JPH10170169A - Condenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discharge a drain condensed and liquefied by a tube bundle for air cooling to a hot well without contact with a pipe bindle for steam cooling. SOLUTION: A pipe bundle 4 is arranged in a space between an upper pipe bindle 2A for steam cooling and a lower pipe bundle 2B for steam cooling. A drain condensed and liquefied by the pipe bundle 4 for air cooling is accumulated into a drain reservoir 7 and discharged to a hot well 5 through a drain discharge pipe 8 from drain reservoirs 7A and 7B. Thus, the drain with a higher concentration of ammonia accumulated in the drain reservoirs 7A and 7B is discharged by a drain discharge pipe 8 without contacting the lower pipe bundle 2B for steam cooling thereby enabling prevention of corrosion of the lower pipe bundle 2B for steam cooling as caused by ammonia attack.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condenser, and more particularly to a condenser for condensing and liquefying exhaust steam from a steam turbine used in a thermal or nuclear power plant.

[0002]

2. Description of the Related Art A steam turbine used in a thermal power plant or a nuclear power plant or the like works there and sends out expanded steam to a surface contact condenser. The turbine exhaust steam flowing into the condenser is exchanged with cooling water such as seawater or river water in a cooling pipe and is condensed and recovered.

FIG. 7 shows a conventional condenser, in which a steam cooling pipe bundle 2 is arranged in a condenser body 1, and the steam cooling pipe bundles 2 extend in parallel with each other and in a horizontal direction. It consists of a number of steam cooling pipes. The steam cooling tube bundle 2 is divided into an upper steam cooling tube bundle 2A and a lower steam cooling tube bundle 2B, and a space between the upper steam cooling tube bundle 2A and the lower steam cooling tube bundle 2B is an enclosing plate. An air cooling tube bundle 4 is disposed inside the surrounding plate 3. The air cooling pipe bundle 4 is composed of a number of air cooling pipes extending in parallel with each other and in the direction in which the steam cooling pipe extends, and cools non-condensable gas such as air and ammonia contained in turbine exhaust steam. In the lower part of the condenser body 1,
A hot well 5 is provided for collecting and discharging the drain condensed and liquefied by the steam cooling tube bundle 2 and the air cooling tube bundle 4.

[0004] Turbine exhaust steam discharged from the steam turbine enters the condenser body 1, flows into the inside of the steam cooling pipe bundle 2 from the outer periphery thereof, and is condensed and liquefied on the surface of each steam cooling pipe for air cooling. It flows toward the tube bundle 4. The drain condensed and liquefied by the steam cooling tube bundle 2 is dropped into the hot well 5 from there. Since the turbine exhaust steam contains ammonia gas, the ammonia concentration gradually increases as the steam condenses and liquefies in each steam cooling pipe. The high ammonia concentration turbine exhaust steam is further condensed and liquefied on the surface of the air cooling pipe of the air cooling tube bundle 4 to generate a high ammonia concentration drain. The drain having a high ammonia concentration is also dropped from the air cooling tube bundle 4 to the hot well 5.

[0005] Incidentally, a copper alloy-based material is generally used for the steam cooling tube of the steam cooling tube bundle 2, and the cooling tube of the copper alloy-based material has a high ammonia concentration drain due to a phenomenon called ammonia attack. Severely corroded by
For this reason, a titanium material having excellent corrosion resistance is generally used for the air cooling tubes of the air cooling tube bundle 4.

[0006]

However, in the conventional condenser, the high ammonia concentration drain condensed and liquefied by the air cooling pipe bundle 4 flows down while contacting the steam cooling pipe of the lower steam cooling pipe bundle. Therefore, there is a problem that the steam cooling pipe of the lower steam cooling pipe bundle may be corroded by the high ammonia concentration drain. Such a problem similarly occurs when the turbine exhaust steam contains a corrosive gas other than ammonia.
Accordingly, an object of the present invention is to provide a condenser capable of discharging drain condensed and liquefied by a bundle of air cooling tubes to a hot well without contacting the bundle of steam cooling tubes.

[0007]

In order to achieve this object, the present invention is directed to a steam cooling system comprising a plurality of steam cooling cooling pipes extending in parallel with each other and in a substantially horizontal direction. Tube bundle, an enclosing plate surrounding a space formed at the center in the vertical direction of the steam cooling tube bundle, and disposed inside the enclosing plate, parallel to each other and in the extending direction of the steam cooling tube bundle. An air cooling tube bundle including a number of air cooling cooling tubes extending along the drain; a drain disposed below the steam cooling tube bundle and condensed and liquefied by the steam cooling tube bundle and the air cooling tube bundle. And a hot well for collecting the water, the drain being provided in a lower part of the space, extending along the extending direction of the air cooling tube bundle, and being condensed and liquefied by the air cooling tube bundle. Dre A reservoir and an upper end communicating with the drain reservoir, penetrating a lower portion of the steam cooling tube bundle so that a lower end thereof is positioned lower than a lower end of the steam cooling tube bundle, and draining the drain reservoir into the steam cooling tube bundle; And a drain discharge pipe for discharging the hot well without contacting the hot well.

The drain condensed and liquefied by the air cooling tube bundle drops into the drain reservoir, and is discharged from the drain reservoir to the hot well through a drain discharge pipe penetrating a lower portion of the steam cooling tube bundle. Therefore, the drain containing the corrosive substance such as ammonia at a high concentration is discharged to the hot well without coming into contact with the steam cooling tube bundle, so that corrosion of the steam cooling tube bundle can be prevented.

According to a second aspect of the present invention, in the condenser according to the first aspect, a lower end of the drain discharge pipe is located in a drain in the hot well. . Since the lower end of the drain pipe is located in the drain in the hot well, it is possible to prevent the vapor from flowing back in the drain pipe. That is, if the lower end of the drain discharge pipe is open to the air at the lower end of the steam cooling pipe bundle, the steam pressure around the steam cooling pipe bundle becomes larger than the pressure around the drain reservoir. May flow backward in the drain discharge pipe, but by positioning the lower end of the drain discharge pipe in the drain in the hot well, this back flow of the vapor is prevented.

According to a third aspect of the present invention, in the condenser according to the first aspect, the drain discharge pipe has a substantially U-shaped portion extending downward from a lower end of the steam cooling pipe bundle. It is characterized in that it is bent upward like a letter. Drain is accumulated in a U-shaped bent portion formed at the lower end portion of the steam cooling tube bundle, and the drain accumulated in the U-shaped bent portion prevents steam from flowing backward in the drain discharge pipe. Can be.

According to a fourth aspect of the present invention, in the condenser according to the first aspect, the steam cooling tube bundle and the steam cooling tube bundle are provided at predetermined intervals along an extending direction of the steam cooling tube bundle. While supporting the air-cooling tube bundle, a plurality of cooling tube support plates extending vertically so as to divide the drain reservoir, and the plurality of cooling tube support plates so as to communicate the divided drain reservoir. And at least one of the drain communication holes.

Since the drain reservoir is communicated with the drain communication hole of the cooling pipe support plate, the number of drain discharge pipes can be reduced. The terms of the cooling pipe for steam cooling and the cooling pipe for air cooling used in the present specification will be described below.

The turbine exhaust steam introduced into the condenser contains non-condensable gas such as air and ammonia in addition to steam. The cooling pipe for steam cooling has a purpose of mainly cooling and condensing and liquefying the steam in the turbine exhaust steam introduced into the condenser, while the cooling pipe for air cooling has a purpose of cooling the steam. The turbine exhaust steam cooled by the cooling pipe is further cooled, and this cooling sufficiently cools not only steam in the turbine exhaust steam but also non-condensable gas such as air and ammonia. Therefore, the steam cooling pipe should not be construed as selectively cooling only the steam in the turbine exhaust steam, and similarly the air cooling pipe should selectively only the air in the turbine exhaust steam. It should not be interpreted as cooling.

Also, the steam cooling tube bundle and the air cooling tube bundle used in the present specification respectively mean a tube group in which the steam cooling cooling tube and the air cooling cooling tube defined above are bundled. It is.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a condenser according to the present invention will be described below with reference to FIGS. 1 to 6 in which the same parts as those in FIG.

FIGS. 1 to 3 show a first embodiment of the present invention, in which a steam cooling pipe bundle 2 is disposed in a condenser body 1, and the steam cooling pipe bundles 2 are parallel to each other. And a number of steam cooling tubes extending in the horizontal direction. The steam-cooling tube bundle 2 is divided into an upper steam-cooling tube bundle 2A and a lower steam-cooling tube bundle 2B. An air cooling tube bundle 4 is disposed inside the surrounding plate 3. The air cooling tube bundle 4 is composed of a number of air cooling tubes extending in parallel with each other and in the direction in which the steam cooling tubes extend, and cools non-condensable gas such as air and ammonia contained in turbine exhaust steam. Condenser body 1
A hot well 5 for collecting and discharging drain condensed and liquefied by the steam cooling tube bundle 2 and the air cooling tube bundle 4 is provided at a lower portion of the hot well 5.
Is provided.

As clearly shown in FIG. 2 and FIG.
A drain drop prevention plate 6 is provided upright on the lower surface of the enclosure, and a lower portion of the enclosure plate 3 and the drain fall prevention plate 6 are provided with left and right drain reservoirs 7 for storing drain dropped from the air cooling tube bundle 4.
A and 7B. These left and right drain reservoirs 7A,
A drain discharge pipe 8 is connected to each of the drain discharge pipes 7B. The upper end of each drain discharge pipe 8 has a drain fall prevention plate 6 as shown in FIG.
Through the drain reservoirs 7A and 7B. In addition,
1 to 3, only the drain discharge pipe 8 connected to the left drain reservoir 7A is shown, but the drain discharge pipe 8 is similarly connected to the right drain reservoir 7B. The drain discharge pipe 8 extends in the up-down direction, penetrates the lower steam cooling pipe bundle 2B and the short path prevention plate 9 provided in the lower steam cooling pipe bundle 2B, and forms the steam cooling pipe bundle 2B. Projecting from the lower end, and the lower end is immersed in the drain in the hot well 5.

As shown in FIG. 3, a cooling pipe supporting plate 10 extends in the vertical direction, and the cooling pipe supporting plate 10 supports the steam cooling pipe bundle 2, the surrounding plate 3, and the air cooling pipe bundle 4. ing.

Next, the operation of the first embodiment will be described.

The turbine exhaust steam discharged from the steam turbine flows into the steam cooling pipe bundle 2 from the outer periphery thereof and flows toward the air cooling pipe bundle 4 while being condensed and liquefied on the surface of each steam cooling pipe. The drain condensed and liquefied by the steam cooling tube bundle 2 is dropped into the hot well 5 from there. Since the turbine exhaust steam contains ammonia gas, the ammonia concentration gradually increases as the steam condenses and liquefies in each steam cooling pipe. The high ammonia concentration turbine exhaust steam is further condensed and liquefied on the surface of the air cooling pipe of the air cooling tube bundle 4 to generate a high ammonia concentration drain. The drain having a high ammonia concentration is dropped from the air-cooling tube bundle 4 to the left and right drain reservoirs 7A and 7B and accumulated there. The drain having a high ammonia concentration stored in the drain reservoirs 7A and 7B is discharged to the hot well 5 through the drain discharge pipe 8.

The drain having a high ammonia concentration in the drain reservoirs 7A and 7B condensed and liquefied on the surface of the air cooling tube of the air cooling tube bundle 4 does not contact the lower steam cooling tube bundle 2B at all. Since the water is directly discharged to the hot well 5 through the discharge pipe 8, the lower steam cooling pipe bundle 2B can be prevented from being corroded by the ammonia attack. The lower end of the drain pipe 8 is connected to the hot well 5.
Since it is immersed in the drain inside, even if the steam pressure around the outside of the steam cooling tube bundle 2 is higher than the pressure of the drain reservoir 7, the steam does not flow backward in the drain discharge tube 8.

The shroud plate 3 and the drain discharge pipe 8 which come into contact with the drain having a high ammonia concentration are made of a material having excellent corrosion resistance, such as titanium, similarly to the air cooling pipe bundle 4. FIGS. 4 and 5 show a second embodiment of the present invention, in which a plurality of vertically extending cooling tube support plates 10 extend in the direction in which the steam cooling tube bundle 2 extends, that is, in the longitudinal direction. Are provided at predetermined intervals. These cooling tube support plates 10 support the steam cooling tube bundle 2, the surrounding plate 3, and the air cooling tube bundle 4, and also include a plurality of drain reservoirs 7 extending in the longitudinal direction of the steam cooling tube bundle 2. Divide into drain reservoir sections 7a, 7b, 7c, 7d.

A drain communication hole 11 is formed in the cooling pipe support plate 10 for separating the drain reservoir sections 7a and 7b.
The drain communication hole 11 connects the drain reservoir section 7a and the drain reservoir section 7b. Similarly, the cooling pipe support plate 10 that separates the drain reservoir sections 7c and 7d.
A drain communication hole 11 is also formed in the drain communication hole 1.
Numeral 1 connects the drain reservoir section 7c and the drain reservoir section 7d. Also, a drain discharge pipe 8 is provided in the drain reservoir section 7a and the drain reservoir section 7c, respectively.
Is communicated. Other configurations are the same as those of the first embodiment. The arrow shown in FIG.
Represents the flow of the drain condensed and liquefied.

With such a configuration, the drain collected in the drain storage section 7a and the drain storage section 7c flows into the drain discharge pipe 8, and is discharged to the hot well 5 through the drain discharge pipe 8. The drain accumulated in the drain reservoir section 7b and the drain reservoir section 7d flows into the drain reservoir section 7a and the drain reservoir section 7c through the drain communication hole 11, respectively.
Is discharged.

As described above, the number of the drain discharge pipes 8 connected to the drain reservoir section can be reduced by piercing the drain communication holes 11 in the predetermined cooling pipe support plate 10.

FIG. 6 shows a third embodiment of the present invention. The drain discharge pipe 8 has a lower end portion, that is, a lower end portion 8a protruding downward from the lower steam cooling tube bundle 2B. It bends into a shape and the lower end of the drain discharge pipe 8 faces upward,
It is open in the air. Other configurations are the same as those of the second embodiment.

With such a configuration, the drain reservoir 7
Drains from the lower end through the drain discharge pipe 8 and falls into the hot well 5. Since the drain flowing from the drain reservoir 7 is always stored in the U-shaped bent portion 8a at the lower end portion of the drain discharge tube 8, the drain discharge tube 8
The backflow of steam can be prevented even though the lower end of the airbag is open in the air.

[0028]

As is apparent from the above description, according to the present invention, the drain condensed and liquefied by the air cooling tube bundle is stored in the drain reservoir, from which it contacts the steam cooling tube bundle by the drain discharge tube. Therefore, the steam cooling tube bundle can be prevented from being corroded by the drain containing the corrosive substance such as ammonia at a high concentration.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a first embodiment of a condenser according to the present invention.

FIG. 2 is an enlarged sectional view showing a main part of the first embodiment.

FIG. 3 is an enlarged perspective view showing the periphery of the air cooling tube bundle shown in FIG. 2;

FIG. 4 is a sectional view schematically showing a second embodiment of the condenser according to the present invention.

FIG. 5 is a longitudinal sectional view showing a main part of the second embodiment.

FIG. 6 is a sectional view schematically showing a third embodiment of the condenser according to the present invention.

FIG. 7 is a sectional view schematically showing a conventional condenser.

[Explanation of symbols]

 2 Steam cooling tube bundle 2A Upper steam cooling tube bundle 2B Lower steam cooling tube bundle 3 Enclosure plate 4 Air cooling tube bundle 5 Hot well 7 Drain reservoir 8 Drain discharge tube

Claims (4)

[Claims] 1. A steam cooling pipe bundle comprising a number of steam cooling cooling pipes extending in parallel with each other and in a substantially horizontal direction, and a space formed in a vertically central portion of the steam cooling pipe bundle. A surrounding shroud plate, and an air cooling tube bundle including a number of air cooling cooling tubes arranged inside the shroud plate and extending in parallel with each other and along the extending direction of the steam cooling tube bundle. A condenser disposed below the steam cooling tube bundle and comprising a hot well for collecting drain condensed and liquefied by the steam cooling tube bundle and the air cooling tube bundle, provided at a lower portion of the space. A drain reservoir extending along the extending direction of the air cooling tube bundle and storing the drain condensed and liquefied by the air cooling tube bundle; an upper end communicating with the drain reservoir and a lower end being a lower end of the steam cooling tube bundle; A drain discharge pipe that penetrates a lower portion of the steam cooling pipe bundle so as to be located below the drain and discharges the drain of the drain reservoir to the hot well without contacting the steam cooling pipe bundle. Condenser featured. 2. The system according to claim 1, wherein a lower end of said drain discharge pipe is located in a drain in said hot well.
The condenser according to. 3. The drain discharge pipe according to claim 1, wherein a portion extending downward from a lower end of the steam cooling pipe bundle is bent upward substantially in a U-shape on the way. Condenser. 4. A vertical direction which is provided at predetermined intervals along an extending direction of the bundle of steam cooling tubes, supports the bundle of steam cooling tubes and the bundle of air cooling tubes, and vertically separates the drain reservoir. A plurality of cooling pipe support plates extending to the drain pipe, and a drain communication hole formed in at least one of the plurality of cooling pipe support plates so as to communicate the divided drain reservoir. The condenser according to claim 1.