A hydrogen supply device for a fuel cell engine

Abstract

The present invention provides a hydrogen gas supply device for a fuel cell engine, which belongs to the field of fuel cell technology and solves the problem of unstable gas supply pressure in the prior art. The device includes a main proportional valve, a bypass proportional valve and an ejector integrated into one. Among them, the main proportional valve and the ejector are connected in sequence to the hydrogen inlet of the rear stack, forming a main gas supply branch for the hydrogen supply of the stack after the engine is started. The bypass proportional valve is directly connected to the hydrogen inlet of the stack, and it is connected in parallel with the main gas supply branch to form a bypass gas supply branch for the hydrogen supply of the stack that is self-starting when the engine is switched to a high operating point. When switching to a high operating point, the main gas supply branch alone cannot meet the hydrogen consumption demand of the fuel cell engine. At this time, the bypass gas supply branch is turned on to continuously replenish hydrogen for the stack, so that the hydrogen pressure during the operation of the fuel cell engine is always kept higher than the air pressure, ensuring that the stack is always in an efficient working state.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a hydrogen gas supply device for a fuel cell engine. Background Art

[0002] Hydrogen fuel cell vehicles are a new energy vehicle with broad development prospects, with many advantages such as short hydrogen refueling time and long driving range. The fuel cell engine it carries usually includes a fuel cell stack and peripheral subsystems such as hydrogen supply, air supply, and cooling cycle. Since the membrane electrode in the fuel cell stack has very high requirements for the stability of the gas supply pressure, the pressure fluctuation of the hydrogen supply subsystem needs to be relatively stable.

[0003] The existing hydrogen supply subsystem mainly uses a switch-type hydrogen injector. In order to improve the accuracy of flow control, some professionals have proposed a control scheme using a hydrogen injector + proportional valve. In this control scheme, the FCU outputs a PWM signal to control the proportional valve to control the flow of hydrogen entering the stack output by the hydrogen injector. However, since the switching working point of a single proportional valve generally results in unstable gas supply pressure, the life of the fuel cell stack is affected. Summary of the invention

[0004] In view of the above analysis, an embodiment of the present invention aims to provide a hydrogen gas supply device for a fuel cell engine, so as to solve the problem of unstable gas supply pressure in the prior art.

[0005] On the one hand, an embodiment of the present invention provides a hydrogen supply device for a fuel cell engine, comprising a main proportional valve, a bypass proportional valve, an ejector and a controller integrated into one body; wherein:

[0006] The main proportional valve and the ejector are connected in sequence to the hydrogen inlet of the fuel cell stack, forming a main gas supply branch that automatically starts when the engine is started and automatically disconnects when the engine is shut down;

[0007] The bypass proportional valve is directly connected to the hydrogen inlet of the fuel cell stack, and is connected in parallel with the main gas supply branch to form a bypass gas supply branch that automatically starts when the engine switches from a low operating point to a high operating point after starting, and automatically disconnects when the engine switches from a high operating point to a low operating point;

[0008] The controller is used to control the main proportional valve to open and the bypass proportional valve to close when the engine is running at a low operating point; and after receiving a control command for the engine to switch to a high operating point, first increase the opening of the main proportional valve, then start the bypass proportional valve, adjust the opening of the bypass proportional valve according to the target inlet gas pressure of the high operating point, and at the same time adjust the opening of the main proportional valve according to the real-time jet gas pressure to eliminate the delayed response of the bypass proportional valve starting.

[0009] The beneficial effects of the above technical solution are as follows: the hydrogen supply device integrates an ejector and two proportional valves. By controlling the main proportional valve to open first and the bypass proportional valve to close, when the engine is running at a low operating point after starting, the opening of the main proportional valve is adjusted with the hydrogen pressure entering the stack as the control target, so that the device can provide hydrogen to the stack at a point where the fuel cell operating current is low. When the engine switches to a high operating point (the fuel cell operating current needs to be increased), the main gas supply branch working alone cannot meet the hydrogen consumption demand of the fuel cell engine. At this time, the bypass proportional valve is opened to continuously replenish hydrogen for the fuel cell stack to ensure that the stack in the fuel cell engine is always in an efficient working state.

[0010] Based on the further improvement of the above device, the hydrogen supply device also includes an explosion-proof housing; wherein,

[0011] The main proportional valve, bypass proportional valve and ejector are all integrated inside the explosion-proof housing;

[0012] The outer side of the explosion-proof shell is provided with a first hydrogen input end for connecting to a high-pressure hydrogen cylinder, a second hydrogen input end for connecting to a hydrogen tail gas outlet of a fuel cell stack, and a hydrogen output end for connecting to a hydrogen inlet of the fuel cell stack; and the first hydrogen input end is connected to a main proportional valve in the explosion-proof shell, the second hydrogen input end is connected to a drainage inlet of an ejector in the explosion-proof shell, and the hydrogen output end is connected to the hydrogen inlet of the fuel cell stack outside the explosion-proof shell.

[0013] Furthermore, the controller further comprises:

[0014] A data acquisition unit is used to obtain the jet gas pressure of the ejector, the gas pressure entering the pile, and the opening current of the bypass proportional valve, and send them to the data processing and control unit;

[0015] The data processing and control unit is used to control the main proportional valve to open and the bypass proportional valve to close when the engine is running at a low operating point, so as to provide hydrogen to the fuel cell stack only through the main gas supply branch; and after receiving a control command for the engine to switch to a high operating point, first increase the opening of the main proportional valve, and then issue a start command to the bypass proportional valve until it is monitored that the opening current of the bypass proportional valve reaches 50%~60% of the starting current, adjust the opening of the bypass proportional valve so that the real-time gas pressure entering the stack reaches a set range above the target gas pressure entering the stack at the high operating point, and at the same time adjust the opening of the main proportional valve so that the real-time jet gas pressure reaches the set opening corresponding to the high operating point, so as to eliminate the delayed response of the bypass proportional valve start-up.

[0016] Furthermore, the data acquisition unit further comprises:

[0017] The first pressure sensor is arranged at the jet inlet of the ejector or the output end of the main proportional valve to obtain the real-time jet gas pressure.P 1;

[0018] The second pressure sensor is installed on the inner wall of the pipe at the hydrogen inlet of the fuel cell stack to obtain the real-time gas pressure entering the stack. P 2;

[0019] The current sensor is arranged at the control end of the bypass proportional valve and is used to obtain the opening current of the bypass proportional valve.

[0020] Furthermore, the data processing and control unit executes the following program:

[0021] S1. When the engine is running at a low operating point, the main proportional valve is controlled to open and the bypass proportional valve is closed, so that hydrogen is supplied to the fuel cell stack only through the main gas supply branch, and the opening of the main proportional valve is controlled to maintain the hydrogen pressure entering the stack. P 2. Stability;

[0022] S2. After receiving the control command to switch the engine to the high operating point, first increase the opening of the main proportional valve to make the hydrogen pressure entering the reactor P 2 reaches the original value before switching + calibration pressure S The sum of the first and second timers is started, and a start command is sent to the bypass proportional valve at the same time;

[0023] S3. Monitor the opening current of the bypass proportional valve until the opening current reaches 50% of the starting current, and adjust the opening of the bypass proportional valve to make the real-time gas pressure P 2. Achieve the target hydrogen value for the high operating point + the rated pressure S The sum of the two, and at the same time adjust the opening of the main proportional valve so that the real-time jet gas pressure P 1 When it reaches 50kPa, start the second timer;

[0024] S4. When the first timer reaches the calibrated time of 1s, adjust the opening of the main proportional valve so that the gas pressure entering the pile is P 2. Achieve the target hydrogen value for the high operating point and maintain the opening of the bypass proportional valve unchanged;

[0025] S5. When the second timer reaches the calibration time of 3s, according to the jet gas pressure P 1Control the opening of the main proportional valve and adjust the pressure of the gas entering the reactor P 2. Control the opening of the bypass proportional valve to maintain the hydrogen pressure entering the reactor. P 2 stability.

[0026] Furthermore, the data processing and control unit has a display module; wherein,

[0027] The display screen of the display module displays real-time data collected by the first pressure sensor, the second pressure sensor, and the current sensor.

[0028] Furthermore, the hydrogen supply device also includes a third proportional valve; wherein,

[0029] The input end of the third proportional valve is connected to the hydrogen tail gas outlet of the fuel cell stack, the output end is connected to the drainage inlet of the ejector, and the control end is connected to the output end of the controller;

[0030] The third proportional valve is integrated with the main proportional valve, the bypass proportional valve and the ejector.

[0031] Furthermore, the hydrogen supply device also includes a stop valve; wherein,

[0032] The output end of the stop valve is respectively connected to the input ends of the main proportional valve and the bypass proportional valve, and is integrated with the main proportional valve, the bypass proportional valve and the ejector.

[0033] Furthermore, the hydrogen supply device also includes a gas-liquid separator; wherein,

[0034] The input end of the gas-liquid separator is connected to the hydrogen tail gas outlet of the fuel cell stack, the gas output end is connected to the drainage inlet of the ejector via a third proportional valve, and the liquid output end is connected to the tail exhaust pipe of the fuel cell engine;

[0035] The gas-liquid separator is integrated with the third proportional valve, the main proportional valve, the bypass proportional valve and the ejector.

[0036] Furthermore, the inner walls of all pipelines in contact with hydrogen in the main gas supply branch and the bypass gas supply branch are coated with a hydrogen permeation-resistant coating.

[0037] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0038] 1. The high and low operating points of the fuel cell engine are efficiently controlled through two proportional valves.

[0039] 2. When the engine switches to a high operating point, first increase the opening of the main proportional valve to increase the hydrogen flow into the reactor, and then open the bypass proportional valve to reach the target position to overcome the response delay problem of the bypass proportional valve.

[0040] 3. Real-time monitoring of the hydrogen intake status of the fuel cell engine is performed through various pressure sensors and current sensors.

[0041] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the disclosure, nor is it intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present disclosure.

[0043] Figure 1 A schematic diagram of the composition of the hydrogen supply device of Example 1 is shown;

[0044] Figure 2 The schematic diagram of the hydrogen supply device in Example 1 is shown;

[0045] Figure 3 The hysteresis effect of the bypass proportional valve of Example 1 when it is started is shown;

[0046] Figure 4 A schematic diagram showing the effect of directly starting the bypass proportional valve on the flow rate when the operating point is switched in Example 1;

[0047] Figure 5 A schematic diagram showing the effect of the control scheme of this embodiment on the flow rate when the operating point of embodiment 1 is switched;

[0048] Figure 6 A schematic diagram of the composition of the hydrogen supply device of Example 2 is shown;

[0049] Figure 7 A schematic diagram of the control principle of the hydrogen supply device of Example 2 is shown.

[0050] Reference numerals:

[0051] 1- Main proportional valve; 2- Bypass proportional valve; 3- Ejector; 4- First pressure sensor; 5- Second pressure sensor; FCU- Controller; Bypass proportional valve- Bypass proportional valve. DETAILED DESCRIPTION

[0052] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0053] As used herein, the term "including" and its variations mean open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "based at least in part on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0054] Example 1

[0055] One embodiment of the present invention discloses a hydrogen supply device for a fuel cell engine, such as Figure 1~2 As shown, it includes a main proportional valve, a bypass proportional valve (Bypass proportional valve), an ejector and a controller which are integrated into one body.

[0056] The main proportional valve and the ejector are connected in sequence to the hydrogen inlet of the fuel cell stack, forming a main air supply branch that automatically starts when the engine starts and automatically disconnects when the engine shuts down. When the engine is at a low operating point or a high operating point, the main air supply branch is open.

[0057] The bypass proportional valve is directly connected to the hydrogen inlet of the fuel cell stack and is connected in parallel with the main gas supply branch, forming a bypass gas supply branch that automatically starts when the engine switches from a low operating point to a high operating point after starting, and automatically disconnects when the engine switches from a high operating point to a low operating point.

[0058] The controller is used to control the main proportional valve to open and the bypass proportional valve to close when the engine is running at a low operating point; and after receiving a control command for switching the engine to a high operating point, first increase the opening of the main proportional valve, then start the bypass proportional valve, adjust the opening of the bypass proportional valve according to the target stack inlet gas pressure at the high operating point, and at the same time adjust the opening of the main proportional valve according to the real-time jet gas pressure to eliminate the delayed response of the bypass proportional valve starting; and after receiving a control command for switching the engine to a low operating point, control the bypass proportional valve to close.

[0059] The above operating point can be one of the output current, output power, and required hydrogen pressure of the fuel cell stack. Taking the output current of the fuel cell stack as an example, the high operating point is when the current reaches 280 A or more, and the low operating point is when the current is less than 260 A. The current between 260 A and 280 A is the hysteresis range. When the current exceeds 280 A, the Bypass proportional valve opens, and when the current is less than 260 A, the Bypass proportional valve closes to prevent the Bypass proportional valve from frequently changing its state.

[0060] Due to its own structure, the proportional valve will not open until the control end reaches the set current value. Figure 3As shown, after reaching the set current value, the electromagnetic force generated needs to overcome the friction of the proportional valve itself and the compression force of the spring before its opening reaches the target position. This process usually causes a response delay of tens to tens of milliseconds. Considering that the proportional valve requires a certain starting current and response time to open, there is a certain hysteresis in the bypass proportional valve air supply when switching. Therefore, the hysteresis of the bypass proportional valve can be overcome by further using the above control method of the controller.

[0061] In order to illustrate the technical effect of the above control scheme, a set of comparative tests are carried out below.

[0062] Figure 4 This is a schematic diagram of the test results of directly opening the bypass proportional valve of the bypass air supply branch when switching the operating point. It can be seen that the total flow rate in and out of the stack will undergo a large mutation.

[0063] Figure 5 When switching the operating point, first increase the opening of the main proportional valve, then start the bypass proportional valve, adjust the opening of the bypass proportional valve according to the target inlet gas pressure of the high operating point, and adjust the opening of the main proportional valve according to the real-time jet gas pressure to eliminate the delayed response scheme of the bypass proportional valve start-up. It can be seen from the schematic diagram of the test results that the total flow changes slowly, the bypass slowly intervenes, and the hysteresis phenomenon is effectively suppressed.

[0064] During implementation, the engine is at a low operating point and only the main gas supply branch is turned on to provide hydrogen to the fuel cell stack. When switched to a high operating point, both the main gas supply branch and the bypass gas supply branch are turned on to supplement hydrogen to the fuel cell engine.

[0065] Compared with the prior art, the cooling device provided in this embodiment integrates an ejector and two proportional valves. By controlling the main proportional valve to open first and the bypass proportional valve to close, when the engine is running at a low operating point after starting, the opening of the main proportional valve is adjusted with the hydrogen pressure entering the stack as the control target, so that the device provides hydrogen to the stack at a point where the fuel cell operating current is low. When the engine switches to a high operating point (the fuel cell operating current needs to be increased), the main gas supply branch working alone cannot meet the hydrogen consumption demand of the fuel cell engine. At this time, the bypass proportional valve is opened to continuously replenish hydrogen for the fuel cell stack to ensure that the stack in the fuel cell engine is always in an efficient working state.

[0066] Example 2

[0067] Based on the improvement of Example 1, the hydrogen supply device further comprises an explosion-proof housing, wherein the controller, the main proportional valve, the bypass proportional valve and the ejector are all integrated inside the explosion-proof housing.

[0068] The outside of the explosion-proof shell is provided with a first hydrogen input end for connecting to a high-pressure hydrogen cylinder, a second hydrogen input end for connecting to a hydrogen tail gas outlet of a fuel cell stack, and a hydrogen output end for connecting to a hydrogen inlet of the fuel cell stack; and the first hydrogen input end is connected to a main proportional valve in the explosion-proof shell, the second hydrogen input end is connected to a drainage inlet of an ejector in the explosion-proof shell, and the hydrogen output end is connected to the hydrogen inlet of the fuel cell stack outside the explosion-proof shell.

[0069] Preferably, the controller comprises a data acquisition unit and a data processing and control unit which are connected in sequence. The output end of the controller is respectively connected to the control end of the main proportional valve and the bypass proportional valve.

[0070] The data acquisition unit is used to obtain the jet gas pressure of the ejector, the gas pressure entering the pile, and the opening current of the bypass proportional valve, and send them to the data processing and control unit.

[0071] The data processing and control unit is used to control the main proportional valve to open and the bypass proportional valve to close when the engine is running at a low operating point, so as to provide hydrogen to the fuel cell stack only through the main gas supply branch; and after receiving a control command for the engine to switch to a high operating point, first increase the opening of the main proportional valve, and then issue a start command to the bypass proportional valve until it is monitored that the opening current of the bypass proportional valve reaches 50%~60% of the starting current, adjust the opening of the bypass proportional valve so that the real-time gas pressure entering the stack reaches a set range above the target gas pressure entering the stack at the high operating point, and at the same time adjust the opening of the main proportional valve so that the real-time jet gas pressure reaches the set opening corresponding to the high operating point, so as to eliminate the delayed response of the bypass proportional valve start-up.

[0072] The data acquisition unit further includes a first pressure sensor, a second pressure sensor, a current sensor and a temperature sensor.

[0073] The first pressure sensor is arranged at the jet inlet of the ejector or the output end of the main proportional valve to obtain the real-time jet gas pressure. P 1. Such as Figure 6 shown.

[0074] The second pressure sensor is installed on the inner wall of the pipe at the hydrogen inlet of the fuel cell stack to obtain the real-time gas pressure entering the stack. P 2. For example Figure 6 shown.

[0075] The current sensor is arranged at the control end of the bypass proportional valve and is used to obtain the opening current of the bypass proportional valve.

[0076] The temperature sensor is installed on the inner wall of the pipe at the hydrogen inlet of the fuel cell stack and is used to obtain the temperature of the hydrogen entering the stack.

[0077] Preferably, the data processing and control unit executes the following program:

[0078] S1. When the engine is running at a low operating point, the main proportional valve is controlled to open and the bypass proportional valve is closed, so that hydrogen is supplied to the fuel cell stack only through the main gas supply branch, and the opening of the main proportional valve is controlled to maintain the hydrogen pressure entering the stack. P 2. Stability;

[0079] S2. After receiving the control command to switch the engine to the high operating point, first increase the opening of the main proportional valve to make the hydrogen pressure entering the reactor P 2 reaches the original value before switching + calibration pressure S The sum of the two starts the first timer (the timing time is set to the calibration time). B ), and at the same time send a start command to the bypass proportional valve;

[0080] S3. Monitor the opening current of the bypass proportional valve until the opening current reaches 50% of the starting current (calibrated value A ), adjust the opening of the main proportional valve so that the real-time jet gas pressure P 1 reaches 50kPa (calibrated value C ), and adjust the opening of the bypass proportional valve to make the real-time gas pressure P 2. Achieve the target hydrogen value for the high operating point + the rated pressure S The second timer starts timing (the timing time is set to the calibration time). D );

[0081] S4. When the first timer reaches the calibration time B (1s), adjust the opening of the main proportional valve so that the gas pressure entering the reactor is P 2 Reach the calibration value of the high operating point C , and maintain the opening of the bypass proportional valve unchanged;

[0082] S5. When the second timer reaches the set time D (3s), according to the jet gas pressure P 1Control the opening of the main proportional valve and adjust the pressure of the gas entering the reactor P 2. Control the opening of the bypass proportional valve to maintain the hydrogen pressure entering the reactor. P 2 stability.

[0083] For example, S is 5 kPa, B is 1 s, C is 50 kPA, D is 3 s. A , B , C , D. S It is related to the characteristics of the proportional valve and has nothing to do with the operating point of the fuel cell engine.

[0084] Control program principle see Figure 7 , when running to the switching working point, temporarily increase P 2Pressure is original value + calibration pressure S , the maintenance time is the calibration amount B At the same time, open the Bypass proportional valve. When the Bypass proportional valve duty ratio reaches the calibrated value A When the main proportional valve is switched to P 1 pressure is the control target, providing hydrogen and acting as an ejector. At this time, temporarily increase P 1Pressure is the nominal value C , maintain calibration time D .

[0085] Calibration time B After the end, P 2. The pressure is restored to the target hydrogen value. After the calibration time D is over, P 1. The pressure returns to the target value. The fuel cell engine operates normally, and the main proportional valve P 1Pressure is the control target, the Bypass proportional valve is P 2 pressure provides hydrogen for the control target.

[0086] Preferably, the data processing and control unit has a display module, wherein the display screen of the display module displays real-time data collected by the first pressure sensor, the second pressure sensor, the current sensor, and the temperature sensor.

[0087] Preferably, the hydrogen supply device further includes a third proportional valve.

[0088] The input end of the third proportional valve is connected to the hydrogen tail gas outlet of the fuel cell stack, the output end is connected to the drainage inlet of the ejector, and the control end is connected to the output end of the controller, so as to control the drainage gas flow of the ejector. The third proportional valve is integrated with the main proportional valve, the bypass proportional valve and the ejector.

[0089] Preferably, the hydrogen supply device further comprises a stop valve.

[0090] Among them, the output end of the shut-off valve is respectively connected to the input end of the main proportional valve and the bypass proportional valve, and is integrated with the main proportional valve, the bypass proportional valve and the ejector. The control end is connected to the output end of the controller, and is used to open after the fuel cell engine is started and disconnect after the fuel cell engine is shut down to ensure the safety of hydrogen use.

[0091] Preferably, the hydrogen supply device also includes a gas-liquid separator.

[0092] Among them, the input end of the gas-liquid separator is connected to the hydrogen tail gas outlet of the fuel cell stack, the gas output end is connected to the drainage inlet of the ejector through the third proportional valve, and the liquid output end is connected to the tail exhaust pipe of the fuel cell engine, which is used to reduce the moisture in the hydrogen entering the stack.

[0093] The gas-liquid separator is integrated with the third proportional valve, the main proportional valve, the bypass proportional valve and the ejector.

[0094] Preferably, the inner walls of all pipes in contact with the gas in the main gas supply branch and the bypass gas supply branch are coated with a hydrogen permeation-resistant coating to prevent hydrogen leakage and further improve the safety of hydrogen use.

[0095] Preferably, the components of the hydrogen supply device are sealed to prevent hydrogen leakage.

[0096] Compared with the prior art, the hydrogen supply device for a fuel cell engine provided in this embodiment has the following beneficial effects:

[0097] 1. The high and low operating points of the fuel cell engine are efficiently controlled through two proportional valves.

[0098] 2. When the engine switches to a high operating point, first increase the opening of the main proportional valve to increase the hydrogen flow into the reactor, and then open the bypass proportional valve to reach the target position to overcome the response delay problem of the bypass proportional valve.

[0099] 3. Real-time monitoring of the hydrogen intake status of the fuel cell engine is performed through various pressure sensors and temperature sensors.

[0100] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terms used herein are selected to best explain the principles of the embodiments, practical applications, or improvements over the prior art, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A hydrogen supply device for a fuel cell engine, characterized in that: It includes a main proportional valve, a bypass proportional valve, an ejector and a controller which are integrated into one body; wherein, The main proportional valve and the ejector are connected in sequence to the hydrogen inlet of the fuel cell stack, forming a main gas supply branch that automatically starts when the engine is started and automatically disconnects when the engine is shut down; The bypass proportional valve is directly connected to the hydrogen inlet of the fuel cell stack, and is connected in parallel with the main gas supply branch to form a bypass gas supply branch that automatically starts when the engine switches from a low operating point to a high operating point after starting, and automatically disconnects when the engine switches from a high operating point to a low operating point; The controller is used to control the main proportional valve to open and the bypass proportional valve to close when the engine is running at a low operating point; and after receiving a control command for the engine to switch to a high operating point, first increase the opening of the main proportional valve, then start the bypass proportional valve, adjust the opening of the bypass proportional valve according to the target inlet gas pressure of the high operating point, and at the same time adjust the opening of the main proportional valve according to the real-time jet gas pressure to eliminate the delayed response of the bypass proportional valve starting.

2. The hydrogen gas supply device for a fuel cell engine according to claim 1, characterized in that: Also includes an explosion-proof housing; wherein, The main proportional valve, bypass proportional valve and ejector are all integrated inside the explosion-proof housing; The outer side of the explosion-proof shell is provided with a first hydrogen input end for connecting to a high-pressure hydrogen cylinder, a second hydrogen input end for connecting to a hydrogen tail gas outlet of a fuel cell stack, and a hydrogen output end for connecting to a hydrogen inlet of the fuel cell stack; and the first hydrogen input end is connected to a main proportional valve in the explosion-proof shell, the second hydrogen input end is connected to a drainage inlet of an ejector in the explosion-proof shell, and the hydrogen output end is connected to the hydrogen inlet of the fuel cell stack outside the explosion-proof shell.

3. The hydrogen gas supply device for a fuel cell engine according to claim 1 or 2, characterized in that: The controller further comprises: A data acquisition unit is used to obtain the jet gas pressure of the ejector, the gas pressure entering the pile, and the opening current of the bypass proportional valve, and send them to the data processing and control unit; The data processing and control unit is used to control the main proportional valve to open and the bypass proportional valve to close when the engine is running at a low operating point, so as to provide hydrogen to the fuel cell stack only through the main gas supply branch; and after receiving a control command for the engine to switch to a high operating point, first increase the opening of the main proportional valve, and then issue a start command to the bypass proportional valve until it is monitored that the opening current of the bypass proportional valve reaches 50%~60% of the starting current, adjust the opening of the bypass proportional valve so that the real-time gas pressure entering the stack reaches a set range above the target gas pressure entering the stack at the high operating point, and at the same time adjust the opening of the main proportional valve so that the real-time jet gas pressure reaches the set opening corresponding to the high operating point, so as to eliminate the delayed response of the bypass proportional valve start-up.

4. The hydrogen gas supply device for a fuel cell engine according to claim 3, characterized in that: The data acquisition unit further comprises: The first pressure sensor is arranged at the jet inlet of the ejector or the output end of the main proportional valve to obtain the real-time jet gas pressure. P 1; The second pressure sensor is installed on the inner wall of the pipe at the hydrogen inlet of the fuel cell stack to obtain the real-time gas pressure entering the stack. P 2; The current sensor is arranged at the control end of the bypass proportional valve and is used to obtain the opening current of the bypass proportional valve.

5. The hydrogen gas supply device for a fuel cell engine according to claim 4, characterized in that: The data processing and control unit executes the following procedures: S1. When the engine is running at a low operating point, the main proportional valve is controlled to open and the bypass proportional valve is closed, so that hydrogen is supplied to the fuel cell stack only through the main gas supply branch, and the opening of the main proportional valve is controlled to maintain the hydrogen pressure entering the stack. P 2. Stability; S2. After receiving the control command to switch the engine to the high operating point, first increase the opening of the main proportional valve to make the hydrogen pressure entering the reactor P 2 When the sum of the original value before switching + the calibrated pressure S is reached, the first timer is started to start timing, and a start command is sent to the bypass proportional valve at the same time; S3. Monitor the opening current of the bypass proportional valve until the opening current reaches 50% of the starting current, and adjust the opening of the bypass proportional valve to make the real-time gas pressure P 2. Achieve the target hydrogen value for the high operating point + the rated pressure S The sum of the two, and at the same time adjust the opening of the main proportional valve so that the real-time jet gas pressure P 1 When it reaches 50kPa, start the second timer; S4. When the first timer reaches the calibrated time of 1s, adjust the opening of the main proportional valve so that the gas pressure entering the pile is P 2. Achieve the target hydrogen value for the high operating point and maintain the opening of the bypass proportional valve unchanged; S5. When the second timer reaches the calibration time of 3s, according to the jet gas pressure P 1Control the opening of the main proportional valve and adjust the pressure of the gas entering the reactor P 2. Control the opening of the bypass proportional valve to maintain the hydrogen pressure entering the reactor. P 2 stability.

6. The hydrogen gas supply device for a fuel cell engine according to claim 4 or 5, characterized in that: The data processing and control unit has a display module; wherein the display screen of the display module displays real-time data collected by the first pressure sensor, the second pressure sensor, and the current sensor.

7. The hydrogen gas supply device for a fuel cell engine according to any one of claims 1, 2, 4 and 5, characterized in that: Also includes a third proportional valve; wherein, The input end of the third proportional valve is connected to the hydrogen tail gas outlet of the fuel cell stack, the output end is connected to the drainage inlet of the ejector, and the control end is connected to the output end of the controller; The third proportional valve is integrated with the main proportional valve, the bypass proportional valve and the ejector.

8. The hydrogen gas supply device for a fuel cell engine according to any one of claims 1, 2, 4 and 5, characterized in that: Also includes a stop valve; wherein, The output end of the stop valve is respectively connected to the input ends of the main proportional valve and the bypass proportional valve, and is integrated with the main proportional valve, the bypass proportional valve and the ejector.

9. The hydrogen gas supply device for a fuel cell engine according to claim 7, characterized in that: Also includes a gas-liquid separator; wherein, The input end of the gas-liquid separator is connected to the hydrogen tail gas outlet of the fuel cell stack, the gas output end is connected to the drainage inlet of the ejector via a third proportional valve, and the liquid output end is connected to the tail exhaust pipe of the fuel cell engine; The gas-liquid separator is integrated with the third proportional valve, the main proportional valve, the bypass proportional valve and the ejector.

10. The hydrogen gas supply device for a fuel cell engine according to any one of claims 1, 2, 4, 5, and 9, characterized in that: The inner walls of all pipelines in contact with hydrogen in the main gas supply branch and the bypass gas supply branch are coated with a hydrogen permeation-resistant coating.

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