CN215410499U

CN215410499U - Thermal power plant protects low side valve core safety device

Info

Publication number: CN215410499U
Application number: CN202120633904.3U
Authority: CN
Inventors: 张俊; 张广杰; 武常青; 杨迎伟; 安浩; 黄国生; 赵晨皓; 马金鞍
Original assignee: Huaneng Zuoquan Coal Power Co ltd
Current assignee: Huaneng Zuoquan Coal Power Co ltd
Priority date: 2021-03-29
Filing date: 2021-03-29
Publication date: 2022-01-04
Anticipated expiration: 2031-03-29

Abstract

The utility model discloses a safety device for protecting a low-side valve element of a thermal power plant, which comprises a valve cage, wherein a plurality of groups of through-flow holes are uniformly distributed on the side wall of the valve cage in a surrounding manner, the lower parts of the through-flow holes of the valve cage are modified, a flow limiting block is welded, and the flow direction of steam is changed, so that the steam does not directly scour the sealing surface of the valve element when the opening degree of a valve is lower; a new flow guide hole is formed in the flow limiting block under the condition that the through flow is changed, and part of the flow limiting block enters steam to form turbulent flow, so that the flushing strength of steam fluid on the valve is reduced.

Description

Thermal power plant protects low side valve core safety device

Technical Field

The utility model belongs to the technical field of safety protection devices, and particularly relates to a safety device for protecting a low-side valve core in a thermal power plant.

Background

The supercritical air-cooling coal-fired unit of the 2X660 MW-level engineering in the first stage of the Huanen left-right power plant adopts a BMCR high-low pressure two-stage series bypass system with the capacity of 40%. The low-pressure bypass comprises a low-pressure bypass valve and two sets of a water spraying temperature-reducing regulating valve and an isolating valve. The third-stage temperature and pressure reducing device of the low-pressure bypass comprises two temperature and pressure reducing devices. The low side valve of our factory is produced by imported German Holt adjustment technology combination company Limited and has the following model: 1611-91DN500/800 angle low pressure bypass valve. The design values are: medium pressure 4.0MP α, outlet 1.6MP α. The current #1 unit #1 and #2 has large inner leakage at the low side and has large influence on the heat efficiency of the unit. The sealing surface can be damaged only by starting the machine for many times, the sealing surface leaks from the lower side for a long time after being damaged, and the starting state is not maintainable. After overhauling and disintegration, the valve core and the valve seat are found to have steam scouring signs, and the lower part of the valve cage hole has obvious scouring traces.

The low-side valve is a technical product in 80 and 90 years, the sealing grade is low, the design concept is relatively laggard, and a device for protecting the sealing surface is not designed, so that the sealing surface of the valve is easy to damage. The steam-water quality is poor just after the unit starts, a large amount of wet steam is flushed on the valve core, so that cavitation is easy to generate, and the valve core is leaked just at the beginning. The sealing surfaces of the valve core and the valve seat are in a high-temperature state for a long time, the materials of the sealing surfaces can be correspondingly softened, misalignment and deformation of the valve core and the valve seat are generated, and the sealing performance of the valve is affected. After the machine set is overhauled, impurities exist in a furnace side system pipeline, the machine is started and stopped to impact a main valve and a sealing surface of a pre-opened valve, foreign matters are possibly mixed between a valve core and a valve seat after the valve is closed, and the valve core and the valve seat are damaged and sealing lines are not connected. Due to the reasons, the low side sealing surface increases the operation cost and is not beneficial to the stable operation of the unit.

Disclosure of Invention

The utility model aims to overcome the technical problem of the existing manufacturing defects and provides a safety device for protecting a low-side valve element in a thermal power plant, so as to solve the problems that a low-side sealing surface is easy to damage and not easy to maintain in the background technology.

In order to achieve the purpose, the utility model provides the following technical scheme: the utility model provides a low side valve core safety device of thermal power plant protection, includes the valve cage, encircles evenly arranged on the lateral wall of valve cage and has the through-flow hole of multiunit, its characterized in that: the welding of the below in through-flow hole has the current-limiting piece that changes wet steam and directly erode at the case, sets up the water conservancy diversion hole that can produce the vortex on the current-limiting piece, the fluid that the water conservancy diversion hole set up the fluid that passes through can produce the vortex effect to the fluid that the through-flow hole set up to pass through.

Furthermore, the inside and outside walls of the valve cage are provided with annular ribs below the diversion holes, and the outside wall of the upper port of the valve cage is also provided with annular ribs.

Further, the area of the through flow hole is far larger than that of the flow guide hole.

Further, the valve cage is trumpet-shaped from bottom to top.

Compared with the prior art, the utility model provides a device for protecting the sealing surface of the valve core in a thermal power plant, which has the following beneficial effects:

1. the utility model sets the diversion block with the same material to divert the medium, to reach the same strength, hardness and toughness, to protect the sealing surface of valve;

2. the utility model reduces the flow area to change the direction of the fluid, so that the fluid is not directly flushed on the sealing surface of the valve, and the steam which is originally and directly impacted on the sealing surface by the fluid directly changes the flow direction, so that the sealing surface is prevented from being directly flushed, the sealing surface is protected, the possibility of overhauling is reduced, and the overhauling period is prolonged;

3. the flow guide holes are arranged in the valve body, so that the valve body has a new flow direction, the two flowing fluids collide in the cavity to reduce the kinetic energy of the two flowing fluids and achieve a turbulent flow effect, the original flow flows from the upper part to the lower part of the valve, the existing flow guide holes intervene in the flowing process of the original flow guide holes and change the kinetic energy of the original flow guide holes to achieve the turbulent flow effect, and therefore the sealing surface of the valve is protected.

Drawings

FIG. 1 is a schematic perspective view of an embodiment of the present invention;

FIG. 2 is a top view of an embodiment of the present invention;

FIG. 3 is a side view of an embodiment of the present invention;

FIG. 4 is a perspective view of section line A-A of FIG. 2;

FIG. 5 is a schematic diagram of an embodiment of the present invention;

FIG. 6 is a prior art schematic of an embodiment of the present invention.

In the figure: the valve cage is 1, the through flow hole is 2, the flow guide hole is 3 and the flow limiting block is 4.

Detailed Description

The following describes a specific embodiment of the present invention with reference to the drawings.

As shown in fig. 1 to 5, a safety device for protecting a low-side valve element in a thermal power plant comprises a valve cage 1, wherein a plurality of groups of through flow holes 2 are uniformly arranged on the side wall of the valve cage 1 in a surrounding manner, and the safety device is characterized in that: the welding of the below of through-flow hole 2 has the current-limiting piece 4 that changes the wet steam and directly erode at the case, sets up the water conservancy diversion hole 3 that can produce the vortex on current-limiting piece 4, the fluid that water conservancy diversion hole 3 set up the fluid that passes through can produce the vortex effect to the fluid that through-flow hole 2 set up the pass through.

Preferably, the inner side wall and the outer side wall of the valve cage 1 are provided with annular ribs below the diversion holes 3, and the outer side wall of the upper port of the valve cage 1 is also provided with annular ribs.

Preferably, the area of the through-flow opening 2 is much larger than the area of the guide opening 3.

Preferably, the valve cage 1 is trumpet-shaped from bottom to top.

Referring to fig. 4 and 6, the working principle is as follows: the lower part of a through-flow hole 2 of a valve cage 1 is modified, a flow limiting block 4 is welded, and the flow direction of steam is changed, so that the sealing surface of a valve core is not directly flushed when the opening of the valve is low; a new flow guide hole 3 is formed in the flow limiting block 4 under the condition that the through flow is changed, and part of the flow guide hole enters steam to form turbulent flow, so that the flushing strength of steam fluid on the valve is reduced.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the utility model, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a thermal power plant protects low side valve core safety device, includes valve cage (1), encircles evenly arranged on the lateral wall of valve cage (1) and has the through-flow hole (2) of multiunit, its characterized in that: the welding of the below of through-flow hole (2) has the restriction piece (4) of avoiding wet steam to directly erode at the case, offers water conservancy diversion hole (3) that can produce the vortex on restriction piece (4), through the fluid in water conservancy diversion hole (3) can be realized producing the vortex effect to the fluid through-flow hole (2).

2. A thermal power plant low side bypass spool safety device as claimed in claim 1, wherein: the inside and outside lateral wall of valve cage (1) is equipped with annular bead in the below department of water conservancy diversion hole (3), also be equipped with annular bead on the lateral wall of the last port of valve cage (1).

3. A thermal power plant low side bypass spool safety device as claimed in claim 2, wherein: the area of the through flow hole (2) is far larger than that of the flow guide hole (3).

4. A thermal power plant low side bypass valve core safety device as claimed in any one of claims 1 to 3, wherein: the valve cage (1) is trumpet-shaped from bottom to top.