Sliding connection device based on steam turbine LVDT and its use method

Abstract

The invention discloses a sliding connection device based on a steam turbine LVDT and a method for using the same. The sliding connection device comprises an upper end cover, a lower end body and a sliding connection piece. The top end of the upper end cover is connected to the tail end of a valve position feedback bracket, the head end of the valve position feedback bracket is horizontally connected to a valve stem of a steam turbine valve, the lower end body is located below the upper end cover and connected to the upper end cover by a locking bolt, and a circular hole is provided in the middle of the lower end body; the upper part of the sliding connection piece is located above the lower end body, the lower part passes through the lower end body through a circular hole, and the diameter of the circular hole is larger than the outer diameter of the lower part of the sliding connection piece, the lower part of the sliding connection piece is slidably connected to the lower end body through the circular hole, and the lower part of the sliding connection piece matches the inner thread of the LVDT iron core and is connected to the LVDT iron core thread. When installing the LVDT, loosen the locking bolts connecting the upper end cover and the lower end body to leave a gap between the upper end cover and the lower end body; after the LVDT is installed, gradually tighten the locking bolts and locking nuts connecting the upper end cover and the lower end body in a diagonal manner.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical equipment repair, and relates to a steam turbine, in particular to a sliding connection device based on a steam turbine LVDT and a use method thereof. Background Art

[0002] The steam turbine is equipped with a measuring device for detecting the valve position of each adjustable steam inlet valve - the turbine adjustable steam valve position feedback device (LVDT). Due to deviations in installation and construction, the center points of the LVDT's iron core and coil are not in a straight line, resulting in friction damage between the iron core and coil. When the LVDT is damaged, the measurement signal will fluctuate or jump significantly, causing the corresponding steam inlet valve to open or close uncontrollably, causing a significant fluctuation in the load of the generator set and endangering the safe and stable operation of the steam turbine generator set.

[0003] In view of the above-mentioned LVDT wear, when adjusting the LVDT, since the installation position of the LVDT coil is fixed and cannot be adjusted, the center point can only be adjusted by adding or removing gaskets at the bottom of the valve position feedback bracket. This adjustment method has a very small adjustable range and often cannot meet the requirements. In order to reduce LVDT wear, thermal workers need to spend a lot of energy to adjust the center of the LVDT core and coil, but LVDT wear and damage still occur from time to time, and the adjustment effect is not satisfactory. Summary of the invention

[0004] The purpose of the present invention is to provide a sliding connection device based on a steam turbine LVDT and a method for using the same, so as to solve the technical problem that the LVDT is worn and damaged due to the fact that the core and the center point of the coil of the steam turbine valve position feedback device (LVDT) are not in a straight line, resulting in abnormal load fluctuation of the steam turbine generator set.

[0005] The technical solution adopted by the present invention is a sliding connection device based on a steam turbine LVDT, comprising: an upper end cover, a lower end body and a sliding connection piece, wherein the top end of the upper end cover is connected to the tail end of a valve position feedback bracket, the head end of the valve position feedback bracket is horizontally connected to the valve stem of a steam turbine valve, the lower end body is located below the upper end cover and is connected thereto by a locking bolt, and a circular hole is provided in the middle of the lower end body; the sliding connection piece comprises a sliding connection plate and a sliding connection rod, the middle part of the bottom end of the sliding connection plate is fixedly connected to the top end of the sliding connection rod, the sliding connection plate is located above the lower end body, the sliding connection rod penetrates the lower end body through the circular hole, and the diameter of the circular hole is larger than the outer diameter of the sliding connection rod, the sliding connection piece is slidably connected to the lower end body through the circular hole, and the lower part of the sliding connection rod matches the inner thread of the LVDT core and is threadedly connected to the LVDT core.

[0006] Preferably, the upper end cover is plate-shaped, and a groove is provided in the middle of the lower end body corresponding to the upper end cover, and the upper end cover is embedded in the lower end body when connected.

[0007] Preferably, an upper end cover protrusion is provided in the middle portion below the upper end cover, the top end surface of the sliding connection plate is lower than the top end surface of the groove, and the bottom end surface of the upper end cover protrusion contacts the top end surface of the sliding connection plate.

[0008] Preferably, the upper end cover is connected to the valve position feedback bracket through an upper end cover connecting piece, and the upper end cover connecting piece includes an upper end cover connecting head and an upper end cover connecting rod, the bottom end of the upper end cover connecting head is fixedly connected to the top end of the upper end cover, the outer diameter of the upper end cover connecting head is larger than the outer diameter of the upper end cover connecting rod, and the bottom end of the upper end cover connecting rod is fixed to the middle of the top end of the upper end cover connecting head; the upper end cover connecting rod is externally threaded, and the tail end of the valve position feedback bracket matches the upper end cover connecting rod to open a mounting hole, and after the upper end cover connecting rod passes through the mounting hole, a locking nut is used to fix the upper end cover connecting rod and the valve position feedback bracket.

[0009] Preferably, the connection between the sliding connecting rod and the LVDT core is fixed with a locking nut.

[0010] Preferably, the cross section of the sliding connecting rod is a regular hexagon.

[0011] Preferably, the head end of the valve position feedback bracket is rigidly connected to the valve stem of the steam turbine valve.

[0012] The invention discloses an installation method of a sliding connection device based on a steam turbine LVDT, comprising:

[0013] Step 1: Fix the valve position feedback bracket on the valve stem of the turbine inlet valve;

[0014] Step 2: Vertically pass the upper end cover connector through the mounting hole on the valve position feedback bracket and tighten it with a nut, and then install the lower end body under the upper end cover with a locking bolt and a locking nut;

[0015] Step 3: When installing the LVDT, loosen the locking bolts and locking nuts connecting the upper end cover and the lower end body, so that there is a gap between the upper end cover and the lower end body;

[0016] Step 4: After the LVDT is installed, gradually tighten the locking bolts and locking nuts connecting the upper end cover and the lower end body in a diagonal manner. During the tightening process, flat washers and spring washers should be used to prevent the locking nuts from loosening.

[0017] Furthermore, under the premise of satisfying the steam inlet valve control of the steam turbine unit, a gap can be reserved between the upper end cover protrusion and the sliding connection, and the reserved gap is 0-1mm.

[0018] Furthermore, after the valve position feedback bracket is removed, the valve can be directly connected and positioned with other vertical devices through the upper end cover connector.

[0019] The beneficial effects of the present invention are as follows: compared with the prior art, the inspection and maintenance workload of thermal workers can be greatly reduced, and the wear of LVDT can be minimized. After the renovation construction, the problem that the center points of the LVDT core and the coil are not in a straight line caused by the construction or installation process can be eliminated, and the wear of the LVDT caused by the friction between the LVDT core and the coil can be avoided. It avoids the large fluctuation or jump of the measurement signal after the LVDT is damaged, resulting in the uncontrolled opening or closing of the steam inlet regulating valve of the steam turbine, causing a large fluctuation in the load of the generator set, and also avoids the occurrence of events that endanger the safe and stable operation of the steam turbine generator set due to the large fluctuation of the load of the steam turbine set.

[0020] By eliminating the valve position feedback bracket and directly connecting and positioning with other vertical equipment through the upper end cover connector, the application scope of the present invention can be expanded. The present invention can be used to directly connect and adjust the upper / lower suspension equipment of the equipment in the vertical direction, avoiding equipment damage or hidden dangers caused by lateral force on the suspension equipment due to installation and construction size deviation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a side view of the present invention;

[0022] Figure 2 A schematic diagram of the connection between the present invention and a device in a vertical direction;

[0023] Markings in the figure: 1. Upper end cover, 11. Upper end cover protrusion, 2. Upper end cover connecting piece, 21. Upper end cover connecting head, 22. Upper end cover connecting rod, 3. Lower end body, 4. Sliding connecting piece, 41. Sliding connecting plate, 42. Sliding connecting rod, 5. Valve position feedback bracket, 6. LVDT core, 7. Locking nut, 8. Other equipment in the vertical direction. DETAILED DESCRIPTION

[0024] The present invention will be further explained below in conjunction with the accompanying drawings to facilitate better understanding by those skilled in the art.

[0025] Example 1

[0026] like Figure 1-2 As shown, the sliding connection device based on the steam turbine LVDT includes: an upper end cover 1, an upper end cover connecting member 2, a lower end body 3, a sliding connection member 4, a valve position feedback bracket 5 and a LVDT iron core 6.

[0027] The upper end cover 1 is plate-shaped, and the top end of the upper end cover 1 is connected to the tail end of the valve position feedback bracket 5. The head end of the valve position feedback bracket 5 is horizontally connected to the valve stem of the turbine valve. The lower end body 3 is located below the upper end cover 1 and is connected to it by a locking bolt. Specifically, a groove is provided in the middle part of the lower end body 3 corresponding to the upper end cover 1. When connected, the upper end cover 1 is embedded in the lower end body 3 to prevent slipping, which is conducive to keeping the center lines of the upper end cover 1 and the lower end body 3 coaxial. A circular hole is provided in the middle of the lower end body 3; the sliding connecting member 4 includes a sliding connecting plate 41 and a sliding connecting rod 42, the middle of the bottom end of the sliding connecting plate 41 is fixedly connected to the top end of the sliding connecting rod 42, the sliding connecting plate 41 is located above the lower end body 3, the sliding connecting rod 42 penetrates the lower end body 3 through the circular hole, and the diameter of the circular hole is larger than the outer diameter of the sliding connecting rod 42, the sliding connecting member 4 is slidably connected to the lower end body 3 through the circular hole, the sliding connecting member 4 can slide freely within the range of the circular hole, and the lower part of the sliding connecting rod 42 matches the LVDT core 6 with a threaded connection with the LVDT core 6.

[0028] The connection and adjustment of the LVDT and the valve position feedback bracket 5 are achieved through the above-mentioned sliding connection device, which can keep the LVDT core 6 and the center point of the coil on the same straight line, and solve the problem that the LVDT core 6 and the center point of the coil are not on the same line due to the construction or installation process, which leads to the LVDT wear caused by the friction between the LVDT core 6 and the coil. It avoids the uncontrolled opening or closing of the steam inlet regulating valve of the turbine causing a large fluctuation in the load of the generator set due to the large fluctuation in the load of the steam turbine unit, and also avoids the occurrence of events that endanger the safe and stable operation of the steam turbine generator set due to the large fluctuation in the load of the steam turbine unit.

[0029] An upper end cover protrusion 11 is provided in the middle of the lower part of the upper end cover 1, the top end surface of the sliding connection plate 41 is lower than the top end surface of the groove, the bottom end surface of the upper end cover protrusion 11 contacts the top end surface of the sliding connection plate 41, and the upper end cover protrusion 11 can adjust the gap with the sliding connection part 4 by means of locking nuts and locking bolts and adding or reducing thin gaskets until it is fully tightened.

[0030] The upper end cover 1 is connected to the valve position feedback bracket 5 through the upper end cover connecting piece 2, and the upper end cover connecting piece 2 includes an upper end cover connecting head 21 and an upper end cover connecting rod 22. The bottom end of the upper end cover connecting head 21 is fixedly connected to the top end of the upper end cover 1, and the outer diameter of the upper end cover connecting head 21 is larger than the outer diameter of the upper end cover connecting rod 22. The bottom end of the upper end cover connecting rod 22 is fixed to the middle of the top end of the upper end cover connecting head 21; the upper end cover connecting rod 22 is externally threaded, and the tail end of the valve position feedback bracket 5 matches the upper end cover connecting rod 22 to open a mounting hole. After the upper end cover connecting rod 22 passes through the mounting hole, the upper end cover connecting rod 22 and the valve position feedback bracket 5 are fixed by a locking nut 7.

[0031] The connection between the sliding connecting rod 42 and the LVDT core 6 is fixed by a locking nut 7 to prevent loosening.

[0032] The cross section of the sliding connecting rod 42 is a regular hexagon, which is convenient for locking the sliding connecting piece 4 and the LVDT core 6 with a wrench.

[0033] The head end of the valve position feedback bracket 5 is rigidly connected to the valve stem of the steam turbine valve and moves along with the movement of the valve stem of the steam turbine valve.

[0034] Example 2

[0035] The invention discloses an installation method of a sliding connection device based on a steam turbine LVDT, comprising:

[0036] Step 1: Fix the valve position feedback bracket 5 on the valve stem of the steam turbine valve;

[0037] Step 2: vertically pass the upper end cover connector 2 through the mounting hole on the valve position feedback bracket 5 and fix it with the locking nut 7, and then install the lower end body 3 under the upper end cover 1 with the locking bolt and locking nut;

[0038] Step 3, threading the LVDT core 6 to the sliding connecting rod 42, and fixing the connection between the two with a locking nut 7; when installing the LVDT, loosen the locking bolts and locking nuts connecting the upper end cover 1 and the lower end body 3, so that there is a gap between the upper end cover 1 and the lower end body 3, so that the LVDT core 6 can automatically slide and align with the center point of the coil under the action of external force when it is inconsistent with the center of the coil;

[0039] Step 4: After the LVDT is installed, gradually tighten the locking bolts and locking nuts connecting the upper end cover 1 and the lower end body 3 in a diagonal manner. During the tightening process, flat washers and spring washers are required to prevent the locking nuts from loosening.

[0040] Furthermore, under the premise of satisfying the steam inlet valve control of the steam turbine unit, a gap can be reserved between the upper end cover protrusion 11 and the sliding connection 4, and the reserved gap is 0-1mm, which is convenient for the LVDT core 6 to automatically return to its original position during the operation of the unit, and avoids the wear of the LVDT core 6 and the coil caused by the deviation caused by thermal expansion and contraction of the equipment.

[0041] The use of a sliding connection device can solve the problem of frequent damage to the turbine unit's steam inlet valve LVDT due to wear and tear, and solve the abnormal opening and closing of the turbine unit's steam inlet valve due to abnormal LVDT feedback, thereby avoiding large fluctuations in the unit's load and improving the safety and stability of the unit's operation.

[0042] By eliminating the valve position feedback bracket 5, the application scope of the present invention can be expanded. The present invention can be used to directly connect and adjust the upper / lower suspension equipment 8 in the vertical direction, thereby avoiding equipment damage or hidden dangers caused by lateral force on the suspension equipment due to dimensional deviations in the installation construction.

[0043] The parts not described in detail in the present invention are all known technologies to those skilled in the art. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A sliding connection device based on a steam turbine LVDT, characterized in that: include: An upper end cover (1), a lower end body (3) and a sliding connection member (4), wherein the upper end cover (1) has a top end connected to the rear end of a valve position feedback bracket (5), the head end of the valve position feedback bracket (5) is horizontally connected to a valve stem of a steam turbine valve, the lower end body (3) is located below the upper end cover (1) and is connected to the upper end cover (1) via a locking bolt, and a circular hole is provided in the middle of the lower end body (3); the sliding connection member (4) comprises a sliding connection plate (41) and a sliding connection rod (42), the top end of the sliding connection rod (42) is fixedly connected to the middle of the bottom end of the sliding connection plate (41), the sliding connection plate (41) is located above the lower end body (3), and the sliding connection rod (42) passes through the lower end body (3) through the circular hole. ), and the diameter of the circular hole is larger than the outer diameter of the sliding connecting rod (42), the sliding connecting piece (4) is slidably connected to the lower end body (3) through the circular hole, and the lower part of the sliding connecting rod (42) matches the LVDT core (6) with a threaded connection with the LVDT core (6); the upper end cover (1) is in the shape of a plate, and a groove is provided in the middle of the lower end body (3) corresponding to the upper end cover (1). When connected, the upper end cover (1) is embedded in the lower end body (3), and an upper end cover protrusion (11) is provided in the middle of the lower part of the upper end cover (1), the top end surface of the sliding connecting plate (41) is lower than the top end surface of the groove, and the bottom end surface of the upper end cover protrusion (11) contacts the top end surface of the sliding connecting plate (41).

2. The sliding connection device based on steam turbine LVDT according to claim 1, characterized in that: The upper end cover (1) is connected to the valve position feedback bracket (5) via an upper end cover connecting piece (2), wherein the upper end cover connecting piece (2) comprises an upper end cover connecting head (21) and an upper end cover connecting rod (22), wherein the bottom end of the upper end cover connecting head (21) is fixedly connected to the top end of the upper end cover (1), the outer diameter of the upper end cover connecting head (21) is larger than the outer diameter of the upper end cover connecting rod (22), and the bottom end of the upper end cover connecting rod (22) is fixed to the middle of the top end of the upper end cover connecting head (21); the upper end cover connecting rod (22) is externally threaded, and a mounting hole is provided at the rear end of the valve position feedback bracket (5) to match the upper end cover connecting rod (22), and after the upper end cover connecting rod (22) passes through the mounting hole, a locking nut (7) is used to fix the upper end cover connecting rod (22) and the valve position feedback bracket (5).

3. The sliding connection device based on steam turbine LVDT according to claim 1, characterized in that: The connection between the sliding connecting rod (42) and the LVDT core (6) is fixed by a locking nut (7).

4. The sliding connection device based on steam turbine LVDT according to claim 1, characterized in that: The sliding connecting rod (42) has a regular hexagonal cross section.

5. The sliding connection device based on steam turbine LVDT according to claim 1, characterized in that: The head end of the valve position feedback bracket (5) is rigidly connected to the valve stem of the steam turbine valve.

6. The installation method of the sliding connection device based on the steam turbine LVDT according to any one of claims 1 to 5, characterized in that: include: Step 1: Fix the valve position feedback bracket (5) on the valve stem of the steam turbine valve; Step 2: vertically pass the upper end cover connector (2) through the mounting hole on the valve position feedback bracket (5) and secure it with a locking nut (7), and then install the lower end body (3) below the upper end cover (1) with a locking bolt and a locking nut; Step 3: When installing the LVDT, loosen the locking bolts and locking nuts connecting the upper end cover (1) and the lower end body (3) to leave a gap between the upper end cover (1) and the lower end body (3); Step 4: After the LVDT is installed, gradually tighten the locking bolts and locking nuts connecting the upper end cover and the lower end body in a diagonal manner. During the tightening process, flat washers and spring washers must be used to prevent the locking nuts from loosening.

7. The installation method of the sliding connection device based on the steam turbine LVDT according to claim 6, characterized in that: On the premise of satisfying the steam inlet valve control of the steam turbine unit, a gap is reserved between the upper end cover protrusion (11) and the sliding connection member (4), and the reserved gap is 0-1 mm.

8. The installation method of the sliding connection device based on the steam turbine LVDT according to claim 6, characterized in that: After the valve position feedback bracket (5) is removed, the valve is directly connected and positioned with other vertical devices (8) through the upper end cover connector (2).

Images