A sofc-allam coupled zero-carbon emission power cycle system

Abstract

The application provides a SOFC-Allam coupled zero-carbon emission power cycle system, and belongs to the technical field of power cycle systems. The application at least partially solves the problems that the existing SOFC tail gas often contains incompletely utilized fuel, and the tail gas still contains a large amount of residual heat due to the high working temperature of the SOFC, which leads to low overall energy utilization rate of the SOFC and great influence of tail gas emission on the environment. The application comprises a working medium pretreatment unit, a fuel reforming unit, a solid oxide fuel cell and a tail gas energy recovery unit. The fuel reforming unit is connected with the working medium pretreatment unit. The tail gas energy recovery unit comprises a combustion device, a turbine and a turbine exhaust unit. The application uses turbine exhaust to heat the working medium through a preheater, improves the working medium temperature, and further improves the system efficiency. The heat energy of the turbine exhaust is recycled in multiple stages. The incompletely consumed fuel in the anode of the fuel cell is completely combusted in the burner, thereby avoiding fuel waste.

Description

Technical Field

[0001] This invention belongs to the field of power cycle system technology, specifically relating to a zero-carbon emission power cycle system coupled with SOFC-Allam. Background Technology

[0002] Solid oxide fuel cells (SOFCs) are widely considered to be one of the most promising power sources due to their advantages such as high energy conversion efficiency, wide fuel applicability, all-solid state, and no need for catalysts containing precious metals.

[0003] However, SOFC exhaust gas often contains unused fuel, and due to the high operating temperature of SOFC, its exhaust gas still contains a large amount of residual heat, resulting in low overall energy utilization of SOFC and a significant impact of exhaust gas emissions on the environment. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art, and to provide a zero-carbon emission power cycle system with SOFC-Allam coupling.

[0005] This invention provides a zero-carbon emission power cycle system coupled with SOFC-Allam, the system comprising a working fluid pretreatment unit, a fuel reforming unit, a solid oxide fuel cell, and an exhaust gas energy recovery unit, wherein... The fuel reforming unit is connected to the working fluid pretreatment unit via a working fluid delivery channel to receive the working fluid that has been pressurized and preheated by the working fluid pretreatment unit and to reform the fuel within the fuel reforming unit. One electrode of the solid oxide fuel cell is connected to the fuel reforming unit to receive reformed fuel; the other electrode of the solid oxide fuel cell is connected to the pure oxygen output port of the working fluid pretreatment unit through a delivery channel to receive pure oxygen; the reformed fuel and the pure oxygen undergo an electrochemical reaction in the solid oxide fuel cell. The exhaust gas energy recovery unit includes a combustion device connected to the solid oxide fuel cell, a turbine, and a turbine exhaust unit capable of conveying the turbine exhaust. The turbine exhaust unit includes: The first exhaust assembly is connected to the fuel reforming unit and is capable of delivering high-temperature turbine exhaust to the fuel reforming unit. The second exhaust assembly connects the fuel reforming unit and the working fluid pretreatment unit to deliver turbine exhaust gas from the fuel reforming unit to the working fluid pretreatment unit for heating.

[0006] Furthermore, the working fluid pretreatment unit includes a working fluid pump, an oxygen compressor, a methane compressor, and a water pump connected to the preheater for pressurizing and preheating carbon dioxide, pure oxygen, methane, and water through the preheater.

[0007] Furthermore, the preheater includes a carbon dioxide outlet for conveying carbon dioxide, an oxygen outlet for conveying oxygen, a methane outlet for conveying methane, and a water outlet for conveying water, with two carbon dioxide outlets provided.

[0008] Specifically, the fuel reforming unit is a reforming reactor, which is connected to the methane outlet and water outlet of the preheater through a conveying channel, so as to reform methane and water into carbon dioxide and hydrogen under the action of a catalyst.

[0009] Specifically, the combustion device is a burner, which is connected to the solid oxide fuel cell so that the exhaust gas of the solid oxide fuel cell can be burned in the burner. The burner is connected to one of the carbon dioxide outlets of the preheater so that the carbon dioxide can be mixed with the combustion products in the burner to generate a high-temperature working fluid.

[0010] Preferably, the turbine is connected to another carbon dioxide outlet of the preheater for receiving carbon dioxide to cool the blades within the turbine, and the turbine is connected to a generator for driving the generator to generate electricity.

[0011] Specifically, the system also includes a carbon dioxide capture unit, which includes a first condenser for separating water vapor from turbine exhaust, a compressor connected to the first condenser and capable of pressurizing the turbine exhaust, and a second condenser capable of condensing and liquefying the turbine exhaust.

[0012] Furthermore, the turbine exhaust unit also includes a third exhaust assembly, which connects the preheater and the first condenser to deliver turbine exhaust from the preheater to the first condenser.

[0013] Furthermore, the carbon dioxide capture unit also includes a carbon dioxide storage tank connected to a second condenser for storing liquefied carbon dioxide.

[0014] Specifically, the working fluid pump is a carbon dioxide working fluid pump, which is connected to the second condenser for conveying liquefied carbon dioxide working fluid.

[0015] The beneficial effects of this invention are as follows: The preheater uses turbine exhaust to heat carbon dioxide, methane, pure oxygen, and water, increasing the temperature of these working fluids entering the power system and improving system efficiency. Unreacted fuel (H2) and pure oxygen in the fuel cell exhaust are combusted in a carbon dioxide atmosphere within the burner. Because pure oxygen is used as the oxidant, the power cycle system proposed in this invention produces no NOx. The high-temperature, high-pressure working fluid generated by combustion enters the turbine to drive the generator and produce electricity. The thermal energy of the turbine exhaust (high-temperature CO2) is recovered and utilized in multiple stages. Unconsumed fuel (H2) at the fuel cell anode is completely combusted in the burner, avoiding fuel waste. The burner uses preheated CO2 to regulate the combustion temperature and as the working fluid to participate in the turbine's work. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structural connection of a SOFC-Allam coupled zero-carbon emission power cycle system according to the present invention; Among them, 1 is the working fluid pump, 2 is the oxygen compressor, 3 is the methane compressor, 4 is the water pump, 5 is the preheater, 6 is the reforming reactor, 7 is the solid oxide fuel cell, 8 is the burner, 9 is the turbine, 10 is the generator, 11 is the first condenser, 12 is the compressor, 13 is the second condenser, and 14 is the carbon dioxide storage tank. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] The Allam cycle mentioned in this application is a novel Brayton cycle that uses supercritical CO2 as the working fluid and directly heats the working fluid by burning gaseous fuel and pure oxygen in a burner.

[0019] like Figure 1 As shown in the figure, a specific embodiment of the present invention provides a zero-carbon emission power cycle system coupled with an SOFC-Allam fuel cell. The system includes a working fluid pretreatment unit, a fuel reforming unit, a solid oxide fuel cell 7, and an exhaust gas energy recovery unit. The fuel reforming unit is connected to the working fluid pretreatment unit through the working fluid conveying channel. It is used to receive the working fluid that has been pressurized and preheated by the working fluid pretreatment unit and to reform the fuel in the fuel reforming unit. The anode of the solid oxide fuel cell 7 is connected to the fuel reforming unit to receive reformed fuel; the other electrode of the solid oxide fuel cell is connected to the pure oxygen output port of the working fluid pretreatment unit via a delivery channel to receive pure oxygen; the reformed fuel and pure oxygen undergo an electrochemical reaction in the solid oxide fuel cell, the reaction being: direct electrochemical oxidation of hydrogen (H2) (the dominant reaction), H2 losing electrons and oxygen ions (O²⁻) at the anode.- O₂ combines with H₂O to form H₂O, and the released electrons form an electric current through the external circuit. O₂ gains electrons at the cathode to form oxygen ions (O²⁻). - The ions migrate to the anode via an electrolyte (such as a YSZ oxygen ion conductor).

[0020] The anode of the solid oxide fuel cell 7 receives reformed fuel supplied by the fuel reforming unit. The reformed fuel is H2 and CO2 produced by the reaction of methane.

[0021] The exhaust gas energy recovery unit includes a combustion device connected to a solid oxide fuel cell 7, a turbine 9, and a turbine exhaust unit capable of delivering turbine exhaust gas; The turbine exhaust unit includes: The first exhaust assembly is connected to the fuel reforming unit and is able to deliver high-temperature turbine exhaust to the fuel reforming unit. The second exhaust assembly connects the fuel reforming unit and the working fluid pretreatment unit to deliver turbine exhaust gas from the fuel reforming unit to the working fluid pretreatment unit for heating.

[0022] A turbine is a power machine that converts the energy (mainly kinetic and pressure energy) of a fluid (liquid or gas) into mechanical rotational energy. It can be understood as a high-speed rotating impeller. When a fluid (such as steam, gas, water or wind) impacts or flows over the blades of this impeller at a certain speed and pressure, it will drive the impeller to rotate, thereby outputting mechanical work.

[0023] The core working principle of Turbo 9: High-pressure, high-speed fluid: The fluid (steam, gas, water, wind) has a high pressure and / or velocity before entering turbine 9.

[0024] Impact or reaction force: When the fluid flows through the nozzle (or stator vane) of turbine 9, the pressure decreases and the velocity increases, forming a high-speed jet. This high-speed jet impacts the moving blades mounted on the rotor, or the fluid expands and accelerates in the flow channel formed by the moving blades, generating a reaction force on the blades.

[0025] Rotational motion: Impact or reaction force drives the moving blades, causing the rotor of turbine 9 to rotate at high speed.

[0026] Energy output: The rotor's rotating shaft outputs mechanical work. This rotating shaft can directly drive generators to generate electricity, propellers (airplanes, ships), compressors, pumps, or other mechanical equipment.

[0027] In this embodiment, turbine 9 can be a gas turbine, using high-temperature, high-pressure gas as the working fluid. The gas is produced by the combustion of fuel with O2 in the burner.

[0028] Working principle: Unreacted O2 in a solid oxide fuel cell mixes and burns with unreacted fuel in the combustion chamber to produce high-temperature, high-pressure gas; the gas enters the turbine, expands, and does work, driving the rotor to rotate; the turbine output drives the load.

[0029] In this embodiment, the turbine exhaust gas in turbine 9 is first transported to the fuel reforming unit through the first exhaust assembly. At this time, the turbine exhaust gas with a higher temperature heats the fuel reforming unit. After that, the turbine exhaust gas with a lower temperature is transported from the fuel reforming unit to the preheater 5 in the working fluid pretreatment unit through the second exhaust assembly to heat the preheater 5.

[0030] Based on the above-mentioned basic technical solution of the present invention, the working fluid pretreatment unit includes a working fluid pump 1, an oxygen compressor 2, a methane compressor 3 and a water pump 4 connected to the preheater 5, for pressurizing and preheating carbon dioxide, pure oxygen, methane and water through the preheater 5. The preheater is connected to the working fluid pump 1, the oxygen compressor 2, the methane compressor 3 and the water pump 4. In the preheater 5, carbon dioxide, pure oxygen and water are preheated to the operating temperature.

[0031] In this embodiment, the operating temperature is not limited, as long as it meets the normal operating requirements of the system.

[0032] Furthermore, the preheater 5 includes a carbon dioxide outlet for conveying carbon dioxide, an oxygen outlet for conveying oxygen, a methane outlet for conveying methane, and a water outlet for conveying water. There are two carbon dioxide outlets, and heated methane and water are conveyed to the reforming reactor 6 through the methane outlet and the water outlet.

[0033] In this embodiment, the carbon dioxide outlet, oxygen outlet, methane outlet, and water outlet are all equipped with power components for transporting these working fluids, including but not limited to water pumps, fans, and other equipment.

[0034] Furthermore, the fuel reforming unit is a reforming reactor 6. The reforming reactor 6 is connected to the methane outlet and water outlet of the preheater 5 through a conveying channel, so that methane and water can be reformed into carbon dioxide and hydrogen under the action of a catalyst. The reforming reactor 6 is a key piece of equipment for producing syngas (mainly composed of carbon dioxide and hydrogen). The fuel reforming unit is heated by the turbine exhaust gas in the system, without the need for continuous external heating.

[0035] In this embodiment, the reforming of methane with water into carbon dioxide and hydrogen is essentially a coupling of steam methane reforming (SMR) and water-gas shift (WGS). When preheated methane (CH4) and water vapor (H2O) enter the catalyst bed of reforming reactor 6 through the conveying channel, the following reactions occur under high temperature and the action of the catalyst: Methane steam reforming reaction (main reaction, strongly endothermic) Principle: Methane molecules (CH4) crack on the surface of a catalyst (usually nickel-based) and react with water vapor to produce carbon monoxide (CO) and hydrogen (H2).

[0036] Requirements: High temperature (700–950℃) and catalyst-driven forward reaction (endothermic reaction requires continuous heating).

[0037] Water-gas shift reaction (side reaction, exothermic) Principle: The CO generated in the previous step reacts further with water vapor to be converted into carbon dioxide (CO2) and more hydrogen.

[0038] Function: To regulate the ratio of H2 and CO in the synthesis gas and to balance part of the heat demand using an exothermic reaction.

[0039] In a preferred embodiment, the combustion device is a burner 8, which is connected to a solid oxide fuel cell 7 so that the exhaust gas of the solid oxide fuel cell 7 can be burned in the burner 8. The burner 8 is connected to one of the carbon dioxide outlets of the preheater 5 so that the carbon dioxide can be mixed with the combustion products in the burner 8 to generate a high-temperature working fluid with a temperature of not less than 1300°C.

[0040] Furthermore, turbine 9 is connected to another carbon dioxide outlet to receive carbon dioxide to cool the blades inside turbine 9. Turbine 9 is connected to generator 10 to drive generator 10 to generate electricity. In this turbine 9, the power output of turbine 9 drives generator 10 to rotate, so that generator 10 generates electricity.

[0041] In a preferred embodiment, the system further includes a carbon dioxide capture unit, which comprises a first condenser 11 for separating water vapor from turbine exhaust, a compressor 12 connected to the first condenser 11 and capable of pressurizing the remaining turbine exhaust, and a second condenser 13 capable of condensing and liquefying the remaining turbine exhaust. The turbine exhaust enters the first condenser 11 and is cooled by cooling water, causing the water in the exhaust to condense into a liquid state, which flows out from the liquid outlet of the first condenser 11. The condensate splits into two streams: one stream is pressurized by the water pump 4 and re-enters the power cycle, while the other stream is discharged outside the system. After the water in the turbine exhaust condenses and flows out, the remaining turbine exhaust consists only of gaseous carbon dioxide. The remaining turbine exhaust then enters the compressor 12 to be compressed and pressurized. The compressed turbine exhaust then enters the second condenser 13 and condenses into liquid carbon dioxide by cooling water.

[0042] In a preferred embodiment, the turbine exhaust unit further includes a third exhaust assembly, which connects the preheater 5 and the first condenser 11 to deliver the turbine exhaust in the preheater 5 to the first condenser 11. The turbine exhaust discharged from the preheater 5 has been cooled to near room temperature and contains some water vapor, which is separated into water and gas in the first condenser 11.

[0043] In this specific embodiment, the carbon dioxide capture unit also includes a carbon dioxide storage tank 14, which is connected to the second condenser 13 for storing liquefied carbon dioxide. When the turbine exhaust gas is compressed and condensed into liquid carbon dioxide in the second condenser 13, the liquid carbon dioxide is divided into two streams. One stream enters the carbon dioxide storage tank 14 for storage, and the other stream enters the working fluid pump 1 to rejoin the power cycle.

[0044] Based on the above-mentioned basic technical solution of the present invention, the working fluid pump 1 is a carbon dioxide working fluid pump. The working fluid pump 1 is connected to the second condenser 13 for conveying liquid carbon dioxide working fluid. The liquid carbon dioxide is conveyed to the preheater 5 for pressurization and preheating through the working fluid pump 1.

[0045] One specific embodiment discloses a SOFC-Allam coupled zero-carbon emission power cycle system, including a working fluid pretreatment unit, a fuel reforming unit, a solid oxide fuel cell 7, and an exhaust gas energy recovery unit, wherein, The fuel reforming unit is connected to the working fluid pretreatment unit through the working fluid conveying channel. It is used to receive the working fluid that has been pressurized and preheated by the working fluid pretreatment unit and to reform the fuel in the fuel reforming unit. The anode of the solid oxide fuel cell 7 is connected to the fuel reforming unit to receive reformed fuel; the other electrode of the solid oxide fuel cell 7 is connected to the pure oxygen output port of the working fluid pretreatment unit through a delivery channel to receive pure oxygen; the reformed fuel and pure oxygen undergo an electrochemical reaction in the solid oxide fuel cell 7. The exhaust gas energy recovery unit includes a combustion device, a turbine 9, and a turbine exhaust unit; the combustion device is connected to the exhaust gas outlet of the solid oxide fuel cell 7; the turbine 9 is connected to the outlet of the combustion device to utilize the high temperature and high pressure generated by combustion to output mechanical work to the outside; the turbine 9 is connected to the turbine exhaust unit. The turbine exhaust unit includes: The first exhaust assembly is connected to the fuel reforming unit and is capable of supplying heat to the fuel reforming unit; The second exhaust assembly connects the fuel reforming unit and the working fluid pretreatment unit to deliver turbine exhaust gas from the fuel reforming unit to the working fluid pretreatment unit for heating. The working fluid pretreatment unit includes a working fluid pump 1, an oxygen compressor 2, a methane compressor 3, a water pump 4, and a preheater 5 connected in sequence to pressurize and preheat carbon dioxide, pure oxygen, methane, and water. The preheater 5 includes a carbon dioxide outlet for conveying carbon dioxide, an oxygen outlet for conveying oxygen, a methane outlet for conveying methane, and a water outlet for conveying water; two carbon dioxide outlets are provided. The fuel reforming unit is a reforming reactor 6, which is connected to the methane and water outlets of the preheater 5 via a conveying channel to reform methane and water into carbon dioxide and hydrogen under the action of a catalyst. The combustion device is a burner 8, which is connected to a solid oxide fuel cell 7 so that the exhaust gas from the solid oxide fuel cell 7 can be burned within the burner 8. The burner 8 is connected to one of the carbon dioxide outlets of the preheater 5 so that carbon dioxide can mix with the combustion products within the burner 8 to generate a high-temperature working fluid. A turbine 9... Internal energy is converted into mechanical energy. Turbine 9 is connected to another carbon dioxide outlet of preheater 5 to receive carbon dioxide to cool the blades inside turbine 9. Turbine 9 is connected to a generator to drive the generator to generate electricity. The system also includes a carbon dioxide capture unit, which includes a first condenser 11 for separating water vapor from turbine exhaust, a compressor 12 connected to the first condenser 11 and capable of pressurizing the remaining turbine exhaust, and a second condenser 13 capable of condensing and liquefying the remaining turbine exhaust. The turbine exhaust unit also includes a third exhaust assembly, which is connected to preheater 5 and the first condenser 11 to deliver turbine exhaust from preheater 5 to the first condenser 11. The carbon dioxide capture unit also includes a carbon dioxide storage tank 14, which is connected to the second condenser 13 to store liquefied carbon dioxide. The working fluid pump 1 is a carbon dioxide working fluid pump, which is connected to the second condenser 13 to deliver liquefied carbon dioxide working fluid.

[0046] In this embodiment, the system operation process is as follows: Carbon dioxide, pure oxygen, methane, and water are pumped to a certain pressure by working fluid pump 1, oxygen compressor 2, methane compressor 3, and water pump 4, respectively, and enter preheater 5. In preheater 5, carbon dioxide, pure oxygen, and water are preheated to a certain temperature. The heated methane and water enter reforming reactor 6, where a reforming reaction occurs under the action of a catalyst, reforming them into carbon dioxide and hydrogen. The carbon dioxide, hydrogen, and remaining water generated in the reforming reactor enter the anode of solid oxide fuel cell 7 and react electrochemically with pure oxygen entering the cathode of solid oxide fuel cell 7 to generate electricity. The exhaust gas of solid oxide fuel cell 7 contains hydrogen and oxygen that have not undergone electrochemical reaction, and then the exhaust gas of solid oxide fuel cell 7 enters burner 8 for combustion. The carbon dioxide working fluid flowing out of the preheater 5 outlet is divided into two streams: one stream enters burner 8 and mixes with combustion products to become a high-temperature working fluid, and the other stream enters the turbine as a cooling gas to cool the turbine blades. The high-temperature working fluid generated by combustion in burner 8 enters turbine 9, expands, and drives generator 10 to generate electricity. The turbine exhaust gas, having completed its work, enters reformer 6 through the first exhaust assembly to provide heat for the reforming reaction. After heat exchange in reformer 6, the turbine exhaust gas enters preheater through the second exhaust assembly to preheat the carbon dioxide, oxygen, methane, and water entering the power cycle. After heat exchange in preheater 5, the turbine exhaust gas temperature has dropped to near room temperature. Subsequently, the turbine exhaust gas enters the first condenser 11 through the third exhaust assembly, where it is cooled by cooling water. The water in the turbine exhaust gas is condensed into a liquid state and flows out from the liquid outlet of the first condenser 11. The condensate splits into two streams: one is pressurized by water pump 4 and re-enters the power cycle, while the other is discharged from the system. After the water in the turbine exhaust gas condenses and flows out, the remaining turbine exhaust gas consists only of gaseous carbon dioxide. The remaining turbine exhaust then enters compressor 12 where it is compressed to increase its pressure. The compressed turbine exhaust then enters the second condenser 13, where it is condensed into liquid carbon dioxide by the action of cooling water. Subsequently, the liquid carbon dioxide splits into two streams: one stream enters carbon dioxide storage tank 14 for storage, and the other stream enters working fluid pump 1 to rejoin the power cycle.

[0047] In summary, the embodiments disclosed herein have at least the following technical effects: True zero carbon emissions: The system's core working fluid is carbon dioxide (CO2), which is recycled in a closed loop. The carbon in the fuel is ultimately completely captured and stored in liquid form in a CO2 storage tank, rather than being released into the atmosphere. Through the established CO2 capture unit, low-cost CO2 capture is achieved, resulting in net-zero CO2 emissions from fossil fuel utilization throughout the entire process.

[0048] Highly efficient energy cascade utilization: High-grade energy generation: Solid oxide fuel cells (SOFCs) directly and efficiently convert the chemical energy of fuel (reformed gas) into electrical energy, with high efficiency and no combustion loss.

[0049] Low-to-medium grade energy recovery: The unreacted exhaust gas (including H2, CO, etc.) of the fuel cell is completely burned in the burner, releasing energy to generate high-temperature and high-pressure working fluid to drive the turbine to generate electricity.

[0050] The thermal energy from turbine exhaust (high-temperature CO2) is recovered and utilized in multiple stages: firstly, it provides the necessary reaction heat to the fuel reforming unit (reformer reactor). Secondly, it provides heat to the working fluid pretreatment unit (preheater), preheating the new working fluids (CO2, O2, CH4, H2O) entering the cycle. This cascaded utilization of energy significantly improves the overall energy utilization efficiency of the system.

[0051] Improved fuel utilization: Fuel (H2, CO) that is not fully consumed at the anode of the fuel cell is completely burned in the burner, avoiding fuel waste.

[0052] Highly efficient thermal integration and self-balancing: Turbine exhaust gas serves as the main heat source, providing heat to the reforming reactor and preheater in sequence. The reforming reactor is heated by turbine exhaust gas, eliminating the need for an additional heat source and reducing the complexity of system thermal management and energy consumption.

[0053] Water resource recycling: Some of the water generated by the system (electrochemical reaction products, condensate from turbine exhaust) is separated and recycled. The recycled water is pressurized by a water pump and reinjected into the circulation system as a source of steam for the reforming reaction, reducing the consumption of fresh water and wastewater discharge.

[0054] Efficient recycling and utilization of working fluid (CO2): CO2 is not only the primary circulating working fluid, but also plays multiple roles: as a coolant for turbine blades, protecting the turbine; as a diluent in the burner, controlling combustion temperature and constituting the working fluid; and it is efficiently liquefied, separated, and stored in the carbon dioxide capture unit. Most of the liquefied CO2 is pumped back into the cycle for reuse, while a small portion is stored as a product.

[0055] The system boasts high integration and a compact structure: it tightly couples high-efficiency SOFC power generation, efficient heat-work conversion and energy recovery from the Allam cycle (supercritical CO2 cycle), fuel reforming, and carbon capture technology into a single system. Through meticulous thermal integration (turbine exhaust heating) and material circulation (CO2, H2O), it reduces the need for external interfaces and auxiliary equipment.

[0056] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A zero-carbon emission power cycle system coupled with SOFC-Allam, characterized in that, The system includes a working fluid pretreatment unit, a fuel reforming unit, a solid oxide fuel cell, and a tail gas energy recovery unit, wherein... The fuel reforming unit is connected to the working fluid pretreatment unit via a working fluid delivery channel to receive the working fluid that has been pressurized and preheated by the working fluid pretreatment unit and to reform the fuel within the fuel reforming unit. One electrode of the solid oxide fuel cell is connected to the fuel reforming unit to receive reformed fuel; the other electrode of the solid oxide fuel cell is connected to the pure oxygen output port of the working fluid pretreatment unit through a delivery channel to receive pure oxygen; the reformed fuel and the pure oxygen undergo an electrochemical reaction in the solid oxide fuel cell. The exhaust gas energy recovery unit includes a combustion device connected to the solid oxide fuel cell, a turbine, and a turbine exhaust unit capable of conveying the turbine exhaust. The turbine exhaust unit includes: The first exhaust assembly is connected to the fuel reforming unit and is capable of delivering high-temperature turbine exhaust to the fuel reforming unit. The second exhaust assembly connects the fuel reforming unit and the working fluid pretreatment unit to deliver turbine exhaust gas from the fuel reforming unit to the working fluid pretreatment unit for heating.

2. The SOFC-Allam coupled zero-carbon emission power cycle system according to claim 1, characterized in that, The working fluid pretreatment unit includes a working fluid pump, an oxygen compressor, a methane compressor, and a water pump connected to the preheater for pressurizing and preheating carbon dioxide, pure oxygen, methane, and water through the preheater.

3. The SOFC-Allam coupled zero-carbon emission power cycle system according to claim 2, characterized in that, The preheater includes a carbon dioxide outlet for conveying carbon dioxide, an oxygen outlet for conveying oxygen, a methane outlet for conveying methane, and a water outlet for conveying water, with two carbon dioxide outlets provided.

4. The SOFC-Allam coupled zero-carbon emission power cycle system according to claim 3, characterized in that, The fuel reforming unit is a reforming reactor, which is connected to the methane outlet and water outlet of the preheater through a conveying channel, so that methane and water can be reformed into carbon dioxide and hydrogen under the action of a catalyst.

5. The SOFC-Allam coupled zero-carbon emission power cycle system according to claim 3, characterized in that, The combustion device is a burner, which is connected to the solid oxide fuel cell so that the exhaust gas of the solid oxide fuel cell can be burned in the burner. The burner is connected to one of the carbon dioxide outlets of the preheater so that the carbon dioxide can be mixed with the combustion products in the burner to generate a high-temperature working fluid.

6. The SOFC-Allam coupled zero-carbon emission power cycle system according to claim 3, characterized in that, The turbine is connected to another carbon dioxide outlet of the preheater to receive carbon dioxide to cool the blades inside the turbine, and the turbine is connected to a generator to drive the generator to generate electricity.

7. The SOFC-Allam coupled zero-carbon emission power cycle system according to claim 1, characterized in that, The system also includes a carbon dioxide capture unit, which includes a first condenser for separating water vapor from turbine exhaust, a compressor connected to the first condenser and capable of pressurizing the turbine exhaust, and a second condenser capable of condensing and liquefying the turbine exhaust.

8. The SOFC-Allam coupled zero-carbon emission power cycle system according to claim 7, characterized in that, The turbine exhaust unit further includes a third exhaust assembly, which connects the preheater and the first condenser to deliver turbine exhaust from the preheater to the first condenser.

9. The SOFC-Allam coupled zero-carbon emission power cycle system according to claim 7, characterized in that, The carbon dioxide capture unit also includes a carbon dioxide storage tank, which is connected to the second condenser for storing liquefied carbon dioxide.

10. The SOFC-Allam coupled zero-carbon emission power cycle system according to claim 7, characterized in that, The working fluid pump is a carbon dioxide working fluid pump, which is connected to the second condenser for conveying liquefied carbon dioxide working fluid.

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