JPS599492A - Condenser - Google Patents

Abstract

PURPOSE:To deal with turbine bypass steam effectively by a method wherein a plenty of turbine bypass steam is distributed uniformly. CONSTITUTION:The introducing tubes 5 of the turbine bypass steam 3 are branched into two tubes corresponding to two groups of cooling tubes 13 and are arranged along the whole length of the lengthwise direction of the upper cylinder 10 above the groups of the cooling tubes 13. The turbine bypass steam 3 is injected and diffused into the condenser from the introducing tubes 5 as injected steam flows 4, 4'. The injected steam flows 4, 4', from two introducing tubes 5 collide at the center of the condenser and are condensed by the groups of cooling tubes 13 after passing through the central flow path 18 of the condenser. A steam dealing amount per unit length of the introducing tube may be reduced, a distance between an impact plate 16 and the introducing tube 5 may be shortened and increase of a height may be prevented by a method wherein the introducing tubes are arranged along the whole length of the lengthwise direction of the condenser. The steam dealing amount per unit length is small, therefore, the width of an opening for the impact plate 16 may be narrowed, the width of spread of the injected steam flows 4, 4' is also narrowed, an affection against the structure in the upper cylinder may be reduced and thereby, a highly reliable structure may be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface contact condenser for condensing the exhaust gas of a steam turbine in a steam turbine power plant, and in particular,
This invention relates to a condenser that achieves uniform distribution of turbine bypass steam.

The structure of a conventional condenser is shown in FIGS. 1(a) and 1(b). Exhaust gas 1 from the turbine passes through the upper shell 10 of the condenser, enters the lower shell 11, and enters the cooling pipes 7 forming a cooling pipe group 13 communicating with the water chamber 8. It exchanges heat with the flowing cooling water 2, condenses and becomes condensate, has a water level in the hot well 9 of the lower shell 11, and is discharged from the condensate outlet 12 again as boiler feed water. On the other hand, a relatively small amount of turbine bypass steam 3 from the boiler startup system passes through the introduction pipe 5 at the time of plant startup.
The injected steam stream 4 is introduced into the upper shell 10, exchanges heat with the cooling water 2, and condenses. As shown in FIGS. 2(a) and 2(b), the structure of this bypass steam introduction section consists of a large number of orifice holes 6 provided on the upper and lower surfaces of the introduction pipe 5, and an impact plate 16 installed opposite to the orifice holes 6. , has a structure for processing the turbine bypass steam 3. On the other hand, in recent years, due to variable pressure operation, adoption of coal-fired boilers, and application of special motion,
There is a tendency for the amount of turbine bypass steam introduced into the condenser to increase significantly, and the amount of turbine bypass steam introduced into the condenser is about 2
In some cases, it can be more than double. Therefore, a major challenge for condensers has been how to effectively process the large amount of turbine bypass steam that is not introduced during normal operation.

A large amount of turbine bypass steam is introduced at the same introduction position as in the past, as shown in Fig. 1 (a), Φ) and Fig. 2 (a), (b).

Even if we tried to solve the problem with the structure, it would not be possible to distribute the steam uniformly throughout the condenser, leading to a plant trip due to a local pressure rise inside the condenser, or damaging the adjacent low-pressure heater and bleed pipe, forcing the plant to shut down completely. Therefore, it may be necessary to consider other implementation methods.

Since only the uniform distribution of steam σ) throughout the condenser is considered,
For example, as shown in FIGS. 3(a) and 3(b), the upper body 10
Although it would be possible to avoid arranging a large number of inlet pipes 5, it not only complicates the system but also obstructs the flow path of the turbine exhaust 1.
This is not practical because it causes performance deterioration during normal operation and prevents the condenser from effectively condensing the turbine exhaust gas, which is the original purpose of the condenser. Further, the condenser is surrounded almost all around by the column base of the turbine mount, and there is no room for installing a large number of introduction pipes 5.

The next best solution to all the above-mentioned turbine exhaust obstructions and layout problems is to install turbine bypass steam at the bottom of the cooling pipe group 13 and at the top of the hot well 9, as shown in FIGS. 4(a) and 4(b). There is a method of connecting the main pipe 17 of the piping and arranging the introduction pipe 5 so that steam can be uniformly distributed inside the condenser, and this method is adopted in plants that process a large amount of turbine bypass steam.

However, this introduction method requires that the height of the lower body 1 is approximately three times the diameter of the introduction pipe 5, and that a cooling pipe protection plate 16 is required to prevent damage to the cooling pipe group 13. In addition, there are economic disadvantages such as the necessity of taking measures to completely prevent undulation of the real well caused by the jetted steam flow 4, leading to an increase in equipment costs. In addition, the basic structure such as the arrangement of the cooling pipe group 13 is as follows.
Since the plan is for steam to originally flow from the top to the bottom, the steam flow flowing from the bottom to the top will lead to performance deterioration and the potential for trouble.This introduction method is the basis of condenser planning. It doesn't suit me.

An object of the present invention is to provide a condenser that can effectively treat turbine bypass steam by uniformly distributing a large amount of turbine bypass steam.

Examples of the present invention will be described below with reference to FIGS. 5(a) and 5(b). The introduction pipe 5 for the turbine bypass steam 3 branches into two pipes corresponding to the two cooling pipe groups 13, and is disposed over the entire length in the longitudinal direction of the upper part of the cooling pipe group 13 of the upper body 10.

Turbine bypass steam 3 is injected from an inlet pipe 5 into a steam flow 4.
4' and is injected and diffused into the condenser. The injected steam stream 4 from the two inlet pipes 5 is impacted at the center of the condenser, passes through the central channel 18 and condenses in the cooling pipe group 13 . Since the injected steam flow 4' toward the outer wall of the condenser does not directly impinge on the cooling tube group 13, there is no need for the cooling tube protection plate 16 as shown in FIGS. 4(a) and 4(b). By arranging the introduction pipe 5 over the entire length of the condenser in the longitudinal direction, the amount of steam to be processed per unit length of the introduction pipe 50 is smaller than in the conventional structure.
It becomes possible to narrow the distance between the inlet tube 5 and the introduction tube 5, and it is possible to prevent an increase in height, which is a drawback when using the conventional structure. Furthermore, since the amount of steam to be processed per unit length is small, the width of the opening of the impact plate 16 can be narrowed, and the width of the jetted steam flow 4.4' can also be narrowed. It is possible to reduce the shadow # on the image, resulting in a highly reliable structure. Furthermore, the introduction pipe 5 is connected to the cooling pipe group 5.
3 is installed on top of turbine exhaust 1 during normal operation.
It does not become a major obstacle to the flow path, and is also advantageous in terms of improving performance (5). In addition, 14 in the figure is an air bleed pipe,
15 is a low pressure heater.

According to the present invention, a large amount of turbine steam can be reliably introduced into the condenser without affecting the performance of the condenser.

According to the present invention, for example, a large amount of turbine bypass steam can be uniformly diffused and distributed in the condenser, so that a highly reliable condenser can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1(a) is a longitudinal sectional view of a condenser with a conventional structure. (b) is a lateral sectional view, FIG. 2(a) is a perspective view of the introduction part of the turbine bypass steam, (b) is a lateral sectional view, and FIGS. 3(a) and 4) show a large amount of Longitudinal cross-sectional view of a condenser of conventional construction introducing turbine bypass steam of
3(b) and 4(b) are lateral sectional views thereof, FIG. 5(a) is a longitudinal sectional view of a condenser showing an embodiment of the present invention, and (b) is a sectional view thereof. FIG. 5...Introduction pipe, 10...Upper body, 13...Cooling pipe group, 15...Low pressure heater. Cb of eye 1) /4 eye 20 (kyu) (b) 30th and 71Z) / (b) 4th mouth (0L) (b)

Claims (1)

[Claims] 1. In a surface contact type condenser that brings turbine bypass steam into contact with a group of cooling tubes, the amount of the turbine bypass steam is increased over the entire length in the longitudinal direction of the upper part of the group of cooling tubes, corresponding to the number of the groups of cooling tubes. A condenser characterized by having an introduction pipe installed.