Overhaul device special for steam turbine valve direct connection operating seat

Abstract

The invention provides a special overhauling device for a steam turbine valve direct-connection operating seat, which is a device special for overhauling a power plant direct-connection operating seat, and can assist overhauling personnel in quickly disassembling and reassembling the operating seat, so that convenience is brought to the overhauling work of the operating seat, the overhauling time is saved, and the overhauling work efficiency is improved. And safe and reliable maintenance work is ensured. The device is simple in structure and low in manufacturing cost, assists in completing spring force released in the disassembling process through a simple mechanical structure, meanwhile, can quickly help a disc spring set to be firmly and conveniently reassembled, greatly shortens the overhaul period, reduces waste of manpower and energy, and improves safety and timeliness in the overhaul process.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal power generation, and particularly relates to a special maintenance device for directly connecting a steam turbine valve to a control seat. Background Art

[0002] At present, most of the valve actuators of thermal power steam turbine generator sets are composed of an oil motor and a control seat. The control seats of the valve actuators of some generator sets introduced from Mitsubishi of Japan are hinge-type lever structures, and cylindrical springs are used to provide spring force. This structure has many drawbacks. During the opening and closing process of the valve, it is often easy to cause valve jamming or breakage of the control seat connecting rod, bringing serious hidden dangers to the safe operation of the unit. With the continuous development of technology, direct-connection actuators have gradually replaced hinge-type lever structures. All thermal power units above 660 MW currently use direct-connection actuators, and some 350 MW thermal power units have also completed the transformation of the direct-connection structure. As shown in the attached Figure 1 The direct-connection control seat mainly consists of an upper end cover, a housing, a disc spring group, a slide carriage assembly, a displacement transmission assembly, a guide roller assembly, and a flange connection assembly, etc. This structure is connected to the valve and the oil motor, mainly providing spring force for the valve to ensure tight closing of the valve and ensure safe and quick shutdown of the unit. During normal maintenance of the unit or when the control seat needs to be repaired due to temporary problems, it is often necessary to quickly disassemble and assemble the control seat. Under the limited conditions of the power plant, during the disassembly process of this type of control seat structure, due to the pre-compressed spring of the disc spring group, when disassembling the upper cover of the control seat, it is often easy to generate a large impact force due to the sudden release of the compressed spring, bringing danger to the maintenance personnel. Even though long bolts are used for protection between the spring end cover and the housing, it is still difficult to disassemble due to the existence of spring force. Moreover, during the reassembly process after disassembly, the requirement of the spring pre-compression amount also makes the reassembly work consume a lot of manpower and time, which is not conducive to the maintenance work of the control seat and affects the maintenance period of the unit. Summary of the Invention

[0003] The present invention is a special maintenance device for directly connecting a steam turbine valve to a control seat, which is a device specifically used for maintaining the direct-connection control seat in a power plant. This device can assist maintenance personnel in quickly disassembling and assembling the control seat, bringing convenience to the maintenance work of the control seat, saving maintenance time, improving the efficiency of the maintenance work, and ensuring the safety and reliability of the maintenance work. The present invention not only has a simple structure but also a low manufacturing cost. Through a simple mechanical structure, it assists in completing the release of the spring force during the disassembly process, and at the same time can quickly and conveniently reassemble the disc spring group firmly, greatly shortening the maintenance cycle, reducing the waste of manpower and energy, and improving the safety and timeliness during the maintenance process.

[0004] The present invention provides a special overhaul device for a direct-connected control seat of a steam turbine valve, which specifically includes: a lifting ring (1), a lifting and installing connecting rod (2), an upper limit nut (3), an upper limit gasket (4), a lower limit gasket (5), a lower limit nut (6), and a seating platform (7).

[0005] Optionally, for the transformation of the direct connection structure, the actuator control seat after transformation is as shown in the appendix Figure 1 As shown, the direct-connected control seat mainly consists of an upper end cover, a housing, a disc spring group, a slide carriage assembly, a displacement transmission assembly, a guide roller assembly, and a flange connection assembly, etc. This structure is connected to the valve and the oil motor, mainly providing spring force for the valve to ensure the tight closure of the valve and guarantee the safe and quick shutdown of the unit.

[0006] The beneficial effects are as follows: 1. The present invention is a special overhaul device for a direct-connected control seat of a steam turbine valve, which can effectively help maintenance personnel quickly disassemble and reinstall the control seat.

[0007] 2. The present invention makes the direct-connected control seat safe and reliable during the overhaul process, and will not cause personal injuries due to the sudden release of huge spring force.

[0008] 3. The present invention effectively improves the overhaul period and avoids the time waste caused by the disassembly and reinstallation work during the limited maintenance period of the unit.

[0009] 4. The present invention not only has a simple structure, low cost, strong practicability and high reliability.

[0010] 5. The present invention reduces the professional difficulty of overhauling the control seat and is more conducive to the maintenance work of the daily maintenance personnel in the power plant. Brief Description of the Drawings

[0011] Figure 1 Shows the structure diagram of the direct-connected control seat according to an embodiment of the present invention; Figure 2 Shows the schematic diagram of the overhaul device disassembling the control seat according to an embodiment of the present invention; Figure 3 Shows the schematic diagram of the overhaul device reinstalling the control seat according to an embodiment of the present invention; Figure 4 Shows the structure diagram of the special overhaul device for the direct-connected control seat of the steam turbine valve according to an embodiment of the present invention.

[0012] List of Reference Numerals 1. Lifting ring; 2. Lifting and installing connecting rod; 3. Upper limit nut; 4. Upper limit gasket; 5. Lower limit gasket; 6. Lower limit nut; 7. Seating platform. Detailed Embodiments

[0013] In order to make the objectives, solutions, and advantages of the technical solution of the present invention clearer, the following will clearly and completely describe the technical solution of the embodiments of the present invention in conjunction with the drawings of the specific embodiments of the present invention.

[0014] Embodiment 1: Please refer to Figures 1 to 4 as shown in The present invention is a special maintenance device for directly connecting the steam turbine valve to the operating seat, mainly used for the special maintenance of the directly connected operating seat as shown in Figure (1). When disassembling Figure (1), the displacement transmission assembly, guide roller assembly, flange connection assembly and other components on the operating seat can be removed first, and the oil motor piston rod can be pulled out. After initially removing the above components, as shown in Figure (2) of the appendix, at this time, the lifting ring (1), lifting connecting rod (2), upper limit nut (3), and upper limit gasket (4) of the special maintenance device of the present invention are assembled and inserted through the central hole of the upper end cover of the operating seat. When the lifting connecting rod (2) extends out of the carriage assembly position, the lower limit gasket (5) and lower limit nut (6) are tightened at the bottom end of the carriage assembly. After installation, the limit distance for disassembling the upper end cover can be adjusted by externally rotating the upper limit nut (3) and upper limit gasket (4). At this time, the maintenance personnel can directly disassemble the connecting bolts between the upper end cover and the housing of the operating seat. Due to the presence of the upper limit nut (3), there is no need to worry about the sudden release force caused by the spring being compressed. When the disc spring group is completely in a free state by rotating the upper limit nut (3) and upper limit gasket (4), the upper limit nut (3) is locked, and the disc spring assembly and the carriage assembly are lifted out as a whole by the crane through the lifting ring (1), and then placed on the seating platform (7), as shown in Figure (2) of the appendix. Then, the lower limit gasket (5) and lower limit nut (6) are removed, and the disc spring and the carriage assembly can be maintained.

[0015] Embodiment 2: Based on Embodiment 1, as Figures 3 - 4 shown, when the operating seat needs to be reinstalled, the carriage assembly is also first placed on the seating platform (7), the disc spring group is stably placed on the carriage assembly, and then the carriage assembly and the disc spring group are fixed as a whole by using the lifting ring (1), lifting connecting rod (2), upper limit nut (3), upper limit gasket (4), lower limit gasket (5), and lower limit nut (6). Similarly, as shown in Figure (3), at this time, the disc spring assembly and the carriage assembly are integrally installed into the housing by using a crane. The bolts between the upper end cover and the housing of the operating seat are tightened by using the upper limit nut (3) and upper limit gasket (4) to complete the reinstallation work.

Claims

1. A special maintenance device for a steam turbine valve directly connected to a control seat, comprising: A lifting ring (1), a lifting connecting rod (2), an upper limit nut (3), an upper limit washer (4), a lower limit washer (5), a lower limit nut (6), and a seating platform (7).

2. A special maintenance device for a steam turbine valve directly connected to a control seat as claimed in claim 1, characterized in that: First remove the displacement transmission assembly, guide roller assembly, flange connection assembly and other parts on the operating seat, and pull out the oil motor piston rod.

3. A special maintenance device for a steam turbine valve directly connected to a control seat as claimed in claim 1, characterized in that: The lifting ring (1), lifting connecting rod (2), upper limit nut (3) and upper limit gasket (4) of the special maintenance device of the present invention are assembled and inserted into the center hole of the upper end cover of the operating seat. When the lifting connecting rod (2) extends out of the position of the slide assembly, the lower limit gasket (5) and the lower limit nut (6) are used to tighten the bottom end of the slide assembly to achieve the limitation of the disc spring assembly and the slide assembly.

4. A special maintenance device for a steam turbine valve directly connected to a control seat as claimed in claim 1, characterized in that: The limit distance for disassembly of the upper end cover can be adjusted by externally rotating the upper limit nut (3) and the upper limit gasket (4).

5. A special maintenance device for a steam turbine valve directly connected to a control seat as claimed in claim 1, characterized in that: Remove the lower limit washer (5) and the lower limit nut (6) on the seating platform (7) and inspect the disc spring and slide assembly.

Images