Vibration reduction device for valve rod of speed regulation valve of steam turbine

Abstract

The bottom end of a spring of a positioning sleeve is arranged in a base in a penetrating mode, the top end of the spring is arranged on the periphery of a guide sleeve in a sleeved mode and fixedly connected with the guide sleeve, a through hole is formed in the top face of an outer sleeve, the top end of the guide sleeve is arranged in the through hole in a penetrating mode, and threads meshed with each other are arranged on the outer wall of the base and the inner wall of the outer sleeve. According to the utility model, the spring and the guide sleeve are combined together, jackets with different heights are manufactured according to gaps between different models of steam turbine speed regulating valve rods and a cross arm, the whole vibration reduction device is arranged between the upper part of the valve rod and the cross arm, and after the vibration reduction device is arranged in place, the screw buckles of the jackets are reversely and loosely arranged, so that the valve rod is tightly pressed from the top; the spring in the device can compensate and eliminate the gap change problem caused by thermal expansion and reduce the self-excited vibration problem of the door rod under the acting force of the spring, the device is convenient to use, does not have technical limitation requirements, can quickly eliminate the vibration problem of the door rod, can also ensure the safety of people and equipment, and has very high practicability.

Description

Technical Field

[0001] The utility model belongs to the technical field of steam turbines, and particularly relates to a vibration reduction device for the valve rod of a steam turbine governing valve. Background Art

[0002] For steam turbines with cam groups used in thermal power plant generating units, especially for medium and small units, the governing valves mostly adopt the structure type of upper spring seats. During operation, due to the scouring and exciting action of high-pressure steam, the valve rod of the governing valve itself has high-frequency vibration. Due to the high-frequency vibration of the valve rod, the boss of the valve rod bracket of the governing valve often wears, resulting in an increase in the gap between the valve rod and the valve frame. When the unit adjusts the load, it is extremely easy to have a large load fluctuation phenomenon. Seriously, the valve rod of the governing valve may break, resulting in the shutdown of the unit. Moreover, when the unit runs and dumps the load or shuts down, it is impossible to reduce the unit load to zero, and the unit is prone to overspeed problems when the generator is switched on, seriously affecting the safe operation of the unit.

[0003] Due to the long-term existence of the valve rod vibration and wear problem, after the valve rod of the unit is replaced and the operation does not reach the overhaul period, problems such as valve rod wear and back cap falling off will occur. Moreover, after the spare parts are replaced, the operation period cannot be guaranteed, increasing the number of valve rod replacements, resulting in an increase in spare parts costs and high operating costs.

[0004] During the operation of steam turbine units using the cam group adjustment method at present, due to the scouring action of high-pressure steam, the high-frequency vibration of the valve rod of the governing valve itself cannot be eliminated, resulting in frequent wear of the boss of the valve rod bracket of the governing valve and the problem of increasing the gap between the valve rod and the valve frame. There is no effective solution. Generally, it is only replaced regularly or adjusted pads are added after the gap increases for treatment, and the effect is poor, and the operation period cannot be guaranteed. Content of the Utility Model

[0005] The purpose of the utility model is to provide a vibration reduction device for the valve rod of a steam turbine governing valve to reduce the high-frequency vibration problem existing in the operation of the valve rod of the steam turbine governing valve.

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

[0007] A vibration reduction device for the valve rod of a steam turbine governing valve includes an outer sleeve and a positioning sleeve disposed inside the outer sleeve. The positioning sleeve includes a base, a spring, and a guide sleeve. The bottom end of the spring is disposed inside the base, the top end of the spring is sleeved on the outer periphery of the guide sleeve and fixedly connected. A through hole is provided on the top surface of the outer sleeve, the top end of the guide sleeve is disposed inside the through hole, and mutually meshing threads are provided on the outer wall of the base and the inner wall of the outer sleeve.

[0008] In order to further implement the utility model, the diameter of the guide sleeve is smaller than the diameter of the spring, and the diameter of the spring is larger than the diameter of the through hole.

[0009] To further implement the present utility model, a tightness increasing pad is further provided on the bottom surface of the base.

[0010] To further implement the present utility model, a maintenance hole is provided on the side wall of the outer sleeve.

[0011] The beneficial effects of the present utility model compared with the prior art are as follows:

[0012] The present utility model combines a spring resistant to heat and a guide sleeve. According to the gap between the governing valve rod of a steam turbine of different models and the cross arm, outer sleeves of different heights are manufactured. The whole device of the present utility model is integrally installed between the top of the valve rod and the cross arm. After the vibration reduction device is installed in place, the screw thread of the outer sleeve is loosened in the reverse direction, and the valve rod is pressed tightly from the top. The spring inside the device can compensate and eliminate the change in gap caused by thermal expansion. Under the action of the spring, the self-excited vibration problem of the valve rod itself is reduced. It is convenient to use, has no technical limitation requirements, can quickly eliminate the vibration problem of the valve rod, and can also ensure the safety of personnel and equipment, with strong practicability.

[0013] In the present utility model, components are selected from materials with good high-temperature and deformation-resistant properties to avoid the influence on the vibration reduction effect caused by the decline of spring performance due to excessive temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a structural schematic diagram of the present utility model;

[0015] Figure 2 is Figure 1 a cross-sectional view of

[0016] Figure 3 is a structural disassembly diagram of the present utility model;

[0017] The meanings of the reference numerals are as follows: 1. Outer sleeve; 2. Positioning sleeve; 3. Base; 4. Spring; 5. Guide sleeve; 6. Through hole; 7. Thread; 8. Tightness increasing pad; 9. Maintenance hole; 10. Flange. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The present utility model will be further described below in conjunction with the drawings and specific embodiments.

[0019] As Figures 1-3As shown in the figure, a vibration reduction device for the valve rod of a steam turbine governing valve includes an outer sleeve 1 and a positioning sleeve 2 disposed within the outer sleeve 1. A maintenance hole 9 is provided on the side wall of the outer sleeve 1. The positioning sleeve 2 includes a base 3, a spring 4, and a guide sleeve 5. The bottom end of the spring 4 is inserted into the base 3. A flange 10 is provided on the outer periphery of the guide sleeve 5. The top end of the spring 4 is sleeved on the outer periphery of the guide sleeve 5 and fixedly connected. The top surface of the spring 4 contacts the bottom surface of the flange 10. A through hole 6 is provided on the top surface of the outer sleeve 1. The top end of the guide sleeve 5 is inserted into the through hole 6. Threads 7 that mesh with each other are provided on the outer wall of the base 3 and the inner wall of the outer sleeve 1. A tightening force increasing pad 8 is further provided on the bottom surface of the base 3.

[0020] Among them, the diameter of the guide sleeve 5 is smaller than the diameter of the spring 4, and the diameter of the spring 4 is larger than the diameter of the through hole 6.

[0021] According to the actual on-site situation, before installing the present utility model, the spring 5 is pre-tightened and compressed by using the threaded fit of the outer sleeve 1 and the positioning sleeve 2. After the device is in place, the outer sleeve 1 is loosened so that the top end of the guide sleeve 5 contacts the cross arm of the steam turbine cam group governing valve, that is, the outer sleeve 1 does not exert a compression function on the spring 4, and the spring 4 directly exerts force on the cross arm through the guide sleeve 5.

Claims

1. A device for reducing vibration of a turbine speed regulating valve stem, characterized in that: The invention comprises an outer sleeve (1) and a positioning sleeve (2) inserted into the outer sleeve (1), wherein the positioning sleeve (2) comprises a base (3), a spring (4) and a guide sleeve (5), wherein the bottom end of the spring (4) is inserted into the base (3), the top end of the spring (4) is sleeved on the outer circumference of the guide sleeve (5) and is fixedly connected thereto, a through hole (6) is provided on the top surface of the outer sleeve (1), the top end of the guide sleeve (5) is inserted into the through hole (6), and mutually meshing threads (7) are provided on the outer wall of the base (3) and the inner wall of the outer sleeve (1).

2. The device for reducing vibration of a turbine speed regulating valve stem according to claim 1, characterized in that: The diameter of the guide sleeve (5) is smaller than the diameter of the spring (4), and the diameter of the spring (4) is larger than the diameter of the through hole (6).

3. The device for reducing vibration of a turbine speed regulating valve stem according to claim 1 or 2, characterized in that: The bottom surface of the base (3) is also provided with a tightening force increasing pad (8).

4. The device for reducing vibration of a turbine speed regulating valve stem according to claim 3, characterized in that: A maintenance hole (9) is provided on the side wall of the outer casing (1).

5. The device for reducing vibration of a turbine speed regulating valve stem as claimed in claim 3, characterized in that: A flange (10) is provided on the outer periphery of the guide sleeve (5), and the top surface of the spring (4) contacts the bottom surface of the flange (10).

Images