A fuel cell system and a vehicle

Abstract

The present application relates to the technical field of fuel cell, in particular to a fuel cell system and a vehicle, the present application constructs fault-tolerance control, so that after the flowmeter failure, the way of directly giving up the judgment of air flowmeter is abandoned, and the pressure data and temperature data are used for judgment, so that the air system control can still be normally operated, the actual stack flow pressure is maintained in the target range, and the normal operation of the fuel cell is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell, in particular to a fuel cell system and a vehicle. BACKGROUND

[0002] Fuel cell is an electrochemical reaction device, hydrogen and oxygen react in two half-electrodes respectively to generate water, and chemical energy is converted into electrical energy, accompanied by efficiency loss and conversion into heat energy.

[0003] Fuel cell stack is composed of multiple fuel cell monomers in series according to the negative-positive-negative-positive repeating mode, and the adjacent two fuel cell monomers are isolated by bipolar plates. Hydrogen supply flow channel is formed on one side surface of the bipolar plate and contacts with the hydrogen reaction electrode, oxygen (air) supply flow channel is formed on the other side surface of the bipolar plate and contacts with the oxygen reaction electrode, and cooling liquid supply channel is formed in the middle of the bipolar plate. Different medium flow channels are sealed by sealing materials.

[0004] In engineering application, in order to meet the continuous and reliable output of electrical energy, the air flow and pressure entering the stack need to be accurately controlled, so that there is sufficient oxygen and sufficient contact reaction with the catalyst to ensure the continuous and stable output of electrical energy to the outside.

[0005] The actual flow of the flow meter and the actual pressure of the pressure sensor are collected, and the difference between the target value is calculated. The speed of the air compressor and the opening of the throttle valve are adjusted through PI closed loop to realize that the actual flow pressure entering the stack is continuously maintained in the target range. However, if the flow meter fails, the air system control will be unstable. In the existing scheme, the air system has no fault tolerance control for the flow meter failure, so that the flow meter needs to be urgently stopped for maintenance, which will reduce the service life of the engine. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a fuel cell system and a vehicle which can still operate normally after the flow meter fails by constructing fault-tolerant control.

[0007] In order to solve the above technical problems, the technical scheme adopted by the present application is:

[0008] A fuel cell system, comprising an air filter, an air flow meter, an air compressor, a pressure sensor, an environmental temperature sensor, a controller, a stack and a throttle valve.

[0009] The stack comprises an air inlet and an air outlet, and the air filter, the air flow meter, the air compressor, the pressure sensor and the air inlet are sequentially connected.

[0010] The throttle valve is connected with the air outlet.

[0011] The controller is electrically connected with the air filter, the air flow meter, the air compressor, the pressure sensor, the ambient temperature sensor, the electric pile and the throttle valve respectively;

[0012] The controller performs the following steps:

[0013] Step S1: Set the upper and lower limits of the air flow meter signal normal feedback as Q1 and Q2, set the minimum starting speed of the air compressor as rpm1, set the target flow of the electric pile as Q3, and set the target pressure as P1;

[0014] Step S2: Read the actual speed of the air compressor rpm2 and the start instruction of the electric pile;

[0015] Step S3: Determine whether the start instruction is received and the speed of the air compressor rpm2 is greater than or equal to rpm1, if yes, go to S4, if no, go to S2;

[0016] Step S4: Read the air flow meter feedback signal Q4;

[0017] Step S5: Determine whether Q1 is greater than or equal to Q4 and Q4 is greater than or equal to Q2, if yes, execute S6, otherwise execute S10;

[0018] Step S6: Read the actual pressure P2 at the outlet of the air compressor;

[0019] Step S7: Calculate the difference P3 between P2 and P1, and the difference Q5 between Q1 and Q4;

[0020] Step S8: Calculate the target speed of the air compressor and the target opening of the throttle valve according to the values of P3 and Q5 through PI adjustment;

[0021] Step S9: The air compressor and the throttle valve respond to the target speed and the opening, so that the pressure and the flow reach the target values;

[0022] Step S10: Read the actual pressure P2 at the outlet of the air compressor, the ambient temperature T1 and the atmospheric pressure P4;

[0023] Step S11: Calculate the pressure ratio P5 = P2 / P4 according to the actual pressure P2 and the atmospheric pressure P4;

[0024] Step S12: Obtain the real-time flow Q6 through P5, T1 and rpm2;

[0025] Step S13: Calculate the difference P3 between P2 and P1, and the difference Q5 between Q1 and Q6; go to S8;

[0026] Step S14: Determine whether the shutdown instruction is received, if yes, jump to step S15, otherwise jump to S2;

[0027] Step S15: End.

[0028] Further, the ambient temperature sensor is arranged on the air filter.

[0029] Further, the throttle valve is an electrically controlled throttle valve, and the controller controls the opening degree of the electrically controlled throttle valve.

[0030] Further, the step S12 further comprises: obtaining the real-time flow Q6 by P5, T1, rpm2 and the air compressor MAP chart.

[0031] To solve the above technical problems, another technical solution adopted by the present application is:

[0032] A vehicle comprising the fuel cell system.

[0033] The present application has the beneficial effect that: by constructing fault-tolerant control, after the flow meter fails, the way of directly giving up judging by the air flow meter is abandoned, and the pressure data and temperature data are used for judgment, so that the actual flow into the stack pressure can be maintained in the target range, and the normal operation of the fuel cell is realized. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A system diagram of a fuel cell system according to an embodiment of the present application;

[0035] Figure 2 A control flow chart of a fuel cell system according to an embodiment of the present application;

[0036] Figure 3 An air compressor MAP chart according to an embodiment of the present application (wherein the five left-to-right bending curves correspond to the five speeds 1-5). DETAILED DESCRIPTION

[0037] To explain the technical content, purposes and effects of the present application in detail, the following will be described in conjunction with the embodiments and the accompanying drawings.

[0038] Embodiment 1

[0039] Please refer to Figure 1 A fuel cell system comprising an air filter, an air flow meter, an air compressor, a pressure sensor, an ambient temperature sensor, a controller, an air stack and a throttle valve.

[0040] The air stack comprises an air inlet and an air outlet, and the air filter, the air flow meter, the air compressor and the pressure sensor are sequentially connected.

[0041] The throttle valve is connected with the air outlet.

[0042] The controller is electrically connected with the air filter, the air flow meter, the air compressor, the pressure sensor, the ambient temperature sensor, the electric pile and the air throttle respectively.

[0043] The ambient temperature sensor is arranged on the air filter.

[0044] The air throttle is an electric control air throttle, and the controller controls the opening degree of the electric control air throttle.

[0045] Embodiment two

[0046] Please refer to Figure 2 and Figure 3 , a fuel cell system, wherein the controller performs the following steps:

[0047] Step S1: set the upper and lower limits of the air flow meter signal normal feedback as Q1 and Q2, set the minimum starting speed of the air compressor as rpm1, set the target flow of the electric pile as Q3, and set the target pressure as P1;

[0048] Step S2: read the actual speed of the air compressor rpm2 and the start-up instruction of the electric pile;

[0049] Step S3: determine whether the start-up instruction is received and the speed of the air compressor rpm2 is greater than or equal to rpm1, if yes, go to S4, if no, go to S2;

[0050] Step S4: read the feedback signal Q4 of the air flow meter;

[0051] Step S5: determine whether Q1 is greater than or equal to Q4 and Q4 is greater than or equal to Q2, if yes, execute S6, otherwise execute S10;

[0052] Step S6: read the actual pressure P2 of the air compressor outlet;

[0053] Step S7: calculate the difference P3 between P2 and P1, and the difference Q5 between Q1 and Q4;

[0054] Step S8: calculate the target speed of the air compressor and the target opening degree of the air throttle according to the values of P3 and Q5 through PI adjustment;

[0055] Step S9: the air compressor and the air throttle respond to the target speed and the target opening degree, so that the pressure and the flow reach the target values;

[0056] Step S10: read the actual pressure P2 of the air compressor outlet, the ambient temperature T1 and the atmospheric pressure P4;

[0057] Step S11: calculate the pressure ratio P5 = P2 / P4 according to the actual pressure P2 and the atmospheric pressure P4;

[0058] Step S12: obtain the real-time flow Q6 by searching the MAP diagram of the air compressor through P5, T1 and rpm2 (refer to Figure 3 ).

[0059] Step S13: calculate P2 and P1 difference P3, Q1 and Q6 difference Q5; enter S8;

[0060] Step S14: determine whether to receive the shutdown instruction, if yes jump to step s15, otherwise jump to S2;

[0061] Step S15: end.

[0062] Example three

[0063] A vehicle comprising the fuel cell system of any one of example one or example two.

[0064] The above description is only examples of the present application, and does not limit the patent scope of the present application, any equivalent transformation using the content of the present application specification and drawings, or direct or indirect application in related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A fuel cell system characterized by comprising: The system comprises an air filter, an air flow meter, an air compressor, a pressure sensor, an ambient temperature sensor, a controller, an electric pile and a throttle valve. The electric pile comprises an air inlet and an air outlet, and the air filter, the air flow meter, the air compressor and the pressure sensor are sequentially connected with the air inlet. The throttle valve is connected with the air outlet. The controller is electrically connected with the air filter, the air flow meter, the air compressor, the pressure sensor, the ambient temperature sensor, the electric pile and the throttle valve. The controller performs the following steps: Step S1: setting the upper and lower limits of the normal feedback signal of the air flow meter as Q1 and Q2, setting the minimum starting speed of the air compressor as rpm1, setting the target flow of the electric pile as Q3 and the target pressure as P1; Step S2: reading the actual speed rpm2 of the air compressor and the starting instruction of the electric pile; Step S3: judging whether the starting instruction is received and whether the speed rpm2 of the air compressor is greater than or equal to rpm1, if yes, entering step S4, and if no, entering step S2; Step S4: reading the feedback signal Q4 of the air flow meter; Step S5: judging whether Q1 is greater than or equal to Q4 and whether Q4 is greater than or equal to Q2, if yes, executing step S6, and if no, executing step S10; Step S6: reading the actual pressure P2 of the outlet of the air compressor; Step S7: calculating the difference P3 between P2 and P1 and the difference Q5 between Q1 and Q4; Step S8: calculating the target speed of the air compressor and the target opening of the throttle valve according to the values of P3 and Q5 through PI adjustment; Step S9: the air compressor and the throttle valve responding to the target speed and the target opening so that the pressure and the flow reach the target values; Step S10: reading the actual pressure P2 of the outlet of the air compressor, the ambient temperature T1 and the atmospheric pressure P4; Step S11: calculating the pressure ratio P5 according to the actual pressure P2 and the atmospheric pressure P4, P5=P2 / P4; Step S12: obtaining the real-time flow Q6 through P5, T1 and rpm2; Step S13: calculating the difference P3 between P2 and P1 and the difference Q5 between Q1 and Q6; entering step S8; Step S14: judging whether the shutdown instruction is received, if yes, jumping to step S15, and if no, jumping to step S2; Step S15: ending.

2. The fuel cell system of claim 1, wherein The ambient temperature sensor is arranged on the air filter.

3. The fuel cell system of claim 1, wherein The throttle valve is an electric throttle valve, and the controller controls the opening of the electric throttle valve.

4. The fuel cell system of claim 1, wherein The step S12 further comprises: obtaining the real-time flow Q6 through the MAP diagram of the air compressor according to P5, T1 and rpm2.

5. A vehicle characterized by comprising: The fuel cell system of any one of claims 1-4.

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