Battery thermal management test system and refrigerant recovery method

Abstract

This invention relates to the field of battery thermal management testing technology, and discloses a battery thermal management testing system and a refrigerant recovery method. This battery thermal management testing system can switch between battery testing mode and refrigerant recovery mode via valve switching. During refrigerant recovery, it relies on its own compressor, gas-liquid separator, and liquid storage tank to assist in refrigerant recovery. The refrigerant recovery machine recovers refrigerant by connecting to the liquid storage tank and gas-liquid separator. By detecting the refrigerant temperature in the battery, gas-liquid separator, and liquid storage tank, it determines whether heating is needed to facilitate refrigerant extraction by the compressor, precisely controlling the start point of recovery. Similarly, by detecting the refrigerant pressure in the battery and refrigeration circuit, it precisely controls the end point of recovery, improving refrigerant recovery efficiency while ensuring complete refrigerant recovery. Heaters are connected to both the gas-liquid separator and the liquid storage tank to heat and evaporate residual refrigerant in these components, solving the problem of refrigerant residue caused by dead zones in the system.

Description

Technical Field

[0001] This invention relates to the field of battery thermal management testing technology, and in particular to a battery thermal management testing system and a refrigerant recovery method. Background Technology

[0002] Battery testing equipment utilizes refrigerant phase change refrigeration technology, which leverages the principle of refrigerant absorbing or releasing heat during phase change to directly cool or heat the battery, meeting testing requirements under various operating conditions. This technology eliminates the need for secondary heat exchange, offering high heat exchange efficiency, a wide temperature range, and simple equipment structure. It is suitable for testing hybrid battery packs, pure electric battery packs, and batteries compatible with both pure electric and hybrid systems. After testing, the refrigerant in the refrigeration system and / or battery pack needs to be recovered.

[0003] Under low-temperature testing conditions, the refrigerant inside the battery pack is in a low-temperature, low-pressure liquid state, with its saturated vapor pressure far below that of room temperature. Firstly, conventional refrigerant recovery machines rely on the pressure difference generated by the compressor after the refrigerant evaporates into a gaseous state. However, liquid refrigerant has poor fluidity and is difficult to effectively extract through the recovery machine's piping, resulting in poor recovery and potential refrigerant leakage into the environment when the piping is disconnected after recovery. Secondly, the refrigeration system in battery testing includes multiple components connected by pipes. Dead zones can easily form at these connection points, valve cores, and the bottom of the liquid storage tank, leaving refrigerant residue. Consequently, conventional refrigerant recovery machines suffer from long recovery times, incomplete recovery, and low efficiency.

[0004] Therefore, there is an urgent need for a battery thermal management testing system and a refrigerant recovery method to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a battery thermal management testing system and refrigerant recovery method with high refrigerant recovery efficiency and complete recovery capability.

[0006] To achieve this objective, the present invention adopts the following technical solution: A battery thermal management testing system includes a refrigeration circuit and a refrigerant recovery unit. The refrigeration circuit includes a gas-liquid separator, a compressor, and a refrigerant tank connected in sequence. A first on / off valve is connected between the battery inlet and the outlet of the refrigerant tank, and a second on / off valve is connected between the battery outlet and the inlet of the gas-liquid separator. The battery thermal management testing system further includes a temperature measuring mechanism and a pressure measuring mechanism. The temperature measuring mechanism is used to detect the refrigerant temperature in the battery, the gas-liquid separator, and the liquid storage tank, respectively. The pressure measuring mechanism is used to detect the refrigerant pressure in the battery and the refrigeration circuit, respectively. Heaters are connected to both the gas-liquid separator and the liquid storage tank. The refrigerant recovery port of the refrigerant recovery machine can be simultaneously connected to or disconnected from the liquid storage tank and the gas-liquid separator.

[0007] Preferably, the temperature measuring mechanism includes a first temperature measuring element and a second temperature measuring element. The first temperature measuring element is connected to the inlet pipe of the battery and is used to measure the refrigerant temperature at the inlet of the battery. The second temperature measuring element is connected to the outlet pipe of the battery and is used to measure the refrigerant temperature at the outlet of the battery. And / or, the pressure measuring mechanism includes a first pressure measuring element and a second pressure measuring element, the first pressure measuring element being connected to the inlet pipe of the battery for measuring the pressure value at the inlet of the battery, and the second pressure measuring element being connected to the outlet pipe of the battery for measuring the pressure value at the outlet of the battery.

[0008] Preferably, the temperature measuring mechanism further includes a third temperature measuring element and a fourth temperature measuring element, wherein the third temperature measuring element is connected to the gas-liquid separator and the fourth temperature measuring element is connected to the liquid storage tank.

[0009] Preferably, the pressure measuring mechanism further includes a third pressure measuring element, and the refrigeration circuit further includes a first throttle valve, which is located between the liquid storage tank and the first on / off valve. The third pressure measuring element is disposed on the refrigeration circuit and connected to the pipeline between the liquid storage tank and the first throttle valve.

[0010] Preferably, a first control valve is connected between the refrigerant recovery port of the refrigerant recovery machine and the liquid storage tank, and a second control valve is connected between the refrigerant recovery port of the refrigerant recovery machine and the gas-liquid separator.

[0011] A refrigerant recovery method, applied to the aforementioned battery thermal management test system, includes the following steps: S100: The temperature measuring mechanism detects the refrigerant temperature inside the battery and determines whether the refrigerant temperature inside the battery is lower than the first preset temperature; if the refrigerant temperature inside the battery is lower than the first preset temperature, then step S200 is executed; if the refrigerant temperature inside the battery is higher than or equal to the first preset temperature, then step S300 is executed. S200: Heat the battery until the temperature of the refrigerant inside the battery reaches the first preset temperature, then stop heating. S300: Close the first on / off valve and open the second on / off valve to start the compressor; S400: The pressure measuring mechanism monitors the refrigerant pressure in the battery in real time until the refrigerant pressure in the battery is lower than the first preset pressure, then closes the second on / off valve. S500: Connect the refrigerant recovery port of the refrigerant recovery machine to the liquid storage tank and the gas-liquid separator simultaneously, and turn on the refrigerant recovery machine; at the same time, the temperature measuring mechanism detects the refrigerant temperature in the liquid storage tank and the gas-liquid separator respectively, and determines whether the refrigerant temperature in the liquid storage tank and / or the gas-liquid separator is lower than the second preset temperature; if the refrigerant temperature of at least one of the liquid storage tank and the gas-liquid separator is lower than the second preset temperature, proceed to step S600; if the refrigerant temperature in both the liquid storage tank and the gas-liquid separator is higher than or equal to the second preset temperature, proceed to step S700. S600, turn on the heater on the liquid storage tank and / or the gas-liquid separator until the refrigerant temperature in the liquid storage tank and the gas-liquid separator reaches the second preset temperature; S700, the pressure measuring mechanism detects the refrigerant pressure in the refrigeration circuit in real time until the refrigerant pressure in the refrigeration circuit is lower than the second preset pressure, and then shuts down the refrigerant recovery machine.

[0012] Preferably, the temperature measuring mechanism includes a first temperature measuring element and a second temperature measuring element, wherein the first temperature measuring element is connected to the inlet pipe of the battery and the second temperature measuring element is connected to the outlet pipe of the battery. In step S100, the temperature values ​​measured by the first temperature measuring element and the second temperature measuring element are obtained, and the average value of the temperature values ​​measured by the first temperature measuring element and the second temperature measuring element is calculated to obtain the refrigerant temperature inside the battery.

[0013] Preferably, in step S200, the battery is heated by opening the first on / off valve and the second on / off valve and starting the compressor. When the refrigerant temperature inside the battery reaches the first preset temperature, the compressor is turned off.

[0014] Preferably, the pressure measuring mechanism includes a first pressure measuring element and a second pressure measuring element, wherein the first pressure measuring element is connected to the inlet pipe of the battery, and the second pressure measuring element is connected to the outlet pipe of the battery. In step S400, the pressure values ​​measured by the first pressure measuring device and the second pressure measuring device are obtained, and the average value of the pressure values ​​measured by the first pressure measuring device and the second pressure measuring device is calculated to obtain the refrigerant pressure in the battery.

[0015] Preferably, a first control valve is connected between the refrigerant recovery port of the refrigerant recovery machine and the liquid storage tank, and a second control valve is connected between the refrigerant recovery port of the refrigerant recovery machine and the gas-liquid separator. In step S500, the refrigerant recovery port of the refrigerant recovery machine is simultaneously connected to the liquid storage tank and the gas-liquid separator by opening the first control valve and the second control valve.

[0016] The beneficial effects of this invention are: This invention proposes a battery thermal management testing system, including a refrigeration circuit and a refrigerant recovery machine. The refrigeration circuit includes a gas-liquid separator, a compressor, and a liquid storage tank connected in sequence. A first on / off valve is connected between the battery inlet and the liquid storage tank outlet, and a second on / off valve is connected between the battery outlet and the gas-liquid separator inlet. The battery thermal management testing system also includes a temperature measuring mechanism and a pressure measuring mechanism. The temperature measuring mechanism is used to detect the refrigerant temperature in the battery, the gas-liquid separator, and the liquid storage tank, respectively, and the pressure measuring mechanism is used to detect the refrigerant pressure in the battery and the refrigeration circuit, respectively. Heaters are connected to both the gas-liquid separator and the liquid storage tank. The recovery port of the refrigerant recovery machine can be simultaneously connected to or disconnected from the liquid storage tank and the gas-liquid separator. This battery thermal management testing system can switch between battery testing mode and refrigerant recovery mode via valve switching. During the refrigerant recovery process, it relies on its own compressor, gas-liquid separator, and liquid storage tank to assist in refrigerant recovery. The refrigerant recovery machine recovers refrigerant by connecting to the liquid storage tank and gas-liquid separator. Moreover, a temperature measuring device detects the refrigerant temperature in the battery, gas-liquid separator, and liquid storage tank to determine whether heating is needed to facilitate refrigerant extraction by the compressor and precisely control the start point of the recovery process. A pressure measuring device detects the refrigerant pressure in the battery and refrigeration circuit to precisely control the end point of the recovery process, improving refrigerant recovery efficiency while ensuring complete refrigerant recovery. In addition, heaters are connected to the gas-liquid separator and liquid storage tank to heat and evaporate residual refrigerant in these components, solving the problem of refrigerant residue caused by dead zones in the system.

[0017] On the other hand, the present invention also proposes a refrigerant recovery method, applied to the aforementioned battery thermal management test system. The refrigerant recovery method includes: S100, a temperature measuring mechanism detects the refrigerant temperature inside the battery and determines whether the refrigerant temperature inside the battery is lower than a first preset temperature; if the refrigerant temperature inside the battery is lower than the first preset temperature, proceed to step S200; if the refrigerant temperature inside the battery is higher than or equal to the first preset temperature, proceed to step S300; S200, the battery is heated until the refrigerant temperature inside the battery reaches the first preset temperature, and then the heating is stopped; S300, the first on / off valve is closed and the second on / off valve is opened, and the compressor is started; S400, a pressure measuring mechanism monitors the refrigerant pressure inside the battery in real time until the refrigerant pressure inside the battery is lower than the first preset pressure. Close the second shut-off valve; S500, connect the refrigerant recovery port of the refrigerant recovery machine to the liquid storage tank and the gas-liquid separator simultaneously, and turn on the refrigerant recovery machine; at the same time, the temperature measuring mechanism detects the refrigerant temperature in the liquid storage tank and the gas-liquid separator respectively. If the refrigerant temperature in at least one of the liquid storage tank and the gas-liquid separator is lower than the second preset temperature, proceed to step S600. If the refrigerant temperature in both the liquid storage tank and the gas-liquid separator is higher than the second preset temperature, proceed to step S700; S600, turn on the heater on the liquid storage tank and / or the gas-liquid separator until the temperature of both the liquid storage tank and the gas-liquid separator reaches the second preset temperature; S700, the pressure measuring mechanism detects the refrigerant pressure in the refrigeration circuit in real time until the refrigerant pressure in the refrigeration circuit is lower than the second preset pressure, and then turn off the refrigerant recovery machine. This refrigerant recovery method first recovers the refrigerant inside the battery, and then recovers the refrigerant from the entire refrigeration circuit. It can process the refrigerant in the system in batches, realizing the recovery of refrigerant in the entire battery thermal management test system, and avoiding the inefficiency of one-time recovery. Moreover, during the recovery process, the pressure of the refrigerant in the battery and refrigeration circuit is monitored in real time by the pressure measuring mechanism, and combined with the temperature parameters measured by the temperature measuring mechanism, the start and end points of the recovery process can be precisely controlled to ensure thorough refrigerant recovery and eliminate the problem of refrigerant residue caused by dead zones in the system. Attached Figure Description

[0018] Figure 1 This is a connection diagram of the battery thermal management test system proposed in this embodiment of the present invention; Figure 2 This is a schematic flowchart of the refrigerant recovery method proposed in this embodiment of the present invention.

[0019] In the picture: 1. Refrigeration circuit; 11. Second throttle valve; 12. Second heat exchanger; 13. Gas-liquid separator; 14. Compressor; 15. Condenser; 16. Liquid receiver; 17. First heat exchanger; 18. First throttle valve; 2. First on / off valve; 3. Second shut-off valve; 41. First temperature measuring element; 42. Second temperature measuring element; 43. Third temperature measuring element; 44. Fourth temperature measuring element; 45. Fifth temperature measuring element; 51. First pressure measuring element; 52. Second pressure measuring element; 53. Third pressure measuring element; 6. Heater; 7. First control valve; 8. Second control valve; 100. Battery. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0021] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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 limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0024] Reference Figure 1This embodiment proposes a battery thermal management testing system, including a refrigeration circuit 1 and a refrigerant recovery machine (not shown in the figure). The refrigeration circuit 1 includes a gas-liquid separator 13, a compressor 14, and a liquid storage tank 16 connected in sequence. A first on-off valve 2 is connected between the inlet of the battery 100 and the outlet of the liquid storage tank 16, and a second on-off valve 3 is connected between the outlet of the battery 100 and the inlet of the gas-liquid separator 13. The battery thermal management testing system also includes a temperature measuring mechanism and a pressure measuring mechanism. The temperature measuring mechanism is used to detect the refrigerant temperature in the battery 100, the gas-liquid separator 13, and the liquid storage tank 16, respectively. The pressure measuring mechanism is used to detect the refrigerant pressure in the battery 100 and the refrigeration circuit 1, respectively. Heaters 6 are connected to both the gas-liquid separator 13 and the liquid storage tank 16. The recovery port of the refrigerant recovery machine can be simultaneously connected to or disconnected from the liquid storage tank 16 and the gas-liquid separator 13.

[0025] This battery thermal management testing system integrates a refrigeration circuit 1 and a refrigerant recovery unit. Through on / off valves and piping connections, it achieves seamless switching between testing and refrigerant recovery, simplifying the operation process. During refrigerant recovery, the system utilizes its own compressor 14, gas-liquid separator 13, and liquid storage tank 16 to assist in refrigerant recovery. Finally, the refrigerant recovery unit, connected to the liquid storage tank 16 and gas-liquid separator 13, achieves refrigerant recovery, significantly improving recovery efficiency. In addition, the temperature of the refrigerant in the battery 100, gas-liquid separator 13 and liquid storage tank 16 is detected by the temperature measuring mechanism to determine whether heating is required so that the compressor 14 can extract the refrigerant and precisely control the start point of the recovery process. The pressure measuring mechanism detects the refrigerant pressure in the battery 100 and refrigeration circuit 1 to precisely control the end point of the recovery process, thereby improving the refrigerant recovery efficiency and ensuring that the refrigerant is completely recovered. In addition, heaters 6 are connected to both the gas-liquid separator 13 and the liquid storage tank 16, which can heat and evaporate the residual refrigerant in these components to solve the problem of refrigerant residue caused by dead zones in the system.

[0026] Specifically, the refrigeration circuit 1 includes, in sequence, a second on-off valve 3, a second throttle valve 11, a second heat exchanger 12, a gas-liquid separator 13, a compressor 14, a condenser 15, a liquid receiver 16, a first heat exchanger 17, a first throttle valve 18, and a first on-off valve 2, connected end-to-end. The outlet of the first on-off valve 2 is connected to the inlet of the battery 100, and the inlet of the second on-off valve 3 is connected to the outlet of the battery 100. It can be understood that "end-to-end" means that the outlet of one component is connected to the inlet of the next component. Furthermore, in the refrigeration circuit 1, every two adjacent components can be connected via pipes or directly. Optionally, both the first heat exchanger 17 and the second heat exchanger 12 are plate heat exchangers. The condenser 15 condenses and releases heat through an internal condenser fan, and during the refrigerant recovery process, the condenser fan of the condenser 15 can be in a closed state.

[0027] Optionally, the first on-off valve 2 and the second on-off valve 3 can be one or more of the following shut-off valves: gate valve, globe valve, or ball valve. The first on-off valve 2 and the second on-off valve 3 can be of the same or different types. In this embodiment, both the first on-off valve 2 and the second on-off valve 3 are gate valves.

[0028] The gas-liquid separator 13 separates gaseous and liquid refrigerant to ensure that only gaseous refrigerant enters the compressor 14. Connecting the gas-liquid separator 13 to the inlet side of the compressor 14 can prevent liquid refrigerant from directly entering the compressor 14 and causing liquid slugging damage. The liquid storage tank 16 stores the liquid refrigerant condensed by the condenser 15. Therefore, the refrigerant storage in the gas-liquid separator 13 and the liquid storage tank 16 is relatively large. Connecting the refrigerant recovery port of the refrigerant recovery machine to the liquid storage tank 16 and the gas-liquid separator 13 at the same time can improve the efficiency and speed of refrigerant recovery.

[0029] In the battery thermal management testing system, the cooling process of the refrigerant on the battery 100 mainly occurs inside the cold plate within the battery 100. The cold plate is in close contact with the battery 100 module. Therefore, in some embodiments, when measuring the temperature of the refrigerant inside the battery 100, the temperature of the cold plate can be directly measured. Specifically, the temperature measuring mechanism may include a temperature sensor disposed on a flow channel inside the cold plate, which measures the temperature of the refrigerant inside the battery 100. The pressure measuring mechanism may include a pressure sensor disposed on a flow channel inside the cold plate, which measures the pressure of the refrigerant inside the battery 100.

[0030] In this embodiment, the temperature measuring mechanism includes a first temperature measuring element 41 and a second temperature measuring element 42. The first temperature measuring element 41 is connected to the inlet pipe of the battery 100 and is used to measure the refrigerant temperature at the inlet of the battery 100. The second temperature measuring element 42 is connected to the outlet pipe of the battery 100 and is used to measure the refrigerant temperature at the outlet of the battery 100. In the closed battery thermal management test system, the refrigerant flows continuously, and the parameters of the inlet and outlet of the battery 100 can reflect the average state inside the battery 100. Therefore, the first temperature measuring element 41 is set at the inlet of the battery 100 to measure the refrigerant temperature at the inlet of the battery 100, and the second temperature measuring element 42 is set at the outlet of the battery 100 to measure the refrigerant temperature at the outlet of the battery 100. The average value of the inlet temperature and the outlet temperature can reflect the overall temperature of the refrigerant inside the battery 100, thereby providing a recovery start point when recovering the internal refrigerant of the battery 100. Similarly, the pressure measuring mechanism includes a first pressure measuring element 51 and a second pressure measuring element 52. The first pressure measuring element 51 is connected to the inlet pipe of the battery 100 and is used to measure the pressure value at the inlet of the battery 100. The second pressure measuring element 52 is connected to the outlet pipe of the battery 100 and is used to measure the pressure value at the outlet of the battery 100. The first pressure measuring element 51 is installed at the inlet of the battery 100 to measure the pressure at the inlet, and the second pressure measuring element 52 is installed at the outlet of the battery 100 to measure the pressure at the outlet. The average of the inlet pressure value and the outlet pressure value reflects the overall refrigerant pressure inside the battery 100, thus providing a recovery termination point during subsequent refrigerant recovery from the battery 100.

[0031] Optionally, the first temperature measuring element 41 and / or the second temperature measuring element 42 may be NTC thermistors; the first pressure measuring element 51 and / or the second pressure measuring element 52 may be piezoelectric pressure sensors.

[0032] Furthermore, the temperature measuring mechanism also includes a third temperature measuring element 43 and a fourth temperature measuring element 44. The third temperature measuring element 43 is connected to the gas-liquid separator 13, and the fourth temperature measuring element 44 is connected to the liquid storage tank 16. The third temperature measuring element 43 is disposed on the outer wall of the gas-liquid separator 13 to detect the internal refrigerant temperature of the gas-liquid separator 13, and the fourth temperature measuring element 44 is disposed on the outer wall of the liquid storage tank 16 to detect the internal refrigerant temperature of the liquid storage tank 16, thereby providing a recovery start point when recovering the refrigerant in the gas-liquid separator 13 and the liquid storage tank 16.

[0033] Furthermore, the pressure measuring mechanism also includes a third pressure measuring element 53, and the refrigeration circuit 1 also includes a first throttle valve 18, which is located between the liquid storage tank 16 and the first on / off valve 2. The third pressure measuring element 53 is disposed on the refrigeration circuit 1 and connected to the pipeline between the liquid storage tank 16 and the first throttle valve 18. The third pressure measuring element 53 is used to measure the refrigerant pressure in the refrigeration circuit 1, thereby providing a recovery termination point when recovering the refrigerant in the gas-liquid separator 13 and the liquid storage tank 16. In addition, the temperature measuring mechanism may also include a fifth temperature measuring element 45, which is disposed on the refrigeration circuit 1 and connected to the pipeline between the liquid storage tank 16 and the first on / off valve 2, for measuring the temperature of the refrigeration circuit 1, thereby improving operational safety.

[0034] Furthermore, a first control valve 7 is connected between the refrigerant recovery port of the refrigerant recovery machine and the liquid storage tank 16, and a second control valve 8 is connected between the refrigerant recovery port of the refrigerant recovery machine and the gas-liquid separator 13. The control valves installed on the recovery pipelines of the liquid storage tank 16 and the gas-liquid separator 13 provide precise safety protection for the pressure characteristics of different components and improve operational safety. Additionally, during refrigeration, the first control valve 7 and the second control valve 8 can also be connected to the refrigerant charging port. Optionally, the first control valve 7 and the second control valve 8 can be one or more safety protection valves, such as safety valves or relief valves, and the types of the first control valve 7 and the second control valve 8 can be the same or different. In this embodiment, both the first control valve 7 and the second control valve 8 are safety valves.

[0035] On the other hand, refer to Figure 2 This embodiment also proposes a refrigerant recovery method, applied to the above-mentioned battery thermal management test system. The refrigerant recovery method includes: S100: The temperature measuring mechanism detects the refrigerant temperature inside the battery 100 and determines whether the refrigerant temperature inside the battery 100 is lower than the first preset temperature; if the refrigerant temperature inside the battery 100 is lower than the first preset temperature, proceed to step S200; if the refrigerant temperature inside the battery 100 is higher than or equal to the first preset temperature, proceed to step S300.

[0036] In the refrigerant recovery method proposed in this embodiment, the refrigerant inside the battery 100 needs to be recovered first. Before recovery, the temperature of the refrigerant inside the battery 100 is detected to determine the state of the internal refrigerant. If the temperature of the refrigerant inside the battery 100 is lower than the first preset temperature, it indicates that there is a large amount of low-temperature, low-pressure liquid refrigerant inside the battery 100. This refrigerant is then heated up, i.e., proceeding to step S200. If the temperature of the refrigerant inside the battery 100 is higher than or equal to the first preset temperature, the heating process in step S200 can be skipped and the process can proceed directly to step S300.

[0037] S200: Heat up the battery 100 until the refrigerant temperature inside the battery 100 reaches the first preset temperature, then stop heating.

[0038] When the refrigerant inside the battery 100 needs to be heated, the battery 100 is heated until it reaches the first preset temperature.

[0039] S300: Close the first on / off valve 2 and open the second on / off valve 3, then start the compressor 14; After the heating process is completed, the first on / off valve 2 is closed and the second on / off valve 3 is opened to cut off the circulation path, leaving only the outlet of battery 100 to output refrigerant. The compressor 14 is then turned on to extract the refrigerant from battery 100, allowing the refrigerant in battery 100 to enter the components of refrigeration circuit 1.

[0040] S400: The pressure measuring mechanism monitors the refrigerant pressure inside the battery 100 in real time until the refrigerant pressure inside the battery 100 is lower than the first preset pressure, then closes the second on / off valve 3.

[0041] The pressure measuring mechanism continuously monitors the refrigerant pressure inside the battery 100. By measuring the refrigerant pressure inside the battery 100, it determines the amount of refrigerant remaining inside the battery 100. When the internal pressure is lower than the first preset pressure, it indicates that the refrigerant inside the battery 100 has been basically evacuated. At this time, the refrigerant inside the battery 100 has basically entered the components of the refrigeration circuit 1. Then, the second on / off valve 3 is closed to prevent the refrigerant from flowing back into the battery 100.

[0042] S500: Connect the refrigerant recovery port of the refrigerant recovery machine to the liquid storage tank 16 and the gas-liquid separator 13 simultaneously, and turn on the refrigerant recovery machine; at the same time, the temperature measuring mechanism detects the refrigerant temperature in the liquid storage tank 16 and the gas-liquid separator 13 respectively, and determines whether the refrigerant temperature in the liquid storage tank 16 and / or the gas-liquid separator 13 is lower than the second preset temperature; if the refrigerant temperature in at least one of the liquid storage tank 16 and the gas-liquid separator 13 is lower than the second preset temperature, proceed to step S600; if the refrigerant temperature in both the liquid storage tank 16 and the gas-liquid separator 13 is higher than the second preset temperature, proceed to step S700.

[0043] After the refrigerant in battery 100 enters the components of refrigeration circuit 1, it merges with the refrigerant originally remaining in the components of refrigeration circuit 1. At this point, the refrigerant recovery machine can be activated for overall recovery. The recovery port of the refrigerant recovery machine is simultaneously connected to the liquid storage tank 16 and the gas-liquid separator 13, and the machine is activated for overall refrigerant recovery. Since the refrigerant originally remaining in the liquid storage tank 16 and the gas-liquid separator 13 may be in a low-temperature liquid state, the temperature measuring mechanism detects the refrigerant temperature in the liquid storage tank 16 and the gas-liquid separator 13 during the refrigerant recovery process. This allows for determination of the internal refrigerant state in the liquid storage tank 16 and the gas-liquid separator 13. If the refrigerant temperature in the liquid storage tank 16 and / or the gas-liquid separator 13 is lower than the second pre-set temperature, the machine will detect the refrigerant temperature. If the temperature of the refrigerant inside at least one of the liquid storage tank 16 and the gas-liquid separator 13 is lower than the second preset temperature, it indicates that there is low-temperature liquid refrigerant in the liquid storage tank 16 and / or the gas-liquid separator 13. In this case, the liquid storage tank 16 and / or the gas-liquid separator 13 need to be heated, i.e., proceed to step S600. If the refrigerant temperature in both the liquid storage tank 16 and the gas-liquid separator 13 is higher than or equal to the second preset temperature, the heating process in step S600 can be skipped and the process can proceed directly to step S700. Since the refrigerant in the battery 100 has already entered the components of the refrigeration circuit 1, even if the liquid storage tank 16 and / or the gas-liquid separator 13 needs to be heated at this time, the refrigerant recovery machine can remain running to first recover the refrigerant in the refrigeration circuit 1 that originally belonged to the battery 100.

[0044] S600, turn on the heater 6 on the liquid storage tank 16 and / or the gas-liquid separator 13 until the temperature of the liquid storage tank 16 and the gas-liquid separator 13 both reach the second preset temperature.

[0045] Directional heating is applied to the liquid storage tank 16 and / or the gas-liquid separator 13 to promote the vaporization of the internal refrigerant, eliminate dead zones in the recovery process, and ensure that the refrigerant in all components of the system can be efficiently recovered until the temperatures of the liquid storage tank 16 and the gas-liquid separator 13 both reach the second preset temperature.

[0046] S700, the pressure measuring mechanism monitors the refrigerant pressure in refrigeration circuit 1 in real time until the refrigerant pressure in refrigeration circuit 1 is lower than the second preset pressure, then shuts down the refrigerant recovery machine.

[0047] During the refrigerant recovery process, the pressure measuring mechanism monitors the refrigerant pressure in refrigeration circuit 1 in real time. The amount of refrigerant remaining is determined by the refrigerant pressure in refrigeration circuit 1. When the internal pressure is lower than the second preset pressure, it indicates that the refrigerant in each component of refrigeration circuit 1 has been basically exhausted. At this time, the refrigerant recovery machine is turned off, and the refrigerant recovery is completed.

[0048] The specific values ​​of the first and second preset temperatures can be determined based on the saturated vapor pressure-temperature characteristic curve of the refrigerant. The specific value of the first preset pressure is the pressure threshold for determining whether the refrigerant recovery within battery 100 is complete. This value needs to be set according to the system's recovery requirements, equipment capacity, and environmental conditions. The second preset pressure is the pressure threshold for determining whether the overall system recovery is complete, and it can also be set according to the system's recovery requirements, equipment capacity, and environmental conditions.

[0049] In the refrigerant recovery method proposed in this embodiment, the refrigerant in the battery 100 is recovered first, and then the refrigerant in the entire refrigeration circuit 1 is recovered. This allows for batch processing of the refrigerant in the system, enabling the recovery of the refrigerant in the entire battery thermal management test system. It also avoids the inefficiency of one-time recovery. Furthermore, during the recovery process, the refrigerant pressure in the battery 100 and refrigeration circuit 1 is monitored in real time by a pressure measuring mechanism. Combined with the temperature parameters measured by a temperature measuring mechanism, the start and end points of the recovery process can be precisely controlled to ensure thorough refrigerant recovery and eliminate the refrigerant residue problem caused by dead zones in the system.

[0050] Furthermore, the temperature measuring mechanism includes a first temperature measuring element 41 and a second temperature measuring element 42. The first temperature measuring element 41 is connected to the inlet pipe of the battery 100, and the second temperature measuring element 42 is connected to the outlet pipe of the battery 100. In step S100, the temperature values ​​measured by the first temperature measuring element 41 and the second temperature measuring element 42 are obtained, and the average value of the temperature values ​​of the first temperature measuring element 41 and the second temperature measuring element 42 is calculated to obtain the refrigerant temperature inside the battery 100. The overall temperature of the refrigerant inside the battery 100 is determined by the inlet and outlet temperatures of the battery 100. Similarly, the pressure measuring mechanism includes a first pressure measuring element 51 and a second pressure measuring element 52. The first pressure measuring element 51 is connected to the inlet pipe of the battery 100, and the second pressure measuring element 52 is connected to the outlet pipe of the battery 100. In step S400, the pressure values ​​measured by the first pressure measuring element 51 and the second pressure measuring element 52 are obtained, and the average value of the pressure values ​​of the first pressure measuring element 51 and the second pressure measuring element 52 is calculated to obtain the refrigerant pressure inside the battery 100. The refrigerant pressure inside the battery 100 is determined by the inlet and outlet pressure values ​​of the battery 100.

[0051] Further, in step S200, by opening the first on / off valve 2 and the second on / off valve 3 and starting the compressor 14, the battery 100 is heated. When the refrigerant temperature inside the battery 100 reaches the first preset temperature, the compressor 14 is turned off. The system's built-in compressor 14 is then started to compress the refrigerant inside the battery 100, initiating the overall cycle heating.

[0052] Furthermore, a first control valve 7 is connected between the refrigerant recovery port of the refrigerant recovery machine and the liquid storage tank 16, and a second control valve 8 is connected between the refrigerant recovery port of the refrigerant recovery machine and the gas-liquid separator 13. In step S500, by opening the first control valve 7 and the second control valve 8, the refrigerant recovery port of the refrigerant recovery machine is simultaneously connected to the liquid storage tank 16 and the gas-liquid separator 13. The control valve is one of the safety components in the refrigerant recovery system, which can automatically release pressure when the system pressure exceeds the set value, protecting the safety of the equipment and operators.

[0053] In another embodiment, when only the internal refrigerant of battery 100 needs to be recovered, the recovery method includes: S1. The temperature measuring mechanism detects the refrigerant temperature inside the battery 100 and determines whether the refrigerant temperature inside the battery 100 is lower than the first preset temperature. If the refrigerant temperature inside the battery 100 is lower than the first preset temperature, then proceed to step S2. S2. Close the first on / off valve 2 and open the second on / off valve 3, and start the compressor 14; at the same time, the pressure measuring mechanism monitors the refrigerant pressure in the battery 100 in real time until the refrigerant pressure in the battery 100 is lower than the first preset pressure. S3. Close the second shut-off valve 3 and shut off the compressor 14.

[0054] In this embodiment, only the internal refrigerant of the battery 100 is recovered, and the overall circulation temperature rise is not considered. When the temperature of the refrigerant in the battery 100 is lower than the first preset temperature, the first on-off valve 2 is closed and the second on-off valve 3 is opened to cut off the circulation path. Only the outlet of the battery 100 is allowed to output refrigerant. The compressor 14 is turned on to directly extract the refrigerant in the battery 100, so that the refrigerant in the battery 100 enters the gas-liquid separator 13 and the liquid storage tank 16 in the refrigeration circuit 1.

[0055] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A battery thermal management testing system, comprising a refrigeration circuit (1) and a refrigerant recovery unit, wherein the refrigeration circuit (1) comprises a gas-liquid separator (13), a compressor (14), and a liquid storage tank (16) connected in sequence, a first on / off valve (2) is connected between the inlet of the battery (100) and the outlet of the liquid storage tank (16), and a second on / off valve (3) is connected between the outlet of the battery (100) and the inlet of the gas-liquid separator (13), characterized in that, The battery thermal management test system also includes a temperature measuring mechanism and a pressure measuring mechanism. The temperature measuring mechanism is used to detect the refrigerant temperature in the battery (100), the gas-liquid separator (13), and the liquid storage tank (16), respectively. The pressure measuring mechanism is used to detect the refrigerant pressure in the battery (100) and the refrigeration circuit (1), respectively. Heaters (6) are connected to both the gas-liquid separator (13) and the liquid storage tank (16). The refrigerant recovery port of the refrigerant recovery machine can be connected to or disconnected from the liquid storage tank (16) and the gas-liquid separator (13) at the same time.

2. The battery thermal management testing system according to claim 1, characterized in that, The temperature measuring mechanism includes a first temperature measuring element (41) and a second temperature measuring element (42). The first temperature measuring element (41) is connected to the inlet pipe of the battery (100) and is used to measure the refrigerant temperature at the inlet of the battery (100). The second temperature measuring element (42) is connected to the outlet pipe of the battery (100) and is used to measure the refrigerant temperature at the outlet of the battery (100). And / or, the pressure measuring mechanism includes a first pressure measuring element (51) and a second pressure measuring element (52), the first pressure measuring element (51) being connected to the inlet pipe of the battery (100) for measuring the pressure value at the inlet of the battery (100), and the second pressure measuring element (52) being connected to the outlet pipe of the battery (100) for measuring the pressure value at the outlet of the battery (100).

3. The battery thermal management testing system according to claim 1, characterized in that, The temperature measuring mechanism also includes a third temperature measuring element (43) and a fourth temperature measuring element (44). The third temperature measuring element (43) is connected to the gas-liquid separator (13), and the fourth temperature measuring element (44) is connected to the liquid storage tank (16).

4. The battery thermal management testing system according to claim 1, characterized in that, The pressure measuring mechanism also includes a third pressure measuring element (53), and the refrigeration circuit (1) also includes a first throttle valve (18). The first throttle valve (18) is located between the liquid storage tank (16) and the first on / off valve (2). The third pressure measuring element (53) is disposed on the refrigeration circuit (1) and connected to the pipeline between the liquid storage tank (16) and the first throttle valve (18).

5. The battery thermal management testing system according to claim 1, characterized in that, A first control valve (7) is connected between the refrigerant recovery port of the refrigerant recovery machine and the liquid storage tank (16), and a second control valve (8) is connected between the refrigerant recovery port of the refrigerant recovery machine and the gas-liquid separator (13).

6. A refrigerant recovery method, characterized in that, The refrigerant recovery method, applied to the battery thermal management test system as described in any one of claims 1-5, comprises the following steps: S100: The temperature measuring mechanism detects the refrigerant temperature inside the battery (100) and determines whether the refrigerant temperature inside the battery (100) is lower than the first preset temperature; if the refrigerant temperature inside the battery (100) is lower than the first preset temperature, then step S200 is executed; if the refrigerant temperature inside the battery (100) is higher than or equal to the first preset temperature, then step S300 is executed. S200: Heat the battery (100) until the temperature of the refrigerant inside the battery (100) reaches the first preset temperature, then stop heating; S300, Close the first on / off valve (2) and open the second on / off valve (3), and start the compressor (14); S400. The pressure measuring mechanism detects the refrigerant pressure in the battery (100) in real time until the refrigerant pressure in the battery (100) is lower than the first preset pressure, and then closes the second on / off valve (3). S500: Connect the refrigerant recovery port of the refrigerant recovery machine to the liquid storage tank (16) and the gas-liquid separator (13) simultaneously, and turn on the refrigerant recovery machine; at the same time, the temperature measuring mechanism detects the refrigerant temperature in the liquid storage tank (16) and the gas-liquid separator (13) respectively, and determines whether the refrigerant temperature in the liquid storage tank (16) and / or the gas-liquid separator (13) is lower than the second preset temperature; if the refrigerant temperature of at least one of the liquid storage tank (16) and the gas-liquid separator (13) is lower than the second preset temperature, proceed to step S600; if the refrigerant temperature in both the liquid storage tank (16) and the gas-liquid separator (13) is higher than or equal to the second preset temperature, proceed to step S700; S600, turn on the heater (6) on the liquid storage tank (16) and / or the gas-liquid separator (13) until the refrigerant temperature in the liquid storage tank (16) and the gas-liquid separator (13) reaches the second preset temperature; S700, the pressure measuring mechanism detects the refrigerant pressure in the refrigeration circuit (1) in real time until the refrigerant pressure in the refrigeration circuit (1) is lower than the second preset pressure, and then shuts down the refrigerant recovery machine.

7. The refrigerant recovery method according to claim 6, characterized in that, The temperature measuring mechanism includes a first temperature measuring element (41) and a second temperature measuring element (42). The first temperature measuring element (41) is connected to the inlet pipe of the battery (100), and the second temperature measuring element (42) is connected to the outlet pipe of the battery (100). In step S100, the temperature values ​​measured by the first temperature measuring element (41) and the second temperature measuring element (42) are obtained, and the average value of the temperature values ​​measured by the first temperature measuring element (41) and the second temperature measuring element (42) is calculated to obtain the refrigerant temperature inside the battery (100).

8. The refrigerant recovery method according to claim 6, characterized in that, In step S200, the battery (100) is heated by opening the first on / off valve (2) and the second on / off valve (3) and turning on the compressor (14). When the refrigerant temperature in the battery (100) reaches the first preset temperature, the compressor (14) is turned off.

9. The refrigerant recovery method according to claim 6, characterized in that, The pressure measuring mechanism includes a first pressure measuring element (51) and a second pressure measuring element (52). The first pressure measuring element (51) is connected to the inlet pipe of the battery (100), and the second pressure measuring element (52) is connected to the outlet pipe of the battery (100). In step S400, the pressure values ​​measured by the first pressure measuring element (51) and the second pressure measuring element (52) are obtained, and the average value of the pressure values ​​measured by the first pressure measuring element (51) and the second pressure measuring element (52) is calculated to obtain the refrigerant pressure in the battery (100).

10. The refrigerant recovery method according to claim 6, characterized in that, A first control valve (7) is connected between the refrigerant recovery port of the refrigerant recovery machine and the liquid storage tank (16), and a second control valve (8) is connected between the refrigerant recovery port of the refrigerant recovery machine and the gas-liquid separator (13). In step S500, by opening the first control valve (7) and the second control valve (8), the refrigerant recovery port of the refrigerant recovery machine is simultaneously connected to the liquid storage tank (16) and the gas-liquid separator (13).

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