JPS61228167A - Regulating valve for high temperature and high pressure - Google Patents

Abstract

PURPOSE:To reduce production of thermal stress through uniformization of temperature distribution of the whole of a valve, by a method wherein inner cylinders are disposed in a space part for movement of a valve body and to the inner peripheral wall surface of a fluid outlet passage. CONSTITUTION:An inner valve guide inner cylinder 4, disposed in a space part 13 containing a valve rod 5 and a valve body 3 therein, prevents the wall surface of the valve body 3 from making direct contact with fluid L. An outlet inner cylinder 4a at the lower part of the inner valve guide inner cylinder 4 is disposed in a manner to be protruded all the way through to the fluid outlet passage 21 side and is so formed as to cover a wearing spot. A portion, allowing high thermal stress to be produced, is shared by the inner valve guide inner cylinder and the outlet inner cylinder 4a, and thereby a valve box 1 may endure only an inner pressure. Thus, crack due to the thermal stress is produced earlier on the inner valve guide inner cylinder 4 side and the outlet inner cylinder 4a side than on the valve box 1 side, and this effectuates protection of the valve box 1.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a control valve, and more particularly, to a high-temperature, high-pressure control valve that effectively controls high-temperature, high-pressure fluid.

<Prior art and its problems> For example, in a boiler plant for a thermal power plant, a large number of valve devices are arranged in a piping system to control high temperature and high pressure fluid. Due to the growth in nuclear power generation, boilers for thermal power plants are being used to generate power for Heath Road, and boilers for thermal power plants are shifting to thermal power plants that handle intermediate load operations. Thermal power plants responsible for this intermediate load thermal power generation are rarely operated at full load, and many are operated at 75% load, then 50% load, or stopped at high frequency. Start and stop (Daily Start 5top or below is simply DS
In order to improve the efficiency of the entire plant, there is a tendency for the plant to have a large capacity and high pressure.

For this reason, regulating valves that control fluid flow are required to be thicker and larger to withstand high pressure. However, large, thick-walled valves have the disadvantage that thermal stress is generated in the materials that make up the valve due to load fluctuations, resulting in damage to the valve or malfunction. For this reason, many small valves that are less affected by thermal stress are currently installed at the expense of economic efficiency. This not only reduces economic efficiency, but also complicates the control system and reduces reliability.

Here, many angle-type valves are used at high temperatures and high differential pressures, but in this type of valve, the direction of fluid flow is approximately 90 degrees.
The fluid flow path is formed to have a substantially key shape for 0 degree conversion. In this case, Figure 2 shows the temperature distribution isotherm curve at the hot start of the boiler.
0 is shown in 5°C intervals. As described above, thermal stress of up to 490° C. is intensively generated in the thick-walled, acute-angled portion shown in part (A) of FIG. 2 and in the part shown in part (B) of the same figure.

When the valve body 6 is further raised to bring the valve into the "open" state,
As shown in FIGS. 3 and 4, the fluid flow path is changed from the fluid inlet passage 23 to the fluid outlet passage 21, and while reaching the outlet side, the fluid flow is mainly caused by inertia, and the fluid flow is centered around the axis of the fluid outlet passage 21. 22 and violently collides with part 11 in FIG. 3, causing wear.

As mentioned above, conventional valves have structural problems, and the plant must be operated in accordance with the strength of the valve, which poses problems in terms of efficient plant operation.

OBJECTS OF THE INVENTION The present invention has been constructed in view of the above-mentioned problems.The present invention has been constructed in view of the above-mentioned problems. The purpose is to provide a control valve for

Summary of the Invention In short, the present invention installs an inner cylinder inside the valve box that constitutes the valve device main body to prevent fluid from coming into direct contact with the valve box, thereby making the temperature distribution of the entire valve uniform. This is a high-temperature, high-pressure control valve configured to reduce the occurrence of thermal stress.

Kumi Example Examples of the present invention will be described below.

In FIG. 1, 1 is the valve body of the valve body, 2 is the valve seat, and 3 is the valve body. Reference numeral 4 denotes an inner valve guide inner cylinder arranged in a space 13 that accommodates the valve stem 5 and the valve body 6 in the valve body 1, so that the wall surface of the valve body 1 is covered by the inner valve guide inner cylinder 4. Prevents direct contact with the fluid stream. 6 is the valve stem guide, 7
8 is the ground backing, and 8 is the inner valve guide inner cylinder 4 and valve box 1.
The bridge backing is disposed between the upper part of the bridge backing, and 10 is a backing presser. Further, the lower part of the inner valve guide inner cylinder 4 is arranged to protrude to the fluid outlet passage 21 side.
The outlet inner cylinder 4α is configured to cover the worn portion shown in part (c) of FIGS. 3 and 4. In this configuration, the inner valve guide inner cylinder 4 and the outlet inner cylinder 4α are all integrally formed. In addition, the code 9 indicates the inner cylinder 4 and the valve box 1.
This is a gasket that maintains adhesion with the

The broken lines in FIG. 2 indicate the inner valve guide inner cylinder 4 and the outlet inner cylinder 4α, and the parts where the isothermal lines 20 are concentrated ((→ section, (section)
That is, since the portion where large thermal stress is generated is shared by the inner valve guide inner cylinder 4 and the outlet inner cylinder 4α, the valve box 1 only needs to withstand the internal pressure.

Therefore, cranking due to thermal stress occurs earlier on the valve box 1 side and on the inner valve guide inner cylinder 4 and outlet inner cylinder 4α side, and these inner valve guide inner cylinders 4 and outlet inner cylinder 4α are Extremely effective for protection.

Incidentally, even if the valve body 3 is worn out and the fluid flows unevenly as shown in FIG. 4, the valve body 1 can be protected by the outlet inner cylinder 4α.

FIG. 5 is a sectional view showing another embodiment of FIG. 1.

In this embodiment, the shape of the inner cylinder 4 is limited to that arranged in the space in which the valve rod 5 moves, the valve seat 2 is a separate and independent valve seat 2α, and the inner cylinder 4b is a separate valve guide. It has a simplified shape. However, the valve seat 2 (Z is the inner cylinder part 2 at the bottom)
α′ is arranged so as to cover the part that wears out. Further, the valve inlet side inner cylinder 12 is arranged also in the fluid inlet passage 26 to equalize the temperature gradient of the valve body 3 and to prevent the inner circumferential wall surface of the fluid inlet passage 26 from being worn out.

Effects> Since the present invention has the above-described configuration, even if the valve is used under high temperature and high pressure by DSS operation, the temperature distribution throughout the valve is uniform, and thermal stress can be prevented from being concentrated locally.

Furthermore, wear due to fluid can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a valve device showing an embodiment of the present invention, FIG. 2 is a sectional view of the valve box showing temperature distribution in the valve box, FIG. 3 is a sectional view of the valve box showing the fluid flow state, and FIG. The figure is a conceptual diagram of fluid flow, and FIG. 5 is a sectional view of a valve device showing another embodiment. 1...Valve box 2...Valve seat 3...Valve
Body 4, 4b...Inner valve guide inner cylinder 12...Valve inlet side inner cylinder 13...Space 21...Fluid outlet passage 23...Liquid inlet passage Fig. 1 Fig. 3 Fig. 5

Claims (1)

[Scope of Claims] 1. A control valve having a space for moving a valve body, a fluid outlet passage communicating with this space, and a fluid inlet passage substantially perpendicular to the space for moving the valve body, wherein A control valve for high temperature and high pressure, characterized in that an inner cylinder is arranged on the inner peripheral wall surface of the space and the fluid outlet passage. 2. The high-temperature, high-pressure control valve according to claim 1, characterized in that an inner cylinder is also arranged on the inner circumferential wall surface of the fluid inlet passage. 3. A patent characterized in that the inner cylinder of the valve body movement space and the inner cylinder of the fluid outlet passage are integrally formed, and the upstream end edge of the inner cylinder of the fluid outlet passage is used as a valve seat. A high temperature and high pressure control valve according to claim 1 or 2.