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

Abstract

The invention provides a solid-state ammonia SOFC-PEMFC-GT hybrid power generation system and an operation method thereof. The solid-state ammonia SOFC-PEMFC-GT hybrid power generation system comprises a solid-state 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 with a purifier for purifying hydrogen, the purifier is respectively communicated with 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 communicated with the input end of the combustion chamber; the combustion chamber is connected with a turbine which is connected with a generator. In the starting stage, the low-temperature starting of the solid oxide fuel cell is realized; in the stable operation stage, through efficient blending combustion of the combustion chamber, deep chemical heat regeneration is achieved through high-temperature waste gas, the turbine drives the power generator to generate power, and therefore efficient, reliable and green hybrid power generation circulation is achieved.

Description

Technical Field

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

[0002] The 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 change greatly, this method also has certain safety risks, making physical hydrogen storage unfriendly to 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 the European Union, Japan and other countries. According to a report by the International Energy Agency, ammonia fuel is expected to account for 44% of the total fuel in the shipping industry by 2050.

[0003] In terms of hydrogen power generation technology, hydrogen power generation technology can be divided into hydrogen engines and fuel cells using hydrogen as fuel. The ignition energy of hydrogen engines is low, which can easily lead to abnormal combustion phenomena such as backfire and detonation. It is still in the research and development stage. Fuel cells can be divided into solid oxide fuel cells, proton exchange membrane fuel cells, alkaline fuel cells, etc. The first two are currently more mature fuel cells. Solid oxide fuel cells (SOFC) can use its exhaust waste heat as a heat source to decompose ammonia fuel to produce hydrogen, and can further use high-temperature waste heat to couple waste heat power generation and other technologies. It has the advantages of high power generation efficiency, low hydrogen purity requirements, and zero pollution emissions, making SOFC waste heat utilization technology a research hotspot today. For example, patent CN118270212A proposes a ship power system coupled with SOFC-GT and a variable load operation method, which drives the gas turbine through the high-temperature flue gas at the SOFC outlet to improve the overall energy efficiency of the system. For example, patent CN113506902A proposes a hybrid system of solid oxide fuel cells and proton exchange membrane fuel cells using ammonia as fuel, and the unreacted fuel gas at the anode outlet of the solid oxide fuel cell is purified by a separator to form high-purity hydrogen as the fuel of the downstream proton exchange membrane fuel cell, thereby achieving efficient utilization of fuel. Although the patent reuses the hydrogen at the outlet of the solid oxide fuel cell, it ignores that when the system operating conditions change, there will also be unreacted fuel gas at the anode outlet of the proton exchange membrane fuel cell at the tail end. In addition, the patent mainly studies the improvement of fuel utilization. Considering that the tail gas temperature of the solid oxide fuel cell is as high as 600-1000 ℃, and the tail gas temperature of the high-temperature proton exchange membrane fuel cell can be as high as 350 ℃, how to comprehensively utilize the waste heat of the fuel cell tail gas and the unreacted fuel gas needs further study.

[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's power generation cycle. Summary of the invention

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

[0006] A solid ammonia SOFC-PEMFC-GT hybrid power generation system provided by the present invention comprises: 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 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; The output end of the combustion chamber is connected to a turbine, and the turbine is connected to a generator; The exhaust gas output end of the turbine is connected to the solid ammonia storage-hydrogen production composite module and the 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.

[0007] Preferably, a regenerator 1 is arranged 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 arranged 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.

[0008] 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.

[0009] Preferably, a regenerator 2 is provided between the purifier and the solid oxide fuel cell, the solid 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.

[0010] 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.

[0011] Preferably, the combustion chamber is also 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.

[0012] Preferably, the compressor is connected to an electric starter, and the compressor is coaxially connected to the turbine.

[0013] An operating method of a solid ammonia SOFC-PEMFC-GT hybrid power generation system provided by the present invention is applied to the above-mentioned solid ammonia SOFC-PEMFC-GT hybrid power generation system, including a startup operation stage and a stable operation stage.

[0014] Preferably, the startup operation phase includes the following steps: Step 1: After heating, the solid ammonia storage-hydrogen production composite module realizes ammonia desorption and thermal decomposition of ammonia from the solid amino group to obtain a mixed gas; Step 2: After the mixed gas is purified, cooled and depressurized by the purifier, the regenerator 1 and the pressure reducing valve, the hydrogen enters the anode of the high-temperature proton exchange membrane fuel cell. At the same time, the air is heated by the air inlet and the regenerator 1 and enters the cathode of the high-temperature proton exchange membrane fuel cell. The two gases undergo oxidation-reduction reactions at the anode and cathode of the high-temperature proton exchange membrane fuel cell, respectively, to realize the power generation process. Step 3, the anode tail gas of the high temperature proton exchange membrane fuel cell and the cathode tail gas after the water vapor separator are mixed with the retentate gas of the purifier and then flow into the combustion chamber; 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.

[0015] Preferably, the stable operation stage comprises the following steps: Step 1: After heating, the solid ammonia storage-hydrogen production composite module realizes ammonia desorption and thermal decomposition of ammonia from the solid amino group to obtain a mixed gas; Step 2: The mixed gas passes through the purifier and the regenerator 2 and enters the anode of the solid oxide fuel cell as fuel, and the air passes through the compressor and the regenerator 3 to increase the temperature and pressure and then flows into the cathode of the solid oxide fuel cell; 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 burn and generate exhaust gas; In step four, the exhaust gas flows into the turbine to achieve expansion 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 a preset range.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention 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 by providing a combustion chamber, 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 heating 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.

[0017] 2. The present invention can control the combustion temperature in the combustion chamber to meet the operating temperature requirement 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.

[0018] 3. The present invention improves the comprehensive energy efficiency of the system through the efficient coupling of the solid oxide fuel cell, the high-temperature proton exchange membrane fuel cell and the turbine; in the low-temperature start-up stage of the solid oxide fuel cell, the high-temperature proton exchange membrane fuel cell can serve as an auxiliary power generation device and can also provide the required high-temperature waste heat for the low-temperature start-up of the solid oxide fuel cell, thereby effectively improving the energy efficiency of the system in the low-temperature start-up stage; in 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, thereby reducing the power consumption of the compressor, thereby effectively improving the comprehensive energy efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 It is a schematic diagram of a solid ammonia SOFC-PEMFC-GT hybrid power generation system mainly embodied in the present invention.

[0020] As shown in the figure: solid 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

[0021] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments 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 of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0022] 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 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 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 the solid ammonia storage-hydrogen production composite module 1 and the solid oxide fuel cell 5 are both provided with exhaust gas outlets.

[0023] The power generation system of the present application is divided into a startup operation stage and a system stable operation stage.

[0024] During the system startup phase, the solid ammonia storage-hydrogen production composite module 1 is heated to realize the ammonia desorption and thermal decomposition process of the solid amino group, providing fuel for the high-temperature proton exchange membrane fuel cell 4 to realize the power generation process. In addition, after the tail gas of the high-temperature proton exchange membrane fuel cell 4 and part of the retained gas of the purifier 2 flow into the combustion chamber 10 for blending and burning to generate high-temperature low-pressure gas, the flow ratio of the high-temperature gas to the normal temperature air is adjusted in real time to control the temperature of the high-temperature air flowing into the solid oxide fuel cell 5 so that it meets the temperature increase requirement of the solid oxide fuel cell 5 during the low-temperature startup phase.

[0025] In the stable operation stage of the system, the solid ammonia storage-hydrogen production composite module 1 realizes the ammonia desorption and ammonia thermal decomposition process of the solid amino group after heating, and provides fuel for the solid oxide fuel cell 5 to realize the power generation process. At the same time, the high-temperature and high-pressure tail gas of the solid oxide fuel cell 5 flows into the combustion chamber 10 together with part of the retained gas of the purifier 2 to be mixed and burned to generate high-temperature and high-pressure gas, which drives the turbine 12 to expand and do work to drive the generator 13 to generate electricity.

[0026] The solid-state ammonia storage-hydrogen production composite module 1 realizes ammonia desorption and ammonia thermal decomposition process of solid amino groups by being heated, thereby obtaining a high-temperature and high-pressure mixed gas of hydrogen / nitrogen / ammonia to provide fuel for the solid oxide fuel cell 5 and the high-temperature proton exchange membrane fuel cell 4.

[0027] This application can solve the existing problems of insufficient fuel utilization, difficulty in low-temperature start-up of solid oxide fuel cells, and low system energy efficiency. In 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 start-up of the solid oxide fuel cell 5. In 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 the retained gas of part 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.

[0028] 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, so as to prevent other impurities such as ammonia 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, because the fuel cell has a high requirement 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, and 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 realizing efficient use of fuel.

[0029] 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 connected in sequence. 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 connected in sequence. The regenerator-3 is used to cool the high-temperature hydrogen anode gas after passing through the purifier 2 and to heat the inflowing normal-temperature air cathode gas, so that the inflow temperature of the anode gas and the cathode gas matches the high-temperature proton exchange membrane fuel cell 4, thereby improving the operating efficiency of the fuel cell.

[0030] The cathode tail gas output end of the high-temperature proton exchange membrane fuel cell 4 is connected to a 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 tail gas flow path through a three-way valve 17, and a one-way control valve 16 is provided on the tail gas flow path. The tail gas flows into the combustion chamber 10 through valves such as the one-way control valve 16 and the three-way valve 17 in sequence.

[0031] A regenerator 2 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 regenerator 2 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 regenerator 3 8. The input end of the regenerator 3 8 is connected to the compressor 11, and the compressor 11 is connected to the air inlet. The regenerator 2 6 and the regenerator 3 8 are used to heat the high-temperature hydrogen anode gas after passing through the purifier 2 and the normal-temperature air after being pressurized by the compressor 11, respectively, so that the inflow temperature of the anode gas and the cathode gas matches that of the solid oxide fuel cell 5, thereby improving the operating efficiency of the fuel cell.

[0032] 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 then merges at the three-way valve 17, and then flows into the combustion chamber 10.

[0033] 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.

[0034] The combustion chamber 10 includes an exhaust gas inlet, an air inlet, a post-combustion gas outlet, and a pressure regulating interface. The air inlet is connected to a one-way control valve 16, and the flow rate is controlled by the 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. The pressure regulating interface is connected to the pressure regulator 9 through the one-way control valve 16, and the pressure in the combustion chamber 10 is controlled to be consistent with the air pressure after being compressed by the compressor 11, thereby ensuring that the high-temperature and high-pressure exhaust gas of the solid oxide fuel cell 5 can flow into the combustion chamber 10.

[0035] The combustion chamber 10 can effectively control the temperature of the high-temperature tail gas after combustion by controlling the ratio of the inflowing ammonia and hydrogen. This is because the combustion temperature of hydrogen is higher than 1700 ° C, the ignition temperature of ammonia is 653 ° C, the operating temperature of the solid oxide fuel cell is 600-1000 ° C, and the operating temperature of the solid ammonia storage-hydrogen production composite module is 400-700 ° C. In order to meet the temperature requirements of different components, hydrogen and ammonia need to be mixed and burned in a certain proportion. In addition, when the temperature is higher than 800 ° C, the concentration of NOx gas produced by the combustion of ammonia will increase significantly. For this reason, a catalyst can be added to the combustion chamber 10 to reduce the combustion temperature.

[0036] The compressor 11 is connected to an electric starter 14, which is used to drive the compressor 11 to work and compress and increase the pressure of the air when the internal pressure of the solid oxide fuel cell 5 has not yet risen to the stable operating pressure. The compressor 11 is coaxially connected with the turbine 12, and the compressor 11 can drive the turbine 12 to expand and generate electricity through the coaxial drive.

[0037] 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 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, so as to control 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 stage.

[0038] An operating method of a solid ammonia SOFC-PEMFC-GT hybrid power generation system provided by the present invention includes a startup operation stage and a stable operation stage.

[0039] The startup phase includes the following steps: Step 1: After heating, the solid ammonia storage-hydrogen production composite module 1 realizes ammonia desorption and thermal decomposition of ammonia from the solid amino group to obtain a mixed gas; Step 2: After the mixed gas is purified, cooled and depressurized by the purifier 2, the regenerator 3 and the pressure reducing valve 15, the hydrogen enters the anode of the high-temperature proton exchange membrane fuel cell 4. At the same time, the air is heated by the air inlet and the regenerator 3 and enters the cathode of the high-temperature proton exchange membrane fuel cell 4. The two gases undergo oxidation-reduction reactions at the anode and cathode of the high-temperature proton exchange membrane fuel cell 4, respectively, to realize the 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 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.

[0040] When the system is in the startup operation state, the key components of the operation include: solid ammonia storage-hydrogen production composite module 1, high-temperature proton exchange membrane fuel cell 4, solid oxide fuel cell 5. After heating, the solid ammonia storage-hydrogen production composite module 1 realizes the ammonia desorption and ammonia thermal decomposition process of the solid amino group, thereby obtaining a high-temperature and high-pressure mixed gas of hydrogen / nitrogen / ammonia. The high-temperature and high-pressure mixed gas is purified, cooled and depressurized by the purifier 2, the regenerator-3, and the pressure reducing valve 15, and then enters the anode of the high-temperature proton exchange membrane fuel cell 4. At the same time, the air is heated through the air inlet and the regenerator-3, and then enters the cathode of the high-temperature proton exchange membrane fuel cell 4. Then the two gases undergo oxidation-reduction reactions at the anode and cathode of the fuel cell respectively to realize the power generation process. Then the anode tail gas of the high-temperature proton exchange membrane fuel cell 4 and the cathode tail gas passing through the water vapor separator 7 are merged into one flow path after the three-way valve 17, and successively pass through the one-way control valve 16, the three-way valve 17 and other valves, and mix with the stagnant gas of the purifier 2 and flow 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 at a certain proportion at the three-way valve 17, and then enters the solid oxide fuel cell 5 for preheating. This is because the rapid temperature rise will cause a temperature gradient in the material inside the solid oxide fuel cell, which will in turn induce thermal stress, which is easy to 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.

[0041] The stable operation phase includes the following steps: Step 1: After heating, the solid ammonia storage-hydrogen production composite module 1 realizes ammonia desorption and thermal decomposition of ammonia from the solid amino group to obtain a mixed gas; 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, and the air passes through the compressor 11 and the regenerator 3 8 to increase temperature and pressure and then flows 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; 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.

[0042] In the stable operation stage of the system, the key components include a solid ammonia storage-hydrogen production composite module 1, a solid oxide fuel cell 5 and a turbine 12. The high-temperature and high-pressure mixed gas flowing out of the solid ammonia storage-hydrogen production composite module 1 enters the anode of the solid oxide fuel cell 5 through the purifier 2 and the regenerator 2 6 to provide fuel; the air flows into the cathode of the solid oxide fuel cell 5 after being heated and pressurized by the compressor 11, the three-way valve 17 and the regenerator 3 8. After the cathode outflow gas of the solid oxide fuel cell is reheated with the inlet air through the regenerator 3 8, it is mixed with the gas at the cathode outlet through the three-way valve 17, flows into the regenerator 2 6, and reheats with the fuel at the cathode inlet. After deep reheating, the outlet exhaust gas of the solid oxide fuel cell 5 is further mixed with part of the ammonia gas retained at the outlet of the purifier 2 through the three-way valve 17, and flows into the combustion chamber 10 to burn and generate higher temperature and high pressure exhaust gas. The exhaust gas can directly flow into the turbine 12 to achieve expansion work without the auxiliary pressurization of the electric starter 14, 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 is stable within a certain range when the operating parameters change.

[0043] The present application can effectively improve the fuel utilization rate of the system. 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 by providing a combustion chamber 10, 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 of 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 by providing a water vapor separator 7 to prevent water vapor from flowing into the combustion chamber 10, the fuel utilization rate of the system is effectively improved, and the chemical energy in the fuel is released to the maximum extent.

[0044] The present application can achieve efficient matching of the temperature required for low-temperature startup of the solid oxide fuel cell 5. The present application can control the combustion temperature in the combustion chamber 10 to meet the operating temperature requirement of 600-1000°C of the solid oxide fuel cell 5 by adjusting the flow rate of ammonia and hydrogen flowing into the combustion chamber 10. 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 heating requirement of the solid oxide fuel cell 5 in the low-temperature startup stage, and achieve efficient matching of the temperature required for low-temperature startup of the solid oxide fuel cell 5.

[0045] The present application can realize the efficient coupling of the solid oxide fuel cell 5, the high temperature proton exchange membrane fuel cell 4 and the turbine 12, and improve the comprehensive energy utilization efficiency of the system. In the low temperature start-up stage 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 required high temperature waste heat for the low temperature start-up of the solid oxide fuel cell 5, thereby effectively improving the energy utilization efficiency of the system in the low temperature start-up stage. In the stable operation stage 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 using 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 comprehensive energy utilization efficiency of the system.

[0046] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0047] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A solid ammonia SOFC-PEMFC-GT hybrid power generation system, characterized in that: include: A solid-state 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-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 retentate 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 discharge outlet.

2. The solid ammonia SOFC-PEMFC-GT hybrid power generation system according to claim 1, characterized in that: A regenerator one (3) is arranged 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 one (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 arranged between the regenerator one (3) and the anode input end of the high-temperature proton exchange membrane fuel cell (4); the regenerator one (3) is connected to an air inlet; the air inlet, the regenerator one (3) and the cathode input end of the high-temperature proton exchange membrane fuel cell (4) are sequentially connected.

3. 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.

4. 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 a third regenerator (8); the input end of the third regenerator (8) is connected to a compressor (11); and the compressor (11) is connected to an air inlet.

5. The solid ammonia SOFC-PEMFC-GT hybrid power generation system according to claim 4, 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 in communication with a third regenerator (8), the hydrogen output end of the water vapor separator (7) and the cathode tail gas output end of the third regenerator (8) are merged into an tail gas flow path, and the tail gas flow path is in communication with a second regenerator (6).

6. The solid ammonia SOFC-PEMFC-GT hybrid power generation system according to claim 1, characterized in that: The combustion chamber (10) is also 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).

7. The solid ammonia SOFC-PEMFC-GT hybrid power generation system according to claim 6, characterized in that: The compressor (11) is connected to an electric starter (14), and the compressor (11) is coaxially connected to a turbine (12).

8. A method for operating a solid ammonia SOFC-PEMFC-GT hybrid power generation system, characterized in that: The solid ammonia SOFC-PEMFC-GT hybrid power generation system applied to any one of claims 1 to 7 comprises a startup operation phase and a stable operation phase.

9. The operating method of the solid ammonia SOFC-PEMFC-GT hybrid power generation system according to claim 8, characterized in that: The startup operation phase includes the following steps: Step 1: After heating, the solid ammonia storage-hydrogen production composite module (1) is subjected to ammonia desorption and thermal decomposition of the solid amino group to obtain a mixed gas; Step 2: After the mixed gas is purified, cooled and depressurized by passing through the purifier (2), the regenerator (3) and the pressure reducing valve (15), the hydrogen enters the anode of the high-temperature proton exchange membrane fuel cell (4). At the same time, the air is heated by passing through the air inlet and the regenerator (3) and enters the cathode of the high-temperature proton exchange membrane fuel cell (4). The two gases undergo oxidation-reduction reactions at the anode and cathode of the high-temperature proton exchange membrane fuel cell (4) respectively, thereby realizing the 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); 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.

10. The operating method of the solid ammonia SOFC-PEMFC-GT hybrid power generation system according to claim 9, characterized in that: The stable operation stage includes the following steps: Step 1: After heating, the solid ammonia storage-hydrogen production composite module (1) is subjected to 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 second 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 third regenerator (8) to increase the temperature and pressure and then flows 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 reheater 3 (8), and then flows into the reheater 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, thereby 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.

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