JPH04191402A - Overload valve arrangement structure of steam turbine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an overload valve arrangement structure for a steam turbine in which a steam stop valve, a steam control valve, and an overload valve are arranged in the outer peripheral area of a turbine body.

[Prior art]

When introducing steam from a steam supply source such as a boiler to a steam turbine, the steam is controlled by a steam control valve that controls the amount of steam corresponding to each load within the rated load by opening and closing the steam stop valve, and a steam control valve that controls the amount of steam corresponding to each load within the rated load. It is guided into the turbine casing of the turbine body through an overload valve that controls the amount, and drives the turbine rotor to generate power. At this time, there is known a system shown in FIG. 2 in which a steam stop valve, a steam control valve, and an overload valve are arranged in the outer peripheral area of the turbine casing.

In FIG. 2, l is a turbine casing of the turbine body, which surrounds a turbine rotor (not shown). The steam stop valves 2, 3 and the steam control valves 4.5 each have an integral casing 6.7, and are provided facing each other in the outer peripheral area of the turbine casing 1. Steam stop valve 2
．． Each valve 3 has a valve 10 consisting of a valve stem 8 passing through a casing 6.7 and a valve body 9 attached to the valve stem 8, and a valve seat 11 on which the valve body 9 is seated. Note 12.1
3 is a steam inlet for supplying steam from a steam supply source such as a boiler into the steam stop valves 2 and 3, respectively.

The steam control valves 4.5 each include a valve 17 consisting of a valve stem 15 passing through a casing 6.7 and a valve body 16 attached to the valve stem 15, and a valve seat 18 on which the valve body 16 is seated. There is.

Note that the steam outlets of the valve seats 11 of the steam stop valves 2 and 3 communicate with the valve chambers 19 of the steam control valves 4 and 5. Furthermore, introduction pipes 20 and 21 are provided which are connected to the steam outlet of the valve seat A and the opposing steam inlet of the turbine casing 1, and through which steam is introduced into the turbine casing 1 from each of the steam control valves 4 and 5.

The overload valves 22 and 23 are disposed facing the outer peripheral area of the turbine casing 1, and each of the overload valves 22 and 23 has a valve stem 26 passing through the casings 24 and 25 and a valve body attached to the valve stem 26. 27, and a valve seat 29 on which the valve body 27 is seated. In addition, the overload valve 22
．． The 23 valve chambers 34 each communicate with the valve chambers 19 in the steam control valves 4, 5 by connecting pipes 30, 31.

Also, an inlet pipe 32. is connected to the steam outlet of the valve seat 29 of the overload valve 22.23 and the opposing steam inlet of the turbine casing 1, through which steam is guided into the turbine casing 1 from each of the overload valves 22.23. There are 33.

With such a configuration, when the steam stop valves 2 and 3 are opened by operating the valve 10 using a control operator (not shown), steam flowing in from the steam inlet 12.13 flows through the valve seat 11 and passes through the steam control valve 4. , 5. Then, by operating the steam control valve 4.5 using a control device (not shown) to open the valve 17 to an opening corresponding to the load, the steam is transferred to the introduction pipe 20.
21 and an amount of steam corresponding to the load flows into the turbine casing 1 to drive the turbine rotor and generate power.

When the load exceeds the rated load, the overload valves 22 and 23 are opened. That is, if the overload valves 22 and 23 are opened in response to overload by operating the valve 28 using a control operator (not shown), the overload steam amount will cause the valve chambers 19 of the steam control valves 4 and 5 to open. The same amount of steam then flows into the valve chamber 34 of the overload valve 22.23, and the same amount of steam evenly flows into the turbine casing l through the introduction pipe 32.33, and the turbine rotor generates power corresponding to the overload steam amount. .

The reason why the pair of overload valves 22.23 are provided as described above is because if the number of overload valves is reduced to one, the amount of steam flowing through the steam stop valve 2.3 will become unbalanced. This is because the size (amount of steam that can flow) becomes unbalanced.

[Problem to be solved by the invention]

If a pair of overload valves are provided as described above, two overload valves and two introduction pipes for guiding steam from the overload valve to the turbine casing are also required, which increases the installation space around the turbine and increases costs. There is also the problem that the number of people is also increasing.

By the way, the overload valve only needs to introduce overload steam into the turbine casing, and since the two overload valves open at the same time, there is no imbalance in the amount of steam flowing through the pair of steam stop valves. We focused on the fact that if we do this, we can reduce the number of overload valves to one.

An object of the present invention is to provide an overload valve arrangement structure for a steam turbine that can make the arrangement around the turbine compact and reduce costs by reducing the number of overload valves to one.

[Means to solve the problem]

In order to solve the above problems, according to the present invention, a pair of steam stop valves are provided facing each other in the outer peripheral area of a turbine body;
In a steam turbine having an overload valve that guides the overloaded air that has passed through the steam stop valve into the turbine body, a steam pipe is provided that connects the pair of steam stop valves, and the overload valve is installed in the center of the steam pipe. shall be installed.

[Effect]

The overload valve is installed in the center of the steam pipe that connects the pair of steam stop valves, so when the overload valve is opened, the flow from the steam stop valve to the steam pipes located on the left and right sides of the overload valve is The pressure of the steam flowing into the overload valve becomes equal in the left and right steam pipes, and as a result, the amount of steam flowing through the pair of steam stop valves is balanced.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a layout diagram showing the arrangement of an overload valve of a steam turbine according to an embodiment of the present invention. In FIG. 1, parts that are the same as those in the conventional example are given the same reference numerals, and their explanations will be omitted. 1st
What is different from the conventional example in the figure is that the steam stop valves 2 and 3 are connected to the casing 6.7 between the steam control valves 4 and 5,
A steam stop 40 is provided, and an overload valve 41 is provided in the center of the steam pipe 40 through which steam flows from the steam stop valves 2 and 3, and the steam outlet of the valve seat 29 of the overload valve 41 and the steam of the turbine casing l are provided. An introduction pipe 42 is provided which is connected to the turbine casing 1 and through which steam is introduced into the turbine casing 1 from the overload valve 41.

Here, the steam pipe 4 between the steam stop valve 2 and the overload valve 41
0 is the left steam pipe 40a, while the steam control valve 3 and overload valve 4
1 is called a right steam pipe 40b.

With this configuration, steam from the steam supply source flows into the two steam stop valves when the steam stop valves 2 and 3 are opened. When overload steam is required, open the overload valve 41 and the steam stop valves 2 and 3 will be supplied to the left steam pipe 40a.
and the right side steam pipe 40b from the overload valve 41 to the inlet pipe 4.
2 into the turbine casing 1, and the turbine rotor generates power corresponding to the overloaded steam.

In this case, since the overload valve 41 is disposed at the center of the steam pipe, the amount of steam flowing into the overload valve 41 from the steam stop valves 2 and 3 becomes equal.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, by providing an overload valve in the center of a steam pipe connecting a pair of steam stop valves, overload flows to the overload valve via both steam stop valves. Since the load steam amount is equal to G, the size of the pair of steam stop valves can be made equal, and since there is only one overload valve, the arrangement around the turbine can be made compact, which has the effect of reducing costs.

[Brief explanation of the drawing]

FIG. 1 is an arrangement diagram showing the arrangement of overload valves in a steam turbine according to an embodiment of the present invention, and FIG. 2 is an arrangement arrangement diagram showing the arrangement of overload valves in a conventional steam turbine. 1: Turbine casing, 2, 3: Steam stop valve, 22,
23.41: Overload valve, 40: Steam pipe. Representative Patent Attorney Otori Yamaguchi ゛-: Ichinin

Claims (1)

[Claims] 1) In a steam turbine having a pair of steam stop valves disposed opposite to each other in the outer peripheral area of the turbine body, and an overload valve that guides overloaded steam that has passed through the steam stop valves into the turbine body, the pair of steam stop valves An overload valve arrangement structure for a steam turbine, characterized in that a steam pipe is provided to connect the valve, and an overload valve is disposed in the center of the steam pipe.