Hydrogen fuel solid oxide fuel cell (SOFC) actual combined cycle power generation system based on gas turbine pressurization

Abstract

The invention discloses a hydrogen fuel SOFC actual combined cycle power generation system based on gas turbine pressurization, and belongs to the technical field of energy power equipment. In the starting stage, air is compressed by a gas compressor and then enters a combustion chamber to be combusted with hydrogen, exhausted gas is introduced into a turbine to do work, electric energy is provided for temperature rise before SOFC reaction through a motor, and turbine exhausted gas sequentially heats hydrogen and air at an inlet of the combustion chamber. Under the stable operation working condition, air sequentially passes through a gas compressor, a flow divider and a heat exchanger to be introduced into an SOFC cathode, hydrogen is heated through the heat exchanger and enters an SOFC anode to be subjected to an oxidation reaction, cathode and anode tail gas and supplemented gas enter a combustion chamber to be combusted, exhaust gas enters a turbine to do work and then is exhausted, and turbine exhaust gas sequentially heats hydrogen of SOFC anode inlet gas and air of cathode inlet gas; wherein the SOFC anode tail gas heats hydrogen supplemented by the combustion chamber through the heat exchanger, and the SOFC cathode tail gas heats air supplemented by the combustion chamber through the heat exchanger.

Description

Technical Field

[0001] This invention relates to the field of energy and power equipment technology, and in particular to a hydrogen fuel SOFC based on gas turbine pressurization. Actual combined cycle power generation system. Background Technology

[0002] As the global energy structure shifts towards low-carbon and high-efficiency energy, hydrogen energy, as a typical representative of zero-carbon fuels, is becoming an important carrier of the clean energy system.

[0003] Fuel cells directly and efficiently convert chemical energy into electrical energy without combustion. Their energy conversion efficiency is not limited by the Carnot cycle, resulting in a very high energy conversion rate. They are considered one of the new, highly efficient, energy-saving, and environmentally friendly power generation methods of the 21st century. Among various fuel cells, solid oxide fuel cells (SOFCs) are considered the core device of next-generation distributed power generation technology due to their high efficiency, fuel flexibility, and the ability to utilize high-temperature waste heat. However, traditional SOFC standalone power generation systems suffer from insufficient waste heat utilization and limited system dynamic response, hindering their large-scale application. Meanwhile, gas turbine (GT) combined cycle systems, while possessing high cycle efficiency, still rely on fossil fuels, resulting in significant carbon emissions, and their thermodynamic cycle efficiency is approaching its theoretical limit.

[0004] Against this backdrop, deeply coupling hydrogen fuel SOFC with gas turbines to build a new type of combined cycle power generation system has become an important direction for breaking through existing technological limitations and achieving efficient zero-carbon power generation. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention proposes a hydrogen fuel SOFC combined cycle power generation system based on gas turbine pressurization, aiming to achieve a dual breakthrough in energy cascade utilization and zero carbon emissions, thereby improving the system's energy utilization efficiency. Make full use of waste heat to achieve energy saving in the system.

[0006] The technical solution adopted by the present invention to solve the above problems is as follows: This invention proposes a hydrogen fuel SOFC combined cycle power generation system based on gas turbine pressurization, comprising a compressor, a first distributor, a pressure reducing valve, a second distributor, a first heat exchanger, a second heat exchanger, a combustion chamber, a turbine, a generator, a third heat exchanger, a solid oxide fuel cell, a fourth heat exchanger, a fifth heat exchanger, a DC-AC converter, a sixth heat exchanger, a third distributor, a first hydrogen cylinder, and a second hydrogen cylinder; The compressor outlet is connected to the inlet of the first distributor. One outlet of the first distributor is connected to a pressure reducing valve, and the other outlet is connected to the cold-side inlet of the third heat exchanger. The pressure reducing valve outlet is connected to the inlet of the second distributor. One outlet of the second distributor is connected to the cooling air inlet of the combustion chamber. The other outlet is connected sequentially to the cold sides of the first and second heat exchangers and then to the combustion air inlet of the combustion chamber. The combustion chamber outlet is connected to the turbine inlet. The turbine is coaxially connected to the compressor and drives the generator. The turbine outlet is connected to the inlet of the third distributor. The third distributor is connected in sequence to the hot-side inlet of the sixth heat exchanger and the hot-side inlet of the second heat exchanger during startup; the third distributor is connected in sequence to the hot-side inlet of the fifth heat exchanger and the hot-side inlet of the third heat exchanger during stable operation. The outlet of the second hydrogen cylinder is connected in sequence to the hydrogen inlets of the fourth and sixth heat exchangers and then into the combustion chamber; the outlet of the first hydrogen cylinder is connected to the cold side inlet of the fifth heat exchanger; the hot side outlet of the fifth heat exchanger is connected to the anode inlet of the solid oxide fuel cell; the power output terminal of the solid oxide fuel cell is connected to the DC-AC converter. The cathode outlet of the solid oxide fuel cell is connected to the first heat exchanger, the cathode inlet of the solid oxide fuel cell is connected to the hot-side outlet of the third heat exchanger, and the anode outlet of the solid oxide fuel cell is connected to the fourth heat exchanger.

[0007] Furthermore, during startup, after being compressed by the compressor, the air passes through the first distributor and the pressure reducing valve in sequence. At this time, the pressure reducing valve is not working, and the air is divided into two paths by the second distributor. One part of the air directly enters the combustion chamber for cooling; the other part of the air passes through the first heat exchanger and is heated in the second heat exchanger before entering the combustion chamber. At the same time, the hydrogen from the second hydrogen cylinder passes through the fourth heat exchanger and is heated in the sixth heat exchanger before entering the combustion chamber. The hydrogen and air burn in the combustion chamber. The exhaust gas from the combustion chamber enters the turbine to do work, driving the generator to provide electrical energy for heating the solid oxide fuel cell before the reaction. The turbine exhaust gas passes through the third splitter, then sequentially through the sixth and second heat exchangers before being discharged, heating the hydrogen and air at the combustion chamber inlet.

[0008] Furthermore, in the stable operating condition, air passes sequentially through a compressor and a first splitter. A portion of the outflowing air is heated by a third heat exchanger and then fed into the cathode of the solid oxide fuel cell. Simultaneously, hydrogen from the first hydrogen cylinder is heated by a fifth heat exchanger and enters the anode of the solid oxide fuel cell, where the hydrogen and air undergo a chemical reaction. The other portion of air flowing out of the first splitter is depressurized by a pressure reducing valve and then through a second splitter. A portion of the air directly enters the combustion chamber for cooling, while the other portion exchanges heat with the cathode exhaust gas in the first heat exchanger. Both then enter the combustion chamber after passing through the second heat exchanger. The anode exhaust gas exchanges heat with the hydrogen from the second hydrogen cylinder in the fourth heat exchanger, and then passes together through the sixth heat exchanger before entering the combustion chamber. The exhaust gas after combustion in the combustion chamber is discharged after being powered by the turbine. The turbine exhaust gas passes through the fifth and third heat exchangers in sequence to heat the hydrogen from the anode and the air from the cathode of the solid oxide fuel cell.

[0009] Furthermore, the pressure reducing valve is used to reduce the air pressure entering the second distributor to ensure that the exhaust gas from the solid oxide fuel cell can smoothly enter the combustion chamber.

[0010] Furthermore, the second splitter divides the air into two paths: one path directly enters the combustion chamber for cooling, and the other path is heated by the first heat exchanger and the second heat exchanger before being used for combustion.

[0011] Furthermore, in the first and second heat exchangers, under startup conditions, the pressurized air from the second hydrogen cylinder exchanges heat with the turbine exhaust only through the second heat exchanger; under stable operating conditions, the high-pressure air replenishment exchanges heat with the cathode exhaust of the solid oxide fuel cell only through the first heat exchanger.

[0012] Furthermore, the third splitter switches the flow direction of the turbine exhaust according to the operating conditions, and is used for preheating the combustion chamber intake or the solid oxide fuel cell intake.

[0013] Furthermore, in the start-up condition, hydrogen gas exchanges heat with the turbine exhaust gas only through the sixth heat exchanger; in the stable operation condition, the combustion chamber make-up hydrogen gas exchanges heat with the anode exhaust gas of the solid oxide fuel cell only through the fourth heat exchanger.

[0014] The beneficial effects of this invention are: 1. This invention constructs a solid oxide fuel cell / gas turbine coupled system as a power generation system. By innovatively integrating gas turbine turbocharging technology and hydrogen fuel solid oxide fuel cell, it achieves a dual breakthrough of energy cascade utilization and zero carbon emissions, reduces system heat loss, and improves exhaust gas utilization rate. Compared with ordinary gas turbine systems, it improves the system's energy utilization efficiency.

[0015] 2. Under the premise of achieving a systematic and efficient energy conversion goal, this invention couples a solid oxide fuel cell with a gas turbine system, allowing for flexible and adjustable energy distribution, enabling the system to operate under various conditions. 3. This invention designs two operating conditions: startup and stable operation. In the startup condition, the turbine drives the generator to generate electricity to provide power for the preheating of the solid oxide fuel cell reaction, and a regenerative cycle is added during the operation of the gas turbine. In the stable operation condition, the waste heat from the turbine exhaust is used to preheat the hydrogen and air at the inlet of the solid oxide fuel cell, achieving efficient energy integration. 4. The system of this invention uses hydrogen as the sole fuel and generates electricity through the electrochemical reaction of a solid oxide fuel cell and the work done by a turbine. It achieves zero carbon emissions throughout its entire life cycle under conditions without carbon capture, breaking through the dependence of traditional gas turbines on fossil fuels. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0017] In the diagram, 1-compressor, 2-first distributor, 3-pressure reducing valve, 4-second distributor, 5-first heat exchanger, 6-second heat exchanger, 7-combustion chamber, 8-turbine, 9-generator, 10-third heat exchanger, 11-solid oxide fuel cell (SOFC), 12-fourth heat exchanger, 13-fifth heat exchanger, 14-DC-AC converter, 15-sixth heat exchanger, 16-third distributor, 17-first hydrogen cylinder, 18-second hydrogen cylinder. Detailed Implementation

[0018] Combination Figure 1This embodiment describes a hydrogen fuel cell SOFC combined cycle power generation system based on gas turbine pressurization, comprising a compressor 1, a first splitter 2, a pressure reducing valve 3, a second splitter 4, a first heat exchanger 5, a second heat exchanger 6, a combustion chamber 7, a turbine 8, a generator 9, a third heat exchanger 10, a solid oxide fuel cell 11, a fourth heat exchanger 12, a fifth heat exchanger 13, a DC-AC converter 14, a sixth heat exchanger 15, a third splitter 16, a first hydrogen cylinder 17, and a second hydrogen cylinder 18. The compressor 1's outlet is connected to the inlet of the first distributor 2. One outlet of the first distributor 2 is connected to the pressure reducing valve 3, and the other outlet is connected to the cold-side inlet of the third heat exchanger 10. The pressure reducing valve 3's outlet is connected to the inlet of the second distributor 4. One outlet of the second distributor 4 is connected to the cooling air inlet of the combustion chamber 7; the other outlet is sequentially connected to the cold side of the first heat exchanger 5 and the second heat exchanger 6, and then connected to the combustion air inlet of the combustion chamber 7. The combustion chamber 7's outlet is connected to the inlet of the turbine 8. The turbine 8... The turbine 8 is coaxially connected to the compressor 1 and drives the generator 9; the outlet of the turbine 8 is connected to the inlet of the third splitter 16; the third splitter 16, under startup conditions, is sequentially connected to the hot-side inlet of the sixth heat exchanger 15 and the hot-side inlet of the second heat exchanger 6; the third splitter 16, under stable operation conditions, is sequentially connected to the hot-side inlet of the fifth heat exchanger 13 and the hot-side inlet of the third heat exchanger 10; the outlet of the second hydrogen cylinder 18 is sequentially connected to the hydrogen inlets of the fourth heat exchanger 12 and the sixth heat exchanger 15 before entering the combustion chamber 7; The outlet of the first hydrogen cylinder 17 is connected to the cold-side inlet of the fifth heat exchanger 13; the cold-side outlet of the fifth heat exchanger 13 is connected to the anode inlet of the solid oxide fuel cell 11; the power output terminal of the solid oxide fuel cell 11 is connected to the DC-AC converter 14; the cathode outlet of the solid oxide fuel cell 11 is connected to the first heat exchanger 5; the cathode inlet of the solid oxide fuel cell 11 is connected to the hot-side outlet of the third heat exchanger 10; and the anode outlet of the solid oxide fuel cell 11 is connected to the fourth heat exchanger 12.

[0019] This embodiment proposes a combined cycle power generation system for hydrogen fuel cell (SOFC) based on gas turbine pressurization, including start-up and stable operation conditions. During system startup, the solid oxide fuel cell 11 has not yet reached its operating temperature. In this startup condition, air is compressed by compressor 1 and then passes sequentially through the first splitter 2 and pressure reducing valve 3. At this time, pressure reducing valve 3 is not working, and the air is split into two paths by the second splitter 4. One part of the air directly enters the combustion chamber 7 for cooling; the other part passes through the first heat exchanger 5 and is heated by the second heat exchanger 6 before entering the combustion chamber 7. Simultaneously, hydrogen from the second hydrogen cylinder 18 passes through the fourth heat exchanger 12 and is heated by the sixth heat exchanger 15 before entering the combustion chamber 7. The hydrogen and air combust in the combustion chamber 7. The exhaust gas from the combustion chamber 7 enters the turbine 8 to perform work, driving the generator 9 to provide electrical energy for preheating the solid oxide fuel cell 11 before reaction. The exhaust gas from the turbine 8 passes through the third splitter 16, sequentially through the sixth heat exchanger 15 and the second heat exchanger 6, and is then discharged, heating the hydrogen and air at the inlet of the combustion chamber 7.

[0020] Once the solid oxide fuel cell 11 reaches its operating temperature, the system switches to a stable operating mode. Under stable operating conditions, air passes sequentially through compressor 1 and the first splitter 2. A portion of the outflowing air is heated by the third heat exchanger 10 and then fed into the cathode of the solid oxide fuel cell 11. Simultaneously, hydrogen from the first hydrogen cylinder 17 is heated by the fifth heat exchanger 13 and enters the anode of the solid oxide fuel cell 11, where the hydrogen and air undergo a chemical reaction. The remaining air from the first splitter 2 is depressurized by the pressure reducing valve 3 and then passed through the second splitter. 4. Part of the air directly enters the combustion chamber 7 for cooling, while the other part of the air exchanges heat with the cathode exhaust gas in the first heat exchanger 5. After passing through the second heat exchanger 6, both enter the combustion chamber 7. The anode exhaust gas exchanges heat with the hydrogen from the second hydrogen cylinder 18 in the fourth heat exchanger 12, and then passes through the sixth heat exchanger 15 before entering the combustion chamber 7. The exhaust gas after combustion in the combustion chamber 7 is discharged after being powered by the turbine 8. The exhaust gas from the turbine 8 passes through the fifth heat exchanger 13 and the third heat exchanger 10 in sequence to heat the hydrogen from the anode and the air from the cathode of the solid oxide fuel cell 11.

[0021] The pressure reducing valve 3 is used to reduce the air intake pressure because the air leading to the combustion chamber is the main intake air. The gas pressure in the fuel cell is slightly lost during the electrochemical reaction process, and the exhaust pressure is slightly lower than the intake pressure. In order to ensure that the SOFC exhaust can be smoothly retained in the combustion chamber, the pressure reducing valve is used to reduce the air intake pressure.

[0022] The second splitter 4 divides the air into two paths: one path goes directly into the combustion chamber 7 for cooling, and the other path is heated by the first heat exchanger 5 and the second heat exchanger 6 before being used for combustion.

[0023] In the start-up condition, the pressurized air from the second hydrogen cylinder 18 exchanges heat only with the exhaust gas from the turbine 8 through the second heat exchanger 6; in the stable operation condition, the high-pressure air replenishment exchanges heat only with the exhaust gas from the cathode of the solid oxide fuel cell 11 through the first heat exchanger 5.

[0024] The third splitter 16 switches the direction of turbine exhaust flow according to the operating conditions, and is used for preheating combustion chamber intake or solid oxide fuel cell 11 intake.

[0025] During startup, hydrogen gas exchanges heat with turbine exhaust gas only through the sixth heat exchanger 15. During stable operation, the combustion chamber make-up hydrogen gas exchanges heat with the anode exhaust gas of the solid oxide fuel cell 11 only through the fourth heat exchanger 12.

[0026] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A hydrogen fuelled SOFC actual combined cycle power generation system based on gas turbine supercharging, characterized by, The compressor (1), the first flow divider (2), the pressure reducing valve (3), the second flow divider (4), the first heat exchanger (5), the second heat exchanger (6), the combustion chamber (7), the turbine (8), the generator (9), the third heat exchanger (10), the solid oxide fuel cell (11), the fourth heat exchanger (12), the fifth heat exchanger (13), the direct current alternating current converter (14), the sixth heat exchanger (15), the third flow divider (16), the first hydrogen cylinder (17) and the second hydrogen cylinder (18); The outlet of the compressor (1) is connected to the inlet of the first flow divider (2), one outlet of the first flow divider (2) is connected to the pressure reducing valve (3), and the other outlet is connected to the cold side inlet of the third heat exchanger (10); the outlet of the pressure reducing valve (3) is connected to the inlet of the second flow divider (4), one outlet of the second flow divider (4) is connected to the cooling air inlet of the combustion chamber (7); the other outlet is connected to the cold side of the first heat exchanger (5) and the second heat exchanger (6) in turn, and then connected to the combustion air inlet of the combustion chamber (7); the outlet of the combustion chamber (7) is connected to the inlet of the turbine (8); the turbine (8) is coaxially connected to the compressor (1) and drives the generator (9); the outlet of the turbine (8) is connected to the inlet of the third flow divider (16); The third flow divider (16) is connected to the hot side inlet of the sixth heat exchanger (15) and the hot side inlet of the second heat exchanger (6) in turn under the starting condition; the third flow divider (16) is connected to the hot side inlet of the fifth heat exchanger (13) and the hot side inlet of the third heat exchanger (10) in turn under the stable running condition; The outlet of the second hydrogen cylinder (18) is connected to the hydrogen inlet of the fourth heat exchanger (12) and the sixth heat exchanger (15) in turn, and then connected to the combustion chamber (7); the outlet of the first hydrogen cylinder (17) is connected to the cold side inlet of the fifth heat exchanger (13); the cold side outlet of the fifth heat exchanger (13) is connected to the anode inlet of the solid oxide fuel cell (11); The power output end of the solid oxide fuel cell (11) is connected to the direct current alternating current converter (14); the cathode outlet of the solid oxide fuel cell (11) is connected to the first heat exchanger (5), and the cathode inlet of the solid oxide fuel cell (11) is connected to the hot side outlet of the third heat exchanger (10); the anode outlet of the solid oxide fuel cell (11) is connected to the fourth heat exchanger (12).

2. A hydrogen-fueled SOFC actual combined cycle power generation system based on gas turbine supercharging according to claim 1, characterized by, Under the starting condition, the air compressed by the compressor (1) passes through the first flow divider (2) and the pressure reducing valve (3) in turn, at this time the pressure reducing valve (3) does not work, and is divided into two parts in the second flow divider (4), one part of the air directly enters the combustion chamber (7) to play a cooling role; the other part of the air passes through the first heat exchanger (5) and then is heated in the second heat exchanger (6) before entering the combustion chamber (7); at the same time, the hydrogen from the second hydrogen cylinder (18) passes through the fourth heat exchanger (12) and is heated in the sixth heat exchanger (15) before entering the combustion chamber (7), and the hydrogen and the air are combusted in the combustion chamber (7); The exhaust gas of the combustion chamber (7) enters the turbine (8) to do work, driving the generator (9) to provide power for the solid oxide fuel cell (11) to heat up before reaction; The exhaust gas of the turbine (8) passes through the third flow divider (16) and then through the sixth heat exchanger (15) and the second heat exchanger (6) in sequence before being discharged, thereby heating the hydrogen and air entering the combustion chamber (7).

3. A hydrogen-fueled SOFC-based actual combined cycle power generation system supercharged by a gas turbine according to claim 1, characterized by, In the stable operation condition, the air passes through the compressor (1) and the first flow divider (2) in sequence, a part of the air flowing out is heated by the third heat exchanger (10) and then enters the cathode of the solid oxide fuel cell (11), while the hydrogen from the first hydrogen cylinder (17) is heated by the fifth heat exchanger (13) and then enters the anode of the solid oxide fuel cell (11), and the hydrogen and the air react chemically in the solid oxide fuel cell (11); another part of the air flowing out of the first flow divider (2) passes through the pressure reducing valve (3) and the second flow divider (4) in sequence, a part of the air directly enters the combustion chamber (7) to cool, and another part of the air exchanges heat with the cathode exhaust gas in the first heat exchanger (5), and then enters the combustion chamber (7) after passing through the second heat exchanger (6); The anode exhaust gas exchanges heat with the hydrogen from the second hydrogen cylinder (18) in the fourth heat exchanger (12), and then enters the combustion chamber (7) together after passing through the sixth heat exchanger (15); the exhaust gas of the combustion chamber (7) after combustion is discharged after doing work through the turbine (8), and the exhaust gas of the turbine (8) passes through the fifth heat exchanger (13) and the third heat exchanger (10) in sequence, thereby heating the hydrogen entering the anode of the solid oxide fuel cell (11) and the air entering the cathode of the solid oxide fuel cell (11).

4. A hydrogen-fueled SOFC-based actual combined cycle power generation system supercharged by a gas turbine according to claim 1, characterized by, The pressure reducing valve (3) is used to reduce the pressure of the air entering the second flow divider (4) to ensure that the exhaust gas of the solid oxide fuel cell (11) can smoothly enter the combustion chamber (7).

5. A hydrogen-fueled SOFC-based actual combined cycle power generation system supercharged by a gas turbine according to claim 1, characterized by, The second flow divider (4) divides the air into two paths, one of which directly enters the combustion chamber (7) for cooling, and the other of which is heated by the first heat exchanger (5) and the second heat exchanger (6) and then used for combustion.

6. A hydrogen-fueled SOFC-based actual combined cycle power generation system supercharged by a gas turbine according to claim 1, characterized by, The first heat exchanger (5) and the second heat exchanger (6) are used for heat exchange between the air from the second hydrogen cylinder (18) and the exhaust gas of the turbine (8) in the starting condition, and for heat exchange between the high-pressure air supplement and the exhaust gas of the cathode of the solid oxide fuel cell (11) in the stable operation condition.

7. A hydrogen-fueled SOFC-based actual combined cycle power generation system supercharged by a gas turbine according to claim 1, characterized by, The third flow divider (16) switches the flow direction of the turbine exhaust gas according to the working condition, and is used for preheating the combustion chamber inlet gas or the solid oxide fuel cell (11) inlet gas.

8. A hydrogen-fueled SOFC-based actual combined cycle power generation system supercharged by a gas turbine according to claim 1, characterized by, The fourth heat exchanger (12) and the sixth heat exchanger (15) are used for heat exchange between the hydrogen and the exhaust gas of the turbine in the starting condition, and for heat exchange between the hydrogen supplement of the combustion chamber and the exhaust gas of the anode of the solid oxide fuel cell (11) in the stable operation condition.

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