20MW axial steam exhaust low-vacuum heat supply steam turbine
By designing a 20MW axial exhaust low-vacuum heating steam turbine, the steam from the main turbine directly enters the small turbine to perform work and then supply heat, solving the problem of poor heating economy of thermal power units and achieving efficient steam utilization and cost reduction.
Patent Information
- Application Number
- CN202511010859.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-22
- Publication Date
- 2025-10-28
AI Technical Summary
Existing thermal power units use a single-stage extraction steam desuperheating and pressure reduction method for heating, which leads to increased operating costs and poor heating economics.
Design a 20MW axial exhaust low-vacuum heating steam turbine. The steam from the main turbine enters the small turbine to do work and is then directly discharged to the heating system, avoiding the de-cooling and de-pressure process. Combine the butterfly valve structure and specific mechanical component design to optimize steam utilization.
It achieves a reduction in steam temperature and pressure, reduces plant power consumption, improves heating economy, and is easy to modify in traditional power plants, reducing exhaust steam loss and equipment costs.
Smart Images
Figure CN120845136A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of steam turbine technology, specifically to a 20MW axial exhaust low-vacuum heating steam turbine. Background Art
[0002] With the implementation of clean energy policies, the emissions from decentralized boiler room heating no longer meet environmental protection requirements, and are being replaced by centralized heating from power plants, which have better carbon emission indicators.
[0003] The thermal power units that have been put into operation were not designed with heating demand in mind, and can only use a certain stage of steam extraction for desuperheating and pressure reduction for heating. The desuperheating and pressure reduction process will increase operating costs, resulting in poor heating economy.
[0004] In summary, existing thermal power units use a single-stage extraction steam desuperheating and pressure reduction method for heating. The desuperheating and pressure reduction process increases operating costs and results in poor heating economics. Summary of the Invention
[0005] The purpose of this invention is to address the problem that existing thermal power units use a single-stage extraction steam desuperheating and pressure reduction method for heating, which increases operating costs and results in poor heating economics. Therefore, this invention provides a 20MW axial exhaust low-vacuum heating steam turbine.
[0006] The technical solution of the present invention is: a 20MW axial exhaust low vacuum heating steam turbine, comprising: a main steam turbine, wherein the main steam turbine has an exhaust port and an extraction port;
[0007] A small steam turbine, wherein a steam guide pipe is connected to the steam inlet of the small steam turbine, and a high-pressure main steam valve and a high-pressure regulating valve are sequentially arranged on the steam guide pipe. The high-pressure main steam valve is located on the side away from the small steam turbine, and the high-pressure regulating valve is located on the side closer to the small steam turbine.
[0008] The inlet of the steam guide pipe is connected to the exhaust port and extraction port of the main steam turbine, respectively, and the exhaust port of the small steam turbine is connected to the heating system.
[0009] Furthermore, the exhaust port of the small steam turbine is arranged axially.
[0010] Furthermore, both the high-pressure main steam valve and the high-pressure regulating valve are butterfly valves.
[0011] Furthermore, the small steam turbine includes a front bearing housing, a thrust support bearing, a high-pressure outer cylinder, a high-pressure end steam seal, a high-pressure inlet steam balance ring, a first-stage diaphragm, a second-stage diaphragm, a third-stage diaphragm, a fourth-stage diaphragm, a fifth-stage diaphragm, stationary blades, a rotor, moving blades, a low-pressure end steam seal, a low-pressure exhaust cylinder, a rear bearing housing, a support bearing, a front base frame, an integral support frame, a flexible plate, and a turning gear.
[0012] The front base frame is fixedly installed on the foundation of the small steam turbine, the rear bearing housing is installed inside the low-pressure exhaust cylinder, the low-pressure exhaust cylinder is flexibly connected to the flexible plate, and the front bearing housing is fixedly installed on the front base frame;
[0013] The high-pressure outer cylinder is mounted on the front bearing housing via a front cat claw support device. The moving blades are mounted on the corresponding flow passage of the rotor. The thrust support bearing is mounted on the front bearing housing, and the support bearing is mounted on the rear bearing housing. The rotor is supported on the thrust support bearing and the support bearing.
[0014] The high-pressure end steam seal is installed at the end of the high-pressure outer cylinder, and the rear steam seal is connected to the end of the low-pressure exhaust cylinder by bolts. The high-pressure inlet steam balance ring, the first-stage diaphragm, the second-stage diaphragm, the third-stage diaphragm, the fourth-stage diaphragm, and the fifth-stage diaphragm are all installed inside the high-pressure outer cylinder. The stationary blades are respectively installed on the first-stage diaphragm, the second-stage diaphragm, the third-stage diaphragm, the fourth-stage diaphragm, and the fifth-stage diaphragm.
[0015] The turning device is installed on top of the front bearing housing and is connected to the rotor inside the front bearing housing via the turning gear.
[0016] Furthermore, it also includes: a pre-start valve, installed on the top of the high-pressure outer cylinder, with the steam outlet of the pre-start valve connected to the interior of the high-pressure outer cylinder, and the steam inlet of the pre-start valve connected via a pipe to the area on the steam guide pipe located between the high-pressure main steam valve and the high-pressure regulating valve.
[0017] Furthermore, the high-pressure outer cylinder is a single-layer cylinder structure, which is connected to the low-pressure exhaust cylinder by vertical flange bolts.
[0018] Furthermore, the front bearing housing is the absolute dead point of the small steam turbine.
[0019] Furthermore, the relative dead point of the rotor is the working surface of the thrust disk of the thrust support bearing.
[0020] Compared with the prior art, the present invention has the following advantages:
[0021] 1. The 20MW axial exhaust low-vacuum heating steam turbine provided by this invention allows the main steam in the main turbine to enter the small turbine to do work. After doing work, the steam temperature and steam pressure will decrease. The steam from the small turbine is discharged to the heating system to heat the circulating water of the heating network to achieve the heating function. There is no need to deliberately de-temperature and de-pressure the steam. The small turbine can generate electricity when it is working, realizing the deep utilization of the medium-pressure exhaust steam of the main turbine while reducing the plant power consumption rate, thus making the heating economy better.
[0022] 2. The 20MW axial exhaust low-vacuum heating steam turbine provided by the present invention adopts an axial exhaust structure, and the exhaust steam is directly connected to the heating system horizontally, which reduces exhaust steam loss and makes the present invention easier to implement in the partial modification of traditional power plants. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the overall structure of the small steam turbine in this invention;
[0024] Figure 2 yes Figure 1 Top view;
[0025] Figure 3 yes Figure 1 A sectional view.
[0026] In the diagram: 1. High-pressure main steam valve; 2. High-pressure regulating valve; 3. Front bearing housing; 4. Thrust support bearing; 5. High-pressure outer cylinder; 6. High-pressure end steam seal; 7. High-pressure inlet steam balance ring; 8. First-stage diaphragm; 9. Second-stage diaphragm; 10. Third-stage diaphragm; 11. Fourth-stage diaphragm; 12. Fifth-stage diaphragm; 13. Stationary blade; 14. Rotor; 15. Moving blade; 16. Low-pressure end steam seal; 17. Low-pressure exhaust cylinder; 18. Pre-opening valve; 19. Rear bearing housing; 20. Support bearing; 21. Front base frame; 22. Integral support frame; 23. Steam guide pipe; 24. Flexible plate; 25. Turning gear; 26. Front cat claw support device; 27. Turning gear large gear. Detailed Implementation
[0027] Specific implementation method 1: Combination Figure 1 , Figure 2 This embodiment describes a main steam turbine (not shown in the figure) and a small steam turbine. The main steam turbine has an exhaust port and an extraction port. The steam inlet of the small steam turbine is connected to a steam guide pipe 23. A high-pressure main steam valve 1 and a high-pressure regulating valve 2 are sequentially arranged on the steam guide pipe 23. The high-pressure main steam valve 1 is located on the side away from the small steam turbine, and the high-pressure regulating valve 2 is located on the side closer to the small steam turbine. The inlet of the steam guide pipe 23 is connected to the exhaust port and extraction port of the main steam turbine, respectively. The exhaust port of the small steam turbine is connected to the heating system. In this embodiment, the exhaust port of the small steam turbine is specifically connected to the condenser in the heating system.
[0028] The 20MW axial exhaust low-vacuum heating steam turbine provided in this embodiment allows the main steam from the main turbine to enter the small turbine to perform work. After the work is done, the steam temperature and steam pressure will decrease. The steam from the small turbine is discharged to the heating system to heat the circulating water of the heating network to achieve the heating function. There is no need to deliberately de-temperature and de-pressure the steam. The small turbine can generate electricity when it is working, realizing the deep utilization of the medium-pressure exhaust steam of the main turbine while reducing the plant power consumption rate, thus making the heating economy better.
[0029] Specific implementation method 2: Combination Figure 1 , Figure 2This embodiment differs from Specific Embodiment 1 in that the exhaust port of the small steam turbine is arranged axially, and the exhaust steam is directly connected to the condenser horizontally. This reduces exhaust steam loss and makes the project easier to implement in the partial modification of a traditional power plant. Other components and connections are the same as in Specific Embodiment 1.
[0030] Specific implementation method three: Combination Figure 1 , Figure 2 This embodiment differs from Specific Embodiment 1 in that both the high-pressure main steam valve 1 and the high-pressure regulating valve 2 are butterfly valves. The butterfly valve structure avoids the problems of excessive weight and high cost associated with traditional plunger valves, thereby reducing costs. Other components and connections are the same as in Specific Embodiment 1.
[0031] Specific implementation method four: Combination Figures 1 to 3 This embodiment differs from specific embodiment one in that the small steam turbine includes a front bearing housing 3, a thrust support bearing 4, a high-pressure outer cylinder 5, a high-pressure end steam seal 6, a high-pressure inlet steam balance ring 7, a first-stage diaphragm 8, a second-stage diaphragm 9, a third-stage diaphragm 10, a fourth-stage diaphragm 11, a fifth-stage diaphragm 12, stationary blades 13, a rotor 14, moving blades 15, a low-pressure end steam seal 16, a low-pressure exhaust cylinder 17, a rear bearing housing 19, a support bearing 20, a front base frame 21, an integral support 22, a flexible plate 24, and a turning gear 25. The front base frame 21 is fixedly installed on the foundation of the small steam turbine. The rear bearing housing 19 is installed inside the low-pressure exhaust cylinder 17, which is flexibly connected to the flexible plate 24. The front bearing housing 3 is fixedly installed on the front base frame 21. The high-pressure outer cylinder 5 is installed on the front bearing housing 3 via a front claw support device 26. The moving blades 15 are installed... The thrust support bearing 4 is installed on the front bearing housing 3, and the support bearing 20 is installed on the rear bearing housing 19. The rotor 14 is supported on the thrust support bearing 4 and the support bearing 20. The high-pressure end steam seal 6 is installed at the end of the high-pressure outer cylinder 5. The rear steam seal is bolted to the end of the low-pressure exhaust cylinder 17. The high-pressure inlet steam balance ring 7, the first-stage diaphragm 8, the second-stage diaphragm 9, the third-stage diaphragm 10, the fourth-stage diaphragm 11, and the fifth-stage diaphragm 12 are all installed inside the high-pressure outer cylinder 5. The stationary blades 13 are respectively installed on the first-stage diaphragm 8, the second-stage diaphragm 9, the third-stage diaphragm 10, the fourth-stage diaphragm 11, and the fifth-stage diaphragm 12. The turning gear 25 is installed on the top of the front bearing housing 3 and is connected to the rotor 14 inside the front bearing housing 3 through the turning gear 27. The flow of the high-pressure outer cylinder 5 is arranged in a single flow pattern, and each section of the high-pressure end steam seal 6 is independent. Other components and connections are the same as in any of the specific embodiments one to three.
[0032] Specific Implementation Method Five: Combining Figures 1 to 3This embodiment differs from Specific Embodiment Four in that it further includes a pre-start valve 18, installed on the top of the high-pressure outer cylinder 5. The steam outlet of the pre-start valve 18 is connected to the interior of the high-pressure outer cylinder 5, and the steam inlet of the pre-start valve 18 is connected via a pipeline to the area on the steam guide pipe 23 located between the high-pressure main steam valve 1 and the high-pressure regulating valve 2. In this embodiment, the pre-start valve 18 can effectively reduce the pressure difference between the high-pressure outer cylinder 5 and the high-pressure main steam valve 1 and the high-pressure regulating valve 2, greatly shortening the opening time of the high-pressure main steam valve 1 and the high-pressure regulating valve 2, effectively improving valve working efficiency, and assisting the unit to start up quickly. Other components and connections are the same as in Specific Embodiment Four.
[0033] Specific Implementation Method Six: Combination Figures 1 to 3 This embodiment differs from Specific Embodiment Four in that the high-pressure outer cylinder 5 is a single-layer cylinder structure, connected to the low-pressure exhaust cylinder 17 via vertical flange bolts. The single-layer cylinder structure eliminates the need for a mating structure between the inner and outer cylinders (such as interlayers or positioning devices), resulting in fewer parts, a simpler overall processing flow, reduced complex sealing surface processing and assembly requirements, and lower precision control difficulties during manufacturing. Other components and connections are the same as in Specific Embodiment Four.
[0034] Specific implementation method seven: Combining Figures 1 to 3 This embodiment differs from Specific Embodiment Four in that the front bearing housing 3 is the absolute dead point of the small steam turbine. The connection between the small steam turbine and external pipelines (such as steam inlet pipe, extraction pipe, and exhaust pipe) needs to accommodate the thermal expansion of the equipment. As the absolute dead point, the fixed position of the front bearing housing 3 simplifies the expansion compensation design of the front-end pipelines (such as the high-pressure steam inlet pipe). Other components and connections are the same as in Specific Embodiment Four.
[0035] Specific implementation method eight: Combination Figures 1 to 3 This embodiment differs from specific embodiment four in that the relative dead point of rotor 14 is the working surface of the thrust disk of thrust support bearing 4. When the unit expands or contracts, rotor 14 expands or contracts towards the motor end from this surface point. Other components and connections are the same as in specific embodiment four.
[0036] The content of this invention is not limited to the above-described embodiments; a combination of one or more specific embodiments can also achieve the purpose of the invention.
Claims
1. A 20MW axial exhaust low-vacuum heating steam turbine, characterized in that, include: The main steam turbine has an exhaust port and an extraction port; A small steam turbine is provided with a steam inlet pipe (23) connected to the steam inlet. A high-pressure main steam valve (1) and a high-pressure regulating valve (2) are sequentially arranged on the steam inlet pipe (23). The high-pressure main steam valve (1) is located on the side away from the small steam turbine, and the high-pressure regulating valve (2) is located on the side close to the small steam turbine. The inlet of the steam pipe (23) is connected to the exhaust port and extraction port of the main steam turbine, respectively, and the exhaust port of the small steam turbine is connected to the heating system.
2. A 20MW axial exhaust low-vacuum heating steam turbine according to claim 1, characterized in that, The exhaust port of the small steam turbine is arranged axially.
3. A 20MW axial exhaust low-vacuum heating steam turbine according to claim 1, characterized in that, Both the high-pressure main steam valve (1) and the high-pressure regulating valve (2) are butterfly valves.
4. A 20MW axial exhaust low-vacuum heating steam turbine according to any one of claims 1-3, characterized in that, The small steam turbine includes a front bearing housing (3), a thrust support bearing (4), a high-pressure outer cylinder (5), a high-pressure end steam seal (6), a high-pressure inlet steam balance ring (7), a first-stage diaphragm (8), a second-stage diaphragm (9), a third-stage diaphragm (10), a fourth-stage diaphragm (11), a fifth-stage diaphragm (12), stationary blades (13), a rotor (14), moving blades (15), a low-pressure end steam seal (16), a low-pressure exhaust cylinder (17), a rear bearing housing (19), a support bearing (20), a front base frame (21), an integral support frame (22), a flexible plate (24), and a turning gear (25). The front base frame (21) is fixedly installed on the foundation of the small steam turbine, the rear bearing housing (19) is installed inside the low-pressure exhaust cylinder (17), the low-pressure exhaust cylinder (17) is flexibly connected to the flexible plate (24), and the front bearing housing (3) is fixedly installed on the front base frame (21). The high-pressure outer cylinder (5) is mounted on the front bearing housing (3) via the front cat claw support device (26), the moving blade (15) is mounted on the corresponding flow passage of the rotor (14), the thrust support bearing (4) is mounted on the front bearing housing (3), the support bearing (20) is mounted on the rear bearing housing (19), and the rotor (14) is supported on the thrust support bearing (4) and the support bearing (20). The high-pressure end steam seal (6) is installed at the end of the high-pressure outer cylinder (5), and the rear steam seal is connected to the end of the low-pressure exhaust cylinder (17) by bolts. The high-pressure steam inlet balance ring (7), the first-stage diaphragm (8), the second-stage diaphragm (9), the third-stage diaphragm (10), the fourth-stage diaphragm (11), and the fifth-stage diaphragm (12) are all installed inside the high-pressure outer cylinder (5). The stationary blades (13) are respectively installed on the first-stage diaphragm (8), the second-stage diaphragm (9), the third-stage diaphragm (10), the fourth-stage diaphragm (11), and the fifth-stage diaphragm (12). The turning device (25) is installed on top of the front bearing housing (3) and is connected to the rotor (14) inside the front bearing housing (3) via the turning gear (27).
5. A 20MW axial exhaust low-vacuum heating steam turbine according to claim 4, characterized in that, Also includes: A pre-start valve (18) is installed on the top of the high-pressure outer cylinder (5), and the steam outlet of the pre-start valve (18) is connected to the interior of the high-pressure outer cylinder (5). The steam inlet of the pre-start valve (18) is connected to the area on the steam guide pipe (23) between the high-pressure main steam valve (1) and the high-pressure regulating valve (2) through a pipeline.
6. A 20MW axial exhaust low-vacuum heating steam turbine according to claim 4, characterized in that, The high-pressure outer cylinder (5) is a single-layer cylinder structure, which is connected to the low-pressure exhaust cylinder (17) by vertical flange bolts.
7. A 20MW axial exhaust low-vacuum heating steam turbine according to claim 4, characterized in that, The front bearing housing (3) is the absolute dead point of the small steam turbine.
8. A 20MW axial exhaust low-vacuum heating steam turbine according to claim 4, characterized in that, The relative dead point of the rotor (14) is the working surface of the thrust disk of the thrust support bearing (4).