Gas turbine TCA / FGH large temperature difference driven S-CO2 power cycle system

Abstract

The invention discloses a gas turbine TCA / FGH large temperature difference driven S-CO2 power cycle system which comprises a gas compressor, a combustion chamber, a gas turbine, a TCA heat exchanger, an FGH heat exchanger, an S-CO2 compressor and an S-CO2 turbine, a hot side inlet and outlet of the TCA heat exchanger is connected with a hot air pipeline, the cold side of the TCA heat exchanger is connected with an S-CO2 working medium circulating device, the hot side of the FGH heat exchanger is connected with the S-CO2 working medium circulating device, and the hot side of the FGH heat exchanger is connected with the S-CO2 working medium circulating device. The cold side of the TCA heat exchanger is connected with a cold natural gas pipeline, the hot side of the TCA heat exchanger absorbs heat of high-temperature air, the air temperature is reduced to a set value, meanwhile, supercritical carbon dioxide after pressure boosting is heated, an S-CO2 turbine is pushed to do work, and natural gas is heated to the set temperature in the FGH heat exchanger. The TCA / FGH temperature difference condition is utilized, the S-CO2 power cycle is driven to output extra electric energy, the peak regulation capacity of the unit is improved, and meanwhile the problem of TCA / FGH heat imbalance is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy power cycle control, and in particular to an S-CO2 power cycle system driven by a gas turbine TCA / FGH with a large temperature difference. Background Art

[0002] In order to achieve higher efficiency and thermal performance, the turbine inlet temperature (TIT) of gas turbines is constantly increasing. At present, the TIT of F-class and H-class gas turbines is usually as high as about 1500℃. To a large extent, the turbine inlet temperature is limited by the high temperature strength of the turbine components. Advanced cooling technology is essential to improve the TIT of gas turbines, ensure the safe and reliable operation of gas turbines, and extend their service life.

[0003] At present, the cooling air for the turbine moving parts of the gas turbine can be extracted from the middle stage of the compressor, and after heat exchange with the external cooling medium through the turbine rotor cooling air cooling system (TCA system), it is sent to the turbine moving blades and rotors for cooling. The cooling medium absorbs heat and heats up, and is used to heat the natural gas to a certain temperature before sending it to the gas turbine combustion chamber, realizing the cascade utilization of energy. This is the fuel heater heat exchange system (FGH system).

[0004] There is often an energy imbalance between the gas turbine TCA system and the FGH system. For example, in the Mitsubishi M701F3 gas turbine system, the TCA air cooling load is about 11,300kW, and the FGH natural gas heating load is about 5,600kW. There is an energy imbalance between the two, and the energy quality is very different. The original design of the system uses an axial flow fan to pass the ambient air through the TCA and FGH in sequence. The medium air at the heat exchange outlet on the FGH side still has about 160℃ waste heat that has not been utilized, and the heat released to the air exceeds 5,300kW, which not only causes energy waste, but also generates thermal pollution to the environment. Summary of the invention

[0005] In order to overcome the defects and shortcomings of the prior art, the present invention provides a S-CO2 power cycle system driven by a gas turbine TCA / FGH with a large temperature difference, which can achieve cascade and efficient utilization of energy and improve the economic efficiency of the unit operation.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a S-CO2 power cycle system driven by a gas turbine TCA / FGH with a large temperature difference, comprising: a combined cycle topping cycle gas turbine unit, a TCA heat exchanger of the gas turbine, an FGH heat exchanger and an S-CO2 working medium circulation device;

[0008] The combined cycle topping cycle gas turbine unit includes a compressor, a combustion chamber, a gas turbine, a first generator, and a second generator;

[0009] The S-CO2 working medium circulation device includes an S-CO2 compressor and an S-CO2 turbine;

[0010] The hot side inlet of the TCA heat exchanger is connected to the compressor, the hot side outlet of the TCA heat exchanger is connected to the gas turbine, the outlet of the compressor is connected to the combustion chamber, the cold side inlet of the TCA heat exchanger is connected to the outlet of the S-CO2 compressor, and the cold side outlet of the TCA heat exchanger is connected to the inlet of the S-CO2 turbine;

[0011] The hot side inlet of the FGH heat exchanger is connected to the outlet of the S-CO2 turbine, the hot side outlet of the FGH heat exchanger is connected to the inlet of the S-CO2 compressor, the cold side inlet and outlet of the FGH heat exchanger are connected to the natural gas pipeline, and the cold side outlet of the FGH heat exchanger is also connected to the combustion chamber;

[0012] The hot side of the TCA heat exchanger absorbs the heat of the compressor outlet exhaust, reduces the air temperature to the set value, and sends it to the cooling gas turbine. At the same time, it heats the supercritical carbon dioxide that has been pressurized by the S-CO2 compressor, drives the S-CO2 turbine to work, drives the second generator to output electrical energy, and the FGH heat exchanger heats the natural gas to the set temperature;

[0013] The combustion chamber obtains the compressor outlet air and the hot natural gas from the cold side outlet of the FGH heat exchanger, and the mixed combustion produces fuel gas which is sent to the gas turbine to do work, thereby driving the first generator to output electrical energy.

[0014] As a preferred technical solution, the hot side inlet of the TCA heat exchanger is connected to a hot air pipeline provided with a first three-way valve, and a parallel pipeline provided with a first flow control valve;

[0015] The first three-way valve is used to divide the compressor outlet air into two paths, one path enters the hot side inlet of the TCA heat exchanger, and the other path enters the parallel pipeline equipped with a first flow control valve. The two air flows merge at the hot side outlet of the TCA heat exchanger and the pipeline equipped with a first pressure sensor and a first temperature sensor is provided. After merging, the air is sent to the gas turbine moving blades and rotor for cooling. The first pressure sensor and the first temperature sensor are respectively used to detect the pressure and temperature of the air in the pipeline.

[0016] As a preferred technical solution, control valves are provided at the cold side inlet and outlet of the TCA heat exchanger to adjust the S-CO2 flow rate.

[0017] As a preferred technical solution, the cold side inlet of the FGH heat exchanger is connected to a natural gas pipeline provided with a second three-way valve and a parallel pipeline provided with a second flow control valve;

[0018] The second three-way valve is used to divide the cold natural gas into two paths, one path enters the cold side inlet of the FGH heat exchanger, and the other path enters the parallel pipeline equipped with a second flow control valve. The two paths of natural gas are mixed in the pipeline equipped with a second pressure sensor and a second temperature sensor at the cold side outlet of the FGH heat exchanger, and then sent to the combustion chamber after mixing;

[0019] The second pressure sensor and the second temperature sensor are used to detect the pressure and temperature of the natural gas in the pipeline respectively.

[0020] As a preferred technical solution, the hot side inlet and outlet of the FGH heat exchanger are both provided with control valves for adjusting the S-CO2 flow rate.

[0021] As a preferred technical solution, the S-CO2 working medium circulation device is also provided with a first CO2 gas storage tank, a second CO2 gas storage tank, a third CO2 gas storage tank, and a fourth CO2 gas storage tank;

[0022] The outlet of the S-CO2 turbine is connected to the hot side inlet of the FGH heat exchanger through the first CO2 gas storage tank;

[0023] The hot side outlet of the FGH heat exchanger is connected to the inlet of the S-CO2 compressor through the second CO2 gas storage tank;

[0024] The cold side outlet of the TCA heat exchanger is connected to the inlet of the S-CO2 turbine through the third CO2 gas storage tank;

[0025] The outlet of the S-CO2 compressor is connected to the cold side inlet of the TCA heat exchanger through the fourth CO2 gas storage tank.

[0026] As a preferred technical solution, a cooling water heat exchanger is provided between the second CO2 gas storage tank and the S-CO2 compressor to reduce the temperature of carbon dioxide at the outlet of the second CO2 gas storage tank.

[0027] As a preferred technical solution, the compressor is coaxially arranged with the gas turbine to drive the first generator to output electricity.

[0028] As a preferred technical solution, the S-CO2 turbine is coaxially arranged with the S-CO2 compressor to drive the second generator to output electricity.

[0029] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0030] (1) The S-CO2 working fluid circulation device of the present invention uses the exhaust gas of the compressor in the TCA heat exchanger as the heat source and the low-temperature natural gas in the FGH heat exchanger as the cold source. It drives the power cycle through the large temperature difference environment of TCA / FGH to generate additional electrical energy, thereby improving the peak-shaving capacity of the gas turbine unit and improving the operating economy of the unit.

[0031] (2) The present invention fully absorbs the heat of the gas turbine TCA heat exchanger and fully supplies the heat to the FGH heat exchanger, thereby realizing full utilization of the heat of the gas turbine TCA / FGH system, solving the problem of waste heat in the traditional TCA / FGH system driven by an axial flow fan and using ambient air as the medium, eliminating thermal pollution caused by insufficient utilization of waste heat, and achieving energy conservation and environmental protection.

[0032] (3) The present invention adopts a supercritical carbon dioxide power cycle with a compact structure, stable operation and low noise. The S-CO2 working medium circulation device has no phase change during the circulation process, strong heat transfer and fluidity, stable chemical properties, and a small number of valves, and there is no problem of working medium erosion equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the overall structure of the S-CO2 power cycle system driven by the gas turbine TCA / FGH with a large temperature difference of the present invention;

[0034] Figure 2 The figure is a schematic diagram of the implementation flow of the S-CO2 power cycle system driven by the gas turbine TCA / FGH with a large temperature difference according to the present invention.

[0035] Among them, 1-compressor, 2-combustion chamber, 3-gas turbine, 4-first generator, 5-TCA heat exchanger, 6-FGH heat exchanger, 7-S-CO2 turbine, 8-S-CO2 compressor, 9-second generator, 10-first CO2 gas storage tank, 11-second CO2 gas storage tank, 12-third CO2 gas storage tank, 13-fourth CO2 gas storage tank, 14-first three-way valve, 15-first flow control valve, 16-second three-way valve, 17-second flow control valve, 18-cooling water heat exchanger. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] Example

[0038] like Figure 1 As shown, this embodiment provides a S-CO2 power cycle system driven by a gas turbine TCA / FGH with a large temperature difference, including: a combined cycle topping cycle gas turbine unit, a TCA heat exchanger 5 of the gas turbine, a FGH heat exchanger 6 and a S-CO2 working medium circulation device;

[0039] In this embodiment, the TCA heat exchanger 5 is a counter-flow heat exchanger, the hot side of which can realize cooling air flow control, and the cold side can realize the absorption of the heat of the hot side compressor of the TCA system and the regulation of the turbine inlet cooling air temperature;

[0040] In this embodiment, the hot side of the FGH heat exchanger can realize the heat supply to the cold side of the FGH system and regulate the natural gas temperature at the inlet of the combustion chamber. The cold side of the FGH heat exchanger supplies the fuel required by the combustion chamber;

[0041] In this embodiment, the combined cycle top cycle gas turbine unit includes a compressor 1, a combustion chamber 2, a gas turbine 3, a first generator 4, and a second generator 9. After the compressor 1 pressurizes the inlet air, most of it is sent to the combustion chamber 2 to be mixed and burned with the natural gas heated by the FGH heat exchanger 6. A small part is extracted and cooled by the TCA heat exchanger 5 to cool the moving blades and rotor of the gas turbine 3 to reduce the temperature to ensure its safe and stable operation. The air and natural gas in the combustion chamber 2 are mixed and burned to generate high-temperature and high-pressure gas, which is sent to the gas turbine 3 to do work, driving the first generator 4 to output electrical energy to supply external users. The exhaust gas at the outlet of the gas turbine 3 still has a relatively high temperature, and passes through the corresponding pressure plates of the waste heat boiler in turn to generate steam, which drives the steam turbine to do work and generate electricity.

[0042] Among them, the hot side inlet and outlet of the TCA heat exchanger 5 are connected to the hot air pipeline, and the cold side is connected to the S-CO2 power cycle device. The hot side of the TCA heat exchanger 5 absorbs the exhaust heat of the compressor 1 outlet of the gas turbine, reduces the air temperature to the set value, and sends it to the cooling gas turbine 3. At the same time, it heats the supercritical carbon dioxide in the S-CO2 working medium circulation device that has been pressurized by the S-CO2 compressor 8, drives the S-CO2 turbine 7 to do work, and drives the second generator 9 to output additional electrical energy. The S-CO2 working medium at the outlet of the S-CO2 turbine 7 still has a relatively high temperature, and heats the natural gas to the set temperature in the FGH heat exchanger 6, and then sends it to the gas turbine combustion chamber 2.

[0043] In this embodiment, the hot side inlet of the TCA heat exchanger 5 is connected to the first three-way valve 14, and the hot side outlet of the TCA heat exchanger 5 is connected to a pipeline with temperature and pressure sensors. Specifically, the hot side working medium is the air extracted from the compressor 1, and the extracted air is divided into two parts by the first three-way valve 14 in the hot air pipeline, one part enters the hot side of the TCA heat exchanger 5, and the other part enters the parallel pipeline with the first flow control valve 15. The two air flows merge before entering the gas turbine, and then enter a single pipeline with a temperature and pressure monitor to monitor the cooling air parameters entering the gas turbine 3; the cold side working medium is S-CO2, and the cold side inlet and outlet are respectively provided with control valves, and the hot side cooling air parameters are regulated by adjusting the S-CO2 flow rate.

[0044] In this embodiment, the cold side inlet of the FGH heat exchanger 6 is connected to the second three-way valve 16, and the cold side outlet of the FGH heat exchanger 6 is connected to the pipeline with temperature and pressure sensors. Specifically, the cold side working medium is cold natural gas from the natural gas station, which is divided into two paths by the second three-way valve 16 before entering the FGH heat exchanger 6. One path enters the FGH heat exchanger 6 to absorb heat and heat up, and the other path enters the parallel pipeline with the second flow control valve 17. The two paths of natural gas converge before entering the combustion chamber 2. Temperature and pressure sensors are set on the natural gas transmission pipeline; the hot side working medium is S-CO2, and the hot side inlet and outlet are respectively provided with control valves, and the cold side natural gas parameters are changed by adjusting the S-CO2 flow rate.

[0045] In this embodiment, the heat exchange between the cold and hot fluids in the heat exchanger follows the heat balance equation, and the heat exchange amount of the heat exchanger is expressed as:

[0046]

[0047] The left side of the equation (1) represents the heat exchange on the cold side or hot side of the heat exchanger, and the right side of the equation and They represent the fluid flow rate on the hot side and the fluid flow rate on the cold side of the heat exchanger, respectively, and h hot,in and h hot,out are the inlet and outlet enthalpies of the hot side fluid, h cold,in and h cold,out They represent the inlet and outlet specific enthalpies of the cold side fluid respectively.

[0048] The heat transfer efficiency of the heat exchanger can be expressed as:

[0049]

[0050] Among them, the right side of formula (2) is T hot,in and T hot,out are the inlet and outlet temperatures of the hot side fluid, T cold,in and T cold,out represent the inlet and outlet temperatures of the cold side fluid, respectively.

[0051] The heat exchangers are all arranged in pure countercurrent flow, where the logarithmic mean temperature difference and heat exchange area are:

[0052]

[0053] Where U is the heat transfer coefficient.

[0054] In this embodiment, the S-CO2 working medium circulation device includes an S-CO2 compressor 8, an S-CO2 turbine 7, a first CO2 gas storage tank 10, a second CO2 gas storage tank 11, a third CO2 gas storage tank 12, and a fourth CO2 gas storage tank 13;

[0055] Among them, the outlet of the S-CO2 compressor 8 is connected to the cold side inlet of the TCA heat exchanger 5 through the fourth CO2 gas storage tank 13, the cold side outlet of the TCA heat exchanger 5 is connected to the inlet of the S-CO2 turbine 7 through the third CO2 gas storage tank 12, the outlet of the S-CO2 turbine 7 is connected to the hot side inlet of the FGH heat exchanger 6 through the first CO2 gas storage tank 10, and the hot side outlet of the FGH heat exchanger 6 is connected to the inlet of the S-CO2 compressor 8 through the second CO2 gas storage tank 11, forming a closed-loop system.

[0056] In this embodiment, the S-CO2 working medium circulation process of the S-CO2 working medium circulation device is as follows: the high-pressure supercritical carbon dioxide coming out of the S-CO2 compressor 8 after compression absorbs the compressor exhaust cooling heat in the TCA heat exchanger 5, and after the temperature is increased, it enters the S-CO2 turbine 7 to do work, driving the generator 9 to output additional electricity. The hot end difference of the TCA heat exchanger is set to 10-20°C to ensure that it has a higher temperature when entering the S-CO2 turbine 7, thereby improving the working capacity of the working medium. The supercritical carbon dioxide coming out of the S-CO2 turbine 7 enters the FGH heat exchanger 6, heats the cold natural gas to the required temperature, and is finally sent to the inlet of the S-CO2 compressor.

[0057] In the S-CO2 working fluid cycle, the isentropic efficiency of the S-CO2 turbine and the S-CO2 compressor is defined as:

[0058]

[0059] Among them, h in represents the turbine inlet specific enthalpy, h out is the turbine outlet specific enthalpy, h out,s represents the constant entropy specific enthalpy.

[0060] Based on the isentropic efficiency, the compressor input power and turbine output power are expressed as:

[0061]

[0062] In the formula, and Respectively represent the flow rates through the compressor and turbine.

[0063] The first CO2 gas storage tank 10, the second CO2 gas storage tank 11, the third CO2 gas storage tank 12, and the fourth CO2 gas storage tank 13 can realize the CO2 flow control in the closed-loop system to meet the heat absorption of the TCA heat exchanger and the heat supply of the FGH heat exchanger, while storing energy;

[0064] Specifically, the first CO2 gas storage tank 10 stores the S-CO2 after work, and the first CO2 gas storage tank 10 can control the flow of S-CO2 entering the FGH heat exchanger 6 through the outlet flow regulating valve to achieve real-time adjustment of the natural gas temperature;

[0065] The second CO2 gas storage tank 11 stores the S-CO2 after heat release by the FGH heat exchanger. The outlet of the second CO2 gas storage tank 11 is connected to the inlet of the S-CO2 compressor 8. The second CO2 gas storage tank 11 can adjust the flow rate entering the S-CO2 compressor 8 to prevent the S-CO2 compressor 8 from surging.

[0066] The third CO2 gas storage tank 12 stores S-CO2 after absorbing the heat of the compressor extraction. The high-temperature and high-pressure air stored in the third CO2 gas storage tank 12 can be released during the peak period of electricity consumption, driving the S-CO2 turbine 7 to generate more electricity and improving the peak-shaving capacity of the unit;

[0067] The fourth CO2 gas storage tank 13 stores S-CO2 pressurized by the compressor. When the cooling air temperature and flow rate required by the gas turbine change, the fourth CO2 gas storage tank 13 can control the S-CO2 flow rate entering the TCA heat exchanger 5 through the outlet flow regulating valve, thereby realizing real-time adjustment of the cooling air temperature at the hot side outlet of the TCA heat exchanger 5.

[0068] In this embodiment, a cooling water heat exchanger 18 is provided between the second CO2 gas storage tank 11 and the S-CO2 compressor 8 to reduce the temperature of carbon dioxide at the outlet of the second CO2 gas storage tank.

[0069] In this embodiment, the compressor 1 is coaxially arranged with the gas turbine 3 to drive the first generator 4 to output electricity.

[0070] In this embodiment, the S-CO2 turbine 7 and the S-CO2 compressor 8 are coaxially arranged to drive the second generator 9 to output electricity.

[0071] like Figure 2 As shown, the implementation process of the S-CO2 power cycle system driven by the gas turbine TCA / FGH with a large temperature difference in this embodiment is as follows:

[0072] The S-CO2 working fluid cycle is constructed as a closed system, so the flow rate flowing through each device in the system is the same. The parameters of the hot side of TCA heat exchanger 5 and the cold side of FGH heat exchanger 6 are collected, and the hot end difference of TCA heat exchanger 5 is set. The inlet temperature (TIT) of S-CO2 turbine 7 must be high. Similarly, the hot end difference of FGH heat exchanger 6 is set to determine the S-CO2 temperature entering the hot side inlet of FGH heat exchanger 6. Then, the inlet pressure and outlet pressure of the circulating S-CO2 compressor 8, as well as the isentropic efficiency of S-CO2 compressor 8 and S-CO2 turbine 7 are set to calculate the exhaust temperature of S-CO2 turbine 7.

[0073] Furthermore, assuming the circulation flow, the cold side inlet temperature of TCA heat exchanger 5 and the hot side outlet temperature of FGH heat exchanger 6 can be obtained according to the heat balance, and the following judgments can be made: 1. Whether the cold end difference of TCA heat exchanger 5 is greater than 0; 2. Whether the cold end difference of FGH heat exchanger 6 is greater than 0; 3. Whether there is no node in TCA heat exchanger and FGH heat exchanger. If satisfied, then the outlet temperature of S-CO2 compressor 8 is obtained according to the heat balance of the recuperator, and then the inlet temperature of S-CO2 compressor 8 is obtained. That is, the cycle parameter analysis is completed, the work and efficiency are analyzed, and then the parameter optimization is performed.

[0074] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A S-CO2 power cycle system driven by a gas turbine TCA / FGH with a large temperature difference, characterized in that: include: Combined cycle topping cycle gas turbine units, gas turbine TCA heat exchangers, FGH heat exchangers and S-CO2 working fluid circulation devices; The combined cycle topping cycle gas turbine unit includes a compressor, a combustion chamber, a gas turbine, a first generator, and a second generator; The S-CO2 working medium circulation device includes an S-CO2 compressor and an S-CO2 turbine; The hot side inlet of the TCA heat exchanger is connected to the compressor, the hot side outlet of the TCA heat exchanger is connected to the gas turbine, the outlet of the compressor is connected to the combustion chamber, the cold side inlet of the TCA heat exchanger is connected to the outlet of the S-CO2 compressor, and the cold side outlet of the TCA heat exchanger is connected to the inlet of the S-CO2 turbine; The hot side inlet of the FGH heat exchanger is connected to the outlet of the S-CO2 turbine, the hot side outlet of the FGH heat exchanger is connected to the inlet of the S-CO2 compressor, the cold side inlet and outlet of the FGH heat exchanger are connected to the natural gas pipeline, and the cold side outlet of the FGH heat exchanger is also connected to the combustion chamber; The hot side of the TCA heat exchanger absorbs the heat of the compressor outlet exhaust, reduces the air temperature to the set value, and sends it to the cooling gas turbine. At the same time, it heats the supercritical carbon dioxide that has been pressurized by the S-CO2 compressor, drives the S-CO2 turbine to work, drives the second generator to output electrical energy, and the FGH heat exchanger heats the natural gas to the set temperature; The combustion chamber obtains the compressor outlet air and the hot natural gas from the cold side outlet of the FGH heat exchanger, and the mixed combustion produces fuel gas which is sent to the gas turbine to do work, thereby driving the first generator to output electrical energy.

2. The S-CO2 power cycle system driven by a large temperature difference of a gas turbine TCA / FGH according to claim 1 is characterized in that: The hot side inlet of the TCA heat exchanger is connected to a hot air pipeline provided with a first three-way valve and a parallel pipeline provided with a first flow control valve; The first three-way valve is used to divide the compressor outlet air into two paths, one path enters the hot side inlet of the TCA heat exchanger, and the other path enters the parallel pipeline equipped with a first flow control valve. The two air flows merge at the hot side outlet of the TCA heat exchanger and the pipeline equipped with a first pressure sensor and a first temperature sensor is provided. After merging, the air is sent to the gas turbine moving blades and rotor for cooling. The first pressure sensor and the first temperature sensor are respectively used to detect the pressure and temperature of the air in the pipeline.

3. The S-CO2 power cycle system driven by a large temperature difference of a gas turbine TCA / FGH according to claim 1 is characterized in that: The cold side inlet and outlet of the TCA heat exchanger are equipped with control valves to adjust the S-CO2 flow rate.

4. The S-CO2 power cycle system driven by a gas turbine TCA / FGH with a large temperature difference according to claim 1, characterized in that: The cold side inlet of the FGH heat exchanger is connected to a natural gas pipeline provided with a second three-way valve and a parallel pipeline provided with a second flow control valve; The second three-way valve is used to divide the cold natural gas into two paths, one path enters the cold side inlet of the FGH heat exchanger, and the other path enters the parallel pipeline equipped with a second flow control valve. The two paths of natural gas are mixed in the pipeline equipped with a second pressure sensor and a second temperature sensor at the cold side outlet of the FGH heat exchanger, and then sent to the combustion chamber after mixing; The second pressure sensor and the second temperature sensor are used to detect the pressure and temperature of the natural gas in the pipeline respectively.

5. The S-CO2 power cycle system driven by a gas turbine TCA / FGH with a large temperature difference according to claim 1, characterized in that: The hot side inlet and outlet of the FGH heat exchanger are both provided with control valves for adjusting the S-CO2 flow rate.

6. The S-CO2 power cycle system driven by a gas turbine TCA / FGH with a large temperature difference according to claim 1, characterized in that: The S-CO2 working medium circulation device is also provided with a first CO2 gas storage tank, a second CO2 gas storage tank, a third CO2 gas storage tank, and a fourth CO2 gas storage tank; The outlet of the S-CO2 turbine is connected to the hot side inlet of the FGH heat exchanger through the first CO2 gas storage tank; The hot side outlet of the FGH heat exchanger is connected to the inlet of the S-CO2 compressor through the second CO2 gas storage tank; The cold side outlet of the TCA heat exchanger is connected to the inlet of the S-CO2 turbine through the third CO2 gas storage tank; The outlet of the S-CO2 compressor is connected to the cold side inlet of the TCA heat exchanger through the fourth CO2 gas storage tank.

7. The S-CO2 power cycle system driven by a gas turbine TCA / FGH with a large temperature difference according to claim 1, characterized in that: A cooling water heat exchanger is provided between the second CO2 gas storage tank and the S-CO2 compressor to reduce the temperature of carbon dioxide at the outlet of the second CO2 gas storage tank.

8. The S-CO2 power cycle system driven by a gas turbine TCA / FGH with a large temperature difference according to claim 1, characterized in that: The compressor is coaxially arranged with the gas turbine to drive the first generator to output electrical power.

9. The S-CO2 power cycle system driven by a gas turbine TCA / FGH with a large temperature difference according to claim 1, characterized in that: The S-CO2 turbine is coaxially arranged with the S-CO2 compressor to drive the second generator to output electricity.

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