Hydrogen fuel cell engine air recovery system and method

Abstract

The application discloses a hydrogen fuel cell engine air recovery system and method, comprising: a main stack, a secondary stack, a waste exhaust air transmission pipeline and a hydrogen supply pipeline; the main stack is used for outputting electric energy to charge a power battery; the waste exhaust air transmission pipeline is used for transmitting the waste exhaust air output by the main stack to a first input end of the secondary stack; a bypass is connected between a hydrogen source and a second input end of the secondary stack; the hydrogen supply pipeline is used for providing hydrogen to the main stack and the secondary stack; the secondary stack is used for taking the waste exhaust air as an oxidant and outputting electric energy generated by the electrochemical reaction of the waste exhaust air and the hydrogen to assist charging the power battery. The air recovery system provided by the application recycles and utilizes the waste exhaust air generated by the main stack and takes the waste exhaust air as the oxidant of the secondary stack to provide oxygen for the secondary stack, so that the energy recovery and reuse in the system are realized, and the equivalent energy consumption of the system operation is reduced.

Description

Technical Field

[0001] This invention relates to the field of fuel cell control technology, and in particular to an air recovery system and method for a hydrogen fuel cell engine. Background Technology

[0002] As a key auxiliary component of the engine, the air compressor is responsible for providing sufficient pressure and flow of air to the fuel cell stack. However, during operation, the air compressor generates exhaust air with a certain pressure potential energy and flow rate. This energy is usually directly discharged without being effectively utilized, resulting in energy waste. Furthermore, the output power of the fuel cell engine is limited by the energy consumption of the air compressor, leading to a reduction in system efficiency. Summary of the Invention

[0003] This invention provides an air recovery system and method for a hydrogen fuel cell engine, which uses the exhaust air generated by the main fuel cell stack as a secondary energy source to act as an oxidant for the secondary fuel cell stack. The recovered electrical energy is directly used to charge the power battery or drive the air compressor in the system, thereby realizing the recovery and reuse of energy within the system and significantly improving the net output power and system efficiency of the entire hydrogen fuel cell engine.

[0004] According to one aspect of the present invention, an air recovery system for a hydrogen fuel cell engine is provided, comprising: a main fuel cell stack, a secondary fuel cell stack, an exhaust air transmission pipe, and a hydrogen supply pipe; The main battery stack includes a first input terminal, a second input terminal, and a first output terminal. The first input terminal is used to receive air, the second input terminal is used to receive hydrogen, and the main battery stack is used to output electrical energy generated by the electrochemical reaction of the air and the hydrogen to charge the power battery. The waste air transmission pipe is connected between the main fuel cell stack and the secondary fuel cell stack, and the waste air transmission pipe is used to transmit the waste air output from the main fuel cell stack to the first input terminal of the secondary fuel cell stack; The hydrogen supply pipeline includes a main line and a bypass line; the main line is connected between the hydrogen source and the second input terminal of the main fuel cell stack, and the bypass line is connected between the hydrogen source and the second input terminal of the secondary fuel cell stack; the hydrogen supply pipeline is used to supply hydrogen to the main fuel cell stack and the secondary fuel cell stack. The secondary fuel cell stack is used to use the exhaust air as an oxidant and output electrical energy generated by the electrochemical reaction of the exhaust air and the hydrogen to assist in charging the power battery.

[0005] Optionally, it may also include a main fuel cell stack voltage conversion module and a secondary fuel cell stack voltage conversion module; The main battery stack voltage conversion module is used to convert the electrical energy output from the main battery stack into voltage and output it to the power battery. The secondary fuel cell stack voltage conversion module is used to convert the electrical energy output from the secondary fuel cell stack into voltage and output it to the power battery.

[0006] Optionally, the waste air transmission duct includes a back pressure valve; The back pressure valve is located at the exhaust air outlet of the main fuel cell stack and is used to regulate the pressure of the exhaust air.

[0007] Optionally, the waste air transmission duct further includes a first flow controller; The first flow controller is connected between the back pressure valve and the first input terminal of the secondary fuel cell stack, and the first flow controller is used to regulate the flow rate of the exhaust air.

[0008] Optionally, the waste air transmission duct further includes a first three-way valve; The first end of the first three-way valve is connected to the exhaust air outlet of the main fuel cell stack, the second end of the first three-way valve is connected to the first input end of the secondary fuel cell stack, and the third end of the first three-way valve is used to discharge the exhaust air.

[0009] Optionally, the hydrogen supply pipeline includes a second three-way valve; The first end of the second three-way valve is connected to the hydrogen source, the second end of the second three-way valve is connected to the second input end of the main fuel cell stack, and the third end of the second three-way valve is connected to the second input end of the secondary fuel cell stack.

[0010] Optionally, the hydrogen supply pipeline also includes a pressure reducing valve; The first end of the pressure reducing valve is connected to the third end of the second three-way valve, and the second end of the pressure reducing valve is connected to the second input end of the secondary fuel cell stack. The pressure reducing valve is used to reduce the hydrogen pressure input to the secondary fuel cell stack.

[0011] Optionally, the hydrogen supply pipeline further includes a second flow controller; The second flow controller is connected between the pressure reducing valve and the second input terminal of the secondary fuel cell stack, and is used to regulate the flow rate of hydrogen gas input to the secondary fuel cell stack.

[0012] Optionally, an air compressor may also be included; The air compressor is connected between the air source and the first input terminal of the main electric stack, and the air compressor is used to compress the air and transmit it to the main electric stack.

[0013] According to a second aspect of the present invention, an air recovery method for a hydrogen fuel cell engine is provided, for implementing the air recovery system of the hydrogen fuel cell engine as described in any one of the first aspects of the present invention, the air recovery method comprising: Obtain the state of charge of the power battery and the operating status of the main battery stack; When the state of charge of the power battery is greater than or equal to the first threshold, the exhaust air transmission pipe is controlled to be in the discharge state so as to discharge the exhaust air generated by the main battery stack. When the state of charge of the power battery is less than the first threshold and the operating state of the main battery stack meets the preset conditions, the waste air transmission pipeline is controlled to be in the recovery state so as to transport the waste air generated by the main battery stack to the secondary battery stack, and the hydrogen supply pipeline is controlled to supply hydrogen to the secondary battery stack so that the secondary battery stack can use the oxygen in the waste air to generate electricity.

[0014] This invention provides an air recovery system and method for a hydrogen fuel cell engine, comprising: a main fuel cell stack, a secondary fuel cell stack, an exhaust air transmission pipeline, and a hydrogen supply pipeline; the main fuel cell stack includes a first input terminal, a second input terminal, and a first output terminal, the first input terminal being used to receive air, the second input terminal being used to receive hydrogen, and the main fuel cell stack being used to output electrical energy generated by the electrochemical reaction of air and hydrogen to charge the power battery; the exhaust air transmission pipeline is connected between the main fuel cell stack and the secondary fuel cell stack, and is used to transmit the exhaust air output from the main fuel cell stack to the first input terminal of the secondary fuel cell stack; the hydrogen supply pipeline includes a main path and a bypass path; the main path is connected between the hydrogen source and the second input terminal of the main fuel cell stack, and the bypass path is connected between the hydrogen source and the second input terminal of the secondary fuel cell stack; the hydrogen supply pipeline is used to supply hydrogen to the main fuel cell stack and the secondary fuel cell stack; the secondary fuel cell stack is used to use exhaust air as an oxidant and output electrical energy generated by the electrochemical reaction of exhaust air and hydrogen to assist in charging the power battery. The air recovery system for a hydrogen fuel cell engine provided by this invention uses the exhaust air generated by the main fuel cell stack as a secondary energy source, which is used as an oxidant for the secondary fuel cell stack. The recovered electrical energy is directly used to charge the power battery or drive the air compressor in the system, thereby realizing the recovery and reuse of energy within the system and significantly improving the net output power and system efficiency of the entire hydrogen fuel cell engine.

[0015] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1This is a schematic diagram of the structure of an air recovery system for a hydrogen fuel cell engine provided in an embodiment of the present invention; Figure 2 This is a flowchart of an air recovery method for a hydrogen fuel cell engine provided in an embodiment of the present invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0020] Figure 1 This is a schematic diagram of the structure of an air recovery system for a hydrogen fuel cell engine provided in an embodiment of the present invention. (Refer to...) Figure 1 The air recovery system for a hydrogen fuel cell engine provided in this embodiment of the invention includes: a main fuel cell stack 1, a secondary fuel cell stack 2, an exhaust air transmission pipe 100, and a hydrogen supply pipe 200. The main fuel cell stack 1 includes a first input terminal, a second input terminal, and a first output terminal. The first input terminal is used to receive air, and the second input terminal is used to receive hydrogen. The main fuel cell stack 1 is used to output electrical energy generated by the electrochemical reaction of air and hydrogen to charge the power battery 3. The exhaust air transmission pipe 100 connects the main fuel cell stack 1 and the secondary fuel cell stack 2, and the exhaust air... The transmission pipeline 100 is used to transmit the exhaust air output from the main fuel cell stack 1 to the first input terminal of the secondary fuel cell stack 2; the hydrogen supply pipeline 200 includes a main path and a bypass path; the main path is connected between the hydrogen source and the second input terminal of the main fuel cell stack 1, and the bypass path is connected between the hydrogen source and the second input terminal of the secondary fuel cell stack 2; the hydrogen supply pipeline 200 is used to supply hydrogen to the main fuel cell stack 1 and the secondary fuel cell stack 2; the secondary fuel cell stack 2 is used to use exhaust air as an oxidant and output electrical energy generated by the electrochemical reaction of exhaust air and hydrogen to assist in charging the power battery 3.

[0021] Specifically, this invention provides an air recovery system for a hydrogen fuel cell engine, including a main fuel cell stack 1, a secondary fuel cell stack 2, an exhaust air transmission pipe 100, and a hydrogen supply pipe 200. The main fuel cell stack 1 includes a first input terminal, a second input terminal, and a first output terminal. The first input terminal receives air, and the second input terminal receives hydrogen. The main fuel cell stack 1 utilizes the input air and hydrogen to undergo an electrochemical reaction, converting the chemical energy of hydrogen and oxygen (the oxygen source here is oxygen from the air) into electrical energy. The generated electrical energy is then output through the first output terminal to provide power to the power battery 3.

[0022] During the operation of the main fuel cell stack 1, the oxygen in the air input to the main fuel cell stack 1 cannot be completely consumed. Therefore, the exhaust air generated after the main fuel cell stack 1 completes the electrochemical reaction still contains a certain amount of oxygen and a large amount of water vapor. The exhaust air transmission pipe 100 transports the exhaust air output from the main fuel cell stack 1 to the secondary fuel cell stack 2, so that the exhaust air generated by the main fuel cell stack 1 can be further utilized. The exhaust air transmission pipe 100 is connected between the main fuel cell stack 1 and the secondary fuel cell stack 2. One end of the exhaust air transmission pipe 100 is connected to the exhaust air output terminal of the main fuel cell stack 1, and the other end is connected to the first input terminal of the secondary fuel cell stack 2, for inputting the exhaust air generated by the main fuel cell stack 1 to the secondary fuel cell stack 2. The exhaust air (including unreacted oxygen) serves as the oxidant source required for the electrochemical reaction in the secondary fuel cell stack 2.

[0023] A hydrogen supply pipeline 200 is used to supply hydrogen to both the main fuel cell stack 1 and the secondary fuel cell stack 2. The hydrogen supply pipeline 200 includes a main line and a bypass line. The main line connects the hydrogen source to the second input terminal of the main fuel cell stack 1, supplying hydrogen to the main fuel cell stack 1. The bypass line connects the hydrogen source to the second input terminal of the secondary fuel cell stack 2, supplementing the secondary fuel cell stack 2 with hydrogen. By providing an independent hydrogen supply bypass 200, the secondary fuel cell stack 2 can obtain enough hydrogen to meet the electrochemical reaction requirements while receiving exhaust air from the main fuel cell stack 1, thus ensuring the continuous operation of the secondary fuel cell stack 2.

[0024] Secondary fuel cell stack 2 receives exhaust air and hydrogen, and utilizes the remaining oxygen in the exhaust air to undergo an electrochemical reaction with the hydrogen, further converting the unused oxidation capacity of the remaining oxygen into electrical energy. The electrical energy output from secondary fuel cell stack 2 is used to assist in charging the power battery 3, thereby realizing the recovery and utilization of the remaining energy in the exhaust air of the main fuel cell stack 1. Furthermore, the main fuel cell stack 1 serves as the main power generation unit of the fuel cell engine, providing the main output power; secondary fuel cell stack 2 serves as an exhaust air energy recovery unit, used to reuse the remaining oxygen in the exhaust air output from the main fuel cell stack 1. Therefore, the power rating of secondary fuel cell stack 2 is lower than that of main fuel cell stack 1.

[0025] The air recovery system for a hydrogen fuel cell engine provided by this invention uses the exhaust air generated by the main fuel cell stack as a secondary energy source, which is used as an oxidant for the secondary fuel cell stack. The recovered electrical energy is directly used to charge the power battery or drive the air compressor in the system, thereby realizing the recovery and reuse of energy within the system and significantly improving the net output power and system efficiency of the entire hydrogen fuel cell engine.

[0026] Optional, continue to refer to Figure 1 The air recovery system for the hydrogen fuel cell engine provided by the present invention further includes a main stack voltage conversion module 4 and a secondary stack voltage conversion module 5; the main stack voltage conversion module 4 is used to convert the voltage of the electrical energy output by the main stack 1 and output it to the power battery 3; the secondary stack voltage conversion module 5 is used to convert the voltage of the electrical energy output by the secondary stack 2 and output it to the power battery 3.

[0027] Specifically, the main battery stack voltage conversion module 4 is connected between the main battery stack 1 and the power battery 3. It is used to receive the electrical energy output by the main battery stack 1 and convert the electrical energy into voltage so that the voltage output by the main battery stack 1 matches the charging voltage of the power battery 3. Then, the converted electrical energy is output to the power battery 3 to charge the power battery 3.

[0028] The secondary fuel cell stack voltage conversion module 5 is connected between the secondary fuel cell stack 2 and the power battery 3. It is used to receive the electrical energy output by the secondary fuel cell stack 2 and convert the electrical energy into voltage so that the voltage output by the secondary fuel cell stack 2 meets the charging requirements of the power battery 3. Then, the converted electrical energy is output to the power battery 3 to realize auxiliary charging of the power battery 3.

[0029] By setting the main stack voltage conversion module 4 and the secondary stack voltage conversion module 5 respectively, the main stack 1 and the secondary stack 2 can perform independent power conversion and output, avoiding the energy transmission mismatch problem caused by the difference in output voltage between the main stack 1 and the secondary stack 2, and improving the stability of the power output of the fuel cell engine.

[0030] The working principle is: when the fuel cell engine starts, the fuel cell controller ( Figure 1 (Not shown) The main battery stack voltage conversion module 4 outputs an enable command, first closing the output main precharge contactor K1 and the output main negative contactor K3. After precharging is completed, the main precharge contactor K1 is opened and the output main positive contactor K2 is closed to enable the output terminal, so that the output side of the main battery stack voltage conversion module 4 matches the voltage of the power battery 3. Then, the input main positive contactor K4 is closed to establish a connection between the main battery stack 1 and the power battery 3. When energy recovery is required during the operation of the fuel cell engine, the same principle applies as above: the output secondary positive pre-charge contactor K5 and the output secondary negative contactor K7 are closed for output pre-charge. After the pre-charge is completed, K5 is opened and the output secondary positive contactors K6 and K8 are closed, and the secondary stack 2 starts to work. The recovered energy is preferentially used for system components such as the power battery 3, so that the excess energy will be added to the power battery 3 for storage.

[0031] Optional, continue to refer to Figure 1 The exhaust air transmission pipe 100 in the air recovery system of the hydrogen fuel cell engine provided by the present invention includes a back pressure valve 101; the back pressure valve 101 is disposed at the exhaust air outlet of the main fuel cell stack 1 and is used to regulate the pressure of the exhaust air.

[0032] Specifically, during the operation of the main fuel cell stack 1, air undergoes internal reactions to form exhaust air, which is then output through the exhaust air transmission pipe 100. When the exhaust air pressure is low, it may lead to insufficient oxygen supply to the secondary fuel cell stack 2, affecting the electrochemical reaction efficiency of the secondary fuel cell stack 2; conversely, when the exhaust air pressure is too high, it may increase the air discharge resistance of the main fuel cell stack 1, affecting its normal operation. Therefore, by installing a back pressure valve 101 in the exhaust air transmission pipe 100, the flow resistance of the exhaust air can be adjusted, ensuring that the pressure states between the main fuel cell stack 1 and the secondary fuel cell stack 2 are matched.

[0033] Optional, continue to refer to Figure 1 The exhaust air transmission pipe 100 in the air recovery system of the hydrogen fuel cell engine provided by the present invention further includes a first flow controller 102; the first flow controller 102 is connected between the back pressure valve 101 and the first input terminal of the secondary stack 2, and the first flow controller 102 is used to adjust the flow rate of the exhaust air.

[0034] Specifically, the exhaust air output from the main fuel cell stack 1 is fed into the secondary fuel cell stack 2 via the exhaust air transmission pipe 100, passing through the back pressure valve 101 and the first flow controller 102 in sequence. The first flow controller 102 can adjust the exhaust air flow rate input to the secondary fuel cell stack 2 according to the operating requirements of the secondary fuel cell stack 2, so that the oxygen supply in the exhaust air input to the secondary fuel cell stack 2 matches the required oxidation dose of the secondary fuel cell stack 2.

[0035] When the secondary fuel cell stack 2 requires a large power generation capacity, the first flow controller 102 can increase the exhaust air flow rate, allowing more exhaust air containing residual oxygen to enter the secondary fuel cell stack 2, thereby increasing the oxygen supply of the secondary fuel cell stack 2. When the secondary fuel cell stack 2 does not require a large power generation capacity or the system is in a low-load state, the first flow controller 102 can reduce the exhaust air flow rate to reduce gas transport energy consumption.

[0036] Optional, continue to refer to Figure 1The exhaust air transmission pipe 100 in the air recovery system of the hydrogen fuel cell engine provided by the present invention further includes a first three-way valve 103; the first end of the first three-way valve 103 is connected to the exhaust air outlet of the main fuel cell stack 1, the second end of the first three-way valve 103 is connected to the first input end of the secondary fuel cell stack 2, and the third end of the first three-way valve 103 is used to discharge the exhaust air.

[0037] Specifically, the first three-way valve 103 is used to control the flow direction of the exhaust air output from the main fuel cell stack 1. When the system needs to recover energy from the exhaust air, the first three-way valve 103 switches to the recovery state, so that the exhaust air output from the main fuel cell stack 1 is input to the first input terminal of the secondary fuel cell stack 2 through the exhaust air transmission pipe 100, so that the secondary fuel cell stack 2 can use the remaining oxygen in the exhaust air to carry out an electrochemical reaction.

[0038] When the system does not require waste air energy recovery, the first three-way valve 103 switches to the discharge state, so that the waste air output by the main fuel cell stack 1 is discharged to the outside through the third end, thereby preventing the waste air from entering the secondary fuel cell stack 2 and affecting the system operation.

[0039] Optional, continue to refer to Figure 1 The hydrogen supply pipeline 200 in the air recovery system of the hydrogen fuel cell engine provided by the present invention includes a second three-way valve 201; the first end of the second three-way valve 201 is connected to a hydrogen source, the second end of the second three-way valve 201 is connected to the second input end of the main fuel cell stack 1, and the third end of the second three-way valve 201 is connected to the second input end of the secondary fuel cell stack 2.

[0040] Specifically, the second three-way valve 201 is used to divert the hydrogen output from the hydrogen source to selectively supply hydrogen to the main stack 1 and / or the secondary stack 2 according to the operating status of the fuel cell engine.

[0041] When the fuel cell engine generates electricity solely from the main stack 1, the second three-way valve 201 can control the connection between the hydrogen source and the main stack 1, allowing hydrogen to be input into the main stack 1 to meet the electrochemical reaction requirements of the main stack 1.

[0042] When the fuel cell engine activates the exhaust air energy recovery function, the second three-way valve 201 controls the connection between the hydrogen source and the secondary fuel cell stack 2, allowing some hydrogen to be input into the secondary fuel cell stack 2. At this time, the secondary fuel cell stack 2 simultaneously receives the exhaust air output from the main fuel cell stack 1 and the hydrogen input from the hydrogen supply pipeline 200, and utilizes the remaining oxygen in the exhaust air to undergo an electrochemical reaction with the hydrogen to generate auxiliary electrical energy.

[0043] Optional, continue to refer to Figure 1The hydrogen supply pipeline 200 in the air recovery system of the hydrogen fuel cell engine provided by the present invention also includes a pressure reducing valve 202; the first end of the pressure reducing valve 202 is connected to the third end of the second three-way valve 201, and the second end of the pressure reducing valve 202 is connected to the second input end of the secondary fuel cell stack 2. The pressure reducing valve 202 is used to reduce the hydrogen pressure input to the secondary fuel cell stack 2.

[0044] Specifically, the hydrogen output from the hydrogen source typically has a high pressure. If it is directly input into the secondary fuel cell stack 2, it may cause excessively high pressure on the anode side of the secondary fuel cell stack 2, affecting the stability of gas transmission inside the fuel cell. Therefore, by setting a pressure reducing valve 202 between the second three-way valve 201 and the secondary fuel cell stack 2, the pressure of the hydrogen input into the secondary fuel cell stack 2 can be regulated, allowing the hydrogen to enter the secondary fuel cell stack 2 at a suitable pressure and undergo an electrochemical reaction with oxygen in the exhaust air.

[0045] Optional, continue to refer to Figure 1 The hydrogen supply pipeline 200 in the air recovery system of the hydrogen fuel cell engine provided by the present invention further includes a second flow controller 203; the second flow controller 203 is connected between the pressure reducing valve 202 and the second input terminal of the secondary fuel cell stack 2, and the second flow controller 203 is used to regulate the flow rate of hydrogen input to the secondary fuel cell stack 2.

[0046] Specifically, the hydrogen gas output from the hydrogen source is diverted by the second three-way valve 201 and then enters the pressure reducing valve 202 for pressure regulation. After pressure reduction, the hydrogen gas further passes through the second flow controller 203 and is then regulated by the second flow controller 203 before being input to the secondary fuel cell stack 2.

[0047] During the operation of the secondary fuel cell stack 2, the oxygen content in the exhaust air from the main fuel cell stack 1 varies with the operating status of the main fuel cell stack 1. Therefore, the amount of hydrogen input to the secondary fuel cell stack 2 needs to match the oxygen supply in the exhaust air. By setting a second flow controller 203, the hydrogen input flow rate can be adjusted according to the operating requirements of the secondary fuel cell stack 2, so that the hydrogen entering the secondary fuel cell stack 2 and the oxygen in the exhaust air are maintained in an appropriate ratio, thereby ensuring the stable electrochemical reaction inside the secondary fuel cell stack 2.

[0048] When the secondary fuel cell stack 2 needs to increase its output power, the second flow controller 203 can increase the hydrogen supply to increase the proportion of hydrogen participating in the electrochemical reaction; when the secondary fuel cell stack 2 is in a low-power operation state or does not require energy recovery, the second flow controller 203 can reduce the hydrogen supply to reduce hydrogen consumption.

[0049] By setting a second flow controller 203, precise control of the hydrogen supply process of the secondary fuel cell stack 2 can be achieved, improving hydrogen utilization efficiency and enabling the secondary fuel cell stack 2 to stably utilize the exhaust air generated by the main fuel cell stack 1 for auxiliary power generation.

[0050] Optional, continue to refer to Figure 1 The air recovery system of the hydrogen fuel cell engine provided by the present invention also includes an air compressor 6; the air compressor 6 is connected between the air source and the first input terminal of the main fuel cell stack 1, and the air compressor 6 is used to compress the air and transmit it to the main fuel cell stack 1.

[0051] Specifically, during the operation of the main fuel cell stack 1, the air compressor 6 obtains air from the external environment and compresses the air to increase the air pressure input to the main fuel cell stack 1, so that the oxygen in the air can enter the reaction area of ​​the main fuel cell stack 1 at the flow and pressure required for the operation of the main fuel cell stack 1.

[0052] Compressed air is input into the main fuel cell stack 1 through the first input terminal and undergoes an electrochemical reaction with hydrogen supplied by the hydrogen supply pipe 200, thereby generating electrical energy. Simultaneously, since the oxygen in the air input to the main fuel cell stack 1 cannot be completely consumed, the exhaust air produced after the reaction in the main fuel cell stack 1 still contains a certain proportion of oxygen. This exhaust air is further transported to the secondary fuel cell stack 2 through the exhaust air transmission pipe 100 to achieve secondary utilization of the remaining oxygen.

[0053] By installing air compressor 6, a stable air supply can be ensured for the main fuel cell stack 1, improving the electrochemical reaction efficiency of the main fuel cell stack 1 and providing a stable oxidant source for subsequent secondary power generation using waste air.

[0054] Figure 2 This is a flowchart of an air recovery method for a hydrogen fuel cell engine provided in an embodiment of the present invention, for reference. Figure 2 Based on the same inventive concept, embodiments of the present invention provide an air recovery method for a hydrogen fuel cell engine, used to execute the air recovery system for the hydrogen fuel cell engine described in the above embodiments of the present invention. The air recovery method includes: S101. Obtain the state of charge of the power battery and the operating status of the main battery stack.

[0055] Specifically, the state of charge (SOC) of the power battery is used to characterize the remaining charge of the power battery, and the operating status of the main fuel cell stack is used to characterize whether the main fuel cell stack currently meets the conditions for waste air recovery. The operating status of the main fuel cell stack can include at least one of the following: startup status, output power status, operating temperature status, hydrogen supply status, and air supply status.

[0056] By acquiring the state of charge of the power battery and the operating status of the main stack, it is possible to determine whether the exhaust air generated by the main stack needs to be recycled and reused. Based on the determination result, the exhaust air transmission path can be controlled so that the secondary stack can use the exhaust air output by the main stack for auxiliary power generation when the operating conditions are met.

[0057] S102. When the state of charge of the power battery is greater than or equal to the first threshold, the exhaust air transmission pipe is controlled to be in the discharge state so as to discharge the exhaust air generated by the main battery stack.

[0058] Specifically, refer to Figure 1 and Figure 2 When the state of charge of the power battery 3 is high (i.e., greater than or equal to the first threshold), it indicates that the current power battery 3 has sufficient energy reserves and there is no need to further recover energy from the exhaust air generated by the main battery stack 1 through the secondary battery stack 2.

[0059] Therefore, when the state of charge of the power battery 3 is detected to be greater than or equal to the preset first threshold, the exhaust air transmission pipe 100 is controlled to switch to the discharge state, so that the exhaust air generated by the main battery stack 1 does not enter the secondary battery stack 2, but is directly discharged to the outside.

[0060] Specifically, by controlling the first three-way valve 103 to switch to the discharge position, the first end of the first three-way valve 103 is connected to the third end, and the second end of the first three-way valve 103 is closed. At this time, the exhaust air output from the main fuel cell stack 1 is discharged to the outside through the third end of the first three-way valve 103, thereby stopping the supply of exhaust air to the secondary fuel cell stack 2.

[0061] S103. When the state of charge of the power battery is less than the first threshold and the operating state of the main stack meets the preset conditions, the exhaust air transmission pipeline is controlled to be in the recovery state so as to transport the exhaust air generated by the main stack to the secondary stack, and the hydrogen supply pipeline is controlled to supply hydrogen to the secondary stack so that the secondary stack can use the oxygen in the exhaust air to generate electricity.

[0062] Specifically, when the state of charge of the power battery 3 is less than the first threshold, it indicates that the power battery 3 is currently low on charge and requires additional power.

[0063] Furthermore, the operating status of the main fuel cell stack 1 is detected. When the main fuel cell stack 1 is in an operating state that meets the conditions for waste air recovery, it indicates that the main fuel cell stack 1 can continuously output waste air containing residual oxygen. At this time, the waste air transmission pipeline 100 is controlled to switch to the recovery state.

[0064] By controlling the first three-way valve 103 to switch to the recovery position, the first end of the first three-way valve 103 is connected to the second end, and the third end is closed. At this time, the exhaust air generated by the main fuel cell stack 1 enters the exhaust air transmission pipeline 100 through the first three-way valve 103, and is further transported to the first input end of the secondary fuel cell stack 2.

[0065] Since the exhaust air discharged from the main fuel cell stack 1 still contains oxygen that has not participated in the electrochemical reaction, the secondary fuel cell stack 2 can use the exhaust air as an oxidant. Simultaneously, hydrogen is supplied to the secondary fuel cell stack 2 via the hydrogen supply pipeline 200. By controlling the second three-way valve 201, hydrogen from the hydrogen source enters the hydrogen supply branch of the secondary fuel cell stack 2, and after pressure regulation by the pressure reducing valve 202 and flow regulation by the second flow controller 203, it is input to the second input terminal of the secondary fuel cell stack 2. In the secondary fuel cell stack 2, the input hydrogen undergoes an electrochemical reaction with the oxygen in the exhaust air, converting chemical energy into electrical energy, which is output through the output terminal of the secondary fuel cell stack 2. The electrical energy output from the secondary fuel cell stack 2 is voltage-converted by the secondary fuel cell stack voltage conversion module 5 and then input to the power battery 3 to assist in charging the power battery 3.

[0066] The air recovery method for hydrogen fuel cell engines provided in this embodiment of the invention can achieve the same technical effect as the air recovery system for hydrogen fuel cell engines in any of the above embodiments of the invention, therefore, it will not be described in detail here.

[0067] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0068] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An air recovery system for a hydrogen fuel cell engine, characterized in that, include: Main fuel cell stack, secondary fuel cell stack, exhaust air transmission pipeline and hydrogen supply pipeline; The main battery stack includes a first input terminal, a second input terminal, and a first output terminal. The first input terminal is used to receive air, the second input terminal is used to receive hydrogen, and the main battery stack is used to output electrical energy generated by the electrochemical reaction of the air and the hydrogen to charge the power battery. The waste air transmission pipe is connected between the main fuel cell stack and the secondary fuel cell stack, and the waste air transmission pipe is used to transmit the waste air output from the main fuel cell stack to the first input terminal of the secondary fuel cell stack; The hydrogen supply pipeline includes a main line and a bypass line; the main line is connected between the hydrogen source and the second input terminal of the main fuel cell stack, and the bypass line is connected between the hydrogen source and the second input terminal of the secondary fuel cell stack; the hydrogen supply pipeline is used to supply hydrogen to the main fuel cell stack and the secondary fuel cell stack. The secondary fuel cell stack is used to use the exhaust air as an oxidant and output electrical energy generated by the electrochemical reaction of the exhaust air and the hydrogen to assist in charging the power battery.

2. The air recovery system for a hydrogen fuel cell engine according to claim 1, characterized in that, It also includes a main fuel cell stack voltage conversion module and a secondary fuel cell stack voltage conversion module; The main battery stack voltage conversion module is used to convert the electrical energy output from the main battery stack into voltage and output it to the power battery. The secondary fuel cell stack voltage conversion module is used to convert the electrical energy output from the secondary fuel cell stack into voltage and output it to the power battery.

3. The air recovery system for a hydrogen fuel cell engine according to claim 1, characterized in that, The waste air transmission pipeline includes a back pressure valve; The back pressure valve is located at the exhaust air outlet of the main fuel cell stack and is used to regulate the pressure of the exhaust air.

4. The air recovery system for a hydrogen fuel cell engine according to claim 3, characterized in that, The waste air transmission duct also includes a first flow controller; The first flow controller is connected between the back pressure valve and the first input terminal of the secondary fuel cell stack, and the first flow controller is used to regulate the flow rate of the exhaust air.

5. The air recovery system for a hydrogen fuel cell engine according to claim 1, characterized in that, The waste air transmission pipeline also includes a first three-way valve; The first end of the first three-way valve is connected to the exhaust air outlet of the main fuel cell stack, the second end of the first three-way valve is connected to the first input end of the secondary fuel cell stack, and the third end of the first three-way valve is used to discharge the exhaust air.

6. The air recovery system for a hydrogen fuel cell engine according to claim 1, characterized in that, The hydrogen supply pipeline includes a second three-way valve; The first end of the second three-way valve is connected to the hydrogen source, the second end of the second three-way valve is connected to the second input end of the main fuel cell stack, and the third end of the second three-way valve is connected to the second input end of the secondary fuel cell stack.

7. The air recovery system for a hydrogen fuel cell engine according to claim 6, characterized in that, The hydrogen supply pipeline also includes a pressure reducing valve; The first end of the pressure reducing valve is connected to the third end of the second three-way valve, and the second end of the pressure reducing valve is connected to the second input end of the secondary fuel cell stack. The pressure reducing valve is used to reduce the hydrogen pressure input to the secondary fuel cell stack.

8. The air recovery system for a hydrogen fuel cell engine according to claim 7, characterized in that, The hydrogen supply pipeline also includes a second flow controller; The second flow controller is connected between the pressure reducing valve and the second input terminal of the secondary fuel cell stack, and is used to regulate the flow rate of hydrogen gas input to the secondary fuel cell stack.

9. The air recovery system for a hydrogen fuel cell engine according to claim 1, characterized in that, This also includes air compressors; The air compressor is connected between the air source and the first input terminal of the main electric stack, and the air compressor is used to compress the air and transmit it to the main electric stack.

10. A method for air recovery in a hydrogen fuel cell engine, characterized in that, An air recovery system for performing any one of claims 1 to 9 of a hydrogen fuel cell engine, the air recovery method comprising: Obtain the state of charge of the power battery and the operating status of the main battery stack; When the state of charge of the power battery is greater than or equal to the first threshold, the exhaust air transmission pipe is controlled to be in the discharge state so as to discharge the exhaust air generated by the main battery stack. When the state of charge of the power battery is less than the first threshold and the operating state of the main battery stack meets the preset conditions, the waste air transmission pipeline is controlled to be in the recovery state so as to transport the waste air generated by the main battery stack to the secondary battery stack, and the hydrogen supply pipeline is controlled to supply hydrogen to the secondary battery stack so that the secondary battery stack can use the oxygen in the waste air to generate electricity.

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