A natural gas-diesel dual fuel solid oxide fuel cell power generation system

Abstract

The application discloses a natural gas and kerosene dual-fuel solid oxide fuel cell power generation system, which comprises a material supply unit, a fuel reforming unit, a heat management unit and a stack; the material supply unit comprises a kerosene supply assembly, a natural gas supply assembly, an air supply assembly and a water vapor supply assembly; the fuel reforming unit comprises an oil-gas-water mixing tank, a first-stage reformer and a second-stage reformer which are sequentially connected; the oil-gas-water mixing tank is connected with the kerosene supply assembly, the natural gas supply assembly and the water vapor supply assembly respectively; the heat management unit comprises a combustor and a reformer heat exchanger; the combustor is connected with the reformer heat exchanger; the reformer heat exchanger is connected with the second-stage reformer; the inlet of the stack is connected with the reformer heat exchanger and the air supply assembly respectively; and the outlet of the stack is connected with the combustor. In the application, natural gas and kerosene can be used as fuel, the fuel can be switched flexibly according to the scene, and the application scene of the fuel cell is expanded.

Description

Technical Field

[0001] This invention relates to the field of fuel cell power generation technology, and more particularly to a dual-fuel solid oxide fuel cell power generation system for natural gas and kerosene. Background Technology

[0002] Solid oxide fuel cells (SOFCs) operate at temperatures of 600–800℃, classifying them as medium- to high-temperature fuel cells. They offer advantages such as fast electrochemical reaction rates, low ohmic losses, and high efficiency. Furthermore, their electrode materials exhibit strong resistance to carbon monoxide, significantly enhancing their adaptability to various fuels. Besides hydrogen, they can also utilize conventional hydrocarbon fuels such as natural gas, biogas, methanol, diesel, and ammonia for power generation.

[0003] Currently, the main fuel for SOFC power generation systems is natural gas. A mixture of H2, CO, CO2, CH4, and H2O, produced after partial pre-reforming of the natural gas, is heated before entering the fuel cell stack for power generation. The stack structure, especially the flow channel structure, is specifically designed based on the flow rate and composition of the inlet gas, as well as the stack's own power generation characteristics, to achieve a small stack temperature difference and low pressure loss, thereby reducing thermal stress and gas leakage, and ultimately improving stack performance and lifespan. However, since currently developed stacks are primarily designed for natural gas, they typically require natural gas as fuel, resulting in relatively poor compatibility with other fuels. Besides the stack structure needing to adapt to the flow rate, composition, and calorific value of other fuels, the properties of the catalyst in the reformer also make it difficult to meet the pre-reforming requirements of different fuels.

[0004] Kerosene and diesel fuels possess advantages such as low flash point, low pour point, high calorific value, and convenient storage and use, making them highly suitable as fuels for power generation systems in ships and isolated islands. While SOFCs offer good fuel adaptability, achieving efficient and reliable power generation requires customized redesign of the system and even the fuel cell stack. For example, the burner must adapt to changes in fuel liquid-gas morphology under different operating conditions, the heat exchanger must consider kerosene evaporators and superheaters, the reformer must have a redesigned catalyst, and even the fuel cell stack needs adaptive improvements to flow channels and the design of anti-carbon deposition materials. Developing kerosene SOFC power generation systems is extremely costly.

[0005] Therefore, it is necessary to design an improved natural gas-kerosene dual-fuel solid oxide fuel cell power generation system based on a conventional natural gas SOFC power generation system to solve the above problems. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention aims to provide a dual-fuel solid oxide fuel cell power generation system that can use both natural gas and kerosene as fuels, and can flexibly switch fuels according to the scenario, thus expanding the application scenarios of fuel cells.

[0007] To achieve the above objectives, the present invention provides a dual-fuel solid oxide fuel cell power generation system for natural gas and kerosene, comprising:

[0008] The material supply unit includes a kerosene supply component, a natural gas supply component, an air supply component, and a steam supply component;

[0009] The fuel reforming unit includes an oil-gas-water mixing tank, a first-stage reformer, and a second-stage reformer connected in sequence. The oil-gas-water mixing tank is connected to the kerosene supply assembly, the natural gas supply assembly, and the steam supply assembly, respectively. The first-stage reformer is used to convert kerosene into methane-rich gas, and the second-stage reformer is used to convert the methane-rich gas into hydrogen-rich gas.

[0010] A thermal management unit, comprising a burner and a reformer heat exchanger, wherein the burner is connected to the reformer heat exchanger and the reformer heat exchanger is connected to the second-stage reformer.

[0011] The fuel cell stack has its anode gas inlet connected to the reformer heat exchanger, its cathode gas inlet connected to the air supply assembly, its anode exhaust gas outlet connected to the anode exhaust gas inlet of the burner, and its cathode exhaust gas outlet connected to the cathode exhaust gas inlet of the burner.

[0012] In some embodiments, the thermal management unit further includes a kerosene preheater, a start-up evaporator, a steam superheater, a steam cooler, an air heat exchanger, a water evaporator, and a waste heat recovery unit. The kerosene supply assembly is connected to the oil-gas-water mixing tank via the kerosene preheater. The air supply assembly is connected to the cathode gas inlet of the fuel cell stack via the air heat exchanger. The steam supply assembly is connected to the oil-gas-water mixing tank in sequence via the start-up evaporator, the water evaporator, the steam superheater, and the steam cooler.

[0013] The flue gas outlet of the burner is sequentially welded to the reformer heat exchanger, the steam superheater, the air heat exchanger, the water evaporator, and the waste heat recovery unit via pipelines, so that the flue gas discharged from the burner passes through the hot side flow channel of the above components and is finally discharged through the outlet of the waste heat recovery unit.

[0014] In some embodiments, the kerosene supply assembly includes a kerosene storage tank and an oil pump. The kerosene storage tank is connected to the kerosene preheater via the oil pump. The kerosene pumped out by the oil pump is processed into kerosene vapor by the kerosene preheater and then input into the oil-gas-water mixing tank.

[0015] In some embodiments, the natural gas supply assembly includes a natural gas transmission device, a desulfurization device, and a flow controller. One end of the desulfurization device is connected to the natural gas transmission device, and the other end of the desulfurization device is connected in sequence to the flow controller and the oil-gas-water mixing tank through pipelines and connectors to input natural gas into the oil-gas-water mixing tank.

[0016] In some embodiments, the air supply assembly includes a fan and a flow meter, the outlet of the fan being connected to the flow meter, and the flow meter being connected to the inlet of the air heat exchanger via pipes and connectors to input air at a preset temperature into the fuel cell stack.

[0017] In some embodiments, the air heat exchanger is provided with an air bypass valve connected in parallel. The inlet end of the air bypass valve is connected to the inlet end of the air heat exchanger, and the outlet end of the air bypass valve is connected to the outlet end of the air heat exchanger. Adjusting the opening degree of the air bypass valve can adjust a portion of the cold air to be directly mixed with the high-temperature air heated by the air heat exchanger at the outlet of the air heat exchanger, thereby playing a temperature regulation role.

[0018] In some embodiments, the steam supply assembly includes a deionized water tank and a metering water pump. One end of the metering water pump is connected to the deionized water tank, and the other end of the metering water pump is connected to the starting evaporator. The starting evaporator, the water evaporator, the steam superheater, the steam cooler, and the oil-gas-water mixing tank are connected in sequence through pipelines and connectors to input steam at a preset temperature into the oil-gas-water mixing tank.

[0019] In some embodiments, the steam cooler is a gas-to-gas heat exchanger, wherein the hot side is water vapor and the cold side is room temperature air, and the water vapor temperature is adjusted by regulating the amount of room temperature air blown in.

[0020] In some embodiments, the waste heat recovery unit is connected to a water pump that connects room temperature water to the waste heat recovery unit via pipes and connectors to generate hot water from the room temperature water.

[0021] In some embodiments, the reformer is equipped with an electric heating component, which can realize the kerosene pre-conversion function to convert kerosene into C1 components with a conversion rate of over 99.98%, a reaction temperature of 450-500°C, and an outlet product of methane-rich gas.

[0022] The two-stage reformer is equipped with an electric heating component, which can realize partial methane reforming to produce hydrogen. The reaction temperature is 500-700℃, and the outlet product is hydrogen-rich gas. The C2 and above components in the component at the outlet of the two-stage reformer are lower than the stack tolerance value.

[0023] Compared with the prior art, the natural gas-kerosene dual-fuel solid oxide fuel cell power generation system provided by the present invention has at least one of the following beneficial effects:

[0024] 1. The natural gas and kerosene dual-fuel solid oxide fuel cell power generation system provided by the present invention can realize the dual-fuel operation of natural gas and diesel. It adopts a two-stage reforming reaction. The first-stage reformer realizes the kerosene pre-conversion function, eliminating C2 and above components of kerosene, while having little impact on natural gas. The second-stage reformer realizes the partial methane reforming hydrogen production function, which is effective for both kerosene pre-conversion products and natural gas, and generates anode gas suitable for the operation of the fuel cell stack.

[0025] 2. The natural gas and kerosene dual-fuel solid oxide fuel cell power generation system provided by the present invention can be simply improved on the basis of the original natural gas SOFC system without redesigning the stack or even the system framework. It only requires the addition of a kerosene storage tank, oil pump, kerosene preheater, oil-gas-water mixing tank, and improvements to the reformer, as well as the addition of a kerosene pre-conversion functional section, to achieve dual-fuel power generation. Its modification cost is low.

[0026] 3. The natural gas and kerosene dual-fuel solid oxide fuel cell power generation system provided by the present invention fully recovers the thermal and chemical energy of the flue gas at the stack outlet through thermal management, and transfers the heat to the material entering the system through a heat exchanger; it uses components such as air bypass valve, steam cooler, and reformer electric heating component to regulate the gas composition and temperature at the stack inlet, ensuring that the stack and system operate in a reliable and high-efficiency environment. Attached Figure Description

[0027] The preferred embodiments will now be described in a clear and easy-to-understand manner, in conjunction with the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages, and implementation methods of the present invention.

[0028] Figure 1 This is a schematic diagram of the structure of a preferred embodiment of the natural gas-kerosene dual-fuel solid oxide fuel cell power generation system of the present invention.

[0029] Explanation of icon numbers:

[0030] 1. Kerosene storage tank; 2. Oil pump; 3. Natural gas transmission device; 4. Desulfurization device; 5. Flow controller; 6. Fan; 7. Flow meter; 8. Air bypass valve; 9. Room temperature water; 10. Water pump; 11. Hot water; 12. Deionized water tank; 13. Metering water pump; 14. Oil-gas-water mixing tank; 15. First-stage reformer; 16. Second-stage reformer; 17. Burner; 18. Reformer heat exchanger; 19. Steam superheater; 20. Air heat exchanger; 21. Water evaporator; 22. Waste heat recovery unit; 23. Start-up evaporator; 24. Steam cooler; 25. Kerosene preheater; 26. Electric stack; 27. Flue gas; 28. Air. Detailed Implementation

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0032] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and these do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0033] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0034] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] In one embodiment, refer to the appendix to the specification. Figure 1The present invention provides a dual-fuel solid oxide fuel cell power generation system consisting of a natural gas and kerosene, comprising: a material supply unit, a fuel reforming unit, a thermal management unit, and a fuel cell stack 26. The material supply unit includes a kerosene supply assembly, a natural gas supply assembly, an air supply assembly, and a steam supply assembly. The material reforming unit includes an oil-gas-water mixing tank 14, a first-stage reformer 15, and a second-stage reformer 16 connected in sequence. The oil-gas-water mixing tank 14 is connected to the kerosene supply assembly, the natural gas supply assembly, and the steam supply assembly, respectively. The first-stage reformer 15 converts kerosene into methane-rich gas, and the second-stage reformer 16 converts methane-rich gas into hydrogen-rich gas. The thermal management unit includes a burner 17 and a reformer heat exchanger 18. The burner 17 is connected to the reformer heat exchanger 18, and the reformer heat exchanger 18 is connected to the second-stage reformer 16. The anode gas inlet of the fuel cell stack 26 is connected to the reformer heat exchanger 18, the cathode gas inlet of the fuel cell stack 26 is connected to the air supply assembly, the anode exhaust gas outlet of the fuel cell stack 26 is connected to the anode exhaust gas inlet of the burner 17, and the cathode exhaust gas outlet of the fuel cell stack 26 is connected to the cathode exhaust gas inlet of the burner 17.

[0037] The thermal management unit also includes a kerosene preheater 25, a start-up evaporator 23, a steam superheater 19, a steam cooler 24, an air heat exchanger 20, a water evaporator 21, and a waste heat recovery unit 22. The kerosene supply assembly is connected to the oil-gas-water mixing tank 14 via the kerosene preheater 25. The air supply assembly is connected to the cathode gas inlet of the fuel cell stack 26 via the air heat exchanger 20. The steam supply assembly is connected to the oil-gas-water mixing tank 14 in sequence via the start-up evaporator 23, the water evaporator 21, the steam superheater 19, and the steam cooler 24. The flue gas outlet of the burner 17 is connected to the reformer heat exchanger 18, the steam superheater 19, the air heat exchanger 20, the water evaporator 21, and the waste heat recovery unit 22 via pipe welding, so that the flue gas 27 discharged from the burner 17 passes through the hot-side flow channels of the above components and is finally discharged through the outlet of the waste heat recovery unit 22.

[0038] Specifically, the kerosene supply assembly is used to supply kerosene. It includes a kerosene storage tank 1 and an oil pump 2. The kerosene storage tank 1 is connected to the kerosene preheater 25 via the oil pump 2. The kerosene pumped by the oil pump 2 is prepared into kerosene vapor at a preset temperature by the kerosene preheater 25 and then input into the oil-gas-water mixing tank 14.

[0039] The natural gas supply assembly is used to supply natural gas and includes a natural gas transmission device 3, a desulfurization device 4, and a flow controller 5. One end of the desulfurization device 4 is connected to the natural gas transmission device 3, which can be a natural gas supply pipeline or a natural gas storage tank, etc. The other end of the desulfurization device 4 is connected in sequence to the flow controller 5 and the oil-gas-water mixing tank 14 through pipelines and connectors to input natural gas into the oil-gas-water mixing tank 14.

[0040] The air supply assembly includes a fan 6 and a flow meter 7. The outlet of the fan 6 is connected to the flow meter 7, and the flow meter 7 is connected to the inlet of the air heat exchanger 20 via pipes and connectors to heat the air 28 to a preset temperature before feeding it into the fuel cell stack 26. There is a bypass between the flow meter 7 and the outlet of the air heat exchanger 20. An air bypass valve 8 is installed in the middle of this bypass. Adjusting the opening of the air bypass valve 8 can adjust the temperature so that some cold air is directly mixed with the high-temperature air heated by the air heat exchanger 20 at the outlet of the air heat exchanger 20, thereby regulating the temperature.

[0041] The steam supply assembly includes a deionized water tank 12 and a metering water pump 13. One end of the metering water pump 13 is connected to the deionized water tank 12, and the other end is connected to the start-up evaporator 23. The start-up evaporator 23, water evaporator 21, steam superheater 19, steam cooler 24, and oil-gas-water mixing tank 14 are connected sequentially through pipes and connectors to input steam at a preset temperature into the oil-gas-water mixing tank 14. The steam cooler 24 is a gas-to-gas heat exchanger, where the hot side is steam and the cold side is room temperature air. The steam temperature is adjusted by regulating the amount of room temperature air blown in.

[0042] Waste heat recovery unit 22 is connected to water pump 10. Water pump 10 connects room temperature water 9 to waste heat recovery unit 22 through pipes and connectors to generate hot water 11 from room temperature water 9.

[0043] The oil-gas-water mixing tank 14 has three inlets and one outlet. The three inlets are connected to the kerosene preheater 25 for kerosene, the steam cooler 24 for steam, and the flow controller 5 for natural gas, respectively. The outlet is connected to a first-stage reformer. The outlet of the oil-gas-water mixing tank 14 is sequentially connected to the first-stage reformer 15, the second-stage reformer 16, and the reformer heat exchanger 18. During the start-up phase and in natural gas mode, the internal mixing fluid of the oil-gas-water mixing tank 14 is room temperature natural gas and high-temperature steam. In kerosene mode, the internal mixing fluid is kerosene vapor preheated by kerosene and high-temperature steam. During the natural gas and kerosene switching process, the internal mixing fluid is kerosene vapor, natural gas, and high-temperature steam.

[0044] The first-stage reformer 15 performs kerosene pre-conversion, converting kerosene into C1 components with a conversion rate exceeding 99.98%. The reaction temperature is 450–500℃, and the outlet product is methane-rich gas. The second-stage reformer 16 performs partial methane reforming for hydrogen production, with a reaction temperature of 500–700℃, and the outlet product is hydrogen-rich gas. The kerosene preheater 25 and high-temperature steam provide the temperature conditions for the reforming reactions in the first-stage and second-stage reformers 15 and 16. In addition, both the first-stage and second-stage reformers 15 are equipped with electric heating components to ensure that from start-up to power generation, the C2 and higher components in the outlet of the second-stage reformer 16 are below the stack's tolerance level.

[0045] A dual-fuel solid oxide fuel cell power generation system for natural gas and kerosene, the specific operation process of which is as follows:

[0046] During startup, natural gas is used for startup. Natural gas passes through desulfurization device 4, flow controller 5, oil-gas-water mixing tank 14, first-stage reformer 15, second-stage reformer 16, reformer heat exchanger 18, and fuel cell stack 26, and enters the anode tail gas inlet of burner 17. It then undergoes a combustion reaction with the air that passes through fan 6, flow meter 7, air heat exchanger 20, and fuel cell stack 26, and enters the cathode tail gas inlet of burner 17, thus heating the system.

[0047] When the inlet air temperature of the fuel cell stack 26 reaches a certain value, such as 250℃, 280℃, 300℃, 320℃, or 350℃, the system enters the water reforming stage. The metering water pump 13 and the start-up evaporator 23 begin to work, introducing deionized water into the system. The deionized water passes through the metering water pump 13, the start-up evaporator 23, the water evaporator 21, the steam superheater 19, and the steam cooler 24 before entering the oil-gas-water mixing tank 14 to mix with natural gas. After passing through the first-stage reformer 15, the reforming reaction begins in the second-stage reformer 16. When the flue gas inlet temperature of the waste heat recovery unit 22 exceeds a certain value, such as 200℃, 210℃, 220℃, 230℃, 240℃, or 250℃, the start-up evaporator 23 can be shut down.

[0048] When the inlet air temperature of fuel cell stack 26 reaches a certain value, such as 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, or 800℃, fuel cell stack 26 enters the hot standby stage. During this stage, fuel switching can be selected. If natural gas is used for power generation, natural gas continues to be supplied while slowly discharging until a stable power generation state is reached. If kerosene is used for power generation, natural gas is slowly switched to kerosene. During the switching process, the calorific value and water-to-carbon ratio of the fuel are kept constant, and the amount switched each time does not exceed 2%, with a switching interval of more than 2 minutes. At the same time, the temperature measuring points of the first-stage reformer 15 and the second-stage reformer 16 are monitored. If the reformer temperature is detected to be lower than the minimum reforming temperature, the electric heater is turned on.

[0049] The minimum reforming temperature is determined by reforming tests. The reformer outlet composition corresponding to different reformer temperatures, different kerosene flow rates and water-carbon ratios is obtained through tests. The reformer temperature corresponding to 100 ppm of C2 and above components is determined as the minimum reformer temperature.

[0050] In one specific embodiment, taking a 15kW power generation output system as an example, during startup, fan 6 is turned on, and the flow rate of fan 6 is controlled by flow meter 7 to reach a specified value of ~1200SLM (standard liters / minute). A small flow of natural gas is introduced through flow controller 5, and burner 17 is ignited and started, slowly heating up the system. The high-temperature flue gas generated by combustion sequentially enters reformer heat exchanger 18 through burner 17 outlet to preheat fuel gas, enters steam superheater 19 to heat steam, enters air heat exchanger 20 to heat air, enters water evaporator 21 to heat evaporated water, and enters waste heat recovery unit 22 to heat room temperature water. The heated cathode and anode gases from the outlet of air heat exchanger 20 and reformer heat exchanger 18 enter fuel cell stack 26 to heat fuel cell stack 26.

[0051] When the cathode air temperature at the inlet of fuel cell stack 26 reaches ~300℃, the water reforming stage begins. The evaporator 23 is started for preheating for 5 minutes, and the metering water pump 13 is started, using a water-to-carbon molar ratio of 2 (e.g., kerosene C). 12 H 26 If the concentration of H2 is 1 mol, then the concentration of water is 24 mol. Water is introduced, and at this time, natural gas and water vapor mix in the oil-gas-water mixing tank 14, then enter the first-stage reformer 15 and the second-stage reformer 16. The reforming reaction of natural gas and water vapor to produce hydrogen mainly occurs in the second-stage reformer 16. As the system temperature increases, the degree of reforming reaction between natural gas and water tends to increase, and the proportion of H2 in the anode gas entering the fuel cell stack 26 will also increase accordingly.

[0052] When the cathode air temperature at the inlet of fuel cell stack 26 reaches ~650℃, the system enters the hot standby stage. At this time, different fuels can be selected as power generation feedstocks. If natural gas is used as fuel, the system gradually discharges while increasing the amount of natural gas until the system reaches equilibrium and the fuel cell stack operates under reliable and high-efficiency conditions, achieving stable power generation. If kerosene is used as fuel, fuel switching can be performed during the hot standby stage, i.e., slowly switching from natural gas to kerosene. During the switching process, the calorific value and water-to-carbon ratio of the fuel remain unchanged, and the amount of switching each time does not exceed 2%, with a switching interval of more than 2 minutes. At the same time, the temperature measuring points of the first-stage reformer 15 and the second-stage reformer 16 are monitored. If the reformer temperature is found to be lower than the minimum reforming temperature, the electric heater is turned on. The example shows that the minimum temperature of the first-stage reformer is ~570℃ and the minimum temperature of the second-stage reformer is ~510℃.

[0053] Table 1 shows the calculated parameters of the anode gas outlet, outlet composition, and parameters of the fuel cell stack when generating a stable 15kW power in both natural gas and kerosene power modes. All parameters are within the range where the fuel cell stack can operate well, indicating the feasibility of the proposed system to some extent.

[0054] Table 1. Inlet and outlet parameters of fuel cell stacks for natural gas and kerosene power generation.

[0055]

[0056] In this embodiment, the natural gas-kerosene dual-fuel solid oxide fuel cell power generation system can achieve dual-fuel operation of natural gas and diesel. It employs a two-stage reforming reaction. The first-stage reformer 15 performs kerosene pre-conversion, eliminating C2 and higher components from the kerosene while having minimal impact on natural gas. The second-stage reformer 16 performs partial methane reforming for hydrogen production, effectively processing both kerosene pre-conversion products and natural gas, and generating anode gas suitable for the stack's operation. The system can be implemented with simple modifications to an existing natural gas SOFC system, without requiring a redesign of the stack or even the entire system framework. It only requires adding a kerosene storage tank 1, an oil pump 2, a kerosene preheater 25, an oil-gas-water mixing tank 14, and an improved reformer to add a kerosene pre-conversion function stage. Thermal management fully recovers the thermal and chemical energy of the stack outlet flue gas, transferring heat to the incoming materials via a heat exchanger. Air bypass valve 8, steam cooler 24, and reformer electric heating components regulate the gas composition and temperature at the stack inlet, ensuring reliable and high-efficiency operation of the stack and system.

[0057] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0058] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dual-fuel solid oxide fuel cell power generation system for natural gas and kerosene, characterized in that, include: The material supply unit includes a kerosene supply component, a natural gas supply component, an air supply component, and a steam supply component; The fuel reforming unit includes an oil-gas-water mixing tank, a first-stage reformer, and a second-stage reformer connected in sequence. The oil-gas-water mixing tank is connected to the kerosene supply assembly, the natural gas supply assembly, and the steam supply assembly, respectively. The first-stage reformer is used to eliminate C2 and higher components of kerosene and convert it into methane-rich gas. The second-stage reformer is used to convert the methane-rich gas into hydrogen-rich gas. The C2 and higher components in the composition at the outlet of the second-stage reformer are lower than the stack tolerance value. A thermal management unit, comprising a burner and a reformer heat exchanger, wherein the burner is connected to the reformer heat exchanger and the reformer heat exchanger is connected to the second-stage reformer. The fuel cell stack has its anode gas inlet connected to the reformer heat exchanger, its cathode gas inlet connected to the air supply assembly, its anode exhaust gas outlet connected to the anode exhaust gas inlet of the burner, and its cathode exhaust gas outlet connected to the cathode exhaust gas inlet of the burner. The reformer is equipped with an electric heating component, which can realize the kerosene pre-conversion function to convert kerosene into C1 components with a conversion rate of over 99.98%, a reaction temperature of 450~500℃, and an outlet product of methane-rich gas. The two-stage reformer is equipped with an electric heating component, which can realize partial methane reforming to produce hydrogen. The reaction temperature is 500~700℃, and the outlet product is hydrogen-rich gas.

2. The natural gas / kerosene dual-fuel solid oxide fuel cell power generation system according to claim 1, characterized in that, The thermal management unit further includes a kerosene preheater, a start-up evaporator, a steam superheater, a steam cooler, an air heat exchanger, a water evaporator, and a waste heat recovery unit. The kerosene supply assembly is connected to the oil-gas-water mixing tank through the kerosene preheater. The air supply assembly is connected to the cathode gas inlet of the fuel cell stack through the air heat exchanger. The steam supply assembly is connected to the oil-gas-water mixing tank in sequence through the start-up evaporator, the water evaporator, the steam superheater, and the steam cooler. The flue gas outlet of the burner is sequentially welded to the reformer heat exchanger, the steam superheater, the air heat exchanger, the water evaporator, and the waste heat recovery unit via pipelines, so that the flue gas discharged from the burner passes through the hot side channels of the reformer heat exchanger, the steam superheater, the air heat exchanger, and the water evaporator, and finally exits through the outlet of the waste heat recovery unit.

3. The natural gas / kerosene dual-fuel solid oxide fuel cell power generation system according to claim 2, characterized in that, The kerosene supply assembly includes a kerosene storage tank and an oil pump. The kerosene storage tank is connected to the kerosene preheater via the oil pump. The kerosene pumped out by the oil pump is processed into kerosene vapor by the kerosene preheater and then input into the oil-gas-water mixing tank.

4. The natural gas / kerosene dual-fuel solid oxide fuel cell power generation system according to claim 2, characterized in that, The natural gas supply assembly includes a natural gas transmission device, a desulfurization device, and a flow controller. One end of the desulfurization device is connected to the natural gas transmission device, and the other end of the desulfurization device is connected in sequence to the flow controller and the oil-gas-water mixing tank through pipelines and connectors to input natural gas into the oil-gas-water mixing tank.

5. The natural gas / kerosene dual-fuel solid oxide fuel cell power generation system according to claim 2, characterized in that, The air supply assembly includes a fan and a flow meter. The outlet of the fan is connected to the flow meter, and the flow meter is connected to the inlet of the air heat exchanger through pipes and connectors to input air at a preset temperature into the fuel cell stack.

6. The natural gas / kerosene dual-fuel solid oxide fuel cell power generation system according to claim 5, characterized in that, The air heat exchanger is equipped with air bypass valves connected in parallel. The inlet end of the air bypass valve is connected to the inlet end of the air heat exchanger, and the outlet end of the air bypass valve is connected to the outlet end of the air heat exchanger. Adjusting the opening degree of the air bypass valve can adjust the amount of cold air to be directly mixed with the high-temperature air heated by the air heat exchanger at the outlet of the air heat exchanger, thereby playing a role in temperature regulation.

7. The natural gas / kerosene dual-fuel solid oxide fuel cell power generation system according to claim 2, characterized in that, The steam supply assembly includes a deionized water tank and a metering water pump. One end of the metering water pump is connected to the deionized water tank, and the other end of the metering water pump is connected to the starting evaporator. The starting evaporator, the water evaporator, the steam superheater, the steam cooler, and the oil-gas-water mixing tank are connected in sequence through pipelines and joints to input steam at a preset temperature into the oil-gas-water mixing tank.

8. The natural gas / kerosene dual-fuel solid oxide fuel cell power generation system according to claim 7, characterized in that, The steam cooler is a gas-to-gas heat exchanger, in which the hot side is water vapor and the cold side is room temperature air. The temperature of the water vapor is adjusted by regulating the amount of room temperature air blown in.

9. The natural gas / kerosene dual-fuel solid oxide fuel cell power generation system according to claim 2, characterized in that, The waste heat recovery unit is connected to a water pump, which connects room temperature water to the waste heat recovery unit through pipes and connectors to generate hot water from the room temperature water.

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