Protection device for preventing low-pressure shaft seal temperature of steam turbine

Abstract

A protection device for preventing low temperature of a low-pressure shaft seal of a steam turbine belongs to the technical field of low-pressure cylinder shaft seal pipe heat preservation, aims to solve the problem of heat loss caused by exposure of a shaft seal air pipe, and comprises a first semicircular pipe, a second semicircular pipe, a first drainage component, a second drainage component, a first threaded gutter and a second threaded gutter. The first semicircular pipe and the second semicircular pipe are in butt joint to form a circular pipe, the first semicircular pipe and the second semicircular pipe are connected through a bolt, the first drainage assembly and the second drainage assembly are installed on the inner side of the first semicircular pipe and the inner side of the second semicircular pipe, and the first semicircular pipe and the second semicircular pipe are arranged on the shaft seal air pipe in a sleeving mode. Heat preservation of the shaft seal air pipe is achieved, the situation that steam carries water due to the fact that the shaft seal temperature is too low is avoided, the threat to the safety of a steam turbine rotor caused by thermal stress changes due to sudden change of lowering of the steam turbine rotor is effectively prevented, abnormal events are avoided, and long-period safe operation of a unit is guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of heat preservation of low-pressure cylinder shaft seal pipes, and in particular relates to a protective device for preventing low-pressure shaft seal temperature of a steam turbine. Background Art

[0002] After the steam from the low-pressure cylinder shaft seal main pipe is cooled by water spraying in the desuperheater, it is supplied to the low-pressure shaft seal steam chamber through four low-pressure shaft seal pipelines that pass through the condenser. The shaft seal steam in the condenser is easily cooled; because the steam inside the pipeline is cooled by the low-temperature exhaust steam when flowing through the exhaust area, the shaft seal air pipe is cooled down during normal operation or startup of the unit; if the turbine shaft seal steam temperature is lower than the overall temperature of the turbine, a large amount of water vapor will be generated, which will easily cause certain thermal stresses in the parts of each part of the turbine. In this case, relatively large friction is likely to occur between the parts in the turbine, thus affecting the service life of the turbine.

[0003] If the temperature of the shaft seal air pipe is too low during the startup of the unit, it will cause a mismatch with the temperature of the cylinder, which may easily cause excessive expansion difference during the turbine run-up process. In addition, too low shaft seal temperature can easily cause steam to carry water, leading to water hammer in the turbine, which seriously threatens the safe operation of the unit. The current insulation solution for the low-pressure cylinder shaft seal air pipe is to weld a sleeve on the low-pressure cylinder shaft seal air pipe. When the low-pressure cylinder shaft seal air pipe is damaged and needs to be repaired, the sleeve needs to be removed, which may easily cause further damage to the shaft seal air pipe.

[0004] In view of the above problems, a protective device is urgently needed to prevent the low-pressure shaft seal temperature of the steam turbine from being low, which is used to insulate the shaft seal air pipe and drain the condensate, and can be disassembled when the shaft seal air pipe needs maintenance. Utility Model Content

[0005] The problem to be solved by the utility model is that the shaft seal air pipe is exposed to the outside, causing heat loss. A protective device to prevent the low-pressure shaft seal temperature of a steam turbine from being low is proposed. To achieve the above purpose, the utility model is implemented through the following technical solutions:

[0006] A protective device for preventing a low-pressure shaft seal temperature of a steam turbine from being low, comprising: a first semicircular tube, a second semicircular tube, a first hydrophobic component, a second hydrophobic component, a first threaded water diversion groove, and a second threaded water diversion groove, wherein the first semicircular tube and the second semicircular tube are butted together to form a circular tube, the first semicircular tube and the second semicircular tube are connected by bolts, the first semicircular tube and the second semicircular tube are installed with the first hydrophobic component and the second hydrophobic component on the inner side, the first semicircular tube and the second semicircular tube are sleeved on the shaft seal air pipe, and the shaft seal air pipe passes through the second hydrophobic component, and the first hydrophobic component is arranged on the inner side There is a first threaded water diversion groove, and a second threaded water diversion groove is arranged on the outside of the second hydrophobic component. The first semicircular tube includes: a semicircular plate, a connecting part, a sealing part, a drainage part, a water seal groove, a groove and a connecting hole. Two connecting parts are arranged on the outside of the semicircular plate, and a plurality of connecting holes are arranged in a linear array on the connecting part. A sealing part is arranged on the upper end of the semicircular plate, and a drainage part is arranged on the lower end of the semicircular plate. The inside of the drainage part is connected to the second hydrophobic component, and a water seal groove is arranged in the drainage part. The inside of the semicircular plate is connected to the first hydrophobic component, and grooves for the shaft sealing air pipe to pass through are arranged on the sealing part and the drainage part.

[0007] Furthermore, the second semicircular tube and the first semicircular tube are mirror-image structures, the connecting holes of the second semicircular tube and the first semicircular tube are connected by bolts, and the docking surfaces of the second semicircular tube and the first semicircular tube are connected by a waterproof sealing gasket.

[0008] Furthermore, the water seal groove includes: a water inlet, a drain outlet, a first bending portion, and a second bending portion. The drain portion is provided with a water inlet on the inner side, the drain outlet is provided on the outer side of the drain portion, and the water seal groove is provided with a first bending portion and a second bending portion.

[0009] Furthermore, the inner side of the first hydrophobic component is arranged as a conical surface, and the wide opening of the conical surface is arranged on the inner side of the drainage portion, and the narrow opening of the conical surface is arranged on the inner side of the sealing portion.

[0010] Furthermore, the first hydrophobic component includes: a first hydrophobic block and a second hydrophobic block, the first hydrophobic block is connected to the inner side of the first semicircular tube, and the second hydrophobic block is connected to the inner side of the second semicircular tube.

[0011] Furthermore, the outer side of the second hydrophobic component is configured as a conical surface.

[0012] Furthermore, the second hydrophobic component includes: a third hydrophobic block and a fourth hydrophobic block, the third hydrophobic block is connected to the drain outlet of the first semicircular tube, and the fourth hydrophobic block is connected to the drain outlet of the second semicircular tube.

[0013] Furthermore, a sealing gasket is connected to the groove.

[0014] Furthermore, the first semicircular tube and the second semicircular tube are both provided with a remotely controllable thermocouple and a temperature sensor, and the thermocouple and the temperature sensor are both electrically connected to the centralized control room DCS equipment of the control room.

[0015] The beneficial effects of the utility model are:

[0016] The utility model provides a protective device to prevent the low-pressure shaft seal temperature of the steam turbine from being low, realizes the heat preservation of the shaft seal air pipe, avoids the steam carrying water caused by the shaft seal temperature being too low, effectively prevents the threat to the safety of the steam turbine rotor caused by the thermal stress change caused by the sudden change of the steam turbine rotor, avoids the occurrence of abnormal events, and ensures the long-term safe operation of the unit;

[0017] The utility model realizes self-drainage of condensed water through the first hydrophobic component and the second hydrophobic component, and prevents external cold air from entering the internal space of the first semicircular tube and the second semicircular tube when the device is placed vertically or horizontally through the first bending part and the second bending part, thereby reducing the temperature loss of the shaft sealing air pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the device of the utility model;

[0019] Figure 2 It is a front axonometric view of the first semicircular tube of the utility model;

[0020] Figure 3 This is a schematic diagram of the structure of the first semicircular tube of the utility model;

[0021] Figure 4 It is a structural schematic diagram of the second hydrophobic component of the utility model;

[0022] Figure 5 It is a front view of the first semicircular tube of the utility model;

[0023] Figure 6 for Figure 5 An enlarged view of region A;

[0024] Figure 7 It is an exploded view of the utility model;

[0025] Figure 8 It is a schematic diagram of the water seal of the utility model when placed horizontally;

[0026] Fig. 9 It is a schematic diagram of the water seal of the utility model when placed vertically;

[0027] Fig.10 This is a diagram showing the installation status of the utility model.

[0028] Description of reference numerals:

[0029] A first semicircular tube 1, a second semicircular tube 2, a first hydrophobic component 3, a second hydrophobic component 4, a semicircular plate 5, a connecting portion 6, a sealing portion 7, a drainage portion 8, a water seal groove 9, a groove 10, a first threaded water diversion groove 11, a second threaded water diversion groove 12, a connecting hole 13, a waterproof sealing gasket 14, a water inlet 15, a drainage outlet 16, a first bending portion 17, a second bending portion 18, a first hydrophobic block 19, a second hydrophobic block 20, a third hydrophobic block 21, and a fourth hydrophobic block 22. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model is further described in detail below in conjunction with the accompanying drawings and specific implementations. It should be understood that the specific implementations described herein are only used to explain the utility model and are not used to limit the utility model, that is, the specific implementations described are only part of the implementations of the utility model, not all of the specific implementations. The components of the specific implementations of the utility model described and shown in the drawings here can be arranged and designed in various different configurations, and the utility model can also have other implementations.

[0031] Therefore, the following detailed description of the specific embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents the selected specific embodiments of the present invention. Based on the specific embodiments of the present invention, all other specific embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0032] In order to further understand the content, features and functions of the utility model, the following specific implementation modes are given as examples and described in detail with the accompanying drawings as follows:

[0033] Example 1: Combination Figures 1 to 10To illustrate, a protective device for preventing the low-pressure shaft seal temperature of a steam turbine from being low in this embodiment includes: a first semicircular tube 1, a second semicircular tube 2, a first hydrophobic component 3, a second hydrophobic component 4, a first threaded water diversion groove 11 and a second threaded water diversion groove 12, the first semicircular tube 1 and the second semicircular tube 2 are connected to form a circular tube, the first semicircular tube 1 and the second semicircular tube 2 are connected by bolts, the first semicircular tube 1 and the second semicircular tube 2 are installed with the first hydrophobic component 3 and the second hydrophobic component 4 on the inner side, the first semicircular tube 1 and the second semicircular tube 2 are sleeved on the shaft seal air pipe, and the shaft seal air pipe passes through the second hydrophobic component 4, the first hydrophobic component 3 is provided with a first threaded water diversion groove 11 on the inner side, and the second hydrophobic component 4 is provided with a second threaded water diversion groove 12 on the outer side, the first semicircular tube 1 includes: a semicircular plate 5, a connecting portion 6, a sealing portion 7, a drainage portion 8, a water seal groove 9, a groove 10 and a connecting hole 13, the Two connecting parts 6 are arranged on the outer side of the semicircular plate 5, and a plurality of connecting holes 13 are arranged in a linear array on the connecting part 6. Two connecting parts 6 are arranged on the outer side of the semicircular plate 5, and a plurality of connecting holes 13 are arranged in a linear array on the connecting part 6. A sealing part 6 is arranged on the upper end of the semicircular plate 5, and a drainage part 7 is arranged on the lower end of the semicircular plate 5. The inner side of the drainage part 7 is connected with the second hydrophobic component 4, and a water seal groove 9 is arranged in the drainage part 7. The inner side of the semicircular plate 3 is connected with the first hydrophobic component 3. The sealing part 5 and the drainage part 6 are both provided with a groove 10 for the shaft sealing air pipe to pass through; wherein, the second semicircular tube 2 and the semicircular plate 5 of the first semicircular tube 1 are spliced ​​into a circular tube with a diameter of 133 mm, and the semicircular plate 5 is made of carbon steel. The second semicircular tube 2 and the groove 10 of the first semicircular tube 1 are spliced ​​into a circular hole for the shaft sealing air pipe with a diameter of 108 mm to pass through; the groove 10 is connected with a sealing gasket for sealing the connection with the shaft sealing air pipe;

[0034] The second semicircular tube 2 and the first semicircular tube 1 are mirror-image structures, the second semicircular tube 2 and the connecting hole 13 of the first semicircular tube 1 are connected by bolts, and the second semicircular tube 2 and the butt surface of the first semicircular tube 1 are connected by a waterproof sealing gasket 14; wherein the waterproof sealing gasket 14 is made of asbestos board, adjacent connecting holes 13 are spaced 500mm apart, and the aperture of the connecting hole 13 can insert a bolt with a diameter of 14mm, and a sealing ring connected to the bolt is arranged in the connecting hole 13;

[0035] The water seal groove 9 includes: a water inlet 15, a drain outlet 16, a first bent portion 17, and a second bent portion 18. The drain portion 8 is provided with a water inlet 15 on the inner side, and a drain outlet 16 on the outer side of the drain portion 8. The water seal groove 9 is provided with a first bent portion 17 and a second bent portion 18; the first bent portion 17 is used for water sealing when placed vertically, and the second bent portion 18 is used for water sealing when placed horizontally;

[0036] The inner side of the first hydrophobic component 3 is set as a conical surface, and the wide mouth of the conical surface is set on the inner side of the drainage part 7, and the narrow mouth of the conical surface is set on the inner side of the sealing part 7; the first hydrophobic component 3 includes: a first hydrophobic block 19 and a second hydrophobic block 20, the first hydrophobic block 19 is connected to the inner side of the first semicircular tube 1, and the second hydrophobic block 20 is connected to the inner side of the second semicircular tube 2;

[0037] The outer side of the second hydrophobic component 4 is set as a cone surface; the second hydrophobic component 4 includes: a third hydrophobic block 21 and a fourth hydrophobic block 22, the third hydrophobic block 21 is connected to the drain port 16 of the first semicircular tube 1, and the fourth hydrophobic block 22 is connected to the drain port 16 of the second semicircular tube 2;

[0038] The first semicircular tube 1 and the second semicircular tube 2 are both provided with a remotely controllable thermocouple and a temperature sensor, the thermocouple and the temperature sensor are both electrically connected to the DCS equipment in the control room, the temperature sensor is electrically connected to the input end of the DCS equipment in the control room, and the thermocouple is electrically connected to the output end of the DCS equipment in the control room. The temperature sensor is used to monitor that the temperature of the first semicircular tube 1 and the second semicircular tube 2 is not lower than 121°C. If the temperature is lower than 121°C, the thermocouple is controlled to heat the first semicircular tube 1 and the second semicircular tube 2;

[0039] The utility model connects the first semicircular tube 1 and the second semicircular tube 2 to form a circular tube, and the first semicircular tube 1 and the second semicircular tube 2 are connected by bolts, so as to achieve heat preservation of the shaft sealing air pipe, and the first hydrophobic component 3 and the second hydrophobic component 4 are installed on the inner sides of the first semicircular tube 1 and the second semicircular tube 2, the first semicircular tube 1 and the second semicircular tube 2 are sleeved on the shaft sealing air pipe, and the shaft sealing air pipe passes through the second hydrophobic component 4, the first hydrophobic component 3 is provided with a first threaded water diversion groove 11 on the inner side, and the second hydrophobic component 4 is provided with a second threaded water diversion groove 12 on the outer side, so as to achieve self-drainage of condensed water between the shaft sealing air pipe and the first semicircular tube 1 and the second semicircular tube 2, and prevent external cold air from entering the internal space of the first semicircular tube 1 and the second semicircular tube 2 through the first bending portion 17 and the second bending portion 18, thereby reducing the temperature loss of the shaft sealing air pipe.

[0040] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including a..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0041] Although the present application has been described above with reference to specific embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the various features in the specific embodiments disclosed in the present application may be used in combination with each other in any manner, and the fact that these combinations are not exhaustively described in this specification is only for the sake of omitting space and saving resources. Therefore, the present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A protective device for preventing low-pressure shaft seal temperature of a steam turbine, characterized in that: include: A first semicircular tube (1), a second semicircular tube (2), a first hydrophobic component (3), a second hydrophobic component (4), a first threaded water diversion groove (11) and a second threaded water diversion groove (12); the first semicircular tube (1) and the second semicircular tube (2) are butt-jointed to form a circular tube; the first semicircular tube (1) and the second semicircular tube (2) are connected by bolts; the first hydrophobic component (3) and the second hydrophobic component (4) are installed on the inner sides of the first semicircular tube (1) and the second semicircular tube (2); the first semicircular tube (1) and the second semicircular tube (2) are sleeved on the shaft sealing air pipe, and the shaft sealing air pipe passes through the second hydrophobic component (4); the first hydrophobic component (3) is provided with a first threaded water diversion groove (11) on the inner side, and the second hydrophobic component (4) is provided with a second threaded water diversion groove (12) on the outer side. A threaded water diversion groove (12), wherein the first semicircular tube (1) comprises: a semicircular plate (5), a connecting portion (6), a sealing portion (7), a drainage portion (8), a water seal groove (9), a groove (10) and a connecting hole (13), wherein two connecting portions (6) are arranged on the outer side of the semicircular plate (5), and a plurality of connecting holes (13) are arranged in a linear array on the connecting portion (6), a sealing portion (7) is arranged on the upper end of the semicircular plate (5), a drainage portion (8) is arranged on the lower end of the semicircular plate (5), a second hydrophobic component (4) is connected to the inner side of the drainage portion (8), a water seal groove (9) is arranged in the drainage portion (8), a first hydrophobic component (3) is connected to the inner side of the semicircular plate (5), and a groove (10) for the shaft sealing air pipe to pass through is arranged on both the sealing portion (7) and the drainage portion (8).

2. A protection device for preventing low-pressure shaft seal temperature of a steam turbine according to claim 1, characterized in that: The second semicircular tube (2) and the first semicircular tube (1) are of mirror-image structure; the second semicircular tube (2) and the connecting hole (13) of the first semicircular tube (1) are connected by bolts; and the butt joint surfaces of the second semicircular tube (2) and the first semicircular tube (1) are connected by a waterproof sealing gasket (14).

3. A protection device for preventing low-pressure shaft seal temperature of a steam turbine according to claim 2, characterized in that: The water seal groove (9) comprises: a water inlet (15), a drainage outlet (16), a first bent portion (17), and a second bent portion (18); the drainage portion (8) is provided with a water inlet (15) on the inner side, the drainage portion (8) is provided with a drainage outlet (16) on the outer side, and the water seal groove (9) is provided with a first bent portion (17) and a second bent portion (18).

4. A protection device for preventing low-pressure shaft seal temperature of a steam turbine according to claim 2, characterized in that: The inner side of the first hydrophobic component (3) is arranged as a conical surface, and the wide opening of the conical surface is arranged on the inner side of the drainage portion (8), and the narrow opening of the conical surface is arranged on the inner side of the sealing portion (7).

5. A protection device for preventing low-pressure shaft seal temperature of a steam turbine according to claim 2, characterized in that: The first hydrophobic component (3) comprises: a first hydrophobic block (19) and a second hydrophobic block (20); the first hydrophobic block (19) is connected to the inner side of the first semicircular tube (1); and the second hydrophobic block (20) is connected to the inner side of the second semicircular tube (2).

6. A protection device for preventing low-pressure shaft seal temperature of a steam turbine according to claim 2, characterized in that: The outer side of the second hydrophobic component (4) is arranged to be a conical surface.

7. A protection device for preventing low-pressure shaft seal temperature of a steam turbine according to claim 2, characterized in that: The second hydrophobic component (4) comprises: a third hydrophobic block (21) and a fourth hydrophobic block (22); the third hydrophobic block (21) is connected to the drain outlet (16) of the first semicircular tube (1), and the fourth hydrophobic block (22) is connected to the drain outlet (16) of the second semicircular tube (2).

8. A protection device for preventing low-pressure shaft seal temperature of a steam turbine according to claim 1, characterized in that: A sealing gasket is connected to the groove (10).

9. A protection device for preventing low-pressure shaft seal temperature of a steam turbine according to claim 2, characterized in that: The first semicircular tube (1) and the second semicircular tube (2) are both provided with a remotely controllable thermocouple and a temperature sensor, and the thermocouple and the temperature sensor are both electrically connected to the centralized control room DCS equipment in the control room.

Images