Multi-stage humidity regulation and control fuel cell gas turbine hybrid power generation system

Abstract

The invention provides a fuel cell and gas turbine hybrid power generation system with a multi-stage humidity regulation and control function, and belongs to the technical field of distributed energy. The system comprises a multi-stage humidity regulation and control module, and the fuel humidity is regulated stage by stage to ensure continuous optimization of the fuel water-carbon ratio, so that local carbon deposition of an SOFC anode is avoided; the pre-reforming module is used for preliminarily cracking the multi-carbon hydrocarbon fuel and avoiding the problem of electrode blockage caused by deposition of complex carbon chain substances in an SOFC anode chamber; the internal reforming solid oxide fuel cell module is connected with the pre-reforming module and is used for generating power by using fuel, and the fuel inclusion degree and the energy utilization rate of the internal reforming solid oxide fuel cell module are higher than those of a traditional solid oxide fuel cell; and the gas turbine module adopts a low-pressure integrated gas turbine and utilizes high-temperature tail gas discharged by a battery anode to generate power, so that secondary utilization of energy is realized. Through multi-stage humidity regulation and control, pre-reforming and heat energy gradient utilization, the efficiency of the hybrid power generation system is improved, the service life of the SOFC is effectively prolonged, and high efficiency and practicability are achieved.

Description

Technical Field

[0001] This invention belongs to the field of distributed energy technology, specifically relating to a fuel cell gas turbine hybrid power generation system with multi-level humidity control. Background Technology

[0002] Faced with the increasingly severe energy crisis and environmental challenges, developing efficient, clean, and low-carbon power generation technologies has become a global consensus, and countries around the world are investing in this technological revolution of energy transformation. Distributed energy technology, due to its flexibility, efficiency, and security, is becoming a key path supporting the low-carbon and intelligent development of energy. Traditional centralized energy systems, centered on fossil fuels, face structural challenges such as high transmission losses and insufficient system resilience. Distributed energy, through its user-centric layout, not only significantly improves the overall efficiency of energy utilization but also enhances grid flexibility and resilience through multi-energy complementarity and energy storage integration. Therefore, research on distributed energy has significant theoretical and practical value for building a safe, efficient, and low-carbon new energy system.

[0003] Among numerous distributed energy technologies, renewable energy technologies such as wind and solar power are limited by weather and environmental constraints, while solid oxide fuel cell technology can effectively overcome this limitation. Hybrid power generation systems combining solid oxide fuel cells and gas turbines are becoming a research hotspot in the field of distributed energy due to their significantly higher power generation efficiency compared to traditional solid oxide fuel cells, as well as their outstanding advantages such as fuel flexibility and low emissions.

[0004] In systems combining solid oxide fuel cells (SOFCs) and gas turbines, the gas turbine's threshold temperature limit (typically not exceeding 650°C) forces the SOFC and reformer to operate under extreme conditions of high pressure (0.3-1.0 MPa) and high temperature (750-950°C), significantly increasing the difficulty of system integration. Furthermore, while hydrogen is a clean and efficient anode fuel for SOFCs, it is difficult to store and transport. Therefore, an increasing number of fuels, such as methane and biomass gas, are being researched for use as anode fuels in SOFCs. However, these fuels can lead to localized carbon buildup at the SOFC anode, causing electrode blockage and shortening the SOFC's lifespan.

[0005] Therefore, a system is needed to solve the difficulties in integrating solid oxide fuel cells with gas turbines and to address the problem of localized carbon buildup at the anode of fuel cells. Summary of the Invention

[0006] To address the challenges of high-pressure integration in systems combining solid oxide fuel cells (SOFCs) and gas turbines, the significant reduction in battery life due to localized carbon buildup, and high-temperature exhaust emissions, this invention proposes an atmospheric pressure SOFC system that solves the problem of localized carbon buildup at the SOFC anode. This system effectively avoids localized carbon buildup at the SOFC anode by designing a multi-stage humidity control module. Furthermore, by optimizing the system configuration, employing a gas turbine with an integrated turbine-compressor design, and utilizing thermal energy in a cascaded manner, the high-pressure integration problem is effectively solved, thereby extending the system's lifespan and improving its efficiency.

[0007] To achieve the above objectives, this invention provides a multi-stage humidity-controlled fuel cell-gas turbine hybrid power generation system, comprising: a multi-stage humidity control module, a pre-reforming module, an internally reformed solid oxide fuel cell module, and a gas turbine module. Natural gas, after its water-to-carbon ratio is adjusted by the multi-stage humidity control module, enters the pre-reforming module. The pre-reforming module performs preliminary cracking on the natural gas, which is then fed into the internally reformed solid oxide fuel cell module to undergo reforming and electrochemical reactions, generating electricity. The high-temperature exhaust gas from the fuel cell anode and some unused fuel are fed into the gas turbine module for secondary energy utilization.

[0008] The multi-stage humidity control module includes: a fuel compressor, a heat exchanger, a water pump, a humidifier, and a separator;

[0009] The multi-stage humidity control module's fuel compressor pressurizes the natural gas fuel after it passes through the pressure reducing valve and connects it to the heat exchanger; one inlet of the humidifier is connected to the heat exchanger, and its outlet is connected to the inlet of the pre-reforming module; the other inlet is connected to the outlet of the internal reforming solid oxide fuel cell module, and its outlet is connected to the separator.

[0010] The multi-level humidity control module is used to increase the moisture in the mixed fuel, improve the fuel water-carbon ratio in the cycle, effectively avoid local carbon deposition at the SOFC anode, improve the hydrogen production rate in the reforming process and the proportion of primary energy utilization output, thereby improving system performance.

[0011] The multi-stage humidity control module utilizes the high-temperature exhaust gas from the fuel cell cathode outlet, which is then used in a pre-reformer for primary heating. Subsequently, approximately 30%-50% of the SOFC anode exhaust gas is introduced into a humidifier, where its near 1000K high temperature assists in driving the evaporation process of water within the humidifier, increasing steam yield. When the mixing system starts, cold water is supplied to the water pump, and after evaporation, it adjusts the water-to-carbon ratio of the natural gas, achieving primary humidity control. The anode exhaust gas contains a large amount of moisture; the anode exhaust gas introduced into the humidifier provides heating while simultaneously achieving secondary humidity control. Subsequently, the mixed fuel and water are separated by a separator. The mixed fuel is introduced into the gas turbine module, while the water flows into the water pump through the mixer, achieving self-balancing of the water in the mixing system. A portion of the anode exhaust gas is directly reintroduced into the mixer via a four-way splitter, where it mixes with the pre-reformed gas before entering the pre-reformer module, increasing the intake air humidity, thus achieving tertiary humidity control.

[0012] The pre-reforming module includes: a heat exchanger, a mixer, and a pre-reforming unit.

[0013] In the pre-reforming module, the heat exchanger is connected to the inlet of the pre-reforming unit after passing through the mixer, and the outlet of the pre-reforming unit is connected to the internal reforming solid oxide fuel cell module.

[0014] The pre-reforming module is heated by the high-temperature exhaust gas from the battery cathode, which is then burned twice in the combustion chamber.

[0015] In the pre-reforming module, the pre-reforming unit adopts a co-current heat exchange mode, which makes the temperature difference more uniformly distributed along the heat exchange surface, ensuring the stability of the reforming process and thus improving the module performance.

[0016] In the pre-reforming module, the heat exchanger consists of two connected heat exchangers. One is directly connected to the humidifier of the multi-stage humidity control module to realize heat exchange of the anode fuel output from the multi-stage humidity control module and treatment of the high-temperature exhaust gas discharged from the gas turbine in the gas turbine module. The other is directly connected to the mixer of the pre-reforming module to reheat the anode fuel output from the multi-stage humidity control module and to realize the transfer of high-temperature exhaust gas after the pre-reforming module provides heat.

[0017] The pre-reforming module pre-reforms the natural gas after the water-carbon ratio has been adjusted by the multi-stage humidity control module, initially decomposing multi-carbon hydrocarbon fuels and avoiding electrode blockage caused by the deposition of complex carbon chain substances in the SOFC anode chamber.

[0018] The internal reforming solid oxide fuel cell module includes: an internal reforming solid oxide fuel cell, a DC-AC inverter, an air compressor, a heat exchanger, a natural gas storage tank, and a pressure reducing valve;

[0019] In the internal reforming solid oxide fuel cell module, the air compressor is connected to the cathode inlet of the internal reforming solid oxide fuel cell via the heat exchanger; the natural gas storage tank is divided into two paths via the pressure reducing valve and a three-way splitter, one path connecting to the anode inlet of the internal reforming solid oxide fuel cell after passing through the multi-stage humidity control module and the pre-reforming module, and the other path connecting to the mixer in the gas turbine module; the cathode outlet and anode outlet of the internal reforming solid oxide fuel cell are both connected to the combustion chamber inlet via a four-way splitter; the internal reforming solid oxide fuel cell is connected to a DC-AC inverter.

[0020] In the internal reformed solid oxide fuel cell module, the air compressor is used to pressurize the air, which is then heated by a heat exchanger and used as the cathode gas of the internal reformed solid oxide fuel cell.

[0021] In the internal reforming solid oxide fuel cell module, the pressure reducing valve is used to reduce the pressure of natural gas fuel stored in the natural gas storage tank, so that it can be used by the gas turbine module;

[0022] In the internally reformed solid oxide fuel cell module, the internally reformed solid oxide fuel cell utilizes the high temperature generated by the fuel cell itself and the action of the anode catalyst to complete the reforming of the fuel inside the cell, achieving internal thermal coupling. The generated hydrogen is immediately used for electrochemical reactions to generate electricity, effectively reducing heat loss and improving the fuel cell response efficiency, thereby improving the efficiency of the hybrid system.

[0023] In the internal reforming solid oxide fuel cell module, the combustion chamber outlet is connected to the pre-reforming module; to address the insufficient exhaust heat of the fuel cell, the mixing system is equipped with an auxiliary combustion device to supplement the heat required for the operation of the pre-reforming module, providing sufficient heat for the pre-reforming reaction.

[0024] The gas turbine module includes: a condenser, a mixer, a compressor, a gas turbine, and a three-phase AC generator;

[0025] In the gas turbine module, the condenser inlet is connected to the mixed fuel separated by the multi-stage humidity control module, and the outlet is connected to the mixer; the mixer inlet is connected to the condenser and the natural gas fuel that has been depressurized by the pressure reducing valve, and the outlet is connected to the compressor inlet; the compressor outlet is connected to the gas turbine inlet; and the gas turbine outlet is connected to the three-phase alternating generator.

[0026] In the gas turbine module, the gas turbine adopts a turbine-compressor low-pressure integrated structure design, which reduces the complex layout of high-temperature gas transmission pipelines and effectively improves the energy utilization efficiency and response efficiency of the gas turbine.

[0027] The gas turbine module condenses and dehydrates the mixed fuel separated by the multi-stage humidity control module, mixes it with supplementary fuel, and then pressurizes it before finally entering the gas turbine to complete secondary power generation.

[0028] The system employs energy cascade utilization to achieve thermal self-balance, improve system stability and independence, thereby enhancing the system's energy efficiency. Simultaneously, by combining a turbine-compressor integrated gas turbine, it effectively solves the problem of system integration difficulties.

[0029] Primary energy utilization: The tail gas from the IRSOFC anode is fed into the mixer in the pre-reform module through a four-way splitter to provide heat for humidity control of natural gas fuel in the mixer;

[0030] Secondary energy utilization: The IRSOFC anode exhaust gas is introduced into the combustion chamber through a four-way splitter to provide heat for heating the battery cathode exhaust gas in the combustion chamber;

[0031] Three-stage energy utilization: The tail gas from the IRSOFC cathode enters the combustion chamber for heating and then passes into the pre-reformer in the pre-reformation module to provide thermal energy for the initial cracking of natural gas fuel; the remaining tail gas after being utilized by the pre-reformer passes through a heat exchanger and continues to be used to drive the humidity control of the humidifier.

[0032] Fourth-level energy utilization: The tail gas from the IRSOFC anode is fed into the humidifier through a three-way splitter, providing the main heat for the operation of the multi-stage humidity control module; then, water vapor and mixed fuel are separated by a separator, and the mixed fuel enters the mixer and compressor after passing through the condenser to drive the gas turbine for secondary power generation.

[0033] The gas turbine adopts an integrated structure, which reduces the complex layout of high-temperature gas transmission pipelines and effectively improves the energy utilization efficiency and response efficiency of the gas turbine. Multiple energy gradients make full use of the high-temperature and high-pressure exhaust gas generated in the system. The configuration and layout of the typical top-cycle SOFC-GT system have been optimized, thereby realizing high-pressure integration of the system.

[0034] The beneficial effects of this invention are as follows: It proposes a multi-stage humidity-controlled fuel cell gas turbine hybrid power generation system. Compared with the traditional SOFC-GT system, this system uses an integrated turbine-compressor gas turbine configuration and forms an internal thermal energy cascade utilization system, effectively avoiding the problems of unstable operating temperature and operating pressure limits of traditional systems. At the same time, it ensures that the high-temperature exhaust gas generated by the fuel cell is fully utilized, improving energy utilization efficiency. By adding a multi-stage humidity control module, it effectively improves the carbon deposition phenomenon of fuel cell anodes, significantly extending the system's service life. In addition, it also achieves water self-sufficiency in the system, enhancing the system's stability and efficiency. Attached Figure Description

[0035] Figure 1 A schematic diagram of the structure of the multi-stage humidity-controlled fuel cell gas turbine hybrid power generation system provided by the present invention.

[0036] Symbol Explanation: 1. Natural gas storage tank; 2. Pressure reducing valve; 3. Three-way splitter; 4. Fuel compressor; 5. First heat exchanger; 6. Humidifier; 7. Second heat exchanger; 8. Third heat exchanger; 9. First mixer; 10. Pre-reformer; 11. Second mixer; 12. Water pump; 13. Air compressor; 14. Fourth heat exchanger; 15. Fifth heat exchanger; 16. Internal reforming solid oxide fuel cell; 17. DC-AC inverter; 18. Combustion chamber; 19. Four-way splitter; 20. Separator; 21. Condenser; 22. Third mixer; 23. Compressor; 24. Gas turbine; 25. Three-phase alternator. Detailed Implementation

[0037] To facilitate a clearer understanding of the present invention, a more comprehensive description will be provided below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of the invention. However, the invention can be implemented in many different ways and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete disclosure of the invention.

[0038] like Figure 1 As shown, this invention designs a multi-stage humidity-controlled fuel cell-gas turbine hybrid power generation system. The system includes: a multi-stage humidity control module, a pre-reforming module, an internally reformed solid oxide fuel cell module, and a gas turbine module. The multi-stage humidity control module includes: a fuel compressor 4, a first heat exchanger 5, a humidifier 6, a water pump 12, and a separator 20; the pre-reforming module includes: a second heat exchanger 7, a third heat exchanger 8, a first mixer 9, and a pre-reforming unit 10; the internally reformed solid oxide fuel cell module includes: an internally reformed solid oxide fuel cell 16, a DC-AC inverter 17, an air compressor 13, a fourth heat exchanger 14, a fifth heat exchanger 15, a natural gas storage tank 1, and a pressure reducing valve 2; the gas turbine module includes: a condenser 21, a third mixer 22, a compressor 23, a gas turbine 24, and a three-phase AC generator 25.

[0039] The specific working process of this invention is as follows:

[0040] When the system is in a stable power generation phase, fuel is supplied by natural gas storage tank 1. After being depressurized by pressure reducing valve 2, it is divided into two streams by three-way splitter 3. One stream is supplied to the third mixer 22; the other stream is pressurized by fuel compressor 4 and heated by first heat exchanger 5 before entering humidifier 6 for water-to-carbon ratio adjustment. Then, it passes through second heat exchanger 7 and third heat exchanger 8 before entering first mixer 9 for second humidity control. After that, it enters pre-reformer 10 for preliminary reforming and finally enters internally reformed solid oxide fuel cell 16 as anode gas. Simultaneously, air compressed by compressor 13 is heated by fourth heat exchanger 14 and fifth heat exchanger 15 before being introduced into internally reformed solid oxide fuel cell 16 as cathode gas, thereby realizing power generation from the fuel cell and connecting to AD-DC inverter 17.

[0041] The high-temperature mixed fuel discharged from the fuel cell continues to utilize waste heat. Part of it is used to heat the first mixer 9, part flows into the combustion chamber 18 for re-combustion and heating to heat the pre-reformer 10, and the remainder is used as the main heat source for the humidifier 6 to drive the humidifier to evaporate water. Because the high-temperature mixed fuel at the anode contains a large amount of water, after being used by the humidifier 6, it is separated into water vapor and dehydrated mixed fuel by the separator 20. The dehydrated mixed fuel continues to be condensed by the condenser 21 and then fed into the third mixer 22. After mixing with the first stream of natural gas, it is pressurized by the compressor 23 and fed into the gas turbine 24. At the same time, a stream of fresh air is also supplied to the gas turbine 24 to ensure that the mixed fuel is fully combusted in the gas turbine 24, driving the rotor of the three-phase AC generator 25 to rotate for secondary power generation. The high-temperature cathode exhaust gas emitted from the fuel cell also utilizes waste heat. After being discharged from the internally reformed solid oxide fuel cell 16, the high-temperature cathode exhaust gas undergoes secondary combustion in the combustion chamber, and then enters the pre-reformer 10 to drive its operation. After being discharged from the pre-reformer 10, the exhaust gas is heated by the third heat exchanger 8, the fifth heat exchanger 15, and the first heat exchanger 5 to provide auxiliary heat for the humidifier 6, ensuring the stable operation of the humidifier 6. The exhaust gas is then discharged after being used by the humidifier 6. The water separated by the separator 20 enters the mixer 11 and the water pump 12 to continue supplying the humidifier, achieving water balance.

[0042] The multi-stage humidity control module includes: fuel compressor 4, first heat exchanger 5, water pump 12, humidifier 6, and separator 20;

[0043] In the multi-stage humidity control module, the fuel compressor 4 pressurizes the natural gas fuel after passing through the pressure reducing valve 2 and then connects to the first heat exchanger 5; one side inlet of the humidifier 6 is connected to the first heat exchanger 5, the outlet is connected to the inlet of the pre-reforming module, the other side inlet is connected to the outlet of the internal reforming solid oxide fuel cell module, and the outlet is connected to the separator 20.

[0044] In the multi-stage humidity control module, the high-temperature exhaust gas from the cathode outlet of the internally reformed solid oxide fuel cell 16 is used for primary heating after being processed by the pre-reformer 10. Subsequently, about 30%-50% of the SOFC anode exhaust gas is introduced into the humidifier 6, where its high temperature of nearly 1000K assists in driving the evaporation process of water within the humidifier 6, thereby increasing the steam yield. When the mixing system starts, cold water is supplied to the water pump 12, which, after evaporation, adjusts the water-to-carbon ratio of the natural gas to achieve primary humidity control. The anode exhaust gas contains a large amount of water, and the anode exhaust gas introduced into the humidifier 6 achieves secondary humidity control while simultaneously providing heating. Subsequently, the mixed fuel and water are separated by the separator 20. The mixed fuel is introduced into the gas turbine module, and the water flows into the water pump through the mixer, achieving self-balancing of the water in the mixing system. A portion of the anode exhaust gas is directly reintroduced into the first mixer 9 via the four-way splitter 19, where it is mixed with the gas before pre-reformation and then enters the pre-reformer module to increase the intake humidity, thereby achieving tertiary humidity control.

[0045] The pre-reforming module includes: a second heat exchanger 7, a third heat exchanger 8, a first mixer 9, and a pre-reforming unit 10;

[0046] In the pre-reforming module, the second heat exchanger 7 is connected to the third heat exchanger 8. The third heat exchanger 8 is connected to the inlet of the pre-reforming unit 10 after passing through the first mixer 9. The outlet of the pre-reforming unit 10 is connected to the internal reforming solid oxide fuel cell module.

[0047] In the pre-reforming module, the second heat exchanger 7 is connected to the humidifier 6 of the multi-stage humidity control module to realize the heat exchange of the anode fuel output by the multi-stage humidity control module and the treatment of the high-temperature exhaust gas discharged from the gas turbine 24 in the gas turbine module; the third heat exchanger 8 is connected to the first mixer 9 of the pre-reforming module to reheat the anode fuel output from the multi-stage humidity control module and realize the transfer of the high-temperature exhaust gas after the pre-reforming unit 10 provides heat.

[0048] The internal reforming solid oxide fuel cell module includes: an internal reforming solid oxide fuel cell 16, a DC-AC inverter 17, an air compressor 13, a fourth heat exchanger 14, a fifth heat exchanger 15, a natural gas storage tank 1, and a pressure reducing valve 2.

[0049] In the internally reformed solid oxide fuel cell module, the air compressor 13, after heat exchange through the fourth heat exchanger 14 and the fifth heat exchanger 15, is connected to the cathode inlet of the internally reformed solid oxide fuel cell 16; the natural gas storage tank 1, after passing through the pressure reducing valve 2, is divided into two paths: one path passes through the multi-stage humidity control module and the pre-reforming module and is connected to the anode inlet of the internally reformed solid oxide fuel cell 16, and the other path is connected to the third mixer 22 in the gas turbine module; the exhaust gas from the cathode outlet and the anode outlet of the internally reformed solid oxide fuel cell 16, after passing through the four-way splitter 19, is connected to the inlet of the combustion chamber 18; the internally reformed solid oxide fuel cell 16 is connected to the DC-AC inverter 17.

[0050] In the internal reformed solid oxide fuel cell module, the air compressor 13 is used to pressurize the air, which is then heated by the fourth heat exchanger 14 and the fifth heat exchanger 15 and used as the cathode gas of the internal reformed solid oxide fuel cell 16.

[0051] In the internal reforming solid oxide fuel cell module, pressure reducing valve 2 is used to reduce the pressure of natural gas fuel stored in the natural gas storage tank, so that it can be used by the gas turbine module;

[0052] In the internal reforming solid oxide fuel cell module, the combustion chamber 18 outlet is connected to the pre-reforming module; to address the insufficient exhaust heat of the fuel cell, the mixing system is equipped with an auxiliary combustion device to supplement the heat required for the pre-reforming module to work, providing sufficient heat for the pre-reforming reaction.

[0053] The gas turbine module includes: a condenser 21, a third mixer 22, a compressor 23, a gas turbine 24, and a three-phase alternator 25;

[0054] In the gas turbine module, the inlet of condenser 21 is connected to the mixed fuel separated by the multi-stage humidity control module, and the outlet is connected to the third mixer 22; the inlet of the third mixer 22 is connected to the outlet of condenser 21 and the outlet of three-way splitter 3, the outlet is connected to the inlet of compressor 23, the outlet of compressor 23 is connected to the inlet of gas turbine 24, and the outlet of gas turbine 24 is connected to three-phase alternating generator 25.

[0055] In the gas turbine module, the gas turbine 24 adopts a turbine-compressor low-pressure integrated structure design, which reduces the complex layout of high-temperature gas transmission pipelines and effectively improves the energy utilization efficiency and response efficiency of the gas turbine.

[0056] In the gas turbine module, the mixed fuel separated by the multi-stage humidity control module is condensed and dehydrated by the condenser 21, then mixed with supplementary fuel in the third mixer 22 and pressurized by the compressor 23 before finally entering the gas turbine 24 to complete secondary power generation.

[0057] The system adopts multi-stage waste heat recovery to achieve thermal self-balance, improve system stability and independence, thereby improving the system's energy utilization efficiency. At the same time, it is combined with the turbine-compressor integrated gas turbine 24 to effectively solve the problem of system integration difficulty.

[0058] Primary energy utilization: The tail gas from the anode of the internally reformed solid oxide fuel cell 16 is fed into the first mixer 9 in the pre-reformation module through a four-way splitter 19, providing heat for the humidity control of natural gas fuel in the first mixer 9.

[0059] Secondary energy utilization: The tail gas from the anode of the internally reformed solid oxide fuel cell 16 is introduced into the combustion chamber 18 through the four-way splitter 19, providing heat for the combustion chamber 18 to heat the tail gas from the cathode of the battery.

[0060] Three-stage energy utilization: The tail gas from the cathode of the internally reformed solid oxide fuel cell 16 enters the combustion chamber 18 for heating and then passes into the pre-reformer 10 in the pre-reformation module to provide thermal energy for the initial cracking of natural gas fuel; the remaining tail gas after being utilized by the pre-reformer passes through the third heat exchanger 8, the fifth heat exchanger 15 and the first heat exchanger 5 and continues to be used to drive the humidity control of the humidifier.

[0061] Fourth-level energy utilization: The tail gas from the anode of the internally reformed solid oxide fuel cell 16 is fed into the humidifier 6 through the three-way splitter 3, providing the main heat for the operation of the multi-stage humidity control module; then, water vapor and mixed fuel are separated by the separator 20, and the mixed fuel enters the third mixer 22 and compressor 23 after passing through the condenser 21, and then drives the gas turbine 24 to generate electricity for the second time.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art related to this invention. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0063] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0064] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A multi-stage humidity-conditioned fuel cell gas turbine hybrid power system, characterized by, The system comprises a multi-stage humidity control module, a pre-reforming module, an internal reforming solid oxide fuel cell module, and a gas turbine module. The natural gas is adjusted in water-carbon ratio by a humidifier, and then enters the pre-reforming module. The pre-reforming module performs preliminary cracking on the natural gas, and then the natural gas enters the internal reforming solid oxide fuel cell module to perform reforming and electrochemical reaction, thereby generating electric energy. The high-temperature exhaust gas discharged from the anode of the fuel cell and part of the unused fuel enter the gas turbine module to perform secondary energy utilization. The multi-stage humidity control module comprises a fuel compressor, a first heat exchanger, a water pump, a humidifier, and a separator. The fuel compressor is connected with the first heat exchanger after pressurizing the natural gas after the pressure reducing valve. The humidifier is connected with the first heat exchanger at one side inlet, and is connected with the pre-reforming module at the outlet. The other side inlet of the humidifier is connected with the outlet of the internal reforming solid oxide fuel cell module, and the outlet is connected with the separator.

2. The system of claim 1, wherein, The multi-stage humidity control module comprises three-stage humidity control.

3. The system of claim 2, wherein, The first-stage humidity control comprises adjusting the water-carbon ratio of the methane fuel in the natural gas by evaporating the cold water provided by the water pump when the system is started. The second-stage humidity control comprises adjusting the humidity by the anode exhaust gas entering the humidifier to complete heat supply. The third-stage humidity control comprises separating the mixed fuel and water by the separator, and then the mixed fuel enters the gas turbine module, and the water flows into the water pump through the mixer to realize self-supply of the mixed system water. Part of the anode exhaust gas directly re-enters the mixer through a recirculation loop, mixes with the gas before the pre-reforming, and then enters the pre-reforming module to improve the humidity of the inlet gas.

4. The system of claim 1, wherein, The pre-reforming module comprises a heat exchanger, a mixer, and a pre-reformer. The heat exchanger is connected with the pre-reformer inlet after passing through the mixer, and the pre-reformer outlet is connected with the internal reforming solid oxide fuel cell module. The pre-reformer adopts a parallel flow heat exchange mode.

5. The system of claim 1, wherein, The heat exchanger of the pre-reforming module is connected in series with a second heat exchanger and a third heat exchanger. The second heat exchanger is directly connected with the humidifier in the multi-stage humidity control module to realize heat exchange of the anode fuel output by the multi-stage humidity control module and treatment of the high-temperature exhaust gas discharged from the gas turbine in the gas turbine module. The third heat exchanger is directly connected with the mixer of the pre-reforming module to heat the anode fuel output from the multi-stage humidity control module again, thereby realizing transmission of the high-temperature exhaust gas after heat supply of the pre-reformer.

6. The system of claim 1, wherein, The internal reforming solid oxide fuel cell module comprises an internal reforming solid oxide fuel cell, a DC-AC inverter, an air compressor, a heat exchanger, a natural gas storage tank, and a pressure reducing valve. The air compressor is connected with the cathode inlet of the internal reforming solid oxide fuel cell through the heat exchanger. The natural gas storage tank is divided into two paths by a three-way flow divider after passing through the pressure reducing valve. One path is connected with the anode inlet of the internal reforming solid oxide fuel cell after passing through the multi-stage humidity control module and the pre-reforming module. The other path is connected with the mixer in the gas turbine module. The cathode outlet and the anode outlet of the internal reforming solid oxide fuel cell are connected with the inlet of the combustion chamber after passing through a four-way flow divider. The internal reforming solid oxide fuel cell is connected with the DC-AC inverter.

7. The system of claim 6, wherein, The combustion chamber outlet is connected with the pre-reforming module; for the working condition that the fuel cell exhaust heat is insufficient, the auxiliary combustion device is arranged in the mixed system to supplement the heat required by the pre-reforming module, so as to provide sufficient heat for the pre-reformer reaction.

8. The system of claim 1, wherein, The gas turbine module comprises a condenser, a mixer, a compressor, a gas turbine and a three-phase alternating current generator. The condenser inlet is connected with the mixed fuel separated by the multi-stage humidity control module, and the condenser outlet is connected with the mixer; the mixer inlet is connected with the condenser and the natural gas fuel reduced by the pressure reducing valve, and the mixer outlet is connected with the compressor inlet; the compressor outlet is connected with the gas turbine inlet, and the gas turbine outlet is connected with the three-phase alternating current generator. The module mixes the mixed fuel separated by the multi-stage humidity control module after condensation and dehydration treatment with the supplementary fuel, and then the mixture is input into the fuel compressor for pressurization, and finally into the gas turbine for secondary power generation.

9. The system of claim 8, wherein, The gas turbine adopts a turbine-compressor low-pressure integrated structure design, which reduces the complex arrangement of high-temperature gas conveying pipelines.

10. The system of any of claims 1-9, wherein, The four-stage energy utilization comprises: the anode tail gas of the internal reforming solid oxide fuel cell is input into the first mixer in the pre-reforming module through a four-way shunt, so as to provide heat for the humidity control of the natural gas fuel in the first mixer; The second-stage energy utilization comprises: the anode tail gas of the internal reforming solid oxide fuel cell is input into the combustion chamber through a four-way shunt, so as to provide heat for heating the cathode tail gas of the cell in the combustion chamber; The third-stage energy utilization comprises: the cathode tail gas of the internal reforming solid oxide fuel cell is input into the pre-reformer in the pre-reforming module after heating in the combustion chamber, so as to provide heat energy for the preliminary cracking of the natural gas fuel; the remaining tail gas after the utilization of the pre-reformer is continuously used to drive the humidifier for humidity control after passing through the third heat exchanger, the fifth heat exchanger and the first heat exchanger; The fourth-stage energy utilization comprises: the anode tail gas of the internal reforming solid oxide fuel cell is input into the humidifier through a three-way shunt, so as to provide main heat for the working of the multi-stage humidity control module; then the water vapor and the mixed fuel are separated by the separator, and the mixed fuel is input into the third mixer after passing through the condenser, and then drives the gas turbine for secondary power generation.

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