Hybrid power system and design method of a gas turbine coupled to a solid oxide fuel cell

Abstract

A hybrid power system of gas turbine coupled with solid oxide fuel cell and design method belong to the field of ship power system, which comprises a gas turbine subsystem, a solid oxide fuel cell subsystem, a battery cathode air flow and pressure regulating valve, a regenerator and a high temperature heat exchanger. The solid oxide fuel cell subsystem comprises a solid oxide fuel cell, a pre-reformer, a supplementary combustion chamber, a fuel preheater and an ejector, and the solid oxide fuel cell comprises a cathode, an anode and a membrane electrode; the gas turbine subsystem comprises an air inlet, a compressor, a combustion chamber, a high pressure turbine and a power turbine; the hybrid power system is suitable for both split-shaft gas turbine and three-shaft gas turbine. The application can realize the single operation of the gas turbine to meet the requirements of ship gas turbine fast navigation and combat, and can realize the combined operation of the gas turbine and the solid oxide fuel cell hybrid power system to meet the green development goal of high efficiency and low emission of the ship power system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ship power systems, and particularly relates to a hybrid power system of a gas turbine coupled with a solid oxide fuel cell and a design method. BACKGROUND

[0002] At present, the gas turbine has been widely used in ship propulsion systems due to its high power density, fast response and high thermal efficiency, and has important application value in the fields of high-speed ships, patrol ships and power generation devices. The ship gas turbine mainly adopts the technology derived from aviation turbine engines, and has the characteristics of large power-to-weight ratio, fast start-stop, rapid response to working conditions and high reliability. However, based on the green development demand of the ship field, the gas turbine technology will develop towards higher cycle efficiency and lower pollution emission. Fuel cells, as a power generation device with high power generation efficiency, low environmental pollution, high specific energy, low noise, high reliability and easy construction, are a new direction for the development of future ship integrated electric propulsion systems. Therefore, the ship power device can increase the fuel cell system to propose a "gas turbine + battery / fuel cell" hybrid power system architecture, which can greatly improve the ship power cycle system efficiency, reduce noise and pollution emissions.

[0003] The hybrid power system of the solid oxide fuel cell and the gas turbine currently studied mainly includes a top cycle architecture and a bottom cycle architecture, and the top cycle architecture is widely concerned by scholars due to its high cycle efficiency. The gas turbine compressor provides the required air for the solid oxide fuel cell, and the solid oxide fuel cell generator is composed of multiple tubular solid fuel cells. Gaseous fuel (such as pipeline natural gas or diesel) and air undergo an electrochemical reaction inside the cell to generate electricity, and the waste heat gas discharged by the electrochemical reaction drives the gas turbine to work. The gas turbine and the solid oxide fuel cell jointly output power. Patent CN114665120A proposes a multi-fuel solid oxide fuel cell and gas turbine hybrid power generation system, which combines the high-temperature exhaust gas of the solid oxide fuel cell with the gas turbine. The above two patents both belong to the top cycle architecture type.

[0004] The above-mentioned solid oxide fuel cell and gas turbine top cycle architecture belongs to a fully coupled architecture type, and the gas turbine and the solid oxide fuel cell cannot work independently, and the gas turbine does not have a combustion chamber. However, in the existing ship gas turbine power system, it is not realistic to use a solid oxide fuel cell and a gas turbine to form a fully coupled hybrid power system. First, the existing ship gas turbine is the main power source, and the combustion chamber is an important high-temperature component. The high-temperature gas generated by the combustion chamber drives the gas turbine turbine to output power to meet the various cruising, accelerating and decelerating navigation and other combat requirements of the ship. Second, the solid oxide fuel cell and gas turbine hybrid power system in the top cycle still needs to be improved in dynamic response, heat management and fuel adaptability. Therefore, under the guidance of the green development demand in the field of ships, on the premise of maintaining the existing ship gas turbine power system and its combat capability, a new architecture type of gas turbine and solid oxide fuel cell hybrid power system and its design method still belong to the blank. SUMMARY

[0005] The present application can be applied to the design field of the existing ship gas turbine power system. In view of the limitations of the aforementioned solid oxide fuel cell and gas turbine top cycle architecture on the maneuverability requirements of the existing ship gas turbine power system, a gas turbine coupled solid oxide fuel cell hybrid power system and design method are proposed. The technical scheme of the present application is to use the inter-stage bleeding of the compressor of the split-shaft gas turbine or the partial exhaust of the low-pressure compressor of the three-shaft gas turbine as the cathode working medium of the solid oxide fuel cell. The exhaust after the electrochemical reaction is all sent to the inlet of the gas turbine power turbine, forming a parallel architecture layout of the gas turbine and the solid oxide fuel cell. The architecture design method based on the gas turbine and solid oxide fuel cell hybrid power system ensures the cooperative work of the gas turbine and the solid oxide fuel cell.

[0006] The object of the present application can be achieved by the following technical scheme:

[0007] A gas turbine coupled solid oxide fuel cell hybrid power system, comprising a gas turbine subsystem, a solid oxide fuel cell subsystem, a battery cathode air flow and pressure regulating valve 3, a regenerator 4 and a high-temperature heat exchanger 5. The solid oxide fuel cell subsystem comprises a solid oxide fuel cell 6, a pre-reformer 14, a supplementary combustion chamber 15, a fuel preheater 12 and an ejector 13, and the solid oxide fuel cell 6 comprises a cathode 61, an anode 63 and a membrane electrode 62; the gas turbine subsystem comprises an air inlet 1, a compressor, a combustion chamber 8, a high-pressure turbine 9 and a power turbine 11; the hybrid power system is suitable for both split-shaft gas turbines and three-shaft gas turbines, and when it is suitable for three-shaft gas turbines, a three-shaft gas turbine low-pressure compressor 2 and a low-pressure turbine 10 need to be added.

[0008] The compressor is used for compressing the air sent by the air inlet 1, and a part of the air is led out from the inter-stage of the split-shaft gas turbine compressor 16 or the exhaust port of the low-pressure compressor 2 of the three-shaft gas turbine, is adjusted by the battery cathode air flow and pressure adjusting valve 3, and is sequentially supplied to the cathode 61 of the solid oxide fuel cell 6 of the solid oxide fuel cell subsystem to participate in the electrochemical reaction after passing through the regenerator 4 and the high-temperature heat exchanger 5, the remaining air is compressed by the subsequent stage of the split-shaft gas turbine compressor 16 or the high-pressure compressor 7 of the three-shaft gas turbine, and then enters the combustion chamber 8, and the outlet gas of the combustion chamber 8 enters the high-pressure turbine 9; the tail gas generated by the cathode 61 and the anode 63 after the electrochemical reaction of the solid oxide fuel cell 6 is sent to the afterburning chamber 15 to completely oxidize the combustible components in the tail gas, the high-temperature gas is discharged from the afterburning chamber 15, and the heat is released after heat exchange through the high-temperature heat exchanger 5, and then the high-temperature gas is sent to the inlet of the power turbine 11 together with the outlet gas of the high-pressure turbine 9 to continue to expand and work in the power turbine 11, and drive the generator to output power to the outside; the tail gas discharged from the power turbine 11 is first discharged to the atmosphere after heat release through the regenerator 4 and heating of the fuel used by the solid oxide fuel cell 6 through the fuel preheater 12; the fuel used by the solid oxide fuel cell 6 sequentially passes through the fuel preheater 12, the injector 13 and the pre-reformer 14 to enter the anode 63 of the solid oxide fuel cell 6; the regenerator 4 and the high-temperature heat exchanger 5 are arranged to utilize the waste heat of the exhaust gas of the power turbine 11 to sequentially heat the air input to the cathode of the solid oxide fuel cell and the anode fuel, thereby completing the architecture design of the gas turbine and solid oxide fuel cell hybrid power system. When the split-shaft gas turbine is used, the outlet gas of the high-pressure turbine 9 is directly sent to the inlet of the power turbine 11, and when the three-shaft gas turbine is used, the outlet gas of the high-pressure turbine 9 needs to pass through the low-pressure turbine 10 first and then be sent to the inlet of the power turbine 11.

[0009] Further, during the operation of the system, the anode fuel is heated by the fuel preheater 12, is fully mixed with the recirculation gas flow of the anode 63 of the solid oxide fuel cell 6 in the injector 13, and is then injected into the pre-reformer 14.

[0010] A design method of a gas turbine coupled solid oxide fuel cell hybrid power system, comprising the following steps:

[0011] Step 1, according to the shaft structure of the ship gas turbine, the gas turbine heat balance calculation method is used to determine the node parameters of the gas turbine coupled solid oxide fuel cell hybrid power system under the full working condition of the gas turbine, the pressure variation range after each stage of the gas turbine compressor and before the power turbine is obtained, and the working pressure interval of the solid oxide fuel cell is proposed;

[0012] Step 2: Based on the operating pressure range of the solid oxide fuel cell obtained in Step 1, and to ensure that the solid oxide fuel cell operates stably and safely, propose the location of the bleed point of the split-shaft gas turbine compressor, or combine the outlet air pressure of the low-pressure compressor of the three-shaft gas turbine to further determine the stable operating pressure of the solid oxide fuel cell.

[0013] Step 3: Based on the stable operating pressure of the solid oxide fuel cell determined in Step 2, propose an adjustment scheme for the stable operating pressure of the cathode air of the solid oxide fuel cell. Based on the system modeling method of thermodynamics, heat transfer and electrochemical coupling, obtain the optimal power matching scheme between the gas turbine and the solid oxide fuel cell.

[0014] The beneficial effects of this invention are:

[0015] (1) It can realize the independent operation of the gas turbine to meet the needs of rapid navigation and combat of the ship's gas turbine, and can also realize the joint operation of the gas turbine and the solid oxide fuel cell hybrid power system to meet the green development goal of high efficiency and low emissions of the ship's power system.

[0016] (2) The high-temperature exhaust gas from the gas turbine is used to heat the air and fuel of the solid oxide fuel cell, which reduces the exhaust gas temperature, improves the cycle efficiency of the hybrid power system of gas turbine coupled with solid oxide fuel cell, and ensures the solid oxide fuel cell's operating temperature requirements. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a hybrid power system architecture consisting of a split-shaft gas turbine coupled with a solid oxide fuel cell.

[0018] Figure 2 This is a schematic diagram of a hybrid power system architecture consisting of a three-shaft gas turbine coupled with a solid oxide fuel cell.

[0019] In the diagram: 1-Intake; 2-Low-pressure compressor of a three-shaft gas turbine; 3-Cathode air flow and pressure regulating valve; 4-Regenerator; 5-High-temperature heat exchanger; 6-Solid oxide fuel cell; 61-Cathode; 62-Membrane electrode; 63-Anode; 7-High-pressure compressor of a three-shaft gas turbine; 8-Combustion chamber; 9-High-pressure turbine; 10-Low-pressure turbine; 11-Power turbine; 12-Fuel preheater; 13-Injector; 14-Pre-reformer; 15-Afterburner; 16-Split-shaft gas turbine compressor. Detailed Implementation

[0020] The following is in conjunction with the appendix Figure 1 The specific embodiments of the present invention will be further described below, along with the technical solutions.

[0021] Example 1:

[0022] like Figure 1 As shown, this invention includes a hybrid power system of a gas turbine coupled with a solid oxide fuel cell, comprising a split-shaft gas turbine subsystem, a solid oxide fuel cell subsystem, a battery cathode air flow and pressure regulating valve 3, a regenerator 4, and a high-temperature heat exchanger 5. The split-shaft gas turbine subsystem includes an intake duct 1, a split-shaft gas turbine compressor 16, a combustion chamber 8, a high-pressure turbine 9, and a power turbine 11. The split-shaft gas turbine compressor 16 is coaxially connected to the high-pressure turbine 9. The intake duct 1 is open to the outside atmosphere, and the power turbine 11 is connected to a generator to output electrical power. The solid oxide fuel cell subsystem includes an injector 13, a pre-reformer 14, a solid oxide fuel cell 6, a fuel preheater 12, and a combustion chamber 15.

[0023] The split-shaft gas turbine compressor 16 is used to compress the air supplied by the intake duct 1. A portion of the pressurized air is drawn out through the interstage of the split-shaft gas turbine compressor 16, and the flow and pressure of the bleed air are regulated by the battery cathode air flow and pressure regulating valve 3 to meet the design requirements of the solid oxide fuel cell subsystem. The remaining air continues to be compressed in the subsequent stages of the split-shaft gas turbine compressor 16. The exhaust gas is burned with fuel in the combustion chamber 8, and the high-temperature gas produced enters the inlet of the high-pressure turbine 9, which can ensure the independence of the gas turbine power output.

[0024] The gas from the split-shaft gas turbine compressor 16, after being bleeded, is heated by the battery cathode air flow and pressure regulating valve 3, the regenerator 4, and the high-temperature heat exchanger 5 before entering the solid oxide fuel cell cathode 61. The fuel, heated by the fuel preheater 12, is thoroughly mixed with the recirculated gas flow from the solid oxide fuel cell anode 63 in the injector 13 and injected into the pre-reformer 14. In the pre-reformer 14, the fuel undergoes a water-vapor shift reaction with the high-temperature water vapor in the anode recirculated gas flow, generating a large amount of hydrogen. This hydrogen then enters the anode 63 and undergoes an electrochemical reaction with oxygen from the air at the cathode 61 via the membrane electrode 62. After the reaction, the exhaust gases from the cathode 61 and anode 63 enter the afterburner 15 together. Unreacted combustibles in the exhaust gases are further oxidized into high-temperature fuel gas in the afterburner 15, releasing heat through the high-temperature heat exchanger 5 and being sent to the exhaust line of the high-pressure turbine 9. This fuel gas mixes with the outlet gas from the high-pressure turbine 9 and is then sent to the power turbine 11. This provides a method for parallel power output between a gas turbine subsystem and a solid oxide fuel cell system.

[0025] The exhaust gas discharged from the power turbine 11 still has a large amount of residual heat. This exhaust gas is first heated by the regenerator 4, and then heated by the fuel preheater 12 to heat the fuel used in the solid oxide fuel cell 6 before being discharged into the atmosphere.

[0026] Example 2:

[0027] likeFigure 2 As shown, this invention includes a hybrid power system of a gas turbine coupled with a solid oxide fuel cell, comprising a three-shaft gas turbine subsystem, a solid oxide fuel cell subsystem, a battery cathode air flow and pressure regulating valve 3, a regenerator 4, and a high-temperature heat exchanger 5. The three-shaft gas turbine subsystem includes an intake duct 1, a three-shaft gas turbine low-pressure compressor 2, a three-shaft gas turbine high-pressure compressor 7, a combustion chamber 8, a high-pressure turbine 9, a low-pressure turbine 10, and a power turbine 11. The three-shaft gas turbine low-pressure compressor 2 is coaxially connected to the low-pressure turbine 10, and the three-shaft gas turbine high-pressure compressor 7 is coaxially connected to the high-pressure turbine 9. The intake duct 1 is open to the outside atmosphere, and the power turbine 11 is connected to a generator to output electrical power. The solid oxide fuel cell subsystem includes a pre-injector 13, a pre-reformer 14, a solid oxide fuel cell 6, a fuel preheater 12, and a combustion chamber 15.

[0028] The low-pressure compressor 2 of the three-shaft gas turbine is used to compress the air sent in through the intake duct 1, and then draw out a portion of the gas to be sent to the solid oxide fuel cell. During this process, the flow and pressure of the gas are regulated by the battery cathode air flow and pressure regulating valve 3 to meet the design requirements of the solid oxide fuel cell subsystem. The remaining air enters the high-pressure compressor 7 of the three-shaft gas turbine for further compression. The exhaust gas is burned with fuel in the combustion chamber 8, and the resulting high-temperature gas enters the inlet of the high-pressure turbine 9 and then enters the low-pressure turbine 10 in the three-shaft gas turbine, which can ensure the independence of the gas turbine's power output.

[0029] The gas drawn from the outlet of the low-pressure compressor 2 of the three-shaft gas turbine is heated by the battery cathode air flow and pressure regulating valve 3, the regenerator 4, and the high-temperature heat exchanger 5 before entering the cathode 61 of the solid oxide fuel cell. After being heated by the fuel preheater 12, the fuel is fully mixed with the recirculated gas flow from the anode 63 of the solid oxide fuel cell 6 in the injector 13 and injected into the pre-reformer 14. In the pre-reformer 14, the fuel undergoes a water-vapor shift reaction with the high-temperature water vapor in the anode recirculated gas flow to generate a large amount of hydrogen, which then enters the anode 63 and undergoes an electrochemical reaction with oxygen from the air from the cathode 61 through the membrane electrode 62. After the reaction, the exhaust gas from the cathode 61 and the anode 63 enters the combustion chamber 15 together. The unreacted combustibles in the exhaust gas will continue to be completely oxidized into high-temperature gas in the combustion chamber 15 and release heat through the high-temperature heat exchanger 5. The gas is then sent to the exhaust line of the low-pressure turbine 10 and mixed with the outlet gas of the low-pressure turbine 10 before being sent to the power turbine 11. A method is provided for parallel power output of a gas turbine subsystem and a solid oxide fuel cell system.

[0030] The exhaust gas discharged from the power turbine 11 still has a large amount of residual heat. This exhaust gas is first heated by the regenerator 4, and then heated by the fuel preheater 12 to heat the fuel used in the solid oxide fuel cell 6 before being discharged into the atmosphere.

[0031] Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, any equivalent structural modifications made using the description and drawings of the present invention, whether directly or indirectly applied to other related technical fields, are similarly included within the protection scope of the present invention.

Claims

1. A hybrid power system of a gas turbine coupled with a solid oxide fuel cell, characterized in that, The system includes a gas turbine subsystem, a solid oxide fuel cell subsystem, a battery cathode air flow and pressure regulating valve (3), a regenerator (4), and a high-temperature heat exchanger (5); the solid oxide fuel cell subsystem includes a solid oxide fuel cell (6), a pre-reformer (14), a combustion chamber (15), a fuel preheater (12), and an injector (13); the solid oxide fuel cell (6) includes a cathode (61), an anode (63), and a membrane electrode assembly (62); the gas turbine subsystem includes an intake duct (1), a compressor, a combustion chamber (8), a high-pressure turbine (9), and a power turbine (11); the hybrid power system is applicable to both split-shaft gas turbines and three-shaft gas turbines. When applicable to three-shaft gas turbines, a three-shaft gas turbine low-pressure compressor (2) and a low-pressure turbine (10) need to be added. The compressor is used to compress the air fed into the intake duct (1). A portion of the air is drawn from the exhaust port of the interstage compressor (16) of the split-shaft gas turbine or the low-pressure compressor (2) of the three-shaft gas turbine. After being regulated by the battery cathode air flow and pressure regulating valve (3), the air passes through the regenerator (4) and the high-temperature heat exchanger (5) in sequence, and is supplied to the cathode (61) of the solid oxide fuel cell (6) of the solid oxide fuel cell subsystem to participate in the electrochemical reaction. The remaining air is compressed by the subsequent stage of the split-shaft gas turbine compressor (16) or the high-pressure compressor (7) of the three-shaft gas turbine and enters the combustion chamber (8). All the gas at the outlet of the combustion chamber (8) enters the high-pressure turbine (9). The exhaust gas generated by the cathode (61) and anode (63) of the solid oxide fuel cell (6) after the electrochemical reaction is sent to the combustion chamber (15) to completely oxidize the combustible components in the exhaust gas. The combustion chamber (15) discharges high-temperature gas and passes through the combustion chamber (15). After heat exchange in the high-temperature heat exchanger (5), the heat is released and then sent to the inlet of the power turbine (11) together with the outlet gas of the high-pressure turbine (9). The power turbine (11) continues to expand and do work, driving the generator to output electricity. The exhaust gas discharged from the power turbine (11) is first heated by the regenerator (4) and then heated by the fuel preheater (12) before being discharged into the atmosphere. The fuel used by the solid oxide fuel cell (6) is sent to the anode (63) of the solid oxide fuel cell (6) in sequence through the fuel preheater (12), the injector (13), and the pre-reformer (14). When a split-shaft gas turbine is used, the outlet gas of the high-pressure turbine (9) is directly sent to the inlet of the power turbine (11). When a three-shaft gas turbine is used, the outlet gas of the high-pressure turbine (9) needs to pass through the low-pressure turbine (10) before being sent to the inlet of the power turbine (11).

2. The hybrid power system of a gas turbine coupled with a solid oxide fuel cell according to claim 1, characterized in that, During system operation, the anode fuel is heated by the fuel preheater (12) and then fully mixed with the recirculated gas flow of the anode (63) of the solid oxide fuel cell (6) in the injector (13) before being injected into the pre-reformer (14).

3. The design method of a hybrid power system of a gas turbine coupled with a solid oxide fuel cell as described in claim 1 or 2, characterized in that, Includes the following steps: Step 1: Based on the ship's gas turbine shaft system structure, the gas turbine thermal balance calculation method is used to determine the node parameters of the hybrid power system coupled with the gas turbine and solid oxide fuel cell under all operating conditions. The pressure variation range after each stage of the gas turbine compressor and before the power turbine is obtained, and the working pressure range of the solid oxide fuel cell is proposed. Step 2: Based on the operating pressure range of the solid oxide fuel cell obtained in Step 1, and to ensure that the solid oxide fuel cell operates stably and safely, propose the location of the bleed point of the split-shaft gas turbine compressor, or combine the outlet air pressure of the low-pressure compressor of the three-shaft gas turbine to further determine the stable operating pressure of the solid oxide fuel cell. Step 3: Based on the stable operating pressure of the solid oxide fuel cell determined in Step 2, propose an adjustment scheme for the stable operating pressure of the cathode air of the solid oxide fuel cell. Based on the system modeling method of thermodynamics, heat transfer and electrochemical coupling, obtain the optimal power matching scheme between the gas turbine and the solid oxide fuel cell.

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