JPH0768883B2 - Method and apparatus for sliding back seat surface of main valve of turbine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (3-1) Field of Industrial Application The present invention enables automation of the sliding work of the backseat surface of the main valve of a large-scale turbine for power generation, etc., which reduces labor and improves work efficiency. The present invention relates to a sliding method and a sliding device used for the sliding method.

(3-2) Conventional technology A main valve of a large turbine used for power generation, for example, a reheat steam stop valve (RSV) is shown in Fig. 7 (a diagram including a partial cross section showing a main part and hatching is omitted). The guide piece 1 of the part indicated by the circle X among them is as shown in FIG.
The valve seat 2 attached to the valve seat 3 and the back seat surface 4 of the valve rod 3 must be brought into contact with each other at the time of periodic repair and other necessary conditions. This sliding is conventionally performed by the method shown in FIG. That is, in the figure, the valve RSV
The guide piece 1 is supported by a receiving plate 6 fixed to the structure 5. A valve block 3 is suspended from a chain block 7 attached to a structure via a spring hanger 8 and a valve rod suspension fitting 9 and inserted into the guide piece 1. A handle 10 for sliding is attached to the valve rod suspension fitting 9.

The work is performed by the following procedure.

The worker 11 operates the chain block 7 to lift the valve rod 3 and apply the abrasive to the back sheet surface 4.

The chain block 7 is operated to suspend the valve rod 3 and adjust the distance between the back seat surface 4 and the valve seat 2 mounted in the guide piece 1 to be about 10 to 20 mm.

Grasp the handle 10 and push the valve rod 3 downward against the force of the spring, hit the back seat surface 4 against the valve seat surface 2,
It also gives the stem a rotational movement. This tapping work and rotation work are repeated several tens to 100 times.

Repeat steps (1) to (4) until a good contact is made between the back seat surface 4 and the valve seat surface 2. The quality of the hit is judged by the state of the backsheet surface.

The above-described back sheet surface lapping work is a very monotonous work and a very laborious work. The work time for hitting one valve rod is about one day for hitting relatively easily, and 2-3 days for hitting difficult. Vertical movement of the valve rod for hitting is per day
5,000 to 6,000 times. That is, this work is a repetitive monotonous work and requires a great deal of labor, so that it is a work with great fatigue.

(3-3) Problems to be Solved by the Invention The present invention solves the above-mentioned drawbacks of the method for sliding the backsheet surface of the main valve of the turbine, greatly reduces labor, and shortens work time. SUMMARY OF THE INVENTION An object of the present invention is to provide a sliding method for a back seat surface of a main valve of a turbine and a sliding device used for the same, which can improve work efficiency.

(3-4) Means for Solving the Problems The present invention analyzes the repetitive work of the conventional sliding method of the back seat surface of the main valve of the turbine, and as a result, it is found that it is reciprocating in the vertical direction and in the horizontal direction. It is found that the above-mentioned problems are solved by the combination of the rotational movement of (1) and the reciprocating rotational movement, and adopting the following method that automates these repetitive operations.

That is, it supports a guide piece of a main valve of a turbine by a receiving plate fixed to a structure, and inserts a valve rod suspended in the structure through a spring hanger into the guide piece,
Sliding of the backseat surface of the main valve of the turbine, which is performed by applying a polishing abrasive to the backseat surface of the valve rod and then striking the backseat surface against the surface of the valve seat mounted in the guide piece. In the method, an air cylinder that is connected to an air source through a solenoid valve and that reciprocates in the vertical direction, and an air cylinder that reciprocates in the horizontal direction are attached to a transmission mechanism that contacts the end of the valve rod. The operation mechanism consisting of a timing pulse circuit and a solid-state relay adjusts the opening and closing of the solenoid valve to give a vertical reciprocating motion and a horizontal reciprocating rotary motion or rotary motion to perform the sliding work. This is a method for sliding backsheet surfaces of main valves of turbines characterized by being automated.

The present invention solves the above-mentioned problems more concretely by presenting an apparatus used in the above-mentioned rubbing method.

(3-5) Example An example of the present invention will be described below with reference to the drawings. FIG. 1 exemplifies a method of sliding backsheet surfaces for main valves of a turbine according to the present invention. In the figure, for example, a guide piece 1 of a reheat steam stop valve (RSV) is supported by a receiving plate 6 fixed to a structure 5. A valve block 3 is suspended from a chain block 7 attached to a structure via a spring hanger 8 and a valve rod suspension fitting 9 and inserted into the guide piece 1.

A sliding device 21 for a back seat surface of a turbine main valve according to the present invention is set on a floor surface 12 below a valve rod.
The gap between the upper surface of the transmission mechanism 41 of the sliding device and the lower end surface of the valve rod is adjusted to about 5 to 10 mm. The sliding device 21 is composed of this transmission mechanism 41, an air cylinder that reciprocates vertically in the mechanism, and an air cylinder that gives horizontal reciprocation, and an operation mechanism that adjusts these movements (for detailed configuration and operation, see (Detailed later).

The work is performed by the following procedure.

The worker 11 operates the chain block 7 to lift the valve rod 3 and apply the abrasive to the back sheet surface 4.

Adjust the air pressure of the equipment so that the valve stem can be lifted upward against the load between the back seat surface and the valve seat shown in the next section.

The chain block 7 is operated to suspend the valve rod 3, and after the back seat surface 4 comes into contact with the valve seat 2, the chain block is further lowered, and the spring load applied to the spring hanger 8 is adjusted to adjust the back seat surface and the valve. Make sure that a certain load is applied to the seat. In the case of the example, the weight of the valve stem is
Although it is 150 kg, use a spring hanger of 180 kg. In addition, the spring load when lowering the chain block
It is desirable to adjust it to about 130 kg (the load between the back seat surface and the valve seat is about 20 kg).

Turn on the start switch of the operation box 13, operate the air cylinder for reciprocating vertical movement to bring the upper surface of the transmission mechanism of the sliding device into contact with the lower end surface of the valve rod, further lift the valve rod, and then drop the valve rod. , Hit the back seat surface to the seat surface. Rotate or reciprocate the stem as required. This is repeated until the number of hits reaches a predetermined value (100 to 150 in this example).

The procedure of and is repeated until a good contact is made between the back seat surface 4 and the valve seat surface 2. The quality of the hit is judged by the state of the backsheet surface.

It is desirable that the striking interval be about once every 1.5 seconds, and it is convenient if the number of striking is displayed digitally in the operation box.

FIG. 2 is a view including a partial cross section illustrating a sliding device for a backseat surface of a main valve of a turbine according to the present invention. In the figure, a sliding device 21 is installed on the floor surface 12, and the gap between the upper surface of the transmission mechanism 41 and the lower end surface of the valve rod 3 is 5 to 10 mm as described above. Is being adjusted.

Compressed air sent by a pipe 22 connected to an air source is sent to a solenoid valve 24 for vertical movement and a solenoid valve 25 for rotary movement via a source pressure valve 23, and further, an air cylinder 26 for vertical movement and air for rotary movement. It is sent to cylinder 27. The tip of the air cylinder 26 is directly connected to the transmission mechanism 41, but the tip of the air cylinder 27 is connected to the transmission mechanism 41 via the uniball joint 28, and the movement direction of the cylinder and the movement direction of the transmission mechanism are Even if there is a slight deviation, the motion is transmitted smoothly.

The movements of air cylinders 26 and 27 are controlled by solenoid valves 24 and 25, respectively.
The opening and closing of each solenoid valve is controlled by the operating mechanism 31
Controlled by. The operation mechanism 31 is housed in the operation box 13, and is composed of a pulse generation circuit, a timing pulse generation circuit 32 including each timing generation circuit, a solid state relay 33, a switch and the like.
From this operating mechanism, vertical motion pulse, reciprocating rotary motion pulse, rotary motion pulse as shown in FIG.
This pulse causes each solenoid valve to open and close, thereby operating each air cylinder.

The transmission mechanism 41 includes a lower metal fitting 42, a middle metal fitting 43, an upper metal fitting 44, a soft rubber 45 and the like. FIG. 4 ((a) is a plan view,
(B) is a front view) showing the lower metal fitting 42, FIG. 5 ((A) is a front view, (B) is a bottom view) is a drawing showing the middle metal fitting 43, and FIG. 6 ((A)) Is a front view, (b) is a bottom view) and FIG. 4 to 6 and 3, the lower metal fitting 42 of the transmission mechanism has a cylindrical shape with a flange, and a hole 42a provided in the flange portion.
A tip portion of the air cylinder 26 is inserted through and fixed by a bolt 46.

The middle metal fitting 43 has a cylindrical shape with a bottom, and the thrust bearing 47 and the lower metal fitting 42 are housed inside thereof. The lower metal fitting and the middle metal fitting are rotatable relative to each other by the action of the thrust bearing. A screw hole for attaching the uniball joint 28 on the outer surface of the middle metal fitting
43a is provided. A screw hole 43b is provided on the end surface.

The upper metal fitting 44 has a stepped cylindrical shape, the end surface of the small diameter portion of the upper metal fitting 44 is brought into contact with the end surface of the middle metal fitting 43, the bolt 48 is inserted into the inner surface of the upper metal fitting, and screwed into the screw hole 43 to form the upper metal fitting. It is fixed to the middle part. A soft rubber 45 is attached to the end surface of the large diameter portion of the upper fitting.

Next, what movement is transmitted to the valve stem 3 by the transmission mechanism 41 when the operation mechanism 30 emits a pulse as shown in FIG. 3 will be described. First, when the vertical movement pulse and the reciprocating rotary movement pulse are combined, the vertical movement solenoid valve 24 is ON at point A, air is sent to the vertical movement air cylinder, and the air cylinder rises. However, the valve stem is also rising accordingly.
The load of the valve rod acts on the soft rubber 45 of the transmission mechanism.
At point B, the solenoid valve 25 for rotary motion is turned ON from the OFF state.
Then, the upper metal fitting 44 of the transmission mechanism rotates counterclockwise by the action of the air cylinder 27 for rotational movement. Valve rod 3
Rotates left due to the frictional action between its lower end and the soft rubber.

At point C, the solenoid valve 24 is turned off, the valve stem falls,
As a result, the back seat surface 4 of the valve rod is struck against the valve seat 2. At the point D, the valve rod 3 is rising again, and in that situation, the solenoid valve 25 is turned off, so that the valve rod rotates clockwise. By repeating this movement, the valve rod 3 repeats the striking operation while reciprocatingly rotating.

When the vertical motion pulse and the rotary motion pulse are combined, the motions at points A and B are the same as in the case of the combination of the vertical motion pulse and the reciprocating rotary motion pulse, and the valve rod rotates counterclockwise. , The valve rod falls at point C. At the point C, the right rotation motion of the upper fitting 44 of the transmission mechanism is started at the same time. However, at this time, since the frictional action between the lower end of the valve stem and the soft rubber has already been lost, the valve stem does not rotate. At point D, the valve stem rotates counterclockwise as at point B. Therefore, in this case, the valve rod repeats the striking operation while rotating in one direction (left rotation in this example).

The above-described embodiments mainly apply the present invention to the reheat steam stop valve (RS
V) is described, but other turbine main valves such as MSV (main blocking valve), ICV (intermediate blocking valve, the structure of the main part are as shown in the circle Y in FIG. 7). However, the present invention can be effectively carried out even if it has a sliding portion as shown by P and Q). Further, it is clear that the present invention can be effectively applied to the sliding of a large valve having a sliding surface which is generally a part of a conical surface.

(3-6) Effects of the Invention The present invention uses a solenoid valve and an air cylinder to generate vertical movement and rotary movement, which are transmitted to a valve stem by a transmission mechanism, and each movement is controlled by an operating mechanism. By automating the sliding operation of the back seat surface of the main valve of the turbine, the following excellent effects are exhibited.

Since the work performed by the worker is only the work of applying the abrasive to the back sheet surface, the labor can be significantly reduced.

It is possible to reduce the work time for laminating by 20 to 30% as the work efficiency increases.

The number of times of beating can be digitally displayed to control the timing of applying the abrasive material, and since the beating pressure is always uniform, it is possible to carry out a sliding work of excellent quality.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a method of sliding a main valve backseat surface of a turbine according to the present invention, and FIG. 2 is a diagram showing an example of a main valve backseat surface sliding device of a turbine according to the present invention. FIG. 3 shows vertical movement pulses, reciprocating rotary movement pulses, and rotary movement pulses emitted by the operating mechanism. FIG. 4 ((a) is a plan view, (b) is a front view) shows a lower metal fitting. Fig. 5, Fig. 5 ((a) is a front view, (b) is a bottom view) shows a middle metal fitting, and Fig. 6 ((a) is a front view, (b) is a bottom view) is an upper metal fitting. The drawings shown in FIGS. 7 and 7 are views showing the structure of the main part of the reheat steam stop valve (RSV) (a drawing including a partial cross section, hatching is omitted), and FIG. 8 is a conventional one. It is the figure which showed the sliding method. 1 ... Guide piece, 2 ... Valve seat 3 ... Valve rod, 4 ... Back seat surface 5 ... Structure, 6 ... Support plate 7 ... Chain block 8 ... Spring hanger 9 ... Valve rod suspension Metal fitting 10 …… Handle, 11 …… Worker 12 …… Floor, 13 …… Operation box 21 …… Sliding device 22 …… Piping, 23 …… Reducing valve 24 …… Solenoid valve for vertical movement 25 …… Rotating Solenoid valve for movement 26 …… Air cylinder for vertical movement 27 …… Air cylinder for rotary movement 28 …… Uniball joint 31 …… Operating mechanism 32 …… Timing pulse generation circuit 33 …… Solid state relay 41 …… Transmission mechanism, 42 …… Lower metal fitting 42a …… Hole, 43 …… Middle metal fitting 43a …… Screw hole, 43b …… Screw hole 44 …… Upper metal fitting, 45 …… Soft rubber 46 …… Bolt 47 …… Thrust bearing 48 …… Bolt X, Y ... Yen, P, Q ... Sliding part

Claims (4)

[Claims] 1. A guide piece for a main valve of a turbine is supported by a receiving plate fixed to a structure, and a valve rod suspended through a spring hanger is inserted into the structure into the guide piece. Sliding of the backseat surface of the main valve of the turbine, which is performed by applying a polishing abrasive to the backseat surface of the valve rod and then striking the backseat surface against the surface of the valve seat mounted in the guide piece. In the method, an air cylinder that is connected to an air source through a solenoid valve and that reciprocates in the vertical direction, and an air cylinder that reciprocates in the horizontal direction are attached to a transmission mechanism that contacts the end of the valve rod. An operating mechanism consisting of a timing pulse generation circuit and a solid-state relay is used to adjust the opening and closing of the solenoid valve to give a vertical reciprocating motion and a horizontal reciprocating rotary motion or rotary motion. Sliding fit method for the main valve backsheet surface of the turbine, characterized in that automates the sliding fit work. 2. One end is attached to a transmission mechanism that is in contact with the end of the valve rod of the main valve of the turbine suspended vertically in the guide piece and rotatably suspended in the horizontal plane, and the other end is fixed. An air cylinder that reciprocates in the vertical direction by an air source connected via a solenoid valve, one end of which is attached to the outer periphery of the transmission mechanism and the other end of which is fixed, and which is connected via the solenoid valve. Main valve of the turbine, which is composed of an air cylinder that reciprocates in the horizontal direction by an air source, a timing pulse generation circuit, and a solid state relay, and an operation mechanism that outputs an opening / closing signal to the two solenoid valves. Device for back sheet surface 3. The transmission mechanism has a cylindrical shape with a flange, one surface of which is provided with an air cylinder reciprocating in the vertical direction, and the other surface of which is a lower metal fitting to which a thrust bearing is attached. , Cylindrical shape with bottom,
The lower metal fitting and the thrust bearing are housed inside, and the outer peripheral surface of the cylinder has a middle metal fitting to which an air cylinder reciprocating in the horizontal direction in the cutting line direction is attached via a ball joint, and a stepped metal fitting. It has a cylindrical shape, and the middle metal fitting is attached to the end face of the small diameter part,
The main valve for a turbine according to claim 1, characterized in that the end surface of the large-diameter portion is composed of an upper metal fitting which is in contact with the end surface of the valve rod via soft rubber. Back sheet surface sliding method. 4. A lower metal fitting having a cylindrical shape with a flange, said one surface having an air cylinder reciprocating in the vertical direction attached to one surface thereof, and a thrust bearing attached to the other surface thereof. , Cylindrical shape with bottom,
The lower metal fitting and the thrust bearing are housed inside, and the outer peripheral surface of the cylinder has a middle metal fitting to which an air cylinder reciprocating in the horizontal direction in the cutting line direction is attached via a ball joint, and a stepped metal fitting. It has a cylindrical shape, and the middle metal fitting is attached to the end face of the small diameter part,
3. The main valve for a turbine according to claim 2, wherein the end surface of the large diameter portion is composed of an upper metal fitting which is in contact with the end surface of the valve rod via soft rubber. Back sheet surface sliding device.