A S-CO2 power cycle system driven by a gas turbine TCA / FGH with a large temperature difference

Abstract

The present invention discloses a S-CO2 power cycle system driven by a TCA / FGH gas turbine with a large temperature difference. The system includes a compressor, a combustion chamber, a gas turbine, a TCA heat exchanger, an FGH heat exchanger, an S-CO2 compressor, and an S-CO2 turbine. The hot side inlet and outlet of the TCA heat exchanger are connected to a hot air pipeline, and the cold side is connected to an S-CO2 working medium circulation device. The hot side of the FGH heat exchanger is connected to the S-CO2 working medium circulation device, and the cold side is connected to a cold natural gas pipeline. The hot side of the TCA heat exchanger absorbs heat from the high-temperature air, reducing the air temperature to a set value, while simultaneously heating the pressurized supercritical carbon dioxide, driving the S-CO2 turbine to perform work, and heating the natural gas to a set temperature in the FGH heat exchanger. The present invention utilizes the TCA / FGH temperature difference to drive the S-CO2 power cycle to output additional electricity, improving the unit's peak-shaving capability and simultaneously solving the TCA / FGH heat imbalance problem.

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] To achieve higher efficiency and thermal performance, gas turbine turbine inlet temperatures (TIT) are constantly increasing. Currently, the TIT of F-class and H-class gas turbines is typically around 1500°C. This temperature is largely limited by the high-temperature strength of the turbine components. Advanced cooling technologies are crucial for increasing gas turbine TIT, ensuring safe and reliable operation, and extending the service life of gas turbines.

[0003] Currently, cooling air for gas turbine moving parts is extracted from the compressor's intermediate stages. After passing through the turbine rotor cooling air system (TCA system), it exchanges heat with an external coolant before being fed into the turbine blades and rotor for cooling. The coolant absorbs heat and heats up, which is then used to heat natural gas to a desired temperature before being fed into the gas turbine combustion chamber, achieving cascaded energy utilization. This is known as the fuel heater heat exchange system (FGH system).

[0004] Gas turbine TCA systems and FGH systems often experience an energy imbalance. For example, in a Mitsubishi M701F3 gas turbine system, the TCA air cooling load is approximately 11,300kW, while the FGH natural gas heating load is approximately 5,600kW. This creates an energy imbalance and a significant difference in energy quality. The original system design used axial fans to sequentially pass ambient air through the TCA and FGH. The FGH heat exchange outlet still contained unused waste heat of approximately 160°C, dissipating over 5,300kW of heat to the air. This not only resulted in energy waste but also generated thermal pollution to the environment. Summary of the Invention

[0005] In order to overcome the defects and shortcomings of the existing technology, the present invention provides a S-CO2 power cycle system driven by a large temperature difference of a gas turbine TCA / FGH, 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 exhaust gas from the compressor outlet, 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 electricity, 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 burns the mixed gas to produce gas which is sent to the gas turbine to perform 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 entering the hot side inlet of the TCA heat exchanger, and the other path entering the parallel pipeline equipped with a first flow control valve. The two air flows converge in the pipeline equipped with a first pressure sensor and a first temperature sensor at the hot side outlet of the TCA heat exchanger. After merging, the two air flows are sent to the gas turbine moving blades and rotor for cooling. The first pressure sensor and the first temperature sensor are used to detect the pressure and temperature of the air in the pipeline, respectively.

[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 entering the cold side inlet of the FGH heat exchanger, and the other path entering 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 further 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 S-CO2 turbine inlet 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 and the gas turbine are coaxially arranged to drive the first generator to output electricity.

[0028] As a preferred technical solution, the S-CO2 turbine and the S-CO2 compressor are coaxially arranged 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 from the compressor of the TCA heat exchanger as the heat source and the low-temperature natural gas of 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 electricity, 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 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 waste 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 saving energy and protecting the environment.

[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, has high heat transfer and fluidity, and is chemically stable. The number of valves used is small, and there is no problem of working medium corroding the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0034] Figure 2 This 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 of 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 solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to 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 intended to limit the present invention.

[0037] Example

[0038] like Figure 1 As shown, this embodiment provides a gas turbine TCA / FGH large temperature difference driven S-CO2 power cycle system, including: a combined cycle topping cycle gas turbine unit, a TCA heat exchanger 5 of the gas turbine, an FGH heat exchanger 6 and an 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 heat absorption of the hot side compressor exhaust of the TCA system and control 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, a combined cycle topping 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. The compressor 1 pressurizes inlet air and feeds most of it into the combustion chamber 2 for combustion with natural gas heated by an FGH heat exchanger 6. A small amount of air is extracted and cooled by a TCA heat exchanger 5 to cool the blades and rotor of the gas turbine 3, lowering the temperature and ensuring safe and stable operation. The air and natural gas in the combustion chamber 2 mix and burn to produce high-temperature, high-pressure gas, which is fed into the gas turbine 3 to generate power, driving the first generator 4 to output electrical energy for external users. The exhaust gas at the outlet of the gas turbine 3, still at a relatively high temperature, passes through the corresponding pressure plates of the waste heat boiler in sequence to generate steam, which drives the steam turbine to generate power.

[0042] 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 heat of the exhaust air at the outlet of the gas turbine compressor 1, 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 after being pressurized by the S-CO2 compressor 8, drives the S-CO2 turbine 7 to perform work, and drives the second generator 9 to output additional electricity. The S-CO2 working medium at the outlet of the S-CO2 turbine 7 still has a relatively high temperature. It heats the natural gas to the set temperature in the FGH heat exchanger 6 and is then sent 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 by the compressor 1. 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 parameters of the cooling air entering the gas turbine 3. The cold side working medium is S-CO2, and the cold side inlet and outlet are respectively equipped with control valves. The hot side cooling air parameters are controlled 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 a pipeline with temperature and pressure sensors. Specifically, the cold-side working medium is cold natural gas from a natural gas station. Before entering the FGH heat exchanger 6, it is divided into two paths by the second three-way valve 16. One path enters the FGH heat exchanger 6 to absorb heat and increase temperature, and the other path enters a parallel pipeline with a second flow control valve 17. The two paths of natural gas converge before entering the combustion chamber 2. Temperature and pressure sensors are installed on the natural gas transmission pipeline. The hot-side working medium is S-CO2. The hot-side inlet and outlet are respectively equipped with control valves. 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 capacity of the heat exchanger is expressed as:

[0046]

[0047] The left side of the equation (1) represents the heat transfer on the cold side or hot side of the heat exchanger, and the right side of the equation (1) represents the heat transfer on the cold side or hot side of the heat exchanger. 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, 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, T on the right side of formula (2) 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 discharged from the S-CO2 compressor 8 after compression absorbs the heat of the compressor exhaust cooling in the TCA heat exchanger 5, and after the temperature is increased, it enters the S-CO2 turbine 7 to perform work, driving the generator 9 to output additional electricity. The hot end differential of the TCA heat exchanger is set to 10-20°C to ensure a higher temperature when entering the S-CO2 turbine 7, thereby improving the working capacity of the working medium. The supercritical carbon dioxide discharged from the S-CO2 turbine 7 enters the FGH heat exchanger 6, heats the cold natural gas to the required temperature, and is finally fed into the inlet of the S-CO2 compressor.

[0057] In the S-CO2 working fluid cycle, the isentropic efficiency of the S-CO2 turbine and 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 and specific enthalpy.

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

[0061]

[0062] Where, and Represent the flow rates through the compressor and turbine respectively.

[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 peak power consumption periods to drive the S-CO2 turbine 7 to generate more electricity and improve the peak-shaving capacity of the unit.

[0067] The fourth CO2 gas storage tank 13 stores the 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 achieving 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 and the gas turbine 3 are coaxially arranged 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 the TCA heat exchanger 5 and the cold side of the FGH heat exchanger 6 are collected, and the hot end differential of the TCA heat exchanger 5 is set to ensure that the inlet temperature (TIT) of the S-CO2 turbine 7 is high. Similarly, the hot end differential of the FGH heat exchanger 6 is set to determine the S-CO2 temperature entering the hot side inlet of the FGH heat exchanger 6. Then, the inlet and outlet pressures of the circulating S-CO2 compressor 8, as well as the isentropic efficiencies of the S-CO2 compressor 8 and S-CO2 turbine 7 are set to calculate the exhaust temperature of the S-CO2 turbine 7.

[0073] Furthermore, assuming a given circulation flow rate, the cold-side inlet temperature of the TCA heat exchanger 5 and the hot-side outlet temperature of the FGH heat exchanger 6 can be calculated based on heat balance. The following criteria can be determined: 1. Is the cold-end differential of the TCA heat exchanger 5 greater than 0? 2. Is the cold-end differential of the FGH heat exchanger 6 greater than 0? 3. Does the TCA heat exchanger and FGH heat exchanger have nodes? If these conditions are met, the outlet temperature of the S-CO2 compressor 8 and, subsequently, the inlet temperature of the S-CO2 compressor 8 can be calculated based on the heat balance of the regenerative heat exchanger. This completes the cycle parameter analysis, analyzes the work and efficiency, and then proceeds to parameter optimization.

[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 considered as equivalent replacement methods and are included in the scope of protection 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 exhaust gas from the compressor outlet, 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 electricity, 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 burns the mixed gas to produce gas which is sent to the gas turbine to perform 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, 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 entering the hot side inlet of the TCA heat exchanger, and the other path entering the parallel pipeline equipped with a first flow control valve. The two air flows merge in the pipeline equipped with a first pressure sensor and a first temperature sensor at the hot side outlet of the TCA heat exchanger. After merging, they are sent to the gas turbine moving blades and rotor for cooling. The first pressure sensor and the first temperature sensor are used to detect the pressure and temperature of the air in the pipeline, respectively.

3. The S-CO2 power cycle system driven by a large temperature difference of a gas turbine TCA / FGH according to claim 1, 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 large temperature difference of a gas turbine TCA / FGH 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 entering the cold side inlet of the FGH heat exchanger, and the other path entering 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 large temperature difference of a gas turbine TCA / FGH 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 large temperature difference of a gas turbine TCA / FGH according to claim 1, characterized in that: The S-CO2 working medium circulation device is further 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 S-CO2 turbine inlet 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 large temperature difference of a gas turbine TCA / FGH 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 large temperature difference of a gas turbine TCA / FGH according to claim 1, characterized in that: The compressor is coaxially arranged with the gas turbine to drive the first generator to output electricity.

9. The S-CO2 power cycle system driven by a large temperature difference of a gas turbine TCA / FGH 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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