A method of converting a gas turbine regenerative cycle to a humidification cycle

Abstract

This invention discloses a method for converting a gas turbine regenerative cycle to a humidified cycle. The compressor draws in air, pressurizes it, and discharges it into an aftercooler, where the air exchanges heat with cold water, thus cooling the air. A venting path is installed on the air pipeline between the aftercooler and the humidifier. The amount of air vented is adjusted according to different humidified cycle operating conditions to maintain a relatively constant compressor outlet pressure. Air and hot water come into counter-current contact in the humidifier. The humid air from the humidifier exchanges heat with the gas turbine exhaust in the regenerator before entering the combustion chamber. Natural gas mixes and combusts with the humid air before entering the turbine to perform work. The turbine drives the compressor and generator, which generate electricity. The turbine exhaust passes through the regenerator and economizer, where it exchanges heat with the humid air and water respectively to recover waste heat before being discharged into the atmosphere. This method achieves flow matching between the two systems without modifying the core components of the gas turbine (compressor and turbine), greatly reducing the difficulty of converting existing gas turbine units to a humidified cycle and maintaining a high system energy utilization rate.

Description

Technical Field

[0001] This invention relates to the field of gas turbines, and more specifically to a method for converting a gas turbine regenerative cycle into a humidification cycle. Background Technology

[0002] Gas turbines are currently the most efficient fossil fuel-based large-scale power generation and heat-to-work conversion devices. With economic and social development and the expanding applications of gas turbines, the performance requirements are becoming increasingly stringent. These requirements not only demand higher efficiency and stricter emission controls, but also greater flexibility in cycle load regulation, part-load performance, and susceptibility to environmental conditions. Currently, gas turbines used for power generation primarily employ the Brayden-Rankine combined cycle. However, on the one hand, the potential to improve cycle performance solely by increasing temperature and pressure ratio is diminishing; on the other hand, the limited cycle type makes it difficult to meet the diverse needs of various users.

[0003] The regenerative cycle is a type of thermodynamic cycle in a gas turbine, such as... Figure 1 As shown, C represents the compressor, CB represents the combustion chamber, T represents the turbine, RE represents the regenerator, and G represents the generator. The compressor C draws in air from the atmosphere, compresses it, and then discharges it into the regenerator RE. The air exchanges heat with the exhaust gas from the gas turbine in the regenerator RE before entering the combustion chamber CB. Natural gas (or other fuel) mixes with the hot air and burns, then enters the turbine T to perform work. The turbine T drives the compressor C and the generator G to rotate via a shaft, and the generator G generates electricity. The exhaust gas from the turbine T passes through the regenerator RE and is discharged into the atmosphere to recover heat.

[0004] To better achieve goals such as high efficiency, low emissions, low cost, and high flexibility, while meeting diverse needs, various new thermodynamic cycles based on gas turbines are constantly being proposed and developed. The humidified gas turbine cycle is one of the most representative examples. This type of cycle uses a mixed working fluid (humid air) and performs heat recovery and air humidification at different locations as needed. Depending on the technical approach, air humidification cycles can be broadly classified into three specific forms: cycles with spraying at different locations in the gas path (before / between / after the compressor, etc.); steam-injected gas turbine cycles (STIG or Cheng cycles); and humidified air turbine cycles (HAT cycles) that recover low-grade waste heat through a humidifier for air humidification. Compared with other new power cycles, the common characteristics of humidified gas turbine cycles are: ① reduced compressor power consumption, or (and) full utilization of the internal waste heat of the gas turbine cycle through spraying, steam injection, and humidification processes to improve efficiency; ② air humidification increases the working fluid flow rate and improves the cycle specific power; ③ humidified air combustion effectively reduces NOx emissions from the system; ④ the elimination of steam bottom circulation components results in a more compact structure and reduced costs; ⑤ air humidification increases adjustability and improves the operational flexibility of the system.

[0005] The humidification cycle (HAT cycle) is the representative and main type of air humidification cycle with a water loop. Its process is as follows: Figure 2 As shown, C represents the compressor, CB represents the combustion chamber, T represents the turbine, RE represents the regenerator, G represents the generator, AC represents the aftercooler, EC represents the economizer, H represents the humidifier, and P1 and P2 represent water pumps. Compressor C draws in air from the atmosphere, pressurizes it, and discharges it into aftercooler AC. In aftercooler AC, the air exchanges heat with water from the bottom of humidifier H, and the cooled air is then sent into humidifier H. In humidifier H, the air comes into counter-current contact with hot water, causing the air to heat up and become humid, while the water temperature decreases. The humid air from humidifier H exchanges heat with the exhaust gas from the gas turbine in regenerator RE and then enters combustion chamber CB. Natural gas (or other fuel) mixes with the humid air and is burned before entering turbine T to do work. Turbine T drives compressor C and generator G to rotate via a shaft, and generator G generates electricity. The exhaust gas from turbine T passes through regenerator RE and economizer EC, where it exchanges heat with humid air and water respectively to recover waste heat before being discharged into the atmosphere. The cold water from humidifier H exchanges heat with the flue gas in the economizer, and after being heated, the water mixes with the water from the aftercooler and is sent to the upper part of the humidifier. The bottom of humidifier H is connected to economizer EC via water pump P1. Water pump P2 is connected to the lower side of humidifier H.

[0006] In addition to the common characteristics of air humidification cycles, the HAT cycle has the following unique advantages: ① Water evaporates at varying temperatures within the humidifier, making fuller use of the low-grade waste heat in the system. From a thermodynamic perspective, it is superior to steam injection cycles and combined cycles, and has the potential for the highest power generation efficiency; ② Compared with using air as a cooling medium, using humid air to cool turbine blades can improve cycle efficiency; ③ High efficiency can be achieved over a wide pressure ratio range. Summary of the Invention

[0007] In a humidified cycle, the volumetric flow rate of the compressor outlet gas can increase by more than 20% after the humidification process. However, existing regenerative cycle gas turbine units are designed with compressor flow rate matching in mind, without considering humidification conditions. If they are directly converted to a humidified cycle, the compressor exhaust pressure will increase significantly, causing surge.

[0008] To balance the flow rates of the compressor and turbine, converting existing regenerative cycle gas turbines into humid cycle gas turbines can be achieved by modifying the core components of the gas turbine (compressor or turbine) or by installing an exhaust bypass in the compressor exhaust pipe. Directly modifying the core components of the gas turbine is difficult, and the overall performance of the converted turbine is hard to guarantee; it's equivalent to redesigning the flow matching of a gas turbine, resulting in significant uncertainty in the system conversion. Installing an exhaust bypass in the compressor exhaust pipe, without a process for reusing exhaust heat and pressure, will directly and significantly reduce system efficiency, even resulting in no benefit after the conversion. For these reasons, the lack of feasible technologies and high uncertainty in converting existing gas turbines to humid cycle systems reduces user willingness to convert and hinders the promotion of humid cycle gas turbines.

[0009] Considering the ease of modification, installing an exhaust vent bypass in the compressor exhaust pipeline is a feasible solution. However, the recovery and utilization of exhaust waste heat and pressure must be considered; otherwise, the goal of improving system efficiency through humidification cycle will be difficult to achieve. From the perspective of energy cascade utilization, expander power generation is the preferred option for reusing exhaust waste heat and pressure. However, for small and medium-sized gas turbines widely used in industrial and commercial backup power and distributed energy sectors, due to their compact structure, small power generation scale, and considering factors such as economic efficiency, modification complexity, and low power generation efficiency, the utilization of exhaust waste heat and pressure can be combined with the characteristics of distributed energy supply, utilizing waste heat and pressure in a cascaded and multi-purpose manner, resulting in higher overall energy utilization efficiency.

[0010] This invention proposes a method for converting an existing gas turbine regenerative cycle to a humidified cycle. The method utilizes the residual heat and pressure of the compressor vented exhaust gas to create a humidified gas turbine cycle, thereby improving system energy efficiency. Based on the concept of energy cascade utilization, a residual heat and pressure process for the compressor vented exhaust gas is implemented. First, high-grade waste heat from the exhaust gas is recovered for heating the humidified water in the humidified gas turbine cycle, improving the efficiency of the humidified cycle. Then, the residual pressure process is divided into three operating modes: summer, winter, and spring / autumn. In winter mode, low-grade waste heat from the exhaust gas is recovered for heating, and the residual pressure drives a pneumatic water pump to pressurize the humidified water in the gas turbine cycle. In summer mode, low-grade waste heat from the exhaust gas is directly dissipated to the atmosphere. The cooled compressed air performs work in an adiabatic expander, rapidly cooling down after expansion, and the cold air is directly used for building ventilation. In spring / autumn mode, low-grade waste heat from the exhaust gas is directly dissipated to the atmosphere, and the residual pressure is directly used to drive the pneumatic water pump.

[0011] The present invention adopts the following technical solution:

[0012] A method for converting a gas turbine regenerative cycle to a humidification cycle is disclosed. The compressor C draws in air from the atmosphere, pressurizes it, and discharges it into the aftercooler AC. In the aftercooler AC, the air exchanges heat with cold water, thus cooling the air. A vent is installed on the air pipeline between the aftercooler AC and the humidifier H, through which some air is discharged. The amount of air vented is adjusted by a valve according to different humidification cycle operating conditions to maintain the compressor C outlet pressure variation within 3%. In the humidifier H, air comes into counter-current contact with hot water, causing the air to heat up and become humidified, while the water temperature decreases. The humid air from the humidifier H exchanges heat with the gas turbine exhaust in the regenerator RE and then enters the combustion chamber CB. Natural gas or other fuel mixes with the humid air and combusts before entering the turbine to perform work. The turbine T drives the compressor C and generator G to rotate via a shaft, generating electricity. The turbine exhaust passes through the regenerator RE and the economizer EC, where it exchanges heat with the humid air and water respectively to recover waste heat before being discharged into the atmosphere.

[0013] The water from the outlet of humidifier H is divided into two streams after passing through the heat exchanger WC and enters the aftercooler AC and the economizer EC respectively. After the water is heated, it is mixed and sent back to humidifier H.

[0014] In this invention, maintaining the change in the outlet pressure of compressor C to no more than 3% means maintaining the change in the outlet pressure of compressor C within the range of -3% to 3%.

[0015] Furthermore, the method of changing the gas turbine regenerative cycle to a humidified cycle uses a humidified gas turbine cycle system that utilizes the residual heat and pressure of the compressor vented exhaust. The cycle system includes a compressor C, a combustion chamber CB, a turbine T, a regenerator RE, a generator G, an aftercooler AC, an economizer EC, a humidifier H, a heat exchanger WC, a cooling heat exchanger CT, an adiabatic expander EP, a first electric water pump P1, a pneumatic water pump P3, a first valve V1, and a second valve V2.

[0016] The compressor C gas inlet is connected to the atmosphere, and the compressor C gas outlet is connected to the aftercooler AC gas inlet. The aftercooler AC gas outlet is divided into two paths: one path is connected to the cooling heat exchanger CT gas inlet, and the other path is connected to the humidifier H gas inlet. The humidifier H gas outlet is connected to the regenerator RE air inlet, the regenerator RE air outlet is connected to the combustion chamber CB air inlet, the combustion chamber CB fuel inlet is connected to the natural gas source, and the combustion chamber CB gas outlet is connected to the turbine T gas inlet. The exhaust port of turbine T is connected to the flue gas inlet of regenerator RE, the flue gas outlet of regenerator RE is connected to the flue gas inlet of economizer EC, and the flue gas outlet of economizer EC is connected to the atmosphere; the gas outlet of cooling heat exchanger CT is divided into two paths: one path is connected in sequence to the first valve V1 and the gas source inlet of pneumatic water pump P3, and the gas source outlet of pneumatic water pump P3 is connected to the atmosphere; the other path is connected in sequence to the second valve V2 and the gas inlet of adiabatic expander EP, and the gas outlet of adiabatic expander EP is connected to the building air conditioning duct.

[0017] The water path at the bottom of the humidifier H is divided into two paths: one path is connected to the inlet of the first electric water pump P1, and the other path is connected to the inlet of the pneumatic water pump P3. The outlet of the first electric water pump P1 and the outlet of the pneumatic water pump P3 merge and are connected to the humidification water inlet of the heat exchanger WC. The humidification water outlet of the heat exchanger WC is divided into two paths: one path is connected to the water inlet of the aftercooler AC, and the other path is connected to the water inlet of the economizer EC. The water outlet of the aftercooler AC and the water outlet of the economizer EC merge and are connected to the humidification water inlet of the humidifier H.

[0018] The generator G, compressor C, and turbine T are connected to each other via the same shaft.

[0019] Furthermore, the method includes a summer mode, a winter mode, and a spring / autumn mode.

[0020] Furthermore, in summer mode: the first valve V1 is closed, the second valve V2 adjusts the air volume of the venting path, the air exchanges heat with cooling water (usually from the cooling tower) in the cooling heat exchanger CT to cool down, and uses the residual pressure of the air to do work in the adiabatic expander EP to further cool down and become cold air. The cold air is directly connected to the building air conditioning duct as fresh air for cooling; at the heat exchanger WC, the heat network water circulation is stopped.

[0021] Furthermore, in winter mode: the second valve V2 is closed, and the first valve V1 regulates the air volume in the venting path; at the heat network regenerator WC, the humidifier outlet water exchanges heat with the heat network water (building air conditioning heat network return water), reducing the inlet water temperature of the aftercooler and economizer, thereby reducing the air temperature in the venting path and the final exhaust temperature, and recovering the waste heat of the air in the venting path; the electric water pump and the pneumatic water pump work simultaneously, with the air using residual pressure to drive the pneumatic water pump to work at full load, and the electric water pump is regulated by frequency converter to maintain a constant water flow rate into the aftercooler AC and the economizer EC; at the cooling heat exchanger CT, the cooling water circulation is stopped.

[0022] Furthermore, in the spring and autumn mode: the second valve V2 is closed, and the first valve V1 regulates the amount of air in the venting path; the air exchanges heat with cooling water (usually from the cooling tower) in the cooling heat exchanger CT to cool down, and uses the residual pressure of the cooled air to drive the pneumatic water pump to work at full load. The electric water pump is regulated by frequency converter to maintain a constant water flow into the aftercooler AC and the economizer EC; at the heat exchanger WC, the heat network water circulation is stopped.

[0023] Beneficial effects:

[0024] This invention proposes a method for converting a gas turbine regenerative cycle to a humidified cycle. Using this technical solution, flow matching between the two systems can be achieved without modifying the core components of the gas turbine (compressor and turbine), significantly reducing the difficulty of retrofitting existing gas turbine units to humidified cycles while maintaining high system energy efficiency. This provides an effective technical path for converting existing gas turbine regenerative cycle units to humidified cycles. Attached Figure Description

[0025] Figure 1 Gas turbine regenerative cycle; in the diagram, C represents the compressor, CB represents the combustion chamber, T represents the turbine, RE represents the regenerator, and G represents the generator;

[0026] Figure 2 Typical HAT cycle flow diagram; In the diagram, C represents the compressor, CB represents the combustion chamber, T represents the turbine, RE represents the regenerator, G represents the generator, AC represents the aftercooler, EC represents the economizer, H represents the humidifier, and P11 and P12 represent water pumps.

[0027] Figure 3 This invention relates to a humidified gas turbine cycle that utilizes the residual heat and pressure of the compressor vented exhaust. In the figure, C represents the compressor, CB represents the combustion chamber, T represents the turbine, RE represents the regenerator, G represents the generator, AC represents the aftercooler, EC represents the economizer, H represents the humidifier, WC represents the heat exchanger, CT represents the cooling heat exchanger, EP represents the adiabatic expander, P1 represents the first electric water pump, P2 represents the second electric water pump, P3 represents the pneumatic water pump, V1 represents the first valve, and V2 represents the second valve. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. However, the following embodiments are only for explaining the present invention, and the scope of protection of the present invention should include all the contents of the claims. Moreover, through the description of the following embodiments, those skilled in the art can fully implement all the contents of the claims of the present invention.

[0029] The humidified gas turbine cycle process, which utilizes the residual heat and pressure of the compressor vented exhaust, is as follows: Figure 3 As shown, C represents the compressor, CB represents the combustion chamber, T represents the turbine, RE represents the regenerator, G represents the generator, AC represents the aftercooler, EC represents the economizer, H represents the humidifier, WC represents the heat exchanger, CT represents the cooling heat exchanger, EP represents the adiabatic expander, P1 represents the first electric water pump, P2 represents the second electric water pump, P3 represents the pneumatic water pump, V1 represents the first valve, and V2 represents the second valve. Figure 3As shown, the humidified gas turbine cycle system of the present invention, which utilizes the residual heat and pressure of the compressor vented exhaust, includes a compressor C, a combustion chamber CB, a turbine T, a regenerator RE, a generator G, an aftercooler AC, an economizer EC, a humidifier H, a heat exchanger WC, a cooling heat exchanger CT, an adiabatic expander EP, a first electric water pump P1, a second electric water pump P2, a pneumatic water pump P3, a first valve V1, and a second valve V2. In terms of the gas path, the gas inlet of compressor C is connected to the atmosphere, and the gas outlet of compressor C is connected to the gas inlet of aftercooler AC. The gas outlet of aftercooler AC is divided into two paths: one path is connected to the gas inlet of cooling heat exchanger CT, and the other path is connected to the gas inlet of humidifier H. The gas outlet of the humidifier H is connected to the air inlet of the regenerator RE. The air outlet of the regenerator RE is connected to the air inlet of the combustion chamber CB. The fuel inlet of the combustion chamber CB is connected to the natural gas source. The gas outlet of the combustion chamber CB is connected to the gas inlet of the turbine T. The exhaust port of the turbine T is connected to the flue gas inlet of the regenerator RE. The flue gas outlet of the regenerator RE is connected to the flue gas inlet of the economizer EC. The flue gas outlet of the economizer EC is connected to the atmosphere. The gas outlet of the cooling heat exchanger CT is divided into two paths: one path is connected to the inlet of the pneumatic water pump P3 (with a first valve V1 installed in the intermediate pipeline), and the outlet of the pneumatic water pump P3 is connected to the atmosphere; the other path is connected to the gas inlet of the adiabatic expander EP (with a second valve V2 installed in the intermediate pipeline), and the gas outlet of the adiabatic expander EP is connected to the building air conditioning duct. In terms of water supply, the water path at the bottom of the humidifier H is divided into two paths: one connected to the inlet of the first electric water pump P1, and the other connected to the inlet of the pneumatic water pump P3. The outlet of the first electric water pump P1 and the outlet of the pneumatic water pump P3 merge and connect to the humidification water inlet of the heat exchanger WC. The heat network water inlet and outlet of the heat exchanger WC are connected to the heat network. The humidification water outlet of the heat exchanger WC is divided into two paths: one connected to the water inlet of the aftercooler AC, and the other connected to the water inlet of the economizer EC. The water outlet of the aftercooler AC and the water outlet of the economizer EC merge and connect to the humidification water inlet of the humidifier H. The water inlet of the second electric water pump P2 is connected to the water source, and the water outlet of the second electric water pump P2 is connected to the water supply port of the humidifier H. Mechanically, the generator G, compressor C, and turbine T are interconnected via the same shaft.

[0030] A process for converting a gas turbine regenerative cycle to a humidified cycle is described above. The humidified gas turbine cycle system utilizes the residual heat and pressure of the compressor vented exhaust. The process flow is divided into three modes: summer mode, winter mode, and spring / autumn mode.

[0031] Summer Mode:

[0032] Airflow path: Compressor C draws in air from the atmosphere, pressurizes it, and discharges it into aftercooler AC. In aftercooler AC, the air exchanges heat with chilled water and is cooled. A vent is installed on the air pipeline between aftercooler AC and humidifier H. Some air is drawn out through this vent. Depending on the humidification cycle conditions, the amount of air in the vent is adjusted by the second valve V2 to maintain the pressure change at compressor C outlet not exceeding 3%. The vent air exchanges heat with cooling water (usually from a cooling tower) in cooling heat exchanger CT and is cooled down. The residual air pressure is used to do work in adiabatic expander EP to further cool down the air and become cold air. The cold air is directly connected to the building air conditioning duct as fresh air for cooling. In the humidifier H, air and hot water come into countercurrent contact, causing the air to heat up and become humid, while the water temperature decreases. The humid air from the humidifier H exchanges heat with the exhaust gas from the gas turbine in the regenerator RE and then enters the combustion chamber CB. In the combustion chamber CB, natural gas (or other fuel) mixes and burns with the humid air before entering the turbine T to do work. The turbine T drives the compressor C and generator G to rotate via a shaft, and the generator G generates electricity. The exhaust gas from the turbine T passes through the regenerator RE and the economizer EC, where it exchanges heat with the humid air and water respectively to recover waste heat before being discharged into the atmosphere. The first valve V1 is closed, and the pneumatic water pump P3 does not work.

[0033] Water flow: The water from the outlet of humidifier H is divided into two streams after passing through the heat exchanger WC and enters the aftercooler AC and the economizer EC respectively. After the water is heated, it is mixed and sent back to humidifier H. At the heat exchanger WC, the heat network water circulation stops.

[0034] Winter Mode:

[0035] Airflow path: Compressor C draws in air from the atmosphere, pressurizes it, and then discharges it into aftercooler AC; in aftercooler AC, the air exchanges heat with cold water and is cooled; a vent is set on the air pipeline between aftercooler AC and humidifier H, and part of the air is led out through this vent. Depending on the humidification cycle conditions, the amount of air vented is adjusted by the first valve V1 to maintain the pressure change at compressor C outlet not exceeding 3%. The residual pressure of the air drives pneumatic water pump P3 to work at full load. In the humidifier H, air and hot water come into countercurrent contact, causing the air to heat up and become humid, while the water temperature decreases. The humid air from the humidifier H exchanges heat with the exhaust gas from the gas turbine in the regenerator RE and then enters the combustion chamber CB. In the combustion chamber CB, natural gas (or other fuel) mixes and burns with the humid air before entering the turbine T to do work. The turbine T drives the compressor C and generator G to rotate via a shaft, and the generator G generates electricity. The exhaust gas from the turbine T passes through the regenerator RE and the economizer EC, where it exchanges heat with the humid air and water respectively to recover waste heat before being discharged into the atmosphere. The second valve V2 is closed, and the adiabatic expander EP does not work.

[0036] Water flow path: The water outlet of humidifier H is divided into two streams after passing through the heat exchanger WC and enters the aftercooler AC and economizer EC respectively. After the water is heated, it is mixed and sent back to humidifier H. At the heat exchanger WC, the humidifier outlet water exchanges heat with the heat exchanger water (return water from the building air conditioning heat exchanger), which reduces the inlet water temperature of aftercooler AC and economizer EC, thereby reducing the air temperature of the vent circuit and the final exhaust temperature, and recovering the waste heat of the vent circuit air. By adjusting the frequency converter, the total water volume of electric water pump P1 and pneumatic water pump P3 is kept basically constant (the flow rate deviation is controlled within ±10%), maintaining the water flow rate entering aftercooler AC and economizer EC. At the cooling heat exchanger CT, the cooling water circulation is stopped.

[0037] Spring and Autumn Mode:

[0038] Airflow path: Compressor C draws in air from the atmosphere, pressurizes it, and discharges it into aftercooler AC; in aftercooler AC, the air exchanges heat with cold water and is cooled; a vent is set on the air pipeline between aftercooler AC and humidifier H, and part of the air is led out through this vent. Depending on the humidification cycle conditions, the amount of air vented is adjusted by the first valve V1 to maintain the pressure change at compressor C outlet not exceeding 3%. The air exchanges heat with cooling water (usually from a cooling tower) in cooling heat exchanger CT to cool down, and the residual pressure of the cooled air drives pneumatic water pump P3 to work at full load. In the humidifier H, air and hot water come into countercurrent contact, causing the air to heat up and become humid, while the water temperature decreases. The humid air from the humidifier H exchanges heat with the exhaust gas from the gas turbine in the regenerator RE and then enters the combustion chamber CB. In the combustion chamber CB, natural gas (or other fuel) mixes and burns with the humid air before entering the turbine T to do work. The turbine T drives the compressor C and generator G to rotate via a shaft, and the generator G generates electricity. The exhaust gas from the turbine T passes through the regenerator RE and the economizer EC, where it exchanges heat with the humid air and water respectively to recover waste heat before being discharged into the atmosphere. The second valve V2 is closed, and the adiabatic expander EP does not work.

[0039] Water flow path: Water from the outlet of humidifier H is divided into two streams after passing through the heat exchanger WC and enters the aftercooler AC and economizer EC respectively. After the water is heated, it is mixed and sent back to humidifier H. The total water volume of electric water pump P1 and pneumatic water pump P3 is kept basically constant by frequency conversion regulation (flow rate deviation is controlled within ±10%), maintaining the water flow rate entering aftercooler AC and economizer EC. At the heat exchanger WC, the heat network water circulation is stopped.

[0040] The parts of this invention not described in detail are well-known to those skilled in the art. The embodiments described above are merely preferred embodiments of the invention, and do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Various modifications and improvements to the technical solutions of this invention made by those skilled in the art without departing from the spirit of the invention should fall within the protection scope defined by the claims of this invention.

Claims

1. A method for converting a gas turbine regenerative cycle to a humidification cycle, characterized in that, The compressor (C) draws in air from the atmosphere, pressurizes it, and discharges it into the aftercooler (AC). In the aftercooler (AC), the air exchanges heat with cold water and is cooled. A vent is installed on the air pipeline between the aftercooler (AC) and the humidifier (H), through which some air is led out. Depending on the humidification cycle conditions, the amount of air vented is adjusted by a valve to maintain the compressor (C) outlet pressure variation within 3%. In the humidifier (H), the air comes into countercurrent contact with hot water, causing the air to heat up and become humid, while the water temperature decreases. The humid air from the humidifier (H) exchanges heat with the gas turbine exhaust in the regenerator (RE) and then enters the combustion chamber (CB). Natural gas mixes and burns with the humid air before entering the turbine to do work. The turbine (T) drives the compressor (C) and generator (G) to rotate via a shaft, and the generator (G) generates electricity. The turbine exhaust passes through the regenerator (RE) and the economizer (EC), where it exchanges heat with the humid air and water respectively to recover waste heat before being discharged into the atmosphere. The water outlet of the humidifier (H) is divided into two streams after passing through the heat exchanger (WC) and enters the aftercooler (AC) and economizer (EC) respectively. After the water is heated, it is mixed and sent back to the humidifier (H). The method of changing the gas turbine regenerative cycle to a humidified cycle uses a humidified gas turbine cycle system that utilizes the residual heat and pressure of the compressor vented exhaust. The cycle system includes a compressor (C), a combustion chamber (CB), a turbine (T), a regenerator (RE), a generator (G), an aftercooler (AC), an economizer (EC), a humidifier (H), a heat exchanger (WC), a cooling heat exchanger (CT), an adiabatic expander (EP), a first electric water pump (P1), a pneumatic water pump (P3), a first valve (V1), and a second valve (V2). The compressor (C) gas inlet is connected to the atmosphere, and the compressor (C) gas outlet is connected to the aftercooler (AC) gas inlet. The aftercooler (AC) gas outlet is divided into two paths: one path is connected to the cooling heat exchanger (CT) gas inlet, and the other path is connected to the humidifier (H) gas inlet. The humidifier (H) gas outlet is connected to the regenerator (RE) air inlet, and the regenerator (RE) air outlet is connected to the combustion chamber (CB) air inlet. The combustion chamber (CB) fuel inlet is connected to the natural gas source, and the combustion chamber (CB) gas outlet is connected to the turbine (T) gas inlet. The turbine (T) exhaust port is connected to the flue gas inlet of the regenerator (RE), the flue gas outlet of the regenerator (RE) is connected to the flue gas inlet of the economizer (EC), and the flue gas outlet of the economizer (EC) is connected to the atmosphere; the cooling heat exchanger (CT) gas outlet is divided into two paths: one path is connected in sequence to the first valve (V1) and the pneumatic water pump (P3) drive gas source inlet, and the pneumatic water pump (P3) drive gas source outlet is connected to the atmosphere; the other path is connected in sequence to the second valve (V2) and the adiabatic expander (EP) gas inlet, and the adiabatic expander (EP) gas outlet is connected to the building air conditioning duct. The water path at the bottom of the humidifier (H) is divided into two paths: one path is connected to the inlet of the first electric water pump (P1), and the other path is connected to the inlet of the pneumatic water pump (P3). The outlet of the first electric water pump (P1) and the outlet of the pneumatic water pump (P3) are combined and then connected to the humidification water inlet of the heat exchanger (WC). The humidification water outlet of the heat exchanger (WC) is divided into two paths: one path is connected to the water inlet of the aftercooler (AC), and the other path is connected to the water inlet of the economizer (EC). The water outlet of the aftercooler (AC) and the water outlet of the economizer (EC) are combined and then connected to the humidification water inlet of the humidifier (H). The generator (G), compressor (C), and turbine (T) are interconnected via the same shaft.

2. The method according to claim 1, characterized in that, The method includes summer mode, winter mode, and spring / autumn mode.

3. The method according to claim 2, characterized in that, Summer mode: The first valve (V1) is closed, the second valve (V2) adjusts the air volume of the venting path, the air exchanges heat with the cooling water in the cooling heat exchanger (CT) to cool down, and uses the residual pressure of the air to do work in the adiabatic expander (EP) to further cool down and become cold air. The cold air is directly connected to the building air conditioning duct as fresh air for cooling; at the heat exchanger (WC), the heat network water circulation is stopped.

4. The method according to claim 2, characterized in that, Winter mode: The second valve (V2) is closed, and the first valve (V1) regulates the air volume in the venting path; at the heat network regenerator (WC), the humidifier outlet water exchanges heat with the heat network water, reducing the inlet water temperature of the aftercooler and economizer, thereby reducing the air temperature in the venting path and the final flue gas temperature, and recovering the waste heat of the air in the venting path; the electric water pump and the pneumatic water pump work simultaneously, and the air uses residual pressure to drive the pneumatic water pump to work at full load. The electric water pump is regulated by frequency converter to maintain a constant water flow rate into the aftercooler (AC) and economizer (EC); at the cooling heat exchanger (CT), the cooling water circulation is stopped.

5. The method according to claim 2, characterized in that, Spring and Autumn Mode: The second valve (V2) is closed, and the first valve (V1) regulates the air volume in the venting path; the air exchanges heat with the cooling water in the cooling heat exchanger (CT) to cool down, and uses the residual pressure of the cooled air to drive the pneumatic water pump to work at full load. The electric water pump is regulated by frequency converter to maintain a constant water flow into the aftercooler (AC) and economizer (EC); at the heat network heat exchanger (WC), the heat network water circulation stops.

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