A hydrogen fuel cell system and a control method thereof

Abstract

This invention relates to the technical field of fuel cells and discloses a hydrogen fuel cell system and its control method. The hydrogen fuel cell system includes a hydrogen supply subsystem, a hydrogen buffer subsystem, an SOFC fuel cell system, and a control subsystem. The hydrogen buffer subsystem includes a booster pump, a hydrogen buffer tank, and a control valve. By acquiring the power supply of the SOFC fuel cell system and the pressure changes of the hydrogen buffer tank, the pump pressure of the booster pump, the opening degree of the control valve, and the hydrogen production rate of the hydrogen supply subsystem are adjusted. This achieves dynamic adjustment of the hydrogen consumption of the hydrogen fuel cell system, avoids hydrogen waste, and reduces system operating costs.

Description

Technical Field

[0001] This invention relates to the technical field of fuel cells, and more particularly to a hydrogen fuel cell system and its control method. Background Technology

[0002] Technological advancements have led to a continuous increase in societal demand for energy. Clean energy, with its environmentally friendly and renewable characteristics, has become a key development area in the energy sector. Hydrogen energy, as a highly efficient and clean energy source, boasts advantages such as zero emissions, renewability, and high energy density, and has attracted widespread attention. Hydrogen energy can be applied in power generation, electric vehicles, and fuel cells. A hydrogen fuel cell is a power generation device that directly converts the chemical energy of hydrogen and oxygen into electrical energy.

[0003] Hydrogen fuel cell power generation systems typically include a hydrogen supply module, enabling on-demand hydrogen production and avoiding the technical challenges associated with high-pressure hydrogen storage and transportation. They are suitable for scenarios such as mobile power generation, portable applications, and distributed power generation.

[0004] The hydrogen supply module in existing hydrogen fuel cell systems can only provide a fixed flow rate of hydrogen during operation. It cannot adjust the flow rate autonomously according to the power supply and hydrogen consumption of the hydrogen fuel cell, which leads to hydrogen waste and high system operating costs. Summary of the Invention

[0005] This invention provides a hydrogen fuel cell system and its control method, which solves the technical problem of high system operating costs caused by hydrogen waste in existing hydrogen fuel cell systems.

[0006] The first aspect of the present invention provides a hydrogen fuel cell system, comprising: a hydrogen supply subsystem, a hydrogen buffer subsystem, an SOFC fuel cell system, and a control subsystem;

[0007] The hydrogen buffer subsystem includes a booster pump, a hydrogen buffer tank, and a control valve;

[0008] The hydrogen outlet of the hydrogen supply subsystem is connected to the hydrogen inlet of the booster pump, the hydrogen outlet of the booster pump is connected to the hydrogen inlet of the hydrogen buffer tank, the hydrogen outlet of the hydrogen buffer tank is connected to the hydrogen inlet of the control valve, and the hydrogen outlet of the control valve is connected to the hydrogen inlet of the SOFC fuel cell system.

[0009] The control subsystem is electrically connected to the hydrogen supply subsystem, the SOFC fuel cell system, the booster pump, the hydrogen buffer tank, and the control valve, respectively.

[0010] Optionally, the hydrogen fuel cell system further includes a waste heat recovery subsystem;

[0011] The SOFC fuel cell system includes an SOFC stack and a heat exchanger;

[0012] The hydrogen outlet of the control valve is connected to the hydrogen inlet of the SOFC stack, the exhaust gas outlet of the SOFC stack is connected to the exhaust gas inlet of the heat exchanger, the working fluid outlet of the heat exchanger is connected to the working fluid inlet of the waste heat recovery subsystem, and the working fluid outlet of the waste heat recovery subsystem is connected to the heating pipeline of the hydrogen supply subsystem.

[0013] Optionally, the waste heat recovery subsystem includes a compressor and a gas turbine;

[0014] The working fluid outlet of the SOFC gas turbine system is connected to the working fluid inlet of the compressor, the working fluid outlet of the compressor is connected to the working fluid inlet of the gas turbine, and the working fluid outlet of the gas turbine is connected to the heating pipe of the hydrogen supply subsystem.

[0015] Optionally, the waste heat recovery subsystem further includes a supercritical carbon dioxide cycle power generation module connected between the gas turbine and the hydrogen supply subsystem.

[0016] Optionally, the hydrogen supply subsystem includes a methanol-water solution storage tank, a methanol-water solution vaporizer, a methanol-water vapor reformer, and a hydrogen separator.

[0017] The methanol-water solution output end of the methanol-water solution storage tank is connected to the methanol-water solution input end of the methanol-water solution vaporizer, the methanol-water vapor output end of the methanol-water solution vaporizer is connected to the methanol-water vapor input end of the methanol-water vapor reformer, the reformed gas output end of the methanol-water vapor reformer is connected to the reformed gas input end of the hydrogen separator, and the hydrogen outlet of the hydrogen separator is connected to the hydrogen inlet of the booster pump.

[0018] Optionally, the hydrogen supply subsystem includes an ammonia storage tank, an ammonia cracking hydrogen generator, and a hydrogen separator;

[0019] The ammonia output end of the ammonia storage tank is connected to the ammonia input end of the ammonia cracking hydrogen generator, the hydrogen / nitrogen mixed gas output end of the ammonia cracking hydrogen generator is connected to the hydrogen / nitrogen mixed gas input end of the hydrogen separator, and the hydrogen outlet of the hydrogen separator is connected to the hydrogen inlet of the booster pump.

[0020] A second aspect of the present invention provides a control method for a hydrogen fuel cell system as described in any of the preceding claims, relating to a hydrogen supply subsystem, a hydrogen buffer subsystem, an SOFC fuel cell system, and a control subsystem of the hydrogen fuel cell system; the control method includes:

[0021] The control subsystem obtains the power supply of the SOFC fuel cell system and adjusts the opening of the control valve of the hydrogen buffer subsystem according to the power supply change signal.

[0022] The control subsystem obtains the pressure of the hydrogen buffer tank of the hydrogen buffer subsystem and adjusts the pump pressure of the booster pump of the hydrogen buffer subsystem and the hydrogen production rate of the hydrogen supply subsystem according to the pressure.

[0023] Optionally, the step of obtaining the power supply of the SOFC fuel cell system through the control subsystem and adjusting the opening of the control valve of the hydrogen buffer subsystem according to the power supply includes:

[0024] The control subsystem obtains the power supply of the SOFC fuel cell system at a preset first time interval.

[0025] If the current power supply is greater than the power supply previously acquired, the control subsystem sends an opening increase signal to the control valve based on the absolute value of the difference between the current power supply and the previous power supply and a preset opening adjustment ratio.

[0026] If the current power supply is equal to the power supply previously obtained, then the current opening of the control valve is maintained.

[0027] If the current power supply is less than the power supply previously acquired, the control subsystem sends an opening reduction signal to the control valve based on the absolute value of the difference between the current power supply and the previous power supply and a preset opening adjustment ratio.

[0028] Optionally, the control subsystem acquires the pressure of the hydrogen buffer tank of the hydrogen buffer subsystem, and adjusts the pump pressure of the booster pump of the hydrogen buffer subsystem according to the pressure, including:

[0029] The control subsystem acquires the pressure inside the hydrogen buffer tank at preset second time intervals.

[0030] If the current pressure is less than the preset pressure threshold, the control subsystem sends a pump pressure increase signal to the booster pump.

[0031] If the current pressure is equal to the preset pressure threshold, then the current pump pressure of the booster pump is maintained.

[0032] If the current pressure is greater than the preset pressure threshold, the control subsystem sends a pump pressure reduction signal to the booster pump.

[0033] Optionally, adjusting the hydrogen production rate of the hydrogen supply subsystem according to the pressure includes:

[0034] If the current pressure is less than the preset pressure threshold, the control subsystem sends a signal to the hydrogen supply subsystem to slow down the hydrogen production rate.

[0035] If the current pressure is equal to the preset pressure threshold, then the current hydrogen production rate of the hydrogen supply subsystem is maintained.

[0036] If the current pressure is greater than the preset pressure threshold, the control subsystem sends a signal to the hydrogen supply subsystem to increase the hydrogen production rate.

[0037] As can be seen from the above technical solutions, the present invention has the following advantages:

[0038] This invention provides a hydrogen fuel cell system and its control method. The hydrogen fuel cell system includes a hydrogen supply subsystem, a hydrogen buffer subsystem, an SOFC fuel cell system, and a control subsystem. The hydrogen buffer subsystem includes a booster pump, a hydrogen buffer tank, and a control valve. By acquiring the power supply of the SOFC fuel cell system and the pressure changes of the hydrogen buffer tank, the pump pressure of the booster pump, the opening degree of the control valve, and the hydrogen production rate of the hydrogen supply subsystem are adjusted. This achieves dynamic adjustment of the hydrogen consumption of the hydrogen fuel cell system, avoids hydrogen waste, and reduces system operating costs. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0040] Figure 1 This is a schematic diagram of the structure of a hydrogen fuel cell system provided in an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of the structure of a hydrogen fuel cell system provided in an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of the structure of a hydrogen fuel cell system provided in an embodiment of the present invention;

[0043] Figure 4 A flowchart illustrating the steps of a control method for a hydrogen fuel cell system provided in an embodiment of the present invention. Detailed Implementation

[0044] This invention provides a hydrogen fuel cell system and its control method, which solves the technical problem of high system operating costs caused by hydrogen waste in existing hydrogen fuel cell systems.

[0045] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0046] Please see Figures 1 to 3 Embodiment 1 of the present invention provides a hydrogen fuel cell system, including: a hydrogen supply subsystem 1, a hydrogen buffer subsystem 2, an SOFC fuel cell system 3, and a control subsystem 4;

[0047] Hydrogen buffer subsystem 2 includes a booster pump 21, a hydrogen buffer tank 22, and a control valve 23;

[0048] The hydrogen outlet of the hydrogen supply subsystem 2 is connected to the hydrogen inlet of the booster pump 21, the hydrogen outlet of the booster pump 21 is connected to the hydrogen inlet of the hydrogen buffer tank 22, the hydrogen outlet of the hydrogen buffer tank 22 is connected to the hydrogen inlet of the control valve 23, and the hydrogen outlet of the control valve 23 is connected to the hydrogen inlet of the SOFC fuel cell system 3.

[0049] The control subsystem 4 is electrically connected to the hydrogen supply subsystem 1, the SOFC fuel electronic system 3, the booster pump 21, the hydrogen buffer tank 22, and the control valve 23, respectively.

[0050] It is understandable that the SOFC fuel cell system 3 uses an SOFC stack 31 for power generation. The SOFC stack 31, short for Solid Oxide Fuel Cell Stack, is a new type of efficient and environmentally friendly energy conversion technology that converts chemical energy into electrical energy. It combines fuels such as hydrogen and natural gas with oxygen to produce electricity and water, while generating virtually no harmful emissions. The SOFC stack 31 mainly consists of a substrate, anode, cathode, electrolyte, and current collector. When hydrogen or other fuel enters the anode, it undergoes catalysis, ionizing into negative electrons and positive oxygen ions. These ions move along the conductive paths of the electrodes and electrolyte, respectively, and recombine at the cathode, thus forming an electric current. The SOFC stack 31 has advantages such as high efficiency, environmental friendliness, distributed operation, continuous operation, and high reliability, making it suitable for power generation, industrial hydrogen production, aviation, rockets, and other fields.

[0051] In the hydrogen buffer subsystem 2, the booster pump 21 is used to pressurize the hydrogen output from the hydrogen supply subsystem 1 and force the hydrogen into the hydrogen buffer tank 22; the hydrogen buffer tank 22 is used to temporarily store the hydrogen output from the hydrogen supply subsystem 1; the control valve 23 is used to receive the control signal from the control subsystem 4 and control the flow rate of hydrogen entering the SOFC fuel-electronic system 3 by adjusting the valve opening, thereby controlling the amount of hydrogen supplied to the SOFC fuel-electronic system 3.

[0052] The control subsystem 4 may include a controller, which is electrically connected to the hydrogen supply subsystem 1, the SOFC fuel cell system 3, the booster pump 21, the hydrogen buffer tank 22, and the control valve 23. Therefore, the control system 4 obtains the operating data information of the above modules and sends control signals to the above modules through the controller to dynamically adjust the hydrogen consumption of the hydrogen fuel cell system, thereby avoiding hydrogen waste and reducing system operating costs. For example, the control subsystem 4 can obtain the power supply change signal of the SOFC fuel cell system 3 through the controller 41, adjust the control valve 23 of the hydrogen buffer subsystem 2, and thus adjust the hydrogen flow rate into the SOFC stack 31; the control subsystem 4 can obtain the pressure change signal of the hydrogen buffer tank 22 of the hydrogen buffer subsystem 2 through the controller 41, control the pressure applied to the hydrogen output by the booster pump 21, and adjust the relevant parameters of the hydrogen production rate of the hydrogen supply subsystem 1 to control the operation of hydrogen production by the hydrogen supply subsystem 1.

[0053] In a preferred embodiment, the hydrogen fuel cell system further includes a waste heat recovery subsystem 55;

[0054] The SOFC fuel cell system 3 includes an SOFC stack 31 and a heat exchanger 32;

[0055] The hydrogen outlet of control valve 23 is connected to the hydrogen inlet of SOFC stack 31, the exhaust outlet of SOFC stack 31 is connected to the exhaust inlet of heat exchanger 32, the working fluid outlet of heat exchanger 32 is connected to the working fluid inlet of waste heat recovery subsystem 5, and the working fluid outlet of waste heat recovery subsystem 5 is connected to the heating pipe of hydrogen supply subsystem 1.

[0056] It should be noted that since the SOFC fuel cell system 3 operates at a very high temperature, typically around 1000K, and the exhaust gas temperature is not much different from its operating temperature, it possesses high-grade thermal energy. Therefore, waste heat recovery from its exhaust gas is essential to improve the system's energy utilization rate. One approach to waste heat recovery is to use a portion of the exhaust gas from the SOFC fuel cell system 3 for heating or hot water supply, while using the remainder to heat the hydrogen supply subsystem 1. However, the exhaust gas temperature of the SOFC fuel cell system 3 is as high as 1000K (726.85℃), far exceeding the reaction temperature of the hydrogen supply subsystem 1 (e.g., the suitable temperature for methanol reforming to produce hydrogen is 250℃~400℃), which is detrimental to the hydrogen production reaction in the hydrogen supply subsystem 1 and may even cause deterioration and decomposition of the working fluid in the hydrogen supply subsystem 1. Therefore, a heat exchanger 32 and a waste heat recovery subsystem 5 are introduced to recover and utilize the waste heat from the exhaust gas. After absorbing the energy of the exhaust gas output from the SOFC fuel cell system 3, the heat exchange medium in heat exchanger 32 enters the waste heat recovery subsystem 5 from the working medium inlet for energy conversion.

[0057] Furthermore, the waste heat recovery subsystem 5 includes a compressor 51 and a gas turbine 52;

[0058] The working fluid outlet of the SOFC gas-electric system 3 is connected to the working fluid inlet of the compressor 51, the working fluid outlet of the compressor 51 is connected to the working fluid inlet of the gas turbine (GT) 52, and the working fluid outlet of the gas turbine 52 is connected to the heating pipe of the hydrogen supply subsystem 1.

[0059] It is understandable that the heat exchange medium in heat exchanger 32 can be the exhaust gas generated by SOFC stack 31, which contains unreacted CO and H2, and can be reused in gas turbine 52. The high-temperature heat exchange medium output from the working medium outlet of SOFC fuel cell system 3 enters the waste heat recovery subsystem 5 and is first compressed in compressor 51. The compressed high-temperature and high-pressure working medium enters the combustion chamber of gas turbine 52 and is heated in one step. Since the content of unreacted CO and H2 in the high-temperature working medium is small and it is mixed with the products CO2 and H2O, it is not easy to ignite. A small amount of fuel can be added here to assist combustion. The high-temperature and high-pressure working medium after combustion and heating enters the gas turbine of gas turbine 52 to expand and do work. The expanded working medium enters the heating pipe of hydrogen supply subsystem 1 from gas turbine 52 to provide temperature conditions for hydrogen production reaction in hydrogen supply subsystem 1. The SOFC gas-electric system 3, compressor 51 and gas turbine 52 can form an SOFC-GT with a Brayton cycle structure, which can increase the energy utilization efficiency of the entire system from 40% to 62%.

[0060] Furthermore, the waste heat recovery subsystem 5 also includes a supercritical carbon dioxide cycle power generation module 53 connected between the gas turbine 52 and the hydrogen supply subsystem 1.

[0061] Since the temperature of the working fluid flowing out of the gas turbine 52 is still as high as 700K (426.85℃) after the SOFC exhaust gas recovers some heat and converts it into electrical energy through the compressor 51 and the gas turbine 52, which is still higher than the reaction temperature of the hydrogen supply subsystem 1, a supercritical carbon dioxide cycle power generation module 53 is further introduced to recover and utilize the waste heat. The waste heat recovery efficiency is maximized by using the recompression supercritical carbon dioxide (S-CO2) cycle.

[0062] The hydrogen supply subsystem 1 can use methanol or ammonia as the hydrogen production feedstock. In a preferred embodiment, the hydrogen supply subsystem 1 uses methanol as the hydrogen production feedstock, and includes a methanol-water solution storage tank 11, a methanol-water solution vaporizer 12, a methanol-water vapor reformer 13, and a hydrogen separator 14;

[0063] The methanol-water solution outlet of the methanol-water solution storage tank 11 is connected to the methanol-water solution inlet of the methanol-water solution vaporizer 12. The methanol-water vapor outlet of the methanol-water solution vaporizer 12 is connected to the methanol-water vapor inlet of the methanol-water vapor reformer 13. The reformed gas outlet of the methanol-water vapor reformer 13 is connected to the reformed gas inlet of the hydrogen separator 14. The hydrogen outlet of the hydrogen separator 14 is connected to the hydrogen inlet of the booster pump 21.

[0064] Understandably, the methanol-water solution storage tank 11 is used to store the reforming feedstock for hydrogen production, which is a methanol / water mixture. The methanol-water solution vaporizer 12 is used to perform high-temperature vaporization of the methanol / water mixture. The vaporizer 12 is heated to 230°C using the heat from the catalytic combustion of the combustion mixture. The methanol / water mixture stored in the methanol-water solution storage tank 11 is then introduced and vaporized under the heat provided by the vaporizer 12 to obtain methanol-water vapor, bringing it to the necessary state for participation in the reforming process for hydrogen production. The methanol-water vapor reformer 13 is used to reform the methanol-water vapor to produce hydrogen using a methanol reforming catalyst under the heat provided by the methanol-water solution vaporizer 12 and / or the waste heat recovery subsystem 5, producing hydrogen-rich reformed gas. The methanol reforming catalyst can be a copper-based catalyst Cu / ZnO / Al2O3 or a noble metal palladium-based catalyst Pd / Al2O3. The hydrogen separator 14 can be a PSA (Pressure Swing Adsorption) purification device or a TSA (Temperature Swing Adsorption) device. Adsorption purification equipment, PSA purification equipment and TSA purification equipment can separate hydrogen from hydrogen-rich reformed gas by adsorbing hydrogen through the pore structure of adsorbent materials (such as activated carbon).

[0065] In another preferred embodiment, the hydrogen supply subsystem 1 uses ammonia as the hydrogen production raw material, and the hydrogen supply subsystem 1 includes an ammonia storage tank 15, an ammonia cracking hydrogen generator 16, and a hydrogen separator 14.

[0066] The ammonia output end of the ammonia storage tank 15 is connected to the ammonia input end of the ammonia cracking hydrogen generator 16, the hydrogen / nitrogen mixed gas output end of the ammonia cracking hydrogen generator 16 is connected to the hydrogen / nitrogen mixed gas input end of the hydrogen separator 14, and the hydrogen outlet of the hydrogen separator 14 is connected to the hydrogen inlet of the booster pump 21.

[0067] Understandably, the ammonia storage tank 15 is used to store ammonia, the raw material for hydrogen production; the ammonia cracking hydrogen generator 16 is used to react ammonia with a metal catalyst or a nitride catalyst at high temperature, and the ammonia decomposes into a mixture of hydrogen and nitrogen at high temperature; the hydrogen separator 14 is used to separate the mixture of hydrogen and nitrogen to obtain hydrogen, and can be a PSA purification device or a TSA purification device.

[0068] Embodiment 2 of the present invention provides a control method for a hydrogen fuel cell system as described in any of the above system embodiments, involving a hydrogen supply subsystem 1, a hydrogen buffer subsystem 2, an SOFC fuel cell system 3, and a control subsystem 4 of the hydrogen fuel cell system; the control method includes the following steps:

[0069] Step 401: Obtain the power supply of SOFC fuel cell system 3 through control subsystem 4, and adjust the opening of control valve 23 of hydrogen buffer subsystem 2 according to the power supply change signal;

[0070] Step 402: Obtain the pressure of the hydrogen buffer tank 22 of the hydrogen buffer subsystem through the control subsystem 4, and adjust the pump pressure of the booster pump 21 of the hydrogen buffer subsystem 2 and the hydrogen production rate of the hydrogen supply subsystem 1 according to the pressure.

[0071] Understandably, by obtaining the power supply of the SOFC fuel cell system and the pressure changes of the hydrogen buffer tank 22, the pump pressure of the booster pump 21, the opening of the control valve 23, and the hydrogen production rate of the hydrogen supply subsystem 1 are adjusted, thereby achieving dynamic adjustment of the hydrogen consumption of the hydrogen fuel cell system, avoiding hydrogen waste, and reducing system operating costs.

[0072] In a preferred embodiment, step 401 specifically includes the following sub-steps:

[0073] S11. The power supply of the SOFC fuel cell system 3 is obtained by the control subsystem 4 at a preset first time interval;

[0074] S12. If the current power supply is greater than the power supply obtained last time, the control subsystem 4 sends an opening increase signal to the control valve 23 based on the absolute value of the difference between the current power supply and the power supply obtained last time and the preset opening adjustment ratio.

[0075] S13. If the current power supply obtained is equal to the power supply obtained last time, then maintain the current opening of the control valve 23.

[0076] S14. If the current power supply is less than the power supply obtained last time, the control subsystem 4 sends an opening reduction signal to the control valve 23 based on the absolute value of the difference between the current power supply and the power supply obtained last time and the preset opening adjustment ratio.

[0077] It should be noted that the preset opening adjustment ratio, i.e. the correspondence between the change in power supply and the change in the opening of control valve 23, can be set according to the relationship between the change in power supply, the change in the opening of control valve 23, and the change in the flow rate of hydrogen entering the SOFC fuel cell system 3.

[0078] In a preferred embodiment, step 402, which involves obtaining the pressure of the hydrogen buffer tank 22 of the hydrogen buffer subsystem through the control subsystem 4 and adjusting the pump pressure of the booster pump 21 of the hydrogen buffer subsystem according to the pressure, includes the following sub-steps:

[0079] S21. The pressure inside the hydrogen buffer tank 22 is obtained by the control subsystem 4 at a preset second time interval;

[0080] S22. If the current pressure is less than the preset pressure threshold, the control subsystem 4 sends a pump pressure increase signal to the booster pump 21.

[0081] S23. If the current pressure is equal to the preset pressure threshold, then maintain the current pump pressure of the booster pump 21.

[0082] S24. If the current pressure is greater than the preset pressure threshold, the control subsystem 4 sends a pump pressure reduction signal to the booster pump 21.

[0083] It should be noted that adjusting the pump pressure of booster pump 21 can change the pressure applied by booster pump 21 to the hydrogen output of hydrogen supply subsystem 1; the preset pressure threshold can be set according to production experience.

[0084] In a preferred embodiment, step 402, adjusting the hydrogen production rate of the hydrogen supply subsystem 1 according to the pressure, includes the following sub-steps:

[0085] S31. If the current pressure is less than the preset pressure threshold, a hydrogen production rate slowdown signal is sent from the control subsystem 4 to the hydrogen supply subsystem 1.

[0086] S32. If the current pressure is equal to the preset pressure threshold, then maintain the current hydrogen production rate of the hydrogen supply subsystem 1.

[0087] S33. If the current pressure is greater than the preset pressure threshold, the control subsystem 4 sends a signal to the hydrogen supply subsystem 1 to increase the hydrogen production rate.

[0088] It should be noted that after receiving a signal that the hydrogen production rate has slowed down, the hydrogen supply subsystem 1 can adjust its own hydrogen production rate by appropriately reducing the supply of hydrogen production raw materials, lowering the pressure of the reaction environment, and reducing the amount of catalyst. After receiving a signal that the hydrogen production rate has increased, it can adjust its own hydrogen production rate by appropriately increasing the supply of hydrogen production raw materials, increasing the pressure of the reaction environment, and increasing the amount of catalyst, until the pressure in the hydrogen buffer tank 22 equals the preset pressure threshold.

[0089] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, subsystems, and modules described above can be referred to the corresponding processes in the method embodiments, and will not be repeated here.

[0090] In the embodiments provided in this application, it should be understood that the disclosed systems, subsystems, modules, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0091] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0092] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0093] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0094] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydrogen fuel cell system characterized by comprising: This includes: a hydrogen supply subsystem, a hydrogen buffer subsystem, an SOFC fuel cell system, a control subsystem, and a waste heat recovery subsystem; The hydrogen buffer subsystem includes a booster pump, a hydrogen buffer tank, and a control valve; The SOFC fuel cell system includes an SOFC stack and a heat exchanger; The waste heat recovery subsystem includes a compressor and a gas turbine; The hydrogen outlet of the booster pump is connected to the hydrogen inlet of the hydrogen buffer tank, and the hydrogen outlet of the hydrogen buffer tank is connected to the hydrogen inlet of the control valve. The hydrogen outlet of the control valve is connected to the hydrogen inlet of the SOFC stack, and the exhaust outlet of the SOFC stack is connected to the exhaust inlet of the heat exchanger. The working fluid outlet of the heat exchanger is connected to the working fluid inlet of the compressor, the working fluid outlet of the compressor is connected to the working fluid inlet of the gas turbine, and the working fluid outlet of the gas turbine is connected to the heating pipe of the hydrogen supply subsystem. The hydrogen supply subsystem includes a methanol-water solution storage tank, a methanol-water solution vaporizer, a methanol-water vapor reformer, and a hydrogen separator. The methanol-water solution output of the methanol-water solution storage tank is connected to the methanol-water solution input of the methanol-water solution vaporizer. The methanol-water vapor output of the methanol-water solution vaporizer is connected to the methanol-water vapor input of the methanol-water vapor reformer. The reformed gas output of the methanol-water vapor reformer is connected to the reformed gas input of the hydrogen separator. The hydrogen outlet of the hydrogen separator is connected to the hydrogen inlet of the booster pump. Alternatively, the hydrogen supply subsystem includes an ammonia storage tank, an ammonia cracking hydrogen generator, and a hydrogen separator. The ammonia output of the ammonia storage tank is connected to the ammonia input of the ammonia cracking hydrogen generator. The hydrogen / nitrogen mixed gas output of the ammonia cracking hydrogen generator is connected to the hydrogen / nitrogen mixed gas input of the hydrogen separator. The hydrogen outlet of the hydrogen separator is connected to the hydrogen inlet of the booster pump. The control subsystem is electrically connected to the hydrogen supply subsystem, the SOFC fuel cell system, the booster pump, the hydrogen buffer tank, and the control valve, respectively.

2. The hydrogen fuel cell system of claim 1, wherein The waste heat recovery subsystem also includes a supercritical carbon dioxide cycle power generation module connected between the gas turbine and the hydrogen supply subsystem.

3. A control method of a hydrogen fuel cell system according to any one of claims 1 to 2, characterized by, The hydrogen supply subsystem, hydrogen buffer subsystem, SOFC fuel cell system, and control subsystem of the aforementioned hydrogen fuel cell system are involved; the control method includes: The control subsystem obtains the power supply of the SOFC fuel cell system and adjusts the opening of the control valve of the hydrogen buffer subsystem according to the power supply change signal. The control subsystem obtains the pressure of the hydrogen buffer tank of the hydrogen buffer subsystem and adjusts the pump pressure of the booster pump of the hydrogen buffer subsystem and the hydrogen production rate of the hydrogen supply subsystem according to the pressure.

4. The control method according to claim 3, characterized by The step of obtaining the power supply of the SOFC fuel cell system through the control subsystem and adjusting the opening of the control valve of the hydrogen buffer subsystem according to the power supply change signal includes: The control subsystem obtains the power supply of the SOFC fuel cell system at a preset first time interval. If the current power supply is greater than the power supply previously acquired, the control subsystem sends an opening increase signal to the control valve based on the absolute value of the difference between the current power supply and the previous power supply and a preset opening adjustment ratio. If the current power supply is equal to the power supply previously obtained, then the current opening of the control valve is maintained. If the current power supply is less than the power supply previously acquired, the control subsystem sends an opening reduction signal to the control valve based on the absolute value of the difference between the current power supply and the previous power supply and a preset opening adjustment ratio.

5. The control method according to claim 3, characterized by, The control subsystem acquires the pressure of the hydrogen buffer tank of the hydrogen buffer subsystem and adjusts the pump pressure of the booster pump of the hydrogen buffer subsystem according to the pressure, including: The control subsystem acquires the pressure inside the hydrogen buffer tank at preset second time intervals. If the current pressure is less than the preset pressure threshold, the control subsystem sends a pump pressure increase signal to the booster pump. If the current pressure is equal to the preset pressure threshold, then the current pump pressure of the booster pump is maintained. If the current pressure is greater than the preset pressure threshold, the control subsystem sends a pump pressure reduction signal to the booster pump.

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