JPH10176502A - Integral steam valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of valve sand the weight, and shorten the assembling time by integrally assembling two vertical main steam stop valves and three steam control valves in a valve chamber, and arranging one integral steam valve for a high and intermediate pressure casings. SOLUTION: In an integral steam valve, vertical main steam stop valves 3, which abut on valve seals 61 arranged in both ends of a valve chamber 4 with a lowering of a valve rod 32 so as to cut the flow-in of the main steam into the valve chamber, and a first steam control valve 1 arranged at a central part of the valve chamber, of which inner part is enlarged, and two second steam control valves 2 having a valve throat diameter smaller than that of the first steam control valve 1 are integrally provided in the valve chamber. One set of this integral steam valve is provided for a steam turbine high and intermediate pressure casings.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated steam valve which is applied to a large-sized commercial steam turbine such as a power plant and is provided in a valve chamber through which main steam flows into a steam turbine nozzle.

[0002]

2. Description of the Related Art A main steam stop valve for supplying a steam flow according to a load of a steam turbine for driving a generator or the like at a power plant to a nozzle, and a steam control valve are provided adjacent to the nozzle. 2. Description of the Related Art An integrated steam valve that is integrally incorporated in a valve chamber that is made to flow is conventionally used. FIG.
It is a partial plan view of a relatively large-sized steam turbine for business use or the like provided with an integrated steam valve used conventionally.

As shown in the figure, one main steam stop valve 0
An integrated steam valve in which two or more steam control valves 03 are integrally incorporated into a valve chamber 04, the axial direction of the valve chamber 04 is substantially parallel to the axial direction of the high-intermediate-pressure car room 01, It is arranged on each side of the room 01. In the figure, 05 is a front bearing stand, 06 is an outer garment, 07 is an intercept valve, and 08 is a reheat steam stop valve.

[0004] This integral type steam valve has an A-
As shown in FIG. 3 which is a side view in FIG. 3A, on both sides of the high- and intermediate-pressure car room 01, the valve rooms 04 and 04 are installed via mounts respectively fixed on the floor at the upper end of the outer garment 06. The main steam stop valve 0 that opens and closes the steam passage of the main steam S flowing from the main steam inlet 09 into the steam chamber in the valve chamber 04
2. The main steam S flowing into the steam chamber of the valve chamber 04 is
As described above, the steam control valve 03 for adjusting the flow rate of the main steam discharged to the nozzle provided adjacent to the nozzle 4 is integrally incorporated in the valve chamber 04.

The main steam stop valve 02 is provided with a valve chamber 04
As shown in FIG. 4, which is a partial cross-sectional view of FIG. 4, the valve chamber 04 which rises from below and allows the main steam S flowing from the main steam inlet 09 to flow into a steam reservoir inside the horizontally installed valve chamber 04.
A valve stem 022 which is inserted into a bent portion of a steam passage provided on the inner surface of the bush 023 and which extends and retreats along the axial center of the bush 023, and a main valve 0 attached to the tip of the valve stem 022.
21, the outer peripheral front surface of the main valve 021 which advances and retreats in the horizontal direction comes into contact with or separates from the tapered surface of the inlet portion of the valve seat 041 inserted into the inner surface of the vapor reservoir inlet of the valve chamber 04, A horizontal type that can control the flow of the main steam S flowing from the main steam inlet 09 into the steam pool is adopted.

As shown in FIG. 3, two steam control valves 03 are provided in the axial direction of the steam reservoir in the valve chamber 04, and the valve shaft is moved up and down by an actuator 010 provided at the upper end. A vertical type is used in which a valve element provided at a lower end is brought into contact with or separated from a valve seat to control a flow rate of main steam flowing into a steam reservoir of a valve chamber 04 to a nozzle.

As described above, the conventional integral type steam valve has a horizontal plug valve so that the main steam stop valve 02 and the steam control valve 03 are conveniently integrated in the valve chamber 04. In general, the steam control valve 03 employs a vertical plug valve, and the integrated steam valve integrated in this manner is, as described above, provided on both sides of the high- and medium-pressure car room 01 (as described above). One set each (left and right) is arranged substantially parallel to the high- and medium-pressure car room 01. In addition, since the integrated steam valve is basically symmetrically designed and arranged with respect to the high and medium pressure compartment 01,
FIG. 3 shows a case in which two steam control valves 03 are provided. However, the steam control valve 03 is provided with two to four valves for each set of integrated steam valves according to the steam turbine output. It is usual that a total of 4 to 8 steam control valves 03 are provided for one high-medium pressure compartment 01 in total.

Further, two steam control valves 03 shown in FIG. 3 are provided for one set of integral steam valves, and a total of four steam control valves 03 are provided for the high- and medium-pressure compartment 01. In such a case, the steam control valve 03 is often operated by opening two steam control valves 03 at the same time. In this case, only three valves can be used. That is, when three steam control valves 03 are provided in one set of integral steam valves, the steam control valve 03 uses the two steam control valves 03 at the same time to open the main steam S at about 70% load by the nozzle. Usually, it is designed so that it can be supplied to the steam generator. During the normal operation, as shown in FIG.
By opening the steam control valves 03 simultaneously and opening one steam control valve 03 of the other set, the main steam S required for 100% load
Is supplied to the nozzle.

However, the above-mentioned conventional integrated steam valve has the following disadvantages. (1) There is a problem that the main steam stop valve 02 adopts a horizontal type in view of the formation of the integral steam valve. That is, in the conventional integrated steam valve, as shown in FIG. 4, the main steam stop valve 02 uses a horizontal plug valve which is made horizontal, so that the valve stem 0 generated by the weight of the main valve 021 is used.
22, the main valve 0 provided at the tip of the valve stem 022
In some cases, the contact adjustment between the valve 21 and the valve seat 041 may be insufficient, and the cutoff of the main steam S may be insufficient. For this reason, upon assembly, it is necessary to adjust the contact between the main valve 021 and the valve seal 041 in consideration of the deflection of the valve stem 022. There is a problem that takes time.

(2) Further, since the main steam stop valve 02 is of a horizontal type and the valve rod 022 is horizontally arranged, an integral steam valve as shown in FIG. There is a problem in terms of maintainability due to the arrangement on the floor. That is, since the integrated steam valve is disposed on the floor on both sides close to the high / intermediate pressure compartment 01, the space around the high / intermediate pressure compartment 01 is narrowed, and the maintainability of the high / intermediate pressure compartment 01 is deteriorated. There is a problem of doing.
Further, in order to solve this problem, it is necessary to secure a sufficient space around the high- and medium-pressure vehicle room 01 and to install an integrated steam valve, so that the outer jacket 06 of the steam turbine becomes large and the cost increases. Occurs.

(3) Further, during the normal operation, the main steam stop valve 02 and the steam control valve 03 need to be subjected to a valve test in order to confirm a reliable opening and closing operation of the valve.
There are also problems with this valve test. That is, as described above, the steam control valve 03 is, as shown in FIG. 5 (a), two steam control valves provided in a set of integral steam valves provided on one side of the high- and medium-pressure compartment. 03 at the same time and the opening of one steam control valve 03 provided on another set of integrated steam valves provided on the other side of the high- and medium-pressure car room 01, the main steam required at 100% load is reduced. It is supplied to the nozzle.

Therefore, in the valve test, when a valve test is performed when a load of 100% is taken with these three valves, as shown in FIG. When the main steam stop valve 02 is fully closed for testing,
Since only the flow rate due to the simultaneous opening of the other two steam control valves 03 flows through the nozzle, the flow rate of the main steam passing through the nozzle is reduced, and the load may be about 70%. For this reason, every time a valve test of the main steam stop valve 02 is performed, it is necessary to perform an operation of reducing the load in advance, and there is a problem that the operation at the time of the valve test becomes complicated.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the conventional integrated steam valve, the present invention has two main steam stop valves having a vertical shape and one first steam stop valve having a large flow rate. A steam control valve and three steam control valves, each of which is provided with two second steam control valves provided on both sides of the first steam control valve, are integrally incorporated in a valve chamber, and one for a high-intermediate-pressure car room. It is an object to provide an integrated steam valve provided.

[0014]

Therefore, the integrated steam valve of the present invention has the following means. The main steam stop valve and the steam control valve, which are integrated with the valve chamber or the valve chamber and the valve chamber, are incorporated separately into the main steam inlets fixed to both ends of the valve chamber, and constitute an integrated steam valve. And a single integrated steam valve is provided for the high and medium pressure cabin of one steam turbine.

(1) Valve seats provided at both ends of a valve chamber arranged in a horizontal state and provided at a main steam inlet portion for introducing main steam into the valve chamber are respectively raised and lowered by a valve stem.
Two main plug stop type main steam stop valves that control the flow of main steam into the valve chamber by contacting and releasing the main valve provided on the valve stem. In addition, the main steam inlet provided with the main steam stop valve may be provided integrally with the valve at both ends of the valve,
Further, a member formed separately from the valve body may be fixed to both ends of the valve body.

(2) Between the valve seats at the main steam inlet provided at both ends of the valve chamber, they are arranged in series in the axial direction of the valve chamber, and flowed into the valve chamber by opening the main steam stop valve. The following first steam control valve and second steam control valve adopting a vertical plug valve similar to the conventional steam control valve for controlling the supply of the main steam to the nozzle.
Three steam control valves consisting of steam control valves. (A) One first steam control valve which has a large valve throat diameter and is disposed substantially at the center of a valve chamber whose inside is expanded from both sides. (B) On both sides of the first steam control valve, the valve throat diameters are smaller than the valve throat diameter of the first steam control valve. Two second steam control valves. In addition, the valve throat diameter of the first steam control valve is equal to √2 of the valve throat diameter of the second steam control valve.
Preferably, it is about twice.

As described above, the steam control valve constituting the integral steam valve of the present invention is different from the conventional integral steam valve in which two sets of a total of 4 to 8 even-numbered valves are used. A three-valve design consisting of one first steam control valve and two second steam control valves changed to a set of three valves, and the first steam control valve The valve and the second steam control valve are arranged side by side in the middle, left and right in order, and the valve throat diameter of the first steam control valve located in the middle is
The diameter of the valve throat of the other two second steam control valves was set to be approximately √2 times. Along with this, a valve chamber having a larger diameter inside the valve chamber in the central area where the first steam control valve is installed is used.

As described above, the valve chamber is provided with the first throats having different throat diameters.
By sharing the steam control valve and the second steam control valve, 1
The configuration is such that only one valve chamber is provided in each of the high and medium pressure compartments. The main steam stop valve employs a vertical plug valve driven from below, and has a configuration in which the main valve comes into contact with valve seals provided at both ends of one valve chamber.

In the integrated steam valve of the present invention, the main steam stop valve is of a vertical type using a vertical plug valve type as described above, so that the valve stem of the main steam stop valve does not bend. Alignment between the main valve provided at the tip of the valve and the valve seat provided at the steam inlet is always good. For this reason, at the time of assembly, it is necessary to adjust the contact between the main valve and the valve seat in consideration of the deflection of the valve stem. The contact adjustment can be easily performed without an assembling expert. At the same time, the time required for assembly can be reduced.

Further, in the steam control valve, the conventional four-
A three-valve design in which eight even-numbered valves are changed to three valves, one valve chamber is shared by three valves, and the main steam stop valve is driven up from the bottom to drive By providing the plug valve on both sides of one valve chamber, the size of the integrated steam valve can be reduced, the arrangement of the integrated steam valve is less restricted, and the maintenance of the high- and medium-pressure car room is reduced. In consideration of this, it is possible to arrange an integrated steam valve. As a result, the maintainability of the high-to-medium-pressure compartment is improved without increasing the size of the steam turbine outer garment, which is accompanied by an increase in cost.

Even when one of the main steam stop valves is closed at the time of the valve test, the main steam from the other main steam stop valve to the other steam control valve provided at the other end of the valve chamber is provided. And the restriction of the main steam flow rate is eliminated, so that a valve test can be performed at 100% load.
Thereby, the operation of reducing the load on the steam turbine at the time of the valve test becomes unnecessary, and the valve test can be easily performed.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an integrated steam valve according to the present invention will be described below with reference to the drawings. FIG. 1 is a partial sectional view showing a first embodiment of the integrated steam valve of the present invention.

In the drawing, 1 is a first steam control valve, 2 is a second steam control valve, 3 is a main steam stop valve, 4 is a valve chamber, 5 is an actuator, and 6 is a main steam inlet. Among the steam control valves, the valve throat diameter of the first steam control valve 1 was set to √2 times the valve throat diameter of the second steam control valve 2. Valve room 4
Uses a valve in which the inner diameter 41 of the valve chamber at the center where the first steam control valve 1 is provided is larger than that of the other portions. And
The steam control valve provided in the valve chamber 4 includes a first steam control valve 1 and two second steam control valves 2 provided on both sides of the first steam control valve.
And a high-medium pressure compartment 0 shown in FIG.
One valve chamber 4 is provided for one.

In the main steam stop valve 3 provided at the main steam inlets 6 provided at both ends of the valve chamber 4, the valve rod 32 from the actuator 5 provided at the lower part is moved up and down. The valve 31 is brought into contact with or separated from a valve seal 61 provided in the main steam inlet 6 to form a vertical plug valve of a type that opens and closes a steam passage 62 provided in the main steam inlet 6. As described above, the steam control valve including the first steam control valve 1 and the second steam control valve is provided in the valve chamber 4 in a three-valve design, and is provided at the main steam inlet 6 connected to both ends of the valve chamber 4. By providing the main steam stop valve including two vertical plug valves, the integrated steam valve of the present embodiment can be made compact.

Then, the integrated main steam valve constructed as described above is disposed under the floor in front of the high / intermediate pressure compartment 01 shown in FIG.
By arranging one set of the intercept valve 07 and one set of the reheat steam stop valve 08 on both sides thereof, it is possible to secure a maintenance floor required for maintenance of the high- and intermediate-pressure vehicle room 01 and make the outer garment 06 compact. In addition, the intercept valve 07 and the reheat steam stop valve 08 may be arranged at the same positions as in the related art, and there is no need to change the design accompanying the rearrangement of these. In FIG. 1, the valve chamber 4 and the main steam inlet 6 are formed separately, and one end of the main steam inlet 6 is fixed to both ends of the valve chamber 4. The main steam inlet section 6 can be provided integrally with the section.

Next, the operation of the steam control valves 1 and 2 and the main steam stop valve 3 constituting the above-mentioned integrated steam valve will be described. For one of the main steam stop valves 3 provided at the main steam inlets 6 provided at both ends of the valve chamber 4, the main steam S with a 100% load of the steam turbine is introduced into the valve chamber 4. Since the steam turbine is operated, a 100% load operation in which only one of the two main steam stop valves 3 is fully opened is possible.

Therefore, in the valve test of the main steam stop valve 3 which is performed during the normal operation, first, a test for opening the two main steam stop valves 3 at the same time is performed. Are simultaneously opened, the three steam control valves of the first steam control valve 1 and the second steam control valve 2 provided in the valve chamber 4
The main steam S, which keeps the steam turbine at 100% load, is supplied to the nozzle, so that the steam turbine does not go over 100% load. Therefore, the valve test including the simultaneous opening of the main steam stop valve 3 is performed alternately in a state where the steam turbine is kept at 100% load by the opening degree of the first steam control valve 1 and the second steam control valve 2. be able to.

In the valve test of the steam control valve,
One side of the main steam stop valve 3 is fully closed, and one of the three steam control valves of the first steam control valve 1 and the second steam valve 2 is operated to perform a valve test. In this way, even when a valve test of the steam control valve is performed during the normal operation, the main steam S maintaining 100% load capacity is kept in the valve chamber 4 on only one side of the two main steam stop valves 3. Since the power is supplied, the load does not fluctuate.

That is, in the conventional integrated steam valve, two steam control valves are provided for one valve chamber 4 in order to make the integrated steam valve more compact.
In a valve test during operation, the load fluctuates when one side is actuated (closed). In addition, delicate load control cannot be performed when the load increases. Further, when four valves are provided for one valve chamber 4, the valve chamber 4 is enlarged and the arrangement space becomes a problem, and the cost is not reduced without changing the physical quantity as compared with the conventional case. There was a problem such as.

For this reason, the steam control valve provided in the valve chamber 4
Three valves are adopted, one of the three valves is a first steam control valve 1 in which the valve throat diameter is √2 times larger than the other valves, and one valve of the first steam control valve 1 corresponds to two valves. The throat area serves the role of As a result, the steam control valve performs the function of four valves with three valves. Even during the valve test during operation, the load does not fluctuate, the load can be finely controlled, and the weight is reduced. Thus, the cost can be reduced.

Further, in the integral steam valve of the present embodiment, the main steam stop valve 3 is a vertical valve using a vertical plug valve type, so that the valve rod of the main steam stop valve 3 does not bend. The alignment between the main valve 31 provided at the tip of the valve stem 32 and the valve seat 61 provided at the steam inlet 6 is improved. For this,
The adjustment of the contact between the main valve 31 and the valve seat 61 in consideration of the deflection of the valve stem at the time of assembly becomes easy, and the assembly time can be shortened.

[0032]

As described above, according to the integrated steam valve of the present invention, according to the constitution set forth in the claims, (1) the main steam stop valve has a vertical plug driven from below. By providing valves at both ends of one valve chamber, even if one main steam stop valve is closed during the valve test, steam from the other main steam stop valve to all steam control valves is transmitted. The availability of the steam supply and the elimination of the restriction on the steam flow allow the valve test to be performed at 100% load during the normal operation of the steam turbine.

(2) In the steam control valve, the conventional 4 to 4
Eight even valves to one first steam regulator, two second
A three-valve design changed to three steam control valves, one valve chamber is shared by at least three valves, and the main steam stop valve and the steam control valve are integrated with the high- and medium-pressure compartment. Since the integrated steam valve is provided, cost can be reduced by reducing the number and weight of the valves.

(3) By adopting the vertical plug valve as the main steam stop valve, the valve stem does not bend at the time of assembling, the adjustment of the contact between the valve seats becomes easy, and the assembling can be performed even by a non-expert assembler. And assembly time can be reduced.

(4) By reducing the size of the integrated steam valve and arranging one integrated steam valve in the high and medium pressure compartment, the arrangement of the integrated steam valve is less restricted, and An arrangement that allows for maintenance of the press room has become possible.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a first embodiment of an integrated steam valve according to the present invention,

FIG. 2 is a partial plan view of a conventional steam turbine provided with an integrated steam valve,

3 is a side view of the integrated steam valve taken along the line AA in FIG. 2,

FIG. 4 is a sectional view showing a conventional main steam stop valve,

FIG. 5 is a diagram showing the opening and closing of a conventional integrated steam valve and the load of a steam turbine. FIG.
FIG. 5 (b) is a diagram showing a 70% load at 0% load and two steam valves of one set of steam control valves fully open.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st steam control valve 2 2nd steam control valve 3 main steam stop valve 31 main valve 32 valve rod 4 valve room 41 valve room diameter 5 actuator 6 main steam inlet 61 valve seal 62 steam passage 01 high-intermediate-pressure car room 02 main Steam stop valve 03 Steam control valve 04 Valve room 05 Front bearing stand 06 Outer garment 07 Intercept valve 08 Reheat steam stop valve 09 Main steam inlet 010 Actuator

Claims (1)

[Claims] 1. An integrated steam valve in which a main steam stop valve and a plurality of steam control valves are incorporated into an integrated valve chamber and are operated, wherein a main steam inlet disposed at both ends of the valve chamber is provided. The main steam stop valve for controlling the flow of main steam into the valve chamber by contacting the provided valve seats by descending the respective valve rods, and three are arranged in series between the valve seats. A first steam control valve disposed substantially at the center of the valve chamber whose interior is expanded, and valves disposed on both sides of the first steam control valve, each having a smaller valve throat diameter than the first steam control valve. An integrated steam valve comprising: a steam control valve including a second steam control valve having a throat diameter; and a single steam control valve provided in a high-to-medium pressure cabin of a steam turbine.