Fuel cell stack thermal management method and device for high-power test board

Abstract

The invention relates to the technical field of fuel cell testing, in particular to a fuel cell stack thermal management method and device for a high-power testboard, and the method employs a mode that two thermal management subsystems are connected in parallel, cooperates with a three-way valve, and automatically controls and adjusts the opening degree of each valve according to different working powers of a fuel cell stack and a self-adaptive algorithm. The three-way valve properly distributes the flow of cold water and hot water by adjusting the opening degree, the temperature of the cold water is achieved by conducting heat exchange with external cooling water through the plate heat exchanger, and accurate temperature adjustment is achieved by controlling the opening degree of the pneumatic adjusting valve to adjust the flow of the external cooling water. The high-power excellent thermal management of the fuel cell stack can be realized, meanwhile, the accuracy and stability of temperature control during low-power operation of the fuel cell stack are considered, an excellent temperature control effect in a wide power range is realized, and compared with a series connection mode, the mode of connecting the two thermal management subsystems in parallel can reduce the flow resistance and improve the temperature control efficiency. And the flow resistance of cooling water is reduced.

Description

Technical Field

[0001] The present application relates to the field of fuel cell testing technology, and in particular to a fuel cell stack thermal management method and device for a high-power test bench. Background Art

[0002] In recent years, hydrogen fuel cell technology has developed rapidly. The power of hydrogen fuel cell stacks and fuel cell engines has become increasingly powerful. Fuel cell stacks and fuel cell engines with a capacity of more than 200kW have appeared on the market. At the same time, with the advancement of the application of fuel cell technology in vehicles, ships, aviation, distributed power generation, etc., the power of fuel cell stacks and fuel cell engines will increase further.

[0003] With the development of high-power fuel cell stacks and fuel cell engines, new requirements have been put forward for the test equipment of high-power fuel cell stacks and fuel cell engines. At present, there are literatures mentioning the implementation methods of 300kW and 400kW fuel cell stack test equipment, but it is difficult to find test equipment for fuel cell stacks and fuel cell engines of 500kW and above. Since the working efficiency of fuel cells is about 50%, a large amount of heat is generated during operation and needs to be released in time. The problem is that it is difficult to achieve fast and accurate thermal management for the test equipment of ultra-high-power fuel cell stacks and fuel cell engines above 500kW. Summary of the invention

[0004] The main purpose of this application is to provide a high-power test bench fuel cell stack thermal management method and device, which is suitable for ultra-high-power fuel cell engines and fuel cell stack testing equipment. The present invention can meet the ultra-high power of the test bench fuel cell stack, while taking into account the water thermal management of the fuel cell stack when it is running at low power, to ensure that the ultra-high power fuel cell stack can achieve excellent temperature control effect during full-operating condition testing and verification.

[0005] To achieve the above objectives, this application provides the following technical solutions: According to a first aspect of the present invention, the present invention claims protection for a fuel cell stack thermal management device for a high-power test bench, comprising a first thermal management subsystem, a second thermal management subsystem, a three-way valve, a liquid replenishment and exhaust system, and a fuel cell stack state monitoring system; The first thermal management subsystem includes a first water supply branch, a first water return branch, a first plate heat exchanger, a first temperature sensor, a second temperature sensor, a third temperature sensor, a first pneumatic regulating valve and a first turbine flow meter; The second thermal management subsystem includes a second water supply branch, a second water return branch, a second plate heat exchanger, a fourth temperature sensor, a fifth temperature sensor, a sixth temperature sensor, a second pneumatic regulating valve and a second turbine flow meter; The input ends of the first thermal management subsystem and the second thermal management subsystem are externally connected to a cooling water main supply pipeline, and the output ends of the first thermal management subsystem and the second thermal management subsystem are externally connected to a cooling water return pipeline; The cold side valve port of the three-way valve is connected to the output of the first thermal management subsystem and / or the second thermal management subsystem, the water supply pipe valve port is connected to the water supply end of the device, and the hot side valve port is connected to the return water end of the fuel cell stack state monitoring system; The cold side valve port is connected to a seventh temperature sensor.

[0006] Furthermore, the device also includes: The input end of the fuel cell stack state monitoring system includes a first conductivity sensor, an eighth temperature sensor, a first pressure sensor, and a third manual ball valve; The output end of the fuel cell stack state monitoring system includes a fourth manual ball valve, a second pressure sensor, a ninth temperature sensor, and a third turbine flow meter; The liquid replenishment and exhaust system is connected between the output end of the fuel cell stack state monitoring system and the third valve port.

[0007] Furthermore, the device also includes: The liquid replenishment and exhaust system comprises a fifth manual ball valve, a second filter, a first solenoid valve, a second solenoid valve, a floor drain, a first exhaust hole, a first throttle valve, a transparent rubber hose and a water tank.

[0008] According to a second aspect of the present invention, the present invention claims protection for a fuel cell stack thermal management method for a high-power test bench, which is applied to a fuel cell stack thermal management device for a high-power test bench, comprising: Cold start the fuel cell stack or fuel cell engine at normal temperature idle speed to obtain the optimal operating temperature of the fuel cell stack, and according to the temperature value of the ninth temperature sensor, the cold side valve port of the three-way valve is fully closed, and the thermal measurement valve port is fully opened to control the outlet temperature of the fuel cell stack to reach the optimal operating temperature; Real-time monitoring of the coolant temperature, outlet water pressure and coolant flow of the fuel cell stack; When the coolant temperature value of the fuel cell stack exceeds the optimal operating temperature of the fuel cell stack, the opening of the three-way valve, the opening of the first pneumatic regulating valve and / or the second pneumatic regulating valve are adjusted according to the operating power segment of the fuel cell stack, and part or all of the external cooling water is heat exchanged with the coolant through the first thermal management subsystem and / or the second thermal management subsystem.

[0009] Further, the fuel cell stack or fuel cell engine is cold started at normal temperature idle speed to obtain the optimal operating temperature of the fuel cell stack, and according to the temperature value of the ninth temperature sensor, the cold side valve port of the three-way valve is fully closed, the thermal measurement valve port is fully opened, and the outlet temperature of the fuel cell stack is controlled to reach the optimal operating temperature, and further includes: When the fuel cell stack or the fuel cell engine is cold started at normal temperature and idle speed, under normal temperature environment, the coolant temperature is the temperature value of the ninth temperature sensor, and the optimal operating temperature of the proton exchange membrane fuel cell stack is greater than the coolant temperature; Raising the temperature of the coolant from the coolant temperature to a set optimal operating temperature by using the heat released during the operation of the fuel cell stack; At this time, the cold side valve port of the three-way valve is fully closed, and the hot side valve port is fully open.

[0010] Furthermore, real-time monitoring of the coolant temperature value, outlet water pressure value and coolant flow value of the fuel cell stack also includes: Real-time monitoring of the temperature value of the eighth temperature sensor of the fuel cell stack, the water inlet pressure value of the first pressure sensor, the temperature value of the ninth temperature sensor of the fuel cell stack, the water outlet pressure value of the second pressure sensor, the coolant conductivity of the first conductivity sensor, and the coolant flow value of the third turbine flowmeter.

[0011] Further, when the temperature value of the coolant of the fuel cell stack exceeds the optimal operating temperature of the fuel cell stack, the opening of the three-way valve, the opening of the first pneumatic regulating valve and / or the second pneumatic regulating valve are adjusted according to the operating power segment of the fuel cell stack, and part or all of the external cooling water is heat exchanged with the coolant through the first thermal management subsystem and / or the second thermal management subsystem, and further comprising: When the operating power stage of the fuel cell stack is a low power stage or a medium power stage, starting one of the first thermal management subsystem or the second thermal management subsystem and matching and adjusting the opening of the three-way valve; The opening of the first pneumatic regulating valve or the second pneumatic regulating valve and the three-way valve is solved in real time by an adaptive algorithm, so that the input temperature value of the fuel cell stack does not differ from the optimal operating temperature by more than a first threshold.

[0012] Furthermore, the method further comprises: When the operating power section of the fuel cell stack is a high power section and the corresponding pneumatic regulating valve in the first thermal management subsystem or the second thermal management subsystem reaches the upper limit of the heat dissipation capacity, the other thermal management subsystem in the first thermal management subsystem or the second thermal management subsystem is turned on; The power of the fuel cell stack continues to increase, following the coordination of adjusting the first pneumatic regulating valve, the second pneumatic regulating valve, and the three-way valve; The first pneumatic regulating valve and the second pneumatic regulating valve cooperate to achieve the cooling temperature target value under the opening state of the three-way valve.

[0013] Furthermore, the method of solving the opening of the first pneumatic regulating valve or the second pneumatic regulating valve and the three-way valve in real time by using an adaptive algorithm so that the input temperature value of the fuel cell stack does not differ from the optimal operating temperature by more than a first threshold value also includes: When the opening of the three-way valve is kept constant, the opening of the cold side valve port of the three-way valve is kept at the value before the transient load, and the relative percentage of the cold water and hot water flow through the three-way valve remains unchanged, that is, the external cooling water amount of the fuel cell stack participating in the external heat exchange remains unchanged; The temperature of the valve port side of the cold side of the three-way valve is lowered to release excess heat. The opening of the first pneumatic regulating valve is automatically and timely increased to obtain the optimal solution of the opening of the first pneumatic regulating valve in real time, thereby increasing the heat exchange between the coolant and the external cooling water, reducing the coolant temperature, and realizing temperature control during transient loading.

[0014] Furthermore, the method further comprises: When the temperature control in the transient loading process is difficult to reach the target, the cold side valve opening of the three-way valve is automatically adjusted to redistribute the relative percentages of the cold and hot water flows; Calculating a temperature adjustment target value of the first thermal management subsystem or the second thermal management subsystem based on the new cold-side valve port of the three-way valve; The opening of the first pneumatic regulating valve or the second pneumatic regulating valve is adjusted to ensure that the difference between the temperature of the cold-side valve port of the three-way valve and the temperature adjustment target value is not greater than a second threshold.

[0015] The present application relates to the field of fuel cell testing technology, and in particular to a method and device for thermal management of a fuel cell stack for a high-power test bench. The method and device adopt a parallel connection of two thermal management subsystems, cooperate with a three-way valve, and automatically control and adjust the opening of each valve according to the different working powers of the fuel cell stack according to an adaptive algorithm. The three-way valve is adjusted by opening to properly distribute the flow of cold water and hot water. The temperature of the cold water is achieved by heat exchange with external cooling water through a plate heat exchanger. The precise adjustment of the temperature is achieved by controlling the opening of a pneumatic regulating valve to adjust the flow of external cooling water. The present invention can achieve excellent thermal management of the fuel cell stack at high power while taking into account the accuracy and stability of temperature control when the fuel cell stack is running at low power, and achieve excellent temperature control effect in a wide power range. Compared with the series connection method, the parallel connection of the two thermal management subsystems can reduce the flow resistance and reduce the flow resistance of the cooling water. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1A structural diagram of a fuel cell stack thermal management device for a high-power test bench as claimed in an embodiment of the present application; Figure 2 A second structural diagram of a fuel cell stack thermal management device for a high-power test bench as claimed in an embodiment of the present application; Figure 3 A schematic diagram of a liquid replenishment and exhaust device for a fuel cell stack thermal management device for a high-power test bench as claimed in an embodiment of the present application; Figure 4 A structural diagram of a water supply and return circuit of a fuel cell stack thermal management device for a high-power test bench claimed in an embodiment of the present application; Figure 5 A flowchart of a fuel cell stack thermal management method for a high-power test bench as claimed in an embodiment of the present application; Figure 6 A schematic diagram of an equal percentage flow curve of a thermal management method for a fuel cell stack for a high-power test bench claimed in an embodiment of the present application; Figure 7 A transient loading schematic diagram of a thermal management method for a fuel cell stack for a high-power test bench as claimed in an embodiment of the present application; Figure 8 A schematic diagram of transient load reduction of a thermal management method for a fuel cell stack for a high-power test bench as claimed in an embodiment of the present application. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0018] The terms "first", "second" and "third" in this application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" and "third" can explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. All directional indications (such as up, down, left, right, front, back...) in the embodiments of this application are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0019] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0020] According to a first embodiment of the present invention, the present invention claims protection for a fuel cell stack thermal management device for a high-power test bench, comprising a first thermal management subsystem, a second thermal management subsystem, a three-way valve, a liquid replenishment and exhaust system, and a fuel cell stack state monitoring system; The first thermal management subsystem includes a first water supply branch, a first water return branch, a first plate heat exchanger, a first temperature sensor, a second temperature sensor, a third temperature sensor, a first pneumatic regulating valve and a first turbine flow meter; The second thermal management subsystem includes a second water supply branch, a second water return branch, a second plate heat exchanger, a fourth temperature sensor, a fifth temperature sensor, a sixth temperature sensor, a second pneumatic regulating valve and a second turbine flow meter; The input ends of the first thermal management subsystem and the second thermal management subsystem are externally connected to a cooling water main supply pipeline, and the output ends of the first thermal management subsystem and the second thermal management subsystem are externally connected to a cooling water return pipeline; The cold side valve port of the three-way valve is connected to the output of the first thermal management subsystem and / or the second thermal management subsystem, the water supply pipe valve port is connected to the input end of the fuel cell stack test system, and the hot side valve port is connected to the output end of the fuel cell stack test system; The cold side valve port is connected to a seventh temperature sensor.

[0021] Furthermore, the device also includes: The input end of the fuel cell stack state monitoring system includes a first conductivity sensor, an eighth temperature sensor, a first pressure sensor, and a third manual ball valve; The output end of the fuel cell stack state monitoring system includes a fourth manual ball valve, a second pressure sensor, a ninth temperature sensor, and a third turbine flow meter; The liquid replenishment and exhaust system is connected between the output end of the fuel cell stack state monitoring system and the third valve port.

[0022] Furthermore, the device also includes: The liquid replenishment and exhaust system comprises a fifth manual ball valve, a second filter, a first solenoid valve, a second solenoid valve, a floor drain, a first exhaust hole, a first throttle valve, a transparent rubber hose and a water tank.

[0023] In this embodiment, reference is made to Figure 1 and 2 , a structural diagram of a fuel cell generator and a fuel cell stack thermal management device for a high-power test bench of this embodiment; T1: monitoring value of temperature sensor 1; T2: monitoring value of temperature sensor 2; T3: monitoring value of temperature sensor 3; T4: monitoring value of temperature sensor 4; T5: monitoring value of temperature sensor 5; T6: monitoring value of temperature sensor 6; T7: monitoring value of temperature sensor 7; T8: monitoring value of temperature sensor 8; T9: monitoring value of temperature sensor 9; Cc: Monitoring value of conductivity sensor 1 P1: monitoring value of pressure sensor 1; P2: monitoring value of pressure sensor 2; F1: monitoring value of turbine flowmeter 1; F2: monitoring value of turbine flowmeter 2; F3: monitoring value of turbine flowmeter 3; c: specific heat capacity of cooling water; T 设 : The set temperature of the fuel cell engine main diffuser (fuel cell stack) inlet, that is, the target temperature of the cooling water; m 冷: The flow rate of cooling water at the outlet of the fuel cell stack that passes through the thermal management subsystem (subsystem 1 and / or subsystem 2) for heat exchange with the outside world (unit: L / min); m 热 : The water flow mass of the cooling water at the outlet of the fuel cell stack that does not pass through the thermal management subsystem, that is, the part that flows out from the outlet of the fuel cell stack and directly circulates to the inlet of the fuel cell stack through the three-way valve 1 (unit: L / min); m 总 : The total flow rate in the fuel cell stack cooling cycle (unit: L / min, i.e. the value monitored by the turbine flowmeter F3); m 外界冷却水 : The flow rate of external cooling water passing through the plate heat exchanger (Note: generally the mass per unit time (min)); φ 冷 : Opening degree of three-way valve 1 on the cold side; φ 热 : Opening degree of hot side of three-way valve 1, where φcold+φhot=100%; φ1: opening of pneumatic control valve 1; φ2: opening of pneumatic control valve 2; During operation, the conductivity sensor is used to monitor C in real time. c , to avoid electrical safety problems caused by increased conductivity and decreased insulation of cooling water.

[0024] Thermal management subsystem 1 is equipped with turbine flowmeter 1, thermal management subsystem 2 is equipped with turbine flowmeter 2, and the main cooling water circuit is equipped with turbine flowmeter 3. For the convenience of monitoring, the flow allocated to thermal management subsystem 1 and thermal management subsystem 2 is designed according to equal flow resistance to achieve a flow distribution effect of 50%:50%. However, in actual application, due to various factors, the flow distribution of the two thermal management subsystems may be uneven, affecting the opening adjustment of pneumatic control valve 1 and pneumatic control valve 2. Therefore, the flow is monitored in real time, and the heat dissipation borne by each can be further calculated to achieve independent control of the two thermal management subsystems.

[0025] The outlet of the plate heat exchanger of each thermal management subsystem is equipped with a temperature sensor, namely, temperature sensor 3 Furthermore, the two thermal management subsystems can also adjust the temperature according to the "synchronous" control method. That is, regardless of the low, medium and high power ranges, the thermal management subsystem 1 and the thermal management subsystem 2 each bear 50% of the heat dissipation demand, that is, the opening of the pneumatic control valve 1 and the pneumatic control valve 2 are adjusted synchronously.

[0026] The above is a method of connecting two thermal management subsystems in parallel. The maximum upper limit can meet the heat dissipation requirements of an 800kW fuel cell engine (1000kW, i.e., 1MW fuel cell stack). The thermal management subsystems can be further connected in parallel, and more thermal management subsystems can be connected in parallel to meet the heat dissipation requirements of higher-power fuel cell engines (fuel cell stacks) during testing.

[0027] A single thermal management subsystem (1 or 2) can be used as a thermal management system for a 200kW or 300kW test device, with strong downward and upward compatibility.

[0028] The thermal management system during the testing of medium and low power fuel cell engines (fuel cell stacks) can also adopt the above-mentioned multiple thermal management subsystems in parallel to achieve higher precision temperature control.

[0029] Figure 3 It is a replenishment and exhaust device for the thermal management system. Deionized water (or special coolant for fuel cell stack) is injected into the thermal management system as needed. The manual ball valve 5 can be used to manually control the opening and closing of the water replenishment. The filter 2 filters it to prevent impurities from entering the system. The solenoid valve 1 can be automatically opened according to the liquid level to perform the water replenishment operation. There are 3 liquid level switches on the water tank to facilitate real-time monitoring of the water tank level. The liquid level switch 1 is used for high liquid level monitoring. When the liquid level is higher than this point, the solenoid valve 2 is automatically opened to drain the excess water to the floor drain (or designated location). When the liquid level switch 2 is used for low liquid level monitoring, when the liquid level is lower than this point, the solenoid valve 1 is automatically opened for water replenishment. The liquid level switch 3 is used for alarm prompts. When the liquid level is detected at this point, the operator is warned to observe whether the water tank status is abnormal.

[0030] The water tank injects water into the pipes in the thermal management system through the water supply pipe 1. The thermal management system exhausts the pipes through the exhaust pipe 1. The throttle valve 1 can be adjusted to adjust the water flow accompanying the exhaust. The transparent hose 1 facilitates the observation of the exhaust effect.

[0031] An exhaust hole 1 is provided on the water tank through a pipe extending outward, and a dustproof joint is installed on the exhaust hole 1 to prevent foreign matter such as dust from entering the water tank.

[0032] Reference Figure 4 The manual ball valve 1 in the water supply and return circuit manually controls the opening and closing of the cooling water supply. The filter 1 filters the impurity particles such as rust in the external cooling water to prevent the impurity particles from entering the thermal management system and causing adverse consequences such as blockage of the plate heat exchanger. The filter 1 is connected to the main water supply pipeline, and the main water supply pipeline extends into two branches, namely the water supply branch 1 and the water supply branch 2. Generally, the main water supply pipeline has a larger diameter than the water supply branch. The return branch 1 and the return branch 2 converge into the main return water pipeline. Generally, the main return water pipeline has a larger diameter than the return water branch. The manual ball valve 2 can manually control the opening and closing of the cooling water return.

[0033] According to the second embodiment of the present invention, the present invention claims a method for thermal management of a fuel cell stack for a high-power test bench, which is applied to a thermal management device for a fuel cell stack for a high-power test bench, referring to Figure 5 ,include: Cold start the fuel cell stack or fuel cell engine at normal temperature idle speed to obtain the optimal operating temperature of the fuel cell stack, and according to the temperature value of the ninth temperature sensor, the cold side valve port of the three-way valve is fully closed, and the thermal measurement valve port is fully opened to control the outlet temperature of the fuel cell stack to reach the optimal operating temperature; Real-time monitoring of the coolant temperature, outlet water pressure and coolant flow of the fuel cell stack; When the coolant temperature value of the fuel cell stack exceeds the optimal operating temperature of the fuel cell stack, the opening of the three-way valve, the opening of the first pneumatic regulating valve and / or the second pneumatic regulating valve are adjusted according to the operating power segment of the fuel cell stack, and part or all of the external cooling water is heat exchanged with the coolant through the first thermal management subsystem and / or the second thermal management subsystem.

[0034] Further, the fuel cell stack or fuel cell engine is cold started at normal temperature idle speed to obtain the optimal operating temperature of the fuel cell stack, and according to the temperature value of the ninth temperature sensor, the cold side valve port of the three-way valve is fully closed, the thermal measurement valve port is fully opened, and the outlet temperature of the fuel cell stack is controlled to reach the optimal operating temperature, and further includes: When the fuel cell stack or the fuel cell engine is cold started at normal temperature and idle speed, under normal temperature environment, the coolant temperature is the temperature value of the ninth temperature sensor, and the optimal operating temperature of the proton exchange membrane fuel cell stack is greater than the coolant temperature; Raising the temperature of the coolant from the coolant temperature to a set optimal operating temperature by using the heat released during the operation of the fuel cell stack; At this time, the cold side valve port of the three-way valve is fully closed, and the hot side valve port is fully open.

[0035] In this embodiment, when the fuel cell engine (fuel cell stack) is cold started at normal temperature idle speed, under normal temperature environment, the coolant T9 (the temperature T9 monitored by the fuel cell stack outlet temperature sensor 9) is 25°C, and the optimal operating temperature of the proton exchange membrane fuel cell stack is usually 60~80°C (the target setting temperature T 设 ), therefore, under this condition, when T9<T 设 When the fuel cell stack is running, the heat released by the fuel cell stack during operation is used to quickly raise the coolant temperature from 25°C to the set temperature T. 设 (60~80℃). At this time, the cold side of the three-way valve is fully closed, and the hot side is fully open, that is, φ 冷 =0%,φ热 =100%.

[0036] Furthermore, real-time monitoring of the coolant temperature value, outlet water pressure value and coolant flow value of the fuel cell stack also includes: Real-time monitoring of the temperature value of the eighth temperature sensor of the fuel cell stack, the water inlet pressure value of the first pressure sensor, the temperature value of the ninth temperature sensor of the fuel cell stack, the water outlet pressure value of the second pressure sensor, the coolant conductivity of the first conductivity sensor, and the coolant flow value of the third turbine flowmeter.

[0037] Further, when the temperature value of the coolant of the fuel cell stack exceeds the optimal operating temperature of the fuel cell stack, the opening of the three-way valve, the opening of the first pneumatic regulating valve and / or the second pneumatic regulating valve are adjusted according to the operating power segment of the fuel cell stack, and part or all of the external cooling water is heat exchanged with the coolant through the first thermal management subsystem and / or the second thermal management subsystem, and further comprising: When the operating power stage of the fuel cell stack is a low power stage or a medium power stage, starting one of the first thermal management subsystem or the second thermal management subsystem and matching and adjusting the opening of the three-way valve; The opening of the first pneumatic regulating valve or the second pneumatic regulating valve and the three-way valve is solved in real time by an adaptive algorithm, so that the input temperature value of the fuel cell stack does not differ from the optimal operating temperature by more than a first threshold.

[0038] In this embodiment, T9>T 设 When the fuel cell engine (fuel cell stack) is running in the low and medium power range, the heat generated by the fuel cell stack is relatively small. In order to maintain the operating temperature of the fuel cell stack, the heat exchange between the thermal management system and the outside world is small. At this time, only one thermal management subsystem is required to participate in thermal management to achieve the temperature control effect. That is, thermal management subsystem 1 (or subsystem 2) operates alone, and the opening of three-way valve 1 is matched and adjusted at the same time. The opening of pneumatic control valve 1 (or pneumatic control valve 2) and three-way valve 1 are solved in real time through the adaptive algorithm to ensure T8=T 设 ±δ, δ≤3℃. When the opening of the three-way valve is kept constant, the opening of the cold side valve port of the three-way valve is kept at the value before the transient load, and the relative percentage of the cold water and hot water flow through the three-way valve remains unchanged, that is, the external cooling water volume of the fuel cell stack participating in the external heat exchange remains unchanged; The temperature of the valve port side of the cold side of the three-way valve is lowered to release excess heat. By automatically and timely increasing the opening of the first pneumatic regulating valve or the second regulating valve, the optimal solution for the opening of the first pneumatic regulating valve or the second regulating valve is sought in real time, the heat exchange between the coolant and the external cooling water is increased, the coolant temperature is lowered, and temperature control during transient loading is achieved.

[0039] In this embodiment, the opening of the three-way valve is kept constant, that is, φ 冷 Keep the value before transient loading (φ 冷 ≠0), the relative percentage of the cold water and hot water flow through the three-way valve remains unchanged, that is, the amount of cooling water of the fuel cell stack participating in the external heat exchange remains unchanged, and the excess heat is released by lowering the cold water temperature T7. That is, by automatically and timely increasing the opening of the first pneumatic regulating valve or the second pneumatic regulating valve, the optimal solution of the opening of the first pneumatic regulating valve or the second pneumatic regulating valve is sought in real time, the heat exchange between the cooling water and the external cold water is increased, thereby lowering the cold water temperature T9, and realizing temperature control during transient loading.

[0040] Furthermore, the method further comprises: When the opening of the three-way valve is kept constant and it is difficult to achieve the target, the opening of the cold side valve port of the three-way valve is automatically adjusted to redistribute the relative percentages of the cold and hot water flows; Calculating a temperature adjustment target value of the first thermal management subsystem or the second thermal management subsystem based on the new cold-side valve port of the three-way valve; The opening of the first pneumatic regulating valve or the second regulating valve is adjusted to ensure that the difference between the temperature of the cold-side valve port of the three-way valve and the temperature adjustment target value is not greater than a second threshold.

[0041] That is, the opening of the three-way valve 1 is automatically adjusted in time to redistribute the relative percentage of the cold and hot water flows. 冷 Calculate T 冷 , with T 冷 As the temperature adjustment target value of the first thermal management subsystem (or the second thermal management subsystem), T7 is the measured feedback value. By adjusting the opening of the first pneumatic control valve (or the second pneumatic control valve 2), T7 = T 冷 ±δ1,δ1≤1℃.

[0042] The specific process is as follows: φ 冷 =m 冷 / m 总 According to cm 冷 (T 热 -T 冷 )=cm 总 (T 热 -T 设 )get

[0043] The cold water opening of the three-way valve is obtained from this 冷 With T 冷 Relationship, when adjusting the temperature, according to the current φ 冷 The value of T is automatically calculated冷 , T 冷 That is, the temperature control target of the thermal management subsystem, and T7 is the feedback value during the adjustment process.

[0044] According to cm 冷 (T 热 -T 冷 )=cm 外界冷却水 (T2-T1), where the first pneumatic control valve opening φ1 (the second pneumatic control valve opening φ2) and m 外界冷却水 The relationship curve (equal percentage flow curve) is as follows Figure 6 As shown; Thus, φ1 (φ2) and m are established. 外界冷却水 relationship, that is, without monitoring m 外界冷却水 The temperature control can be adjusted. Furthermore, T2 and T1 can be ignored and T can be completely controlled by PID. 冷 Furthermore, real-time monitoring is installed 外界冷却水 The turbine flowmeter can further improve the temperature control accuracy.

[0045] The opening of the first pneumatic control valve φ1 (or the opening of the second pneumatic control valve φ2) is automatically adjusted by PID to make T7=T 冷 Finally, the cold and hot water are mixed through the three-way valve, and the temperature of the mixed cooling water is T 设 , to achieve precise control of target temperature.

[0046] In summary, the entire temperature control process is essentially 冷 and φ1 (or φ2) in real-time dynamic search for the optimal solution.

[0047] When the fuel cell engine (fuel cell stack) is running in a steady state (i.e., running at a fixed power point), the heat generated by the fuel cell stack is almost stable at a value with little fluctuation. 冷 After obtaining the optimal solution of φ1, it is only necessary to maintain the optimal solution of the opening and perform PID fine-tuning on the accompanying temperature fluctuations to achieve the ideal effect.

[0048] Reference Figure 7 and 8 When the fuel cell engine (fuel cell stack) is in transient operation (i.e., it is instantly loaded from a low power point to a high power point, or instantly reduced from a high power point to a low power point), the operating power of the fuel cell stack changes suddenly. At this time, φ 冷 When φ1 is adjusted, it also quickly follows the adjustment to quickly achieve a surge or sharp decrease in heat dissipation. After the fuel cell stack is stable, φ 冷 and φ1 are also fine-tuned up and down around the stable value (optimal solution).

[0049] Furthermore, the method further comprises: When the operating power section of the fuel cell stack is a high power section and the corresponding pneumatic regulating valve in the first thermal management subsystem or the second thermal management subsystem reaches the upper limit of the heat dissipation capacity, the other thermal management subsystem in the first thermal management subsystem or the second thermal management subsystem is turned on; The power of the fuel cell stack continues to increase, following the coordination of adjusting the first pneumatic regulating valve, the second pneumatic regulating valve, and the three-way valve; The first pneumatic regulating valve and the second pneumatic regulating valve cooperate to achieve the cooling temperature target value under the opening state of the three-way valve.

[0050] In this embodiment, when the fuel cell engine (fuel cell stack) is running in the high power range, the fuel cell stack generates a large amount of heat. To maintain the operating temperature of the fuel cell stack, the two thermal management subsystems need to cooperate to achieve high-power heat dissipation. 冷 When both φ1 and φ2 are at high opening (e.g., 80%), it indicates that the heat dissipation capacity limit of the first thermal management subsystem is approaching. At this time, the second thermal management subsystem is gradually connected, that is, the opening φ2 of the second pneumatic control valve gradually starts from 0, and as the power of the fuel cell stack increases further, it is adjusted in time. That is, the first pneumatic control valve, the second pneumatic control valve, and the three-way valve work together. The first pneumatic control valve and the second pneumatic control valve work together to achieve the three-way valve φ 冷 T in the open state 冷 Target value.

[0051] Furthermore, the openings of the first pneumatic regulating valve, the second pneumatic regulating valve and the three-way valve are solved in real time by the adaptive algorithm, so that the input temperature value of the fuel cell stack does not differ from the optimal operating temperature by more than a first threshold.

[0052] The described is a "one main and one auxiliary" thermal management method for the first and second thermal management subsystems, that is, the first thermal management subsystem is the main one and the second thermal management subsystem is the auxiliary one. When the heat dissipation capacity of the first thermal management subsystem reaches or is about to reach the upper limit of the heat dissipation capacity, the second thermal management subsystem is started. Furthermore, the second thermal management subsystem can also be the main one and the first thermal management subsystem can be the auxiliary one. Furthermore, the temperature of the first and second thermal management subsystems can be adjusted according to the "synchronous" control method. That is, no matter whether the fuel cell stack or the fuel cell engine is operating in the low, medium or high power range, the first thermal management subsystem and the second thermal management subsystem each bear 50%:50% of the heat dissipation demand, that is, the first pneumatic control valve and the second pneumatic control valve are adjusted synchronously.

[0053] The high-power test bench fuel cell stack thermal management method and device can meet the heat dissipation requirements of an 800kW fuel cell engine (1MW fuel cell stack) at the maximum upper limit. Furthermore, the thermal management device can connect more thermal management subsystems in parallel to meet the heat dissipation requirements of a higher-power fuel cell engine (fuel cell stack) test.

[0054] The thermal management method and device for a fuel cell stack for a high-power test bench are also applicable to the thermal management of fuel cell stacks for medium and low-power test benches. This method can achieve higher precision temperature control. In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0055] In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of software functional units. The above is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of this application, or directly or indirectly used in other related technical fields, is also included in the patent protection scope of the present application.

[0056] The specific implementation methods of the invention are described in detail above, but they are only examples, and the present application is not limited to the specific implementation methods described above. For those skilled in the art, any equivalent modification or substitution of the invention is also within the scope of the present application, and therefore, the equalization, modification, and improvement made without departing from the spirit and principle of the present application should be included in the scope of the present application.

Claims

1. A fuel cell stack thermal management device for a high-power test bench, characterized in that: It includes a first thermal management subsystem, a second thermal management subsystem, a three-way valve, a liquid replenishment and exhaust system, and a fuel cell stack test system; The first thermal management subsystem includes a first water supply branch, a first water return branch, a first plate heat exchanger, a first temperature sensor, a second temperature sensor, a third temperature sensor, a first pneumatic regulating valve and a first turbine flow meter; The second thermal management subsystem includes a second water supply branch, a second water return branch, a second plate heat exchanger, a fourth temperature sensor, a fifth temperature sensor, a sixth temperature sensor, a second pneumatic regulating valve and a second turbine flow meter; The input ends of the first thermal management subsystem and the second thermal management subsystem are externally connected to a cooling water main supply pipeline, and the output ends of the first thermal management subsystem and the second thermal management subsystem are externally connected to a cooling water return pipeline; The cold side valve port of the three-way valve is connected to the output of the first thermal management subsystem and / or the second thermal management subsystem, the water supply pipe valve port is connected to the input end of the fuel cell stack state monitoring system, and the hot side valve port is connected to the output end of the fuel cell stack testing system; The cold side valve port is connected to a seventh temperature sensor.

2. A fuel cell stack thermal management device for a high-power test bench as claimed in claim 1, characterized in that: Also includes: The input end of the fuel cell stack test system includes a first conductivity sensor, an eighth temperature sensor, a first pressure sensor, and a third manual ball valve; The output end of the fuel cell stack test system includes a fourth manual ball valve, a second pressure sensor, a ninth temperature sensor, and a third turbine flowmeter; The liquid replenishment and exhaust system is connected between the output end of the fuel cell stack test system and the third valve port.

3. A fuel cell stack thermal management device for a high-power test bench as claimed in claim 1, characterized in that: Also includes: The liquid replenishment and exhaust system comprises a fifth manual ball valve, a second filter, a first solenoid valve, a second solenoid valve, a floor drain, a first exhaust hole, a first throttle valve, a transparent rubber hose and a water tank.

4. A thermal management method for a fuel cell stack for a high-power test bench, applied to a thermal management device for a fuel cell stack for a high-power test bench as claimed in any one of claims 1 to 3, characterized in that: include: Cold start the fuel cell stack or fuel cell engine at normal temperature idle speed to obtain the optimal operating temperature of the fuel cell stack, and according to the temperature value of the ninth temperature sensor, the cold side valve port of the three-way valve is fully closed, and the thermal measurement valve port is fully opened to control the outlet temperature of the fuel cell stack to reach the optimal operating temperature; Real-time monitoring of the coolant temperature, outlet water pressure and coolant flow of the fuel cell stack; When the coolant temperature value of the fuel cell stack exceeds the optimal operating temperature of the fuel cell stack, the opening of the three-way valve, the opening of the first pneumatic regulating valve and / or the second pneumatic regulating valve are adjusted according to the operating power segment of the fuel cell stack, and part or all of the external cooling water is heat exchanged with the coolant through the first thermal management subsystem and / or the second thermal management subsystem.

5. A fuel cell stack thermal management method for a high-power test bench as claimed in claim 4, characterized in that: The method of cold starting the fuel cell stack or fuel cell engine at normal temperature idle speed to obtain the optimal operating temperature of the fuel cell stack, and according to the temperature value of the ninth temperature sensor, the cold side valve port of the three-way valve is fully closed, the thermal measurement valve port is fully opened, and the outlet temperature of the fuel cell stack is controlled to reach the optimal operating temperature, further comprising: When the fuel cell stack or the fuel cell engine is cold started at normal temperature and idle speed, under normal temperature environment, the coolant temperature is the temperature value of the ninth temperature sensor, and the optimal operating temperature of the proton exchange membrane fuel cell stack is greater than the coolant temperature; Raising the temperature of the coolant from the coolant temperature to a set optimal operating temperature by using the heat released during the operation of the fuel cell stack; At this time, the cold side valve port of the three-way valve is fully closed, and the hot side valve port is fully open.

6. A fuel cell stack thermal management method for a high-power test bench as claimed in claim 4, characterized in that: Real-time monitoring of the coolant temperature value, water outlet pressure value and coolant flow value of the fuel cell stack also includes: Real-time monitoring of the temperature value of the eighth temperature sensor of the fuel cell stack, the water inlet pressure value of the first pressure sensor, the temperature value of the ninth temperature sensor of the fuel cell stack, the water outlet pressure value of the second pressure sensor, the coolant conductivity of the first conductivity sensor, and the coolant flow value of the third turbine flowmeter.

7. A fuel cell stack thermal management method for a high-power test bench as claimed in claim 4, characterized in that: When the temperature value of the coolant of the fuel cell stack exceeds the optimal operating temperature of the fuel cell stack, the opening of the three-way valve, the opening of the first pneumatic regulating valve and / or the second pneumatic regulating valve are adjusted according to the operating power segment of the fuel cell stack, and part or all of the external cooling water is heat exchanged with the coolant through the first thermal management subsystem and / or the second thermal management subsystem, and further comprising: When the operating power stage of the fuel cell stack is a low power stage or a medium power stage, starting one of the first thermal management subsystem or the second thermal management subsystem and matching and adjusting the opening of the three-way valve; The opening of the first pneumatic regulating valve or the second pneumatic regulating valve and the three-way valve is solved in real time by an adaptive algorithm, so that the input temperature value of the fuel cell stack does not differ from the optimal operating temperature by more than a first threshold.

8. A fuel cell stack thermal management method for a high-power test bench as claimed in claim 7, characterized in that: Also includes: When the operating power section of the fuel cell stack is a high power section and the corresponding pneumatic regulating valve in the first thermal management subsystem or the second thermal management subsystem reaches the upper limit of the heat dissipation capacity, the other thermal management subsystem in the first thermal management subsystem or the second thermal management subsystem is turned on; The power of the fuel cell stack continues to increase, following the coordination of adjusting the first pneumatic regulating valve, the second pneumatic regulating valve, and the three-way valve; The first pneumatic regulating valve and the second pneumatic regulating valve cooperate to achieve the cooling temperature target value under the opening state of the three-way valve.

9. A fuel cell stack thermal management method for a high-power test bench as claimed in claim 7, characterized in that: The method of solving the opening of the first pneumatic regulating valve or the second pneumatic regulating valve and the three-way valve in real time by using an adaptive algorithm so that the difference between the input temperature value of the fuel cell stack and the optimal operating temperature does not exceed a first threshold value also includes: When the opening of the three-way valve is kept constant, the opening of the cold side valve port of the three-way valve is kept at the value before the transient load, and the relative percentage of the cold water and hot water flow through the three-way valve remains unchanged, that is, the external cooling water amount of the fuel cell stack participating in the external heat exchange remains unchanged; The temperature of the cold-side valve port of the three-way valve is lowered to release excess heat. The opening of the first pneumatic regulating valve is automatically and timely increased to obtain the optimal solution for the opening of the first pneumatic regulating valve in real time, thereby increasing the heat exchange between the coolant and the external cooling water, lowering the coolant temperature, and realizing temperature control during transient loading.

10. A fuel cell stack thermal management method for a high-power test bench as claimed in claim 9, characterized in that: Also includes: When the temperature control during the transient loading process is difficult to reach the target, the cold side valve opening of the three-way valve is automatically adjusted to redistribute the relative percentages of the cold and hot water flows; Calculating a temperature adjustment target value of the first thermal management subsystem or the second thermal management subsystem based on the new cold-side valve port of the three-way valve; The opening of the first pneumatic regulating valve or the second pneumatic regulating valve is adjusted to ensure that the difference between the temperature of the cold-side valve port of the three-way valve and the temperature adjustment target value is not greater than a second threshold.

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