Solid ammonia SOFC-PEMFC-GT hybrid power generation system and operation method thereof

Abstract

The present invention provides a solid ammonia SOFC-PEMFC-GT hybrid power generation system and its operating method, including a solid ammonia storage-hydrogen production composite module, a high-temperature proton exchange membrane fuel cell, a solid oxide fuel cell, a combustion chamber, and a turbine; the solid ammonia storage-hydrogen production composite module is connected to a purifier for purifying hydrogen, the purifier is respectively connected to the high-temperature proton exchange membrane fuel cell and the solid oxide fuel cell, and the tail gas output ends of the high-temperature proton exchange membrane fuel cell and the solid oxide fuel cell are respectively connected to the input end of the combustion chamber; the combustion chamber is connected to the turbine, and the turbine is connected to a generator. The present invention realizes low-temperature start-up of the solid oxide fuel cell during the startup phase; during the stable operation phase, through efficient co-combustion in the combustion chamber, high-temperature exhaust gas is used to achieve deep chemical heat recovery, and the turbine drives the generator to generate electricity, thereby realizing an efficient, reliable, and green hybrid power generation cycle.

Description

Technical Field

[0001] The present invention relates to the field of power generation technology, and in particular to a solid ammonia SOFC-PEMFC-GT hybrid power generation system and an operation method thereof. Background Art

[0002] Current hydrogen storage methods can be divided into physical hydrogen storage and chemical hydrogen storage. Physical hydrogen storage includes high-pressure hydrogen cylinders and liquid hydrogen. The liquefaction of hydrogen at extremely low temperatures has the problem of high energy consumption. In addition, when the storage environment conditions vary greatly, this method also has certain safety risks, making physical hydrogen storage unfriendly for transportation vehicles such as ships. In terms of chemical hydrogen storage, ammonia is considered to be an effective hydrogen carrier and has gradually attracted the attention of countries such as the European Union and Japan. According to a report by the International Energy Agency, it is expected that by 2050, ammonia fuel will account for 44% of the total fuel volume in the shipping industry.

[0003] Hydrogen power generation technology can be categorized into hydrogen engines and hydrogen-fueled fuel cells. Hydrogen engines have low ignition energy, which can easily lead to abnormal combustion phenomena such as backfire and detonation, and are currently still in the research and development stage. Fuel cells can be categorized into solid oxide fuel cells, proton exchange membrane fuel cells, and alkaline fuel cells, with the first two being the more mature fuel cells. Solid oxide fuel cells (SOFCs) utilize exhaust waste heat as a heat source to decompose ammonia fuel to produce hydrogen. High-temperature waste heat can also be coupled with waste heat power generation. These technologies offer advantages such as high power generation efficiency, low hydrogen purity requirements, and zero emissions, making SOFC waste heat utilization technology a current research hotspot. For example, patent CN118270212A proposes a SOFC-GT-coupled ship propulsion system and variable load operation method. High-temperature exhaust gas from the SOFC outlet drives a gas turbine, improving the system's overall energy efficiency. For example, patent CN113506902A proposes a hybrid system of a solid oxide fuel cell and a proton exchange membrane fuel cell using ammonia as fuel. The system purifies the unreacted fuel gas at the anode outlet of the solid oxide fuel cell through a separator to form high-purity hydrogen, which is used as fuel for the downstream proton exchange membrane fuel cell, thereby achieving efficient fuel utilization. Although this patent reuses the hydrogen from the exhaust gas of the solid oxide fuel cell, it ignores the fact that when the system operating conditions change, unreacted fuel gas may also remain at the anode outlet of the downstream proton exchange membrane fuel cell. In addition, this patent mainly studies the improvement of fuel utilization. Considering that the exhaust temperature of solid oxide fuel cells can reach 600-1000°C and the exhaust temperature of high-temperature proton exchange membrane fuel cells can reach 350°C, further research is needed to comprehensively utilize the waste heat of the fuel cell exhaust and the unreacted fuel gas.

[0004] Based on this, it is necessary to propose a solid ammonia SOFC-PEMFC-GT hybrid power generation system that can effectively solve the existing problems of insufficient fuel utilization, difficulty in low-temperature start-up of solid oxide fuel cells, and low system energy efficiency, thereby effectively improving the energy efficiency of the system power generation cycle. Summary of the Invention

[0005] In view of the defects in the prior art, the object of the present invention is to provide a solid ammonia SOFC-PEMFC-GT hybrid power generation system and an operation method thereof.

[0006] According to the present invention, a solid ammonia SOFC-PEMFC-GT hybrid power generation system is provided, comprising: a solid ammonia storage-hydrogen production composite module, a high-temperature proton exchange membrane fuel cell, a solid oxide fuel cell, a combustion chamber, and a turbine;

[0007] The output end of the solid-state ammonia storage-hydrogen production composite module is connected to a purifier for purifying hydrogen, the output end of the purifier is respectively connected to the input end of the high-temperature proton exchange membrane fuel cell and the solid oxide fuel cell, the tail gas output ends of the high-temperature proton exchange membrane fuel cell and the solid oxide fuel cell are respectively connected to the input end of the combustion chamber, and the retained gas output end of the purifier is respectively connected to the input end of the solid-state ammonia storage-hydrogen production composite module and the combustion chamber;

[0008] The output end of the combustion chamber is connected to a turbine, and the turbine is connected to a generator;

[0009] The exhaust gas output end of the turbine is communicated with a solid ammonia storage-hydrogen production composite module and a solid oxide fuel cell respectively, and both the solid ammonia storage-hydrogen production composite module and the solid oxide fuel cell are provided with an exhaust gas outlet.

[0010] Preferably, a regenerator 1 is provided between the purifier and the high-temperature proton exchange membrane fuel cell, the solid-state ammonia storage-hydrogen production composite module, the purifier, the regenerator 1 and the anode input end of the high-temperature proton exchange membrane fuel cell are connected in sequence, a pressure reducing valve is provided between the regenerator 1 and the anode input end of the high-temperature proton exchange membrane fuel cell, the regenerator 1 is connected to an air inlet, and the air inlet, the regenerator 1 and the cathode input end of the high-temperature proton exchange membrane fuel cell are connected in sequence.

[0011] Preferably, the cathode tail gas output end of the high-temperature proton exchange membrane fuel cell is connected to a water vapor separator, the hydrogen output end of the water vapor separator and the anode tail gas output end of the high-temperature proton exchange membrane fuel cell merge into an tail gas flow path, and a one-way control valve is provided on the tail gas flow path.

[0012] Preferably, a regenerator 2 is provided between the purifier and the solid oxide fuel cell, the solid-state ammonia storage-hydrogen production composite module, the purifier, the regenerator 2 and the anode input end of the solid oxide fuel cell are connected in sequence, the cathode input end of the solid oxide fuel cell is connected to the regenerator 3, the input end of the regenerator 3 is connected to the compressor, and the compressor is connected to the air inlet.

[0013] Preferably, the anode tail gas output end of the solid oxide fuel cell is connected to a water vapor separator, the cathode tail gas output end of the solid oxide fuel cell is connected to the regenerator three, the hydrogen output end of the water vapor separator and the cathode tail gas output end of the regenerator three are merged into an exhaust gas flow path, and the exhaust gas flow path is connected to the regenerator two.

[0014] Preferably, the combustion chamber is further provided with an air inlet and a pressure regulating interface, the air inlet is connected to a one-way control valve, the pressure regulating interface is connected to a pressure regulator, and the pressure regulator is connected to a compressor.

[0015] Preferably, the compressor is connected to an electric starter, and the compressor is coaxially connected to the turbine.

[0016] According to the present invention, an operating method of a solid ammonia SOFC-PEMFC-GT hybrid power generation system is provided, which is applied to the above-mentioned solid ammonia SOFC-PEMFC-GT hybrid power generation system and includes a startup operation phase and a stable operation phase.

[0017] Preferably, the startup operation phase includes the following steps:

[0018] Step 1: After heating, the solid-state ammonia storage-hydrogen production composite module realizes ammonia desorption and thermal decomposition of ammonia from the solid amino group to obtain a mixed gas;

[0019] In step 2, the mixed gas passes through the purifier, regenerator 1, and pressure reducing valve to achieve purification, cooling, and decompression. The hydrogen then enters the anode of the high-temperature proton exchange membrane fuel cell. At the same time, the air passes through the air inlet and regenerator 1 to achieve temperature increase and then enters the cathode of the high-temperature proton exchange membrane fuel cell. The two gases undergo redox reactions at the anode and cathode of the high-temperature proton exchange membrane fuel cell, respectively, to achieve power generation.

[0020] Step 3: The anode tail gas of the high-temperature proton exchange membrane fuel cell and the cathode tail gas that has passed through the water vapor separator are mixed with the retentate gas of the purifier and then flow into the combustion chamber;

[0021] In step 4, the gas after combustion enters the three-way valve through the turbine and is divided into two paths. One path flows into the solid ammonia storage-hydrogen production composite module for heating, and the other path is first mixed with room temperature air at the three-way valve and then enters the solid oxide fuel cell for preheating.

[0022] Preferably, the stable operation stage includes the following steps:

[0023] Step 1: After heating, the solid-state ammonia storage-hydrogen production composite module realizes ammonia desorption and thermal decomposition of ammonia from the solid amino group to obtain a mixed gas;

[0024] Step 2: The mixed gas passes through the purifier and regenerator 2 and enters the anode of the solid oxide fuel cell as fuel. The air is heated and pressurized by the compressor and regenerator 3 and then flows into the cathode of the solid oxide fuel cell.

[0025] Step 3: The cathode outflow gas of the solid oxide fuel cell is reheated in the regenerator 3, and then flows into the regenerator 2 together with the anode outflow gas that has passed through the water vapor separator, and then further mixed with the ammonia retained at the outlet of the purifier, and flows into the combustion chamber to be burned to generate exhaust gas;

[0026] In step 4, the exhaust gas flows into the turbine to achieve expansion and work, driving the generator to generate electricity. At the same time, the exhaust gas flowing out of the turbine flows into the solid ammonia storage-hydrogen production composite module and the solid oxide fuel cell respectively, ensuring that the temperature of the solid oxide fuel cell is stable within the preset range.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention, by providing a combustion chamber, can effectively reuse the chemical energy of the high-temperature proton exchange membrane fuel cell anode outlet gas, the solid oxide fuel cell anode outlet gas and the purifier retained gas, convert the chemical energy into thermal energy, and generate high-temperature exhaust gas, thereby utilizing the high-temperature exhaust gas to achieve chemical heat recovery in the ammonia decomposition hydrogen production process and the solid oxide fuel cell temperature rise process; by controlling the air flow rate flowing into the combustion chamber and by providing a water vapor separator to prevent water vapor from flowing into the combustion chamber, the fuel utilization rate of the system is effectively improved, and the chemical energy in the fuel is released to the maximum extent.

[0029] 2. The present invention can control the combustion temperature in the combustion chamber to meet the operating temperature requirements of the solid oxide fuel cell by adjusting the ammonia flow rate and hydrogen flow rate flowing into the combustion chamber; by adjusting the flow ratio of normal temperature air and high-temperature exhaust gas flowing out of the combustion chamber through the turbine, the exhaust gas temperature flowing into the solid oxide fuel cell is controlled in real time, so that the exhaust gas temperature can meet the gradual heating requirement of the solid oxide fuel cell during the low-temperature startup stage, thereby achieving efficient matching of the temperature required for the low-temperature startup of the solid oxide fuel cell.

[0030] 3. The present invention improves the comprehensive energy utilization efficiency of the system through the efficient coupling of solid oxide fuel cells, high-temperature proton exchange membrane fuel cells and turbines; during the low-temperature start-up stage of the solid oxide fuel cell, the high-temperature proton exchange membrane fuel cell serves as an auxiliary power generation device and can also provide the high-temperature waste heat required for the low-temperature start-up of the solid oxide fuel cell, thereby effectively improving the energy utilization efficiency of the system during the low-temperature start-up stage; during the stable operation stage of the solid oxide fuel cell, through the coaxial design of the turbine and the compressor, the turbine can drive the compressor to compress the air while utilizing the high-temperature and high-pressure exhaust gas expansion of the solid oxide fuel cell to generate electricity, reducing the power consumption of the compressor, thereby effectively improving the comprehensive energy utilization efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0032] Figure 1 This is a schematic diagram of a solid-state ammonia SOFC-PEMFC-GT hybrid power generation system mainly embodied in the present invention.

[0033] As shown in the figure: solid-state ammonia storage-hydrogen production composite module 1; purifier 2; regenerator 1 3; high-temperature proton exchange membrane fuel cell 4; solid oxide fuel cell 5; regenerator 2 6; water vapor separator 7; regenerator 3 8; pressure regulator 9; combustion chamber 10; compressor 11; turbine 12; generator 13; electric starter 14; pressure reducing valve 15; one-way control valve 16; three-way valve 17. DETAILED DESCRIPTION

[0034] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0035] like Figure 1As shown, a solid ammonia SOFC-PEMFC-GT hybrid power generation system provided by the present invention includes: a solid ammonia storage-hydrogen production composite module 1, a high-temperature proton exchange membrane fuel cell 4, a solid oxide fuel cell 5, a combustion chamber 10 and a turbine 12; the output end of the solid ammonia storage-hydrogen production composite module 1 is connected to a purifier 2 for purifying hydrogen, the output end of the purifier 2 is respectively connected to the input end of the high-temperature proton exchange membrane fuel cell 4 and the solid oxide fuel cell 5, the tail gas output ends of the high-temperature proton exchange membrane fuel cell 4 and the solid oxide fuel cell 5 are respectively connected to the input end of the combustion chamber 10, and the retained gas output end of the purifier 2 is respectively connected to the input end of the solid ammonia storage-hydrogen production composite module 1 and the combustion chamber 10; the output end of the combustion chamber 10 is connected to the turbine 12, and the turbine 12 is connected to a generator 13; the exhaust gas output end of the turbine 12 is respectively connected to the solid ammonia storage-hydrogen production composite module 1 and the solid oxide fuel cell 5, and both the solid ammonia storage-hydrogen production composite module 1 and the solid oxide fuel cell 5 are provided with exhaust gas discharge outlets.

[0036] The power generation system of the present application is divided into a startup operation stage and a system stable operation stage.

[0037] During the system startup phase, the solid-state ammonia storage-hydrogen production composite module 1 is heated to achieve ammonia desorption and thermal decomposition of the solid amino group, providing fuel for the high-temperature proton exchange membrane fuel cell 4, enabling it to generate electricity. Furthermore, the tail gas from the high-temperature proton exchange membrane fuel cell 4 flows into the combustion chamber 10 along with a portion of the retained gas from the purifier 2 for co-combustion to generate high-temperature, low-pressure gas. The flow rate ratio of the high-temperature gas to ambient temperature air is then adjusted in real time to control the temperature of the high-temperature air flowing into the solid oxide fuel cell 5, ensuring that it meets the temperature requirements of the solid oxide fuel cell 5 during the low-temperature startup phase.

[0038] During the system's stable operation phase, solid-state ammonia storage-hydrogen production module 1 is heated to desorb ammonia from the solid amino group and thermally decompose it, providing fuel for solid oxide fuel cell 5, enabling it to generate electricity. Simultaneously, the high-temperature, high-pressure exhaust gas from solid oxide fuel cell 5 flows into combustion chamber 10 along with some of the retained gas from purifier 2, where it is mixed and combusted to generate high-temperature, high-pressure gas. This gas then drives turbine 12 to expand and generate power, driving generator 13 to generate electricity.

[0039] The solid-state ammonia storage-hydrogen production composite module 1 is heated to achieve ammonia desorption and thermal decomposition of the solid amino group, thereby obtaining a high-temperature and high-pressure mixed gas of hydrogen / nitrogen / ammonia, which provides fuel for the solid oxide fuel cell 5 and the high-temperature proton exchange membrane fuel cell 4.

[0040] This application can solve the existing problems of insufficient fuel utilization, difficulty in low-temperature startup of solid oxide fuel cells, and low system energy efficiency. During the startup phase of this application, the system uses the high-temperature exhaust gas generated after the combustion of the high-temperature proton exchange membrane fuel cell 4 to achieve low-temperature startup of the solid oxide fuel cell 5. During the stable operation phase, the system uses the high-temperature exhaust gas to achieve deep chemical heat recovery through efficient co-combustion of the exhaust gas at the outlet of the solid oxide fuel cell 5 and part of the retained gas of the purifier 2, and drives the turbine 12 to expand and do work to drive the generator 13 to generate electricity, thereby realizing an efficient, reliable, and green SOFC-PEMFC-GT hybrid power generation cycle.

[0041] The purifier 2 is used to purify the hydrogen in the mixed gas flowing out of the solid ammonia storage-hydrogen production composite module 1, to prevent ammonia and other impurities in the mixed gas from flowing into the high-temperature proton exchange membrane fuel cell 4 and the solid oxide fuel cell 5, causing fuel cell poisoning. In addition, the retained gas in the purifier 2 includes ammonia and nitrogen, etc., and the flow rates of the gases flowing back to the solid ammonia storage-hydrogen production composite module 1 and flowing into the combustion chamber 10 are adjusted by controlling the three-way valve 17. The purifier 2 is used to purify the high-temperature and high-pressure mixed gas flowing out of the solid ammonia storage-hydrogen production composite module 1. This is because the fuel cell has high requirements for the purity of hydrogen, otherwise it is easy to cause fuel cell poisoning. However, the purifier 2 can generally only purify 90% of the hydrogen, so there is still a small amount of hydrogen and ammonia in the retained gas. The flow rates of the gases flowing back to the solid ammonia storage-hydrogen production composite module 1 and the combustion chamber 10 are controlled by the three-way valve 17, thereby achieving efficient utilization of the fuel.

[0042] A regenerator 3 is provided between the purifier 2 and the high-temperature proton exchange membrane fuel cell 4. The solid-state ammonia storage-hydrogen production hybrid module 1, the purifier 2, the regenerator 3, and the anode input of the high-temperature proton exchange membrane fuel cell 4 are sequentially connected. A pressure reducing valve 15 is provided between the regenerator 3 and the anode input of the high-temperature proton exchange membrane fuel cell 4. The regenerator 3 is connected to an air inlet, which is then sequentially connected to the air inlet, the regenerator 3, and the cathode input of the high-temperature proton exchange membrane fuel cell 4. The regenerator 3 is used to cool the high-temperature hydrogen anode gas after passing through the purifier 2 and to heat the incoming room-temperature air cathode gas. This ensures that the inflowing anode and cathode gas temperatures match those of the high-temperature proton exchange membrane fuel cell 4, thereby improving the operating efficiency of the fuel cell.

[0043] The cathode tail gas output end of the high-temperature proton exchange membrane fuel cell 4 is connected to the water vapor separator 7, and the hydrogen output end of the water vapor separator 7 and the anode tail gas output end of the high-temperature proton exchange membrane fuel cell 4 are merged into an exhaust gas flow path through a three-way valve 17, and a one-way control valve 16 is provided on the exhaust gas flow path. The exhaust gas flows into the combustion chamber 10 through the one-way control valve 16, the three-way valve 17 and other valves in turn.

[0044] A regenerator 2 6 is located between the purifier 2 and the solid oxide fuel cell 5. The solid-state ammonia storage-hydrogen production hybrid module 1, purifier 2, regenerator 2 6, and the anode input of the solid oxide fuel cell 5 are sequentially connected. The cathode input of the solid oxide fuel cell 5 is connected to regenerator 3 8, the input of which is connected to a compressor 11, which is connected to an air inlet. Regenerator 2 6 and regenerator 3 8 are respectively used to heat the high-temperature hydrogen anode gas after passing through the purifier 2 and the room-temperature air after being pressurized by the compressor 11. This ensures that the inflow temperatures of the anode and cathode gases match those of the solid oxide fuel cell 5, thereby improving the fuel cell's operating efficiency.

[0045] The anode tail gas output end of the solid oxide fuel cell 5 is connected to the water vapor separator 7, and the cathode tail gas output end of the solid oxide fuel cell 5 is connected to the regenerator three 8. The hydrogen output end of the water vapor separator 7 and the cathode tail gas output end of the regenerator three 8 merge into a high-temperature tail gas and merge into an exhaust gas flow path, and the exhaust gas flow path is connected to the regenerator two 6. The high-temperature tail gas passes through the regenerator two 6 and the retained gas purified by the purifier 2 and merges at the three-way valve 17, and then flows into the combustion chamber 10.

[0046] The water vapor separator 7 is used to separate the water vapor and hydrogen in the cathode tail gas of the high-temperature proton exchange membrane fuel cell 4 and the anode tail gas of the solid oxide fuel cell 5, to recycle the tail gas water vapor, and to prevent the water vapor from flowing into the combustion chamber 10 and reducing the combustion efficiency.

[0047] The combustion chamber 10 includes an exhaust gas inlet, an air inlet, a post-combustion gas outlet, and a pressure regulating port. The air inlet is connected to a one-way control valve 16, which controls the flow rate. The pressure regulating port is connected to a pressure regulator 9, which is in turn connected to a compressor 11. The pressure regulating port, connected to the pressure regulator 9 via the one-way control valve 16, controls the pressure within the combustion chamber 10 to match the pressure of the air compressed by the compressor 11, thereby ensuring that the high-temperature, high-pressure exhaust gas from the solid oxide fuel cell 5 can flow into the combustion chamber 10.

[0048] By controlling the ratio of ammonia and hydrogen flowing into the combustion chamber 10, the temperature of the high-temperature exhaust gas after combustion can be effectively controlled. This is because the combustion temperature of hydrogen is above 1700°C, the ignition temperature of ammonia is 653°C, the operating temperature of solid oxide fuel cells is 600-1000°C, and the operating temperature of solid-state ammonia storage-hydrogen production modules is 400-700°C. To meet the temperature requirements of different components, hydrogen and ammonia need to be mixed and burned in a certain ratio. In addition, when the temperature exceeds 800°C, the concentration of NOx gas produced by the combustion of ammonia will increase significantly. To this end, a catalyst can be added to the combustion chamber 10 to reduce the combustion temperature.

[0049] Compressor 11 is connected to an electric starter 14, which drives compressor 11 to compress and increase the pressure of air when the internal pressure of solid oxide fuel cell 5 has not yet reached a stable operating pressure. Compressor 11 is coaxially connected to turbine 12, and compressor 11 drives turbine 12 to expand and generate electricity.

[0050] The high-temperature, low-pressure exhaust gas at the outlet of the turbine 12 is divided into two branches via a three-way valve 17. In the first branch, the three-way valve 17, the solid oxide fuel cell 5, and the high-temperature exhaust gas outlet are connected in sequence. In the second branch, the three-way valve 17, the solid-state ammonia storage-hydrogen production composite module 1, and the high-temperature exhaust gas outlet are connected in sequence. The three-way valve 17 is used to adjust the flow ratio of normal temperature air and the high-temperature exhaust gas flowing out of the turbine 12, thereby controlling the exhaust gas temperature flowing into the solid oxide fuel cell 5 in real time, so that the exhaust gas temperature can meet the gradual heating requirement of the solid oxide fuel cell 5 during the low-temperature startup phase.

[0051] According to the present invention, an operating method of a solid ammonia SOFC-PEMFC-GT hybrid power generation system includes a startup operation phase and a stable operation phase.

[0052] The startup phase includes the following steps:

[0053] Step 1: After heating, the solid-state ammonia storage-hydrogen production composite module 1 is used to desorb ammonia from the solid amino group and thermally decompose the ammonia to obtain a mixed gas;

[0054] In step 2, the mixed gas passes through the purifier 2, the regenerator 3, and the pressure reducing valve 15 to achieve purification, cooling, and pressure reduction. The hydrogen then enters the anode of the high-temperature proton exchange membrane fuel cell 4. At the same time, the air passes through the air inlet and the regenerator 3 to achieve temperature increase and then enters the cathode of the high-temperature proton exchange membrane fuel cell 4. The two gases undergo redox reactions at the anode and cathode of the high-temperature proton exchange membrane fuel cell 4, respectively, to achieve power generation.

[0055] Step 3: The anode tail gas of the high-temperature proton exchange membrane fuel cell 4 and the cathode tail gas after passing through the water vapor separator 7 are mixed with the retentate gas of the purifier 2 and then flow into the combustion chamber 10;

[0056] In step 4, the gas after combustion enters the three-way valve 17 through the turbine 12 and is divided into two paths. One path flows into the solid ammonia storage-hydrogen production composite module 1 for heating, and the other path is first mixed with room temperature air at the three-way valve 17, and then enters the solid oxide fuel cell 5 for preheating.

[0057] When the system is in operation, the key components include: a solid-state ammonia storage-hydrogen production module 1, a high-temperature proton exchange membrane fuel cell 4, and a solid oxide fuel cell 5. After heating, the solid-state ammonia storage-hydrogen production module 1 desorbs ammonia from the solid amino group and thermally decomposes it, producing a high-temperature, high-pressure gas mixture of hydrogen, nitrogen, and ammonia. This high-temperature, high-pressure gas mixture passes through the purifier 2, regenerator 3, and pressure-reducing valve 15 for purification, cooling, and decompression before entering the anode of the high-temperature proton exchange membrane fuel cell 4. Simultaneously, air is heated through the air inlet and regenerator 3 before entering the cathode of the high-temperature proton exchange membrane fuel cell 4. The two gases then undergo redox reactions at the anode and cathode of the fuel cell, respectively, generating power. The anode exhaust from the high-temperature proton exchange membrane fuel cell 4 and the cathode exhaust from the water vapor separator 7 are then combined into a single flow path after the three-way valve 17. The gas flows through valves such as the one-way control valve 16 and the three-way valve 17, mixing with the stagnant gas from the purifier 2 before flowing into the combustion chamber 10. The high-temperature, low-pressure gas formed after combustion enters the three-way valve 17 through the turbine 12 and is divided into two paths. One path flows into the solid-state ammonia storage-hydrogen production composite module 1 for heating, and the other path is first mixed with room-temperature air in a certain proportion at the three-way valve 17 before entering the solid oxide fuel cell 5 for preheating. This is because the rapid temperature increase will cause a temperature gradient in the material inside the solid oxide fuel cell, which in turn induces thermal stress, which can easily damage the material inside the fuel cell and even cause cracks. Therefore, the solid oxide fuel cell needs to gradually increase from room temperature to the operating temperature of 600-1000°C during the low-temperature startup stage. To this end, it is necessary to control the flow ratio of room-temperature air and high-temperature gas in real time so that its temperature change meets the temperature requirements of the solid oxide fuel cell during the low-temperature startup stage.

[0058] The stable operation phase includes the following steps:

[0059] Step 1: After heating, the solid-state ammonia storage-hydrogen production composite module 1 is used to desorb ammonia from the solid amino group and thermally decompose the ammonia to obtain a mixed gas;

[0060] Step 2: The mixed gas passes through the purifier 2 and the regenerator 2 6 and enters the anode of the solid oxide fuel cell 5 as fuel. The air is heated and pressurized by the compressor 11 and the regenerator 3 8 and then flows into the cathode of the solid oxide fuel cell 5.

[0061] Step 3: The cathode outflow gas of the solid oxide fuel cell 5 is reheated in the regenerator 3 8 and then flows into the regenerator 2 6 together with the anode outflow gas that has passed through the water vapor separator 7. The gas is further mixed with the ammonia retained at the outlet of the purifier 2 and flows into the combustion chamber 10 for combustion to generate exhaust gas.

[0062] In step 4, the exhaust gas flows into the turbine 12 to achieve expansion work, driving the generator 13 to generate electricity. At the same time, the exhaust gas flowing out of the turbine 12 flows into the solid ammonia storage-hydrogen production composite module 1 and the solid oxide fuel cell 5 respectively, ensuring that the temperature of the solid oxide fuel cell 5 is stable within a preset range.

[0063] During the system's stable operation phase, key components include the solid-state ammonia storage-hydrogen production module 1, the solid oxide fuel cell 5, and the turbine 12. The high-temperature, high-pressure mixed gas from the solid-state ammonia storage-hydrogen production module 1 flows through the purifier 2 and regenerator 2 6 to the anode of the solid oxide fuel cell 5, providing fuel. The air is heated and pressurized by the compressor 11, three-way valve 17, and regenerator 3 8 before flowing into the cathode of the solid oxide fuel cell 5. The gas flowing out of the cathode of the solid oxide fuel cell is reheated with the inlet air through regenerator 3 8, then mixed with the gas at the cathode outlet through the three-way valve 17. It then flows into the regenerator 2 6 to reheat with the fuel at the cathode inlet. The exhaust gas from the solid oxide fuel cell 5, after extensive reheating, is further mixed with the residual ammonia gas at the outlet of the purifier 2 through the three-way valve 17. The exhaust gas then flows into the combustion chamber 10, where it is burned to generate even higher-temperature, high-pressure exhaust gas. This exhaust gas, without the assistance of the electric starter 14 for pressurization, flows directly into the turbine 12, where it expands and generates work, driving the generator 13 to generate electricity. At the same time, the high-temperature, low-pressure exhaust gas flowing out of the turbine 12 mainly flows into the solid-state ammonia storage-hydrogen production composite module 1 for heating, and a small part flows into the solid oxide fuel cell 5 to ensure that its temperature remains stable within a certain range when the operating parameters change.

[0064] The present application can effectively improve the fuel utilization rate of the system. By providing a combustion chamber 10, the present application can effectively reuse the chemical energy of the anode outlet gas of the high-temperature proton exchange membrane fuel cell 4, the anode outlet gas of the solid oxide fuel cell 5, and the retained gas of the purifier 2, converting the chemical energy into thermal energy to generate high-temperature exhaust gas, thereby utilizing the high-temperature exhaust gas to achieve chemical heat recovery in the ammonia decomposition hydrogen production process and the solid oxide fuel cell heating process. In addition, by controlling the air flow rate flowing into the combustion chamber 10 and preventing water vapor from flowing into the combustion chamber 10 by providing a water vapor separator 7, the fuel utilization rate of the system is effectively improved, and the chemical energy in the fuel is released to the maximum extent.

[0065] The present application can achieve efficient matching of the temperature required for low-temperature startup of the solid oxide fuel cell 5. By adjusting the flow rate of ammonia and hydrogen flowing into the combustion chamber 10, the present application can control the combustion temperature in the combustion chamber 10 to meet the operating temperature requirement of 600 to 1000°C of the solid oxide fuel cell 5. By adjusting the flow ratio of normal temperature air and high-temperature exhaust gas flowing out of the combustion chamber 10 through the turbine 12, the exhaust gas temperature flowing into the solid oxide fuel cell 5 is controlled in real time, so that the exhaust gas temperature can meet the gradual temperature increase requirement of the solid oxide fuel cell 5 during the low-temperature startup stage, thereby achieving efficient matching of the temperature required for low-temperature startup of the solid oxide fuel cell 5.

[0066] The present application can achieve efficient coupling of the solid oxide fuel cell 5, the high-temperature proton exchange membrane fuel cell 4 and the turbine 12, thereby improving the overall energy utilization efficiency of the system. During the low-temperature startup phase of the solid oxide fuel cell 5, the high-temperature proton exchange membrane fuel cell 4, as an auxiliary power generation device, can also provide the high-temperature waste heat required for the low-temperature startup of the solid oxide fuel cell 5, thereby effectively improving the energy utilization efficiency of the system during the low-temperature startup phase. During the stable operation phase of the solid oxide fuel cell 5, through the coaxial design of the turbine 12 and the compressor 11, the turbine 12 can also drive the compressor 11 to compress the air while utilizing the high-temperature and high-pressure exhaust gas expansion of the solid oxide fuel cell 5 to generate electricity, thereby reducing the power consumption of the compressor 11, thereby effectively improving the overall energy utilization efficiency of the system.

[0067] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0068] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A method for operating a solid ammonia SOFC-PEMFC-GT hybrid power generation system, characterized in that: An operation method including a startup operation phase and a stable operation phase is realized by using a solid ammonia SOFC-PEMFC-GT hybrid power generation system; The solid ammonia SOFC-PEMFC-GT hybrid power generation system comprises: a solid ammonia storage-hydrogen production composite module (1), a high-temperature proton exchange membrane fuel cell (4), a solid oxide fuel cell (5), a combustion chamber (10) and a turbine (12), wherein the solid ammonia storage-hydrogen production composite module (1) is heated to obtain a mixed gas of hydrogen / nitrogen / ammonia; The startup phase includes the following steps: Step 1: After heating, the solid-state ammonia storage-hydrogen production composite module (1) achieves ammonia desorption and thermal decomposition of the solid amino group to obtain a mixed gas; In step 2, the mixed gas passes through the purifier (2), the regenerator (3), and the pressure reducing valve (15) to achieve purification, cooling, and pressure reduction, and then the hydrogen enters the anode of the high-temperature proton exchange membrane fuel cell (4). At the same time, the air passes through the air inlet and the regenerator (3) to achieve temperature increase, and then enters the cathode of the high-temperature proton exchange membrane fuel cell (4). The two gases respectively undergo redox reactions at the anode and cathode of the high-temperature proton exchange membrane fuel cell (4), thereby achieving a power generation process. Step 3: The anode tail gas of the high-temperature proton exchange membrane fuel cell (4) and the cathode tail gas after passing through the water vapor separator (7) are mixed with the retentate gas of the purifier (2) and then flow into the combustion chamber (10); Step 4: The combusted gas enters the three-way valve (17) through the turbine (12) and is divided into two paths. One path flows into the solid ammonia storage-hydrogen production composite module (1) for heating, and the other path is first mixed with room temperature air at the three-way valve (17) and then enters the solid oxide fuel cell (5) for preheating. The stable operation phase includes the following steps: Step 1: After heating, the solid-state ammonia storage-hydrogen production composite module (1) achieves ammonia desorption and thermal decomposition of the solid amino group to obtain a mixed gas; Step 2: The mixed gas passes through the purifier (2) and the regenerator (6) and enters the anode of the solid oxide fuel cell (5) as fuel, and the air passes through the compressor (11) and the regenerator (8) to be heated and pressurized before flowing into the cathode of the solid oxide fuel cell (5); Step 3: The cathode outflow gas of the solid oxide fuel cell (5) is reheated in the regenerator 3 (8), and then flows into the regenerator 2 (6) together with the anode outflow gas that has passed through the water vapor separator (7), and then further mixed with the ammonia gas retained at the outlet of the purifier (2), and flows into the combustion chamber (10) to burn and generate exhaust gas; In step 4, the exhaust gas flows into the turbine (12) to achieve expansion work, driving the generator (13) to generate electricity. At the same time, the exhaust gas flowing out of the turbine (12) flows into the solid ammonia storage-hydrogen production composite module (1) and the solid oxide fuel cell (5) respectively, ensuring that the temperature of the solid oxide fuel cell (5) is stable within a preset range.

2. The operating method of the solid ammonia SOFC-PEMFC-GT hybrid power generation system according to claim 1, characterized in that: The output end of the solid-state ammonia storage-hydrogen production composite module (1) is connected to a purifier (2) for purifying hydrogen, the output end of the purifier (2) is respectively connected to the input ends of the high-temperature proton exchange membrane fuel cell (4) and the solid oxide fuel cell (5), the tail gas output ends of the high-temperature proton exchange membrane fuel cell (4) and the solid oxide fuel cell (5) are respectively connected to the input end of the combustion chamber (10), and the retained gas output end of the purifier (2) is respectively connected to the input ends of the solid-state ammonia storage-hydrogen production composite module (1) and the combustion chamber (10); The output end of the combustion chamber (10) is connected to a turbine (12), and the turbine (12) is connected to a generator (13); The exhaust gas output end of the turbine (12) is respectively connected to the solid ammonia storage-hydrogen production composite module (1) and the solid oxide fuel cell (5), and both the solid ammonia storage-hydrogen production composite module (1) and the solid oxide fuel cell (5) are provided with an exhaust gas outlet.

3. The method for operating the solid ammonia SOFC-PEMFC-GT hybrid power generation system according to claim 1, characterized in that: A regenerator (3) is provided between the purifier (2) and the high-temperature proton exchange membrane fuel cell (4); the solid-state ammonia storage-hydrogen production composite module (1), the purifier (2), the regenerator (3) and the anode input end of the high-temperature proton exchange membrane fuel cell (4) are sequentially connected; a pressure reducing valve (15) is provided between the regenerator (3) and the anode input end of the high-temperature proton exchange membrane fuel cell (4); the regenerator (3) is connected to an air inlet; the air inlet, the regenerator (3) and the cathode input end of the high-temperature proton exchange membrane fuel cell (4) are sequentially connected.

4. The method for operating the solid ammonia SOFC-PEMFC-GT hybrid power generation system according to claim 1, characterized in that: The cathode tail gas output end of the high-temperature proton exchange membrane fuel cell (4) is connected to a water vapor separator (7), the hydrogen output end of the water vapor separator (7) and the anode tail gas output end of the high-temperature proton exchange membrane fuel cell (4) are merged into an tail gas flow path, and a one-way control valve (16) is provided on the tail gas flow path.

5. The method for operating the solid ammonia SOFC-PEMFC-GT hybrid power generation system according to claim 1, characterized in that: A second regenerator (6) is provided between the purifier (2) and the solid oxide fuel cell (5); the solid ammonia storage-hydrogen production composite module (1), the purifier (2), the second regenerator (6) and the anode input end of the solid oxide fuel cell (5) are connected in sequence; the cathode input end of the solid oxide fuel cell (5) is connected to the third regenerator (8); the input end of the third regenerator (8) is connected to the compressor (11); and the compressor (11) is connected to an air inlet.

6. The method for operating the solid ammonia SOFC-PEMFC-GT hybrid power generation system according to claim 5, characterized in that: The anode tail gas output end of the solid oxide fuel cell (5) is connected to a water vapor separator (7), the cathode tail gas output end of the solid oxide fuel cell (5) is connected to the regenerator three (8), the hydrogen output end of the water vapor separator (7) and the cathode tail gas output end of the regenerator three (8) are merged into an tail gas flow path, and the tail gas flow path is connected to the regenerator two (6).

7. The method for operating the solid ammonia SOFC-PEMFC-GT hybrid power generation system according to claim 1, characterized in that: The combustion chamber (10) is further provided with an air inlet and a pressure regulating interface, the air inlet is connected to a one-way control valve (16), the pressure regulating interface is connected to a pressure regulator (9), and the pressure regulator (9) is connected to a compressor (11).

8. The method for operating the solid ammonia SOFC-PEMFC-GT hybrid power generation system according to claim 7, characterized in that: The compressor (11) is connected to an electric starter (14), and the compressor (11) is coaxially connected to the turbine (12).

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