Immersed cell liquid leakage monitoring control system and method

Abstract

The invention discloses an immersed cell liquid leakage monitoring control system which comprises an energy storage EMS, a conductivity sensor arranged in a battery pack, and electromagnetic valves arranged at an immersion liquid inlet and an immersion liquid outlet of the battery pack, the conductivity sensor is used for collecting the conductivity of the immersion liquid of the battery pack in real time, and the conductivity sensor is used for collecting the conductivity of the immersion liquid of the battery pack. The conductivity sensor transmits the collected conductivity to the energy storage EMS, and the energy storage EMS compares the received conductivity with the conductivity range of the immersion liquid stored in the energy storage EMS and controls the electromagnetic valves at the inlet and the outlet of the corresponding battery pack according to the comparison result. The invention further discloses a liquid leakage monitoring and controlling method for the immersed battery cell. According to the invention, the electrical conductivity of the immersion liquid and the voltage of the battery cell are comprehensively judged, so that the leakage of the battery cell can be accurately monitored and controlled, the leakage can be immediately monitored once the leakage of the battery cell occurs, the circulation of the polluted immersion liquid is timely cut off under the control of the energy storage EMS, and other battery packs are prevented from being polluted to cause adverse effects.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage batteries, and in particular to an immersion-type battery cell leakage monitoring control system and method. Background Art

[0002] Immersed battery packs completely immerse the entire battery cell group in a special cooling medium, and achieve cooling by direct contact between the battery cell and the cooling medium. Battery cell leakage refers to the phenomenon that the electrolyte inside the battery cell leaks into the battery pack. Substances that may be produced when the battery cell leaks include solvent vapor in the electrolyte, lithium salt particles, sulfuric acid vapor, alkaline vapor, and corrosion products, etc. These substances are likely to affect the performance and safety of the battery unit: 1. After the battery cell leaks, it may cause a short circuit. Since the components in the electrolyte are conductive, once it leaks into the battery pack, it may come into contact with other components in the battery pack, causing a short circuit. The short circuit may cause overheating and increase the risk of fire and explosion.

[0003] 2. After the battery cell leaks, the leaked electrolyte may circulate with the cooling medium and spread from one battery pack to another, thereby contaminating multiple battery packs in the entire system, and then the immersion liquid of the entire system needs to be replaced, increasing maintenance costs and downtime.

[0004] 3. After the battery cell leaks, it may affect the battery performance. The components in the electrolyte may affect the performance of the immersion liquid, change its thermal conductivity and chemical stability, resulting in a decrease in the thermal management efficiency of the entire system and affecting the battery performance.

[0005] 4. The components in the electrolyte may be corrosive and may corrode the materials inside the battery pack, causing damage to the internal structure of the battery pack and affecting the safety and service life of the battery pack. Summary of the invention

[0006] In order to overcome the shortcomings of the prior art, one of the objects of the present invention is to provide an immersed battery cell leakage monitoring and control system to monitor and control the battery cell leakage in real time to avoid adverse effects. The second object of the present invention is to provide an immersed battery cell leakage monitoring and control method.

[0007] The technical solution adopted by the present invention is as follows: An immersion cell leakage monitoring and control system comprises an energy storage EMS, a conductivity sensor arranged in a battery pack, and solenoid valves arranged at the inlet and outlet of the battery pack immersion liquid. The conductivity sensor is used to collect the conductivity of the battery pack immersion liquid in real time. The conductivity sensor transmits the collected conductivity to the energy storage EMS. The energy storage EMS compares the received conductivity with the conductivity range of the immersion liquid stored in the energy storage EMS, and controls the solenoid valves at the inlet and outlet of the corresponding battery pack according to the comparison result.

[0008] The present invention uses a conductivity sensor to monitor the conductivity of the immersion liquid in real time. Since the electrolyte in the battery core is conductive, if the battery core leaks, the electrolyte will enter the immersion liquid, and the conductivity of the immersion liquid will change, so that the leakage of the battery core can be detected by detecting the conductivity of the immersion liquid. Once the battery core leaks, the energy storage EMS can be used to timely control the electromagnetic valves at the inlet and outlet of the corresponding battery pack to prevent the contaminated immersion liquid in the battery pack from flowing into other battery packs along the circulation system, contaminating other battery packs, and thus avoiding adverse effects.

[0009] As a preferred embodiment of the present invention, it also includes an energy storage BMS, which is used to collect the voltage of each battery cell in real time. The energy storage BMS transmits the collected voltage to the energy storage EMS. The energy storage EMS comprehensively determines the battery cell leakage of the corresponding battery pack based on the received voltage and conductivity, and controls the solenoid valves of the inlet and outlet of the corresponding battery pack based on the result.

[0010] The leakage monitoring of the present invention adopts a comprehensive judgment method, which can greatly improve the accuracy of monitoring. Since the leakage of the battery cell may be a small amount of leakage that makes it difficult for the sensor to identify, by adding the judgment of the battery cell voltage, if the battery cell voltage is also within the normal range of charge and discharge, when both conditions are met at the same time, it can be determined that the battery cell has no leakage. On the contrary, if the battery cell voltage changes, a small amount of leakage may occur. At this time, the corresponding battery pack needs to be closed and the battery pack needs to be checked, thereby avoiding the situation where a small amount of leakage occurs and is difficult to identify, and greatly improving the accuracy of monitoring.

[0011] As a preferred embodiment of the present invention, the energy storage EMS performs an initial judgment based on the received conductivity; if the measured conductivity is within the normal conductivity range, the energy storage EMS enters a secondary judgment; if the measured conductivity exceeds the normal conductivity range, the energy storage EMS issues an instruction to close the solenoid valves at the inlet and outlet of the corresponding battery pack.

[0012] The present invention first determines whether the conductivity is within the normal range. If it exceeds the normal range, since the battery pack is sealed and will not be contaminated by the outside world, once it exceeds the normal range, it indicates that the battery cell has leaked. On the contrary, if the conductivity is within the normal range, it does not indicate that the battery cell in the battery pack has not leaked. If there is only a small amount of leakage, the sensor may be difficult to identify. Therefore, a secondary judgment is required to improve the monitoring accuracy.

[0013] As a preferred embodiment of the present invention, the secondary judgment is to judge whether the voltage of each battery cell is within the normal range of charge / discharge; if so, the energy storage EMS will further control the opening of the solenoid valve to achieve temperature control of the energy storage battery; if not, the energy storage EMS will issue an instruction to close the solenoid valves at the inlet and outlet of the corresponding battery pack.

[0014] In the present invention, the premise of the secondary judgment is that the conductivity is within the normal range, and the battery cell may not leak or leak a small amount of liquid. If the battery cell leaks a small amount of liquid, it will affect the voltage. Therefore, it can be determined through the secondary judgment of the battery cell voltage. If the voltage is also within the normal range, it indicates that the battery cell has not leaked, and the energy storage EMS will further control the opening of the solenoid valve to regulate the temperature of the energy storage battery; on the contrary, if it exceeds the normal range, it indicates that the voltage may be affected by the leakage of the battery cell, that is, there may be a small amount of leakage. At this time, it is necessary to close the solenoid valve of the corresponding battery pack and check the battery pack to avoid adverse effects.

[0015] As a preferred embodiment of the present invention, the energy storage BMS is used to collect the temperature of each battery cell in real time. The energy storage BMS transmits the collected temperature to the energy storage EMS. The energy storage EMS determines the temperature of each battery pack according to the received temperature. The energy storage EMS compares the battery pack temperature with the normal temperature range of the battery pack stored in the energy storage EMS. If the battery pack temperature exceeds the normal temperature range, the solenoid valves at the inlet and outlet of the battery pack are controlled to take corresponding measures. If the battery pack temperature is within the normal temperature range, the battery pack is further judged and corresponding measures are taken.

[0016] After determining that the battery cell is not leaking, the present invention can also adjust the temperature of each battery pack by controlling the solenoid valve through the energy storage EMS. Overheating of the battery pack during the charging and discharging process of the energy storage battery may increase the risk of fire and explosion, so it needs to be cooled by immersion liquid. However, due to the different heating levels of different battery packs, the temperature of some battery packs may not be cooled enough and still exceed the normal temperature range, so there may still be certain risks. In this solution, the solenoid valve can be used to make corresponding adjustments for each battery pack, thereby reducing the risk caused by overheating of the battery pack and greatly improving the service life of the battery.

[0017] As a preferred embodiment of the present invention, if the battery pack temperature exceeds the normal temperature range, the energy storage EMS further determines whether the temperature of each battery pack is higher than the maximum allowable value of the battery pack temperature; if so, the energy storage EMS controls the opening of the solenoid valves at the inlet and outlet of the corresponding battery pack to increase; if not, the energy storage EMS determines whether the temperature of each battery pack is lower than the minimum allowable value of the battery pack temperature, and if so, controls the opening of the solenoid valves at the inlet and outlet of the corresponding battery pack to decrease, otherwise, the determination is terminated.

[0018] In the present invention, if the temperature of the battery pack exceeds the normal range, one case is that the temperature is too high. In this case, the opening of the battery valve is increased, the flow of the immersion liquid is increased, and the immersion liquid is fully in contact with the battery cell to improve the heat dissipation efficiency, thereby achieving a further cooling effect. Another case is that the temperature is too low, which indicates excessive heat dissipation. If the temperature of the battery pack is too low, it will affect the charging and discharging efficiency. In this case, the opening of the battery valve is reduced, the flow of the immersion liquid is reduced, and excessive heat dissipation of the battery pack is avoided, so that the temperature of the battery pack is maintained within the normal range.

[0019] As a preferred embodiment of the present invention, if the temperature of the battery pack is within the normal temperature range, the energy storage EMS further determines whether the temperature difference between the battery packs is within the preset temperature difference threshold stored in the energy storage EMS. If so, the process ends; if not, the energy storage EMS identifies the battery packs with the highest and lowest temperatures among all the obtained battery packs, and controls the inlet and outlet solenoid valves of the battery pack with the highest temperature to open wider, and controls the inlet and outlet solenoid valves of the battery pack with the lowest temperature to open narrower.

[0020] The present invention not only ensures that the battery pack is within the normal temperature range, but also takes into account the temperature difference of the components of the battery pack. If the temperature difference between the battery packs of the energy storage battery is too large, it will also affect the battery life and charging and discharging efficiency. In the present invention, the temperature difference of the battery pack is the difference between the highest temperature and the lowest temperature. By comparing the temperature difference of the battery pack with the temperature difference threshold, if it exceeds the temperature difference threshold, the battery pack with the highest temperature is further cooled, and at the same time, the heat dissipation intensity of the battery pack with the lowest temperature is weakened, so that the temperature difference between the battery pack with the highest temperature and the battery pack with the lowest temperature gradually decreases until the threshold is reached, thereby avoiding the adverse effects of excessive temperature difference on the battery.

[0021] A method for monitoring and controlling leakage of submerged battery cells is provided, which applies the above-mentioned monitoring and control system for leakage of submerged battery cells, including real-time acquisition of the conductivity of the battery pack immersion liquid, real-time acquisition of the voltage of each battery cell, comparing the acquired conductivity and voltage with the corresponding stored normal range values, making a comprehensive judgment on the leakage of the battery cell based on the comparison result, and controlling the corresponding solenoid valve to take appropriate measures based on the leakage of the battery cell.

[0022] As a preferred embodiment of the present invention, it also includes real-time collection of the temperature of each battery cell, calculating the temperature of each battery pack based on the collected battery cell temperature, comparing the calculated battery pack temperature with the normal temperature range value of the battery pack, and controlling the corresponding solenoid valve to take appropriate measures based on the comparison result.

[0023] As a preferred embodiment of the present invention, it also includes comparing the temperature differences of all battery packs, comparing the comparison results with the preset temperature difference thresholds again, and controlling the corresponding solenoid valves to take appropriate measures according to the final comparison results.

[0024] Compared with the prior art, the present invention has the following improvements and beneficial effects: The present invention can realize accurate monitoring and control of battery cell leakage through comprehensive judgment of the conductivity of the immersion liquid and the battery cell voltage, ensuring that once a battery cell leaks, it can be immediately monitored; when a battery cell leak is detected, the energy storage EMS can promptly cut off the circulation of the contaminated immersion liquid by controlling the electromagnetic valves at the inlet and outlet, preventing other battery packs from being contaminated and causing adverse effects. In addition, after determining that the battery cell is not leaking, the present invention can also control the electromagnetic valves through the energy storage EMS to adjust the temperature of each battery pack and the temperature between battery packs, so as to ensure daily maintenance of the energy storage battery and increase the service life of the energy storage battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flowchart of the submerged battery leakage monitoring and control process in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially used for illustration purposes rather than for limiting the present invention.

[0027] In the description of the present application, the terms "top", "bottom", "one end", "one side", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the structure referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present application.

[0028] The present embodiment discloses an immersion cell leakage monitoring and control system, comprising an energy storage EMS, an energy storage BMS, a conductivity sensor arranged in a battery pack, and solenoid valves arranged at an inlet and an outlet of an immersion liquid in the battery pack, wherein the conductivity sensor is used to collect the conductivity of the immersion liquid in the battery pack in real time, the energy storage BMS is used to collect the voltage of each battery cell in real time, the conductivity sensor and the energy storage BMS transmit the collected conductivity and voltage to the energy storage EMS, the energy storage EMS stores a normal range value of the conductivity of the immersion liquid and a normal range value of the cell voltage during charge / discharge, the energy storage EMS compares the received conductivity with the normal range value of the immersion liquid, the energy storage EMS further compares the received voltage with the normal range value of the cell voltage during charge / discharge, and controls the opening or closing of the solenoid valves at the inlet and outlet of the corresponding battery pack through comprehensive judgment.

[0029] The energy storage BMS is also used to collect the temperature of each battery cell in real time. The energy storage BMS transmits the collected temperature to the energy storage EMS. After the energy storage EMS screens out all the battery cells in the same battery, it averages the corresponding battery cell temperatures to obtain the temperature of the corresponding battery pack. The energy storage EMS stores the normal temperature range value of the battery pack. The energy storage EMS compares the collected battery pack temperature with the normal temperature range value, and controls the solenoid valves at the inlet and outlet of the corresponding battery pack to take corresponding measures based on the comparison results.

[0030] If the battery pack temperature is within the normal range, the energy storage EMS needs to further compare the temperature difference between the battery packs. The energy storage EMS stores a preset temperature difference threshold or temperature difference range value. The energy storage EMS selects the battery pack with the highest and lowest temperatures among all battery packs, and calculates the temperature difference between the two. Then, the obtained temperature difference is compared with the temperature difference threshold or temperature difference range value, and the solenoid valves at the inlet and outlet of the corresponding battery pack are controlled according to the comparison results to take corresponding measures.

[0031] The monitoring and control system of the present invention can realize accurate monitoring and control of battery cell leakage through comprehensive judgment of the conductivity of the immersion liquid and the battery cell voltage, ensuring that once a battery cell leakage occurs, it can be immediately monitored. When a battery cell leakage is detected, the energy storage EMS can quickly control the corresponding solenoid valve to cut off the circulation of the contaminated immersion liquid in time to prevent other battery packs from being contaminated. If the battery cell is not leaking, the energy storage EMS can further control the solenoid valve to regulate the temperature of each battery pack and the temperature between battery packs, which is beneficial to improve the service life of the energy storage battery.

[0032] This embodiment is based on an immersion cell leakage monitoring and control system and also discloses an immersion cell leakage monitoring and control method. For specific processes, see Figure 1 shown.

[0033] The conductivity sensor in each battery pack collects the conductivity of the immersion fluid in the corresponding battery pack in real time, and transmits the collected conductivity to the energy storage EMS. The energy storage EMS compares the received conductivity with the normal range of the immersion fluid conductivity to determine whether the collected conductivity is within the normal value range: If yes, it means that the battery cells in the battery pack are not leaking, or there is only a small amount of leakage that is not detected by the conductivity sensor. To ensure the accuracy of monitoring, the energy storage EMS makes a secondary judgment on the corresponding battery pack.

[0034] If not, it indicates that the battery cell has leaked. The energy storage EMS will issue a command to close the solenoid valves at the inlet and outlet of the corresponding battery pack to lock the single battery pack so that the battery pack can be inspected.

[0035] The secondary judgment is to judge whether the voltage of each battery cell is within the normal range of charge / discharge. The energy storage BMS collects the voltage of each battery cell in real time and transmits the collected voltage data to the energy storage EMS. The energy storage EMS compares the received voltage data with the normal range of the battery cell voltage during charge / discharge to judge whether the voltage of each battery cell is within the normal range: If so, it means that the battery cell is not leaking, and the energy storage EMS will further control the solenoid valve to achieve temperature regulation of the energy storage battery.

[0036] If not, it means that the voltage may be affected by battery cell leakage, that is, there may be a small amount of leakage. At this time, the energy storage EMS will issue an instruction to close the solenoid valves at the inlet and outlet of the corresponding battery pack so as to inspect the battery pack and prevent the immersion liquid in the battery pack from circulating and contaminating other battery packs, causing adverse effects.

[0037] After confirming that the battery cell is not leaking, the energy storage EMS further controls the solenoid valve. The energy storage BMS is also used to collect the temperature of each battery cell in real time. The energy storage BMS transmits all collected temperatures to the energy storage EMS. After the energy storage EMS screens out all the battery cells in the same battery, it averages the corresponding battery cell temperatures to obtain the temperature of the corresponding battery pack. The energy storage EMS compares the temperature of each battery pack with the normal temperature range of the battery pack to determine whether the temperature of each battery pack is within the normal range: If so, the energy storage EMS further determines the temperature difference of the battery pack components. If the temperature difference between the battery packs of the energy storage battery is too large, it will also affect the battery life and charging and discharging efficiency.

[0038] If not, there are two situations. One is that the temperature is too high. The energy storage EMS determines whether the temperature of the corresponding battery pack is higher than the maximum value of the normal temperature range of the battery pack. If so, the energy storage EMS controls the opening of the electromagnetic valves at the inlet and outlet of the corresponding battery pack to increase, and by increasing the flow of the immersion liquid, the immersion liquid and the battery cell are fully in contact to dissipate heat, thereby improving heat dissipation. If not, it indicates another situation, that is, the temperature is too low. The energy storage EMS determines whether the temperature of the corresponding battery pack is lower than the minimum value of the normal temperature range of the battery pack. If so, the energy storage EMS controls the opening of the electromagnetic valves at the inlet and outlet of the corresponding battery pack to decrease, reduce the flow of the immersion liquid, avoid excessive heat dissipation of the battery pack, and maintain the battery pack temperature within the normal range. If not, it ends.

[0039] After determining that the temperature of the battery pack is within the normal range, the energy storage EMS will further determine the temperature difference of the battery pack components. The energy storage EMS selects the battery pack with the highest temperature and the lowest temperature among all battery packs, and calculates the temperature difference between the two. The energy storage EMS compares the obtained temperature difference with the temperature difference threshold or temperature difference range value of the battery pack to determine whether the temperature difference of the battery pack components is within the normal range: If yes, it means that the temperature of the battery pack has reached the optimum, and the process ends.

[0040] If not, the energy storage EMS controls the inlet and outlet solenoid valves of the battery pack with the highest temperature to open wider to lower the temperature of the battery pack, and controls the inlet and outlet solenoid valves of the battery pack with the lowest temperature to open narrower to increase the temperature of the battery pack, thereby reducing the temperature difference of the battery pack components and increasing the service life of the energy storage battery.

[0041] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. An immersion battery cell leakage monitoring and control system, characterized in that: It includes an energy storage EMS, a conductivity sensor arranged in a battery pack, and solenoid valves arranged at the inlet and outlet of the battery pack immersion liquid. The conductivity sensor is used to collect the conductivity of the battery pack immersion liquid in real time. The conductivity sensor transmits the collected conductivity to the energy storage EMS. The energy storage EMS compares the received conductivity with the conductivity range of the immersion liquid stored in the energy storage EMS, and controls the solenoid valves at the inlet and outlet of the corresponding battery pack according to the comparison result.

2. The submerged battery cell leakage monitoring and control system according to claim 1, characterized in that: It also includes an energy storage BMS, which is used to collect the voltage of each battery cell in real time. The energy storage BMS transmits the collected voltage to the energy storage EMS. The energy storage EMS comprehensively judges the battery cell leakage of the corresponding battery pack based on the received voltage and conductivity, and controls the solenoid valves at the inlet and outlet of the corresponding battery pack based on the results.

3. The submerged battery cell leakage monitoring and control system according to claim 2, characterized in that: The energy storage EMS performs an initial judgment based on the received conductivity; if the measured conductivity is within the normal conductivity range, the energy storage EMS enters a secondary judgment; if the measured conductivity exceeds the normal conductivity range, the energy storage EMS issues an instruction to close the solenoid valves at the inlet and outlet of the corresponding battery pack.

4. The submerged battery cell leakage monitoring and control system according to claim 3, characterized in that: The secondary judgment is to determine whether the voltage of each battery cell is within the normal range of charge / discharge; if so, the energy storage EMS will further control the opening of the solenoid valve to achieve temperature control of the energy storage battery; if not, the energy storage EMS will issue an instruction to close the solenoid valve at the inlet and outlet of the corresponding battery pack.

5. The submerged battery cell leakage monitoring and control system according to claim 4, characterized in that: The energy storage BMS is used to collect the temperature of each battery cell in real time. The energy storage BMS transmits the collected temperature to the energy storage EMS. The energy storage EMS determines the temperature of each battery pack according to the received temperature. The energy storage EMS compares the battery pack temperature with the normal temperature range of the battery pack stored in the energy storage EMS; if the battery pack temperature exceeds the normal temperature range, the solenoid valves at the inlet and outlet of the battery pack are controlled to take corresponding measures; if the battery pack temperature is within the normal temperature range, the battery pack is further judged and corresponding measures are taken.

6. The submerged battery cell leakage monitoring and control system according to claim 5, characterized in that: If the battery pack temperature exceeds the normal temperature range, the energy storage EMS further determines whether the temperature of each battery pack is higher than the maximum allowable value of the battery pack temperature; if so, the energy storage EMS controls the opening of the solenoid valves at the inlet and outlet of the corresponding battery pack to increase; if not, the energy storage EMS determines whether the temperature of each battery pack is lower than the minimum allowable value of the battery pack temperature, and if so, controls the opening of the solenoid valves at the inlet and outlet of the corresponding battery pack to decrease, otherwise, the determination is terminated.

7. The submerged battery cell leakage monitoring and control system according to claim 5, characterized in that: If the temperature of the battery pack is within the normal temperature range, the energy storage EMS further determines whether the temperature difference between the battery packs is within the preset temperature difference threshold stored in the energy storage EMS. If so, the process ends; if not, the energy storage EMS identifies the battery packs with the highest and lowest temperatures among all the obtained battery packs, and controls the inlet and outlet solenoid valves of the battery pack with the highest temperature to open wider, and controls the inlet and outlet solenoid valves of the battery pack with the lowest temperature to open narrower.

8. A method for monitoring and controlling liquid leakage of an immersed battery cell, using the monitoring and control system for liquid leakage of an immersed battery cell as claimed in any one of claims 1 to 7, characterized in that: The method includes real-time collection of the conductivity of the battery pack immersion fluid and the voltage of each battery cell, comparing the collected conductivity and voltage with the corresponding stored normal range values, making a comprehensive judgment on the battery cell leakage situation based on the comparison results, and controlling the corresponding solenoid valve to take appropriate measures according to the battery cell leakage situation.

9. The method for monitoring and controlling liquid leakage of submerged battery cells according to claim 8, characterized in that: It also includes real-time collection of the temperature of each battery cell, calculating the temperature of each battery pack based on the collected battery cell temperature, comparing the calculated battery pack temperature with the normal temperature range value of the battery pack, and controlling the corresponding solenoid valve to take appropriate measures based on the comparison result.

10. The method for monitoring and controlling liquid leakage of submerged battery cells according to claim 9, characterized in that: It also includes comparing the temperature differences of all battery packs, comparing the comparison results with the preset temperature difference thresholds again, and controlling the corresponding solenoid valves to take appropriate measures based on the final comparison results.

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