JPH04203792A - Steam damper - Google Patents

Abstract

PURPOSE:To prevent any occurrence of excessive stress by a method wherein an energy dampening buffle is slidably installed against a buffle supporting structure. CONSTITUTION:Steam 9 fed into a steam damper flows into a spray pipe 1 and further injected out of a steam injection port 7 while its pressure being reduced. Injected steam stream 10 strikes against an installed buffle 2, disperses its energy and blown into a condensor. The spray pipe shows a rapid increasing in its temperature due to flowing-in of steam and at the same time it is thermally expanded and extended in an axial direction and a direction perpendicular to an axis of the pipe. In turn, the spray pipe is supported such that a supporting plate 3 having a hole larger than an outer diameter of the spray pipe is mounted, the spray pipe is passed through the hole and the spray pipe is fixed in such a way as it may be slid by an adjusting plate 4 with a clearance required for a thermal expansion in a direction perpendicular to the axis of pipe. The adjusting plate 4 is welded and fixed to a supporting plate 3. The supporting plate 3 is forcedly welded and fixed to an inner structural member of the condensor so as to receive safely all the forces acting against the spray pipe. Accordingly, a temperature of the spray pipe is rapidly increased due to the flowing steam and even if a thermal expansion is produced at the spray pipe, the pipe is not restricted all and no excessive stress caused by the thermal expansion may occur.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a steam damper in a condenser for a steam turbine power generation plant that introduces steam other than turbine exhaust into the condenser.

[Conventional technology]

As shown in FIGS. 3 and 4, a conventional steam damper has a spray pipe 1 (bypass steam introduction pipe) and a baffle 2 (
The buffer plate (buffer plate) has an integral structure, and in particular, the support plate 3 for fixing the baffle is attached to the baffle at one end and the spray pipe at the other end by welding.

In addition, the baffles and support plates that are subjected to the impact of the steam jet are made of stainless steel or alloy steel to prevent erosion caused by the jet, resulting in high residual stress in the welded area. Due to the inflow, the temperature rises rapidly,
Thermal stress occurs at the weld to the support plate. Similarly, the steam jet impinges on the weld between the baffle and the support plate, causing a sudden rise in temperature and generation of thermal stress.

Residual stress in welds and thermal stress overlap, resulting in high stress in welds that can lead to cracks from minute defects that would not be a problem in normal structures.

Preventing this requires complete welding and residual stress reduction, and specifically requires advanced welding technology and stress-relieving heat treatment, which inevitably increases manufacturing costs. Furthermore, when replacing the baffle etc. due to thinning, etc., it was necessary to replace everything including the spray pipe, which is almost never thinned because it is an integral structure, which required a large amount of construction cost.

[Problem to be solved by the invention]

The above conventional technology does not take into consideration the fact that the thermal stress and residual stress due to the sudden rise in temperature when high-temperature steam flows into the weld zone overlap, resulting in excessive stress, and the problem is that the excessive stress causes cracks to occur from minute defects in the weld zone. was there. Furthermore, since it is an integral structure, even if it becomes necessary to replace a part, the entire structure must be replaced, which requires a large amount of cost, which is uneconomical.

The purpose of the present invention is to create a structure in which the spray pipe and baffle are not fixed and integrated, but are supported individually, allowing them to thermally expand without interfering with each other, and eliminating the need for welded parts that generate excessive stress, which can cause cracks, etc. Our goal is to provide a reliable steam damper that does not.

Another object of the present invention is to prevent erosion of the baffle support member by installing the support member of the baffle on the opposite side of the spray pipe from the steam outlet, that is, on the back side of the baffle when viewed from the steam outlet, thereby increasing the support reliability of the baffle. To provide a highly reliable and economical steam damper in which the length of the baffle is divided into fixed lengths, the baffle is supported by bolts, and the baffle can be easily replaced.

[Means to solve the problem]

In order to achieve the above purpose, the spray pipe and baffle are not connected and fixed by welding, but are supported individually, allowing them to thermally expand freely without interfering with each other, and eliminating welded parts that generate excessive stress. .

In addition, in order to prevent the baffle support member from being eroded by the steam ejected from the spray pipe, the baffle support member is installed on the opposite side of the spray pipe from the steam outlet, that is, on the back side of the baffle when viewed from the steam outlet. This was designed to avoid a direct hit.

Furthermore, in order to make it easier and more economical to replace the baffle, which is easily eroded by direct blows of steam, the baffle is divided into certain lengths, and the baffle is supported and fixed with bolts, so there is no need to remove the whole thing. However, only the baffle can be replaced.

[Effect]

Since the spray tube and the baffle are each supported separately and can thermally expand without interfering with each other, the spray tube is heated by the inflow of high-temperature steam and simultaneously extends freely from its fixed end. Similarly, the baffle freely extends from the fixed end in response to the temperature rise caused by the ejected steam. In this way, they can freely expand thermally without interfering with each other, so no excessive stress is generated.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

As shown in Figures 1 and 2, the structure of the steam damper is that a cylindrical spray pipe 1 with a steam jet lower is located at the center, and the spray pipe faces the jet lower and extends a certain distance from the jet nozzle. A rectangular flat baffle 2 arranged in the axial direction is provided. A reinforcing member 5 is welded to the baffle 2, and an end portion of the reinforcing member 5 is slidably fixed to a supporting member 6 with a bolt (not shown).

The support member 6 is welded and fixed to a structural member 8 inside the condenser (not shown), so that it can safely support all external forces to which the baffle is subjected. The support of the spray tube 1 is slidably fixed to a support plate 3 via an adjustment plate 4. Further, the support plate 3 is welded and fixed to the condenser internal structural member 8, so that it can safely support all the forces acting on the spray pipe.

The steam 9 introduced into the steam damper flows into the spray pipe 1 and is ejected from regularly opened steam ejection lowers at appropriate intervals while being depressurized. The ejected steam flow 10 collides with a baffle 2 installed so as to face the flow direction, disperses energy, and blows out into the condenser. The temperature of the spray pipe increases rapidly due to the inflow of steam, and at the same time, the spray pipe expands thermally and extends in the direction of the pipe axis and in the direction perpendicular to the pipe axis. On the other hand, to support the spray tube, install a support plate 3 with a hole larger than the outer diameter of the spray tube, pass the spray tube through the hole, and adjust it by leaving a gap necessary for thermal expansion in the direction perpendicular to the tube axis. It is slidably fixed by a plate 4. The adjustment plate 4 is welded and fixed to a support plate 3, and the support plate 3 is firmly welded and fixed to an internal structural member of the condenser, so that it can safely receive all the forces acting on the spray pipe. Therefore, even if the temperature of the spray pipe rises rapidly due to the inflowing steam and thermal expansion occurs, the spray pipe is not restrained in any way and can freely extend without interfering with anything else, so excessive stress due to hot tensioning can be avoided. Does not occur.

In addition, as the steam ejected from the steam ejection lower provided in the spray pipe collides with the baffle 2 and the temperature rises rapidly, the baffle 2 stretches in the pipe axis direction and in the direction perpendicular to the pipe axis due to thermal expansion, but as mentioned above, it can be slid. Since it is fixed like this, it is not constrained in any way and can freely expand without interfering with anything else, so excessive stress due to thermal expansion does not occur.

Since the support members 5 and 6 of the baffle are installed on the back side of the baffle so as not to be directly hit by the steam flow 10 emitted from the steam outlet, there is no fear of erosion by the jetted steam, and the service life is dramatically extended. .

Furthermore, because the baffle is divided into fixed lengths that are advantageous for strength and structure, it is susceptible to erosion by steam jets.
If the baffle thins out, it will need to be replaced, but in such cases it can be easily removed and replaced, and only the necessary baffle needs to be replaced, rather than the entire baffle, reducing construction costs. Yes, it is possible to make an economical steam damper.

As described above, according to the present invention, there is no part where excessive stress occurs due to thermal expansion due to the inflow of high-temperature steam (mainly the welded part between the spray pipe and the support member), so cracks may occur due to excessive stress. It has the effect of preventing damage caused by In addition, it has the effect of preventing erosion of the baffle support member, which is important for maintaining function, and also makes it possible to easily replace the baffle, making it possible to provide a highly reliable and economical steam damper. be.

〔Effect of the invention〕

According to the present invention, the spray pipe and the baffle are not connected and fixed, but are supported individually, and can freely expand thermally without being constrained or interfering with each other. This prevents excessive stress from occurring and improves reliability. This has the effect of providing a high steam damper.

Furthermore, since the supporting member of the baffle is installed on the back side of the baffle when viewed from the steam outlet side, it is possible to avoid direct hit by the steam jet, which has the effect of preventing erosion of the supporting member by the steam flow.

Furthermore, since the baffle is divided into predetermined lengths and fixed with bolts, necessary parts can be selectively and easily replaced, which reduces replacement costs and has an economical effect.

[Brief explanation of the drawing]

FIG. 1 is a side view of one embodiment of the present invention, and FIG. 2 is a parent view taken along line AA in FIG. FIG. 3 is a side view of an example of a conventional steam damper, and FIG. 4 is a view taken along the line BB in FIG. 1...Spray pipe, 2...Baffle, 3...Support plate,
4... Adjustment plate, 5... Reinforcement member, 6... Support member, 7... Steam outlet, 8... Condenser internal structural member,
9...Steam flow, second plan #40

Claims (1)

[Claims] 1. In a steam damper comprising a depressurizing spray pipe, a baffle for buffering the energy of steam ejected from the spray pipe, and a fixing member thereof, the energy buffering baffle is attached to a baffle support structure. , a steam damper characterized in that it is slidably mounted. 2. In the steam damper set forth in claim 1,
Energy buffering baffles are installed in the vertical direction of the spray pipe for depressurization, and the upper part of the spray pipe for depressurization is arranged in the order of the baffle and the beam from the side closest to the spray pipe, and the baffle and the beam are arranged in the order of the baffle and the beam from the side closest to the spray pipe on the lower side. A steam damper characterized by being arranged in this order. 3. In the steam damper set forth in claim 1,
A steam damper characterized by an energy buffering baffle divided at a constant pitch in a direction perpendicular to the spray tube axis. 4. The steam damper set forth in claim 1 is characterized in that the portion where the energy buffer baffle is attached to the beam has a hole structure that does not interfere with thermal deformation of the buffer baffle. steam damper.