JPH05240406A - Patch for water chamber partition for high pressure feed water heater - Google Patents

Abstract

PURPOSE:To prevent damages of a patch for blocking the cutting for welding inspection of a water chamber partition plate in a high pressure feed water heater in a thermal power or nuclear power plant. CONSTITUTION:The plate thickness of a patch 12 is made thinner as much as possible in a value within a range in which the patch can stand differences in pressure between both sides of a water chamber partition plate 7'. The patch 12 is formed into a traylike shape at its head part and a quarter-cylindrical shape at its trunk section. The cutting at both the ends of the water chamber partition plate 7' is cut up to the upper surface of a tube plate 2 in order to make the patch 12 longer in its longitudinal direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shape of a plate for closing a welding inspection cut of a water chamber partition plate of a high-pressure feed water heater.

[0002]

2. Description of the Related Art In a thermal power plant or a nuclear power plant, condensed water condensed by a condenser is used as a feed water for a boiler or
Before introducing to the reactor steam generator, it is introduced into the feed water heater and preheated by steam turbine extraction. By increasing the temperature of the water supply and running the regeneration cycle in this way, the thermal efficiency of the plant is improved. The feed water heater is generally composed of a low pressure feed water heater and a high pressure feed water heater. The former is arranged upstream of the main feed water pump and the latter is arranged downstream thereof.

FIG. 9 is a vertical sectional side view showing an example of a water chamber portion of a conventional high-pressure feed water heater, FIG. 10 is a front view showing only the water chamber partition plate (7) in FIG. 9, and FIG. 9 XI-
FIG. 12 is a vertical sectional front view taken along the line XI, FIG. 12 is a horizontal sectional view taken along the line XII-XII in FIG. 11, and FIG. 13 is a perspective view showing only the contact plate (13) in FIG.

First, in FIG. 9, a hemispherical water chamber cover (3) is welded to the water chamber A side (upper surface) of the tube sheet (2). This water chamber cover (3) has a water supply inlet nozzle (4),
The water supply outlet nozzle (5) and the manhole (6) are welded. (7) is a water chamber partition plate that divides the water chamber A into an inlet water chamber and an outlet water chamber, and is formed by a lower vertical plane (7a) and an upper inclined plane (7b), and its boundary Notches B for welding inspection as shown in FIG. 10 are provided at both ends of the fold portion D. The water chamber partition plate (7) is welded to the tube plate (2) and the water chamber cover (3). The water chamber partition plate (7) is also provided with a removable cover (8) for maintenance and inspection. After the welding inspection in the water chamber is completed, the cut B for welding inspection is shown in FIG.
Or, as shown in FIG. 13, it is closed by a contact plate 13 in the shape of a bent flat plate. This contact plate 13 is a tube plate (2),
The entire circumference is welded to the water chamber cover (3) and the water chamber partition plate (7).

A cylinder (9) is welded to the side (C) of the tube sheet opposite to the water chamber. The cylinder (9) has a heating steam inlet nozzle (10), a drain outlet, and an air vent (shown in the figure). No) etc. are attached by welding. An end plate (not shown) is welded and closed at the end of the body (9). The heating tube (11) is fixed to the tube plate (2) by expansion, and the other end thereof freely contracts and moves to form a U tube that withstands high pressure.

[0006]

The water chamber partition plate of the conventional high pressure feed water heater has the following problems. 1) At the water chamber partition plate mounting location, the tube plate is deformed and large stress is generated due to the water supply partition plate differential pressure, water supply pressure, heating steam temperature, etc. Especially in the high-pressure feed water heater of a thermal power unit with high pressure, the generated stress is large. For this reason, the flat plate contact plate attachment portion having a short welding leg length cannot follow the deformation and may be damaged. 2) In addition, DSS (Daily Star) of recent thermal power plants
T & Stop), fatigue due to thermal shock easily occurs,
Therefore, the plate is likely to be damaged. 3) When this plate is damaged, the water supply bypasses from the water supply inlet side to the water supply outlet side due to the pressure difference on both sides of the water chamber partition plate, which lowers the plant thermal efficiency.

[0007]

In order to solve the above-mentioned conventional problems, the present invention divides a hemispherical water chamber provided at the top of a vertical high-pressure feed water heater into an inlet water chamber and an outlet water chamber. A partition plate formed by a lower vertical plane and an upper inclined plane, the inclined plane is cut in a quarter circle shape at both ends of the boundary between the vertical plane and the inclined plane, and The plane is cut out in a rectangular shape from the above boundary to the tube sheet part, and these notches form the notch for welding inspection, and the head is dish-shaped and the body part is formed in 1/4 cylindrical shape, respectively. The contact plate is abutted against the cut after the welding inspection, and the entire periphery of the contact plate is welded to the partition plate, the tube plate and the water chamber cover. It proposes a room partition board.

[0008]

In the present invention, the plate is made of a thin plate,
The shape of the head is dish-shaped, the body is 1/4 cylindrical, and the welding inspection cut of the water chamber partition plate is extended to the tube plate surface. This plate flexibly follows the deformation of the tube sheet due to factors such as the bellows of expansion joints. Therefore, the stress generated at the plate mounting portion due to the deformation of the tube sheet is reduced, and the possibility of damage to the portion can be reduced.

[0009]

FIG. 1 is a vertical sectional side view showing a water chamber portion of a high pressure feed water heater to which an embodiment of the present invention is applied, and FIG. 2 shows only the water chamber partition plate (7 ') in FIG. 3 is a vertical sectional view taken along the line III-III of FIG. 1, FIG. 4 is a horizontal sectional view taken along the line IV-IV of FIG. 3, and FIG. 5 is a perspective sectional view taken along the line VV of FIG. 6 is a view in which only the contact plate (12) in FIG. 5 is taken out and viewed in the direction of arrow VI-VI, FIG. 7 is a view in the direction of VII-VII in FIG. 6, and FIG. 8 is a view in the direction of VIII-VIII in FIG. It is a figure. In these figures, the same parts as those of the conventional one described with reference to FIGS. 9 to 13 are given the same reference numerals to avoid redundancy, and detailed description thereof is omitted.

In this embodiment, the water chamber partition plate (7 ')
The inclined plane (7b ') is 1 at both ends of the boundary line D'between the vertical plane (7a') and the inclined plane (7b ') forming the
/ 4 cylindrical notch, the vertical plane (7a ') is notched rectangularly from the boundary D'to the tube sheet (2),
The notches form a cut B'for welding inspection. Then, a contact plate (12) made of a thin plate and having a dish-like head portion and a 1/4 cylindrical shape in the body portion is brought into contact with the cut B'after the welding inspection, and the contact plate (12). Is welded to the partition plate (7 '), the tube plate (2) and the water chamber cover (3).

As described above, in this embodiment, the contact plate (1
2) is made of thin plate and its head is dish-shaped,
Body part is formed in 1/4 cylindrical shape, and water chamber partition plate (7 ')
Since the notch B'for welding inspection of the above is extended to the upper surface of the tube sheet (2), the tube sheet (2) due to the differential pressure between both surfaces of the water chamber partition plate (7 '), the water supply pressure of the high-pressure feed water heater, the heating steam temperature, etc. ), The contact plate (12) flexibly follows the bellows of the expansion joint. Therefore, the stress generated at the portion where the contact plate (12) is attached due to the deformation of the tube sheet (2) is reduced, and the possibility of damage to the portion can be reduced. Moreover, compared with the conventional flat plate (13), there is no significant difference in material cost and working cost, and therefore the burden of improvement is not increased. Further, by making the notch for welding inspection larger, there are secondary effects such as facilitating welding inspection.

[0012]

According to the present invention, the following effects can be obtained. 1) Since the plate can sufficiently follow the deformation of the tube plate due to the differential pressure of the water chamber partition plate, the water supply pressure, the heating steam temperature, etc., the stress generated at the plate part can be reduced and damage to the plate can be prevented. It can be prevented. 2) Compared with the conventional contact plate formed by a flat plate, there is no significant difference in material cost and work cost, and therefore the burden of improvement is not increased. 3) There are secondary effects, such as making the welding inspection easier than before by increasing the depth of the welding inspection.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a water chamber portion of a high-pressure feed water heater to which an embodiment of the present invention is applied.

FIG. 2 is a front view showing only the water chamber partition plate shown in FIG.

3 is a vertical sectional front view taken along the line III-III in FIG.

FIG. 4 is a horizontal sectional view taken along the line IV-IV in FIG.

5 is a perspective cross-sectional view taken along the line VV of FIG.

FIG. 6 is a view showing only the contact plate in FIG. 5 taken out and viewed in a VI-VI direction.

7 is a view taken along the line VII-VII in FIG.

FIG. 8 is a view on arrow VIII-VIII of FIG. 7.

FIG. 9 is a vertical cross-sectional side view showing an example of a water chamber portion of a conventional high-pressure feed water heater.

FIG. 10 is a front view showing only the water chamber partition plate in FIG. 9 taken out.

11 is a vertical sectional front view taken along the line XI-XI of FIG.

12 is a horizontal sectional view taken along the line XII-XII of FIG.

FIG. 13 is a perspective view showing only the contact plate in FIG.

[Explanation of symbols]

 (2) Tube plate (3) Horizontal cover (4) Water inlet inlet nozzle (5) Water outlet outlet nozzle (6) Manholes (7), (7 ') Water chamber partition plate (8) Cover (9) Body (10) ) Heating steam inlet pipe stub (11) Heating pipe (12), (13) Plate A Water chamber B, B'Welding inspection notch D, D'Water chamber partition plate fold

Claims (1)

[Claims] 1. A partition plate for partitioning a hemispherical water chamber provided at the top of a vertical high-pressure feed water heater into an inlet water chamber and an outlet water chamber is formed by a lower vertical plane and an upper inclined plane. At the both ends of the boundary between the vertical plane and the inclined plane, the inclined plane is cut in a quarter circle shape, and the vertical plane is cut in a rectangular shape from the boundary to the tube sheet portion.
The cutouts form the cuts for welding inspection, and the thin plate made of a plate-shaped head and the body of 1/4 cylindrical shape are abutted against the cuts after the welding inspection. The water chamber partition plate of the high-pressure feed water heater, wherein the entire periphery of the contact plate is welded to the partition plate, the tube plate and the water chamber cover.