Hybrid power system of closed space

Abstract

The invention provides a hybrid power system of a closed space. The hybrid power system comprises a gas supply device, a power supply device and a power supply device, wherein the gas supply device is used for providing hydrogen, oxygen and nitrogen; the fuel cell stack is used for converting electric energy on the basis of hydrogen, oxygen and nitrogen conveyed by the gas supply device, and the pneumatic control system is used for controlling the fuel cell stack on the basis of oxygen conveyed by the oxygen concentration sensor. Controlling the supply quantity of hydrogen, oxygen and nitrogen of the fuel cell stack in the hydrogen-oxygen fuel cell mode and the hydrogen-air fuel cell mode; and the motor is used for converting the electric energy transmitted by the fuel cell stack into kinetic energy. According to the system, by integrating the hydrogen-oxygen fuel cell mode, the hydrogen-air fuel cell mode, the gas recycling system and the control system, intelligent switching of power modes and efficient recycling of reaction gas are achieved, and flexible switching of the two working modes of the hydrogen-oxygen fuel cell and the hydrogen-air fuel cell is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fuel cell systems, and relates to a hybrid power system in a closed space. BACKGROUND

[0002] Traditional fuel cell power systems face severe and multi-faceted challenges in the practical application of closed spaces. Although the current mainstream hydrogen-air fuel cell technology is relatively mature, it must continue to rely on external air as the source of oxidant, which is impossible in closed spaces such as deep-sea submersibles, manned spacecraft, underground isolation cabins, and the like, which are isolated from the outside air, greatly restricting the application range of such power systems. On the other hand, although pure hydrogen-oxygen fuel cell systems can eliminate the dependence on external air, their stable operation requires extremely harsh reaction conditions, complex system control, and a single operating mode, making it difficult to meet the demand for flexibility of power systems in closed space tasks.

[0003] More critically, whether adopting hydrogen-air fuel cell or hydrogen-oxygen fuel cell technology, existing technical solutions generally lack efficient and safe processing and recycling mechanisms for tail gas after electrochemical reaction. In the special application of closed spaces, this defect directly leads to two prominent problems: first, unreacted fuel and oxidant are directly discharged or simply processed, resulting in serious waste of valuable energy and significantly shortening the continuous operation time and mission endurance of the entire power system; second, especially hydrogen, its accumulation in a limited space can easily form an explosive atmosphere, posing a serious threat to equipment and personnel safety. Therefore, existing technologies inevitably have inherent defects such as limited application scenarios, low fuel comprehensive utilization rate, and insufficient system intrinsic safety.

[0004] Existing fuel cell power systems for closed spaces are mainly constructed around a single hydrogen-air fuel cell or hydrogen-oxygen fuel cell system, with a single operating mode. Whether based on a hydrogen-air fuel cell system or a hydrogen-oxygen fuel cell system, the system is fixed in its pre-set single working state and lacks the ability to switch between different working modes. This inherent mode singularity makes it difficult for the system to adapt to the complex and variable application requirements in closed spaces such as deep-sea, aerospace, etc., greatly limiting the range of its application scenarios.

[0005] In terms of gas utilization, existing technologies have low efficiency in handling unreacted hydrogen and oxygen. Most systems use direct discharge to the closed environment or processing through a tail gas catalytic device. The direct discharge method not only causes serious waste of fuel, greatly limiting the system's endurance, but also leads to the accumulation of hydrogen in the closed space, posing a significant safety hazard. The catalytic processing method can eliminate the risk of hydrogen, but it converts the unused chemical energy into heat energy, fails to achieve efficient energy utilization, and increases the complexity of additional devices and control.

[0006] At present, the disclosed technical solutions are mostly focused on the improvement of single fuel cell system, such as optimizing the method of maintaining the gas composition in the sealed cabin or improving the tail gas treatment device, and there is a lack of an integrated system design that can realize efficient recycling of reaction gas and intelligently switch between different working modes according to the needs of actual application scenarios. SUMMARY

[0007] In order to solve the technical problems of single operation mode, low fuel utilization rate, dependence on external air and poor system adaptability in existing closed space power systems, the technical solution adopted by the present application is: a hybrid power system for a closed space, comprising: a gas supply device for providing hydrogen, oxygen and nitrogen; a fuel cell stack for converting electrical energy based on the hydrogen, oxygen and nitrogen delivered by the gas supply device; an oxygen concentration sensor for monitoring the oxygen concentration at the cathode inlet of the fuel cell stack; a pneumatic control system for controlling the supply amount of hydrogen, oxygen and nitrogen of the fuel cell stack in hydrogen-oxygen fuel cell mode and hydrogen-air fuel cell mode based on the oxygen delivered by the oxygen concentration sensor; an electric motor for converting the electrical energy delivered by the fuel cell stack into kinetic energy.

[0008] Further, the gas supply device comprises: a nitrogen tank for providing nitrogen; an oxygen tank for providing hydrogen; a hydrogen supply device for providing hydrogen.

[0009] Further, it further comprises a tail gas treatment device for receiving the oxygen and oxygen generated by the fuel cell stack and providing them to the fuel cell stack again.

[0010] Further, the tail gas treatment device comprises: a hydrogen treatment device for storing the hydrogen discharged by the fuel cell stack; an oxygen treatment device for storing the oxygen discharged by the fuel cell stack; a hydrogen circulation pump for delivering the hydrogen discharged by the fuel cell stack that does not participate in the reaction to the fuel cell stack; an oxygen circulation pump for delivering the oxygen discharged by the fuel cell stack that does not participate in the reaction to the fuel cell stack; a lithium battery pack for providing initial power to the hydrogen circulation pump and the oxygen circulation pump; Pressure sensor: used for real-time monitoring of the pressure at the cathode and anode outlets of the fuel cell stack, respectively; Controller: based on the pressure at the anode and cathode outlets transmitted by the pressure sensor, the hydrogen circulation pump, oxygen circulation pump and lithium battery pack are controlled, and the recycling and reuse of hydrogen and oxygen are carried out; when the pressure sensor monitors that the pressure value exceeds the predetermined safety threshold, it means that the gas in the circulation system is excessive, and the excess hydrogen and oxygen are introduced into the hydrogen treatment device and the oxygen treatment device, respectively.

[0011] Further, the process of controlling the supply amount of hydrogen, oxygen and nitrogen of the fuel cell stack in the hydrogen-oxygen fuel cell mode and the hydrogen-air fuel cell mode is as follows: When the hydrogen-oxygen fuel cell mode is selected, the pneumatic control system closes the valve connected to the nitrogen tank, and opens the valves connected to the hydrogen supply device and the oxygen tank; At this time, hydrogen is sent to the anode of the fuel cell stack, and oxygen is sent to the cathode of the fuel cell stack. When the hydrogen-air fuel cell mode is selected, the pneumatic control system will open the valves of the nitrogen tank and the oxygen tank at the same time, and will deliver nitrogen and oxygen to the cathode of the stack according to a predetermined ratio.

[0012] Further, it also includes a stack monitoring module for real-time monitoring of the output voltage and output current of the fuel cell stack, The controller, based on the output voltage and output current transmitted by the stack monitoring module, stops the lithium battery pack when the voltage and current output of the fuel cell stack are stable.

[0013] Further, the predetermined ratio is 4:1.

[0014] The present application provides a hybrid power system for a closed space. By integrating the hydrogen-oxygen fuel cell mode, the hydrogen-air fuel cell mode, the gas recycling system and the control system, the system realizes intelligent switching of power modes and efficient recycling of reaction gases. The system realizes flexible switching between the hydrogen-oxygen fuel cell mode and the hydrogen-air fuel cell mode.

[0015] The present application can select the optimal power mode according to the specific application scenario of the closed space: hydrogen-oxygen fuel cell mode and hydrogen-air fuel cell mode. The mode can be selected manually according to the application scenario. Compared with the traditional fuel cell system mode, which is single and dependent on external air, the application significantly widens the application scenario.

[0016] The application constructs a complete tail gas treatment and recycling system. The residual hydrogen and oxygen after the fuel cell reaction are returned to the inlet for recycling reaction through the gas circulating pump, and a small amount of residual gas is treated by the hydrogen collecting device and the oxygen collecting device. The application not only solves the tail gas emission problem of the fuel cell in the closed space, but also ensures the safety of the system in the closed environment. At the same time, the reaction gas is efficiently recycled, greatly improving the fuel utilization rate and the system endurance.

[0017] The application relates to an intelligent control strategy based on real-time monitoring. The oxygen concentration sensor continuously monitors the environment in the system and feeds back to the pneumatic control system to dynamically adjust the gas supply parameters of the oxygen supply device. The design can ensure that the system can maintain stable oxygen concentration under different modes and workloads, and improves the self-adaptive ability, stability and reliability of the system.

[0018] The application has the following beneficial effects: Compared with the traditional single-mode fuel cell system, the mixed power system for the closed space proposed by the application innovatively realizes flexible switching between the hydrogen-oxygen fuel cell mode and the hydrogen-air fuel cell mode, so that the system can meet the needs of different application scenarios, and the applicability and task flexibility of the system are significantly improved.

[0019] 2. The traditional fuel cell system mainly discharges or burns the unreacted gas, which increases the complexity and space utilization of the system. In view of the space limitation and safety problem of the closed place, the application constructs a closed loop through the gas circulating pump to return the unreacted hydrogen and oxygen to the reaction process, and combines the simple tail gas collecting device to realize the recycling of a small amount of residual gas, which greatly improves the fuel utilization efficiency, system integration and safety.

[0020] 3. The hydrogen-air fuel cell in the prior art depends on external air or a complex simulation system, while the application proportionally adjusts the supply of nitrogen and oxygen to simulate the air composition independently without external air, which simplifies the system structure and enhances the independent operation ability of the system.

[0021] 4. The application adopts the real-time feedback and intelligent control strategy based on the oxygen concentration sensor to dynamically adjust the gas supply parameters, so that the system can stably and efficiently operate under different loads and modes, and the self-adaptive ability and reliability of the system are improved.

[0022] 5、The application realizes energy optimization management of the system in the starting and running stages through the cooperation of the fuel cell stack and the lithium battery pack, guarantees the rapid starting and dynamic response capability, and improves the overall energy utilization efficiency. Meanwhile, the system integrates a gas recycling mechanism, greatly reduces fuel consumption, and adopts a switchable dual-mode operation strategy, so that the system can flexibly select the most economical operation mode according to the task requirements, not only provides a stable, efficient and clean power solution for various closed spaces, but also significantly reduces the whole life cycle operation cost, and the overall economy is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 It is a structure diagram of a hybrid power system of a closed space.

[0025] The drawings show that: 1, fuel cell stack, 2, oxygen concentration sensor, 3, controller, 4, motor, 5, hydrogen supply device, 6, nitrogen tank, 7, oxygen tank, 8, lithium battery pack, 9, hydrogen circulation pump, 10, oxygen circulation pump, 11, hydrogen treatment device, 12, oxygen treatment device, 13, pneumatic control system, 14, stack monitoring module, 15, pressure sensor. DETAILED DESCRIPTION

[0026] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict, and the present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0027] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0028] A hybrid power system of a closed space comprises: Gas supply device: for providing hydrogen, oxygen and nitrogen; Fuel cell stack 1: for converting electric energy based on hydrogen, oxygen and nitrogen delivered by the gas supply device, while emitting hydrogen and oxygen; Oxygen concentration sensor 2: for monitoring the oxygen concentration at the key position of the fuel cell stack 1; Pneumatic control system 13: for controlling the supply amount of hydrogen, oxygen and nitrogen of the fuel cell stack 1 in the hydrogen-oxygen fuel cell mode and the hydrogen-air fuel cell mode according to the application scenario based on the oxygen delivered by the oxygen concentration sensor 2. Electric motor 4: for converting the electric energy delivered by the fuel cell stack 1 into kinetic energy.

[0029] The gas supply device comprises: Nitrogen tank 6: for providing nitrogen; Oxygen tank 7: for providing hydrogen; Hydrogen supply device 5: for providing hydrogen.

[0030] Further, it also comprises a tail gas treatment device for receiving the oxygen and oxygen generated by the fuel cell stack 1 and providing them to the fuel cell stack 1 again.

[0031] The tail gas treatment device comprises: Hydrogen treatment device 11: for storing the hydrogen emitted by the fuel cell stack 1; Oxygen treatment device 12: for storing the oxygen emitted by the fuel cell stack 1; Hydrogen circulating pump 9: for delivering the hydrogen not involved in the reaction emitted by the fuel cell stack 1 to the fuel cell stack 1; Oxygen circulating pump 10: for delivering the oxygen not involved in the reaction emitted by the fuel cell stack 1 to the fuel cell stack 1; Lithium battery pack 8: for providing power supply to the hydrogen circulating pump 9 and the oxygen circulating pump 10; Pressure sensor 15: for real-time monitoring of the pressure at the cathode and anode outlets of the fuel cell stack, respectively; Controller 3: for controlling the hydrogen circulating pump 9, the oxygen circulating pump 10 and the lithium battery pack 8 based on the pressure at the anode and cathode outlets delivered by the pressure sensor 15, for recycling and reusing the hydrogen and oxygen; when the pressure sensor monitors that the pressure value exceeds the predetermined safety threshold, it means that there is excess gas in the circulating system, and the excess hydrogen and oxygen are introduced into the hydrogen treatment device 11 and the oxygen treatment device 12, respectively, to ensure the safety of the system.

[0032] The process of controlling the supply amount of hydrogen, oxygen and nitrogen of the fuel cell stack 1 in the hydrogen-oxygen fuel cell mode and the hydrogen-air fuel cell mode is as follows: When the hydrogen-oxygen fuel cell mode is selected, the pneumatic control system 13 closes the valve connected to the nitrogen tank 6, and opens the valves connected to the hydrogen supply device 5 and the oxygen tank 7; At this time, hydrogen is sent to the anode of the fuel cell stack 1, and oxygen is sent to the cathode of the fuel cell stack 1; When the hydrogen-air fuel cell mode is selected, the pneumatic control system 13 opens the valves of the nitrogen tank 6 and the oxygen tank 7 at the same time, and sends nitrogen and oxygen to the cathode of the stack according to a predetermined ratio. The predetermined ratio is 4:1.

[0033] Further, it also includes a stack monitoring module 14 for real-time monitoring of fuel cell stack output voltage and output current, During the entire operation, based on the output voltage and output current transmitted by the stack monitoring module 14, when the fuel cell stack voltage and current output are stable, the controller 3 issues an instruction to stop the lithium battery pack 8 from supplying power, thereby prolonging its life and optimizing system efficiency.

[0034] When the output power of the fuel cell stack 1 is stable, the lithium battery pack 8 stops supplying power.

[0035] Example 1: In typical closed space applications such as deep-sea submersibles and manned spacecraft, the dual-mode flexible switching function of the hybrid power system is crucial. This system realizes flexible switching between the hydrogen-oxygen fuel cell mode and the hydrogen-air fuel cell mode by controlling the start and stop of the nitrogen supply device to adapt to different application scenarios.

[0036] A hybrid power system for a closed space according to the present application is shown in Figure 1 The system includes a fuel cell stack 1, an oxygen concentration sensor 2, a controller 3, a motor 4, a hydrogen supply device 5, a nitrogen tank 6, an oxygen tank 7, a lithium battery pack 8, a hydrogen circulation pump 9, an oxygen circulation pump 10, a hydrogen treatment device 11, an oxygen treatment device 12, a pneumatic control system 13, a stack monitoring module 14, and a pressure sensor 15.

[0037] The working process of the entire system is as follows: when the system starts, the lithium battery pack 8 serves as the starting energy of the system, first providing initial power for the motor 4, and at the same time supplying power for the hydrogen circulation pump 9 and the oxygen circulation pump 10.

[0038] Then, the controller 3 controls the hydrogen circulation pump 9 and the oxygen circulation pump 10 to start working, respectively establishing an initial circulating gas flow in the corresponding gas circuit. Subsequently, the pneumatic control system 13 intelligently selects the optimal power mode according to the preset program or real-time working condition instructions, and performs precise gas circuit configuration.

[0039] When the hydrogen-oxygen fuel cell mode is selected, the pneumatic control system 13 closes the valve connected to the nitrogen tank 6, and opens the valves connected to the hydrogen supply device 5 and the oxygen tank 7.

[0040] At this time, hydrogen and oxygen are respectively delivered to the anode and cathode of the fuel cell stack 1.

[0041] When the hydrogen-air fuel cell mode is selected, the pneumatic control system 13 opens the valves of the nitrogen tank 6 and the oxygen tank 7 at the same time, and delivers nitrogen and oxygen to the cathode of the stack according to a predetermined ratio. The hydrogen supply device 5 can use different forms such as high-pressure gaseous hydrogen storage or metal solid-state hydrogen storage according to specific application scenarios, with high flexibility.

[0042] After the stable supply of reaction gas, the fuel cell stack 1 starts the efficient electrochemical reaction and continuously outputs electric energy. In order to ensure that the system can run stably under different working conditions and modes, the oxygen concentration sensor 2 continuously monitors the oxygen concentration at the inlet of the cathode of the fuel cell stack in real time. The monitoring data is fed back to the pneumatic control system 13 in real time, and the pneumatic control system 13 dynamically adjusts the regulating valve at the outlet of the oxygen tank 7, ensuring the high stability and self-adaptive ability of the system during operation.

[0043] At the same time, the remaining hydrogen and oxygen in the stack that have not been completely reacted are driven by the hydrogen circulation pump 9 and the oxygen circulation pump 10 coordinated by the controller 3 to be re-delivered to the stack inlet for cyclic reaction, greatly improving the utilization rate of reaction gas.

[0044] When the gas in the circulation system is excessive, the excess hydrogen and oxygen are introduced into the hydrogen treatment device 11 and the oxygen treatment device 12 respectively. Throughout the operation process, the system implements an intelligent hybrid energy management strategy.

[0045] The controller 3 stops the lithium battery pack 8 from supplying power based on the output voltage and output current signals transmitted by the stack monitoring module 14 when it is monitored that the fuel cell stack voltage and current output are stable, thereby prolonging the life of the lithium battery pack 8 and optimizing the efficiency of the system.

[0046] The hybrid power system realizes fine management of gas supply strategy and power output through the cooperation of the pneumatic control system 13 and the controller 3. When the working mode needs to be switched due to changes in operating conditions, the system can automatically and smoothly adjust the gas supply parameters to ensure stable operation of the system.

[0047] The working process in the hydrogen-oxygen fuel cell mode is as follows: when the system adopts the hydrogen-oxygen fuel cell mode, the valves connected to the hydrogen supply device 5 and the oxygen tank 7 are opened by the pneumatic control system 13.

[0048] The hydrogen supply device 5 is connected to the anode of the fuel cell stack 1, and the oxygen tank 7 is connected to the cathode of the fuel cell stack 1. When the system is running, hydrogen from the hydrogen supply device 5 and oxygen from the oxygen tank 7 undergoes electrochemical reaction in the fuel cell stack 1 to generate electric energy to drive the motor 4. The remaining hydrogen and oxygen after the reaction are re-delivered by the hydrogen circulation pump 9 and the oxygen circulation pump 10 respectively to the inlet of the fuel cell stack 1 to participate in the reaction again to realize efficient recycling of hydrogen and oxygen. The remaining hydrogen and oxygen after recycling are introduced into the hydrogen treatment device 11 and the oxygen treatment device 12 respectively for safe treatment.

[0049] The working process in the hydrogen-air fuel cell mode is as follows: when the system adopts the hydrogen-air fuel cell mode, the valves connected to the hydrogen supply device 5, the nitrogen tank 6 and the oxygen tank 7 are opened by the pneumatic control system 13. The system mixes nitrogen and oxygen at a predetermined ratio (4:1) and delivers them to the cathode of the fuel cell stack 1. At the same time, the hydrogen supply device 5 supplies hydrogen to the anode of the stack. In the stack, hydrogen reacts with the mixture of oxygen and nitrogen formed at a predetermined ratio to generate electric energy to drive the motor 4. During the reaction, the oxygen concentration sensor 2 monitors the oxygen concentration in the system in real time and feeds back the data to the pneumatic control system 13 to dynamically adjust the oxygen supply parameters to maintain the stability of the mixture composition. The hydrogen that is not consumed after the reaction is driven by the hydrogen circulation pump 9 to return to the anode of the stack for recycling; the unreacted oxygen on the cathode side is recovered by the oxygen circulation pump 10 and mixed with nitrogen to participate in the reaction again. The excess hydrogen and oxygen are introduced into the hydrogen treatment device 11 and the oxygen treatment device 12 respectively for safe treatment.

[0050] Example 2: The system startup stage is powered by the lithium battery pack 8 to drive the hydrogen circulation pump 9 and the oxygen circulation pump 10 to establish the initial gas circulation. The pneumatic control system 13 continuously collects the monitoring signals of the oxygen concentration sensor 2. When the system needs to switch from the hydrogen-oxygen mode to the hydrogen-air mode, the pneumatic control system 13 automatically starts the nitrogen tank 6 and adjusts the outlet flow valves of the nitrogen tank 6 and the oxygen tank 7 in linkage to control the nitrogen-oxygen mixing ratio to be stable around the predetermined ratio, realizing smooth transition of the operating mode. During the operation, the oxygen concentration sensor 2 monitors the environment in the system in real time.

[0051] When it is detected that the oxygen concentration is lower than the set threshold, the pneumatic control system 13 will increase the oxygen supply rate of the oxygen tank 7; if the concentration is higher than the set threshold, the oxygen supply flow will be reduced accordingly to maintain the stability of the gas composition in the system. The hydrogen and oxygen that are not completely consumed after the reaction form a closed loop through the hydrogen circulation pump 9 and the oxygen circulation pump 10 respectively to be re-delivered to the corresponding inlet of the fuel cell stack 1 to participate in the reaction, significantly improving the economy.

[0052] The controller controls the hydrogen circulation pump 9, the oxygen circulation pump 10 and the lithium battery set based on the pressure signals of the anode and cathode outlets transmitted by the pressure sensor 15, and supplies hydrogen and oxygen; when the pressure sensor 15 monitors that the pressure value exceeds a predetermined safety threshold, which means that the gas in the circulation system is excessive, the excess hydrogen and oxygen are respectively introduced into the hydrogen treatment device and the oxygen treatment device, thereby ensuring the safety and stability of long-term operation of the system.

[0053] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A hybrid power system for a confined space, characterized in that: include: Gas supply device: used to supply hydrogen, oxygen and nitrogen; Fuel cell stack: used for converting hydrogen, oxygen and nitrogen supplied by the gas supply device into electrical energy; Oxygen concentration sensor: used to monitor the oxygen concentration at the cathode inlet of the fuel cell stack; Pneumatic control system: used to control the supply of hydrogen, oxygen and nitrogen to the fuel cell stack in hydrogen-oxygen fuel cell mode and hydrogen-air fuel cell mode based on the oxygen transmitted by the oxygen concentration sensor. Electric motor: Used to convert electrical energy into kinetic energy from the fuel cell stack.

2. The hybrid power system for a confined space according to claim 1, characterized in that: The gas supply device includes: Nitrogen cylinder: Used to supply nitrogen gas; Oxygen cylinder: used to provide hydrogen; Hydrogen supply unit: Used to supply hydrogen gas.

3. A hybrid power system for a confined space according to claim 1, characterized in that: It also includes an exhaust gas treatment device for receiving oxygen and oxygen produced by the fuel cell stack and resupplying them to the fuel cell stack.

4. A hybrid power system for a confined space according to claim 1, characterized in that: The exhaust gas treatment device includes: Hydrogen processing device: used to store the hydrogen discharged from the fuel cell stack; Oxygen processing unit: used to store the oxygen discharged from the fuel cell stack; Hydrogen circulation pump: used to transfer unreacted hydrogen gas discharged from the fuel cell stack to the fuel cell stack; Oxygen circulation pump: used to transfer unreacted oxygen discharged from the fuel cell stack to the fuel cell stack; Lithium battery pack: used to provide initial power to the hydrogen circulation pump and oxygen circulation pump; Pressure sensors: used to monitor the pressure at the cathode and anode outlets of the fuel cell stack in real time, respectively; Controller: Based on the pressure transmitted by the pressure sensor at the anode and cathode outlets, the controller controls the hydrogen circulation pump, oxygen circulation pump, and lithium battery pack to recover and recycle hydrogen and oxygen. When the pressure sensor detects that the pressure value exceeds a predetermined safety threshold, it indicates that there is an excess of gas in the circulation system. The excess hydrogen and oxygen are introduced into the hydrogen treatment device and oxygen treatment device, respectively.

5. A hybrid power system for a confined space according to claim 1, characterized in that: The process of controlling the supply of hydrogen, oxygen, and nitrogen to the fuel cell stack in hydrogen-oxygen fuel cell mode and hydrogen-air fuel cell mode is as follows: When the hydrogen-oxygen fuel cell mode is selected, the pneumatic control system closes the valve connected to the nitrogen tank while opening the valves connected to the hydrogen supply device and the oxygen tank. At this point, hydrogen is delivered to the anode of the fuel cell stack, and oxygen is delivered to the cathode of the fuel cell stack. When the hydrogen-air fuel cell mode is selected, the pneumatic control system will simultaneously open the valves of the nitrogen and oxygen tanks and deliver nitrogen and oxygen to the stack cathode in a predetermined ratio.

6. A hybrid power system for a confined space according to claim 1, characterized in that: It also includes a fuel cell stack monitoring module: used to monitor the fuel cell stack output voltage and output current in real time. Based on the output voltage and output current transmitted by the fuel cell stack monitoring module, the controller stops supplying power to the lithium battery pack when it detects that the voltage and current output of the fuel cell stack are stable.

7. A hybrid power system for a confined space according to claim 1, characterized in that: The predetermined ratio is 4:1.

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