A proportional valve-based fuel cell anode back pressure control system

Abstract

The application relates to a fuel cell anode back pressure control system based on a proportional valve, which comprises a hydrogen conveying pipe, a stack, a hydrogen exhaust pipe, an inlet pressure sensor, an outlet pressure sensor, a hydrogen supply module, a heat dissipation module, a water-vapor separation module and a proportional valve; the hydrogen conveying pipe is connected with a hydrogen inlet of the stack, the inlet pressure sensor is used for detecting hydrogen pressure at the hydrogen inlet of the stack, and the hydrogen supply module is arranged on the hydrogen conveying pipe; the hydrogen exhaust pipe is connected with a hydrogen outlet of the stack, the outlet pressure sensor is used for detecting hydrogen pressure at the hydrogen outlet of the stack, the heat dissipation module, the water-vapor separation module and the proportional valve are sequentially arranged on the hydrogen exhaust pipe, and the proportional valve is connected to a hydrogen tail exhaust. Compared with the prior art, the application combines the heat dissipation module, the water-vapor separation module and the proportional valve to control back pressure of a hydrogen path, has low overall cost, short delivery period, does not need to regularly replace modules, can accurately control anode pressure during fuel cell testing, and has high precision and fast response.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell, in particular to a fuel cell anode back pressure control system based on proportional valve. BACKGROUND

[0002] Fuel cell is an electrochemical device that directly converts stored chemical energy into electrical energy, heat energy and water through chemical reaction. As a new type of green power source, fuel cell engine is gradually becoming one of the research focuses of vehicle-mounted engine due to its excellent characteristics such as high efficiency and low emission. Fuel cell engine is based on the output of load, and has good controllability for the whole vehicle. Meanwhile, the energy output of fuel cell engine is electrical energy, which simplifies the transmission and speed regulation structure of traditional vehicles. Although fuel cell engine has many advantages compared with internal combustion engine, there are still many problems to be solved before fuel cell engine can replace internal combustion engine as the mainstream of vehicle engine.

[0003] In the test of fuel cell engine, the test of fuel cell stack, the core component of fuel cell engine, has great problems. The back pressure control of fuel cell stack test is generally realized by diaphragm back pressure valve. However, at present, diaphragm back pressure valve is more dependent on import and needs to be matched with corresponding pressure reducing valve, electrical proportional valve and buffer tank. There are problems such as long overall delivery period, high price, and diaphragm needs to be replaced regularly. Using proportional valve for back pressure control has problems such as the proportional valve itself cannot withstand high temperature, and the proportional valve with smaller diameter is selected for anode tail exhaust due to less residual hydrogen, which often causes water blockage and pressure fluctuation. SUMMARY

[0004] The present application is to overcome the defects of the prior art and provide a fuel cell anode back pressure control system based on proportional valve.

[0005] The object of the present application can be achieved by the following technical solutions:

[0006] A fuel cell anode back pressure control system based on proportional valve, comprising a hydrogen delivery pipe, a stack, a hydrogen exhaust pipe, an inlet pressure sensor, an outlet pressure sensor, a hydrogen supply module, a heat dissipation module, a water vapor separation module and a proportional valve.

[0007] The hydrogen delivery pipe is connected with the hydrogen inlet of the stack, the inlet pressure sensor is used to detect the hydrogen pressure at the hydrogen inlet of the stack, and the hydrogen supply module is arranged on the hydrogen delivery pipe.

[0008] The hydrogen exhaust pipe is connected with the hydrogen outlet of the stack, the outlet pressure sensor is used to detect the hydrogen pressure at the hydrogen outlet of the stack, the heat dissipation module, the water vapor separation module and the proportional valve are arranged in sequence on the hydrogen exhaust pipe, and the proportional valve is connected to the hydrogen tail exhaust.

[0009] Further, the heat dissipation module comprises a cooling plate heat exchanger and corresponding pipelines, the hot side of the cooling plate heat exchanger is communicated with the hydrogen outlet of the stack and the water vapor separation module, and the cold side of the cooling plate heat exchanger is communicated with cooling water.

[0010] Further, the water vapor separation module comprises a water vapor separation tank and a drain pipe, the upper portion of the water vapor separation tank is provided with a hydrogen inlet hole and a hydrogen outlet hole, which are respectively communicated with the heat dissipation module and the proportional valve, the lower portion of the water vapor separation tank is provided with a drain port, the drain pipe is connected with the drain port, a liquid level pipe is arranged on the water vapor separation tank, and a liquid level sensor is arranged on the liquid level pipe.

[0011] Further, the liquid level pipe is a transparent PFA pipe, is communicated with the water vapor separation tank, and has the same water level height as the water vapor separation tank, and the liquid level sensor is a capacitive liquid level sensor and is used for detecting the liquid level.

[0012] Further, the drain pipe is connected to a drain tail, the drain pipe comprises two branches in parallel, and a drain electromagnetic valve and a drain ball valve are arranged on the two branches respectively, so that the drain can be automatically controlled through the drain electromagnetic valve or manually controlled through the drain ball valve.

[0013] Further, the hydrogen supply module comprises a hydrogen pretreatment and flow control system, a hydrogen humidification system and a hydrogen temperature control system which are sequentially arranged on the hydrogen conveying pipe, and the inlet of the hydrogen pretreatment and flow control system is communicated with the hydrogen source.

[0014] Further, the hydrogen pretreatment and flow control system comprises a pressure reducing valve, a filter, a mass flow controller and a three-way valve which are arranged on the hydrogen conveying pipe, the inlet of the three-way valve is connected with the mass flow controller, the outlet is connected with the hydrogen humidification system and the hydrogen temperature control system respectively, the pressure reducing valve is used for adjusting the pressure of the hydrogen sent into the hydrogen conveying pipe, the filter is used for filtering impurities, the mass flow controller is used for controlling the flow of the hydrogen sent into the stack, the inlet of the three-way valve is connected with the mass flow controller, and the outlet is connected with the hydrogen humidification system and the hydrogen temperature control system respectively, so as to distribute dry and wet flow.

[0015] Further, the mass flow controller is an electromagnetic valve.

[0016] Further, the hydrogen humidification system is used for spraying and humidifying the hydrogen, and comprises a humidification tank and a humidification tank circulating water path, the humidification tank is provided with an inlet and an outlet which are connected with the hydrogen pretreatment and flow control system and the hydrogen temperature control system respectively, and the humidification tank circulating water path is provided with a water pump, a water tank, a heater and a plate heat exchanger, the hot side outlet of the plate heat exchanger is provided with a temperature sensor, and the cold side of the plate heat exchanger is provided with a flow proportional valve.

[0017] Further, the hydrogen temperature control system is used for controlling the temperature of hydrogen entering the stack, comprising a gas heater and a plate heat exchanger arranged on the hydrogen delivery pipe, the outlet of the gas heater and the hot side outlet of the plate heat exchanger are provided with temperature sensors, and the cold side outlet of the plate heat exchanger is provided with a flow proportional valve.

[0018] Further, the controller is further included, which is in communication connection with the inlet pressure sensor, the outlet pressure sensor, the hydrogen supply module, the heat dissipation module and the water vapor separation module.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] (1) The heat dissipation module, the water vapor separation module and the proportional valve are used for back pressure control of the hydrogen path, compared with the diaphragm back pressure valve, the present application has low overall cost, short delivery period, no need for regular replacement of the module, and can accurately control the anode pressure during fuel cell testing, and has high precision and fast response.

[0021] (2) The heat dissipation module and the water vapor separator can well protect the proportional valve, the heat dissipation module performs cooling and primary condensation of water, and the water vapor separator performs water vapor separation, thereby reducing the problem of water accumulation in the laboratory pipeline caused by condensation of high-temperature and high-humidity gas, and avoiding pressure fluctuation.

[0022] (3) The hydrogen supply module comprises a hydrogen pretreatment and flow control system, a hydrogen humidification system and a hydrogen temperature control system, and can accurately control the hydrogen flow, humidity and temperature entering the stack. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structural schematic view of the present application;

[0024] Figure 2 is the change of hydrogen inlet pressure with time in the experiment;

[0025] Figure 3 is the change of average single piece voltage with time in the experiment;

[0026] REFERENCE NUMERALS:

[0027] 1, hydrogen pretreatment and flow control system, 2, hydrogen humidification system, 3, hydrogen temperature control system, 4, inlet pressure sensor, 5, outlet pressure sensor, 6, heat dissipation plate of heat dissipation module, 7, water vapor separation tank, 8, proportional valve, 9, liquid level sensor, 10, drain electromagnetic valve, 11, drain ball valve, 12, stack, 13, controller. DETAILED DESCRIPTION

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0029] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, some components are appropriately exaggerated in the drawings.

[0030] Example 1:

[0031] A fuel cell anode back pressure control system based on a proportional valve, such as Figure 1 As shown, it includes a hydrogen delivery pipe, a fuel cell stack 12, a hydrogen discharge pipe, an inlet pressure sensor 4, an outlet pressure sensor 5, a hydrogen supply module, a heat dissipation module, a water vapor separation module, and a proportional valve 8; the hydrogen delivery pipe is connected to the hydrogen inlet of the fuel cell stack 12, the inlet pressure sensor 4 is used to detect the hydrogen pressure at the hydrogen inlet of the fuel cell stack 12, and the hydrogen supply module is installed on the hydrogen delivery pipe.

[0032] The hydrogen exhaust pipe is connected to the hydrogen outlet of the fuel cell stack 12. The outlet pressure sensor 5 is used to detect the hydrogen pressure at the hydrogen outlet of the fuel cell stack 12. The heat dissipation module, the water vapor separation module and the proportional valve 8 are sequentially installed on the hydrogen exhaust pipe. The proportional valve 8 is connected to the hydrogen tail exhaust.

[0033] Controller 13 is connected to inlet pressure sensor 4, outlet pressure sensor 5, hydrogen supply module, heat dissipation module and water vapor separation module to achieve control.

[0034] The design concept of this invention is as follows:

[0035] During laboratory testing of fuel cell stack 12, the diaphragm back pressure valve is costly, has a long processing cycle, and requires frequent replacement. The proportional valve 8 is generally suitable for gas pressure control but is not heat-resistant. To address these issues, the inventors installed a heat dissipation module at the hydrogen outlet of fuel cell stack 12 to cool the high-temperature discharged water vapor. Liquid water is then separated by a water vapor separation module. At this point, the gas passing through proportional valve 8 is low-temperature and contains no liquid water. Therefore, by controlling the opening of proportional valve 8 using PID algorithms, the back pressure of the hydrogen path can be controlled, resulting in high overall pressure control accuracy and no pressure fluctuations.

[0036] The heat dissipation module includes a cooling plate heat exchanger 6 and corresponding pipelines, the hot side of the cooling plate heat exchanger 6 is communicated with the hydrogen outlet of the stack 12 and the water vapor separation module, the high-temperature and high-humidity gas discharged from the hydrogen outlet of the stack 12 is introduced into the cooling plate heat exchanger 6, the cold side of the cooling plate heat exchanger 6 is introduced into cooling water which can be provided by a laboratory cooling water main pipeline, the cold side and the hot side are heat-exchanged, so that the high-temperature and high-humidity gas is cooled. In actual testing, the cooling plate heat exchanger 6 for hydrogen tail discharge can reduce the high-temperature and high-humidity gas (90℃ 100% RH) to 30℃ 100% RH or below, so that the gas is cooled to the safe temperature of the proportional valve 8, and a large amount of liquid water can be precipitated in the heat dissipation module.

[0037] The water vapor separation module includes a water vapor separation tank 7 and a drain pipe, the upper part of the water vapor separation tank 7 is provided with a hydrogen inlet hole and a hydrogen outlet hole which are communicated with the heat dissipation module and the proportional valve 8 respectively, the lower part of the water vapor separation tank 7 is provided with a water outlet, the drain pipe is connected with the water outlet, a liquid level pipe is installed on the water vapor separation tank 7, and a liquid level sensor 9 is installed on the liquid level pipe. In order to facilitate observation, the liquid level pipe is a transparent PFA pipe which is communicated with the water vapor separation tank 7, the water level height of the liquid level pipe is the same as that of the water vapor separation tank 7, and the liquid level sensor 9 is a capacitive liquid level sensor which is used for detecting the liquid level. The drain pipe is connected to a drain tail, and the drain pipe includes two branches which are connected in parallel, the two branches are respectively provided with a drain electromagnetic valve 10 and a drain ball valve 11, the drain electromagnetic valve 10 can be automatically controlled to drain water, and the drain ball valve 11 can be manually controlled to drain water.

[0038] In actual testing, the water precipitated after the high-humidity hydrogen in the anode cavity of the stack 12 is consumed, the cathode permeation water and the condensate water of the cooling plate heat exchanger 6 of the heat dissipation module are collected in the water vapor separation tank 7, when the liquid level sensor 9 detects that the liquid level reaches a high liquid level, the drain electromagnetic valve 10 can be controlled to be opened to drain part of the water, and after the testing is completed, the drain ball valve 11 can be manually opened to drain the water vapor separation tank 7.

[0039] Further, the hydrogen supply module is used for controlling the flow, humidity and temperature of the hydrogen entering the stack 12, including a hydrogen pretreatment and flow control system 1, a hydrogen humidification system 2 and a hydrogen temperature control system 3 which are sequentially arranged on the hydrogen conveying pipe, the inlet of the hydrogen pretreatment and flow control system 1 is communicated with a hydrogen source such as a laboratory hydrogen main pipeline, a hydrogen storage tank and the like.

[0040] The hydrogen pretreatment and flow control system 1 comprises a pressure reducing valve, a filter, a mass flow controller and a three-way valve arranged on the hydrogen delivery pipe, the inlet of the three-way valve is connected with the mass flow controller, the outlets are connected with the hydrogen humidification system 2 and the hydrogen temperature control system 3 respectively, the pressure reducing valve is used to adjust the pressure of the hydrogen sent into the hydrogen delivery pipe, the filter is used to filter impurities, the mass flow controller is used to control the flow of the hydrogen sent into the electric pile 12, the mass flow controller is an electromagnetic valve, the inlet of the three-way valve is connected with the mass flow controller, the outlets are connected with the hydrogen humidification system 2 and the hydrogen temperature control system 3 respectively, and the three-way valve is used to distribute dry and wet flows.

[0041] The hydrogen humidification system 2 is used to spray humidify the hydrogen, and comprises a humidification tank and a humidification tank circulating water path, the humidification tank is provided with an air inlet and an air outlet connected with the hydrogen pretreatment and flow control system 1 and the hydrogen temperature control system 3 respectively, the humidification tank circulating water path is provided with a water pump, a water tank, a heater and a plate heat exchanger, the hot side outlet of the plate heat exchanger is provided with a temperature sensor, the cold side of the plate heat exchanger is provided with a flow proportional valve, the hydrogen is sprayed into the humidification tank for humidification, the frequency conversion water pump controls the flow and pressure of the humidification tank circulating water path, the heater and the plate heat exchanger are used for heating and cooling, the water temperature can be determined according to the temperature sensor of the hot side outlet of the plate heat exchanger, the flow of the cooling liquid in the plate heat exchanger is controlled through the flow proportional valve of the cold side of the plate heat exchanger, and the heater can be directly controlled, so that the water temperature in the humidification tank is accurately adjusted to reach the set dew point temperature.

[0042] The hydrogen temperature control system 3 is used to control the temperature of the hydrogen entering the electric pile 12, and comprises a gas heater and a plate heat exchanger arranged on the hydrogen delivery pipe, the outlet of the gas heater and the hot side outlet of the plate heat exchanger are provided with temperature sensors, and the cold side outlet of the plate heat exchanger is provided with a flow proportional valve, the gas heater and the plate heat exchanger are used for heating and cooling, the temperature sensors of the outlet of the gas heater and the hot side outlet of the plate heat exchanger can determine the gas temperature, the flow of the cooling liquid in the plate heat exchanger is controlled through the flow proportional valve of the cold side of the plate heat exchanger, and the heater can be directly controlled, so that the temperature of the hydrogen entering the electric pile 12 is accurately adjusted.

[0043] Of course, in order to further improve the control accuracy of the whole electric pile 12 test system, corresponding filters, check valves, pressure regulating valves, flow sensors, pressure sensors, temperature sensors, ion concentration sensors and other conventional pipeline accessories are arranged in the pipeline, which will not be described here.

[0044] The following is the test record of the fuel cell stack:

[0045] The anode gas parameters entering the stack are: gas temperature 61.5℃, dew point temperature 60.7℃, flow 50.4NLPM, metering ratio 1.5, and the water content of the gas before entering the stack is 0.092g / s.

[0046] Cathode inlet gas parameters: gas temperature 59.8°C dew point temperature 59.1°C flow rate 160 NLPM metering ratio 2, the gas at this time contains 0.269 g / s of water before entering the stack

[0047] As shown in the test data, data is recorded every 0.1 second, the anode inlet pressure jumps upward from row 2010, the upward jump amplitude is 23 kPa, row 2080 ends this fluctuation, the duration is 8 seconds. Figure 2

[0048] As shown in the test data, data is recorded every 0.1 second, the anode inlet pressure jumps upward from row 2010, the upward jump amplitude is 23 kPa, row 2080 ends this fluctuation, the duration is 8 seconds. Figure 3

[0049] (1) Inlet: gas temperature 59.8°C dew point temperature 59.1°C flow rate 160 NLPM metering ratio 2

[0050] The gas at this time contains 0.269 g / s of water

[0051] Electrochemical reaction water production: total power 2940 W average voltage: 0.6177 V

[0052] The electrochemical reaction generates 0.444 g / s of water, all of which is liquid water, but due to the rise in stack air temperature, the humidity is not saturated, so the state when exiting the stack is unknown (liquid or gas), and about 10% of the water will penetrate into the anode.

[0053] Outlet: gas temperature 67°C dew point temperature unknown flow rate 144 NLPM

[0054] The gas at this time contains 0.366 g / s of water, which represents that although the gas volume is slightly reduced, there is no liquid water separation, and the water content should be between 0.269 g / s and 0.366 g / s.

[0055] Pass 6: gas temperature 20.3°C dew point temperature 20.3°C flow rate 144 NLPM

[0056] The gas at this time contains 0.029 g / s of water

[0057] The total liquid water amount is: 0.269 g / s-0.029 g / s+0.444 g / s*0.9=0.64 g / s

[0058] The Kv value of the proportional valve 8 at this time is 0.31, and by checking the instruction manual, it is found that the proportional valve 8 aperture is about 3.1 mm 2 . ​​

[0059] (2) Anode over-proportional valve 8 water quantity analysis:

[0060] Electrochemical reaction water generation permeation: total power 2940W average voltage: 0.6177V

[0061] The amount of water generated by the electrochemical reaction is 0.444g / s, and all the water generated is liquid water, but due to the rise in air temperature in the stack, the humidity is not saturated, so the state when it comes out of the stack is unknown (liquid or gas), and about 10% of the water will penetrate into the anode.

[0062] Stack out: gas temperature 59°C, dew point temperature 59°C, flow rate 16.8NLPM

[0063] The water content at this time is 0.029g / s.

[0064] The amount of liquid water in the stack 12 is: 0.092g / s-0.029g / s+0.444g / s*0.1=0.1074g / s (higher than the water content brought in by the gas)

[0065] Over-plate exchange 6: gas temperature 27.7°C, dew point temperature 27.7°C, flow rate 144NLPM

[0066] The water content at this time is 0.005g / s

[0067] The total amount of liquid water is: 0.092g / s-0.005g / s+0.444g / s*0.1=0.1314g / s

[0068] The Kv value of proportional valve 8 at this time is 0.02, and by checking the specification, the hole diameter of proportional valve 8 is about 0.5mm 2 .

[0069] (3) The total water content of the anode is 1 / 5 of the cathode, and the cross-sectional area is about 1 / 36 of the cathode, and in this case 0.5mm 2 The hole diameter is very easy to cause the flow rate of the front section to change or produce bubbles when water droplets pass through, causing the flow rate of the front section to change and block the water.

[0070] By using the water vapor separation tank 7 scheme of the present application, the volume of the water vapor separation tank 7 is calculated, the total cavity volume of the test bench is 5800ml, the anode cavity volume of the stack 12 is about 200ml (20 pieces), and the gas volume of the water vapor separation tank 7 is about 400ml. The water vapor separation tank 7 is opened by the drain electromagnetic valve 10 every time the water is drained, and the amount of water drained is 10ml. When the pressure is 150kPag, if the proportional valve 8 does not change the diameter, the overall pressure drops by about 0.39kPa.

[0071] The pressure fluctuation is 0.39kPa every 76 seconds, which is much better than the intermittent pressure fluctuation of about 20kPa.

[0072] The above experimental data prove the effectiveness of the present application, combined with the heat dissipation module + water vapor separation module + proportional valve 8 to control the back pressure of the hydrogen path, compared with the diaphragm back pressure valve, the overall cost of the present application is low, the delivery period is short, there is no need to replace the module regularly, and the anode pressure during the fuel cell test can be accurately controlled, and the precision is high, the response is fast.

[0073] The heat dissipation module and the water vapor separator can well protect the proportional valve 8, reduce the problem of laboratory pipeline water accumulation caused by high-temperature and high-humidity gas condensation, and avoid pressure fluctuation.

[0074] The above detailed description of the preferred embodiments of the present application. It should be understood that those skilled in the art can make many modifications and changes without creative labor according to the concept of the present application. Therefore, any technical solution obtained by logical analysis, reasoning or limited experiment on the basis of the prior art according to the concept of the present application shall be within the protection scope determined by the claims.

Claims

1. A fuel cell anode back pressure control system based on a proportional valve, characterized in that, It includes a hydrogen delivery pipe, fuel cell stack, hydrogen discharge pipe, inlet pressure sensor, outlet pressure sensor, hydrogen supply module, heat dissipation module, water vapor separation module, and proportional valve; The hydrogen delivery pipe is connected to the hydrogen inlet of the fuel cell stack. The inlet pressure sensor is used to detect the hydrogen pressure at the hydrogen inlet of the fuel cell stack. The hydrogen supply module is installed on the hydrogen delivery pipe. The hydrogen exhaust pipe is connected to the hydrogen outlet of the fuel cell stack. The outlet pressure sensor is used to detect the hydrogen pressure at the hydrogen outlet of the fuel cell stack. The heat dissipation module, water vapor separation module and proportional valve are sequentially installed on the hydrogen exhaust pipe. The proportional valve is connected to the hydrogen tail exhaust. The heat dissipation module includes a cooling plate heat exchanger and corresponding pipelines. The hot side of the cooling plate heat exchanger is connected to the hydrogen outlet of the fuel cell stack and the water vapor separation module, and the cold side of the cooling plate heat exchanger is supplied with cooling water. The water vapor separation module includes a water vapor separation tank and a drain pipe. The water vapor separation tank has a hydrogen inlet and a hydrogen outlet at the top, which are respectively connected to the heat dissipation module and the proportional valve. The water vapor separation tank has a drain outlet at the bottom, and the drain pipe is connected to the drain outlet. The water vapor separation tank is equipped with a liquid level pipe, and a liquid level sensor is installed on the liquid level pipe.

2. The fuel cell anode back pressure control system based on a proportional valve according to claim 1, characterized in that, The drain pipe is connected to the drain tailpipe and includes two parallel branches, each equipped with a drain solenoid valve and a drain ball valve.

3. The fuel cell anode back pressure control system based on a proportional valve according to claim 1, characterized in that, The hydrogen supply module includes a hydrogen pretreatment and flow control system, a hydrogen humidification system, and a hydrogen temperature control system, which are sequentially arranged on the hydrogen delivery pipe. The inlet of the hydrogen pretreatment and flow control system is connected to the hydrogen source.

4. The fuel cell anode back pressure control system based on a proportional valve according to claim 3, characterized in that, The hydrogen pretreatment and flow control system includes a pressure reducing valve, a filter, a mass flow controller, and a three-way valve installed on the hydrogen delivery pipe. The inlet of the three-way valve is connected to the mass flow controller, and the outlet is connected to the hydrogen humidification system and the hydrogen temperature control system, respectively. The pressure reducing valve is used to adjust the pressure of the hydrogen delivered into the hydrogen delivery pipe. The filter is used to filter impurities. The mass flow controller is used to control the flow rate of hydrogen delivered into the fuel cell stack. The inlet of the three-way valve is connected to the mass flow controller, and the outlet is connected to the hydrogen humidification system and the hydrogen temperature control system, respectively, for distributing dry and wet flow rates.

5. A fuel cell anode back pressure control system based on a proportional valve according to claim 4, characterized in that, The mass flow controller is a solenoid valve.

6. The fuel cell anode back pressure control system based on a proportional valve according to claim 3, characterized in that, The hydrogen humidification system includes a humidification tank and a humidification tank circulation water circuit. The humidification tank is equipped with an air inlet and an air outlet, which are respectively connected to the hydrogen pretreatment and flow control system and the hydrogen temperature control system. The humidification tank circulation water circuit is equipped with a water pump, a water tank, a heater and a plate heat exchanger. The hot side outlet of the plate heat exchanger is equipped with a temperature sensor and the cold side of the plate heat exchanger is equipped with a flow proportional valve.

7. A fuel cell anode back pressure control system based on a proportional valve according to claim 3, characterized in that, The hydrogen temperature control system includes a gas heater and a plate heat exchanger installed on the hydrogen delivery pipe. Temperature sensors are installed at the outlet of the gas heater and the hot side outlet of the plate heat exchanger, and a flow proportional valve is installed at the cold side outlet of the plate heat exchanger.

8. The fuel cell anode back pressure control system based on a proportional valve according to claim 1, characterized in that, It also includes a controller, which is communicatively connected to an inlet pressure sensor, an outlet pressure sensor, a hydrogen supply module, a heat dissipation module, a water vapor separation module, and a proportional valve.

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