阅读说明：本技术 燃料电池系统的控制方法、控制装置和燃料电池系统 (Control method and control device for fuel cell system, and fuel cell system ) 是由 马义 李学锐 熊成勇 张剑 李波 于 2021-06-10 设计创作，主要内容包括：本申请实施例提供了一种燃料电池系统的控制方法、控制装置和燃料电池系统,燃料电池系统的控制方法包括：响应于低功率作业请求；获取所述燃料电池系统的电压信息；基于所述电压信息,调节所述燃料电池系统的空气供给参数、燃料供给参数和排空阀的作业参数中的至少一者,以使所述燃料电池系统的电压信息低于第一阈值。该燃料电池系统的控制方法使得燃料电池系统在低功率作业的情况下,能够对燃料电池系统的电压进行控制,进而保障电堆质子交换膜的催化剂的使用寿命,提高燃料电池系统的电堆的使用寿命。(The embodiment of the application provides a control method and a control device of a fuel cell system and the fuel cell system, wherein the control method of the fuel cell system comprises the following steps: responding to a low-power job request; acquiring voltage information of the fuel cell system; based on the voltage information, adjusting at least one of an air supply parameter, a fuel supply parameter, and an operating parameter of an purge valve of the fuel cell system to bring the voltage information of the fuel cell system below a first threshold. The control method of the fuel cell system can control the voltage of the fuel cell system under the condition of low-power operation of the fuel cell system, thereby ensuring the service life of a catalyst of a proton exchange membrane of a galvanic pile and prolonging the service life of the galvanic pile of the fuel cell system.)

1. A control method of a fuel cell system, characterized by comprising:

responding to a low-power job request;

acquiring voltage information of the fuel cell system;

based on the voltage information, adjusting at least one of an air supply parameter, a fuel supply parameter, and an operating parameter of an purge valve of the fuel cell system to bring the voltage information of the fuel cell system below a first threshold.

2. The control method of a fuel cell system according to claim 1, wherein the step of acquiring voltage information of the fuel cell system includes:

and acquiring the single-cell voltage of the fuel cell stack of the fuel cell system.

3. The control method of a fuel cell system according to claim 2, wherein the step of adjusting an air supply parameter of the fuel cell system based on the voltage information includes:

in the case that the electric stack single-chip voltage is larger than the first threshold value, reducing the air inlet pressure and the air metering ratio of the fuel cell system, so that the air inlet pressure is smaller than a second threshold value, and the air metering ratio is smaller than a third threshold value;

the value of the first threshold is less than or equal to 0.85V, the value of the second threshold is greater than or equal to 100kPa and less than or equal to 120kPa, and the value of the third threshold is greater than or equal to 1.02 and less than 1.5.

4. The control method of a fuel cell system according to claim 2, wherein the step of adjusting a fuel supply parameter of the fuel cell system based on the voltage information includes:

reducing the fuel feed pressure of the fuel cell system and reducing the fuel metering ratio under the condition that the electric stack single sheet voltage is larger than a first threshold value, so that the fuel feed pressure is smaller than a fourth threshold value, and the fuel metering ratio is larger than a fifth threshold value;

the value of the first threshold is less than or equal to 0.85V, the value of the fourth threshold is greater than or equal to 102kPa and less than or equal to 120kPa, and the value of the fifth threshold is greater than or equal to 1 and less than 1.3.

5. The control method of a fuel cell system according to claim 2, wherein the step of adjusting an operation parameter of an purge valve of the fuel cell system based on the voltage information includes:

increasing the opening period of the evacuation valve and/or shortening the opening time of the evacuation valve in the case that the stack monolithic voltage is greater than a first threshold value;

wherein the value of the first threshold is less than or equal to 0.85V.

6. A control device of a fuel cell system, characterized by comprising:

a memory storing a computer program;

a processor executing the computer program;

wherein the processor implements the control method of the fuel cell system according to any one of claims 1 to 5 when executing the computer program.

7. A fuel cell system, characterized by comprising:

the fuel cell stack is communicated with an air input pipeline, an air output pipeline, a fuel input pipeline and a fuel output pipeline;

the air control assembly is arranged on the air input pipeline and the air output pipeline;

a fuel control assembly disposed in the fuel input line and the fuel output line;

the control device of claim 6, the control device being coupled to the air control assembly and the fuel control assembly, the control device being configured to:

adjusting, by the air control assembly, an air supply parameter of the fuel cell system; and/or

Adjusting, by the fuel control assembly, a fueling parameter of the fuel cell system; and/or

Adjusting an operating parameter of the purge valve.

8. The fuel cell system according to claim 7, further comprising:

and the voltage detection unit is connected to the galvanic pile and is used for detecting the galvanic pile single-chip voltage of the galvanic pile.

9. The fuel cell system of claim 7, wherein the air control assembly comprises:

the throttle valve is arranged on the air input pipeline;

the air compressor is arranged on the air input pipeline and is positioned between the throttle valve and the electric pile;

the flowmeter is arranged on the air input pipeline;

the back pressure valve is arranged on the air output pipeline;

one end of the pressure relief pipeline is connected to the air input pipeline, and the other end of the pressure relief pipeline is connected to the air output pipeline;

and the pressure relief valve is arranged on the pressure relief pipeline.

10. The fuel cell system of claim 7, wherein the fuel control assembly comprises:

the proportional valve is arranged on the fuel input pipeline;

the emptying valve is arranged on the fuel output pipeline;

the gas-liquid separator is arranged on the fuel output pipeline and is positioned between the emptying valve and the electric pile;

and one end of the circulating pipeline is communicated with the fuel input pipeline, and the other end of the circulating pipeline is communicated with the air outlet of the gas-liquid separator.

Technical Field

The invention relates to the technical field of batteries, in particular to a control method of a fuel cell system, a control device of the fuel cell system and the fuel cell system.

Background

The fuel cell system includes a stack, an air system, a hydrogen system, a cooling system, an electrical system, and respective control systems. The working conditions of the fuel cell system are divided into steady-state working conditions and dynamic working conditions, and the steady-state working conditions comprise 0 power output working conditions, namely idling working conditions. When the fuel cell system is started successfully, the whole vehicle does not issue a power instruction, or the whole vehicle stops temporarily due to a traffic light, at the moment, the fuel cell system operates under an idling working condition, and the net output power of the system to the whole vehicle is 0. If the output power of the fuel cell cannot be accurately controlled in an idle state, the internal voltage of the stack is increased under the condition of a certain current, so that the catalyst of the proton exchange membrane of the stack can be rapidly oxidized, platinum can easily form platinum oxide and platinum ions, the catalyst is irreversibly attenuated, and the service life of the stack can be rapidly reduced.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art or the related art.

In view of this, according to a first aspect of embodiments of the present application, there is provided a control method of a fuel cell system, including:

responding to a low-power job request;

acquiring voltage information of the fuel cell system;

based on the voltage information, adjusting at least one of an air supply parameter, a fuel supply parameter, and an operating parameter of an purge valve of the fuel cell system to bring the voltage information of the fuel cell system below a first threshold.

In a first possible implementation manner of the first aspect, the step of acquiring voltage information of the fuel cell system includes:

and acquiring the single-cell voltage of the fuel cell stack of the fuel cell system.

In a second possible implementation of the first aspect, the step of adjusting an air supply parameter of the fuel cell system based on the voltage information comprises:

in the case that the electric stack single-chip voltage is larger than a first threshold value, reducing the air inlet pressure and the air metering ratio of the fuel cell system, so that the air inlet pressure is smaller than a second threshold value, and the air metering ratio is smaller than a third threshold value;

the value of the first threshold is less than or equal to 0.85V, the value of the second threshold is greater than or equal to 100kPa and less than or equal to 120kPa, and the value of the third threshold is greater than or equal to 1.02 and less than 1.5.

In a third possible implementation of the first aspect, the step of adjusting a fuel supply parameter of the fuel cell system based on the voltage information comprises:

reducing the fuel feed pressure of the fuel cell system and reducing the fuel metering ratio under the condition that the electric stack single sheet voltage is larger than a first threshold value, so that the fuel feed pressure is smaller than a fourth threshold value, and the fuel metering ratio is larger than a fifth threshold value;

the value of the first threshold is less than or equal to 0.85V, the value of the fourth threshold is greater than or equal to 102kPa and less than or equal to 120kPa, and the value of the fifth threshold is greater than or equal to 1 and less than 1.3.

In a fourth possible embodiment of the first aspect, the step of adjusting an operating parameter of an purge valve of the fuel cell system based on the voltage information comprises:

increasing the opening period of the evacuation valve and/or shortening the opening time of the evacuation valve in the case that the stack monolithic voltage is greater than a first threshold value;

wherein the value of the first threshold is less than or equal to 0.85V.

According to a second aspect of embodiments of the present application, there is provided a control device of a fuel cell system, including:

a memory storing a computer program;

a processor executing the computer program;

wherein the processor implements the control method of the fuel cell system according to any one of the above-described technical aspects when executing the computer program.

According to a third aspect of embodiments of the present application, there is provided a fuel cell system including:

the fuel cell stack is communicated with an air input pipeline, an air output pipeline, a fuel input pipeline and a fuel output pipeline;

the air control assembly is arranged on the air input pipeline and the air output pipeline;

a fuel control assembly disposed in the fuel input line and the fuel output line;

the control device of the above technical solution, the control device is connected to the air control assembly and the fuel control assembly, and the control device is configured to:

adjusting, by the air control assembly, an air supply parameter of the fuel cell system; and/or

Adjusting, by the fuel control assembly, a fueling parameter of the fuel cell system; and/or

Adjusting an operating parameter of the purge valve.

In a first possible embodiment of the third aspect, the fuel cell system further includes:

and the voltage detection unit is connected to the galvanic pile and is used for detecting the galvanic pile single-chip voltage of the galvanic pile.

In a second possible embodiment of the third aspect, the air control assembly comprises:

the throttle valve is arranged on the air input pipeline;

the air compressor is arranged on the air input pipeline and is positioned between the throttle valve and the electric pile;

the flowmeter is arranged on the air input pipeline;

the back pressure valve is arranged on the air output pipeline;

one end of the pressure relief pipeline is connected to the air input pipeline, and the other end of the pressure relief pipeline is connected to the air output pipeline;

and the pressure relief valve is arranged on the pressure relief pipeline.

In a third possible embodiment of the third aspect, the fuel control assembly includes:

the proportional valve is arranged on the fuel input pipeline;

the emptying valve is arranged on the fuel output pipeline;

the gas-liquid separator is arranged on the fuel output pipeline and is positioned between the emptying valve and the electric pile;

and one end of the circulating pipeline is communicated with the fuel input pipeline, and the other end of the circulating pipeline is communicated with the air outlet of the gas-liquid separator.

Compared with the prior art, the invention at least comprises the following beneficial effects: when the fuel cell system needs to perform low-power operation, the control method of the fuel cell system provided by the invention can respond to the low-power operation request, further acquire the voltage information of the fuel cell system, and further adjust at least one of the air supply parameter, the fuel supply parameter and the operation parameter of the exhaust valve of the fuel cell system based on the voltage information, so that the voltage information of the fuel cell system is lower than the first threshold value. The voltage of the fuel cell system can be controlled under the condition of low-power operation of the fuel cell system, so that the service life of a catalyst of a proton exchange membrane of the cell stack is ensured, and the service life of the cell stack of the fuel cell system is prolonged.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a flowchart illustrating steps of a control method of a fuel cell system according to an embodiment of the present disclosure;

fig. 2 is a block diagram showing a configuration of a control device of a fuel cell system according to an embodiment of the present disclosure;

FIG. 3 is a schematic block diagram of a fuel cell system of an embodiment provided herein;

FIG. 4 is a graph of on-chip voltage versus current density for a fuel cell system according to an embodiment of the present disclosure;

fig. 5 is a flowchart illustrating steps of a method for controlling a fuel cell system according to an embodiment of the present disclosure.

Wherein, the correspondence between the reference numbers and the component names in fig. 2 and 3 is:

1 electric pile, 2 air input pipeline, 3 air output pipeline, 4 fuel input pipeline and 5 fuel output pipeline;

601 throttling valve, 602 air compressor, 603 flow meter, 604 back pressure valve, 605 pressure relief pipeline, 606 pressure relief valve, 607 first temperature and pressure sensor, 608 second temperature and pressure sensor, 701 proportional valve, 702 drain valve, 703 gas-liquid separator, 704 circulation pipeline, 705 hydrogen return pump, 706 first pressure sensor, 707 second pressure sensor;

200 control devices, 210 memory, 220 processor.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and detailed description. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

As shown in fig. 1, a first aspect of an embodiment of the present application proposes a control method of a fuel cell system, including:

step 101: responding to a low-power job request; when the vehicle needs to enter the idling state, the vehicle can send out a low-power operation request, and the low-power operation request can be responded after the low-power operation request is received.

Step 102: voltage information of the fuel cell system is acquired. After the fuel cell system enters the low-power operation mode, voltage information of the fuel cell system is obtained so as to monitor the electric pile of the fuel cell in public, and operation parameters of the fuel cell system can be conveniently regulated and controlled based on the voltage information.

Step 103: based on the voltage information, at least one of an air supply parameter, a fuel supply parameter, and an operating parameter of the purge valve of the fuel cell system is adjusted to bring the voltage information of the fuel cell system below a first threshold.

The control method of the fuel cell system according to this embodiment may further obtain the voltage information of the fuel cell system in response to the low power operation request when the fuel cell system needs to perform the low power operation, and further adjust at least one of the air supply parameter, the fuel supply parameter, and the operation parameter of the purge valve of the fuel cell system based on the voltage information so that the voltage information of the fuel cell system is lower than the first threshold. The voltage of the fuel cell system can be controlled under the condition of low-power operation of the fuel cell system, oxidation of a catalyst can be avoided or inhibited, the service life of the catalyst of the proton exchange membrane of the cell stack is further ensured, and the service life of the cell stack of the fuel cell system is prolonged.

It is understood that, in the case that the first voltage information is higher than the first threshold, it indicates that the voltage of the fuel cell system is high and the catalyst of the fuel cell system is at risk of being oxidized, and at least one of the air supply parameter, the fuel supply parameter and the operation parameter of the purge valve is adjusted, for example, the air supply amount and the supply rate may be reduced and/or the fuel supply amount and the supply rate may be reduced to reduce the raw material capable of participating in the fuel cell reaction, so as to reduce the voltage in the stack of the fuel cell system, so as to prevent the catalyst in the stack from being oxidized in a high voltage state. The opening period of the emptying valve can be prolonged, the frequency of the fuel tail gas discharged by the fuel cell system is reduced, the concentration of nitrogen in the galvanic pile can be increased, the reaction of the fuel cell is further inhibited, and the voltage in the galvanic pile of the fuel cell system can be reduced to prevent the catalyst in the galvanic pile from being oxidized under the high-voltage state.

It is understood that the voltage within the fuel cell system can be adjusted by adjusting at least one of the air supply parameter, the fuel supply parameter, and the operating parameter of the purge valve, with more parameters being adjusted having the better effect on inhibiting oxidation of the catalyst within the fuel cell system. For example, the simultaneous adjustment of the air supply parameter, the fuel supply parameter, and the operation parameter of the purge valve can suppress the oxidation of the catalyst in the fuel cell system to the maximum extent, and can improve the service life of the stack.

It will be appreciated that the fuel cell system includes a fuel outlet for discharging off-gas from the stack, and that the off-gas comprises nitrogen, hydrogen and water, wherein the nitrogen is present in the largest proportion, such as if the open period of the purge valve were extended, which would increase the nitrogen concentration in the stack.

In some examples, the step of acquiring voltage information of the fuel cell system includes: and acquiring the single-cell voltage of the fuel cell stack of the fuel cell system.

The voltage of a single electric pile sheet of the electric pile can be collected to be used as the voltage information of the fuel cell system; on one hand, the electric pile single-chip voltage of the electric pile is convenient to collect and obtain; on the other hand, the voltage of the stack single-chip can better represent the voltage environment of the catalyst of the stack proton exchange membrane, for example, when the voltage of the stack single-chip exceeds 0.85V, the catalyst of the stack proton exchange membrane can accelerate oxidation, so that the service life of the stack can be conveniently guaranteed by taking the voltage of the stack single-chip as the voltage information.

In some examples, the step of adjusting the air supply parameter of the fuel cell system based on the voltage information includes:

under the condition that the monolithic voltage of the electric pile is greater than a first threshold value, reducing the air inlet pressure and the air metering ratio of the fuel cell system, so that the air inlet pressure is less than a second threshold value, and the air metering ratio is less than a third threshold value;

wherein, the value of the first threshold is less than or equal to 0.85V, the value of the second threshold is greater than or equal to 100kPa, and is less than or equal to 120kPa, and the value of the third threshold is greater than or equal to 1.02, and is less than 1.5.

When the stack single-chip voltage is larger than the first threshold, the oxidation of the catalyst of the stack proton exchange membrane is possible to be accelerated, and at this time, the stack inlet pressure and the air metering ratio can be reduced to reduce the amount of air supplied to the fuel cell system, reduce the raw materials for participating in the fuel cell reaction, reduce the output power of the fuel cell system, further reduce the stack single-chip voltage, inhibit or avoid the oxidation of the catalyst of the stack proton exchange membrane, and improve the service life of the stack.

It can be understood that the air metering ratio refers to the ratio of the actual supply amount of air to the theoretical air usage amount of the fuel cell, and in the case that the fuel cell is in the non-low power operation mode, the air metering needs to be more than 1.5 in order to improve the efficiency of the fuel cell reaction, in the technical scheme, the air metering ratio is reduced to 1.02 to 1.5, the supply amount of air to the fuel cell system can be reduced, and the output power of the fuel cell system can be reduced; meanwhile, the fuel cell system can be maintained in an operation state, so that quick response is facilitated when the fuel cell system switches the operation mode, for example, when the vehicle waits for a signal lamp, the vehicle stops running and sends a low-power operation request, and when the vehicle passes through when the signal lamp runs, the fuel cell system is required to be in a power output working condition, and at the moment, the driving requirement of the vehicle can be quickly responded only by increasing the air stacking pressure and the air metering ratio.

It can be understood that, in the case that the fuel cell is in the non-low power operation mode, the air inlet pressure is usually maintained above 120kPa in order to improve the efficiency of the fuel cell reaction, and in this technical solution, the air inlet pressure is maintained between 100kPa and 120kPa, so that the supply amount of air to the fuel cell system can be reduced, and the output power of the fuel cell system can be reduced; meanwhile, the fuel cell system can be maintained in an operation state, and quick response is facilitated when the fuel cell system switches the operation mode.

In some examples, the value of the second threshold is between 100kPa and 101kPa, which may achieve an effect of better reducing the voltage of a single cell of the stack, and at the same time, may enable the fuel cell to be in an operating state, so as to facilitate a fast response.

In some examples, the step of adjusting a fueling parameter of the fuel cell system based on the voltage information comprises:

under the condition that the monolithic voltage of the electric pile is larger than a first threshold value, reducing the fuel inlet pressure of the fuel cell system, and reducing the fuel metering ratio, so that the fuel inlet pressure is smaller than a fourth threshold value, and the fuel metering ratio is larger than a fifth threshold value;

wherein, the value of the first threshold is less than or equal to 0.85V, the value of the fourth threshold is greater than or equal to 102kPa, and is less than or equal to 120kPa, and the value of the fifth threshold is greater than or equal to 1, and is less than or equal to 1.3.

When the voltage of the single electric pile sheet is larger than the first threshold value, the catalyst of the electric pile proton exchange membrane is possible to accelerate oxidation, at this time, the fuel inlet pressure and the fuel metering ratio can be reduced, so as to reduce the fuel quantity supplied to the fuel cell system, reduce the raw materials for participating in the fuel cell reaction, reduce the output power of the fuel cell system, further reduce the voltage of the single electric pile sheet, inhibit or avoid the oxidation of the catalyst of the electric pile proton exchange membrane, and improve the service life of the electric pile.

It can be understood that the fuel metering ratio refers to the ratio of the actual supply amount of fuel to the theoretical fuel consumption of the fuel cell, and in the case that the fuel cell is in the non-low power operation mode, the fuel metering needs to be more than 1.3 in order to improve the efficiency of the fuel cell reaction, in this technical scheme, the fuel metering ratio is reduced to 1.02 to 1.3, the supply amount of fuel to the fuel cell system can be reduced, and the output power of the fuel cell system can be reduced; meanwhile, the fuel cell system can be maintained in an operation state, so that quick response is facilitated when the fuel cell system switches the operation mode, for example, when the vehicle waits for a signal lamp, the vehicle stops running and sends a low-power operation request, and when the vehicle passes through when the signal lamp runs, the fuel cell system is required to be in a power output working condition, and at the moment, the driving requirement of the vehicle can be quickly responded only by increasing the fuel stacking pressure and the fuel metering ratio.

It can be understood that, in the case that the fuel cell is in the non-low power operation mode, the fuel inlet pressure is usually maintained above 125kPa in order to improve the efficiency of the fuel cell reaction, and in this technical solution, the fuel inlet pressure is maintained between 102kPa and 120kPa, so that the supply amount of the fuel to the fuel cell system can be reduced, and the output power of the fuel cell system can be reduced; meanwhile, the fuel cell system can be maintained in an operation state, and quick response is facilitated when the fuel cell system switches the operation mode.

In some examples, the value of the fourth threshold is between 102kPa and 105kPa, which may achieve an effect of better reducing the voltage of the stack, and at the same time, enable the fuel cell to be in an operating state, so as to facilitate a fast response.

In some examples, the step of adjusting an operating parameter of an exhaust valve of the fuel cell system based on the voltage information comprises:

under the condition that the voltage of the stack single chip is larger than a first threshold value, increasing the opening period of the exhaust valve and/or shortening the opening time of the exhaust valve;

wherein, the value of the first threshold is less than or equal to 0.85V.

Under the condition that the voltage of the electric pile single sheet is greater than the first threshold value, the catalyst of the electric pile proton exchange membrane is possible to accelerate oxidation, at the moment, the opening period of the emptying valve can be increased and/or the opening time of the emptying valve is shortened, so that the effective opening time of the emptying valve is reduced, more nitrogen can be accumulated in the electric pile, the reaction inside the fuel cell is inhibited, the output power of the fuel cell system is reduced, the voltage of the electric pile single sheet can be further reduced, the oxidation of the catalyst of the electric pile proton exchange membrane can be inhibited or avoided, and the service life of the electric pile can be prolonged.

As shown in fig. 2, according to a second aspect of the embodiment of the present application, there is provided a control apparatus 200 of a fuel cell system, including:

a memory 210 storing a computer program;

a processor 220 executing a computer program;

the processor 220 implements the control method of the fuel cell system according to any one of the above-described embodiments when executing the computer program.

Since the processor of the control device 200 for a fuel cell system according to the present application implements the control method for a fuel cell system according to any of the above-mentioned technical solutions when executing the computer program, the processor 220 has all the advantages of the control method for a fuel cell system, and will not be described herein again.

As shown in fig. 3, according to a third aspect of the embodiments of the present application, there is provided a fuel cell system including: the fuel cell stack comprises a fuel cell stack 1, wherein the fuel cell stack 1 is communicated with an air input pipeline 2, an air output pipeline 3, a fuel input pipeline 4 and a fuel output pipeline 5; the air control assembly is arranged on the air input pipeline 2 and the air output pipeline 3; a fuel control assembly disposed in the fuel input line 4 and the fuel output line 5; in the control device 200 according to the above-mentioned technical solution, the control device 200 is connected to the air control assembly and the fuel control assembly, and the control device 200 is configured to: adjusting an air supply parameter of the fuel cell system by the air control assembly; and/or by the fuel control assembly, adjust the fuel supply parameters of the fuel cell system and/or the operating parameters of the purge valve 702.

The fuel cell system according to the embodiment of the present application includes the control device 200 according to the above-described aspect, and therefore the fuel cell system has all the advantageous effects of the control device 200 of the fuel cell system.

The fuel cell system provided by the embodiment of the application comprises a stack 1, an air control assembly and a fuel control assembly.

The air control components are arranged on the air input pipeline 2 and the air output pipeline 3, so that the supply quantity of air, the stack entering pressure of air and the air metering ratio can be controlled, and when the voltage value of the stack single chip is too high, the control device 200 is only needed to adjust the air control components to reduce the supply quantity of air, so that the voltage of the stack single chip is greatly reduced, and the oxidation of the catalyst of the proton exchange membrane of the stack 1 is avoided or inhibited.

By arranging the fuel control components on the fuel input pipeline 4 and the fuel output pipeline 5, the supply amount of fuel, the fuel inlet pressure and the fuel metering ratio can be controlled, and the opening period and/or the opening time of the emptying valve 702 can be controlled, so that when the voltage value of the electric pile single plate is overhigh, the supply amount of the fuel can be reduced only by adjusting the fuel control components by the control device 200, the electric pile single plate voltage can be greatly reduced, and the oxidation of the catalyst of the proton exchange membrane of the electric pile 1 can be avoided or inhibited.

In some examples, the fuel cell system further includes: and the voltage detection unit is connected to the electric pile 1 and used for detecting the electric pile single-chip voltage of the electric pile 1.

The fuel cell system includes a voltage detection unit capable of detecting a stack individual voltage of the stack 1, and the control device 200 is communicatively connected to the voltage detection unit to obtain voltage information of the fuel cell system.

In some examples, an air control assembly includes: a throttle valve 601 provided on the air input line 2; the air compressor 602 is arranged on the air input pipeline 2 and is positioned between the throttle valve 601 and the electric pile 1; a flow meter 603 provided on the air input line 2; a back pressure valve 604 provided on the air output line 3; a pressure relief pipeline 605 having one end connected to the air input pipeline 2 and the other end connected to the air output pipeline 3; and a pressure relief valve 606 provided on the pressure relief line 605.

The air control assembly includes: the throttle valve 601, the air compressor 602 and the back pressure valve 604, the throttle valve 601 and the air compressor 602 are arranged on the air input pipeline 2, the control device 200 is connected with the throttle valve 601 and the air compressor 602, and the air feeding pressure and the air metering ratio can be reduced by only reducing the opening degree of the throttle valve 601 or reducing the rotating speed of the air compressor 602. The back pressure valve 604 is arranged on the air output pipeline 3, and the opening period of the back pressure valve 604 is adjusted or the opening degree of the back pressure valve 604 is reduced, so that the speed of air flowing through the electric pile 1 can be reduced, the supply amount of air can be reduced, and the pile inlet pressure and the air metering ratio can be reduced.

The air control assembly further includes: the pressure relief valve 606 and the pressure relief pipeline 605 can also slow down the rate of air flowing through the cell stack 1 under the condition of reducing the opening degree of the back pressure valve 604 and/or reducing the opening time of the back pressure valve 604, so that the supply amount of air can be reduced, and the stack inlet pressure and the air metering ratio can be reduced.

The air control assembly further includes: the flowmeter 603 can count the air quantity input into the galvanic pile 1 through the setting of the flowmeter 603, and the flowmeter 603 is connected to the controller, so that the accurate air supply parameters are facilitated.

As shown in fig. 3, in some examples, the air control assembly may further include: a first temperature and pressure sensor 607 and a second temperature and pressure sensor 608, wherein the first temperature and pressure sensor 607 is arranged on the air input pipeline 2 to detect the temperature of the air supplied into the electric pile 1, and the second temperature and pressure sensor 608 is arranged on the air output pipeline 3 to detect the temperature of the air exhausted by the electric pile 1, which is beneficial to monitoring the operation state of the electric pile 1 and ensures that the fuel cell system is used more safely.

As shown in FIG. 3, in some examples, the fuel control assembly includes: a proportional valve 701 provided on the fuel input line 4; an evacuation valve 702 provided on the fuel outlet line 5; a gas-liquid separator 703 provided on the fuel output line 5 between the purge valve 702 and the stack 1; one end of the circulation line 704 is connected to the fuel supply line 4, and the other end is connected to the outlet of the gas-liquid separator 703.

The fuel control assembly includes: a proportional valve 701 and an exhaust valve 702, wherein the proportional valve 701 is arranged on the fuel output pipeline 5, the proportional valve 701 can be connected to the control device 200, and the control device 200 reduces the opening degree of the proportional valve 701, namely, the supply quantity of the fuel can be reduced so as to reduce the voltage of the single cell of the electric pile; the evacuation valve 702 is arranged on the fuel output pipeline 5, and more nitrogen gas can be accumulated in the electric pile 1 by reducing the opening time of the evacuation valve 702, so that the reaction of the fuel cell can be inhibited, and the electric pile single-chip voltage can be greatly reduced.

The fuel control assembly includes: the gas-liquid separator 703 and the circulation line 704 are provided to separate gas and liquid from the substance output through the fuel output line 5, the separated liquid may be discharged through the purge valve 702, and the separated hydrogen may be returned to the stack 1 through the circulation line 704, which may improve fuel efficiency.

As shown in fig. 3, in some examples, in order to facilitate the recycling of the hydrogen gas, a hydrogen return pump 705 may be provided on the circulation line 704 to supply the hydrogen gas separated by the gas-liquid separator 703 into the stack 1.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The present embodiment provides a fuel cell system as shown in fig. 3, which includes a stack 1, an air control assembly, a fuel control assembly, and a control device 200, wherein the air control assembly includes a throttle valve 601, an air compressor 602, a pressure relief valve 606, a flow meter 603, a first temperature and pressure sensor 607, a second temperature and pressure sensor 608, and a back pressure valve 604. The air system airflow direction is: the system comprises a throttle valve 601, an air compressor 602, a flowmeter 603, a first temperature and pressure sensor 607, a galvanic pile 1, a second temperature and pressure sensor 608 and a back pressure valve 604, wherein when a pressure release valve 606 is opened, a part of air enters the pressure release valve 606 and then enters the back pressure valve 604. The fuel control assembly comprises a proportional valve 701, a first pressure sensor 706, a second pressure sensor 707, a gas-liquid separator 703, a hydrogen return pump 705 and an emptying valve 702. The gas flow direction of the hydrogen system is as follows: when the emptying valve 702 is opened, the liquid water and part of nitrogen impurities separated by the gas-liquid separator 703 are discharged from the emptying valve 702.

The throttle valve 601 is located at an inlet of the air compressor 602, and is used for achieving air throttling, reducing the stack entering pressure of air to be near the atmospheric pressure, such as 90-100 kPa, the air compressor 602 provides required air flow for the electric stack 1, the flow meter 603 detects the stack entering air flow, the air compressor 602 and the backpressure valve 604 jointly achieve air flow and pressure regulation, when surplus air needs to be bypassed, the pressure release valve 606 is opened to release pressure and flow, and the first temperature and pressure sensor 607 and the second temperature and pressure sensor 608 are used for detecting the temperature and pressure of the air entering the stack and the temperature and pressure of the air exiting the stack. The hydrogen system proportional valve 701 is used for adjusting the hydrogen inlet flow rate, the first pressure sensor 706 and the second pressure sensor 707 are used for detecting the pressure of the hydrogen in the reactor and out of the reactor, the gas-liquid separator 703 is used for separating liquid water in the hydrogen, and the liquid water returns to the hydrogen pump 705 to realize hydrogen recycling. The emptying valve 702 is used for regularly discharging liquid water and nitrogen impurity gas in hydrogen, under the same operation condition of the galvanic pile 1, when the opening frequency of the emptying valve 702 is proper, the liquid water in the hydrogen can be completely discharged, meanwhile, more nitrogen impurities can be discharged, the concentration of the hydrogen entering the galvanic pile can be controlled to be more than 95%, when the opening frequency of the emptying valve 702 is lower, the discharged liquid water and nitrogen impurities are less, the concentration of the hydrogen entering the galvanic pile is lower than 95%, when the opening frequency of the emptying valve 702 is higher, the discharged liquid water and nitrogen impurities are more, the concentration of the hydrogen entering the galvanic pile can reach more than 95%, but a large amount of hydrogen can be discharged into the atmosphere to be wasted, and the hydrogen utilization rate is reduced.

The galvanic pile 1 realizes the chemical reaction of hydrogen and oxygen and outputs electric energy, and simultaneously feeds back a single-chip voltage value to the control device 200, the polarization curve of the galvanic pile 1 is shown in figure 2, when the running current of the galvanic pile 1 is near I1, the single-chip voltage of the galvanic pile 1 is limited by more than 0.85V, the attenuation rate of the galvanic pile 1 is greatly increased, and the I1 current is generally 0.01-0.05A/cm ^ 2.

The control device 200 realizes signal detection of each sensor and actuator and control of the actuator, switch and the like, an air metering ratio real-time calculation program is arranged in the controller, the air metering ratio is obtained according to the ratio of the flow value fed back by the air flow meter 603 and the theoretical air consumption value required by the current, and the metering ratio calculation value is corrected by combining the parameters of the air stack entering temperature, the air stack entering pressure and the like. And (3) a real-time calculation program of the hydrogen metering ratio, wherein the hydrogen pile feeding flow is calculated according to the opening degree of a proportional valve 701, the rotating speed of a hydrogen pump and the inlet and outlet pressure values of the hydrogen pump, the hydrogen metering ratio is obtained by the ratio of the hydrogen pile feeding flow to the theoretical hydrogen consumption value required by the current, and the calculated value of the metering ratio is corrected by combining the parameters such as the hydrogen pile feeding temperature and the pressure.

The specific implementation method comprises the following steps:

as shown in fig. 5, the control method of the fuel cell system is as follows:

step 301: determining whether a low power operation request is received, if yes, performing step 302, and if no, performing step 308;

step 302: responding to a low-power job request;

step 303: setting a stack current I1;

step 304: adjusting an air control assembly such that the air stack pressure is less than a second threshold and the air metering ratio is less than a third threshold;

step 305: adjusting a fuel control assembly such that the fuel in-stack pressure is less than a fourth threshold and the fuel metering ratio is greater than a fifth threshold;

step 306: adjusting the operation parameters of the evacuation valve, and increasing the opening period of the evacuation valve and/or shortening the opening time of the evacuation valve;

step 307: judging whether the voltage of the single cell of the galvanic pile is larger than a first threshold value, if so, executing a step 306, and if not, ending;

step 308: in response to the power demand.

When the output power required by the whole vehicle or the load on the fuel cell system is larger than the minimum operation power, the current of the electric pile 1 and the subsystem parameters are adjusted by the control device 200 to respond to the system required output power.

As shown in fig. 4, in the low power operation mode of the fuel cell, if the stack current is constant, the higher the power of the fuel cell system, the higher the voltage, for example, if the voltage at V1 is higher than 0.85V in fig. 1, the higher the probability of causing the catalyst of the stack proton exchange membrane to be oxidized rapidly, and if the voltage at V2 is lower than 0.85V, the probability of oxidizing the catalyst of the stack proton exchange membrane is low.

When the required output power of the fuel cell system is the minimum operation power, the control device 200 is used for setting the stack current I1, simultaneously adjusting air system parameters, controlling the air compressor 602 to operate at the lowest rotation speed in an idling mode, adjusting the opening degrees of the throttle valve 601, the backpressure valve 604 and the pressure release valve 606, controlling the stack inlet pressure of air to be 100-101kPa at the ultralow value, and controlling the air metering ratio to be 1.02-1.05. And adjusting parameters of a hydrogen system, namely the opening degree of a proportional valve 701 and the rotating speed of a hydrogen pump 24, controlling the minimum value of the pressure of hydrogen entering a reactor to be 102-105 kPa, and controlling the metering ratio of hydrogen to be 1-1.3. At this time, as shown in fig. 4, the stack single-chip voltage gradually decreases from V1 to approach V2, then the opening frequency of the evacuation valve 702 is decreased, that is, the opening period is increased, the opening duration is decreased, and the concentration of hydrogen entering the stack is decreased until the stack single-chip voltage decreases to V2 (less than 0.85V), and the frequency of the evacuation valve 702 is controlled to keep the stack single-chip voltage around V2 all the time, and the positive-negative deviation is less than 0.005V, so that the operating power of the stack 1 in this state reaches the minimum value, which is around 0.5 to 1 kW.

The control air inlet pressure is far less than the normal operation value of 120kPa, and the control air metering ratio is far less than the normal operation value of 1.5, so as to reduce the chemical reaction rate inside the electric pile 1 by reducing the oxygen partial pressure, thereby reducing the electric pile single sheet voltage value.

The hydrogen feed pressure is controlled to be much less than the normal operation value of 125kPa, so as to reduce the internal chemical reaction rate of the electric pile 1 by reducing the hydrogen partial pressure, thereby reducing the electric pile single sheet voltage value.

The hydrogen metering ratio is controlled to be far larger than the normal running value of 1.3, the frequency of the control emptying valve 702 is reduced, the nitrogen concentration of hydrogen entering the reactor is improved, nitrogen in the hydrogen comes from air side permeation, and the improvement of the nitrogen concentration of the hydrogen entering the reactor reduces the chemical reaction rate in the reactor 1, so that the monolithic voltage value of the reactor is greatly reduced.

In the description of the present invention, the terms "plurality" or "a plurality" refer to two or more, and unless otherwise specifically limited, the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are merely for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention; the terms "connected," "mounted," "secured," and the like are to be construed broadly and include, for example, fixed connections, removable connections, or integral connections; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In the present invention, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.