Water spraying cooling device for exhaust hood of steam turbine

Abstract

The utility model relates to the technical field of steam turbines, in particular to a steam turbine exhaust hood water spray cooling device which comprises an exhaust hood, a water spray cooling mechanism is arranged on the right side in the exhaust hood and comprises an annular water spray pipe and a water spray ring, and the water spray ring is embedded in the exhaust hood. An annular water spraying pipe of a semicircular structure is arranged on the upper side of the annular face of the exhaust hood, the annular water spraying pipe is connected with a water spraying ring through multiple sets of water inlet connecting pipes, a water conveying pipe is connected to the annular water spraying pipe, multiple sets of nozzles are assembled on the inner annular face of the water spraying ring, and a circle of buffering check rings are arranged on the inner side of the water spraying ring at intervals. Cooling water can be sprayed into the exhaust hood through the multiple sets of sprayers, the exhaust hood is cooled, damage to the exhaust hood caused by high temperature is prevented, meanwhile, water flow sprayed out of the sprayers can be effectively dispersed through the buffering check ring of the arc-shaped structure, direct contact between the cooling water and impeller blades is avoided, and the service life of the impeller blades is prolonged. And the erosion effect on the impeller blades is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of steam turbines, in particular to a water spraying and cooling device for a steam turbine exhaust cylinder. Background Art

[0002] A steam turbine is a power machine that converts steam energy into mechanical energy, and the exhaust cylinder is one of the key components that discharges high-temperature and high-pressure steam. During the operation of the steam turbine, the high-temperature and high-pressure steam flows through the exhaust cylinder and is discharged into the atmosphere, completing the first stage of power output. The operating principle of the exhaust cylinder is similar to that of the cylinder, but because the exhaust steam temperature is very high, it is easy to cause thermal stress and thermal fatigue in the exhaust cylinder. In severe cases, it will cause deformation, cracking and other problems in the exhaust cylinder, affecting the normal operation of the steam turbine and even causing damage to the equipment.

[0003] In order to ensure the operating stability and extend the service life of the exhaust cylinder, a water spray cooling device is required, which can effectively reduce the temperature of the exhaust cylinder and prevent high temperature from damaging the exhaust cylinder. The principle of water spray cooling is to absorb the heat of the exhaust cylinder by spraying cooling water into the exhaust cylinder, thereby reducing the temperature of the exhaust cylinder. At the same time, water vapor will also mix with steam, thereby increasing the output power of the exhaust cylinder and improving the thermal efficiency of the steam turbine.

[0004] However, when the existing water spray cooling device is in use, cooling water is directly sprayed into the exhaust cylinder, and the sprayed cooling water will directly contact the last-stage impeller blades of the steam turbine, causing the local temperature of the last-stage impeller blades to drop sharply, causing the internal stress of the last-stage impeller blades to change, which will cause the mechanical structure strength of the impeller blades to decrease over a long period of time, affecting the normal operation of the steam turbine, and causing a certain erosion effect on the last-stage impeller blades, shortening the service life of the steam turbine. Utility Model Content

[0005] In view of the existing deficiencies, the utility model provides a steam turbine exhaust cylinder water spray cooling device, which solves the problems raised in the above background technology.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] A steam turbine exhaust cylinder water spray cooling device comprises a water spray cooling mechanism arranged on the right side of the exhaust cylinder, the water spray cooling mechanism comprises a delivery pipe, an annular water spray pipe, a water inlet connecting pipe, a water spray ring, a buffer retaining ring and a nozzle, the water spray ring is embedded in the exhaust cylinder, the semicircular annular water spray pipe is arranged on the upper side of the ring surface of the exhaust cylinder, the annular water spray pipe is connected to the water spray ring through multiple groups of water inlet connecting pipes, the annular water spray pipe is connected to the delivery water pipe, and the end of the delivery water pipe is connected to an external water pump, multiple groups of nozzles are installed on the inner ring surface of the water spray ring, a circle of buffer retaining rings are arranged at intervals on the inner side of the water spray ring, and the buffer retaining ring is located on the outer side of the nozzle and is arranged at intervals therefrom.

[0008] Furthermore, the cross section of the buffer retaining ring is an arc-shaped structure protruding outward, and the protruding side thereof faces the nozzle.

[0009] Furthermore, the buffer retaining ring is fixedly connected to the water spray ring through multiple groups of fixed support rods, and the multiple groups of fixed support rods are staggered with the multiple groups of spray heads.

[0010] Furthermore, the water spray ring is composed of a ring body A and a ring body B, and the ring body A and the ring body B are fixedly connected by bolts. A circle of flow channels are opened inside the ring body A and the ring body B. A sealing groove is opened inside the connection between the ring body A and the ring body B, and a sealing gasket is installed in the sealing groove.

[0011] Furthermore, a circle of annular side plates are fixedly provided on the outer sides of the ring bodies A and B, and the side plates are fixedly connected to the exhaust cylinder by bolts.

[0012] Furthermore, a positioning groove is provided on the inner wall of the exhaust cylinder, and the outer ring surface of the water spray ring is inserted into the positioning groove.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] 1. The utility model can spray cooling water into the exhaust cylinder through the multiple groups of nozzles to cool the exhaust cylinder and prevent high temperature from damaging the exhaust cylinder. At the same time, the buffer retaining ring with an arc structure can effectively disperse the water flow sprayed from the nozzle, avoid direct contact between the cooling water and the impeller blades, and reduce the erosion effect on the impeller blades.

[0015] 2. The cross section of the buffer retaining ring in the utility model is an arc-shaped structure protruding outward, and its protruding side faces the nozzle. The arc-shaped structure of the buffer retaining ring can effectively disperse the water flow sprayed from the nozzle. When the water flow hits the arc-shaped surface, it will be evenly guided to the surroundings to prevent it from directly rushing to the last-stage impeller blade of the steam turbine, reducing the direct impact and erosion of the water flow on the impeller blade, and playing a good buffering effect.

[0016] 3. The water spray ring in the utility model adopts a split design of ring body A and ring body B, which is convenient for installation and disassembly of the water spray ring and improves the convenience of installation, disassembly and maintenance. A sealing groove is provided inside the connection between ring body A and ring body B, and a sealing gasket is installed in the sealing groove. The sealing gasket ensures the sealing performance of the connection, prevents cooling water from leaking under high pressure, and thus ensures the normal operation and safety of the water spray cooling device.

[0017] 4. A ring-shaped side plate is fixed on the outside of the ring body A and the ring body B, and the side plate is fixedly connected to the exhaust cylinder by bolts. The ring-shaped side plate is tightly connected to the exhaust cylinder by bolts, providing a stable support for the water spray ring, improving the installation stability of the water spray ring, and at the same time, the bolt connection reduces the installation difficulty and improves the convenience of installation and disassembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0019] Figure 2 It is a schematic diagram of the internal structure of the exhaust cylinder in the utility model.

[0020] Figure 3 It is a front cross-sectional view of the water spray cooling mechanism in the utility model.

[0021] Figure 4 It is a partial structural schematic diagram of the water spray cooling mechanism in the utility model.

[0022] Figure 5 It is a schematic diagram of the disassembled structure of the water spray ring in the utility model.

[0023] In the figure: 1. exhaust cylinder; 2. water spray cooling mechanism; 21. water delivery pipe; 22. annular water spray pipe; 23. water inlet connecting pipe; 24. water spray ring; 241. ring body A; 242. ring body B; 243. flow channel; 244. sealing gasket; 25. buffer retaining ring; 26. side plate; 27. positioning slot; 28. nozzle; 29. ​​fixing support rod. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] Example:

[0026] like Figures 1 to 5As shown, a steam turbine exhaust cylinder water spray cooling device comprises a water spray cooling mechanism 2 arranged on the right side of the exhaust cylinder 1, the water spray cooling mechanism 2 comprises a delivery pipe 21, an annular water spray pipe 22, a water inlet connecting pipe 23, a water spray ring 24, a buffer retaining ring 25 and a nozzle 28, the water spray ring 24 is embedded in the exhaust cylinder 1, the semicircular annular water spray pipe 22 is arranged on the upper side of the ring surface of the exhaust cylinder 1, the annular water spray pipe 22 is connected to the water spray ring 24 through multiple groups of water inlet connecting pipes 23, the annular water spray pipe 22 is connected to the delivery pipe 21, and the end of the delivery pipe 21 is connected to an external water pump, the water spray ring 24 A plurality of groups of nozzles 28 are mounted on the inner ring surface, a circle of buffer retaining rings 25 are arranged at intervals on the inner side of the water spray ring 24, and the buffer retaining rings 25 are located on the outer side of the nozzles 28 and are arranged at intervals therefrom. This design solves the problem that when the existing water spray cooling device is in use, cooling water is directly sprayed into the exhaust cylinder 1, and the sprayed cooling water will directly contact the last-stage impeller blades of the steam turbine, causing the local temperature of the last-stage impeller blades to drop sharply, causing the internal stress of the last-stage impeller blades to change, which will cause the mechanical structure strength of the impeller blades to decrease over a long period of time, affecting the normal operation of the steam turbine, and causing a certain erosion effect on the last-stage impeller blades, shortening the service life of the steam turbine.

[0027] The cross section of the buffer retaining ring 25 is an arc-shaped structure convex outward, and its convex side faces the nozzle 28. The arc-shaped structure of the buffer retaining ring 25 can effectively disperse the water flow sprayed from the nozzle 28. When the water flow hits the arc-shaped surface, it will be evenly guided to the surroundings to prevent it from directly rushing to the last-stage impeller blade of the steam turbine, reducing the direct impact and erosion of the water flow on the impeller blade, and playing a good buffering effect.

[0028] The buffer retaining ring 25 is fixedly connected to the water spray ring 24 through multiple sets of fixed support rods 29, and the multiple sets of fixed support rods 29 are staggered with the multiple sets of nozzles 28. The buffer retaining ring 25 is tightly connected to the water spray ring 24 through multiple sets of fixed support rods 29, ensuring that the buffer retaining ring 25 will not shift or loosen during use, and ensuring the installation stability of the buffer retaining ring 25.

[0029] The water spray ring 24 is composed of a ring body A241 and a ring body B242, which are fixedly connected by bolts, and a circle of flow channel 243 is provided inside the ring body A241 and the ring body B242, and a sealing groove is provided inside the connection between the ring body A241 and the ring body B242, and a sealing gasket 244 is installed in the sealing groove. The sealing gasket 244 ensures the sealing performance of the connection, prevents the cooling water from leaking under high pressure, and thus ensures the normal operation and safety of the water spray cooling device. The water spray ring 24 adopts a split design of the ring body A241 and the ring body B242, which is convenient for installation and disassembly of the water spray ring 24, and improves the convenience of installation, disassembly and maintenance.

[0030] The outer sides of the ring bodies A241 and B242 are fixed with an annular side plate 26, which is fixedly connected to the exhaust cylinder 1 by bolts. The annular side plate 26 is tightly connected to the exhaust cylinder 1 by bolts, providing a stable support for the water spray ring 24, improving the installation stability of the water spray ring 24, and reducing the installation difficulty through bolt connection, and improving the convenience of installation and disassembly.

[0031] The inner wall of the exhaust cylinder 1 is provided with a positioning slot 27, and the outer ring surface of the water spray ring 24 is inserted into the positioning slot 27. The positioning slot 27 can be engaged with the outer ring surface of the water spray ring 24, ensuring that the water spray ring 24 can be accurately installed at a predetermined position, avoiding deviations during the installation process, improving the stability and convenience of the installation of the water spray ring 24, and ensuring the stable operation of the water spray cooling device.

[0032] The working principle of the steam turbine exhaust cylinder water spray cooling device is as follows: first, the external water pump is started, and the cooling water is pumped into the annular water spray pipe 22 through the delivery water pipe 21. The annular water spray pipe 22 is connected to the water spray ring 24 through multiple sets of water inlet connecting pipes 23, so that the cooling water is evenly transported to a circle of flow channels 243 inside the water spray ring 24. Multiple sets of nozzles 28 installed on the inner ring surface of the water spray ring 24 will spray the cooling water into the exhaust cylinder 1 to cool the exhaust cylinder 1. When the cooling water is sprayed from the nozzle 28, the arc structure of the buffer retaining ring 25 can effectively disperse the water flow to prevent it from directly rushing to the last-stage impeller blade of the steam turbine, thereby avoiding the problem of internal stress changes of the last-stage impeller blade caused by the sudden drop in temperature, protecting the impeller blade from erosion, and extending the service life of the steam turbine.

[0033] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A steam turbine exhaust cylinder water spray cooling device, characterized in that: It comprises a water spray cooling mechanism (2) arranged on the right side inside the exhaust cylinder (1); The water spray cooling mechanism (2) comprises a water delivery pipe (21), an annular water spray pipe (22), a water inlet connecting pipe (23), a water spray ring (24), a buffer retaining ring (25) and a nozzle (28). The water spray ring (24) is embedded in the exhaust cylinder (1). The annular water spray pipe (22) with a semicircular structure is arranged on the upper side of the annular surface of the exhaust cylinder (1). The annular water spray pipe (22) is connected to the water spray ring (24) through multiple groups of water inlet connecting pipes (23). The annular water spray pipe (22) is connected to the water delivery pipe (21), and the end of the water delivery pipe (21) is connected to an external water pump. Multiple groups of nozzles (28) are installed on the inner annular surface of the water spray ring (24). A circle of buffer retaining rings (25) are arranged at intervals on the inner side of the water spray ring (24), and the buffer retaining rings (25) are located outside the nozzles (28) and arranged at intervals therefrom.

2. The steam turbine exhaust cylinder water spray cooling device according to claim 1 is characterized in that: The cross section of the buffer retaining ring (25) is an arc-shaped structure that bulges outward, and the bulging side thereof faces the spray head (28).

3. The steam turbine exhaust cylinder water spray cooling device according to claim 2 is characterized in that: The buffer retaining ring (25) is fixedly connected to the water spray ring (24) via multiple groups of fixed support rods (29), and the multiple groups of fixed support rods (29) are staggered with the multiple groups of spray heads (28).

4. The steam turbine exhaust cylinder water spray cooling device according to claim 1, characterized in that: The water spray ring (24) is composed of a ring body A (241) and a ring body B (242), wherein the ring body A (241) and the ring body B (242) are fixedly connected by bolts, and a circle of flow channel (243) is provided inside the ring body A (241) and the ring body B (242), and a sealing groove is provided inside the connection between the ring body A (241) and the ring body B (242), and a sealing gasket (244) is installed in the sealing groove.

5. The steam turbine exhaust cylinder water spray cooling device according to claim 4 is characterized in that: An annular side plate (26) is fixedly provided on the outer sides of the ring body A (241) and the ring body B (242), and the side plate (26) is fixedly connected to the exhaust cylinder (1) by bolts.

6. The steam turbine exhaust cylinder water spray cooling device according to claim 1, characterized in that: The inner wall of the exhaust cylinder (1) is provided with a positioning groove (27), and the outer ring surface of the water spray ring (24) is inserted into the positioning groove (27).

Images