A hydrogen fuel cell startup failure and shutdown protection system and method

Abstract

The present invention relates to the field of new energy vehicles, and discloses a hydrogen fuel cell startup failure and shutdown protection system and method. The system comprises an MCU controller, an FCU controller, an air system, a hydrogen system, a hydrothermal system and an electrical system; the air system, the hydrogen system and the hydrothermal system are all connected to a fuel cell stack through pipelines; the FCU controller is used to control the switching actions of the air system, the hydrogen system and the hydrothermal system; the electrical system is used to power the MCU controller, the FCU controller, the air system, the hydrogen system and the hydrothermal system; the method comprises four modes, and the present invention provides a complete shutdown system and method for use during on-board use, so that the system can be quickly, stably and safely shut down at any time and in any state of the system, which can effectively protect the safety of the equipment body, ensure the safety of other equipment and facilities, and operators, and at the same time have good rapid performance.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicles, and in particular to a hydrogen fuel cell startup failure and shutdown protection system and method. Background Art

[0002] As a vehicle-mounted new energy power supply system or battery energy storage system, the hydrogen fuel cell system uses the battery stack to make hydrogen and oxygen in the air undergo an electrochemical reaction under the action of a catalyst, and forms an electric current through electron transfer, providing electrical energy as the driving energy of the vehicle, and can be used as an energy storage energy source. Hydrogen fuel cell systems are often used as power systems on vehicles or as part of energy storage conversion systems. In actual use, the hydrogen fuel system is required to have good safety, stability, and speed when the main body or related parts fail or are normally shut down. Summary of the invention

[0003] The purpose of the present invention is to provide a hydrogen fuel cell startup failure and shutdown protection to solve the technical problems of unstable, insensitive and unsafe shutdown of the hydrogen fuel cell system in an emergency situation.

[0004] Specifically, the present invention provides a hydrogen fuel cell startup failure and shutdown protection system, comprising:

[0005] MCU controller, FCU controller, air system, hydrogen system, hydrothermal system and electrical system;

[0006] The air system, hydrogen system, and water heat system are all connected to the fuel cell stack through pipelines;

[0007] The MCU controller is used to control the FCU controller;

[0008] The FCU controller is used to control the on / off actions of the air system, hydrogen system, and water heating system;

[0009] The electrical system is used to supply power to the MCU controller, FCU controller, air system, hydrogen system, and hydrothermal system.

[0010] A hydrogen fuel cell startup failure and shutdown protection method is applied to the system, and the method includes four shutdown protection modes, namely: a first mode, a second mode, a third mode and a fourth mode;

[0011] The first mode is the fast mode, the second mode is the emergency shutdown mode, the third mode is the air compressor shutdown mode, and the fourth mode is the purge shutdown mode; among them, in the first mode, the air system, hydrogen system, hydrothermal system, and electrical system are all in the closed state.

[0012] The beneficial effects provided by the present invention are:

[0013] 1. According to the current state of the fuel cell system, the shutdown process is entered through different paths, which can reduce the shutdown time and protect the system to prevent the system from containing water for a long time, resulting in chronic attenuation of the proton exchange membrane.

[0014] 2. It can ensure that the anode side is under positive pressure, preventing air from entering the anode side, causing a counter-polarity phenomenon and causing damage to the proton membrane.

[0015] 3. Make the shutdown process smooth to avoid exceeding the maximum pressure ratio of the air compressor and abnormal vibration caused by instability during dynamic changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the system structure of the present invention. DETAILED DESCRIPTION

[0017] 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.

[0018] Before formally describing the present invention, the scheme of the present invention is first generally described for easy understanding.

[0019] Please refer to Figure 1 The present invention provides a hydrogen fuel cell startup failure and shutdown protection system, comprising the following:

[0020] MCU controller, FCU controller, air system, hydrogen system, hydrothermal system and electrical system;

[0021] The air system, hydrogen system, and water heat system are all connected to the fuel cell stack through pipelines;

[0022] The MCU controller is used to control the FCU controller;

[0023] The FCU controller is used to control the on / off actions of the air system, hydrogen system, and water heating system;

[0024] The electrical system is used to supply power to the MCU controller, FCU controller, air system, hydrogen system, and hydrothermal system.

[0025] It should be noted that the air system includes: an air compressor, a bypass valve, an intake valve and an exhaust valve; one end of the air compressor is connected to the air pipe, and the other end is connected to one end of the intake valve and one end of the bypass valve; the other end of the intake valve is connected to one end of the fuel cell stack; the other end of the fuel cell stack is connected to one end of the exhaust valve; the other end of the exhaust valve is connected to the tail exhaust pipe; and the other end of the bypass valve is connected to the tail exhaust pipe.

[0026] It should be noted that the hydrogen system includes: an intake valve, a proportional valve and an exhaust and drain valve; one end of the intake valve is connected to the hydrogen pipeline, and the other end is connected to one end of the proportional valve; the other end of the proportional valve is connected to one end of the fuel cell stack; the other end of the fuel cell stack is connected to one end of the hydrogen exhaust and drain valve; the other end of the hydrogen exhaust and drain valve is connected to the tail exhaust pipe.

[0027] It should be noted that the hydrothermal system includes: a water pump, a three-way valve and a heat dissipation system; one end of the water pump is connected to the heat dissipation system through a water circuit to form a water circulation, and the other end is connected to the fuel cell stack; the other end of the fuel cell stack is connected to the first end of the three-way valve; the second end of the three-way valve is connected to one end of the water pump; and the third end of the three-way valve is connected to the heat dissipation system.

[0028] It should be noted that, in addition to the main units, the system of the present invention also has many sensors. In the air system, there are working temperature sensors and working pressure sensors. There are also working pressure sensors in the hydrogen system. The hydrothermal system contains temperature sensors and working pressure sensors.

[0029] Embodiment 1

[0030] The description of each component in the system of the present invention is as follows:

[0031] Air compressor: provides the system with the air required for reaction, and is also a tool for drying the water generated in the system.

[0032] Air bypass valve: allows the air compressed by the air compressor to enter the tail exhaust directly, without entering the fuel cell stack that reacts with hydrogen. The tail exhaust and hydrogen drain valves are shared by the hydrogen line. The air compressed by the air compressor can reduce the hydrogen concentration in the tail exhaust (safety)

[0033] Air intake valve and air exhaust valve: located in front and behind the fuel cell stack respectively, which can allow air to enter or prevent air from entering the fuel cell stack.

[0034] Hydrogen inlet valve: The valve that opens and closes the hydrogen inlet of the system to determine whether hydrogen enters the system.

[0035] Proportional valve: ensures that the system operates under the required pressure.

[0036] Hydrogen drain valve: discharges the generated water and impurity gas out of the system.

[0037] Water pump: A water circulation power pump that can ensure the normal circulation of water within the system and ensure the working pressure of the water.

[0038] Three-way valve: can make the system go through a small cycle or a large cycle. The small cycle directly passes through the PTC and enters the water pump, while the large cycle needs to pass through the cooling system before entering the water pump.

[0039] When the fuel cell system is working, the FCCU receives startup and shutdown commands from the external MCU controller, and the fuel cell feeds back the current working status to the FCU, such as starting, working, shutting down, fault status and other basic information. The MCU collects this information and sends a work request (critical, power on, etc.) to the fuel cell based on actual work needs.

[0040] A hydrogen fuel cell startup failure and shutdown protection method, applied to the system, the method includes four shutdown protection modes, namely: a first mode, a second mode, a third mode and a fourth mode;

[0041] The first mode is the fast mode, the second mode is the emergency shutdown mode, the third mode is the air compressor shutdown mode, and the fourth mode is the purge shutdown mode; among them, in the first mode, the air system, hydrogen system, hydrothermal system, and electrical system are all in the closed state.

[0042] Embodiment 2

[0043] The first mode is denoted by C1 and is described as follows:

[0044] Air system: air compressor speed is 0, bypass valve opening is 0, intake valve opening is 0, exhaust valve opening is 0

[0045] Hydrogen system: hydrogen inlet valve opening is 0, proportional valve closed is 0, hydrogen discharge valve closed is 0

[0046] Hydrothermal system: The water pump speed is set to 0 and the three-way valve opening is 0 (large circulation state).

[0047] Electrical system: Off mode

[0048] This mode is a fast mode that can quickly shut down the system in cases such as valve failure, failure of parts or the air compressor body not starting, etc. It can also solve the situation where the system needs to be shut down right after startup due to failure of other systems (non-fuel cell system).

[0049] Then enter and wait for the next startup.

[0050] The second mode is denoted as C2, and is as follows:

[0051] This mode is an emergency shutdown. When the system encounters a serious accident or major parts are damaged and needs to be shut down immediately, all valves need to be opened to relieve the pressure of the entire system and close the front-end air supply valve to prevent secondary injuries and protect the safety of personnel and other parts.

[0052] The C2 execution command is as follows:

[0053] Phase 1:

[0054] Air system: air compressor speed is 0, bypass valve opening is 100, intake valve opening is 100, exhaust valve opening is 100;

[0055] Hydrogen system: the opening of the hydrogen inlet valve is 0, the proportional valve is closed to 0, and the opening of the hydrogen discharge valve is 100;

[0056] Hydrothermal system: The water pump speed is set to 0 and the three-way valve opening is 0 (large circulation state).

[0057] Electrical system: Discharge mode until the system voltage drops below 36V, then enters shutdown mode.

[0058] The second stage: When the air compressor speed is 0, the proportional valve is closed to 0, and the hydrogen inlet valve is closed to 0, enter the execution operation:

[0059] Air system: air compressor speed is 0, bypass valve opening is 0, intake valve opening is 0, exhaust valve opening is 0

[0060] Hydrogen system: hydrogen inlet valve opening is 0, proportional valve closed is 0, hydrogen discharge valve closed is 0

[0061] Hydrothermal system: The water pump speed is set to 0 and the three-way valve opening is 0 (large circulation state).

[0062] Electrical system: Discharge mode until the system voltage drops below 36V, then enter shutdown mode

[0063] Then it is recommended to check the cause of the fault, cut off the power and wait for the next startup.

[0064] The third mode is denoted as C3, and is as follows:

[0065] In this mode, the air compressor is actually started, but has not yet started to draw current, so only a very small amount of water will be generated. The following process can prevent abnormal vibration of the air compressor shutdown and the risk of voltage caused by a trace amount of hydrogen remaining in the fuel cell stack (the air compressor is already working, air (oxygen) has entered, and voltage is generated).

[0066] Phase 1:

[0067] Air system: First, the air compressor speed remains unchanged, and the bypass valve opening is 100. The intake valve opening is 100, and the exhaust valve opening is 100;

[0068] Hydrogen system: the opening of the hydrogen inlet valve is 100, the proportional valve works normally, and the hydrogen discharge valve is 100;

[0069] Hydrothermal system: The water pump speed setting remains unchanged and the three-way valve opening is 0 (large circulation state).

[0070] Electrical system: DCDC working mode, normal load according to the original current.

[0071] Phase 2:

[0072] When the bypass valve opening is ≥90%, enter the following operation:

[0073] Air system: When the bypass valve opening is ≥90%, the air compressor speed is 0.

[0074] Hydrogen system: the hydrogen inlet valve opening is 100, the proportional valve works normally, and the hydrogen discharge valve is opened to 0;

[0075] Hydrothermal system: The water pump speed is set to 1200 rpm and the three-way valve opening is 0 (large circulation state).

[0076] Electrical system: Discharge mode until the system voltage drops below 36V, then enters shutdown mode.

[0077] Phase 3:

[0078] When the air compressor speed is 0 and the voltage drops below 36V, enter the following operation:

[0079] Air system: Bypass valve opening is 0. Inlet valve opening is 0, exhaust valve opening is 0.

[0080] Hydrogen system: hydrogen inlet valve opening is 0, proportional valve is closed, hydrogen discharge valve is opened to 0

[0081] Hydrothermal system: The water pump speed is set to 0 rpm and the three-way valve opening is 0 (large circulation state).

[0082] Electrical system: Off mode.

[0083] Wait for the reboot.

[0084] The fourth mode is denoted as C4, and is as follows:

[0085] The first stage: high-speed purge stage

[0086] Air system: The air compressor speed is changed to the designed purge speed (usually about 70% of the maximum speed), and the bypass valve opening is 0. The intake valve opening is 100, and the exhaust valve opening is 100.

[0087] Hydrogen system: the hydrogen inlet valve is opened to 100%, the proportional valve works normally (meeting the three-chamber pressure difference requirement), and the hydrogen discharge valve is opened to 100;

[0088] Hydrothermal system: The water pump speed is set to the purge speed at the beginning of the design (to meet the three-chamber pressure difference requirements), and the three-way valve opening is 0 (large circulation state).

[0089] Electrical system: DCDC working mode, drawing small current (make sure it does not exceed the allowed working voltage of the battery stack).

[0090] It should be noted that when the fuel cell system is working, under relevant working conditions, the smaller the current, the maximum voltage and the smaller the power.

[0091] Stage 2: When the low-speed purge time requirement is met (usually 15-30S), proceed to the following operations:

[0092] Air system: The bypass valve is opened to 100 degrees, and the air compressor speed is reduced to the low purge speed designed at the beginning (usually about 40% of the maximum speed). The intake valve opening is 100 degrees, and the exhaust valve opening is 100 degrees.

[0093] Hydrogen system: the hydrogen inlet valve is opened to 100%, the proportional valve works normally, and the hydrogen discharge valve is opened to 100

[0094] Hydrothermal system: The water pump speed is set to 1200 rpm (design speed), and the three-way valve opening is 0 (large circulation state).

[0095] Electrical system: DCDC working mode, drawing small current (make sure it does not exceed the allowed working voltage of the battery stack).

[0096] It should be noted that both stages of purging are intended to blow out all the water.

[0097] Stage 3: When the low-power purge time requirement is met (usually 10-20 seconds), the following operations are performed:

[0098] Air system: The bypass valve is opened to 100, and the air compressor speed is reduced to the minimum operating speed (generally 30,000 rpm). The intake valve opening is 0, and the exhaust valve opening is 0.

[0099] Hydrogen system: The hydrogen inlet valve is opened to 100, the proportional valve works normally (the minimum pressure is set to 0.2), and the hydrogen discharge valve is opened to 100

[0100] Hydrothermal system: The water pump speed is set to the lowest allowable speed, and the three-way valve opening is 0 (large circulation state).

[0101] Electrical system: Discharge mode until the system voltage drops below 36V, then enter shutdown mode

[0102] Phase 4:

[0103] Air system: When the voltage drops below 36V, enter the following operation:

[0104] Air system: The air compressor is at the lowest speed, and the bypass valve opening is 100. The intake valve opening is 0, and the exhaust valve opening is 0.

[0105] Hydrogen system: The opening of the hydrogen inlet valve is 100, the proportional valve works normally (set to 0.2), and the hydrogen discharge valve is closed.

[0106] Hydrothermal system: The water pump speed is set to 0 rpm and the three-way valve opening is 0 (large circulation state).

[0107] Electrical system: Off mode.

[0108] Phase 5:

[0109] Air system: The previous step is delayed for 10 seconds, and the following operation is performed:

[0110] Air system: The air compressor is turned off, and the bypass valve opening is 0. The intake valve opening is 0, and the exhaust valve opening is 0.

[0111] Hydrogen system: The opening of the hydrogen inlet valve is 0, the proportional valve is completely closed, and the hydrogen discharge valve is closed.

[0112] Hydrothermal system: The water pump speed is set to 0 rpm and the three-way valve opening is 0 (large circulation state).

[0113] Electrical system: Off mode.

[0114] Wait for the reboot.

[0115] It should be noted that, in the present invention, C1, C2, C3, and C4 can be entered according to different commands or instructions.

[0116] Embodiment 3

[0117] The process of entering C1-C4 is as follows:

[0118] S1, when receiving a shutdown command (either a normal shutdown command or an emergency shutdown command), if the air compressor speed is equal to 0, only when the valve is opened or opening, it enters the C1 path.

[0119] S2, when receiving an emergency stop command and the air compressor is not equal to 0, directly enter the C2 path.

[0120] S3, when receiving a normal shutdown command. If the air compressor speed is greater than 0, and the DCDC has not yet entered the working mode and has not drawn current, it will enter the C3 mode.

[0121] S4 When receiving a normal shutdown command, if the air compressor speed is greater than 0 and the DCDC has started to draw current, it enters C4 mode.

[0122] S5 When the system is shutting down, no matter which key mode is entered, no new key commands are accepted until the current key command is executed.

[0123] The beneficial effects of the present invention are:

[0124] 1. According to the current state of the fuel cell system, the shutdown process is entered through different paths, which can reduce the shutdown time and protect the system to prevent the system from containing water for a long time, resulting in chronic attenuation of the proton exchange membrane.

[0125] 2. It can ensure that the anode side is under positive pressure, preventing air from entering the anode side, causing a counter-polarity phenomenon and causing damage to the proton membrane.

[0126] 3. Make the shutdown process smooth to avoid exceeding the maximum pressure ratio of the air compressor and abnormal vibration caused by instability during dynamic changes.

[0127] 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 fuel cell startup failure and shutdown protection system, characterized in that: include: MCU controller, FCU controller, air system, hydrogen system, hydrothermal system and electrical system; The air system, hydrogen system, and water heat system are all connected to the fuel cell stack through pipelines; The MCU controller is used to control the FCU controller; The FCU controller is used to control the on / off actions of the air system, hydrogen system, and water heating system; The electrical system is used to supply power to the MCU controller, FCU controller, air system, hydrogen system, and hydrothermal system.

2. A hydrogen fuel cell startup failure and shutdown protection system as claimed in claim 1, characterized in that: The air system includes: an air compressor, a bypass valve, an intake valve and an exhaust valve; one end of the air compressor is connected to the air pipe, and the other end is connected to one end of the intake valve and one end of the bypass valve; the other end of the intake valve is connected to one end of the fuel cell stack; the other end of the fuel cell stack is connected to one end of the exhaust valve; the other end of the exhaust valve is connected to the tail exhaust pipe; the other end of the bypass valve is connected to the tail exhaust pipe.

3. A hydrogen fuel cell startup failure and shutdown protection system as claimed in claim 1, characterized in that: The hydrogen system includes: an intake valve, a proportional valve and an exhaust and drain valve; one end of the intake valve is connected to the hydrogen pipeline, and the other end is connected to one end of the proportional valve; the other end of the proportional valve is connected to one end of the fuel cell stack; the other end of the fuel cell stack is connected to one end of the hydrogen exhaust and drain valve; the other end of the hydrogen exhaust and drain valve is connected to the tail exhaust pipe.

4. A hydrogen fuel cell startup failure and shutdown protection system as claimed in claim 1, characterized in that: The hydrothermal system includes: a water pump, a three-way valve and a heat dissipation system; one end of the water pump is connected to the heat dissipation system through a water path to form a water circulation, and the other end is connected to the fuel cell stack; the other end of the fuel cell stack is connected to the first end of the three-way valve; the second end of the three-way valve is connected to one end of the water pump; and the third end of the three-way valve is connected to the heat dissipation system.

5. A hydrogen fuel cell startup failure and shutdown protection method, applied to the system as claimed in any one of claims 1 to 4, characterized in that: The method includes four shutdown protection modes, namely: a first mode, a second mode, a third mode and a fourth mode; The first mode is the fast mode, the second mode is the emergency shutdown mode, the third mode is the air compressor shutdown mode, and the fourth mode is the purge shutdown mode; among them, in the first mode, the air system, hydrogen system, hydrothermal system, and electrical system are all in the closed state.

6. A hydrogen fuel cell startup failure and shutdown protection method as claimed in claim 5, characterized in that: The second mode is as follows: Stage 1: The air compressor speed is 0, the bypass valve opening is 100, the intake valve opening is 100, and the exhaust valve opening is 100; the hydrogen inlet valve opening is 0, the proportional valve is closed to 0, and the hydrogen and water discharge valves are opened to 100; the water pump speed is set to 0, and the three-way valve opening is 0; the electrical system is in discharge mode until the voltage drops below 36V; After the system is depressurized, it enters the second stage; The second stage: the air compressor speed is 0, the bypass valve opening is 0, the intake valve opening is 0, and the exhaust valve opening is 0; the hydrogen inlet valve opening is 0, the proportional valve is closed to 0, and the hydrogen and water discharge valves are closed to 0; the water pump speed is set to 0, and the three-way valve opening is 0; the electrical system is closed; wait for the next start.

7. A hydrogen fuel cell startup failure and shutdown protection method as claimed in claim 5, characterized in that: The third mode is as follows: Phase 1: The air compressor speed remains unchanged before the key, the bypass valve opening is 100; the intake valve opening is 100, the exhaust valve opening is 100; the hydrogen inlet valve opening is 100, the proportional valve works normally, and the hydrogen and water discharge valve is 100; the water pump speed setting remains unchanged, the three-way valve opening is 0; the electrical system works normally; The second stage: slowly reduce the bypass valve opening. When it is reduced to the preset value, the air compressor speed is 0, the hydrogen inlet valve opening is 100, the proportional valve works normally, and the hydrogen discharge and drainage valve is opened to 0; the water pump speed is set to the preset speed, and the three-way valve opening is 0; the electrical system is in discharge mode until the system voltage drops below 36V; The third stage: when the air compressor speed is 0, the bypass valve opening is 0. The intake valve opening is 0, the exhaust valve opening is 0; the hydrogen inlet valve opening is 0, the proportional valve is closed, and the hydrogen and water discharge valves are opened to 0; the water pump speed is set to 0, the three-way valve opening is 0; the electrical system is closed; wait for the next start.

8. A hydrogen fuel cell startup failure and shutdown protection method as claimed in claim 5, characterized in that: The fourth mode is specifically: Phase 1: The air compressor speed is changed to the first preset ratio of the maximum speed, and the bypass valve opening is 0; the intake valve opening is 100, and the exhaust valve opening is 100; the hydrogen inlet valve opening is 100, the proportional valve works normally, and the hydrogen and water discharge valves are opened to 100; the water pump speed is set to the first preset ratio of the maximum speed, and the three-way valve opening is 0; the electrical system is in DC-DC working mode to ensure that it does not exceed the allowable working voltage of the fuel cell stack; Stage 2: After the preset time, the bypass valve is opened to 100, and the air compressor speed is reduced to the second preset ratio of the maximum speed; the intake valve opening is 100, the exhaust valve opening is 100; the hydrogen inlet valve opening is 100, the proportional valve works normally, and the hydrogen and water discharge valves are opened to 100; the water pump speed is set to the rated speed, and the three-way valve opening is 0; the electrical system is in DC-DC working mode to ensure that it does not exceed the allowed working voltage of the fuel cell stack; Stage 3: After the preset time, the bypass valve is opened to 100, and the air compressor speed is reduced to the minimum speed of operation; the intake valve opening is 0, the exhaust valve opening is 0; the hydrogen inlet valve opening is 100, and the proportional valve works normally; the hydrogen and water discharge valve is opened to 100; the water pump speed is set to the minimum allowable speed, and the three-way valve opening is 0; the electrical system is in discharge mode until the system voltage drops below 36V; Stage 4: The air compressor is at the lowest speed, the bypass valve opening is 100; the intake valve opening is 0, the exhaust valve opening is 0; the hydrogen inlet valve opening is 100, and the proportional valve works normally; The hydrogen and water discharge valve is closed; the water pump speed is set to 0 rpm, and the three-way valve opening is 0; The electrical system is shut down; Stage 5: After the preset time, the air compressor is shut down and the bypass valve opening is 0. The intake valve opening is 0, the exhaust valve opening is 0; the hydrogen inlet valve opening is 0, the proportional valve is completely closed, and the hydrogen and water discharge valves are closed; the water pump speed is set to 0, and the three-way valve opening is 0; the electrical system is shut down and waits for the next start.

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