A multi-energy combined supply system for gas turbine cooling air

Abstract

The present invention belongs to the technical field of gas turbine cooling, and specifically relates to a multi-energy combined supply system for gas turbine cooling air. The system comprises a multi-energy combined supply system, a gas turbine system coupled via a transcritical Rankine cycle (TCA), and a transcritical Rankine cycle system. In the multi-energy combined supply system, cooling air is cooled by the TCA before entering the gas turbine. The medium in the transcritical Rankine cycle absorbs heat in the TCA and then enters the turbine for expansion and work. Cooling water outside the system absorbs heat in the condenser of the transcritical Rankine cycle, forming high-temperature water to heat the bromide cooling unit in the multi-energy combined supply system. The low-temperature water produced by the bromide cooling unit is atomized and mixed with the intake air of the air compressor to reduce the intake air temperature. This system not only improves the combined cycle power generation efficiency, but also achieves multi-energy combined supply and stable energy recovery for gas turbine cooling air, fundamentally ensuring the safe operation of the gas turbine cooling system.

Description

Technical Field

[0001] The present invention belongs to the technical field of gas turbine cooling, and in particular relates to a gas turbine cooling air multi-energy co-supply system based on a transcritical Rankine cycle. Background Art

[0002] The combined cycle gas turbine (CCPP) is mainly composed of three parts: gas turbine (mainly including air compressor, combustion chamber, and gas turbine), waste heat boiler, and steam turbine. It is widely used in power generation systems in my country's metallurgical and natural gas industries.

[0003] like Figure 1 The diagram shows a schematic diagram of a conventional CCPP gas turbine cooling air system. The CCPP system consists of an air compressor 11, a combustion chamber 12, a gas turbine 13, a waste heat boiler 14, and a steam turbine 15, all connected in sequence. Compressed air generated by the air compressor 11 enters the combustion chamber 12, where it mixes with blast furnace gas or natural gas for combustion. The combustion products drive the gas turbine 13. The exhaust gas from the gas turbine 13 is then recycled through the waste heat boiler 14, and the resulting steam enters the steam turbine 15 to generate power. A portion of the cooling air generated by the air compressor 11 is pre-extracted and sent to the TCA 30, where it recovers heat from boiler condensate or high-pressure feedwater before being sent to the gas turbine 13 to assist in cooling key components. Thanks to advanced gas turbine cooling technology, the most advanced H-class gas turbines can achieve a turbine inlet temperature of up to 1600°C, with combined cycle efficiencies exceeding 64%.

[0004] The turbine air cooler (TCA) is a key component of the gas turbine cooling system. Currently, many low-calorific-value gas units (such as the MHI M251S and M701S) and natural gas units (MHI M701F4), including the most advanced H-class gas turbines (such as the MHI M701J), in China utilize an external TCA to further cool extracted compressor air (with a temperature range of 350°C to 500°C and a flow rate that can account for 10% to 20% of the total intake air) before it is delivered to the turbine. This process also recovers waste heat from this compressed air and returns it to the boiler condensate or boiler feed water, thereby improving the efficiency and output of the entire CCPP unit. This turbine cooling method not only enhances cooling efficiency but also avoids energy waste, thereby enhancing the unit's economic efficiency.

[0005] However, TCAs are mostly air-water shell-and-tube heat exchangers, making zero leakage impossible. This is especially true when using high-pressure boiler feedwater, significantly increasing the safety risks to the gas turbine. Furthermore, issues such as vibration, vaporization, and leak monitoring complicate TCA operation and maintenance. Furthermore, existing TCAs utilize a single energy method, recovering only heat energy, which is then directly fed into the waste heat boiler (HRSG) system. Because the steam Rankine cycle is the base cycle of the CCPP, power generation efficiency is low (typically 20%-30%, depending on the HRSG steam parameters and system design), and energy utilization efficiency is also limited.

[0006] Therefore, the existing method for utilizing turbine cooling air energy does not conform to the principle of deep energy recovery, namely, "temperature matching and step-by-step utilization." Furthermore, the energy from the turbine cooling air is not recovered during cold startup and hot shutdown, resulting in significant energy waste. Finally, when the temperature of the upstream turbine cooling air fluctuates significantly and falls below normal, stable energy recovery becomes difficult.

[0007] Therefore, it is very necessary to provide a new heat recovery system to improve the energy recovery efficiency and operation safety of the gas turbine cooling system. Summary of the Invention

[0008] In order to solve the above technical problems, the present invention provides a gas turbine cooling air multi-energy co-supply and energy storage system.

[0009] The present invention adopts the following technical solutions:

[0010] A gas turbine cooling air multi-energy co-generation system includes a gas turbine combined cycle system, wherein the gas turbine combined cycle system includes an air compressor, a combustion chamber, a gas turbine, a waste heat boiler, and a steam turbine connected in sequence;

[0011] Also includes:

[0012] A transcritical Rankine cycle system, comprising a booster pump, a regenerator, a turbine, and a condenser connected in sequence to form a loop, wherein the gas turbine combined cycle system is coupled to the transcritical Rankine cycle system via a TCA, wherein the cooling air generated by the air compressor is further cooled by the TCA before entering the gas turbine, and the medium flowing out of the regenerator absorbs heat in the TCA before entering the turbine for expansion and work;

[0013] A multi-energy combined power supply system, which includes a bromide cooling unit and an atomization system connected in series, wherein the outlet of the atomization system is connected to the air inlet of the air compressor; the cooling water outside the system absorbs heat through the condenser to form high-temperature water, which flows into the bromide cooling unit and provides heat for it; the low-temperature water generated by the bromide cooling unit enters the atomization system to generate micro-mist cold water particles, which are mixed with the intake air of the air compressor to reduce the intake air temperature.

[0014] Preferably, in the transcritical Rankine cycle system, after the medium is expanded in the turbine, it first enters the regenerator to perform a heat exchange with the medium from the booster pump in the regenerator, and then enters the condenser to perform a secondary heat exchange with the cooling water outside the system.

[0015] Preferably, a heat storage system is further included, which includes a shell and tube heat exchanger, which is arranged on the main line between the air compressor and the TCA, the tube side of the shell and tube heat exchanger is connected to the main line, and the shell side of the shell and tube heat exchanger is filled with phase change energy storage material; the air compressor is also connected to the main line between the shell and tube heat exchanger and the TCA through a first branch, and the main line between the shell and tube heat exchanger and the TCA is also connected to the gas engine turbine through a second branch.

[0016] Preferably, a first regulating valve is provided on the main line between the air compressor and the shell and tube heat exchanger; a second regulating valve is provided on the first branch line, and a third regulating valve is provided on the second branch line.

[0017] Preferably, the operating states of the heat storage system and the transcritical Rankine cycle system are adjusted according to the supply and temperature of the gas turbine cooling air. Specifically, the following operations are performed according to the operating state of the gas turbine:

[0018] State 1: When the gas turbine operates normally and the cooling air temperature is above 350°C, the first and third regulating valves are closed, and the second regulating valve is opened. At this time, only the gas turbine combined cycle system and the transcritical Rankine cycle system are operating, and the cooling air directly enters the TCA for cooling.

[0019] State 2: When the gas turbine is in cold start or hot shutdown, the second regulating valve is closed, and the first and third regulating valves are opened. At this time, only the heat storage system and the gas turbine combined cycle system are in operation. The cooling air flows through the shell and tube heat exchanger and then enters the gas turbine. The shell and tube heat exchanger stores heat from the cooling air.

[0020] State 3: When the gas turbine operates normally and the cooling air temperature is lower than 350°C, the second and third regulating valves are closed and the first regulating valve is opened. At this time, the transcritical Rankine cycle system, the gas turbine combined cycle system, and the heat storage system are all in operation. The cooling air first passes through the shell and tube heat exchanger to absorb heat and then enters the heat exchanger TCA for cooling.

[0021] Preferably, the tube side of the shell-and-tube heat exchanger is also connected to a water supply pipeline. When the gas engine turbine is in state 1, the water supply pipeline transports ambient temperature water into the tube side of the shell-and-tube heat exchanger. The ambient temperature water absorbs the heat stored in the thermal storage system, is heated, and then supplies heat to the outside. Preferably, in a multi-energy combined power supply system, the high-temperature water and low-temperature water can also directly supply heat or cooling to the outside of the system.

[0022] Preferably, the transcritical Rankine cycle includes a transcritical organic Rankine cycle and a transcritical inorganic Rankine cycle.

[0023] Preferably, the turbine is also connected to a generator.

[0024] The beneficial effects of the present invention are:

[0025] (1) A transcritical Rankine cycle is used to recover the energy of the gas turbine cooling air. In this new energy recovery method, the TCA becomes a supercritical heater of the transcritical Rankine cycle. In this heat exchanger, since the working fluid is directly converted into a supercritical "gas" state, there is no traditional phase change process. Even if it leaks, it will not cause a safety accident to the gas turbine. Therefore, compared with the traditional water-cooled TCA, the "intrinsic safety" of the gas turbine cooling system is achieved, and auxiliary components such as leakage monitoring are no longer required, which greatly simplifies the equipment. In addition, the TCA can be replaced by a compact plate microchannel heat exchanger, which not only significantly improves the heat exchange efficiency but also greatly reduces the size of the equipment.

[0026] (2) High-efficiency recovery of gas turbine cooling air energy is achieved. Within the existing gas turbine cooling air temperature range (350°C-500°C), due to the low heat source temperature, the thermoelectric conversion efficiency is not high whether using the traditional steam Rankine cycle or the advanced supercritical Brayton cycle. The well-known subcritical Rankine cycle is generally suitable for recovering medium and low temperature waste heat (below 350°C) to generate electricity, and its efficiency is also not high. When the working fluid is in a supercritical state, it can operate at a higher heat source temperature and avoid phase change latent heat loss. The theoretical power generation efficiency of the transcritical Rankine cycle can exceed 30%. Therefore, by coupling the transcritical Rankine cycle, the thermoelectric conversion efficiency is improved compared to the current traditional CCPP bottom cycle.

[0027] (3) For the first time, the multi-energy cogeneration and cascade utilization of gas turbine cooling air was realized. Through the transcritical Rankine cycle, the heat of the high-temperature air is recovered on the supercritical side of the cycle for power generation. At the same time, the heat of the condenser is recovered on the subcritical side of the cycle to realize external heat supply (production of high-temperature hot water or steam). In addition, by utilizing the heat source provided by the cycle, the addition of a bromide cooling unit can also meet the cooling demand of the combined cycle power plant under high temperature conditions in summer or reduce the gas turbine inlet air temperature to further improve the power generation efficiency of the combined cycle unit. Therefore, this system realizes the deep recovery of gas turbine cooling air energy.

[0028] (4) This application adds an energy storage system that can achieve full-cycle stable recovery of the gas turbine cooling air energy. By adding an energy storage system, the gas turbine cooling air energy during the interval of several hours between the cold start and hot shutdown of the gas turbine can also be recovered and utilized. In addition, by coupling the transcritical Rankine cycle and energy storage, when the temperature of the upstream gas turbine cooling air is low, the continuous and stable operation of the transcritical Rankine cycle can be achieved to a certain extent, avoiding the booster pump reliability problem caused by frequent start and shutdown. The shell and tube heat exchanger is used in this energy storage system to meet the energy storage and release requirements, which is different from the traditional "container plus heat exchanger" storage / release design concept and greatly simplifies the system structure.

[0029] (5) The multi-energy combined supply and energy storage system for gas turbine cooling air based on the transcritical Rankine cycle proposed in this application has wide applicability. For example, for the blast furnace gas CCPP unit in a steel plant, the gas turbine cooling air temperature range is 350℃-400℃. In this case, a transcritical organic Rankine cycle with an organic working fluid can be selected to achieve energy recovery. For the natural gas CCPP unit in a natural gas power plant, the gas turbine cooling air temperature range is 400℃-500℃. In this case, a transcritical inorganic Rankine cycle with an inorganic working fluid can be selected to achieve energy recovery.

[0030] (6) The proposed transcritical Rankine cycle can drive the booster pump through the turbine of the transcritical Rankine cycle. The system can be integrated into a skid with a compact structure.

[0031] In summary, the multi-energy combined supply and energy storage system for gas turbine cooling air provided in this application can not only further improve the power generation efficiency of the combined cycle, but also realize the multi-energy combined supply of gas turbine cooling air and stable energy recovery throughout the entire cycle, and fundamentally ensure the safe operation of the gas turbine cooling system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the turbine cooling air system of an existing combined cycle unit.

[0033] Figure 2This is a schematic diagram of the multi-energy combined supply system for gas turbine cooling air based on the transcritical Rankine cycle of this application.

[0034] Figure 3 This is a schematic diagram of a heat storage system also provided in the gas turbine cooling air multi-energy cogeneration system based on the transcritical Rankine cycle of the present application.

[0035] The meanings of the symbols in the figure are as follows:

[0036] 11-air compressor, 12-combustion chamber, 13-gas turbine, 14-waste heat boiler, 15-steam turbine;

[0037] 21-boost pump, 22-regenerator, 23-turbine, 231-generator, 24-condenser;

[0038] 30-TCA;

[0039] 41-bromine refrigeration unit, 42-atomization system;

[0040] 51-shell and tube heat exchanger 52-water supply pipeline;

[0041] 61-main line, 611-first regulating valve, 62-first branch line, 621-second regulating valve, 63-second branch line, 631-third regulating valve. DETAILED DESCRIPTION

[0042] The technical solution of the present invention is described in more detail below with reference to the embodiments and drawings.

[0043] Example 1

[0044] like Figure 2 As shown, the present application provides a gas turbine cooling air multi-energy cogeneration system, which includes a gas turbine combined cycle system, a transcritical Rankine cycle system, and a multi-energy cogeneration system.

[0045] The gas turbine combined cycle system includes an air compressor 11, a combustion chamber 12, a gas turbine 13, a waste heat boiler 14, and a steam turbine 15, all connected in sequence. The transcritical Rankine cycle system includes a booster pump 21, a regenerator 22, a turbine 23, and a condenser 24, all connected in sequence to form a loop. The turbine 23 is connected to a generator 231 for external power supply. The multi-energy cogeneration system includes a cooling system and an atomization system 42 connected in series. The cooling system is a bromide refrigeration unit 41, and the outlet of the atomization system 42 is also connected to the air inlet of the air compressor 11.

[0046] The gas turbine combined cycle system and the transcritical Rankine cycle system are coupled via a TCA 30. Specifically, a TCA 30 is installed in the cooling air circuit between the air compressor 11 and the gas turbine 13. The cooling air generated by the air compressor 11 first enters the TCA 30 for cooling before returning to the gas turbine 13. The cold side of the TCA 30 is also located between the regenerator 22 and the turbine 23 in the transcritical Rankine cycle system. The medium flowing out of the regenerator 22 absorbs heat on the cold side of the TCA 30 before entering the turbine 23 for expansion and work. Furthermore, after expansion and work in the turbine 23, the medium first enters the hot side of the regenerator 22 for primary heat exchange with the medium from the boost pump 21 on the cold side of the regenerator 22, and then enters the hot side of the condenser 24 for secondary heat exchange with cooling water outside the system.

[0047] Therefore, the process of the transcritical Rankine cycle in this system is as follows: the low-temperature, low-pressure liquid working medium is pressurized to above its critical pressure in the booster pump 21, and then flows through the cold side of the regenerator 22 to be preheated into a medium-temperature, high-pressure liquid or supercritical state, and then enters the cold side of the TCA30 to further absorb the heat of the hot-side cooling air to a supercritical state, and then enters the turbine 23 to expand and work. The medium is reduced in pressure to below its critical pressure and becomes a medium-temperature, low-pressure gas, and then flows through the hot side of the regenerator 22 to be precooled into a low-temperature, low-pressure gas, and finally, releases heat on the hot side of the condenser 24 and is condensed into a low-temperature, low-pressure liquid, thus completing a cycle.

[0048] The cold side water inlet of the condenser 24 is connected to the normal temperature water outside the system. The normal temperature water absorbs heat through the condenser 24 to form high temperature water. The high temperature water flows into the bromide refrigeration unit 41 and provides heat for it. The low temperature water generated by the bromide refrigeration unit 41 enters the atomization system 42 to generate micro-mist cold water particles. The micro-mist cold water particles are mixed with the intake air of the air compressor 11 to reduce the intake air temperature, thereby improving the combined cycle power generation efficiency.

[0049] Furthermore, the high-temperature water and low-temperature water formed above can also directly provide heating or cooling to the outside of the system.

[0050] Furthermore, based on different operating conditions, the transcritical Rankine cycle can select a transcritical organic Rankine cycle or a transcritical inorganic Rankine cycle.

[0051] Example 2

[0052] like Figure 3 As shown, the system of this embodiment is the same as that of embodiment 1, except that a heat storage system is added.

[0053] The heat storage system includes a shell-and-tube heat exchanger 51, located on the main line 61 for conveying cooling air between the air compressor 11 and the TCA 30. The tube side of the shell-and-tube heat exchanger 51 is connected to the main line 61, and the shell side of the shell-and-tube heat exchanger 51 is filled with a phase-change energy storage material. This allows the shell-and-tube heat exchanger 51 to store and release energy. During energy storage, high-temperature cooling air flows through the tube side, causing the solid phase-change material to undergo a solid-to-liquid phase transition, absorbing heat from the cooling air within the tube side. During energy release, cooler cooling air flowing through the tube side absorbs heat from the liquid phase-change material in the shell side, causing the phase-change material to undergo a liquid-to-solid phase transition.

[0054] In order to achieve cascaded energy utilization, a first regulating valve 611 is provided on the main line between the air compressor 11 and the shell and tube heat exchanger 51. The air compressor 11 is also connected to the main line 61 between the shell and tube heat exchanger 51 and the TCA 30 through a first branch line 62, and a second regulating valve 621 is provided on the first branch line 62; the main line 61 between the shell and tube heat exchanger 51 and the TCA 30 is also connected to the gas turbine 13 through a second branch line 63, and a third regulating valve 631 is provided on the second branch line 63.

[0055] The operating states of the heat storage system and the transcritical Rankine cycle system can be adjusted according to the supply and temperature of the gas turbine cooling air. Specifically, the following operations are performed according to the operating state of the gas turbine 13:

[0056] State 1: When the gas turbine 13 is operating normally and the cooling air temperature is between 350°C and 500°C, the first regulating valve 611 and the third regulating valve 631 are closed, and the second regulating valve 621 is open. At this time, only the gas turbine combined cycle system and the transcritical Rankine cycle system are operating, and the cooling air directly enters the TCA 30 for cooling.

[0057] State 2: When the gas turbine 13 is in cold start or hot shutdown, the second regulating valve 621 is closed, and the first regulating valve 611 and the third regulating valve 631 are open. At this time, only the heat storage system and the gas turbine combined cycle system are in operation. The cooling air first passes through the tube side of the shell and tube heat exchanger 51 to release heat to the phase change material in the shell, and then is sent to the gas turbine 13. In other words, the shell and tube heat exchanger 51 stores heat from the cooling air.

[0058] State 3: When the gas turbine 13 is operating normally and the cooling air temperature is lower than 350°C, the second regulating valve 621 and the third regulating valve 631 are closed, and the first regulating valve 611 is opened. At this time, the transcritical Rankine cycle system, the gas turbine combined cycle system, and the heat storage system are all operating. The cooling air first absorbs heat through the shell and tube heat exchanger 51 and then enters the TCA 30 for cooling.

[0059] Furthermore, the tube side of the shell and tube heat exchanger 51 is also connected to the water supply pipeline 52. When the gas turbine 13 is in state 1, the water supply pipeline 52 transports normal temperature water into the tube side of the shell and tube heat exchanger 51. The normal temperature water absorbs the heat stored in the heat storage system and is heated to supply heat to the outside.

[0060] The adjustment method is explained below in combination with specific working conditions.

[0061] 1. State 1

[0062] When the gas turbine 13 operates normally and the cooling air temperature is between 350° C. and 500° C., the first regulating valve 611 and the third regulating valve 631 are closed, and the second regulating valve 621 is opened, and only the gas turbine combined cycle system and the transcritical Rankine cycle system operate.

[0063] (1) For the winter operation of the CCPP unit using blast furnace gas, a transcritical organic Rankine cycle is adopted, and the working fluid is siloxane. The system operation process is as follows: liquid siloxane at 30°C and 0.3 MPa is pressurized to 50°C and 3 MPa by the booster pump 21, and then flows through the cold side of the regenerator 22 to be preheated to a liquid state of 150°C and 2.9 MPa. It then enters the cold side of the TCA30 to further absorb the heat of the hot side cooling air to a supercritical state of 340°C and 2.8 MPa, and then enters the turbine 23 to expand and become a gaseous state of 180°C and 0.5 MPa. It then flows through the hot side of the regenerator 22 to be precooled to a gaseous state of 80°C and 0.4 MPa. Finally, it releases heat on the hot side of the condenser 24 and is condensed to a liquid state of 30°C and 0.3 MPa, thus completing a cycle. At the same time, the 350°C, 1.1MPa gas turbine cooling air is cooled to 160°C, 1.0MPa and then sent to the gas turbine 13. At this time, the 25°C normal temperature water is heated to 70°C and supplied to the outside.

[0064] (2) For the summer operation of the CCPP unit using blast furnace gas, a transcritical organic Rankine cycle is adopted, and the working fluid is siloxane. The system operation process is as follows: 30℃, 0.3MPa liquid siloxane is pressurized to 50℃, 3MPa by the booster pump 21, and then flows through the cold side of the regenerator 22 to be preheated to 150℃, 2.9MPa liquid, and then enters the cold side of the TCA30 to further absorb the heat of the hot side gas turbine cooling air to a supercritical state of 360℃, 2.8MPa, and then enters the turbine 23 to expand and become a gas of 180℃, 0.5MPa, and then flows through the hot side of the regenerator 22 to be precooled to 80℃, 0.4MPa gas, and finally releases heat on the hot side of the condenser 24 to be condensed into a liquid of 30℃, 0.3MPa, thus completing a cycle. At the same time, the 390°C, 1.1MPa gas turbine cooling air is cooled to 180°C, 1.0MPa, and then delivered to gas turbine 13. At this point, ambient temperature water from outside the system, at 25°C, is heated to 70°C on the cold side of condenser 24 and then delivered to bromide refrigeration unit 41, producing 7°C cold water with a unit thermal coefficient of 0.65. This water is then delivered to atomization system 42, reducing the inlet temperature of the gas turbine system's air compressor 11 by 1.2°C, thereby increasing the combined cycle efficiency by 0.15%.

[0065] (3) For the winter operation of natural gas CCPP units, a transcritical inorganic Rankine cycle is adopted, and CO2 is selected as the working fluid. The system operation process is as follows: the liquid CO2 at 18°C and 5.5MPa is pressurized to 25°C and 12MPa by the booster pump 21, and then flows through the cold side of the regenerator 22 to be preheated to a supercritical state of 150°C and 11.9MPa. It then enters the cold side of the TCA30 to further absorb the heat of the turbine cooling air on the hot side to a supercritical state of 410°C and 11.8MPa, and then enters the turbine 23 to expand and become a gas at 180°C and 5.7MPa. It then flows through the hot side of the regenerator 22 to be precooled to a gas at 80°C and 5.6MPa. Finally, it releases heat on the hot side of the condenser 24 and is condensed into a liquid at 18°C and 5.5MPa, thus completing a cycle. At the same time, the 450°C, 2.1 MPa turbine cooling air is cooled by TCA 30 to 280°C, 2.0 MPa, and then sent to turbine 13. Meanwhile, 15°C ambient temperature water from outside the system is heated to 60°C on the cold side of condenser 24 and then supplied to the outside.

[0066] (4) For the summer operation of natural gas CCPP units, a transcritical inorganic Rankine cycle is adopted, and CO2 is selected as the working fluid. The system operation process is as follows: the liquid CO2 at 18°C and 5.5MPa is pressurized to 25°C and 12MPa by the booster pump 21, and then flows through the cold side of the regenerator 22 to be preheated to a supercritical state of 150°C and 11.9MPa. It then enters the cold side of the TCA30 to further absorb the heat of the turbine cooling air on the hot side to a supercritical state of 450°C and 11.8MPa, and then enters the turbine 23 to expand and become a gas at 180°C and 5.7MPa. It then flows through the hot side of the regenerator 22 to be precooled to a gas at 80°C and 5.6MPa. Finally, it releases heat on the hot side of the condenser 24 and is condensed into a liquid at 18°C and 5.5MPa, thus completing a cycle. Simultaneously, the 500°C, 2.1MPa gas turbine cooling air is cooled by TCA 30 to 310°C and 2.0MPa before being sent to gas turbine 13. Meanwhile, ambient-temperature water from outside the system, at 15°C, is heated to 60°C on the cold side of condenser 24 and sent to bromide refrigeration unit 41 to produce 12°C cold water, with a unit thermal coefficient of 0.60. This water is then sent to atomization system 42, reducing the inlet temperature of the gas turbine's air compressor 11 by 1°C, thereby increasing the combined cycle efficiency by 0.1%.

[0067] (5) When the above-mentioned transcritical Rankine cycle operates normally, in the heat storage system, the shell and tube heat exchanger 51 can also release energy to heat the normal temperature water in the water supply pipe 52 at the same time. The normal temperature water of 15°C flows through the tube side of the shell and tube heat exchanger 51, and is heated by the 360°C liquid molten salt in the shell side to become 65°C high-temperature hot water, and then supplies heat to the outside.

[0068] 2. State 2

[0069] When the gas turbine 13 is in a cold start or hot shutdown, the second regulating valve 621 is closed, and the first regulating valve 611 and the third regulating valve 631 are opened. At this time, the transcritical Rankine cycle is not working, and the heat storage system and the gas turbine combined cycle system are working. The 360°C, 1.1MPa gas turbine cooling air flows through the tube side of the shell and tube heat exchanger 51, heating the solid molten salt with a melting point of 360°C in the shell side. The molten salt undergoes a solid-liquid phase change, absorbing the heat of the gas turbine cooling air in the tube side while maintaining its own temperature unchanged, that is, the heat storage system stores heat from the cooling air.

[0070] 3. State 3

[0071] When the gas turbine 13 is operating normally and the cooling air temperature is below 350°C, ideal energy recovery through the transcritical Rankine cycle alone would be ineffective. Therefore, the second and third control valves 621 and 631 are closed, and the first control valve 611 is opened. At this point, the 330°C gas turbine cooling air first flows through the shell-and-tube heat exchanger 51, fully absorbing the heat from the shell-side liquid molten salt. Since the solid-liquid phase transition temperature of the molten salt is 360°C, the gas turbine cooling air in the tube side is stably heated to 360°C, while the shell-side molten salt solidifies. The 360°C gas turbine cooling air then flows through the TCA 30, ensuring stable and efficient operation of the transcritical Rankine cycle.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A gas turbine cooling air multi-energy co-generation system, comprising a gas turbine combined cycle system, wherein the gas turbine combined cycle system comprises an air compressor (11) and a gas turbine (13), characterized in that: Also includes: A transcritical Rankine cycle system, the transcritical Rankine cycle system comprising a booster pump (21), a regenerator (22), a turbine (23) and a condenser (24) connected in sequence to form a loop, the gas turbine combined cycle system and the transcritical Rankine cycle system being coupled via a TCA (30), the cooling air generated by the air compressor (11) being further cooled by the TCA (30) before entering the gas turbine (13), the medium flowing out of the regenerator (22) absorbing heat in the TCA (30) before entering the turbine (23) to expand and perform work; A multi-energy combined supply system, comprising a bromide cooling unit (41) and an atomizing system (42) connected in series, wherein the outlet of the atomizing system (42) is connected to the air inlet of the air compressor (11); cooling water outside the system absorbs heat through a condenser (24) to form high-temperature water, which flows into the bromide cooling unit (41) and provides heat for it; low-temperature water generated by the bromide cooling unit (41) enters the atomizing system (42) to generate micro-mist cold water particles, which are mixed with the intake air of the air compressor (11) to reduce the intake air temperature.

2. A gas turbine cooling air multi-energy cogeneration system according to claim 1, characterized in that: In the transcritical Rankine cycle system, after the medium expands and works in the turbine (23), it first enters the regenerator (22) to perform a heat exchange with the medium from the booster pump (21) in the regenerator (22), and then enters the condenser (24) to perform a secondary heat exchange with the cooling water outside the system.

3. The multi-energy cogeneration system for gas turbine cooling air according to claim 1, characterized in that: The invention also includes a heat storage system, wherein the heat storage system includes a shell and tube heat exchanger (51), the shell and tube heat exchanger (51) is arranged on the main line (61) between the air compressor (11) and the TCA (30), the tube side of the shell and tube heat exchanger (51) is connected to the main line (61), and the shell side of the shell and tube heat exchanger (51) is filled with phase change energy storage material; the air compressor (11) is also connected to the main line (61) between the shell and tube heat exchanger (51) and the TCA (30) through a first branch line (62), and the main line (61) between the shell and tube heat exchanger (51) and the TCA (30) is also connected to the gas turbine (13) through a second branch line (63).

4. A gas turbine cooling air multi-energy cogeneration system according to claim 3, characterized in that: A first regulating valve (611) is provided on the main line (61) between the air compressor (11) and the shell-and-tube heat exchanger (51); a second regulating valve (621) is provided on the first branch line (62); and a third regulating valve (631) is provided on the second branch line (63).

5. A gas turbine cooling air multi-energy cogeneration system according to claim 4, characterized in that: According to the supply and temperature of the cooling air of the gas turbine (13), the operating state of the heat storage system and the transcritical Rankine cycle system is adjusted. Specifically, according to the operating state of the gas turbine (13), the following operations are performed: State 1: When the gas turbine (13) operates normally and the cooling air temperature is above 350°C, the first regulating valve (611) and the third regulating valve (631) are closed, and the second regulating valve (621) is opened; at this time, only the gas turbine combined cycle system and the transcritical Rankine cycle system operate, and the cooling air directly enters the TCA (30) for cooling; State 2: When the combustion engine turbine (13) is in a cold start or hot shutdown state, the second regulating valve (621) is closed, and the first regulating valve (611) and the third regulating valve (631) are opened. At this time, only the heat storage system and the gas turbine combined cycle system are in operation, and the cooling air flows through the shell and tube heat exchanger (51) and then enters the combustion engine turbine (13). The shell and tube heat exchanger (51) stores heat from the cooling air. State 3: When the gas turbine (13) operates normally and the cooling air temperature is lower than 350°C, the second regulating valve (621) and the third regulating valve (631) are closed, and the first regulating valve (611) is opened. At this time, the transcritical Rankine cycle system operates, the gas turbine combined cycle system and the heat storage system all operate, and the cooling air first passes through the shell and tube heat exchanger (51) to absorb heat, and then enters the TCA (30) for cooling.

6. A gas turbine cooling air multi-energy cogeneration system according to claim 5, characterized in that: The tube side of the shell and tube heat exchanger (51) is also connected to a water supply pipeline (52). When the gas turbine (13) is in state 1, the water supply pipeline (52) transports normal temperature water into the tube side of the shell and tube heat exchanger (51). The normal temperature water absorbs the heat stored in the heat storage system and is heated to supply heat to the outside.

7. The multi-energy cogeneration system for gas turbine cooling air according to claim 1, characterized in that: In the multi-energy cogeneration system, the high-temperature water and low-temperature water can also directly provide heating or cooling to the outside of the system.

8. The multi-energy combined supply system for gas turbine cooling air according to claim 1, characterized in that: The transcritical Rankine cycle includes a transcritical organic Rankine cycle and a transcritical inorganic Rankine cycle.

9. The multi-energy cogeneration system for gas turbine cooling air according to claim 1, characterized in that: The turbine (23) is also connected to a generator (231).

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