A bypass system for an intercooled cycle gas turbine

Abstract

This invention provides a bypass system for an intercooled cycle gas turbine, comprising a three-shaft intercooled cycle gas turbine, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine, a power turbine, and an intercooler. An intercooler inlet transition section is provided between the low-pressure compressor and the intercooler, and an intercooler outlet transition section is provided between the intercooler and the high-pressure compressor. By adding a bypass system with a control valve to the intercooler inlet transition section and the intercooler outlet transition section of the three-shaft intercooled cycle gas turbine, before the intercooled cycle gas turbine starts, an electric actuator first opens the control valve, placing the control valve on the bypass flow path in the open position. After successful and stable combustion in the combustion chamber, once the high-pressure rotor speed reaches a certain value, the control valve is gradually closed, eventually reaching the closed position. This technology enables the rapid start-up of the three-shaft intercooled cycle gas turbine.

Description

Technical Field

[0001] This invention belongs to the field of gas turbine technology, specifically relating to a bypass system for an intercooled cycle gas turbine. Background Technology

[0002] A simple cycle three-shaft gas turbine unit mainly includes large components such as a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine, and a power turbine. One way to increase the useful work of the gas turbine unit and reduce the power consumption of the compressor is to add an intercooler assembly and its matching circulating cooling system between the high-pressure compressor and the low-pressure compressor, thereby obtaining an intercooled cycle gas turbine.

[0003] Currently, when gas turbines are in operation, due to the large airflow, the compressed air carries a significant amount of heat in order to reduce the temperature of the air entering the high-pressure compressor to a lower range. This results in a large intercooler assembly. When the time constant is large, the influence of volumetric inertia on airflow and resistance losses cannot be ignored during the start-up transition. Therefore, it is necessary to ensure that the air at the low-pressure compressor outlet flows through the intercooler assembly as quickly as possible before entering the high-pressure compressor, so that the high-pressure rotor reaches the ignition speed, and to ensure that the air entering the combustion chamber reaches the minimum flow rate. This is very unfavorable to the requirement of rapid start-up during the start-up of intercooled cycle gas turbines. Summary of the Invention

[0004] The purpose of this invention is to provide a bypass system for an intercooled cycle gas turbine, which aims to solve the problems that bypass systems lack compact structure, simple system, convenient operation and high reliability.

[0005] This invention is implemented as follows: a bypass system for an intercooled cycle gas turbine, comprising a three-shaft intercooled cycle gas turbine, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine, a power turbine, and an intercooler; an intercooler inlet transition section is provided between the low-pressure compressor and the intercooler, and an intercooler outlet transition section is provided between the intercooler and the high-pressure compressor; a bypass system is provided between the intercooler inlet transition section and the intercooler outlet transition section; the bypass system includes a valve inlet transition channel, a valve outlet transition channel, a control valve, a control box, and an electric actuator; the control valve includes an annular valve disc, a gear drive shaft, and a sealing gasket; a support plate is provided on the outer wall of the intercooler inlet transition section; the gear drive shaft is respectively equipped with a bevel gear, a bushing, a sleeve, a nut, and a spline; and a bearing, an end cover, and a rubber gasket are respectively provided on the mounting seat supporting the gear drive shaft in the inner hole of the support plate.

[0006] Furthermore, the inlet transition section and the outlet transition section of the intercooler are designed as two independent components, and the inlet transition section and the outlet transition section of the intercooler are assembled by bolt connection.

[0007] Furthermore, the end face of the annular valve disc is provided with gear teeth, which mesh with the bevel gear of the gear transmission shaft to transmit motion.

[0008] Furthermore, the annular valve disc and sealing gasket are installed between the valve inlet transition channel and the valve outlet transition channel, and the annular valve disc can rotate freely around the gas turbine axis.

[0009] Furthermore, the gear drive shaft is connected to the gear teeth on the end face of the annular valve disc via a bevel gear.

[0010] Furthermore, there are two support plates, and the two support plates are arranged circumferentially on the inner wall of the inlet transition section of the intercooler.

[0011] Furthermore, the number of sealing gaskets is four, and all four sealing gaskets are made of circular rubber material.

[0012] The beneficial effects of this invention are as follows: By adding a bypass system with a control valve to the intercooler inlet transition section and the intercooler outlet transition section of the three-shaft intercooled cycle gas turbine, before the three-shaft intercooled cycle gas turbine is started, the electric actuator first opens the control valve, so that the control valve on the bypass flow channel is in the open position. After successful ignition and stable combustion in the combustion chamber, once the high-pressure rotor speed reaches a certain speed value, the control valve can be gradually closed and finally placed in the closed position. By adopting this technology, the requirement for rapid start-up of the three-shaft intercooled cycle gas turbine can be achieved. Attached Figure Description

[0013] Figure 1 This is a simplified schematic diagram of the three-shaft intercooled cycle gas turbine of the present invention;

[0014] Figure 2 This is a schematic diagram of the intercooler assembly and bypass system structure of the present invention;

[0015] Figure 3 This is the present invention. Figure 1 Cross-sectional view of BB in the middle. Figure 3 -a indicates that the annular valve disc is in the open position. Figure 3 -b indicates a schematic diagram of the annular valve disc in the closed position;

[0016] Figure 4 This is the present invention. Figure 1 Sectional view of AA in the middle. Figure 4 -a indicates that the annular valve disc is in the closed position before rotation. Figure 4 -b indicates the annular valve disc is in the open position after rotation.

[0017] In the diagram: 1. Three-shaft intercooled cycle gas turbine; 2. Low-pressure compressor; 3. High-pressure compressor; 4. Combustion chamber; 5. High-pressure turbine; 6. Low-pressure turbine; 7. Power turbine; 8. Intercooler; 9. Intercooler inlet transition section; 10. Intercooler outlet transition section; 11. Bypass system; 12. Valve inlet transition channel; 13. Valve outlet transition channel; 14. Control valve; 15. Control box; 16. Electric actuator; 17. Annular valve disc; 18. Gear drive shaft; 19. Sealing gasket; 20. Bevel gear; 21. Bushing; 22. Sleeve; 23. Nut; 24. Spline; 25. Bearing; 26. End cover; 27. Rubber gasket; 28. Gear tooth; 29. ​​Support plate. Detailed Implementation

[0018] The present invention will now be further described with reference to the accompanying drawings.

[0019] This invention provides a bypass system for an intercooled cycle gas turbine, such as... Figure 1-4 As shown, the system includes a three-shaft intercooled cycle gas turbine 1, a low-pressure compressor 2, a high-pressure compressor 3, a combustion chamber 4, a high-pressure turbine 5, a low-pressure turbine 6, a power turbine 7, and an intercooler 8. An intercooler inlet transition section 9 is provided between the low-pressure compressor 2 and the intercooler 8, and an intercooler outlet transition section 10 is provided between the intercooler 8 and the high-pressure compressor 3. A bypass system 11 is provided between the intercooler inlet transition section 9 and the intercooler outlet transition section 10. The bypass system 11 includes a valve inlet transition flow... The system includes a flow channel 12, a valve outlet transition flow channel 13, a control valve 14, a control box 15, and an electric actuator 16. The control valve 14 includes an annular valve disc 17, a gear drive shaft 18, and a sealing gasket 19. A support plate 29 is provided on the outer wall of the intercooler inlet transition section 9. The gear drive shaft 18 is equipped with a bevel gear 20, a bushing 21, a sleeve 22, a nut 23, and a spline 24. The mounting seat supporting the gear drive shaft 18 in the inner hole of the support plate 29 is equipped with a bearing 25, an end cover 26, and a rubber gasket 27.

[0020] It should be noted that, due to the large airflow during operation of existing gas turbines, the compressed air carries a significant amount of heat in order to lower the inlet air temperature of the high-pressure compressor 3 to a lower range. This results in a large intercooler assembly. When the time constant is large, the influence of volumetric inertia on airflow and drag losses cannot be ignored during the start-up transition. Therefore, to ensure that the air from the outlet of the low-pressure compressor 2 flows through the intercooler assembly as quickly as possible before entering the high-pressure compressor 3, allowing the high-pressure rotor to reach its ignition speed, and to ensure that the air entering the combustion chamber 4 reaches its minimum flow rate, this is highly unfavorable to the requirement of rapid start-up during the start-up of an intercooled cycle gas turbine. To address the shortcomings of existing bypass systems in terms of compact structure, simplicity, ease of operation, and high reliability, this solution adds a bypass system 11 with a control valve 14 to the intercooler inlet transition section 9 and the intercooler outlet transition section 10 of the three-shaft intercooled cycle gas turbine 1. Before starting the three-shaft intercooled cycle gas turbine 1, the electric actuator 16 first opens the control valve 14, placing it in the open position. After successful and stable combustion in the combustion chamber 4, once the high-pressure rotor speed reaches a certain value, the control valve 14 is gradually closed until it is finally in the closed position. This technology enables the rapid start-up of the three-shaft intercooled cycle gas turbine 1.

[0021] Specifically, in this embodiment, the solution mainly includes the design of the intercooler inlet transition section 9 and the intercooler outlet transition section 10 as two independent components, which are assembled by bolt connection.

[0022] In a further preferred embodiment of the present invention, such as Figure 2-4 As shown, the end face of the annular valve disc 17 is provided with gear teeth 28. The gear teeth 28 mesh with the bevel gear 20 of the gear transmission shaft 18 to transmit motion. The end face of the annular valve disc 17 has bevel teeth. The gear teeth 28 on the gear transmission shaft 18 mesh with the bevel teeth on the annular valve disc 17 to realize the rotation of the annular valve disc 17 driven by the gear transmission shaft 18.

[0023] In this embodiment, when the three-shaft intercooled cycle gas turbine 1 is started, the bypass system 11 is put into operation. The electric actuator 16 is controlled by the control box 15 to keep the control valve 14 in the open position. During the start-up process of the three-shaft intercooled cycle gas turbine 1, since the pressure loss of the bypass system 11 added in the transition section is relatively small, most of the compressed air discharged from the low-pressure compressor 2 is directly sucked into the high-pressure compressor 3 through the bypass system 11. When the high-pressure rotor reaches the ignition speed as soon as possible, the air flow rate entering the combustion chamber 4 reaches the minimum flow rate value. At this time, it can ensure normal ignition and stable combustion in the combustion chamber 4. After the high-pressure rotor speed reaches a certain speed value, the annular valve disc 17 of the control valve 14 can be gradually closed, and finally the annular valve disc 17 is in the closed position.

[0024] In a further preferred embodiment of the present invention, such as Figure 2-4 As shown, the annular valve disc 17 and the sealing gasket 19 are installed between the valve inlet transition channel 12 and the valve outlet transition channel 13. The annular valve disc 17 can rotate freely around the gas turbine axis.

[0025] In this embodiment, air leakage from the outlet transition channel 13 to the inlet transition channel 12 can be avoided, thus improving the sealing performance.

[0026] In a further preferred embodiment of the present invention, such as Figure 2-4 As shown, the gear drive shaft 18 is connected to the gear teeth 28 on the end face of the annular valve disc 17 via a bevel gear 20.

[0027] In this embodiment, the gear transmission shaft 18 drives the annular valve disc 17 to rotate by having bevel teeth on the end face of the annular valve disc 17, and the gear teeth 28 on the gear transmission shaft 18 mesh with the bevel teeth on the annular valve disc 17.

[0028] In a further preferred embodiment of the present invention, such as Figure 2 As shown, there are two support plates 29, and the two support plates 29 are arranged along the circumferential direction on the inner wall of the intercooler inlet transition section 9.

[0029] In this embodiment, it is convenient to install and connect the mounting base of the gear drive shaft 18 of the control valve 14.

[0030] In a further preferred embodiment of the present invention, such as Figure 2-4 As shown, there are four sealing gaskets 19, and all four sealing gaskets 19 are made of round rubber.

[0031] In this embodiment, four circular sealing gaskets 19 are respectively placed between the annular valve disc 17 and the intercooler inlet transition section 9 and the intercooler outlet transition section 10 to prevent air leakage from the valve outlet transition channel 13 into the valve inlet transition channel 12.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A bypass system for an intercooled cycle gas turbine, characterized in that, The system includes a three-shaft intercooled cycle gas turbine (1), a low-pressure compressor (2), a high-pressure compressor (3), a combustion chamber (4), a high-pressure turbine (5), a low-pressure turbine (6), a power turbine (7), and an intercooler (8). An intercooler inlet transition section (9) is provided between the low-pressure compressor (2) and the intercooler (8), and an intercooler outlet transition section (10) is provided between the intercooler (8) and the high-pressure compressor (3). A bypass system (11) is provided between the intercooler inlet transition section (9) and the intercooler outlet transition section (10). The bypass system (11) includes a valve inlet transition channel (12). The valve outlet transition channel (13), control valve (14), control box (15) and electric actuator (16) are provided. The control valve (14) includes an annular valve disc (17), gear drive shaft (18) and sealing gasket (19). The outer wall of the intercooler inlet transition section (9) is provided with a support plate (29). The gear drive shaft (18) is respectively equipped with a bevel gear (20), bushing (21), sleeve (22), nut (23) and spline (24). The mounting seat supporting the gear drive shaft (18) in the inner hole of the support plate (29) is respectively equipped with a bearing (25), end cover (26) and rubber gasket (27). The annular valve disc (17) and the sealing gasket (19) are installed between the valve inlet transition channel (12) and the valve outlet transition channel (13). The annular valve disc (17) can rotate freely around the gas turbine axis. The end face of the annular valve disc (17) is provided with gear teeth (28), and the gear teeth (28) mesh with the bevel gear (20) of the gear transmission shaft (18) to transmit motion. The gear drive shaft (18) is connected to the gear teeth (28) on the end face of the annular valve disc (17) by bevel gear (20); The number of the support plates (29) is two, and the two support plates (29) are arranged in the circumferential direction on the inner wall of the inlet transition section (9) of the intercooler; The number of sealing gaskets (19) is four, and all four sealing gaskets (19) are made of circular rubber.

2. The bypass system for an intercooled cycle gas turbine according to claim 1, characterized in that, The inlet transition section (9) and outlet transition section (10) of the intercooler are designed as two independent components, and the inlet transition section (9) and outlet transition section (10) of the intercooler are assembled by bolts.

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