A hydrogen vehicle fuel cell system and control method thereof

Abstract

The invention provides a hydrogen energy vehicle fuel cell system, and relates to the technical field of fuel cell systems; the fuel cell system comprises a fuel cell stack, an air compressor, a stack outlet throttle valve, a hydrogen bottle, a voltage inspection module and a controller; the fuel cell stack is provided with an air inlet, an air outlet, a hydrogen inlet, a hydrogen outlet, a hydrogen exhaust valve and a water discharge valve; the stack outlet throttle valve is connected with the air outlet; the air compressor is connected with the fuel cell stack through the air inlet; an in-stack throttle valve is provided between the air compressor and the air inlet; the hydrogen bottle is connected with the fuel cell stack through the hydrogen inlet; an in-stack hydrogen valve is provided between the hydrogen bottle and the hydrogen inlet; the in-stack hydrogen valve is respectively connected with the hydrogen bottle and the hydrogen inlet; the controller is respectively electrically connected with the air compressor, the in-stack throttle valve, the stack outlet throttle valve, the in-stack hydrogen valve and the voltage inspection module; the invention also provides a control method for the hydrogen energy vehicle fuel cell system; the attenuation of fuel cell stack performance can be effectively slowed down.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell systems, and in particular to a hydrogen automobile fuel cell system and a control method thereof. Background Art

[0002] Compared with the currently widely used electric energy supply system, hydrogen energy, as an energy storage material in the transportation industry, has the characteristics and advantages of large-scale stable storage, continuous supply, long-distance transportation, and rapid replenishment. In the future energy architecture characterized by distributed and zero emissions, there will be a hydrogen energy system that coexists and complements the electric power system to jointly meet the energy needs of transportation, family life, and industrial production.

[0003] A fuel cell is an energy conversion device that converts the chemical energy of hydrogen and air (oxygen) into electrical energy through an electrochemical reaction. Since it does not go through a high-temperature combustion process, the only emission product is water, so there is no pollutant emission; at the same time, as long as the supply of hydrogen can be guaranteed, the fuel cell will continue to output electrical energy. Since fuel cells have broken through the efficiency limitations of the thermodynamic Carnot cycle and the traditional energy power model, they have become a cutting-edge technology in the development of modern science and technology. At present, new energy vehicles powered by fuel cells have made the most significant development. Major automakers in the world, including Toyota, Honda, General Motors, and Mercedes-Benz, are committed to the research and development of fuel cell hydrogen vehicles and are gradually launching them into mass production.

[0004] However, existing fuel cell hydrogen-powered vehicles have the problem of rapid performance degradation of the fuel cell stack, which is one of the important factors restricting the large-scale commercial application of fuel cell hydrogen-powered vehicles. Summary of the invention

[0005] The present invention aims to solve the technical problem of fuel cell stack performance degradation caused by poor consistency of voltage of each single cell in the existing fuel cell stack.

[0006] An embodiment of the present invention provides a hydrogen automobile fuel cell system, including a fuel cell stack, an air compressor, a stack throttle valve, a hydrogen cylinder, a voltage inspection module and a controller;

[0007] The stack is provided with an air inlet, an air outlet, a hydrogen inlet, a hydrogen outlet, a hydrogen exhaust valve and a water exhaust valve; the stack outlet throttle valve is connected to the air outlet;

[0008] The air compressor is connected to the fuel cell stack through the air inlet; a stack entry throttle valve is provided between the air compressor and the air inlet; the stack entry throttle valve is connected to the air compressor and the air inlet respectively;

[0009] The hydrogen cylinder is connected to the fuel cell stack through the hydrogen inlet; a hydrogen inlet valve is provided between the hydrogen cylinder and the hydrogen inlet; the hydrogen inlet valve is connected to the hydrogen cylinder and the hydrogen inlet respectively;

[0010] The controller is electrically connected to the air compressor, the stack entry throttle valve, the stack exit throttle valve, the stack entry hydrogen valve and the voltage inspection module respectively; the voltage inspection module is used to detect the voltage of each single cell in the battery stack.

[0011] In some preferred embodiments, the hydrogen automobile fuel cell system further includes an intercooler; the intercooler is disposed between the air compressor and the air inlet; the air compressor is connected to the air inlet through the intercooler.

[0012] In some preferred embodiments, the hydrogen automobile fuel cell system also includes a humidifier; the humidifier is arranged between the air compressor and the air inlet; the air compressor is connected to the air inlet through the humidifier; the stack throttle valve is connected to the air outlet through the humidifier.

[0013] In some preferred embodiments, the hydrogen energy automobile fuel cell system also includes a hydrogen circulation pump; the hydrogen circulation pump is electrically connected to the controller; the hydrogen circulation pump is respectively connected to the hydrogen outlet and the hydrogen inlet; a one-way valve is arranged between the hydrogen circulation pump and the hydrogen inlet; the one-way valve is respectively connected to the hydrogen circulation pump and the hydrogen inlet; the hydrogen circulation pump and the one-way valve are used in cooperation to circulate the unreacted hydrogen in the fuel cell stack to the fuel cell stack through the hydrogen inlet.

[0014] In some preferred embodiments, a pressure reducing valve is further provided between the hydrogen cylinder and the hydrogen valve for stack entry; the pressure reducing valve is communicated with the hydrogen cylinder and the hydrogen valve for stack entry, respectively.

[0015] In some preferred embodiments, a proportional valve is further provided between the hydrogen valve for entering the stack and the hydrogen inlet; the proportional valve is communicated with the hydrogen inlet and the hydrogen valve for entering the stack, respectively; and the proportional valve is electrically connected to the controller.

[0016] In some preferred embodiments, the hydrogen automobile fuel cell system also includes a water tank and a water pump; the fuel cell stack is also provided with a first water inlet and a first water outlet; the water tank is connected to the water inlet of the water pump through the intercooler; the water outlet of the water pump is connected to the first water inlet; the water outlet of the water pump is also connected to the water tank; the first water outlet is connected to the water inlet of the water pump; the water pump is electrically connected to the controller.

[0017] In some more preferred embodiments, the hydrogen automobile fuel cell system also includes a radiator and a thermostat; the radiator is electrically connected to the controller; the thermostat is provided with a second water inlet, a third water inlet and a second water outlet; the water outlet of the water pump is connected to the second water inlet; the water outlet of the water pump is also connected to the third water inlet through the radiator; the water tank is connected to the water outlet of the water pump through the radiator; the second water outlet is connected to the first water inlet.

[0018] In some preferred embodiments, the hydrogen automobile fuel cell system further includes a temperature sensor; the temperature sensor is electrically connected to the controller; the temperature sensor is disposed in the fuel cell stack to detect the temperature of water generated in the fuel cell stack.

[0019] In some preferred embodiments, the hydrogen automobile fuel cell system further includes a DC-DC booster; the DC-DC booster is electrically connected to the fuel cell stack and the controller, respectively.

[0020] The present invention also provides a control method for the above hydrogen automobile fuel cell system, comprising the following steps:

[0021] S1. The voltage inspection module detects the voltage value of each single cell in the battery stack and sends it to the controller;

[0022] S2, the controller determines whether the average voltage value of the single battery is less than a first preset threshold value, and determines whether the voltage difference value of the single battery is greater than a second preset threshold value; when the average voltage value of the single battery is less than the first preset threshold value, or the voltage difference value of the single battery is greater than the second preset threshold value, the controller controls the speed of the air compressor to increase to a third preset threshold value;

[0023] S3. When the time that the air compressor runs at the third preset threshold reaches a fourth preset threshold, and the controller determines that the average voltage value of the single cell is less than the first preset threshold or the voltage difference of the single cell is greater than the second preset threshold, the controller controls the hydrogen automobile fuel cell system to stop working.

[0024] In some preferred embodiments, before step S1, a startup step of the hydrogen energy vehicle fuel cell system is also included; the startup step is as follows:

[0025] T1, the controller determines whether there is a fault in the circuit of the hydrogen energy vehicle fuel cell system; if there is a fault, enters the fault mode; if there is no fault, controls the water pump to start;

[0026] T2, the controller controls the hydrogen discharge valve and the water discharge valve to be fully opened, and controls the hydrogen circulation pump to be turned on;

[0027] T3, the controller controls the hydrogen inlet valve and the proportional valve to open;

[0028] T4. When the opening time of the hydrogen inlet valve and the proportional valve reaches the fifth preset threshold, the controller controls the switching frequency of the hydrogen discharge valve to be the sixth preset value, and controls the switching frequency of the water discharge valve to be the seventh preset threshold; and then controls the inlet throttle valve and the air compressor to open.

[0029] In some preferred embodiments, in step S3, the controller controls the hydrogen automobile fuel cell system to stop working as follows:

[0030] P1. The controller controls the input current of the DC-DC booster so that the average voltage of each single cell in the battery stack is maintained between 770-830 mV; the controller controls the switching frequency of the hydrogen exhaust valve to the eighth preset threshold, and controls the switching frequency of the drain valve to the ninth preset threshold, and then controls the speed of the air compressor to increase to the tenth preset threshold;

[0031] P2. When the time for which the air compressor runs at the tenth preset threshold reaches the eleventh preset threshold, the controller controls the output and input currents of the DC-DC booster to be 0, and then controls the DC-DC booster to be turned off;

[0032] P3, the controller controls the air compressor, the inlet throttle valve and the outlet throttle valve to be closed;

[0033] P4. When the controller determines that the average voltage value of the single battery is less than the twelfth preset threshold value, the controller controls the hydrogen circulation pump, the hydrogen discharge valve and the water discharge valve to close;

[0034] P5, the controller controls the hydrogen inlet valve and the proportional valve to close;

[0035] P6. When the controller determines that the temperature of the water in the fuel cell stack is lower than the thirteenth preset threshold, the controller controls the water pump and the radiator to shut down.

[0036] The technical solution provided by the embodiment of the present invention has the following beneficial effects: the hydrogen energy automobile fuel cell system in the present invention comprises a fuel cell stack, an air compressor, a stack outlet throttle valve, a hydrogen bottle, a voltage inspection module and a controller; the fuel cell stack is provided with an air inlet, an air outlet, a hydrogen inlet, a hydrogen outlet, a hydrogen exhaust valve and a water exhaust valve; the stack outlet throttle valve is connected to the air outlet; the air compressor is connected to the fuel cell stack through the air inlet; an inlet throttle valve is provided between the air compressor and the air inlet; the inlet throttle valve is divided into The controller is electrically connected to the air compressor, the stack entry throttle valve, the stack exit throttle valve, the stack entry hydrogen valve and the voltage inspection module respectively; the voltage inspection module detects the voltage value of each single cell in the stack, and the controller determines the voltage of each single cell. Whether the average voltage value is less than the first preset threshold value, and whether the voltage difference of the single cell is greater than the second preset threshold value; when the average voltage value of the single cell is less than the first preset threshold value, or the voltage difference of the single cell is greater than the second preset threshold value, the controller controls the speed of the air compressor to increase to the third preset threshold value; through the sudden increase of air disturbance, the water generated in the battery stack is blown to the outside of the battery stack through the air outlet to prevent the condensation of liquid water due to excessive water vapor in the battery stack from affecting the consistency of the single cell voltage, thereby slowing down the attenuation of the battery stack performance; in addition, when the time for the air compressor to run at the third preset threshold value reaches the fourth preset threshold value, and the controller judges that the average voltage value of the single cell is less than the first preset threshold value or the voltage difference of the single cell is greater than the second preset threshold value, the controller controls the hydrogen energy vehicle fuel cell system to stop working, thereby ensuring that when the problem of the consistency of the single cell cannot be solved by increasing the speed of the air compressor, the hydrogen energy vehicle battery system is shut down to achieve the purpose of slowing down the attenuation of the battery stack performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the structure of the hydrogen automobile fuel cell system in Example 1 of the present invention.

[0038] Figure 2 yes Figure 1 Schematic diagram of the circuit connection of the fuel cell system of the hydrogen energy vehicle.

[0039] Figure 3 yes Figure 1 Flowchart of the startup steps in the control method of the fuel cell system of the hydrogen energy vehicle.

[0040] Figure 4 yes Figure 1 Flowchart of the control method of the fuel cell system of the hydrogen energy vehicle.

[0041] Figure 5 yes Figure 1 Flowchart of shutdown steps in the control method of the fuel cell system of the hydrogen energy vehicle.

[0042] Among them, 1. air compressor; 2. intercooler; 3. humidifier; 4. throttle valve for entering the stack; 5. throttle valve for leaving the stack; 6. water tank; 7. water pump; 8. radiator; 9. thermostat; 10. hydrogen cylinder; 11. pressure reducing valve; 12. hydrogen valve for entering the stack; 13. proportional valve; 14. hydrogen circulation pump; 15. one-way valve; 16. hydrogen discharge valve; 17. fuel cell stack; 18. voltage inspection module; 19. DC-DC booster; 20. controller; 21. drain valve; 22. temperature sensor. DETAILED DESCRIPTION

[0043] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0044] Please refer to Figure 1 and 2 An embodiment of the present invention provides a hydrogen automobile fuel cell system, including a fuel cell stack 17, an air compressor 1, an intercooler 2, a humidifier 3, a stack inlet throttle valve, a stack outlet throttle valve 5, a hydrogen cylinder 10, a pressure reducing valve 11, a stack inlet hydrogen valve 12, a proportional valve 13, a hydrogen circulation pump 14, a water tank 6, a water pump 7, a radiator 8, a thermostat 9, a DC-DC booster 19, a voltage inspection module 18 and a controller 20.

[0045] The controller 20 is an MCU controller, and the controller 20 is electrically connected to the air compressor 1, the stack entry throttle valve 4, the stack exit throttle valve 5, the stack entry hydrogen valve 12, the proportional valve 13, the hydrogen circulation pump 14, the water pump 7, the radiator 8, the DC-DC booster 19 and the voltage inspection module 18 respectively; the voltage inspection module 18 is used to detect the voltage of each single cell in the battery stack 17.

[0046] The stack 17 is a PEMFC stack, and a plurality of single cells are arranged inside the stack 17 (not shown in the figure); the stack 17 is provided with an air inlet, an air outlet, a hydrogen inlet, a hydrogen outlet, a hydrogen discharge valve 16 and a water discharge valve 21; the stack outlet throttle valve 5 is connected to the air outlet; a temperature sensor 22 is arranged inside the stack 17 for detecting the temperature of water generated in the stack 17; the temperature sensor 22 is electrically connected to the controller 20; the hydrogen discharge valve 16 is used to discharge the unreacted hydrogen in the stack 17 to the outside; the water discharge valve 21 is used to discharge the water generated in the stack 17 to the outside; the hydrogen discharge valve 16 and the water discharge valve 21 are electrically connected to the controller 20 respectively.

[0047] The air compressor 1 is connected to the fuel cell stack 17 through the air inlet; an intercooler 2, a humidifier 3 and an inlet throttle valve 4 are arranged in sequence between the air compressor 1 and the air inlet; the air compressor 1 is connected to the fuel cell stack 17 through the intercooler 2, the humidifier 3, the inlet throttle valve 4 and the air inlet in sequence; the air compressor 1 cooperates with the intercooler 2, the humidifier 3, the inlet throttle valve 4 and the air inlet to cool the outside air and then pressurize it into the fuel cell stack 17.

[0048] The stack outlet throttle valve 5 is connected to the air outlet through the humidifier 3 ; the stack outlet throttle valve 5 cooperates with the humidifier 3 and the stack outlet throttle valve 5 to discharge the unreacted air in the stack 17 to the outside of the stack 17 after humidification by the humidifier 3 .

[0049] The hydrogen cylinder 10 is connected to the fuel cell stack 17 through the hydrogen inlet; a pressure reducing valve 11, a hydrogen valve 12 and a proportional valve 13 are arranged between the hydrogen cylinder 10 and the hydrogen inlet; the hydrogen valve 12 is connected to the hydrogen inlet through the pressure reducing valve 11, the hydrogen valve 12 and the proportional valve 13 in sequence; a hydrogen circulation pump 14 is respectively connected to the hydrogen outlet and the hydrogen inlet; a one-way valve 15 is arranged between the hydrogen circulation pump 14 and the hydrogen inlet; the one-way valve 15 is respectively connected to the hydrogen circulation pump 14 and the hydrogen inlet; the hydrogen circulation pump 14 and the one-way valve 15 cooperate to circulate the unreacted hydrogen in the fuel cell stack 17 to the fuel cell stack 17 through the hydrogen inlet.

[0050] Furthermore, a first water inlet and a first water outlet are also provided on the battery stack 17; a second water inlet, a third water inlet and a second water outlet are provided on the thermostat 9; the water tank 6 is connected to the water inlet of the water pump 7 through the intercooler 2; the water outlet of the water pump 7 is connected to the second water inlet; the second water outlet is connected to the first water inlet; the first water outlet is connected to the water inlet of the water pump 7, and the cooling water in the battery stack 17 is circulated to the water inlet of the water pump 7; the water outlet of the water pump 7 is also connected to the third water inlet through the radiator 8; the water tank 6 is connected to the water outlet of the water pump 7 through the radiator 8. The thermostat 9 can open the second water inlet and / or the third water inlet according to a preset temperature threshold; the water pump 7 cools the water in the water tank 6 through the intercooler 2 and then transports it to the radiator 8 and the second water inlet of the thermostat 9; part of the cooling water flowing through the water pump 7 is further cooled through the radiator 8 and transported to the third water inlet of the thermostat 9; the thermostat 9 detects the water temperature of the cooling water at the second water inlet and the third water inlet, and decides to open the second water inlet and / or the third water inlet according to whether the water temperature of the cooling water is lower than the preset temperature threshold; the cooling water flowing through the second water outlet enters the battery stack 17 through the first water inlet to cool the battery stack 17. At the same time, a small part of the cooling water flowing through the radiator 8 will flow back to the water tank 6.

[0051] refer to Figure 3-5 The control method of the hydrogen energy vehicle fuel cell system in this embodiment includes the following steps:

[0052] Steps for starting up the hydrogen vehicle fuel cell system:

[0053] T1. The controller 20 determines whether there is a fault in the circuit of the hydrogen energy automobile fuel cell system; if there is a fault, it enters the fault mode; if there is no fault, it controls the water pump 7 to start.

[0054] Specifically, when the controller 20 determines that there is a fault in the circuit of the hydrogen-powered vehicle fuel cell system, an alarm message may be sent to the dashboard of the hydrogen-powered vehicle, wherein the alarm message includes a buzzer or a reminder sign.

[0055] T2. The controller 20 controls the hydrogen discharge valve 16 and the water discharge valve 21 to be fully opened, and controls the hydrogen circulation pump 14 to be turned on.

[0056] The normal working mode of the hydrogen discharge valve 16 and the water drain valve 21 is to close for a certain period of time and then open for a certain period of time. The controller 20 controls the hydrogen discharge valve 16 and the water drain valve 21 to be fully open, and the hydrogen discharge valve 16 and the water drain valve 21 are always in the open state.

[0057] T3, the controller 20 controls the hydrogen inlet valve 12 and the proportional valve 13 to open, and the hydrogen cylinder 10 delivers hydrogen to the fuel cell stack 17 through the pressure reducing valve 11, the hydrogen inlet valve 12, the proportional valve 13 and the hydrogen inlet; the residual gas on the anode side of the fuel cell stack 17 is replaced by the pressure generated at the moment of hydrogen introduction.

[0058] T4. When the opening time of the hydrogen valve 12 and the proportional valve 13 reaches the fifth preset threshold, the controller 20 controls the switching frequency of the hydrogen discharge valve 16 to be the sixth preset value, and controls the switching frequency of the water discharge valve 21 to be the seventh preset threshold; then controls the stack throttle valve 4 and the air compressor 1 to be opened; in order to more clearly reflect the scheme of this embodiment, illustratively, the rotation speed of the air compressor 1 during normal operation is 20000r / min, and the rotation speeds of air compressors 1 of different models and specifications during normal operation are different.

[0059] In this embodiment, the fifth preset threshold is 5s; as a variation of this embodiment, the fifth preset threshold may also be 4s or 6s.

[0060] Specifically, in this embodiment, the sixth preset value is closed for 12 seconds and opened for 0.2 seconds, that is, the hydrogen exhaust valve 16 is first closed for 12 seconds and then opened for 0.2 seconds, and the process is performed alternately.

[0061] Specifically, in this embodiment, the seventh preset value is closed for 8 seconds and opened for 0.3 seconds, that is, the drain valve 21 is first closed for 8 seconds and then opened for 0.3 seconds, and the process is performed alternately in sequence.

[0062] The control method during the operation of the hydrogen vehicle fuel cell system includes the following steps:

[0063] S1. The voltage inspection module 18 detects the voltage value of each single cell in the battery stack 17 and sends it to the controller 20.

[0064] S2. The controller 20 calculates and determines whether the average voltage value of the single cells in the battery stack 17 is less than a first preset threshold value, and determines whether the voltage difference of the single cells is greater than a second preset threshold value; when the average voltage value of the single cells is less than the first preset threshold value, or the voltage difference of the single cells is greater than the second preset threshold value, the controller 20 controls the speed of the air compressor 1 to increase to a third preset threshold value, and by suddenly generating air disturbances, blows the water generated in the battery stack 17 through the air outlet to the outside of the battery stack 17; prevents the water vapor in the battery stack 17 from condensing into liquid water due to excessive water vapor, thereby affecting the consistency of the voltage of the single cells, thereby slowing down the attenuation of the performance of the battery stack 17.

[0065] Specifically, in this embodiment, the first preset threshold is 500mV; the second preset threshold is 50mV; as a variation of this embodiment, the first preset threshold may also be 550mV; the second preset threshold may also be 45mV or 55mV.

[0066] Specifically, in this embodiment, the third preset threshold is 22000 r / min; as a variation of this embodiment, the third preset threshold may also be 26000 r / min.

[0067] S3. When the time that the air compressor 1 runs at the third preset threshold reaches the fourth preset threshold, and the controller 20 determines that the average voltage value of the single cell is less than the first preset threshold or the voltage difference of the single cell is greater than the second preset threshold, the controller 20 controls the hydrogen energy vehicle fuel cell system to stop working; thereby ensuring that when the problem of consistency of the single cell cannot be solved by increasing the speed of the air compressor 1, the hydrogen energy vehicle battery system is shut down to achieve the purpose of slowing down the performance degradation of the battery stack 17.

[0068] Specifically, in this embodiment, the fourth preset threshold is 0.5 min; as a variation of this embodiment, the fourth preset threshold may also be 2.5 min.

[0069] Further, in step S3, the controller 20 controls the hydrogen energy vehicle fuel cell system to stop working in the following steps:

[0070] P1, the controller 20 controls the input current of the DC-DC booster 19 so that the average voltage of each single cell in the battery stack 17 is maintained between 770-830 mV; the controller 20 controls the switching frequency of the hydrogen exhaust valve 16 to the eighth preset threshold, and controls the switching frequency of the water discharge valve 21 to the ninth preset threshold, and then controls the speed of the air compressor 1 to increase to the tenth preset threshold.

[0071] Specifically, in this embodiment, the eighth preset threshold is closed for 8 seconds and opened for 0.3 seconds, that is, the exhaust valve is first closed for 8 seconds and then opened for 0.3 seconds, and the processes are performed alternately in sequence.

[0072] Specifically, in this embodiment, the ninth preset threshold is closed for 4s and opened for 0.3s, that is, the drain valve 21 is first closed for 4s and then opened for 0.3s, and they are performed alternately in sequence; as a variation of this embodiment, the ninth preset threshold can also be closed for 6s and opened for 0.3s, that is, the drain valve 21 is first closed for 6s and then opened for 0.3s, and they are performed alternately in sequence.

[0073] Specifically, in this embodiment, the tenth preset threshold is 25000 r / min; as a variation of this embodiment, the tenth preset threshold may also be 26000 r / min.

[0074] P2. When the time during which the air compressor 1 runs at the tenth preset threshold reaches the eleventh preset threshold, the controller 20 controls the output and input currents of the DC-DC booster 19 to be 0, and then controls the DC-DC booster 19 to be turned off.

[0075] Specifically, in this embodiment, the eleventh preset threshold is 1.5 minutes; as a variation of this embodiment, the first preset threshold may also be 2 minutes.

[0076] P3. The controller 20 controls the air compressor 1, the inlet throttle valve 4 and the outlet throttle valve 5 to be closed.

[0077] P4. When the controller 20 calculates and determines that the average voltage value of the single battery is less than the twelfth preset threshold, the controller 20 controls the hydrogen circulation pump 14, the hydrogen discharge valve 16 and the water discharge valve 21 to close.

[0078] Specifically, in this embodiment, the twelfth preset threshold is 180 mV; as a variation of this embodiment, the twelfth preset threshold may also be 220 mV.

[0079] P5. The controller 20 controls the hydrogen inlet valve 12 and the proportional valve 13 to be closed.

[0080] P6. When the controller 20 determines that the temperature of the water in the fuel cell stack 17 is lower than the thirteenth preset threshold, the controller 20 controls the water pump 7 and the radiator 8 to be turned off.

[0081] Specifically, in this embodiment, the thirteenth preset threshold is 20°C; as a variation of this embodiment, the thirteenth preset threshold may also be 45°C.

[0082] In this document, the directional words such as front, back, top, and bottom are defined by the positions of the components in the drawings and the positions of the components relative to each other, and are only for the sake of clarity and convenience in expressing the technical solution. It should be understood that the use of the directional words should not limit the scope of protection claimed in this application.

[0083] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A hydrogen vehicle fuel cell system, characterized in that: Including fuel cell stack, air compressor, out-of-stack throttle valve, hydrogen cylinder, voltage inspection module and controller; The stack is provided with an air inlet, an air outlet, a hydrogen inlet, a hydrogen outlet, a hydrogen exhaust valve and a water exhaust valve; the stack outlet throttle valve is connected to the air outlet; The air compressor is connected to the fuel cell stack through the air inlet; a stack entry throttle valve is provided between the air compressor and the air inlet; the stack entry throttle valve is connected to the air compressor and the air inlet respectively; The hydrogen cylinder is connected to the fuel cell stack through the hydrogen inlet; a hydrogen inlet valve is provided between the hydrogen cylinder and the hydrogen inlet; the hydrogen inlet valve is connected to the hydrogen cylinder and the hydrogen inlet respectively; The controller is electrically connected to the air compressor, the stack entry throttle valve, the stack exit throttle valve, the stack entry hydrogen valve and the voltage inspection module respectively; the voltage inspection module is used to detect the voltage of each single cell in the battery stack; It also includes an intercooler; the intercooler is arranged between the air compressor and the air inlet; the air compressor is connected to the air inlet through the intercooler; It also includes a water tank and a water pump; the battery stack is also provided with a first water inlet and a first water outlet; the water tank is connected to the water inlet of the water pump through the intercooler; the water outlet of the water pump is connected to the first water inlet; the water outlet of the water pump is also connected to the water tank; the first water outlet is connected to the water inlet of the water pump; the water pump is electrically connected to the controller; It also includes a hydrogen circulation pump; the hydrogen circulation pump is electrically connected to the controller; the hydrogen circulation pump is communicated with the hydrogen outlet and the hydrogen inlet respectively; a one-way valve is arranged between the hydrogen circulation pump and the hydrogen inlet; the one-way valve is communicated with the hydrogen circulation pump and the hydrogen inlet respectively; the hydrogen circulation pump and the one-way valve cooperate to circulate the unreacted hydrogen in the fuel cell stack to the fuel cell stack through the hydrogen inlet.

2. The hydrogen automobile fuel cell system according to claim 1, characterized in that: It also includes a humidifier; the humidifier is arranged between the air compressor and the air inlet; the air compressor is connected to the air inlet through the humidifier; the stack outlet throttle valve is connected to the air outlet through the humidifier.

3. The hydrogen automobile fuel cell system according to claim 1, characterized in that: A pressure reducing valve is also provided between the hydrogen cylinder and the hydrogen valve for stack entry; the pressure reducing valve is communicated with the hydrogen cylinder and the hydrogen valve for stack entry, respectively.

4. The hydrogen automobile fuel cell system according to claim 1, characterized in that: A proportional valve is also provided between the hydrogen valve for entering the stack and the hydrogen inlet; the proportional valve is communicated with the hydrogen inlet and the hydrogen valve for entering the stack respectively; and the proportional valve is electrically connected with the controller.

5. A control method for a hydrogen vehicle fuel cell system as claimed in any one of claims 1 to 4, characterized in that: The steps include: S1. The voltage inspection module detects the voltage value of each single cell in the battery stack and sends it to the controller; S2, the controller determines whether the average voltage value of the single battery is less than a first preset threshold value, and determines whether the voltage difference value of the single battery is greater than a second preset threshold value; When the average voltage value of the single battery is less than the first preset threshold value, or the voltage difference value of the single battery is greater than the second preset threshold value, the controller controls the speed of the air compressor to increase to a third preset threshold value; S3. When the time that the air compressor runs at the third preset threshold reaches a fourth preset threshold, and the controller determines that the average voltage value of the single cell is less than the first preset threshold or the voltage difference of the single cell is greater than the second preset threshold, the controller controls the hydrogen automobile fuel cell system to stop working.

6. The control method of the hydrogen automobile fuel cell system according to claim 5, characterized in that: Before step S1, the method further includes a startup step of the hydrogen energy vehicle fuel cell system; the startup step is as follows: T1, the controller determines whether there is a fault in the circuit of the hydrogen energy vehicle fuel cell system; if there is a fault, enters the fault mode; if there is no fault, controls the water pump to start; T2, the controller controls the hydrogen discharge valve and the water discharge valve to be fully opened, and controls the hydrogen circulation pump to be turned on; T3, the controller controls the hydrogen inlet valve and the proportional valve to open; T4. When the opening time of the hydrogen inlet valve and the proportional valve reaches the fifth preset threshold, the controller controls the switching frequency of the hydrogen discharge valve to be the sixth preset value, and controls the switching frequency of the water discharge valve to be the seventh preset threshold; and then controls the inlet throttle valve and the air compressor to open.

7. The control method of the hydrogen automobile fuel cell system according to claim 5, characterized in that: A proportional valve is further provided between the hydrogen inlet valve and the hydrogen inlet; the proportional valve is communicated with the hydrogen inlet and the hydrogen inlet valve respectively; the proportional valve is electrically connected with the controller; In step S3, the controller controls the hydrogen automobile fuel cell system to stop working in the following steps: P1. The controller controls the input current of the DC-DC booster so that the average voltage of each single cell in the battery stack is maintained between 770-830mV; the controller controls the switching frequency of the hydrogen exhaust valve to the eighth preset threshold, and controls the switching frequency of the water drain valve to the ninth preset threshold, and then controls the speed of the air compressor to increase to the tenth preset threshold; P2. When the time for which the air compressor runs at the tenth preset threshold reaches the eleventh preset threshold, the controller controls the output and input currents of the DC-DC booster to be 0, and then controls the DC-DC booster to be turned off; P3, the controller controls the air compressor, the inlet throttle valve and the outlet throttle valve to be closed; P4. When the controller determines that the average voltage value of the single battery is less than the twelfth preset threshold value, the controller controls the hydrogen circulation pump, the hydrogen discharge valve and the water discharge valve to close; P5, the controller controls the hydrogen inlet valve and the proportional valve to close; P6. When the controller determines that the temperature of the water in the fuel cell stack is lower than the thirteenth preset threshold, the controller controls the water pump and the radiator to shut down.

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