Chiller circulating fluid recovery system and method

Abstract

The application provides a chiller circulating liquid recovery system and method, the system comprises a water tank and a refrigeration module connected by an internal pipeline, the water tank and the refrigeration module are also connected to an external load through a circulating pipeline; a purge module is arranged on the circulating pipeline of the refrigeration module input to the external load; the purge module comprises a plurality of one-way electromagnetic valves and a dry compressed air pipeline. When the circulating liquid is recovered, first, open the external load passage by controlling the valve, and then use compressed air to blow the residual liquid in the external pipeline back to the water tank; then, open the internal refrigeration module passage by controlling the valve, and then blow the residual liquid in the internal pipeline back to the water tank. The blowing process is monitored and feedback controlled in real time by first and second humidity sensors. The application realizes automatic and lossless recovery of the circulating liquid, eliminates liquid leakage and volatilization during shutdown maintenance, reduces operation and maintenance costs, and guarantees continuous operation of the production line.

Description

Technical Field

[0001] This invention belongs to the field of temperature-controlled chiller technology, and particularly relates to a chiller circulating liquid recovery system and method. Background Technology

[0002] With the continuous improvement of industrial automation and intelligence, chillers, as core refrigeration equipment to ensure stable industrial production, are finding increasingly wider applications. Especially in precision manufacturing processes such as semiconductor etching, the equipment typically needs to maintain operating temperatures below zero degrees Celsius. Under such low-temperature conditions, to prevent the circulating medium from freezing, the industry commonly uses electronic fluorinated liquids as the heat transfer fluid.

[0003] However, electronic fluorinated fluids are not only expensive but also highly volatile. In practical applications, when the chiller is shut down or external pipelines need maintenance or disassembly, the residual liquid inside the pipes is often difficult to recover effectively and is prone to evaporation. This directly leads to the ineffective loss of expensive circulating fluid, significantly increasing maintenance costs. Furthermore, the evaporated gases are easily captured by highly sensitive sensors around the production line, triggering false alarms and forcing production interruptions. This problem seriously affects the continuous operation efficiency and stability of the equipment.

[0004] Existing patent CN121855115A discloses a semiconductor temperature control system, comprising: a main pipeline including a circulating liquid tank, a pump body, and a heater connected in sequence; a heat exchanger, the inlet end of the heat exchanger's heat release path connected to the outlet end of the pump body, and the outlet end of the heat exchanger's heat release path connected to the inlet end of the heater; and a recovery unit, the circulating liquid tank having a steam outlet and a reflux outlet, the inlet end of the recovery unit's heat release path connected to the steam outlet, the outlet end of the recovery unit's heat release path connected to the reflux outlet, the inlet end of the recovery unit's heat absorption path connected to the inlet end of the heat exchanger's heat absorption path, and the outlet end of the recovery unit's heat absorption path connected to the outlet end of the heat exchanger's heat absorption path. This allows for the recovery and reuse of fluorinated liquid. Summary of the Invention

[0005] Currently, in existing chiller technology, after operation stops, the liquid in the circulating pipes cannot automatically flow back to the water tank; the user must manually disassemble the pipes to drain the liquid. This operation is not only cumbersome but also prone to leakage due to improper handling, resulting in unnecessary waste of expensive circulating fluid and significantly increasing equipment maintenance costs. Furthermore, the gas produced by the evaporation of leaked liquid is easily detected by highly sensitive sensors around the production line, triggering false alarms and potentially causing production interruptions in severe cases.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: a chiller circulating liquid recovery system, including a water tank and a refrigeration module connected by internal pipelines, the water tank and the refrigeration module are also connected to an external load through a circulation pipeline; a purging module is provided on the circulation pipeline from the refrigeration module to the external load; the purging module includes several one-way solenoid valves and a dry compressed air pipeline.

[0007] Specifically, the dry compressed air pipeline is connected to the access point of the circulation pipeline through a one-way solenoid valve; two one-way solenoid valves in opposite directions are connected in parallel between the refrigeration module and the access point of the circulation pipeline; and a one-way solenoid valve connecting the access point of the circulation pipeline to the external load is provided between the access point of the circulation pipeline and the external load.

[0008] Specifically, a water pump is installed on the internal pipeline, and two one-way solenoid valves in opposite directions are connected in parallel between the water tank and the refrigeration module. The one-way solenoid valve from the refrigeration module to the water tank is also equipped with a first humidity sensor.

[0009] Specifically, the water tank is equipped with two one-way valves that operate in opposite directions to balance the air pressure of the system.

[0010] Specifically, a second humidity sensor and a one-way solenoid valve are installed on the circulation pipeline between the external load and the water tank.

[0011] The present invention also provides a method for recovering circulating liquid from a chiller, applied to the aforementioned chiller circulating liquid recovery system, comprising the following steps: S1. Turn off the chiller, open the three one-way solenoid valves that connect the dry compressed air pipeline to the access point, the access point to the external load, and the external load to the water tank, close the other one-way solenoid valves, start the purging module to purge the circulation pipeline, and purge the residual liquid in the circulation pipeline to the water tank. S2. Connect the dry compressed air pipeline to the access point, the access point to the refrigeration module, and the one-way solenoid valve connecting the refrigeration module to the water tank. Close the other one-way solenoid valves and start the purging module to purge the internal pipeline and purge the residual liquid in the internal pipeline to the water tank.

[0012] Specifically, during the continuous purging process of the purging module in S1, the second humidity sensor determines whether the pipeline is dry. When the feedback value of the second humidity sensor is lower than the set threshold, step S2 is executed.

[0013] Specifically, during the continuous purging process of the S2 purging module, the first humidity sensor determines whether the pipeline is dry. When the feedback value from the second humidity sensor is lower than the set threshold, the purging work of circulating liquid recovery is completed.

[0014] Specifically, during normal operation of the chiller, only four one-way solenoid valves are opened: one connecting the water tank to the refrigeration module, one connecting the refrigeration module to the connection point, one connecting the connection point to the external load, and one connecting the external load to the water tank. The other one-way solenoid valves are closed.

[0015] Specifically, during normal operation of the chiller, the air pressure of the system is dynamically balanced through two one-way valves with opposite directions installed on the water tank.

[0016] The beneficial effects of this invention are that, through multi-valve logic control and a staged purging strategy integrated within the chiller, residual electronic fluorinated liquid in both external and internal pipelines is automatically recovered after shutdown, eliminating the need for manual disassembly of pipelines and significantly reducing the loss of expensive circulating fluid and labor maintenance costs. Combined with closed-loop feedback from a humidity sensor, the purging duration is precisely controlled, avoiding compressed air waste; the bidirectional pressure balance structure ensures the stability of normal equipment operation. The overall solution of this invention fundamentally avoids the risk of sensor false alarms and production interruptions caused by liquid leakage, demonstrating outstanding practical value in improving operational convenience, economy, and operational reliability. Attached Figure Description

[0017] Figure 1 This is a diagram of the pipeline structure of the present invention.

[0018] Figure 2 This is a flowchart of the method of the present invention.

[0019] In the diagram, 1 is the first solenoid valve, 2 is the second solenoid valve, 3 is the third solenoid valve, 4 is the fourth solenoid valve, 5 is the fifth solenoid valve, 6 is the sixth check valve, 7 is the seventh solenoid valve, 8 is the eighth solenoid valve, 9 is the ninth check valve, 10 is the tenth check valve, 11 is the first humidity sensor, 12 is the second humidity sensor, 13 is the connection point, 14 is the water pump, 15 is the refrigeration module, 16 is the dry compressed air pipeline, 17 is the external load, 18 is the water tank, and 19 is the manual valve. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] Example 1: A chiller circulating liquid recovery system includes a water tank and a refrigeration module connected by internal pipelines. The water tank and the refrigeration module are also connected to an external load through a circulation pipeline. A purging module is provided on the circulation pipeline from the refrigeration module to the external load. The purging module includes several one-way solenoid valves and a dry compressed air pipeline.

[0022] This embodiment also provides a method for recovering chiller circulating liquid, applied to the above-mentioned chiller circulating liquid recovery system, including the following steps: S1. Turn off the chiller, open the three one-way solenoid valves that connect the dry compressed air pipeline to the access point 13, the access point 13 to the external load, and the external load to the water tank, close the other one-way solenoid valves, start the purging module to purge the circulation pipeline, and purge the residual liquid in the circulation pipeline to the water tank. S2. Connect the dry compressed air pipeline to access point 13, access point 13 to the refrigeration module, open the one-way solenoid valve of the refrigeration module to the water tank, close the other one-way solenoid valves, start the purging module to purge the internal pipeline, and purge the residual liquid in the internal pipeline to the water tank.

[0023] like Figure 2 As shown, a logic network consisting of multiple one-way solenoid valves is installed on the circulation pipeline between the refrigeration module and the external load. Specifically, the dry compressed air pipeline is connected to the access point 13 of the circulation pipeline through a one-way solenoid valve; between the refrigeration module and the access point 13 of the circulation pipeline, two one-way solenoid valves with opposite directions (i.e., the third solenoid valve 3 and the fourth solenoid valve 4) are connected in parallel. The cooperation of these two valves can control the flow direction of the fluid between the refrigeration module and the water tank during the purging operation.

[0024] Between the connection point 13 of the circulation pipeline and the external load, there is a one-way solenoid valve (i.e., the fifth solenoid valve 5) that leads from the connection point 13 to the external load; and on the return pipeline that leads from the external load to the water tank, there is a one-way solenoid valve (i.e., the eighth solenoid valve 8) that leads from the external load to the water tank, and a second humidity sensor 12 is located nearby.

[0025] When circulating liquid recovery from the chiller is required, the chiller must first be shut down. After the chiller is shut down, the user can initiate the waste liquid recovery program via the control panel. First, solenoid valves 1, 2, 3, and 4 close, while solenoid valves 5 and 8 open. Then, solenoid valve 7 opens, and the purging module begins its purging operation, with external dry compressed air entering the circulation loop through the pipeline. During this process, check valve 6 allows only unidirectional fluid flow, effectively preventing backflow of residual liquid in the pipeline. Driven by the compressed air, the residual waste liquid in the external pipeline is gradually purged into the water tank via the pathway consisting of "connection point 13 -> fifth solenoid valve 5 -> external load -> eighth solenoid valve 8 -> water tank".

[0026] During the purging process, the system does not blindly perform fixed-time purging. Instead, it monitors the humidity (or residual liquid) of the discharged gas in real time using the second humidity sensor 12 (located near the eighth check valve). If the feedback value of the second humidity sensor 12 is higher than the set threshold, it indicates that there is still a large amount of liquid residue in the external pipeline. The control system maintains the current valve state, continues purging, and returns to the monitoring step, forming a loop logic. Only when the feedback value of the second humidity sensor 12 is lower than the set threshold does the system determine that the external pipeline is basically dry and the liquid has been recovered, and then proceeds to the next step. When the feedback value of the second humidity sensor 12 is lower than the set threshold, the system determines that there is no residual liquid in the external pipeline, completing the recovery of the residual circulating liquid in the circulation pipeline.

[0027] After completing the purging operation of the circulation pipeline, the purging operation of the internal pipeline begins. The internal pipeline is mainly located between the water tank and the refrigeration module. A water pump is installed on the internal pipeline. Two parallel one-way solenoid valves in opposite directions (i.e., the first solenoid valve 1 and the second solenoid valve 2) are installed between the water tank and the refrigeration module. The one-way solenoid valve from the refrigeration module to the water tank is also equipped with a first humidity sensor 11.

[0028] The first solenoid valve 1 opens during the purging operation of the internal pipeline, serving as a passage for the residual circulating fluid in the internal pipeline to return to the water tank. The second solenoid valve 2 opens as the circulating fluid circulation pipeline during normal operation of the cold water, and closes during the purging operation.

[0029] After the purging operation of the circulation pipeline is completed, first close the seventh solenoid valve 7, then close the second solenoid valve 2, the fourth solenoid valve 4, the fifth solenoid valve 5, and the eighth solenoid valve 8, while simultaneously opening the first solenoid valve 1 and the third solenoid valve 3. Subsequently, the seventh solenoid valve 7 is reopened, and compressed air circulates within the system, gradually purging the residual liquid in the chiller's internal pipeline through the pathway consisting of "connection point 13 -> third solenoid valve 3 -> refrigeration module -> first solenoid valve 1 -> water tank" to the water tank.

[0030] During the internal purging process, the first humidity sensor 11 monitors the dryness of the internal pipeline in real time. If the sensor feedback value is higher than the threshold, purging continues. If the feedback value of the first humidity sensor 11 is lower than the set threshold, the system determines that the internal pipeline is dry, and the program terminates: the control system issues a command to close all one-way solenoid valves (including the solenoid valve at the air source inlet), cut off the compressed air, and complete the recovery of the circulating liquid.

[0031] When the feedback value of the first humidity sensor 11 is lower than the set threshold, the system determines that the internal pipes are dry, and all solenoid valves close, thus completing the centralized collection of waste liquid in the chiller pipes. If the user no longer needs to use the equipment, they can manually open the hand valve to discharge the waste liquid collected in the water tank to a designated container. The ninth one-way valve 9 and the tenth one-way valve 10 are set in opposite directions. Their function is to balance the system air pressure during normal operation of the chiller, ensuring stable circulation.

[0032] Example 2: This example provides a chiller circulating fluid recovery system and method. The system includes a water tank, a refrigeration module, an external load interface, and a purging module. The core of this example lies in constructing two independent fluid recovery paths: one for the external load pipeline, i.e., the recovery of the circulating pipeline, and the other for the internal core components, i.e., the recovery of the internal pipeline.

[0033] like Figure 2 As shown, a logic network consisting of multiple one-way solenoid valves is installed on the circulation pipeline between the refrigeration module and the external load. Specifically, the dry compressed air pipeline is connected to the access point 13 of the circulation pipeline through a one-way solenoid valve; between the refrigeration module and the access point 13 of the circulation pipeline, two one-way solenoid valves with opposite directions (i.e., the third solenoid valve 3 and the fourth solenoid valve 4) are connected in parallel. The cooperation of these two valves can control the flow direction of the fluid between the refrigeration module and the water tank during the purging operation.

[0034] Between the connection point 13 of the circulation pipeline and the external load, there is a one-way solenoid valve (i.e., the fifth solenoid valve 5) that leads from the connection point 13 to the external load; and on the return pipeline that leads from the external load to the water tank, there is a one-way solenoid valve (i.e., the eighth solenoid valve 8) that leads from the external load to the water tank, and a second humidity sensor 12 is located nearby.

[0035] When circulating liquid recovery from the chiller is required, the chiller must first be shut down. After the chiller is shut down, the user can initiate the waste liquid recovery program via the control panel. First, solenoid valves 1, 2, 3, and 4 close, while solenoid valves 5 and 8 open. Then, solenoid valve 7 opens, and the purging module begins its purging operation, with external dry compressed air entering the circulation loop through the pipeline. During this process, check valve 6 allows only unidirectional fluid flow, effectively preventing backflow of residual liquid in the pipeline. Driven by the compressed air, the residual waste liquid in the external pipeline is gradually purged into the water tank via the pathway consisting of "connection point 13 -> fifth solenoid valve 5 -> external load -> eighth solenoid valve 8 -> water tank".

[0036] During the purging process, the system does not blindly perform fixed-time purging. Instead, it monitors the humidity (or residual liquid) of the discharged gas in real time using the second humidity sensor 12. If the feedback value of the second humidity sensor 12 is higher than the set threshold, it indicates that there is still a large amount of liquid residue in the external pipeline. The control system maintains the current valve state, continues purging, and returns to the monitoring step, forming a loop logic. Only when the feedback value of the second humidity sensor 12 is lower than the set threshold does the system determine that the external pipeline is basically dry and the liquid has been recovered, and then proceeds to the next step. When the feedback value of the second humidity sensor 12 is lower than the set threshold, the system determines that there is no residual liquid in the external pipeline, completing the recovery of the residual circulating liquid in the circulation pipeline.

[0037] After completing the purging operation of the circulation pipeline, the purging operation of the internal pipeline begins. The internal pipeline is mainly located between the water tank and the refrigeration module. A water pump is installed on the internal pipeline. Two parallel one-way solenoid valves in opposite directions (i.e., the first solenoid valve 1 and the second solenoid valve 2) are installed between the water tank and the refrigeration module. The one-way solenoid valve from the refrigeration module to the water tank is also equipped with a first humidity sensor 11.

[0038] The first solenoid valve 1 opens during the purging operation of the internal pipeline, serving as a passage for the residual circulating fluid in the internal pipeline to return to the water tank. The second solenoid valve 2 serves as the circulating fluid circulation pipeline during normal operation of the cold water system and closes during the purging operation.

[0039] After the purging operation of the circulation pipeline is completed, first close the seventh solenoid valve 7, then close the second solenoid valve 2, the fourth solenoid valve 4, the fifth solenoid valve 5, and the eighth solenoid valve 8, while simultaneously opening the first solenoid valve 1 and the third solenoid valve 3. Subsequently, the seventh solenoid valve 7 is reopened, and compressed air circulates within the system, gradually purging the residual liquid in the chiller's internal pipeline through the pathway consisting of "connection point 13 -> third solenoid valve 3 -> refrigeration module -> first solenoid valve 1 -> water tank" to the water tank.

[0040] During the internal purging process, the first humidity sensor 11 monitors the dryness of the internal pipeline in real time. If the sensor feedback value is higher than the threshold, purging continues. If the feedback value of the first humidity sensor 11 is lower than the set threshold, the system determines that the internal pipeline is dry, and the program terminates: the control system issues a command to close all one-way solenoid valves (including the solenoid valve at the air source inlet), cut off the compressed air, and complete the recovery of the circulating liquid.

[0041] When the feedback value of the first humidity sensor 11 is lower than the set threshold, the system determines that the internal pipes are dry, and all solenoid valves close, thus completing the centralized collection of waste liquid in the chiller pipes. If the user no longer needs to use the equipment, they can manually open the hand valve to discharge the waste liquid collected in the water tank to a designated container. The ninth one-way valve 9 and the tenth one-way valve 10 are set in opposite directions. Their function is to balance the system air pressure during normal operation of the chiller, ensuring stable circulation.

[0042] During normal operation of the chiller, only the one-way solenoid valves (i.e., solenoid valve 2, solenoid valve 4, solenoid valve 5, and solenoid valve 8) on the four main flow paths—from the water tank to the refrigeration module, from the refrigeration module to access point 13, from access point 13 to the external load, and from the external load to the water tank—are opened. All other valves used for purging and recovery (such as valves connecting to the air source) remain closed. During this period, the two one-way valves (nine one-way valve 9 and tenth one-way valve 10) on the top of the water tank are in operation. Based on minor fluctuations in the internal air pressure of the water tank, they automatically perform small-scale venting or replenishment of air to achieve dynamic balance, ensuring stable pump head and system sealing.

[0043] Through the detailed description of the above embodiments, the technical effects of the present invention are fully realized: High degree of automation: Users only need to start the "waste liquid recovery program" on the control panel, and the system can automatically complete valve switching, purging, detection and shutdown without manual disassembly of pipelines, completely eliminating the risk of human error.

[0044] Thorough recovery: The phased purging strategy of "outside first, then inside" is adopted, combined with the dual feedback of the first and second humidity sensors, to ensure that the liquid from the external load to the internal core components is completely recovered, with an extremely high recovery rate.

[0045] Economy and safety: It effectively avoids the leakage and volatilization of expensive electronic fluorinated liquids, which not only saves on operation and maintenance costs, but also prevents false alarms of sensors and production interruptions caused by volatile gases, ensuring the continuous operation of precision production lines such as semiconductors.

[0046] Example 3: A chiller circulating liquid recovery system includes a water tank and a refrigeration module connected by internal pipelines. The water tank and the refrigeration module are also connected to an external load through a circulation pipeline. A purging module is provided on the circulation pipeline from the refrigeration module to the external load. The purging module includes several one-way solenoid valves and a dry compressed air pipeline.

[0047] This embodiment also provides a method for recovering circulating liquid from a chiller, applied to the aforementioned chiller circulating liquid recovery system, comprising the following steps: S1. Turn off the chiller, open the three one-way solenoid valves that connect the dry compressed air pipeline to the access point 13, the access point 13 to the external load, and the external load to the water tank, close the other one-way solenoid valves, start the purging module to purge the circulation pipeline, and purge the residual liquid in the circulation pipeline to the water tank. S2. Connect the dry compressed air pipeline to access point 13, access point 13 to the refrigeration module, open the one-way solenoid valve of the refrigeration module to the water tank, close the other one-way solenoid valves, start the purging module to purge the internal pipeline, and purge the residual liquid in the internal pipeline to the water tank.

[0048] like Figure 2 As shown, a logic network consisting of multiple one-way solenoid valves is installed on the circulation pipeline between the refrigeration module and the external load. Specifically, the dry compressed air pipeline is connected to the access point 13 of the circulation pipeline through a one-way solenoid valve; between the refrigeration module and the access point 13 of the circulation pipeline, two one-way solenoid valves with opposite directions (i.e., the third solenoid valve 3 and the fourth solenoid valve 4) are connected in parallel. The cooperation of these two valves can control the flow direction of the fluid between the refrigeration module and the water tank during the purging operation.

[0049] Between the connection point 13 of the circulation pipeline and the external load, there is a one-way solenoid valve (i.e., the fifth solenoid valve 5) that leads from the connection point 13 to the external load; and on the return pipeline that leads from the external load to the water tank, there is a one-way solenoid valve (i.e., the eighth solenoid valve 8) that leads from the external load to the water tank, and a second humidity sensor 12 is located nearby.

[0050] The core of this embodiment lies in constructing two independent fluid recovery paths: one for external load pipelines, i.e., the recovery of the circulation pipeline, and the other for internal core components, i.e., the recovery of the internal pipeline.

[0051] The external load circulation path consists of the following one-way solenoid valves connected in series: the one-way solenoid valve connecting the refrigeration module to connection point 13 (i.e., the fourth solenoid valve 4), the one-way solenoid valve connecting connection point 13 to the external load (i.e., the fifth solenoid valve 5), and the one-way solenoid valve connecting the external load to the water tank (i.e., the eighth solenoid valve 8). This path is used to transport refrigerant during normal operation and serves as the main waste liquid discharge channel during the recovery phase.

[0052] The internal core circulation path consists of a one-way solenoid valve (i.e., the second solenoid valve 2) connecting the water tank to the refrigeration module, a one-way solenoid valve (i.e., the first solenoid valve 1) connecting the refrigeration module to the water tank, and a one-way solenoid valve (i.e., the third solenoid valve 3) connecting the access point 13 to the refrigeration module. The first solenoid valve 1 and the second solenoid valve 2 are physically connected in parallel to change the fluid flow direction during the switching between purging and normal operation.

[0053] In this embodiment, the system uses dry compressed air as a power source. During the purging process, the dry compressed air is input to access point 13 through a one-way solenoid valve (i.e., the seventh solenoid valve 7). In terms of control logic, the system has a first feedback node (corresponding to the refrigeration module circuit) and a second feedback node (corresponding to the external load circuit), which are respectively connected to the first and second humidity sensors to send humidity signals to the controller.

[0054] During normal cooling operation of the chiller, solenoid valves 2, 4, 5, and 8 are open, forming a closed loop of "water tank -> refrigeration module -> connection point 13 -> external load -> water tank". Other one-way solenoid valves are closed to ensure that compressed air does not enter the circulation system. The two one-way valves on the top of the water tank automatically regulate the system pressure to ensure stable operation of the circulation pump.

[0055] Upon receiving a shutdown and recovery command, the system enters the second state to recover residual circulating liquid from the external load circulation path. At this time, the seventh solenoid valve 7, the fifth solenoid valve 5, and the eighth solenoid valve 8 are open, while other one-way solenoid valves are closed. Dry compressed air enters through the solenoid valves, flows to the access point 13 via the seventh solenoid valve 7, and then flows to the external load via the fifth solenoid valve 5. At this point, the residual liquid in the external load, driven by air pressure, cannot flow back to the closed refrigeration module and can only flow out through the eighth solenoid valve 8, ultimately being forced into the water tank. During this process, the second humidity sensor 12 continuously monitors the gas humidity at the external load outlet, i.e., at the eighth solenoid valve 8. If the detected humidity value is higher than the preset drying threshold, the controller maintains the current valve state and continues purging; if the humidity value drops below the threshold, the controller determines that the external circulation pipeline recovery is complete and enters the next stage.

[0056] After the external pipeline recovery is complete, the system enters the third state to handle the residual liquid inside the refrigeration module. At this time, valve reconfiguration is performed, closing the second solenoid valve 2, the fourth solenoid valve 4, the fifth solenoid valve 5, and the eighth solenoid valve 8 (cutting off the external pipeline), while simultaneously opening the first solenoid valve 1 and the third solenoid valve 3 (refrigeration module water return). Compressed air enters through the seventh solenoid valve 77 and is input into the refrigeration module through the third solenoid valve 3. Since the external pipeline has been cut off, the airflow can only push the residual liquid inside the refrigeration module back to the water tank through the first solenoid valve 1. During this process, the first humidity sensor 11 monitors the humidity at the first solenoid valve 1. When the value fed back by the first humidity sensor 11 is lower than the set threshold, it indicates that the inside of the refrigeration module is dry and there is no residual liquid, signifying that the recovery of residual circulating liquid from all external and internal pipelines has been completed.

[0057] The technical solution of this embodiment utilizes multi-valve logic control and a staged purging strategy integrated within the chiller to automatically recover residual electronic fluorinated liquid in both external and internal pipelines after shutdown, eliminating the need for manual pipe disassembly and significantly reducing the loss of expensive circulating fluid and labor maintenance costs. Combined with closed-loop feedback from a humidity sensor, the purging duration is precisely controlled, avoiding compressed air waste; the bidirectional pressure balance structure ensures the stability of normal equipment operation. This overall solution fundamentally avoids the risk of sensor false alarms and production interruptions caused by liquid leakage, demonstrating outstanding practical value in improving operational convenience, economy, and operational reliability.

Claims

1. A chiller circulating liquid recovery system, characterized in that, It includes a water tank and a refrigeration module connected by internal piping. The water tank and the refrigeration module are also connected to an external load through a circulation pipeline. A purging module is installed on the circulation pipeline from the refrigeration module to the external load. The purging module includes several one-way solenoid valves and a dry compressed air pipeline.

2. The chiller circulating liquid recovery system according to claim 1, characterized in that, The dry compressed air pipeline is connected to the connection point of the circulation pipeline through a one-way solenoid valve; two one-way solenoid valves in opposite directions are connected in parallel between the refrigeration module and the connection point of the circulation pipeline; a one-way solenoid valve connecting the connection point of the circulation pipeline to the external load is provided between the connection point of the circulation pipeline and the external load.

3. The chiller circulating liquid recovery system according to claim 1, characterized in that, An internal pipeline is equipped with a water pump, and two parallel one-way solenoid valves in opposite directions are connected between the water tank and the refrigeration module. The one-way solenoid valve from the refrigeration module to the water tank is also equipped with a first humidity sensor.

4. The chiller circulating liquid recovery system according to claim 1, characterized in that, The water tank is equipped with two one-way valves in opposite directions to balance the air pressure of the system.

5. The chiller circulating liquid recovery system according to claim 1, characterized in that, A second humidity sensor and a one-way solenoid valve are installed on the circulation pipeline between the external load and the water tank.

6. A method for recovering circulating fluid from a chiller, applied to the chiller circulating fluid recovery system according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Turn off the chiller, open the three one-way solenoid valves that connect the dry compressed air pipeline to the access point, the access point to the external load, and the external load to the water tank, close the other one-way solenoid valves, start the purging module to purge the circulation pipeline, and purge the residual liquid in the circulation pipeline to the water tank. S2. Connect the dry compressed air pipeline to the access point, the access point to the refrigeration module, and the one-way solenoid valve connecting the refrigeration module to the water tank. Close the other one-way solenoid valves and start the purging module to purge the internal pipeline and purge the residual liquid in the internal pipeline to the water tank.

7. The chiller circulating liquid recovery method according to claim 6, characterized in that, During the continuous purging process of the purging module in S1, the second humidity sensor determines whether the pipeline is dry. When the feedback value of the second humidity sensor is lower than the set threshold, step S2 is executed.

8. The chiller circulating liquid recovery method according to claim 6 or 7, characterized in that, During the continuous purging process of the S2 purging module, the first humidity sensor determines whether the pipeline is dry. When the feedback value from the second humidity sensor is lower than the set threshold, the purging work of recycling the circulating liquid is completed.

9. The chiller circulating liquid recovery method according to claim 6, characterized in that, During normal operation of the chiller, only four one-way solenoid valves are opened: one connecting the water tank to the refrigeration module, one connecting the refrigeration module to the connection point, one connecting the connection point to the external load, and one connecting the external load to the water tank. All other one-way solenoid valves are closed.

10. The chiller circulating liquid recovery method according to claim 9, characterized in that, During normal operation of the chiller, the system air pressure is dynamically balanced through two one-way valves with opposite directions installed on the water tank.

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