fluid at the outlet of the refrigerant pump from flowing back to the inlet of the refrigerant pump.

[0121] like Figure 1 As shown, the fluorine pump compression refrigeration system of the present invention consists of a compressor, an oil separator, a condenser, a liquid receiver, a fluorine pump, an expansion valve, an evaporator, and a gas-liquid separator connected in sequence; one-way valve A is connected in parallel to bypass the fluorine pump, and the flow direction of one-way valve A is only allowed from the inlet of the fluorine pump to the outlet of the fluorine pump; one-way valve B is connected in parallel to bypass the compressor, and the flow direction of one-way valve B is only allowed from the gas-liquid separator to the oil separator;

[0122] One-way valve B is connected between the gas return port of the gas-liquid separator and the oil return port of the oil separator; furthermore, the oil separator is located above the gas-liquid separator, and one-way valve B is connected in series on the connecting pipe between the two, ensuring that there are no protruding and / or recessed pipe sections in the pipe between the two (bends are allowed), thereby ensuring that the liquid in the oil separator can return to the gas-liquid separator below under the action of gravity along the inner wall of the pipe;

[0123] A throttling device 19 (preferably a return capillary tube) is connected between the oil return port of the oil separator and the air intake port of the compressor;

[0124] The upper part of the evaporator's gas collecting pipe is connected to the gas inlet of the gas-liquid separator;

[0125] The bottom port of the gas collecting pipe of the evaporator is connected to the return port of the gas-liquid separator through the return liquid pipe, so that the liquid accumulated at the bottom of the gas collecting pipe can flow directly to the bottom of the gas-liquid separator, thereby solving the problem of liquid accumulation in the lower part of the evaporator and / or gas collecting pipe.

[0126] The outlet at the bottom of the gas-liquid separator is connected to the suction port of the fluorine pump via a one-way valve C. The flow direction of the one-way valve C is only allowed from the gas-liquid separator to the suction port of the fluorine pump.

[0127] Figure 1 In medium-compression refrigeration mode, the refrigerant cycle is as follows: compressor → oil separator → condenser → liquid receiver → check valve A → expansion valve → evaporator → gas-liquid separator → compressor. In this mode, the outlet of check valve B is the high-temperature, high-pressure refrigerant gas and / or lubricating oil inside the oil separator. Therefore, check valve B cannot be open and is in a reverse high-pressure shut-off state. The liquid in the liquid receiver chamber at the bottom of the gas-liquid separator is drawn back to the compressor's suction port through the oil return hole of the gas-liquid separator in compression refrigeration mode, thus ensuring the system's circulation volume.

[0128] Figure 1In the refrigerant pump refrigeration mode, the refrigerant cycle is as follows: refrigerant pump → expansion valve → evaporator → gas-liquid separator → check valve B → oil separator → condenser → receiver tank → refrigerant pump. In this mode, the outlet pressure of the refrigerant pump and the outlet pressure of check valve A are relatively high, and check valve A is in a reverse high-pressure shut-off state. The liquid in the receiver tank at the bottom of the gas-liquid separator gradually increases in the refrigerant pump refrigeration mode, causing the float to rise. After the float rises, the internal port of the liquid outlet pipe opens, and the liquid in the receiver tank flows out through the liquid outlet pipe and returns to the suction port of the refrigerant pump through check valve C, thus ensuring the system's circulation volume. Because the multi-functional gas-liquid separator has an independent return port connected to the inlet of check valve B, and the outlet of check valve B is connected between the oil separator and the oil return capillary tube, in the refrigerant pump refrigeration mode, the refrigerant flow rate is significantly increased. The refrigerant at the generator outlet undergoes its first gas-liquid separation in the gas-liquid separator. After the refrigerant gas flows out of the gas-liquid separator, it enters the oil separator through one-way valve B for a second gas-liquid separation (the sudden increase in space within the oil separator causes a sharp decrease in gas flow rate, which helps to achieve gas-liquid separation). This ensures that the refrigerant gas flowing out of the oil separator no longer carries refrigerant liquid into the condenser, avoiding the formation of liquid blockage or liquid seal on the gas pipeline. The refrigerant liquid separated a second time in the oil separator flows back to the gas-liquid separator along the pipe wall under the action of gravity, forming a countercurrent with the rising gas in the pipe.

[0129] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A refrigeration system with automatic liquid return, characterized in that: include: Evaporator (1), gas-liquid separator (2) and oil separator (3), wherein the interior of the gas-liquid separator (2) is connected to the interior of the evaporator (1) through a return pipe (4) so ​​that the liquid inside the evaporator (1) can be discharged into the gas-liquid separator (2); It also includes a return pipe (5), one end of which is connected to the interior of the gas-liquid separator (2) and the other end is connected to the interior of the oil separator (3), so that the gas separated inside the gas-liquid separator (2) can be introduced into the oil separator (3) through the return pipe (5), and the liquid inside the oil separator (3) can be refluxed back into the gas-liquid separator (2) through the return pipe (5); a one-way valve B (18) is provided on the return pipe (5), and the one-way valve B (18) is configured to allow the airflow to flow only from the interior of the gas-liquid separator (2) to the oil separator (3), while also allowing the liquid inside the oil separator (3) to reflux back into the gas-liquid separator (2).

2. The automatic liquid return refrigeration system according to claim 1, characterized in that: The bottom of the oil separator (3) is higher than the top of the gas-liquid separator (2) so that the liquid at the bottom of the oil separator (3) can automatically return to the gas-liquid separator (2) by gravity through the return pipe (5).

3. The automatic liquid return refrigeration system according to claim 1, characterized in that: The oil separator (3) contains oil at a first preset height. The return air pipe (5) is inserted into the oil separator (3) from the bottom, and the height of the return air pipe (5) inserted into the oil separator (3) does not exceed the height of the oil in the oil separator (3).

4. The automatic liquid return refrigeration system according to claim 1, characterized in that: It also includes a blocking structure (6) and a float (24); The blocking structure (6) is disposed in the gas-liquid separator (2), and the blocking structure (6) divides the internal cavity of the gas-liquid separator (2) into an upper cavity and a lower cavity. The upper cavity forms a separation chamber (8), and the lower cavity forms a liquid storage chamber (9). The blocking structure (6) is provided with a through hole (10) and / or the blocking structure (6) forms a through hole (10) with the inner wall of the gas-liquid separator (2). The through hole (10) connects the separation chamber (8) and the liquid storage chamber (9). The bottom of the gas-liquid separator (2) is also provided with a liquid outlet (21), and a float (24) is provided at the liquid outlet (21). At least a part of the structure of the float (24) is located in the liquid storage chamber (9) and at least a part of the structure is located in the liquid outlet (21). The float (24) can rise as the liquid level in the liquid storage chamber (9) rises. When the liquid level in the liquid storage chamber (9) is greater than or equal to a second preset height, the float (24) is floated by the liquid and opens the liquid outlet (21). When the liquid level in the liquid storage chamber (9) is less than the second preset height, the float (24) falls down due to its gravity and closes the liquid outlet (21).

5. The automatic liquid return refrigeration system according to claim 4, characterized in that: The blocking structure (6) is a baffle plate structure that can block at least part of the airflow in the separation chamber (8) from entering the liquid storage chamber (9). The gas-liquid separator (2) is a cylindrical structure with a central axis. The connecting hole (10) is located closer to the inner wall of the gas-liquid separator (2) than the central axis. There are multiple connecting holes (10), and the multiple connecting holes (10) are arranged at intervals in the circumferential direction of the baffle plate.

6. The automatic liquid return refrigeration system according to claim 4, characterized in that: It also includes an air inlet pipe (7), and the evaporator (1) also includes a gas collecting pipe (16). The gas collecting pipe (16) is located at the outlet end of the evaporator (1). One end of the air inlet pipe (7) is connected to the separation chamber (8), and the other end is connected to the gas collecting pipe (16) so that the gas generated by the evaporator (1) can be introduced into the separation chamber (8). One end of the return liquid pipe (4) is connected to the liquid storage chamber (9), and the other end is connected to the bottom of the gas collecting pipe (16). One end of the return gas pipe (5) is connected to the separation chamber (8).

7. The automatic liquid return refrigeration system according to claim 6, characterized in that: It also includes a compressor (11) and an outlet pipe (12). One end of the outlet pipe (12) is connected to the separation chamber (8) of the gas-liquid separator (2), and the other end is connected to the suction port of the compressor (11) so that the gas separated inside the gas-liquid separator (2) can be introduced into the compressor (11) through the outlet pipe (12).

8. The automatic liquid return refrigeration system according to claim 7, characterized in that: It also includes a condenser (29), a first pipeline (101), a second pipeline (102) and a third pipeline (103). One end of the first pipeline (101) is connected to the outlet of the compressor (11) and the other end is connected to the inner top of the oil separator (3). One end of the second pipeline (102) is connected to the inner top of the oil separator (3) and the other end is connected to one end of the condenser (29). One end of the third pipeline (103) is connected to the outlet pipe (12) and the other end is connected to the return pipe (5). A throttling device (19) is provided on the third pipeline (103).

9. The automatic liquid return refrigeration system according to claim 7, characterized in that: The top plate of the gas-liquid separator (2) is provided with an air inlet (13), a return air inlet (14) and an air outlet (15). One end of the air inlet pipe (7) is inserted into the separation chamber (8) of the gas-liquid separator (2) through the air inlet (13), and the other end is connected to the interior of the gas collecting pipe (16). The return air pipe (5) is inserted into the separation chamber (8) of the gas-liquid separator (2) through the return air inlet (14), and the air outlet pipe (12) is inserted into the separation chamber (8) of the gas-liquid separator (2) through the air outlet (15).

10. The automatic liquid return refrigeration system according to claim 7, characterized in that: The outlet pipe (12) has a U-shaped pipe structure. One end of the U-shaped pipe is located in the separation chamber (8) so that fluid can be drawn from the separation chamber (8). The other end of the U-shaped pipe passes through the top of the gas-liquid separator (2) and can extend to communicate with the suction port of the compressor (11). The bottom part of the U-shaped bend of the outlet pipe (12) is located in the liquid storage chamber (9). An oil return port (17) is provided on the bottom part of the U-shaped bend. The oil return port (17) penetrates the inner and outer walls of the bottom part of the U-shaped bend so that the liquid in the liquid storage chamber (9) can be drawn into the outlet pipe (12) through the oil return port (17).

11. The automatic liquid return refrigeration system according to claim 10, characterized in that: The lower end of the return pipe (5) is vertically opposite to the air inlet end of the outlet pipe (12) of the U-shaped pipe structure, and the two are separated by a preset distance greater than 0. The return pipe (5) is a straight pipe, and its central axis coincides with the central axis of the air inlet end of the outlet pipe (12) and coincides with the central axis of the gas-liquid separator (2).

12. The automatic liquid return refrigeration system according to any one of claims 6-11, characterized in that: It also includes a fluorine pump (20), and the lower end of the outlet (21) is connected to an outlet pipe (23). One end of the outlet pipe (23) is connected to the storage chamber (9) through the outlet (21), and the other end is connected to the inlet end of the fluorine pump (20). The bottom of the gas-liquid separator (2) is also provided with a return port (22). One end of the return pipe (4) is inserted into the liquid storage chamber (9) of the gas-liquid separator (2) through the return port (22), and the other end is connected to the bottom of the gas collecting pipe (16).

13. The automatic liquid return refrigeration system according to claim 12, characterized in that: The outlet pipe (23) is also equipped with a one-way valve C (25), which only allows fluid to flow from the gas-liquid separator (2) to the fluorine pump (20).

14. The automatic liquid return refrigeration system according to claim 12, characterized in that: It also includes a storage tank (26), a one-way valve A (27), an expansion valve (28), a fourth pipeline (104), a fifth pipeline (105), a sixth pipeline (106), and a seventh pipeline (107). The inlet end of the fluorine pump (20) is also connected to the bottom end of the storage tank (26) through the fourth pipeline (104), and the outlet end of the fluorine pump (20) is also connected to the evaporator (1) through the fifth pipeline (105). The fifth pipeline (105) also has... The expansion valve (28) is provided. One end of the sixth pipeline (106) is connected to the position between the liquid storage tank (26) and the fluorine pump (20) on the fourth pipeline (104), and the other end of the sixth pipeline (106) is connected to the position between the fluorine pump (20) and the expansion valve (28) on the fifth pipeline (105). The outlet end of the condenser (29) is connected to the inner top of the liquid storage tank (26) through the seventh pipeline (107).

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