CN117869353A - Expected service life test bench and method for turbine air compressor of fuel cell - Google Patents

Abstract

The invention provides a test bench and a method for the life expectancy of a fuel cell turbine air compressor, wherein the test bench comprises an air filter, a pressure end air inlet flowmeter, a pressure sensor, a temperature sensor, a tested air compressor, a first vortex end air inlet flowmeter, a second vortex end air inlet flowmeter, a first vortex end air inlet throttle valve, a second vortex end air inlet throttle valve, an atomization water sprayer, an electric heater, an air pressure source and pressure stabilizing device, a vortex end external air supply throttle valve, a flow resistance simulator, a pressure end air outlet throttle valve, a first pressure end back pressure valve, a second pressure end back pressure valve, a first pressure end air outlet flowmeter, a second pressure end air outlet flowmeter, an intercooler, a water pump, a radiator and a water supplementing water tank; the test bench has two working modes of self-circulation and external air supply, and the life expectancy of the air compressor under the common working condition can be calculated by combining the fault-free operation time under the acceleration working condition and the acceleration coefficient.

Description

A fuel cell turbine air compressor life expectancy test bench and method

Technical Field

The invention relates to the technical field of air compressors for fuel cell systems, in particular to a fuel cell turbine air compressor life expectancy test bench and method.

Background technique

The fuel cell air compressor is the core component of the fuel cell air supply subsystem and the auxiliary component that consumes the most power in the entire fuel cell system. It can provide the fuel cell with air of a certain flow rate and pressure to meet the oxygen demand of the fuel cell under different working conditions. However, with the development of high-power fuel cells, the fuel cell's demand for the air compressor pressure ratio and flow rate continues to increase. While improving the air compressor flow rate and pressure ratio, it also leads to an increase in the air compressor's parasitic power consumption. Among them, the turbine air compressor uses the fuel cell tail exhaust energy to drive the turbine to work and recover the tail exhaust energy, thereby improving the system efficiency. Therefore, the turbine air compressor with turbine energy recovery function has become the current mainstream technology route.

Considering that the tail exhaust of the fuel cell contains water vapor and other components, the liquid water condensed during the energy recovery process of the turbine air compressor may cause erosion and other damage to the turbine, thereby affecting the reliability of the system. If the air compressor is unstable or has a short life, the overall performance of the fuel cell system will be reduced and the maintenance cost of the system will increase. Therefore, it is necessary to reasonably design the turbine air compressor test bench and test method to simulate the actual working conditions of the system to evaluate the performance of the turbine air compressor such as life.

Summary of the invention

In view of this, the purpose of the present invention is to provide a fuel cell turbine air compressor life expectancy test bench and method, which can carry out fuel cell turbine air compressor life expectancy test, has universality, can simulate the working conditions of the turbine air compressor in the actual fuel cell system, and can meet the life expectancy test requirements of turbine air compressors of various power levels.

To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a fuel cell turbine air compressor life expectancy test bench, including an air filter, a pressure end intake flow meter, a pressure sensor, a temperature sensor, a tested air compressor, a first vortex end intake flow meter, a second vortex end intake flow meter, a first vortex end intake throttle valve, a second vortex end intake throttle valve, an atomizing water sprayer, an electric heater, an air pressure source and a pressure stabilizing device, an external vortex end air supply throttle valve, a flow resistance simulator, a pressure end exhaust throttle valve, a first pressure end back pressure valve, a second pressure end back pressure valve, a first pressure end outlet flow meter, a second pressure end outlet flow meter, an intercooler, a water pump, a radiator, and a water supply tank; the test bench has two working modes of self-circulation and external air supply, which can simulate the tail exhaust pressure and flow of the fuel cell and pass them into the vortex end;

Among them, for the sensors used in the gas circuit of the test bench, the pressure and temperature sensors after the air filter are used to monitor the intake state; the pressure and temperature sensors at the outlet of the tested air compressor are used to monitor the exhaust state; there are two flow meters, one large and one small, in the parallel flow channel after the intercooler, which are used to detect the pressure end outlet flow of large and small flow air compressors respectively; two flow meters, one large and one small, in the parallel flow channel at the vortex end are used for large flow and small flow tests respectively; the pressure and temperature sensors after the vortex end flow meter are used to monitor the intake state of the vortex end; the pressure and temperature sensors at the outlet of the vortex end are used to monitor the exhaust state of the vortex end;

Among them, the sensors used for the water circuit of the test bench include the temperature and pressure sensors at the water pump outlet, which are used to monitor the water temperature and water pressure after cooling; the temperature and pressure sensors at the cooling channel outlet of the tested air compressor are used to monitor the internal temperature of the air compressor and the water pressure of the branch.

In a preferred embodiment, air enters the compression end of the air compressor to be tested through an air filter and a compression end intake flow meter, and the air enters the intercooler after being compressed. After being cooled by the intercooler, the outlet gas temperature is reduced. For a small flow air compressor, the first compression end back pressure valve is used to adjust the back pressure, and the second compression end back pressure valve is normally closed. For a large flow air compressor, the second compression end back pressure valve is used to adjust the back pressure, and the first compression end back pressure valve is normally closed. After the air flows out of the back pressure valve, the compression end exhaust throttle valve is normally closed, and the flow resistance and oxygen consumption in the fuel cell are simulated by a flow resistance simulator, and the air after passing through the flow resistance simulator is introduced into the vortex end. At this time, the external air supply throttle valve at the vortex end is closed, and the air is heated to a specified temperature by an electric heater, and humidified by an atomizing water sprayer to simulate the humid air at the outlet of the fuel cell. If the current flow rate is small, the first vortex end intake throttle valve is opened, and the second vortex end intake throttle valve is normally closed. If the flow rate is large at this time, the second vortex end intake throttle valve is opened, and the first vortex end intake throttle valve is normally closed. Finally, the humid high-pressure air is discharged into the atmosphere after energy recovery through vortex end expansion.

In a preferred embodiment, air enters the compression end of the tested air compressor through an air filter and a compression end intake flow meter, and the air enters the intercooler after being compressed. After being cooled by the intercooler, the outlet gas temperature is reduced. For a small-flow air compressor, the first compression end back pressure valve is used to adjust the back pressure, and the second compression end back pressure valve is normally closed. For a large-flow air compressor, the second compression end back pressure valve is used to adjust the back pressure, and the first compression end back pressure valve is normally closed. After the air flows out of the back pressure valve, the compression end exhaust throttle valve is fully opened to directly exhaust the air. The flow resistance simulator adjusts the flow resistance to the maximum, that is, it is normally closed. At this time No air will pass through the flow resistance simulator; the external air supply throttle valve at the turbine end is fully opened, and stable air with target flow and pressure is supplied to the turbine end through the air source and the pressure stabilizing device; the air is heated to a specified temperature by an electric heater, and humidified by an atomizing water sprayer to simulate the wet air at the outlet of the fuel cell. If the current flow rate is small, the air intake throttle valve at the first turbine end is opened, and the air intake throttle valve at the second turbine end is normally closed; if the flow rate is large at this time, the air intake throttle valve at the second turbine end is opened, and the air intake throttle valve at the first turbine end is normally closed; finally, the humid high-pressure air is discharged into the atmosphere after energy recovery through expansion at the turbine end.

The present invention also provides a method for testing the expected life of a fuel cell turbine air compressor, which adopts the above-mentioned expected life test bench for a fuel cell turbine air compressor; by setting up two air compressor prototypes, respectively operating them under normal operating conditions and accelerated operating conditions, the life decay rates of the two air compressors under different operating conditions are obtained, and the acceleration coefficient of the accelerated operating condition relative to the normal operating condition is calculated based on this, and the expected life of the air compressor under normal operating conditions is further calculated in combination with the trouble-free operation time of the air compressor under the accelerated operating condition.

In a preferred embodiment, referring to the definition of the end point of fuel cell life in GB/T 38914-2020 "Test and Evaluation Method for Service Life of Proton Exchange Membrane Fuel Cell Stacks for Vehicles", the life of the air compressor is defined as: the cumulative usage time of the air compressor when the air compressor cannot operate normally after endurance testing or the efficiency drops to a certain value under rated operating conditions.

In a preferred embodiment, common operating conditions and accelerated operating conditions are respectively prepared, and durability tests under the common operating conditions and accelerated operating conditions are carried out.

In a preferred embodiment, referring to the power output curve of the fuel cell based on the Chinese operating conditions in the draft for comments of the national standard "Durability Test Method for Fuel Cell Engines and Key Components" under development, a durability cycle test is carried out according to the fuel cell engine cycle operating condition curve in combination with a certain fuel cell engine, and the speed change of the air compressor carried by it is recorded to obtain the air compressor speed operating condition curve, which is divided by the rated speed of the air compressor to obtain the speed proportion curve, and this operating condition is defined as a common operating condition.

In a preferred embodiment, the life decay rate of the air compressor is increased by increasing the variable load frequency and load of the air compressor, an alternating working condition is used as the acceleration working condition for the air compressor test, and the air compressor is set to cycle between the minimum speed and the rated speed, and this working condition is defined as the acceleration working condition.

In a preferred embodiment, the test steps are as follows: two prototypes are set to be tested for the same time, without any faults during the test, and the efficiency under rated conditions is retested at regular intervals, the current efficiency and the accumulated running time are recorded respectively, and the efficiency and time data are linearly fitted to obtain the life decline curve. At this time, the slope ratio of the life decline curve of the air compressor under the common working condition and the accelerated working condition is the acceleration coefficient. The calculation formula of the acceleration coefficient is as follows:

Where A is the acceleration factor, _kc is the slope of the life decay curve under common working conditions, and _ka is the slope of the life decay curve under accelerated working conditions.

In a preferred embodiment, the expected life of the air compressor is calculated by combining the trouble-free operation time test of the air compressor under accelerated conditions:

T _expect ＝T _MTBF ×A

Where, T _expect is the expected life of the air compressor, in hours; T _MTBF is the trouble-free operating time, in hours.

Compared with the prior art, the present invention has the following beneficial effects:

1. The test bench designed by the present invention adopts the form of dual flow channels in parallel, and two flow channels are respectively set at the pressure end outlet and the vortex end inlet. A large flow meter flow channel is used for a large flow air compressor, and a small flow meter flow channel is used for a small flow air compressor. The design of dual flow channels in parallel enables the test bench to have a wider flow test range, which can meet the testing requirements of air compressors of various power levels.

2. The present invention simulates the flow resistance of the internal flow channel of the fuel cell and the oxygen consumption of the reaction through a flow resistance simulator. At the same time, the compressed air after the flow resistance simulator or after the gas source and the pressure stabilizing device is heated and humidified through an electric heater and an atomizing water sprayer to simulate the tail exhaust state of the fuel cell, which can make the turbine air compressor turbine end intake closer to reality.

3. The present invention has two working modes, which can be used to carry out joint testing (self-circulation mode), that is, the gas at the compression end is simulated consumed and then passed into the turbine end; or they can be tested separately (external air supply mode), that is, the compression end and the turbine end can be tested separately, or while the air is compressed at the compression end, air with a certain flow rate and pressure can be directly supplied to the turbine end through the air source and the pressure stabilizing device. The working mode can be flexibly selected according to experimental requirements.

4. The present invention can estimate the expected life of the air compressor with a shorter testing time. By setting two prototypes to work under normal working conditions and accelerated working conditions respectively, the acceleration factor is obtained through the life decay rate. Combined with the accelerated working condition test time, the expected life of the air compressor can be obtained by calculation in a shorter time, overcoming the shortcomings of conventional durability testing, such as long time period and high manpower and material costs.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a system block diagram of an embodiment of the present invention;

Figure 2 shows a common operating condition, where the horizontal axis is time and the vertical axis is the percentage of the rated speed;

Figure 3 shows the acceleration condition, where the horizontal axis is time and the vertical axis is speed;

Reference numerals:

1 air filter, 2 pressure end intake flow meter, 3 pressure sensor, 4 temperature sensor, 5 tested air compressor, 6 first vortex end intake flow meter, 7 second vortex end intake flow meter, 8 first vortex end intake throttle valve, 9 second vortex end intake throttle valve, 10 atomizing water sprayer, 11 electric heater, 12 air pressure source and pressure stabilizing device, 13 vortex end external air supply throttle valve, 14 flow resistance simulator, 15 pressure end exhaust throttle valve, 16 first pressure end back pressure valve, 17 second pressure end back pressure valve, 18 first pressure end outlet flow meter, 19 second pressure end outlet flow meter, 20 intercooler, 21 water pump, 22 radiator, 23 water supply tank.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application; as used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and/or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and/or their combinations.

As shown in FIG1 , a fuel cell turbine air compressor life expectancy test bench is characterized in that the test bench includes an air filter 1, a pressure end intake flow meter 2, a pressure sensor 3, a temperature sensor 4, a tested air compressor 5, a first vortex end intake flow meter 6, a second vortex end intake flow meter 7, a first vortex end intake throttle valve 8, a second vortex end intake throttle valve 9, an atomizing water sprayer 10, an electric heater 11, an air pressure source and a pressure stabilizing device 12, a vortex end external air supply throttle valve 13, a flow resistance simulator 14, a pressure end exhaust throttle valve 15, a first pressure end back pressure valve 16, a second pressure end back pressure valve 17, a first pressure end outlet flow meter 18, a second pressure end outlet flow meter 19, an intercooler 20, a water pump 21, a radiator 22, and a water supply tank 23. The test bench has two working modes: self-circulation and external air supply, and can simulate the tail exhaust pressure and flow of the fuel cell and pass it into the vortex end.

Among them, for the sensors used in the air circuit of the test bench (the solid arrow part in Figure 1), the pressure and temperature sensors after the air filter 1 are used to monitor the intake state; the pressure and temperature sensors at the outlet of the tested air compressor 5 are used to monitor the exhaust state; there are two flow meters, one large and one small, in the parallel flow channel after the intercooler 20, which are respectively used to detect the pressure end outlet flow of large-flow and small-flow air compressors; the functions of the two flow meters, one large and one small, in the parallel flow channel at the vortex end are similar to those at the pressure end outlet, and are respectively used for large-flow and small-flow tests; the temperature and pressure sensors after the vortex end flowmeter are used to monitor the intake state of the vortex end; the pressure and temperature sensors at the vortex end outlet are used to monitor the exhaust state of the vortex end.

Among them, the sensors used for the water circuit of the test bench (the dotted arrow part in Figure 1) are the temperature and pressure sensors at the outlet of the water pump 21, which are used to monitor the water temperature and water pressure after cooling; the temperature and pressure sensors at the outlet of the cooling flow channel of the tested air compressor 5 are used to monitor the internal temperature of the air compressor and the water pressure of the branch.

The test bench has a self-circulation working mode, characterized in that: air enters the pressure end of the tested air compressor through the air filter 1 and the pressure end intake flow meter 2, and the air enters the intercooler 20 after being compressed. After being cooled by the intercooler 20, the outlet gas temperature is reduced. For a small flow air compressor, the first pressure end back pressure valve 16 is used to adjust the back pressure, and the second pressure end back pressure valve 17 is normally closed. For a large flow air compressor, the second pressure end back pressure valve 17 is used to adjust the back pressure, and the first pressure end back pressure valve 16 is normally closed. After the air flows out of the back pressure valve, the pressure end exhaust throttle valve 15 is normally closed, and the flow resistance simulator 14 simulates the flow resistance and oxygen consumption in the fuel cell. The air after passing through the flow resistance simulator 14 is introduced into the vortex end. At this time, the external air supply throttle valve 13 of the vortex end is closed, and the air is heated to a specified temperature by the electric heater 11, and humidified by the atomizing water sprayer 10 to simulate the wet air at the outlet of the fuel cell. If the current flow rate is small, the first vortex end intake throttle valve 8 is opened, and the second vortex end intake throttle valve 9 is normally closed. If the flow rate is large at this time, the second vortex end intake throttle valve is opened, and the first vortex end intake throttle valve is normally closed. Finally, the humid high-pressure air is discharged into the atmosphere after energy recovery through vortex end expansion.

The test bench has an external air supply working mode, which is characterized in that: air enters the pressure end of the tested air compressor through the air filter 1 and the pressure end intake flow meter 2, and the air enters the intercooler 20 after being compressed. After being cooled by the intercooler 20, the outlet gas temperature is reduced. For small-flow air compressors, the first pressure end back pressure valve 16 is used to adjust the back pressure, and the second pressure end back pressure valve 17 is normally closed. For large-flow air compressors, the second pressure end back pressure valve 17 is used to adjust the back pressure, and the first pressure end back pressure valve 16 is normally closed. After the air flows out of the back pressure valve, the pressure end exhaust throttle valve 15 is fully opened to directly exhaust the air. The flow resistance simulator 14 adjusts the flow resistance to the maximum, that is, it is normally closed, and no air will pass through the flow resistance simulator 14 at this time. The external air supply throttle valve 13 at the turbine end is fully opened, and stable air with target flow and pressure is supplied to the turbine end through the air source 12 and the pressure stabilizing device. The air is heated to a specified temperature by an electric heater 11 and humidified by an atomizing water sprayer 10 to simulate the wet air at the outlet of the fuel cell. If the current flow rate is small, the first turbine end air intake throttle valve 8 is opened, and the second turbine end air intake throttle valve 9 is normally closed. If the flow rate is large at this time, the second turbine end air intake throttle valve 9 is opened, and the first turbine end air intake throttle valve 8 is normally closed. Finally, the humid high-pressure air is discharged into the atmosphere after energy recovery through turbine end expansion.

Based on the test bench, a fuel cell turbine air compressor life expectancy test method is designed, which is characterized by: by setting up two air compressor prototypes, respectively operating them under normal operating conditions and accelerated operating conditions, obtaining the life decay rates of the two air compressors under different operating conditions, and based on this, calculating the acceleration coefficient of the accelerated operating condition relative to the normal operating condition, and further calculating the expected life of the air compressor under normal operating conditions in combination with the trouble-free operating time under the accelerated operating condition.

The described method for testing the expected life of a fuel cell turbine air compressor refers to the definition of the end point of fuel cell life in GB/T38914-2020 "Test and Evaluation Method for Service Life of Proton Exchange Membrane Fuel Cell Stacks for Vehicles", and defines the life of the air compressor as: the cumulative usage time of the air compressor when the air compressor cannot operate normally after endurance testing or the efficiency drops to a certain value (10%) under rated operating conditions.

The method for testing the expected life of a fuel cell turbine air compressor respectively formulates common operating conditions and accelerated operating conditions, and conducts durability tests under the common operating conditions and accelerated operating conditions.

Referring to the power output curve of the fuel cell based on Chinese operating conditions in the draft for comments of the national standard "Durability Test Method for Fuel Cell Engines and Key Components", a durability cycle test was carried out on a certain fuel cell engine according to the fuel cell engine cycle operating condition curve, and the speed change of the air compressor carried by it was recorded to obtain the air compressor speed operating condition curve, which was divided by the rated speed of the air compressor to obtain the speed proportion curve, and this operating condition was defined as a common operating condition, as shown in Figure 2.

The life decay rate of the air compressor is increased by increasing the variable load frequency and load of the air compressor. The alternating working condition is used as the acceleration working condition for the air compressor test. The air compressor is set to cycle between the minimum speed and the rated speed. This working condition is defined as the acceleration working condition, as shown in Figure 3.

The method for testing the expected life of a fuel cell turbine air compressor is characterized in that the testing steps are as follows: two prototypes are set to be tested for the same time, without any faults during the test, and the efficiency under rated conditions is retested at regular intervals, the current efficiency and cumulative operating time are recorded respectively, and the efficiency and time data are linearly fitted to obtain a life decay curve. At this time, the ratio of the slope of the life decay curve of the air compressor under normal conditions and accelerated conditions is the acceleration coefficient, and the acceleration coefficient calculation formula is as follows.

Where A is the acceleration factor, _kc is the slope of the life decay curve under common working conditions, and _ka is the slope of the life decay curve under accelerated working conditions.

Based on the acceleration factor, combined with the trouble-free running time test of the air compressor under accelerated conditions, the expected life of the air compressor is calculated:

T _expect ＝T _MTBF ×A

Where, T _expect is the expected life of the air compressor, in hours; T _MTBF is the trouble-free operating time, in hours.

In summary, in order to meet the testing requirements of the fuel cell turbine air compressor, this embodiment designs a test bench. The test bench has a wide flow test range, can simulate the actual tail exhaust state of the fuel cell, and has two working modes: internal circulation and external air supply. In order to further obtain the expected life of the turbine air compressor, common operating conditions and accelerated operating conditions are designed for testing the expected life of the turbine air compressor, and a life calculation method is given.

Claims (10)

1. The life expectancy test bench of the turbine air compressor of the fuel cell, characterized by that, including air cleaner, pressure end air intake flowmeter, pressure sensor, temperature sensor, air compressor to be tested, first vortex end air intake flowmeter, second vortex end air intake flowmeter, first vortex end air intake throttle valve, second vortex end air intake throttle valve, atomization water sprayer, electric heater, air pressure source and pressure stabilizer, vortex end external air supply throttle valve, flow resistance simulator, pressure end air exhaust throttle valve, first pressure end back pressure valve, second pressure end back pressure valve, first pressure end air outlet flowmeter, second pressure end air outlet flowmeter, intercooler, water pump, radiator, make-up water tank; the test bench has two working modes of self-circulation and external air supply, and can simulate the tail discharge pressure and flow of the fuel cell and lead the tail discharge pressure and flow into the vortex end;

the pressure and temperature sensor behind the air filter is used for monitoring the air inlet state aiming at the sensor used by the air circuit of the test bench; the pressure and temperature sensor of the outlet of the air compressor to be tested is used for monitoring the air outlet state; a large flowmeter and a small flowmeter are arranged in the parallel flow channel behind the intercooler and are respectively used for detecting the outlet flow of the pressure end of the high-flow air compressor and the outlet flow of the pressure end of the low-flow air compressor; the large flow meter and the small flow meter in the vortex end parallel flow channel are respectively used for testing large flow and small flow; the pressure and temperature sensor behind the vortex end flowmeter is used for monitoring the vortex end air inlet state; the pressure and temperature sensor of the outlet of the vortex end is used for monitoring the gas outlet state of the vortex end;

wherein the sensor used for the waterway of the test bench, the temperature and pressure sensor at the outlet of the water pump is used for monitoring the water temperature and water pressure after cooling; the outlet temperature of the cooling flow passage of the air compressor to be measured and the pressure sensor are used for monitoring the internal temperature of the air compressor and the water pressure of the branch.

2. The life expectancy test bench of a fuel cell turbine air compressor according to claim 1, wherein air enters a pressure end of a tested air compressor through an air filter and a pressure end air inlet flowmeter, the air enters an intercooler after being compressed, the temperature of outlet gas is reduced after being cooled by the intercooler, a first pressure end back pressure valve is adopted to adjust back pressure for a small-flow air compressor, a second pressure end back pressure valve is normally closed, a second pressure end back pressure valve is adopted to adjust back pressure for a large-flow air compressor, and the first pressure end back pressure valve is normally closed; after air flows out of the back pressure valve, the pressure end exhaust throttle valve is normally closed, flow resistance and oxygen consumption in the fuel cell are simulated through the flow resistance simulator, and the air after passing through the flow resistance simulator is introduced into the vortex end; at the moment, the external air supply throttle valve at the vortex end is closed, the air is heated to a specified temperature through the electric heater, and the air is humidified through the atomizing water sprayer so as to simulate the wet air at the outlet of the fuel cell; if the current flow is smaller, the first vortex-end air inlet throttle valve is opened, the second vortex-end air inlet throttle valve is normally closed, and if the current flow is larger, the second vortex-end air inlet throttle valve is opened, and the first vortex-end air inlet throttle valve is normally closed; finally, the wet high-pressure air is discharged into the atmosphere after being recycled by the expansion energy of the vortex end.

3. The life expectancy test bench of a fuel cell turbine air compressor according to claim 1, wherein air enters a pressure end of a tested air compressor through an air filter and a pressure end air inlet flowmeter, the air enters an intercooler after being compressed, the temperature of outlet gas is reduced after being cooled by the intercooler, a first pressure end back pressure valve is adopted to adjust back pressure for a small-flow air compressor, a second pressure end back pressure valve is normally closed, a second pressure end back pressure valve is adopted to adjust back pressure for a large-flow air compressor, and the first pressure end back pressure valve is normally closed; after the air flows out of the back pressure valve, the exhaust throttle valve at the pressure end is fully opened at the moment, so that the air is directly exhausted; the flow resistance simulator adjusts the flow resistance to the maximum, i.e. normally closed, when no air passes through the flow resistance simulator; fully opening a throttling valve for external air supply of the vortex end, and supplying stable air with target flow and pressure for the vortex end through an air source and a pressure stabilizing device; the air is heated to a specified temperature through an electric heater and humidified through an atomization water sprayer to simulate the wet air at the outlet of the fuel cell, if the current flow is smaller, a first vortex-end air inlet throttle valve is opened, a second vortex-end air inlet throttle valve is normally closed, if the current flow is larger, the second vortex-end air inlet throttle valve is opened, and the first vortex-end air inlet throttle valve is normally closed; finally, the wet high-pressure air is discharged into the atmosphere after being recycled by the expansion energy of the vortex end.

4. A method for testing the life expectancy of a fuel cell turbine air compressor, which is characterized in that the life expectancy testing bench of the fuel cell turbine air compressor is adopted; through setting up two air compressor machine prototype, place it in the operating mode that commonly uses and accelerate the operating mode respectively, obtain the life-span decay rate of two air compressors under the different operating modes to according to this, calculate the acceleration coefficient of acceleration operating mode relative to commonly used operating mode, combine the life-span under the commonly used operating mode of air compressor machine further calculation in the time of the no trouble operation under the acceleration operating mode.

5. The method for testing the life expectancy of a fuel cell turbine air compressor according to claim 4, wherein the life of the air compressor is defined as follows with reference to the definition of the end of life of the fuel cell in the method for testing and evaluating the life of a proton exchange membrane fuel cell stack for vehicles of GB/T38914-2020: the air compressor can not normally run after endurance test or the efficiency is reduced to a certain value under the rated working condition, and the accumulated service time of the air compressor is prolonged.

6. The method for testing the life expectancy of the air compressor of the fuel cell according to claim 4, wherein the common working condition and the acceleration working condition are respectively formulated, and the endurance test under the common working condition and the acceleration working condition is carried out.

7. The method for testing the life expectancy of the air compressor of the fuel cell according to claim 6, wherein the power output curve of the fuel cell based on the working condition of China in the research national Standard of durability test method of Fuel cell Engine and key parts is referred to, a certain fuel cell Engine is combined to carry out the durability cycle test according to the cycle working condition curve of the fuel cell Engine, the change of the rotation speed of the carried air compressor is recorded, the working condition curve of the rotation speed of the air compressor is obtained, the working condition is divided by the rated rotation speed of the air compressor, the working condition is defined as the common working condition, and the rated rotation speed is obtained.

8. The method for testing the life expectancy of the air compressor of the fuel cell according to claim 6, wherein the life decay rate of the air compressor is improved by improving the variable load frequency and the load of the air compressor, an alternating working condition is adopted as an acceleration working condition of the air compressor for testing, the air compressor is set to work between the lowest rotating speed and the rated rotating speed for circulation, and the working condition is defined as the acceleration working condition.

9. The method for testing the life expectancy of the air compressor of the fuel cell according to claim 8, wherein the testing steps are as follows: the method comprises the steps of setting two prototypes to test the same time respectively, testing the same time without faults, retesting the efficiency under the rated working condition at intervals, recording the current efficiency and the accumulated running time respectively, performing linear fitting on the efficiency and time data to obtain a life decay curve, wherein the slope ratio of the life decay curve of the air compressor under the common working condition and the acceleration working condition is an acceleration coefficient, and the acceleration coefficient has the following calculation formula:

wherein A is an acceleration coefficient, k _c Slope, k of life decay curve of common working condition _a Is the slope of the accelerated operating life decay curve.

10. The method for testing the life expectancy of the air compressor of the fuel cell turbine according to claim 9, wherein the life expectancy of the air compressor is calculated by combining a fault-free operation time test of the air compressor under an acceleration working condition:

T _expect ＝T _MTBF ×A

wherein T is _expect The unit is h, which is the life expectancy of the air compressor; t (T) _MTBF The unit is h for fault-free run time.