A refrigerant recovery system, a recovery method, a storage medium, and a program product

Abstract

The application discloses a kind of refrigerant recovery system, recovery method, storage medium and program product, recovery system is used to recycle residual refrigerant in steel bottle, steel bottle is used to provide refrigerant for liquid supply system on automobile production line, including steel bottle connection module, suction booster module, gas-liquid separation and liquid storage module and control unit;Steel bottle connection module is used to connect steel bottle and suction booster module;Control unit is suitable for after receiving empty bottle alarm, control suction booster module and / or impurity gas in residual refrigerant in steel bottle is pumped to gas-liquid separation and liquid storage module;Gas-liquid separation and liquid storage module are used to carry out gas-liquid separation and storage to refrigerant and / or impurity gas transported by suction booster module.The application can convert waste residual refrigerant into available resources, avoid resource waste and reduce production cost, and can avoid the explosion risk generated by refrigerant gas leakage.

Description

A refrigerant recovery system, recovery method, storage medium, and process product. Technical Field

[0001] This invention relates to the field of automotive refrigerant recovery technology, and particularly to a refrigerant recovery system and method. Background Technology

[0002] On the final assembly line of automobile manufacturing, before a vehicle rolls off the line, its air conditioning system needs to be charged with refrigerant, such as HFC (R134a) or HFO (R1234yf), to ensure the normal operation of the air conditioning system. Large steel cylinders (also known as "refrigerant supply cylinders") are typically used as storage containers for the refrigerant, which is then transported to various charging stations via pipelines.

[0003] However, when the refrigerant in the supply cylinder is reduced to approximately 5%, the medium inside the cylinder will be in a state of gas-liquid coexistence. At this point, the proportion of gaseous refrigerant is relatively high, and the pressure inside the supply cylinder is also low, making it difficult for the supply system to draw refrigerant and unable to meet the required supply rate for production.

[0004] To ensure continuous production, operators have to remove supply cylinders containing residual refrigerant and replace them with new ones. This results in resource waste and increased production costs. Furthermore, some commonly used refrigerants are highly explosive if they leak and reach a certain concentration, posing a significant safety risk. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problem that existing automotive refrigerant supply systems cannot fully utilize the residual refrigerant in the supply cylinders, resulting in resource waste and increased production costs.

[0006] To address the aforementioned technical problems, embodiments of the present invention disclose a refrigerant recovery system for recovering residual refrigerant from a steel cylinder used to supply refrigerant to a refrigerant supply system on an automotive production line. The system includes a cylinder connection module, a suction and pressurization module, a gas-liquid separation and storage module, and a control unit. The cylinder connection module connects the steel cylinder to the suction and pressurization module. Upon receiving an empty cylinder alarm, the control unit controls the suction and pressurization module to draw residual refrigerant and / or impurity gas from the steel cylinder to the gas-liquid separation and storage module. The gas-liquid separation and storage module performs gas-liquid separation and storage of the refrigerant and / or impurity gas delivered by the suction and pressurization module.

[0007] In actual production, when only a small amount of refrigerant remains inside the cylinder (e.g., about 5%), this small amount of refrigerant often exists in a gas-liquid coexistence state and cannot be extracted by the liquid supply system, resulting in resource waste. It should be noted that in this embodiment, the small amount of refrigerant in a gas-liquid coexistence state is referred to as "residual refrigerant," and the alarm caused by the small amount of refrigerant remaining inside the cylinder and its inability to be extracted is defined as "empty cylinder alarm."

[0008] By adopting the above technical solution, the recycling system of this application embodiment, through modular design, integrates a cylinder connection module, a suction and pressurization module, a gas-liquid separation and storage module, and a control unit, which can realize efficient and automated recycling of refrigerant remaining in the cylinder of the external liquid supply system.

[0009] Specifically, when the cylinder triggers an empty cylinder alarm, the control unit activates the suction and pressurization module to extract residual refrigerant and / or any impurities that may have been mixed in from the cylinder. This residual refrigerant is typically in a gas-liquid coexistence state when the cylinder is nearly empty. The suction and pressurization module then delivers this gas-liquid coexistence state of residual refrigerant (hereinafter referred to as the "mixture") to the gas-liquid separation and storage module. The gas-liquid separation and storage module is used to separate and store the input mixture. On the one hand, it automatically separates the gaseous portion from the liquid refrigerant; on the other hand, the separated gaseous components can be discharged or processed separately, while the liquid refrigerant can be effectively stored within the module or transported to downstream containers, thereby achieving the recovery of residual refrigerant.

[0010] Based on this, the recycling system of this application can effectively solve the pain points of difficulty in extraction and material waste caused by the coexistence of gas and liquid in traditional steel cylinders. By pressurizing and intelligent exhaust, the originally discarded residual refrigerant is transformed into a usable resource, thereby significantly reducing material waste and production costs while ensuring that the liquid supply of the production line is not affected.

[0011] Preferably, the cylinder connection module includes:

[0012] The first interface is used to connect to the first gas cylinder and is connected to the suction and pressurization module through a pipeline;

[0013] A second interface is used to connect to a second gas cylinder and to the suction boosting module via a pipeline; and;

[0014] A valve assembly for connecting the first cylinder to the suction and pressurization module, or for connecting the second cylinder to the suction and pressurization module.

[0015] Using the above technical solution, the recycling system of this application embodiment includes two steel cylinders (a first steel cylinder and a second steel cylinder), which can be understood as including two steel cylinder pipelines. The two steel cylinders are connected in parallel and switched with the booster pump through a valve assembly, which is equivalent to providing a dual-cylinder redundant system to ensure the continuity of production.

[0016] Specifically, in uninterrupted situations such as automotive production lines, when a cylinder (e.g., the first cylinder) triggers an empty cylinder alarm, the valve assembly connects the first cylinder's pipeline to the suction and pressurization module, thereby initiating the recycling process. At this time, the second cylinder is not involved in recycling and can provide refrigerant to the external liquid supply system at any time. Conversely, when the second cylinder triggers an alarm, the valve assembly connects its pipeline to the suction and pressurization module, allowing the second cylinder to enter the recycling process. This dual-cylinder redundancy design ensures that the recycling system always has one cylinder available to guarantee the material supply to the production line, while the other cylinder can be used for the recycling process described in this embodiment, simultaneously ensuring resource recovery and production line continuity.

[0017] Preferably, the gas-liquid separation and liquid storage module includes:

[0018] An exhaust tank, equipped with an exhaust valve, and connected to the suction booster module; and;

[0019] A recycling tank is connected to the exhaust tank.

[0020] Preferably, it further includes:

[0021] A liquid level sensor is installed in the exhaust tank to detect the liquid level of the liquefied refrigerant in the exhaust tank;

[0022] The first pressure switch is used to detect the pressure inside the exhaust canister.

[0023] Using the above technical solution, in this embodiment, a liquid level sensor is used to monitor the liquid level in the exhaust tank in real time, and a first pressure switch is used to monitor the pressure in the exhaust tank in real time, thereby providing a basis for switching between the exhaust state and the recovery state of the exhaust tank in the recovery system. Through the dual-parameter control logic of the liquid level sensor and the first pressure switch, misjudgment of a single parameter (e.g., high pressure without gas, or insufficient liquid level but erroneous exhaust) can be effectively avoided, ensuring the accuracy and efficiency of the exhaust action in the exhaust state, and effectively improving the reliability of the recovery system and the quality of the recovered liquid refrigerant.

[0024] Preferably, when the gas pressure in the exhaust tank is not less than a first preset pressure and the liquid level of the liquefied refrigerant in the exhaust tank is lower than a preset level, the control unit is adapted to open the exhaust valve and maintain it for a first preset time and to stop the suction boosting module from working for a first preset time.

[0025] Preferably, the first preset pressure is 13 bar.

[0026] Preferably, when the level of liquefied refrigerant in the exhaust tank reaches or exceeds a preset level, the control unit is adapted to stop the suction and pressurization module from working, thereby completing the recovery of residual refrigerant from the cylinder.

[0027] Preferably, it further includes:

[0028] The second pressure switch is used to detect the pressure inside the gas cylinder.

[0029] Using the above technical solution, the second pressure switch, for example, is installed on the pipeline of the gas cylinder, which can effectively and accurately detect changes in the gas pressure inside the gas cylinder and execute the logic of "stopping recycling when the gas pressure inside the gas cylinder is lower than the second preset pressure" as described later.

[0030] Preferably, when the gas pressure in the cylinder is less than the second preset pressure, the control unit is adapted to stop the suction and pressurization module from working, thereby completing the recovery of the residual refrigerant in the cylinder.

[0031] Using the above technical solution, when the gas pressure inside the cylinder is lower than the second preset pressure, the control unit controls the suction and pressurization module to stop working. That is, by detecting the pressure at the source of the cylinder, it can be directly reflected whether the refrigerant inside the cylinder has been effectively evacuated. In other words, when the gas pressure inside the cylinder drops to the second preset pressure, it indicates that the recoverable gas-liquid coexisting residual refrigerant inside the cylinder has been relatively exhausted. At this time, the booster pump stops, indicating that the recovery process has ended.

[0032] Preferably, the second preset pressure is any value between 200 mbar and 500 mbar.

[0033] Preferably, the gas-liquid separation and storage module is also connected to the liquid supply system;

[0034] When the recovery system completes the recovery of the residual refrigerant from the cylinder, the recovery system is configured to have a first liquid supply state and a second liquid supply state.

[0035] In the first liquid supply state, the gas pressure of the gas-liquid separation and liquid storage module is greater than the third preset pressure, and the refrigerant in the gas-liquid separation and liquid storage module is output to the external liquid supply system.

[0036] In the second liquid supply state, the gas pressure of the gas-liquid separation and liquid storage module is less than the fourth preset pressure, and the refrigerant in the non-empty cylinder is output to the external liquid supply system; wherein, the third preset pressure is greater than the fourth preset pressure.

[0037] Using the above technical solution, in this embodiment of the application, the liquid refrigerant recovered by the recovery system needs to be supplied to an external liquid supply system. Therefore, when the recovery system completes the recovery of the residual refrigerant in the cylinder, this embodiment of the application also includes two liquid supply states.

[0038] In the first liquid supply state, the gas pressure in the gas-liquid separation and storage module is greater than the third preset pressure, indicating that a certain amount of liquid refrigerant has accumulated in the recovered liquid refrigerant in the gas-liquid separation and storage module without affecting the extracted gas. In other words, the gas-liquid separation and storage module has collected a sufficient amount of liquid refrigerant for use by the external liquid supply system. At this time, the recovery system prioritizes delivering the liquid refrigerant in the gas-liquid separation and storage module to the external liquid supply system.

[0039] In the second liquid supply state, the gas pressure of the gas-liquid separation and liquid storage module is less than the fourth preset pressure, indicating that the amount of gas accumulated in the liquid refrigerant recovered in the gas-liquid separation and liquid storage module that will not affect the extraction is insufficient. This means that the amount of liquid refrigerant recovered in the gas-liquid separation and liquid storage module is insufficient. At this time, the recovery system prioritizes transporting the liquid refrigerant in the cylinder to the external liquid supply system. It should be noted that the cylinder being extracted at this time is not empty.

[0040] Therefore, by switching between the first liquid supply state and the second liquid supply state, the continuity and stability of the liquid supply to the production line can be effectively guaranteed.

[0041] Preferably, the third preset pressure is 13 bar, and the fourth preset pressure is 6 bar.

[0042] Preferably, the refrigerant is a hydrofluoroolefin refrigerant.

[0043] Preferably, it further includes:

[0044] The hydraulic cabinet houses the suction booster module and the gas-liquid separation and storage module.

[0045] A concentration sensor, installed inside the hydraulic cabinet, is used to detect the concentration of leaked refrigerant gas inside the hydraulic cabinet;

[0046] When the detected concentration of the leaked gas exceeds a preset safety alarm value, the control unit triggers a leak alarm signal.

[0047] By adopting the above technical solution, on the one hand, the hydraulic cabinet can confine the suction and pressurization module, gas-liquid separation and liquid storage module that may leak within a closed structure, and on the other hand, it can integrate the main recovery system components together, making maintenance easier.

[0048] On the other hand, when the recovery system of this application embodiment is applied to an explosive refrigerant, taking hydrofluoroolefin (HFO) refrigerant as an example, it will rapidly vaporize after leakage and mix with air to form a flammable gas. The concentration sensor installed in the hydraulic cabinet can monitor the concentration of HFO gas in the hydraulic cabinet in real time, thereby avoiding potential safety accidents and effectively improving the safety of the recovery system.

[0049] Preferably, it further includes:

[0050] An explosion-proof fan is used to discharge leaked refrigerant gas from the hydraulic cabinet;

[0051] A wind speed sensor is used to detect the wind speed of the explosion-proof fan;

[0052] When the detected wind speed is lower than the set safety value, the control unit issues an alarm for low fan speed.

[0053] Even with the above technical solutions, if leaked gas accumulates inside the hydraulic cabinet, the risk still exists, even with concentration detection and alarms. Adding explosion-proof fans can discharge leaked gas into the recovery system. For example, forced ventilation can be used in potential leak areas such as hydraulic cabinets to promptly remove and discharge potentially explosive gases to safe areas (such as outside the workshop roof), thereby effectively reducing the concentration of flammable gases inside the cabinet and fundamentally lowering the safety risk factor.

[0054] The present invention also discloses a method for recovering refrigerant, applied to a refrigerant recovery system, wherein:

[0055] The refrigerant recovery system is used to recover residual refrigerant in the cylinder, which is used to supply refrigerant to the refrigerant supply system on the automobile production line, and includes:

[0056] The exhaust canister is equipped with an exhaust valve;

[0057] A booster pump is connected between the gas cylinder and the exhaust tank;

[0058] A recovery tank, connected to the exhaust tank;

[0059] The refrigerant recovery method includes:

[0060] Obtain the empty cylinder alarm signal, wherein the empty cylinder alarm signal indicates that there is residual refrigerant in the cylinder;

[0061] Start the booster pump to deliver the residual refrigerant to the exhaust tank;

[0062] If the air pressure in the exhaust tank is not less than a first preset pressure and the liquid level in the exhaust tank is lower than a preset liquid level, the exhaust valve is controlled to open for a first preset time.

[0063] If the liquid level in the exhaust tank reaches or exceeds a preset level, or if the gas pressure inside the cylinder is less than a second preset pressure, the booster pump is controlled to stop working.

[0064] Preferably, it further includes:

[0065] Determine that the gas pressure in the exhaust tank is not less than the third preset pressure, and control the delivery of the refrigerant in the recovery tank to the liquid supply system;

[0066] If the gas pressure in the exhaust tank is determined to be less than the fourth preset pressure, control the cessation of supplying refrigerant from the recovery tank to the liquid supply system, wherein the third preset pressure is greater than the fourth preset pressure.

[0067] Embodiments of the present invention also disclose a computer storage medium, including a memory and a processor, wherein the memory is adapted to store computer instructions, and the processor is adapted to execute the refrigerant recovery method described in any of the above embodiments when running the computer instructions.

[0068] The present invention also discloses a computer program product, including a computer program / instructions, which, when executed by a processor, implement the refrigerant recovery method described in any of the above embodiments. Attached Figure Description

[0069] Figure 1 shows a schematic diagram of the refrigerant recovery system according to an embodiment of the present invention.

[0070] Figure 2 shows a flowchart of the refrigerant recovery method according to an embodiment of the present invention.

[0071] Figure 3 shows a block diagram of the control unit provided in an embodiment of the present invention.

[0072] Figure 4 shows a block diagram of a system-on-a-chip (SoC) provided in an embodiment of the present invention. Detailed Implementation

[0073] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a deep understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0074] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0075] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of the invention is usually placed in during use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0076] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0077] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0078] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0079] On the automobile manufacturing assembly line, when the refrigerant supply cylinder is pumped down to only a small amount (e.g., about 5%) of refrigerant remains, this small amount of refrigerant is often in a gas-liquid coexistence state, and the pressure inside the supply cylinder is low. This makes it difficult for the external supply system to extract the refrigerant, resulting in the supply cylinder with residual refrigerant being discarded, causing a waste of resources.

[0080] On the other hand, some types of air conditioning refrigerants pose an explosion risk. This embodiment will use hydrofluoroolefin (HFO) refrigerant as an example for further explanation. Although liquid HFO refrigerant itself does not directly burn or explode, if liquid HFO refrigerant leaks, it will quickly vaporize into HFO gas. HFO gas is flammable, and when it mixes with air, it will form a flammable gas environment. When the concentration of HFO gas is high, an explosion is likely to occur.

[0081] To address the aforementioned technical problems, referring to Figure 1, this application provides a refrigerant recovery system 100 (hereinafter referred to as "recovery system 100"). The core function of the recovery system 100 is that when the liquid supply system triggers an empty cylinder alarm, it can recover the residual refrigerant in the gas-liquid coexisting state inside the cylinder, process it, and then re-transport it to the liquid supply system, thereby achieving full utilization of the material.

[0082] The specific structure and working logic of the recycling system 100 of this application embodiment will be described in detail below with reference to the accompanying drawings.

[0083] Referring to Figure 1, in this embodiment of the application, the recycling system 100 mainly includes a cylinder connection module 10, a suction and pressurization module 20, a gas-liquid separation and storage module 30, a safety protection module 40, and a control unit.

[0084] Specifically, the cylinder connection module 10 is used to connect an external cylinder storing refrigerant to the suction and pressurization module 20. The cylinder connection module 10 of this embodiment includes at least one interface 110 for connecting to the cylinder storing refrigerant.

[0085] It should be noted that, in this embodiment of the application, when the refrigerant inside the cylinder can be drawn by the external liquid supply system and the production cycle is met, it indicates that the refrigerant inside does not need to be recycled. This state is referred to as "non-empty cylinder state" in this embodiment of the application.

[0086] When only a small amount of refrigerant remains in the cylinder (e.g., only about 5% refrigerant) and this small amount of refrigerant cannot be extracted by the external liquid supply system, or can be extracted by the external liquid supply system but cannot meet the production cycle, it indicates that the small amount of refrigerant is in a gas-liquid coexistence state. That is, the cylinder contains refrigerant gas that cannot be extracted or is liquid refrigerant that can be extracted smoothly. In this embodiment, this state is referred to as "empty cylinder state," and the small amount of refrigerant in the gas-liquid coexistence state is referred to as "residual refrigerant." It can be understood that the recycling system 100 in this embodiment is intended to recycle and process this residual refrigerant.

[0087] To ensure uninterrupted production, a dual-cylinder redundancy design is generally adopted. When one cylinder is empty, the system immediately switches to the other cylinder for liquid supply. As shown in Figure 1, the cylinder connection module 10 in the recycling system 100 of this embodiment also includes two cylinder connection interfaces: a first interface 111 and a second interface 112. It is understood that the number of cylinders is not limited to this; for example, one, three, four, or five cylinders can also be configured. The cylinder connection module 10 can also include a corresponding number of interfaces.

[0088] As shown in Figure 1, the first interface 111 is used to connect to a gas cylinder (such as the first gas cylinder) and is connected to the suction and pressurization module 20 through a pipeline. The second interface 112 is used to connect to another gas cylinder (such as the second gas cylinder) and is connected to the suction and pressurization module 20 through a pipeline.

[0089] For example, the cylinder connection module 10 also includes a valve assembly 150. The valve assembly 150 can selectively connect the first interface 111 or the second interface 112 to the downstream suction booster module 20 according to the control signal of the control unit.

[0090] As shown in the embodiment of Figure 1, the valve assembly 150 includes a first valve 151 and a second valve 152. The first valve 151 is disposed between the first interface 111 and the suction boosting module 20. The second valve 152 is disposed between the second interface 112 and the suction boosting module 20. According to the control signal from the control unit, the first valve 151 can be opened and the second valve 152 can be closed, so that the first interface 111 is connected to the suction boosting module 20, while the second interface 112 is not connected to the suction boosting module 20. The reverse is also true. The first valve 151 and the second valve 152 can be manual valves, pneumatic valves, electric valves, etc., and the present invention does not limit them.

[0091] In one or more embodiments, valve assembly 150 may include a three-way valve. This three-way valve can selectively connect either the first port 111 or the second port 112 to the downstream suction booster module 20 according to a control signal from the control unit. The three-way valve may be a manual valve, a pneumatic valve, an electric valve, etc., and the present invention is not limited thereto.

[0092] Furthermore, the suction and pressurization module 20 is used to extract refrigerant from the empty cylinder and pressurize and deliver the refrigerant and / or impurity gases (e.g., nitrogen) to the gas-liquid separation and storage module 30. The suction and pressurization module 20 in this embodiment includes a booster pump 120. The booster pump 120 can be a pneumatic booster pump, an electric booster pump, etc., and this invention does not limit this to any particular type.

[0093] As shown in Figure 1, the inlet end 120a of the booster pump 120 is selectively connected to the pipeline of the valve assembly 150 and the first interface 111, or the inlet end 120a of the booster pump 120 is selectively connected to the pipeline of the valve assembly 150 and the second interface 112. The outlet end 120b of the booster pump 120 is connected to the gas-liquid separation and liquid storage module 30.

[0094] In one or more embodiments, a second pressure switch 163 is provided on the pipeline between the cylinder connection module 10 and the suction boosting module 20 for detecting the pressure inside the cylinder.

[0095] In the recovery state, when the pressure detected by the second pressure switch 163 is less than the second preset pressure (e.g., 200 mbar), it indicates that the residual refrigerant in the cylinder has been completely removed. At this time, the pumping and pressurizing module 20 stops working, and the residual liquid recovery of the cylinder is completed.

[0096] Furthermore, the gas-liquid separation and storage module 30 is used to perform gas-liquid separation and storage of the refrigerant and / or impurity gas delivered from the suction and pressurization module 20. The gas-liquid separation and storage module 30 in this embodiment includes an exhaust tank 130 and a recovery tank 140.

[0097] The exhaust tank 130 is equipped with an exhaust valve 131 for discharging gaseous refrigerant and / or impurity gases. A recovery tank 140 is connected to the exhaust tank 130 and is used to store refrigerant. Simultaneously, the outlet end 120b of the booster pump 120 is connected to the exhaust tank 130 to transport residual refrigerant from the cylinder to the exhaust tank 130 for gas-liquid separation.

[0098] Specifically, when the liquid supply system triggers an empty cylinder alarm (taking the first cylinder as an example), it indicates that a small amount of residual refrigerant in a gas-liquid coexisting state remains in the first cylinder and cannot be extracted by the external liquid supply system. At this time, the first valve 151 connects the pipeline of the first cylinder to the inlet 120a of the booster pump 120, and then starts the booster pump 120 to pump the residual refrigerant in the first cylinder into the exhaust tank 130 for gas-liquid separation.

[0099] The exhaust tank 130 in this embodiment includes two operating states: exhaust state and recovery state. The switching between the exhaust state and the recovery state is based on real-time monitoring and logic control of the gas pressure and liquid level inside the exhaust tank 130.

[0100] When the gas pressure in the exhaust tank 130 is not less than a first preset pressure, and the liquid level of the liquefied refrigerant in the exhaust tank 130 is lower than a preset level, the exhaust tank 130 enters the exhaust state. At this time, the exhaust valve 131 is in the open state and remains open for a first preset time (e.g., 2 seconds). This allows the gaseous refrigerant and / or impurity gases in the exhaust tank 130 to be discharged from the recovery system 100 through the exhaust valve 131. In one or more embodiments, when the exhaust tank 130 is in the exhaust state, the suction booster module 20 stops operating.

[0101] Wherein, the gas pressure in the exhaust tank 130 is not less than the first preset pressure, and the liquid level in the exhaust tank 130 is lower than the preset liquid level, it means that due to the continuous operation of the booster pump 120 in the early stage, the residual refrigerant and / or impurity gas in the first steel cylinder is forced into the exhaust tank 130, causing the pressure in the exhaust tank 130 to rise. If no liquid is detected under high pressure, it indicates that the main accumulation in the exhaust tank 130 is gas (i.e., the gas phase part of the residual refrigerant and / or impurity gas), then the exhaust valve 131 is activated to discharge the gas.

[0102] With the exhaust valve 131 closed, the exhaust tank 130 is in a recovery state. In the recovery state, the exhaust tank 130 liquefies and seals the refrigerant supplied by the suction booster module 20.

[0103] In this system, the exhaust tank 130 is in a recovery state, and the booster pump 120 continuously operates, forcing the residual refrigerant and / or impurity gases from the first cylinder into the exhaust tank 130. When the partial pressure of the refrigerant in the exhaust tank 130 reaches its saturated vapor pressure, a portion of the refrigerant will liquefy and be stored in the recovery tank 140. When the residual refrigerant in the cylinder has been completely pumped back, or when the level of the liquefied refrigerant in the exhaust tank 130 reaches a preset level, the booster pump 120 stops operating, and the exhaust tank 130 remains in a recovery state to seal and maintain the pressure of the refrigerant within it.

[0104] It should be noted that the saturated vapor pressure of HFO refrigerant at 25°C is approximately 5.8 bar. This means that when the partial pressure of HFO in the exhaust canister 130 reaches 5.8 bar at 25°C, some of the HFO will liquefy, achieving gas-liquid equilibrium and maintaining the partial pressure of HFO at 5.8 bar. However, if the gas injected into the exhaust canister 130 contains impurities, these impurities will have a corresponding partial pressure within the exhaust canister 130, causing the total gas pressure within the exhaust canister 130 to exceed the saturated vapor pressure of HFO.

[0105] In one or more embodiments, the exhaust tank 130 is provided with a liquid level sensor 161. The liquid level sensor 161 is used to detect the liquid level inside the exhaust tank 130. The liquid level detected by the liquid level sensor 161 is the liquid level of the liquefied refrigerant inside the exhaust tank 130, which is compared with a preset liquid level.

[0106] For example, according to engineering practice, the preset liquid level can be set at about 2 / 3 of the total height of the tank from the bottom of the exhaust tank 130 (hereinafter referred to as the 2 / 3 of the exhaust tank 130). However, it is not limited to this. For example, the preset liquid level can also be set at about 3 / 5, 5 / 8, etc., of the total height of the tank from the bottom of the exhaust tank 130. The following description uses the preset liquid level of 2 / 3 of the exhaust tank 130 as an example.

[0107] In one or more embodiments, a first pressure switch 162 is provided between the recovery tank 140 and the external liquid supply system. The first pressure switch 162 is used to detect the air pressure in the pipeline between the recovery tank 140 and the liquid supply system. Since the exhaust tank 130 and the recovery tank 140 are connected by a pipeline, the air pressure detected by the first pressure switch 162 is also the air pressure inside the exhaust tank 130. It can be understood that the first pressure switch 162 can be set at any position where the air pressure inside the exhaust tank 130 can be measured. The air pressure detected by the first pressure switch 162 is the air pressure inside the exhaust tank 130 mentioned above, which is compared with a first preset pressure.

[0108] For example, according to engineering practice, the first preset pressure is preferably set to 13 bar, but it is not limited to this. For example, the first preset pressure can also be set to 11 bar, 12 bar, 13.1 bar, 13.5 bar, 14 bar, 16 bar, etc., as long as it is higher than the saturated vapor pressure of the refrigerant. The following description uses a first preset pressure of 13 bar as an example.

[0109] In other words, when the pressure detected by the first pressure switch 162 is not less than 13 bar, and the liquid level in the exhaust tank 130 is lower than 2 / 3 of the exhaust tank 130, it indicates that the exhaust tank 130 mainly contains the gas phase portion of the residual refrigerant and / or impurity gas. At this time, the exhaust tank 130 switches to the exhaust state.

[0110] Referring to Figure 1, in some possible implementations, when the exhaust tank 130 is in the recovery state and the gas pressure in the cylinder is less than the second preset pressure, it indicates that the residual refrigerant in the cylinder has been completely removed or recovered to the recovery tank 140. At this time, the booster pump 120 is in the stopped state.

[0111] For example, according to engineering practice, the second preset pressure is preferably set to 200 mbar to 500 mbar. For instance, the second preset pressure can preferably be 200 mbar, 207 mbar, 289 mbar, 300 mbar, 356 mbar, 400.6 mbar, 415.5 mbar, 499.7 mbar, or 500 mbar. This article uses a second preset pressure of 200 mbar as an example for illustration.

[0112] On the other hand, in this embodiment of the application, the recovery system 100 can work in conjunction with an external liquid supply system, that is, the outlet of the recovery tank 140 is connected to an external liquid supply system, so that the recovered liquid refrigerant can be reused.

[0113] Based on this, the recycling system 100 of this application embodiment is equipped with an exhaust tank 130, a booster pump 120 and a recycling tank 140 for the gas cylinder, and adopts control logic for the exhaust and recycling states of the exhaust tank 130, which can realize efficient and automated recycling of residual refrigerant in the gas cylinder.

[0114] In other words, the above-mentioned exhaust and recovery mechanism of the recovery system 100 can effectively solve the pain points of difficulty in extraction and material waste caused by the coexistence of gas and liquid in traditional steel cylinders. Through pressurization and intelligent exhaust, the originally discarded residual refrigerant is transformed into a usable resource, thereby significantly reducing material waste and production costs while ensuring that the liquid supply to the production line is not affected.

[0115] In some possible implementations, as described above, the recovery tank 140 can be connected to an external liquid supply system. To optimize energy efficiency, the recovery system 100 is configured with two intelligent liquid supply states after it has completed the recovery of residual refrigerant from the cylinder.

[0116] Specifically, in the first liquid supply state, if the gas pressure of the exhaust tank 130 is greater than the third preset pressure (e.g., 13 bar), the liquid refrigerant in the recovery tank 140 will be output to the external liquid supply system.

[0117] In the second liquid supply state, if the pressure in the exhaust tank 130 is less than the fourth preset pressure (e.g., 6 bar), the refrigerant in the non-empty cylinder is output to the external liquid supply system. At this time, the recovery system 100 prepares for the next cylinder recovery. The third preset pressure is greater than the fourth preset pressure.

[0118] In some possible implementations, the exhaust tank 130 is also equipped with a safety relief valve 170. When the pressure inside the exhaust tank 130 surges to 25 bar due to special reasons, the safety relief valve 170 safely relieves the pressure and discharges it into the factory exhaust duct leading directly to the roof, thereby protecting the pipeline and equipment.

[0119] Referring to Figure 1, as described above, the recycling system in this embodiment of the application further includes a security protection module 40.

[0120] Specifically, when the refrigerant in the cylinder is exemplarily selected as HFO refrigerant, if the HFO refrigerant leaks through any one or more of the booster pump 120, exhaust tank 130, recovery tank 140, and valve assembly 150, the HFO gas generated by vaporization in the air becomes explosive after reaching a certain concentration range (e.g., 6.2% to 12.3%). The safety protection module 40 of this application embodiment can provide safety protection measures for this.

[0121] In some possible implementations, in terms of component selection, any one or more of the following, including but not limited to the level sensor 161, the first pressure switch 162, the second pressure switch 163, and the valve assembly 150, are selected as explosion-proof components.

[0122] In some possible implementations, the exhaust tank 130, recovery tank 140, and valve assembly 150 of the recovery system 100 are the main high-pressure and leak-prone components. In the embodiments of this application, the exhaust tank 130, recovery tank 140, and valve assembly 150 are housed together in a sealed hydraulic cabinet (not shown in the figure, but those skilled in the art will understand that any sealed or semi-sealed cabinet falls within the protection scope of the embodiments of this application), which can confine potential leaks to a limited and controllable space.

[0123] In some possible implementations, the recovery system 100 of this application embodiment further includes a concentration sensor 164.

[0124] A concentration sensor 164 is installed inside the aforementioned hydraulic cabinet to detect refrigerant leaks in the exhaust tank 130, recovery tank 140, and valve assembly 150. Specifically, when the concentration sensor 164 detects a leaked gas concentration exceeding a preset safety alarm value, the control unit of the recovery system 100 triggers a leak alarm signal and stops all operations of the recovery system 100. Simultaneously, the alarm information is transmitted remotely to safety management personnel for timely safety checks.

[0125] In some possible implementations, the recovery system 100 further includes an explosion-proof fan 180 for discharging leaked refrigerant gas from the recovery system 100. That is, to further proactively reduce risk, the recovery system 100 is also equipped with an explosion-proof fan 180, which continuously ventilates and exhausts potential leak areas such as hydraulic cabinets 24 hours a day, directly discharging any potentially accumulated flammable gas to a safe area outside the workshop (such as the workshop roof), thereby effectively diluting and reducing the concentration of flammable gas inside the hydraulic cabinet.

[0126] For example, to ensure that the explosion-proof fan 180 is always in an effective working state, the recovery system 100 is also equipped with a wind speed sensor 165 to detect the wind speed of the explosion-proof fan 180. That is, when the wind speed sensor 165 detects that the wind speed of the explosion-proof fan 180 is lower than the set safety value, the control unit controls the recovery system 100 to trigger a "fan wind speed too low" alarm, reminding maintenance personnel to carry out timely maintenance, thereby building a second line of active safety defense.

[0127] Based on the recycling system 100 of this application embodiment, this application embodiment also provides a refrigerant recycling method.

[0128] Referring to Figure 2 and in conjunction with Figure 1, the refrigerant recovery method of this application embodiment includes the following steps:

[0129] Step S100: Obtain the empty cylinder alarm signal, wherein the empty cylinder alarm signal indicates that there is residual refrigerant in the cylinder.

[0130] In this step, when the external liquid supply system detects that the refrigerant in the first cylinder has been drawn down to about 5%, the remaining 5% of refrigerant is residual refrigerant in a gas-liquid coexistence state. At this time, the first cylinder triggers an empty cylinder alarm signal. After the control unit of the recycling system 100 (not shown in the figure, but can be integrated into the system PLC or host computer) continuously acquires the empty cylinder alarm signal, the control unit determines that the corresponding first cylinder needs to enter the waiting state for recycling and prepares to start the recycling process.

[0131] Step S200: Start the booster pump 120 to deliver the residual refrigerant to the exhaust tank 130.

[0132] Based on the above step S100, in this step, the control unit generates a control command according to the acquired empty bottle alarm signal and outputs the control command to the valve assembly 150. The valve assembly 150 switches the pipeline according to the control command, for example, connecting the pipeline of the first cylinder to the inlet 120a of the booster pump 120. Then, the control unit starts the booster pump 120. After the booster pump 120 is running, it provides a higher pumping force to overcome the high resistance of the gas in the residual refrigerant and pump the residual refrigerant in the first cylinder into the exhaust tank 130.

[0133] Step S300: Determine that the air pressure of the exhaust tank 130 is not less than the first preset pressure and the liquid level of the exhaust tank 130 is lower than the preset liquid level, and control the exhaust valve 131 to open for a first preset time.

[0134] Based on the above step S200, in this step, the air pressure and liquid level in the exhaust tank 130 are monitored in real time, and compared with the first preset pressure and preset liquid level by the control unit. When the air pressure in the exhaust tank 130 is not less than the first preset pressure (e.g., 13 bar) and the liquid level is lower than the preset liquid level (e.g., 2 / 3 of the exhaust tank 130), the exhaust valve 131 is controlled to open for a first preset time (e.g., 2 seconds).

[0135] For example, during the process of the booster pump 120 delivering residual refrigerant to the exhaust tank 130, the liquid level sensor 161 and the first pressure switch 162 monitor the state inside the exhaust tank 130 in real time, and the control unit continuously compares the monitoring data with the preset value.

[0136] When the first pressure switch 162 detects that the pressure inside the exhaust tank 130 has risen to a level not less than the first preset pressure (e.g., 13 bar), and the liquid level value fed back by the liquid level sensor 161 is still lower than the preset liquid level (e.g., 2 / 3 of the exhaust tank 130), the control unit determines that a large amount of gas (gaseous refrigerant and / or impurity gas) has accumulated in the tank. Subsequently, the control unit sends an opening command to the exhaust valve 131 to perform the exhaust operation. After exhausting for a first preset time (e.g., 2 seconds), the exhaust valve 131 is closed. At this time, the booster pump 120 continues to work. When the pressure inside the exhaust tank 130 reaches the first preset pressure again and the liquid level cannot be detected, the control unit continues to send an opening command to the exhaust valve 131 to perform the exhaust operation.

[0137] Step S400: If the liquid level of the exhaust tank reaches or exceeds the preset liquid level, or the gas pressure in the cylinder is less than the second preset pressure, control the booster pump 120 to stop working.

[0138] Based on step S300 above, in this step, the liquid level in the exhaust tank 130 is monitored in real time and compared with the preset liquid level by the control unit. When the liquid level in the exhaust tank 130 reaches or exceeds the preset liquid level (2 / 3 of the exhaust tank 130), the booster pump 120 is stopped, and the exhaust valve 131 remains closed to seal and maintain pressure for the refrigerant. In other words, at this time, the control unit determines that sufficient liquid refrigerant has been successfully separated and accumulated in the exhaust tank 130, and the recovery process is paused or stopped.

[0139] Simultaneously, the second pressure switch 163 monitors the gas pressure inside the cylinder in real time and compares it with the second preset pressure via the control unit. When the gas pressure inside the cylinder is lower than the second preset pressure, the booster pump 120 stops working, and the exhaust valve 131 remains closed to maintain pressure and seal the refrigerant. In other words, at this point, the control unit determines that the recyclable residual refrigerant in the first cylinder has been essentially completely removed, and the recycling of that cylinder is complete.

[0140] Step S500: Determine that the gas pressure of the exhaust tank 130 is not less than the third preset pressure, and control the delivery of refrigerant in the recovery tank 140 to the liquid supply system.

[0141] Based on the above step S400, in this step, the pipeline between the recovery tank 140 and the liquid supply system is opened, the pipeline between the cylinder and the liquid supply system is closed, and the refrigerant in the recovery tank 140 is delivered to the liquid supply system.

[0142] Step S600: Determine that the gas pressure in the exhaust tank 130 is less than the fourth preset pressure, and control to stop the delivery of refrigerant in the recovery tank 140 to the liquid supply system.

[0143] Based on the above step S500, in this step, the pipeline between the recovery tank 140 and the liquid supply system is closed, and the pipeline between the cylinder and the liquid supply system is opened to deliver the refrigerant in the cylinder to the liquid supply system.

[0144] In summary, the refrigerant recovery system 100 and recovery method provided in this application, through integrated modular design, intelligent state switching logic, and multiple safety protection measures, successfully achieve efficient, automatic, and safe recovery of residual refrigerant in steel cylinders, effectively reducing material costs and waste disposal costs. At the same time, it resolves the contradiction between continuous liquid supply and resource recovery in automotive production lines, and provides safety assurance for handling potentially hazardous refrigerants, thus possessing significant industrial application value.

[0145] Furthermore, the present invention also provides a computer storage medium, including a memory and a processor, wherein the memory is adapted to store computer instructions, and the processor is adapted to execute the refrigerant recovery method described in any of the above embodiments when running the computer instructions.

[0146] Referring to FIG3, FIG3 exemplarily illustrates a block diagram of a control unit 600 according to one embodiment of the present application. The control unit 600 is, for example, an industrial control computer, a host computer, a PLC control system, etc. The control unit 600 may include one or more processors 601 coupled to a controller hub 603. In at least one embodiment, the controller hub 603 communicates with the processor 601 via a multi-branch bus such as a Front Side Bus (FSB), a point-to-point interface such as a QuickPath Interconnect (QPI), or a similar network interface 606. The processor 601 executes instructions controlling general types of data processing operations. In one embodiment, the controller hub 603 includes, but is not limited to, a Graphics & Memory Controller Hub (GMCH) (not shown) and an Input / Output Hub (IOH) (which may be on a separate chip) (not shown), wherein the GMCH includes memory and a graphics controller and is coupled to the IOH.

[0147] The control unit 600 may also include a coprocessor 602 and a memory 604 coupled to the controller hub 603. Alternatively, one or both of the memory and the GMCH may be integrated within the processor, with the memory 604 and the coprocessor 602 directly coupled to the processor 601 and the controller hub 603, which is located on a single chip with the IOH.

[0148] Memory 604 may be, for example, Dynamic Random Access Memory (DRAM), Phase Change Memory (PCM), or a combination of both. Memory 604 may include one or more tangible, non-transitory computer-readable media for storing data and / or instructions. The computer-readable storage medium stores instructions, specifically, temporary and permanent copies of those instructions. These instructions may include, when executed by at least one of the processors, instructions that cause control unit 600 to implement the refrigerant recovery method shown in FIG2. When the instructions are executed on a computer, they cause the computer to perform the method disclosed in any of the above embodiments or combinations thereof to assign the current contract to an operator.

[0149] In one embodiment, the coprocessor 602 is a dedicated processor, such as, for example, a high-throughput MIC (Many Integrated Core) processor, a network or communication processor, a compression engine, a graphics processor, a GPGPU (General-purpose computing on graphics processing units), or an embedded processor, etc. Optional properties of the coprocessor 602 are indicated by dashed lines in Figure 3.

[0150] In one embodiment, the control unit 600 may further include a network interface (NIC) 606. The network interface 606 may include a transceiver for providing a radio interface to the control unit 600, thereby enabling communication with any other suitable device, such as a front-end module, antenna, etc. In various embodiments, the network interface 606 may be integrated with other components of the control unit 600. The network interface 606 can implement the functionality of the communication unit in the above embodiments.

[0151] The control unit 600 may further include an input / output (I / O) device 605. I / O 605 may include: a user interface designed to allow a user to interact with the control unit 600; a peripheral component interface designed to allow peripheral components to also interact with the control unit 600; and / or sensors designed to determine environmental conditions and / or location information relevant to the control unit 600.

[0152] It is worth noting that Figure 3 is merely exemplary. That is, although Figure 3 shows the control unit 600 including multiple devices such as a processor 601, a controller hub 603, and a memory 604, in actual applications, devices using the methods of this application may include only a subset of the devices in the control unit 600; for example, it may only include the processor 601 and the network interface 606. The nature of the optional devices in Figure 3 is shown with dashed lines.

[0153] Referring now to FIG4, FIG4 exemplarily illustrates a block diagram of a SoC (System on Chip) 700 according to an embodiment of the present application. In FIG4, similar components have the same reference numerals. Additionally, dashed boxes represent optional features of more advanced SoCs. In FIG4, the SoC includes: an interconnect unit 750 coupled to a processor 601; a system proxy unit 780; a bus controller unit 790; an integrated memory controller unit 740; a group or one or more coprocessors 602, which may include integrated graphics logic, an image processor, an audio processor, and a video processor; a static random-access memory (SRAM) unit 730; and a direct memory access (DMA) unit 760. In one embodiment, the coprocessor 602 includes a dedicated processor, such as, for example, a network or communication processor, a compression engine, a GPGPU (General-purpose computing on graphics processing units), a high-throughput MIC processor, or an embedded processor, etc.

[0154] Static Random Access Memory (SRAM) cell 730 may include one or more tangible, non-transitory computer-readable media for storing data and / or instructions. The computer-readable storage medium stores instructions, specifically, temporary and permanent copies of those instructions. These instructions may include instructions that, when executed by at least one processor, cause the SoC to implement the refrigerant recovery method shown in FIG2. When the instructions are executed on a computer, they cause the computer to perform the methods disclosed in the above embodiments.

[0155] This application also provides a computer program product for implementing the refrigerant recovery method provided in the above embodiments.

[0156] Various embodiments of the mechanisms disclosed in this application can be implemented in hardware, software, firmware, or combinations of these implementation methods. Embodiments of this application can be implemented as computer program modules or module code executable on a programmable system, the programmable system including at least one processor, a storage system (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device.

[0157] Computer program modules or module code can be applied to input instructions to perform the functions described in this application and generate output information. The output information can be applied to one or more output devices in a known manner. For the purposes of this application, the processing system includes any system having a processor such as, for example, a digital signal processor (DSP), a microcontroller, an application-specific integrated circuit (ASIC), or a microprocessor.

[0158] Module code can be implemented using a high-level modular language or an object-oriented programming language to communicate with the processing system. Assembly language or machine language can also be used to implement module code when needed. In fact, the mechanisms described in this application are not limited to any particular programming language. In either case, the language can be a compiled language or an interpreted language.

[0159] In some cases, the disclosed embodiments may be implemented in hardware, firmware, software, or any combination thereof. The disclosed embodiments may also be implemented as instructions carried or stored thereon on one or more temporary or non-temporary machine-readable (e.g., computer-readable) storage media, which may be read and executed by one or more processors. For example, the instructions may be distributed via a network or through other computer-readable media. Therefore, machine-readable media may include any mechanism for storing or transmitting information in a machine-readable (e.g., computer-readable) form, including but not limited to floppy disks, optical disks, optical discs, magneto-optical disks, read-only memory (ROM), random access memory (RAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic cards or optical cards, flash memory, or tangible machine-readable storage for transmitting information (e.g., carrier waves, infrared signals, digital signals, etc.) using the Internet in the form of electrical, optical, acoustic, or other forms of propagated signals. Therefore, machine-readable media include any type of machine-readable medium suitable for storing or transmitting electronic instructions or information in a machine-readable (e.g., computer-readable) form.

[0160] While the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the invention to these descriptions. Various changes in form and detail can be made by those skilled in the art, including several simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

1. A refrigerant recovery system for recovering residual refrigerant from a steel cylinder used to supply refrigerant to a refrigerant supply system on an automotive production line, characterized in that... The system includes a cylinder connection module, a suction and pressurization module, a gas-liquid separation and storage module, and a control unit. The cylinder connection module connects the cylinder to the suction and pressurization module. The control unit, upon receiving an empty cylinder alarm, controls the suction and pressurization module to draw residual refrigerant and / or impurity gas from the cylinder to the gas-liquid separation and storage module. The gas-liquid separation and storage module performs gas-liquid separation and storage of the refrigerant and / or impurity gas supplied by the suction and pressurization module. The gas-liquid separation and storage module is also connected to the liquid supply system. When the recovery... The system completes the recovery of residual refrigerant from the gas cylinder. The recovery system is configured to have a first liquid supply state and a second liquid supply state. In the first liquid supply state, the gas pressure of the gas-liquid separation and storage module is greater than a third preset pressure, and the refrigerant in the gas-liquid separation and storage module is output to the external liquid supply system. In the second liquid supply state, the gas pressure of the gas-liquid separation and storage module is less than a fourth preset pressure, and the refrigerant in the non-empty cylinder is output to the external liquid supply system. The third preset pressure is greater than the fourth preset pressure.

2. The refrigerant recovery system according to claim 1, characterized in that, The cylinder connection module includes: a first interface for connecting to a first cylinder and connecting to the suction and pressurization module via a pipeline; a second interface for connecting to a second cylinder and connecting to the suction and pressurization module via a pipeline; and a valve assembly for connecting the first cylinder to the suction and pressurization module, or connecting the second cylinder to the suction and pressurization module.

3. The refrigerant recovery system according to claim 1, characterized in that, The gas-liquid separation and storage module includes: an exhaust tank equipped with an exhaust valve and connected to the suction and pressurization module; and a recovery tank connected to the exhaust tank.

4. The refrigerant recovery system according to claim 3, characterized in that, Also includes: A liquid level sensor is installed in the exhaust tank to detect the liquid level of the liquefied refrigerant in the exhaust tank; The first pressure switch is used to detect the pressure inside the exhaust canister.

5. The refrigerant recovery system according to claim 3 or 4, characterized in that, When the gas pressure in the exhaust tank is not less than a first preset pressure and the liquid level of the liquefied refrigerant in the exhaust tank is lower than a preset level, the control unit is adapted to open the exhaust valve and maintain it for a first preset time and to stop the suction boosting module from working for a first preset time.

6. The refrigerant recovery system according to claim 5, characterized in that, The first preset pressure is 13 bar.

7. The refrigerant recovery system according to claim 3 or 4, characterized in that, When the level of liquefied refrigerant in the exhaust tank reaches or exceeds a preset level, the control unit is adapted to stop the suction and pressurization module from working, thereby completing the recovery of residual refrigerant from the cylinder.

8. The refrigerant recovery system according to claim 1, characterized in that, Also includes: The second pressure switch is used to detect the pressure inside the gas cylinder.

9. The refrigerant recovery system according to claim 8, characterized in that, When the gas pressure in the cylinder is less than the second preset pressure, the control unit is adapted to stop the suction and pressurization module from working, thereby completing the recovery of the residual refrigerant in the cylinder.

10. The refrigerant recovery system according to claim 9, characterized in that, The second preset pressure is any value between 200 mbar and 500 mbar.

11. The refrigerant recovery system according to claim 1, characterized in that, The third preset pressure is 13 bar, and the fourth preset pressure is 6 bar.

12. The refrigerant recovery system according to claim 1, characterized in that, The refrigerant is a hydrofluoroolefin refrigerant.

13. The refrigerant recovery system according to claim 1 or 12, characterized in that, It also includes: a hydraulic cabinet, in which the suction boosting module and the gas-liquid separation and storage module are housed; a concentration sensor, located inside the hydraulic cabinet, for detecting the concentration of leaked refrigerant gas inside the hydraulic cabinet; when the detected concentration of leaked gas exceeds a preset safety alarm value, the control unit triggers a leak alarm signal.

14. The refrigerant recovery system according to claim 13, characterized in that, Also includes: An explosion-proof fan is used to discharge leaked refrigerant gas from the hydraulic cabinet; A wind speed sensor is used to detect the wind speed of the explosion-proof fan; when the detected wind speed is lower than a set safety value, the control unit issues an alarm for low fan speed.

15. A method for recovering refrigerant, characterized in that, A refrigerant recovery system is provided, wherein: the refrigerant recovery system is used to recover residual refrigerant in a gas cylinder, the gas cylinder being used to supply refrigerant to a refrigerant supply system on an automotive production line; the system includes: an exhaust canister equipped with an exhaust valve; a booster pump connected between the gas cylinder and the exhaust canister; a recovery tank connected to the exhaust canister; the recovery tank being connected to an external refrigerant supply system; when the recovery system completes the recovery of residual refrigerant from the gas cylinder, the recovery system is configured to have a first refrigerant supply state and a second refrigerant supply state; the refrigerant recovery method includes: acquiring an empty gas cylinder alarm signal, wherein the empty gas cylinder alarm signal indicates that there is residual refrigerant in the gas cylinder; activating the booster pump to... Residual refrigerant is delivered to the exhaust tank; if the pressure in the exhaust tank is not less than a first preset pressure and the liquid level in the exhaust tank is lower than a preset liquid level, the exhaust valve is controlled to open for a first preset time; if the liquid level in the exhaust tank reaches or exceeds the preset liquid level, or the pressure inside the cylinder is less than a second preset pressure, the booster pump is controlled to stop working; in the first liquid supply state, if the pressure in the exhaust tank is greater than a third preset pressure, the liquid refrigerant in the recovery tank is output to an external liquid supply system; in the second liquid supply state, if the pressure in the exhaust tank is less than a fourth preset pressure, the refrigerant in the non-empty cylinder is output to an external liquid supply system; wherein, the third preset pressure is greater than the fourth preset pressure.

16. A computer storage medium, characterized in that, The device includes a memory and a processor, the memory being adapted to store computer instructions, and the processor being adapted to execute the refrigerant recovery method of claim 15 when running the computer instructions.

17. A computer program product, characterized in that, Includes a computer program / instructions that, when executed by a processor, implement the refrigerant recovery method of claim 15.

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