A cooling circulating water pressure control system and method for fuel cell testing, a fuel cell testing system

Abstract

This invention discloses a cooling circulating water pressure control system and method for fuel cell testing, as well as a fuel cell testing system, aiming to solve key industry problems in the prior art, such as pressure mismatch between cooling water and gas flow channels, delayed response to operating condition fluctuations, and insufficient fault safety protection. It includes a cooling circulation main loop, which comprises a circulating water tank, a circulating pump, a heat exchanger, and the cooling flow channel of the fuel cell under test, connected sequentially by pipelines. It also includes: a pressure acquisition device installed on the cooling circulation main loop for acquiring cooling water pressure signals; a controller electrically connected to the pressure acquisition device, receiving the pressure signals, comparing them with a preset target pressure value, and outputting adjustment commands; and a pressure regulation device. This invention achieves dynamic balance between cooling water pressure and fuel cell stack gas pressure through nitrogen back pressure regulation, while simultaneously superimposing multiple safety interlock mechanisms to ensure the safety and reliability of the entire testing process.

Description

Technical Field

[0001] This invention relates to the field of fuel cell testing technology, and in particular to a cooling circulating water pressure control system and method for fuel cell testing, and a fuel cell testing system. Background Technology

[0002] With the explosive growth in demand for fuel cells from fields such as new energy vehicles and distributed energy storage, the safety, accuracy, and efficiency of fuel cell testing have become core industry requirements. 1. When a fuel cell is running, the anode and cathode gas channels need to maintain a high pressure of 1 to 3 bar to ensure the efficiency of the electrochemical reaction. However, the working pressure of the cooling circulating water system is usually lower than 1 bar. This inherent pressure difference leads to a double safety hazard: when the membrane electrode or channel seal is damaged, high-pressure gas can easily enter the water circulation and cause hydrogen leakage, or the water pressure is too high and the coolant can seep into the gas channel and damage the stack. 2. In the test scenario, operating conditions such as start-stop switching, sudden load changes, and fuel cell replacement occur frequently. The existing system lacks a rapid pressure balancing mechanism, and pressure fluctuations can easily induce safety accidents. 3. Sudden power outages and human error are unavoidable malfunctions. The existing system lacks automatic pressure relief and interlock protection designs, resulting in weak risk control capabilities. 4. The industry's requirements for testing efficiency continue to increase. Traditional operations such as manual drainage and manual pressure calibration can no longer meet the needs of batch testing, and there is an urgent need for automated solutions. Summary of the Invention

[0003] The purpose of this invention is to provide a cooling circulating water pressure control system and method for fuel cell testing, as well as a fuel cell testing system, to solve key industry problems such as pressure mismatch between cooling water and gas flow channels, delayed response to operating condition fluctuations, and insufficient fault safety protection in fuel cell testing.

[0004] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution: In a first aspect, the present invention provides a cooling circulating water pressure control system for fuel cell testing, comprising a cooling circulating main loop, wherein the cooling circulating main loop includes a circulating water tank, a circulating pump, a heat exchanger, and a cooling flow channel of the fuel cell under test connected sequentially by pipelines, and further includes: A pressure acquisition device is installed on the main cooling loop to acquire cooling water pressure signals; The controller is electrically connected to the pressure acquisition device, receives the pressure signal, compares and calculates it with a preset target pressure value, and outputs an adjustment command. Gas source; The pressure regulating device has its inlet connected to the gas source, its outlet connected to the main cooling cycle circuit, and its control terminal electrically connected to the controller. The pressure regulating device adjusts the amount of gas injected into the main cooling cycle circuit according to the regulating command, so as to dynamically adjust the cooling water pressure.

[0005] Through the above technical solutions, the control system can achieve precise control of the cooling circulating water pressure, ensuring that the fuel cell maintains a stable working environment during testing; through real-time monitoring and dynamic adjustment, it effectively avoids the impact of pressure fluctuations on test results, improving the accuracy and reliability of test data.

[0006] Optionally, the pressure acquisition device is installed on the pipeline on the inlet side of the cooling channel.

[0007] Optionally, the outlet of the pressure regulating device is connected to the pipeline on the inlet side of the circulating pump.

[0008] Optionally, the controller is a programmable logic controller with a built-in PID control algorithm for calculating the adjustment command in real time based on the deviation between the pressure signal and the target pressure value.

[0009] Optionally, the system also includes a safety interlock unit, which includes: a pressure relief device installed on the main cooling loop for automatically opening to release pressure when the system pressure exceeds a preset threshold; and an emergency pressure relief valve installed on the circulating water tank and electrically connected to the controller for automatically opening to reduce system pressure when a pressure relief command is received from the controller or when the system is powered off.

[0010] The safety interlock unit design ensures the system can react promptly in abnormal situations, protecting the safety of equipment and operators. The pressure relief device monitors system pressure in real time; if the pressure exceeds the safe range, it will quickly activate and perform necessary pressure relief operations. The emergency pressure relief valve provides additional protection, automatically opening to release excessive pressure in emergencies such as controller commands or sudden power outages, effectively preventing various dangers that may arise from uncontrolled pressure.

[0011] Optionally, the control system further includes: a first switching valve disposed between the gas source and the pressure regulating device, the control terminal of the first switching valve being electrically connected to the controller; the safety interlock unit further includes: a gas leak sensor disposed on the circulating water tank and electrically connected to the controller, used to detect the concentration of leaked combustible gas; the controller is configured to, in response to the concentration detected by the gas leak sensor exceeding a preset threshold, execute an interlock action of closing the first switching valve, opening the emergency pressure relief valve, and triggering an alarm.

[0012] When the system is operating normally, the controller continuously monitors the data from the gas leak sensors to ensure system safety. In the event of a leak, the controller will not only execute the aforementioned interlocking actions, but also record information such as the time and concentration of the leak event and transmit it to the remote monitoring system so that maintenance personnel can analyze and handle it promptly.

[0013] Optionally, the system further includes a purging and drainage unit, which comprises: a drain valve located at the low-level drain port of the main cooling circulation loop; and an isolation valve located on the pipeline at the outlet side of the cooling channel. The controller is electrically connected to the drain valve and the isolation valve and is configured to, upon receiving a drainage command, sequentially execute the following actions: stopping the circulation pump, closing the isolation valve, and controlling the pressure regulating device to inject gas into the main cooling circulation loop to purge and drain the cooling channel, and closing the drain valve after drainage is completed.

[0014] By precisely controlling the drainage and purging process, residual liquid in the cooling channels is thoroughly removed, thus avoiding corrosion or freezing problems caused by liquid residue and improving the system's reliability and service life. Furthermore, the control system can adjust parameters according to different working environments and requirements to achieve suitable cooling effects and resource utilization.

[0015] Optionally, the purging and drainage unit further includes a flow monitoring module, which is located on the outlet side of the drain valve and electrically connected to the controller, for detecting the drainage status.

[0016] In a second aspect, the present invention also provides a fuel cell testing system, including an automatic control system for cooling circulating water pressure for fuel cell testing as described in any of the preceding claims.

[0017] Thirdly, the present invention also provides an automatic control method for cooling circulating water pressure for fuel cell testing, based on the aforementioned cooling circulating water pressure control system for fuel cell testing, with a controller as the executing entity, and including the following steps: Receive the cooling water pressure signal in the main cooling loop, which is collected in real time by the pressure acquisition device; The received real-time pressure signal is compared with the preset target pressure value to generate an adjustment command; The adjustment command is sent to the pressure regulating device to control the pressure regulating device to adjust the amount of gas injected into the main cooling loop, thereby dynamically adjusting the cooling water pressure. Repeat the above steps to stabilize the cooling water pressure within the allowable error range of the target pressure value.

[0018] Compared with the prior art, the beneficial effects achieved by the cooling circulating water pressure control system and method for fuel cell testing, and the fuel cell testing system of the present invention are as follows: 1. This invention solves the problems of manual operation, low accuracy, and slow response in traditional systems by constructing a fully closed-loop automatic control logic of "real-time pressure signal acquisition + dynamic calculation by the control unit + precise adjustment by the actuator + pressure status feedback verification". The pressure acquisition device monitors the inlet water pressure in real time, the controller quickly calculates the adjustment amount through a PID algorithm, and the pressure regulation device precisely controls the nitrogen injection amount according to the instructions, realizing a dynamic balance between cooling water pressure and fuel cell stack gas pressure, which significantly improves the stability and data reliability of the testing process; 2. This invention achieves comprehensive protection against fault conditions such as overpressure, power failure, and gas leakage through the setting of safety interlock units: the pressure relief device automatically opens when the system is overpressured, achieving mechanical passive protection; the emergency pressure relief valve actively opens upon receiving a control command or when the system is powered off, ensuring rapid release of system pressure under fault conditions; the gas leakage sensor monitors the hydrogen concentration in real time, and triggers interlock actions of shutting off the gas source, opening the pressure relief valve, and alarming once the concentration exceeds the limit. The synergistic effect of these three protection mechanisms significantly improves the system's fault tolerance capability and safety level. 3. Through the design of the purging and drainage unit, this invention automatically performs the entire process of shutdown, valve closure, purging, and drainage during fuel cell stack replacement without manual intervention. This significantly shortens the test interval time, meets the efficiency requirements of batch testing scenarios, and eliminates the errors and time consumption caused by manual calibration, further improving test efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of a cooling circulating water pressure control system for fuel cell testing, provided in some embodiments of the present invention. Figure 2 This is a flowchart of a cooling circulating water pressure control method for fuel cell testing, provided in some embodiments of the present invention.

[0021] Explanation of reference numerals in the attached figures: 1. Fuel cell under test; 2. Solenoid valve one; 3. Electronic proportional valve; 4. Circulating water tank; 5. Solenoid valve two; 6. Hydrogen concentration sensor; 7. Unloading valve; 8. Pressure sensor; 9. Solenoid valve three; 10. Heat exchanger; 11. Circulating pump; 12. Solenoid valve four; 13. Cooling circulating water outlet line; 14. Cooling circulating water inlet line; 15. Nitrogen line. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Example

[0023] like Figure 1 As shown, this embodiment provides a cooling circulating water pressure control system for fuel cell testing, including a cooling circulating main loop. The cooling circulating main loop includes a cooling channel for a circulating water tank 4, a circulating pump 11, a heat exchanger 10, and a fuel cell 1 under test, which are connected in sequence by pipelines. The circulating water tank 4, the variable frequency circulating pump 11, the plate heat exchanger 10, and the fuel cell 1 under test are connected in sequence by stainless steel pipelines to form a cooling water circulating channel. The cooling water inlet side of the fuel cell 1 under test is defined as the cooling circulating water inlet pipeline 14, and the outlet side is defined as the cooling circulating water outlet pipeline 13. The pipelines use compression fittings to ensure sealing and corrosion resistance, providing a basic environment for stable pressure regulation.

[0024] Also includes: A pressure acquisition device is installed on the main cooling circulation loop to acquire cooling water pressure signals. A diffused silicon pressure sensor 8 is installed on the cooling circulation water inlet pipeline 14 at a distance of ≤50cm from the fuel cell inlet to acquire the inlet water pressure signal in real time, ensuring the authenticity and timeliness of the signal acquisition.

[0025] The controller is electrically connected to the pressure acquisition device, receives the pressure signal, compares and calculates it with a preset target pressure value, and outputs an adjustment command. Gas source: Nitrogen gas is used to provide back pressure regulation medium. A precision filter is added to the front end of nitrogen line 15 to prevent impurities from entering electronic proportional valve 3 and affecting valve regulation accuracy and service life.

[0026] A pressure regulating device has its inlet connected to the gas source, its outlet connected to the main cooling cycle circuit, and its control terminal electrically connected to the controller. The pressure regulating device adjusts the amount of gas injected into the main cooling cycle circuit according to the regulating command, thereby dynamically adjusting the cooling water pressure. The pressure regulating device employs a high-precision electronic proportional valve 3, whose inlet is connected to a nitrogen source.

[0027] In summary, the cooling circulating water pressure control system for fuel cell testing in this embodiment, when the system is working, the pressure sensor 8 collects the infeed water pressure signal in real time and transmits it to the PLC, calculates the adjustment amount, sends a command to the electronic proportional valve 3, the electronic proportional valve 3 adjusts the nitrogen injection amount, the pressure sensor 8 continuously feeds back the signal, and the PLC dynamically calibrates and adjusts, forming a complete closed-loop control circuit.

[0028] In some embodiments, the pressure acquisition device is disposed on the pipeline at the inlet side of the cooling channel. It is understood that the pressure sensor 8 is vertically installed on the cooling circulating water inlet pipeline 14 on the inlet side of the cooling channel via a compression fitting. The probe of the pressure sensor 8 is perpendicular to the water flow direction to reduce the impact of water flow impact on detection accuracy. Shielded cables are used for the signal cable to avoid electromagnetic interference.

[0029] By collecting pressure data in real time through pressure sensor 8, the system can respond to pressure changes in a timely manner and adjust system parameters to adapt to different working conditions. This not only improves the efficiency of the cooling system, but also reduces the potential risk of failure caused by pressure fluctuations.

[0030] In some embodiments, the outlet of the pressure regulating device is connected to the pipeline on the inlet side of the circulating pump 11. It can be understood that the outlet of the electronic proportional valve 3 is preferably connected to the pipeline between the inlet of the circulating pump 11 and the circulating water tank 4 (≤30cm from the inlet of the circulating pump 11) to ensure that nitrogen and cooling water are fully mixed, to uniformly establish system back pressure, and to avoid local pressure fluctuations.

[0031] In some embodiments, the controller is a programmable logic controller (PLC) with a built-in PID control algorithm for calculating the adjustment command in real time based on the deviation between the pressure signal and the target pressure value. It can be understood that by using a PLC as the core controller and incorporating a built-in PID closed-loop control algorithm, the collected water pressure signal is compared with a preset target pressure value (set according to the fuel cell gas pressure, typically 0.1-0.2 bar lower), and a precise adjustment command is output.

[0032] In some embodiments, a safety interlock unit is further included, comprising: a pressure relief device disposed on the main cooling circulation loop, for automatically opening to relieve pressure when the system pressure exceeds a preset threshold; and an emergency pressure relief valve disposed on the circulating water tank 4 and electrically connected to the controller, for automatically opening upon receiving a pressure relief command from the controller or when the system is powered off, to reduce the system pressure. Optionally, the control system further includes: a first switching valve disposed between the gas source and the pressure regulating device, the control terminal of the first switching valve being electrically connected to the controller; the safety interlock unit further includes: a gas leak sensor disposed on the circulating water tank 4 and electrically connected to the controller, for detecting the concentration of leaked combustible gas; the controller is configured to, in response to the concentration detected by the gas leak sensor exceeding a preset threshold, execute an interlock action of closing the first switching valve, opening the emergency pressure relief valve, and triggering an alarm.

[0033] It can be understood that the gas leak sensor is a hydrogen concentration sensor 6, the pressure relief device is a pressure relief valve, the emergency pressure relief valve is a solenoid valve 2 5, and the first switching valve is a solenoid valve 1 2. Solenoid valve 1 2 is located on the pipeline between nitrogen and electronic proportional valve 3. It is a two-position two-way solenoid directional valve and a normally closed directional valve. The control terminal of solenoid valve 1 2 is electrically connected to the digital output module of the controller. The controller drives the solenoid valve coil to switch on and off through a relay or solid-state relay.

[0034] A spring-loaded unloading valve 7 is installed on the connecting pipe of the circulating water tank 4. When the system pressure exceeds the limit, it will automatically depressurize within 1 second. At the same time, the controller will cut off the solenoid valve 2, stop the nitrogen supply, and trigger an audible and visual alarm. Power failure interlock: Install normally open solenoid valve 2 5 on the top of the circulating water tank 4. When the system is powered off, the solenoid valve will open and reduce the system pressure to normal pressure within 3 seconds, which will stop the circulating pump 11 and prevent pressure from accumulating. Leakage Interlock: A hydrogen concentration sensor 6 is installed on the top of the circulating water tank 4. When a hydrogen leak is detected, the sensor will trigger a linkage action of "opening solenoid valve 25 to release pressure + closing solenoid valve 12 to cut off gas supply + alarm" within 0.1 seconds to curb the risk of leakage.

[0035] In some embodiments, a purging and drainage unit is further included, comprising: a drain valve disposed at a low-level drain port of the main cooling circulation loop; an isolation valve disposed on a pipe at the outlet side of the cooling channel; the controller is electrically connected to the drain valve and the isolation valve, and is configured to, upon receiving a drainage command, sequentially execute the following actions: stopping the circulation pump 11, closing the isolation valve, and controlling the pressure regulating device to inject gas into the main cooling circulation loop to purge and drain the cooling channel, and closing the drain valve after drainage is completed. Optionally, the purging and drainage unit further includes a flow monitoring module disposed at the outlet side of the drain valve and electrically connected to the controller, for detecting the drainage status.

[0036] It is understood that the drain valve is solenoid valve 3-9 and the isolation valve is solenoid valve 4-12. To adapt to batch testing requirements, an automated drainage process is designed based on the pressure regulation principle: Solenoid valve 4-12 (solenoid shut-off valve, sealing pressure ≥4 bar) is installed on the cooling circulating water outlet pipeline 13, and solenoid valve 3-9 (purge drain valve, drainage flow rate ≥1 L / s) is installed at the low point of the main circuit (≥10 cm below the fuel cell cooling flow channel). When replacing the fuel cell, the controller automatically executes the process of stopping the circulating pump 11, closing solenoid valve 4-12, opening solenoid valve 1-2 and solenoid valve 3-9, reverse purging with 0.2-0.3 bar nitrogen, detecting drainage completion by the flow sensor, and closing the valve. The residual water volume is ≤5 mL, and no manual intervention is required.

[0037] like Figure 1 As shown, the core workflow of this system is divided into the following modes: Normal Operation and Pressure Control Mode: Initiating Fuel Cell Testing. The circulation pump 11 is turned on, and cooling water flows in the main circulation loop. Simultaneously, solenoid valve 2 is opened, and high-pressure nitrogen from nitrogen line 15 is depressurized and precisely regulated by electronic proportional valve 3. The regulated nitrogen is injected into the system (e.g., into the top of the circulating water tank 4), establishing a stable back pressure for the entire cooling water loop. Pressure sensor 8, located on the cooling circulating water inlet line 14, monitors this pressure value in real time and feeds the signal back to the control system. The control system compares this pressure value with a preset target pressure value (set according to the stack gas pressure) and dynamically adjusts the opening of electronic proportional valve 3, forming a closed-loop control loop to ensure that the cooling water pressure is always maintained within a safe range and balanced with the internal gas pressure of the stack.

[0038] Abnormal operating condition safety protection modes: (1) Overpressure protection: If the pressure of the cooling circuit rises abnormally and exceeds the set pressure of the unloading valve 7 due to operational errors or system disturbances, the unloading valve 7 will automatically open to release the overpressure gas / fluid to the outside of the system until the pressure returns to normal and then closes. (2) Power failure safety protection: When the system suddenly loses power, all solenoid valves lose power. At this time, the normally open solenoid valve 25 returns to the open state due to its inherent characteristics, providing a pressure relief channel for the system, automatically releasing pressure, and ensuring the safety of the system under power failure conditions. The circulating pump 11 stops running and the electronic proportional valve 3 closes.

[0039] Replacing the fuel cell stack and purging / draining mode: If the test fuel cell 1 needs to be replaced after the test, follow these steps: a. Stop circulating pump 11.

[0040] b. Close solenoid valve 12 and disconnect cooling circulating water outlet pipeline 13.

[0041] c. Open solenoid valve 12 and solenoid valve 39. Nitrogen gas enters from nitrogen line 15 and is introduced into the system at a lower pressure via electronic proportional valve 3.

[0042] d. Nitrogen flows in the opposite direction along the pipeline, using gas pressure to push the water remaining in the pipeline and the cooling water channel inside the fuel cell stack towards and finally discharge it from the system through the low-positioned solenoid valve 39.

[0043] e. Observe the outlet of solenoid valve 39. After no liquid water is discharged, close solenoid valve 12 and solenoid valve 39. At this time, there is no water accumulation in the system pipeline and fuel cell stack, and the fuel cell stack can be safely disassembled and replaced.

[0044] Throughout the process, the hydrogen concentration sensor 6 continuously monitors the environment, providing additional safety assurance. Example

[0045] This embodiment provides a fuel cell testing system, including an automatic control system for cooling circulating water pressure for fuel cell testing as described in any one of the embodiments.

[0046] As shown in Embodiment 1, the control system includes a cooling circulation main loop, a pressure acquisition device, a controller, a gas source, and a pressure regulating device, which are used to provide precisely controlled cooling circulating water for the fuel cell 1 under test.

[0047] In this testing system, the controller is not only responsible for cooling water pressure control, but also serves as the main controller of the entire testing system, working in coordination with various subsystems to meet various testing needs from steady-state testing to dynamic operating condition simulation. Example

[0048] like Figure 2As shown, this embodiment provides an automatic control method for cooling circulating water pressure in fuel cell testing. Based on the cooling circulating water pressure control system for fuel cell testing described in Embodiment 1, the method uses a controller as the execution entity and includes the following steps: Receive the cooling water pressure signal in the main cooling loop, which is collected in real time by the pressure acquisition device; The received real-time pressure signal is compared with the preset target pressure value to generate an adjustment command; The adjustment command is sent to the pressure regulating device to control the pressure regulating device to adjust the amount of gas injected into the main cooling loop, thereby dynamically adjusting the cooling water pressure. Repeat the above steps to stabilize the cooling water pressure within the allowable error range of the target pressure value.

[0049] It is understood that the automatic control method for cooling circulating water pressure for fuel cell testing in this embodiment is based on the control system in Embodiment 1.

[0050] Normal test pressure control procedure: Start the test system, run the circulating pump 11, and cool water flows in the main loop; pressure sensor 8 collects the water pressure signal of the infeed pipeline in real time and transmits it to the PLC controller; the PLC compares the real-time water pressure with the target pressure, calculates the adjustment amount through the PID algorithm, and sends a command to the electronic proportional valve 3; the electronic proportional valve 3 adjusts the nitrogen injection amount, changes the cooling water back pressure, and achieves pressure balance; pressure sensor 8 continuously feeds back the signal, and the PLC dynamically calibrates and adjusts to maintain the pressure stable within the range of ±0.05 bar.

[0051] Operating condition fluctuation response process: When the fuel cell load changes abruptly, causing a change in gas pressure, pressure sensor 8 captures the water pressure deviation, and the PLC completes the adjustment of the opening of electronic proportional valve 3 within 3 seconds to achieve synchronous pressure balance.

[0052] Emergency troubleshooting procedures: Overpressure: Unloading valve 7 automatically releases pressure, PLC cuts off nitrogen supply and alarms; Power failure: Solenoid valve 2 5 opens to release pressure, circulating pump 11 stops; Leakage: Hydrogen concentration sensor 6 triggers interlock action, quickly releases pressure and cuts off gas supply.

[0053] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0054] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A cooling circulating water pressure control system for fuel cell testing, comprising a cooling circulating main loop, wherein the cooling circulating main loop includes a circulating water tank (4), a circulating pump (11), a heat exchanger (10), and a cooling channel of the fuel cell under test (1) connected sequentially by pipelines, characterized in that, Also includes: A pressure acquisition device is installed on the main cooling loop to acquire cooling water pressure signals; The controller is electrically connected to the pressure acquisition device, receives the pressure signal, compares and calculates it with a preset target pressure value, and outputs an adjustment command. Gas source; The pressure regulating device has its inlet connected to the gas source, its outlet connected to the main cooling cycle circuit, and its control terminal electrically connected to the controller. The pressure regulating device adjusts the amount of gas injected into the main cooling cycle circuit according to the regulating command, so as to dynamically adjust the cooling water pressure.

2. The cooling circulating water pressure control system for fuel cell testing according to claim 1, characterized in that, The pressure acquisition device is installed on the pipeline on the inlet side of the cooling channel.

3. The cooling circulating water pressure control system for fuel cell testing according to claim 1, characterized in that, The outlet of the pressure regulating device is connected to the pipeline on the inlet side of the circulating pump (11).

4. The cooling circulating water pressure control system for fuel cell testing according to claim 1, characterized in that, The controller is a programmable logic controller with a built-in PID control algorithm, which is used to calculate the adjustment command in real time based on the deviation between the pressure signal and the target pressure value.

5. The cooling circulating water pressure control system for fuel cell testing according to claim 1, characterized in that, It also includes a safety interlocking unit, which comprises: A pressure relief device is installed on the main cooling loop to automatically open and relieve pressure when the system pressure exceeds a preset threshold. An emergency pressure relief valve is provided on the circulating water tank (4) and electrically connected to the controller. It is used to automatically open when the controller's pressure relief command is received or when the system is powered off, so as to reduce the system pressure.

6. The cooling circulating water pressure control system for fuel cell testing according to claim 5, characterized in that, The control system further includes: A first switching valve is disposed between the gas source and the pressure regulating device, and the control terminal of the first switching valve is electrically connected to the controller. The safety interlock unit further includes: a gas leak sensor, which is installed on the circulating water tank (4) and electrically connected to the controller, for detecting the concentration of leaked combustible gas; The controller is configured to, in response to the gas leak sensor detecting a concentration exceeding a preset threshold, perform an interlocking action of closing the first switching valve, opening the emergency pressure relief valve, and triggering an alarm.

7. The cooling circulating water pressure control system for fuel cell testing according to claim 1, characterized in that, It also includes a purge and drainage unit, which comprises: A drain valve is installed at the low-level drain port of the main cooling cycle circuit; An isolation valve is installed on the pipeline on the outlet side of the cooling channel; The controller is electrically connected to the drain valve and the isolation valve, and is configured to, upon receiving a drain command, sequentially execute the following actions: stop the circulating pump (11), close the isolation valve, control the pressure regulating device to inject gas into the cooling circulation main circuit to purge and drain the cooling channel, and close the drain valve after the drain is completed.

8. The cooling circulating water pressure control system for fuel cell testing according to claim 7, characterized in that, The purging and drainage unit also includes a flow monitoring module, which is located on the outlet side of the drain valve and electrically connected to the controller, for detecting the drainage status.

9. A fuel cell testing system, characterized in that, Includes the automatic cooling water pressure control system for fuel cell testing as described in any one of claims 1 to 8.

10. An automatic control method for cooling circulating water pressure in fuel cell testing, based on the cooling circulating water pressure control system for fuel cell testing as described in claim 1, wherein the controller is the execution subject, characterized in that, Includes the following steps: Receive the cooling water pressure signal in the main cooling loop, which is collected in real time by the pressure acquisition device; The received real-time pressure signal is compared with the preset target pressure value to generate an adjustment command; The adjustment command is sent to the pressure regulating device to control the pressure regulating device to adjust the amount of gas injected into the main cooling loop, thereby dynamically adjusting the cooling water pressure. Repeat the above steps to stabilize the cooling water pressure within the allowable error range of the target pressure value.

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