JPS6119912B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface contact condenser for condensing exhaust gas from a steam turbine in a steam turbine power plant, and more particularly to a condenser for uniformly distributing turbine bypass steam.

The configuration of a conventional condenser is shown in Figures 1a and 1b. Exhaust gas 1 from the turbine passes through the upper shell 10 of the condenser and enters the lower shell 11, where cooling water 2 flows through cooling pipes 7 forming a cooling pipe group 13 communicating with the water chamber 8.
It exchanges heat with the lower shell 11, condenses and becomes condensate
The water level is maintained at the hot well 9, and the water is discharged from the condensate outlet 12 again as boiler supply 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.
It becomes a jet steam flow 4 and is introduced into the upper shell 10,
It exchanges heat with cooling water 2 and condenses. As shown in FIGS. 2a and 2b, 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 in response to the orifice holes 6. It has a structure that processes. On the other hand, in recent years, the amount of turbine bypass steam introduced into the condenser has tended to increase significantly due to variable pressure operation, the adoption of coal-fired boilers, and the application of special motion. 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.

Even if we try to deal with a large amount of turbine bypass steam using the same introduction position and structure as in the past, as shown in Figure 1 a, b and Figure 2 a, b, it is not possible to distribute the steam uniformly throughout the condenser. However, it is necessary to consider other introduction methods because this may cause a plant trip due to a local pressure increase in the vessel, or damage the adjacent low-pressure heater and air bleed pipe, forcing the plant to shut down.

If only the uniform distribution of steam throughout the condenser is considered, the upper shell 1
Although it is possible to install a large number of inlet pipes 5 in the condenser 0, it not only complicates the system, but also obstructs the flow path of the turbine exhaust 1, leading to a decrease in performance during normal operation, and preventing the original purpose of the condenser from being used. This is impractical as it would prevent effective condensation of some turbine exhaust. Also,
The condenser is surrounded almost all the way around by the column base of the turbine frame, and there is no room for installing a large number of introduction pipes 5.

The next best way to solve the above-mentioned turbine exhaust obstruction and arrangement problem is to install the main pipe 17 of the turbine bypass steam piping at the lower part of the cooling pipe group 13 and the upper part of the hot well 9, as shown in FIGS. 4a and 4b. There is a method of connecting the condenser and arranging the introduction pipe 5 so that the 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, with this introduction method, the height of the lower body 11 increases by about three times the diameter of the introduction pipe 5, and the cooling pipe group 13 increases.
There are economic disadvantages that increase equipment costs, such as the need for a cooling pipe protection plate 16 to prevent damage to the cooling pipe, and the need for measures to prevent the hot well from waving caused by the jetted steam flow 4. . Also,
The basic structure, such as the arrangement of the cooling pipe group 13, is originally planned so that steam flows from the top to the bottom, so the steam flow flowing from the bottom to the top will lead to performance deterioration and the potential for trouble. , this introduction method does not suit the basic planning of the condenser.

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.

Embodiments of the present invention will be described below with reference to FIGS. 5a and 5b. 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. The turbine bypass steam 3 is injected and diffused into the condenser through the introduction pipe 5 as jet steam flows 4, 4'. The injected steam particles 4 from the two inlet pipes 5 impact at the center of the condenser, pass through the central passage 18, and condense in the cooling pipe group 13. Since the jet steam flow 4' toward the outer wall of the condenser does not directly collide with the cooling pipe group 13, the cooling pipe protection plate 1 as shown in FIGS. 4a and 4b is used.
6 is not required. By arranging the introduction pipe 5 over the entire length of the condenser in the longitudinal direction, the amount of steam processed per unit length of the introduction pipe 5 is smaller than that of conventional structures, and the distance between the shock plate 16 and the introduction pipe 5 can be reduced. This allows the structure to be made narrower, thereby preventing an increase in height, which is a drawback when using a conventional structure. In addition, 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 spread width of the jetted steam flows 4, 4' is also narrowed, so that the structure in the upper shell 10 is The impact can be reduced, resulting in a highly reliable structure. Furthermore, the introduction pipe 5
Arranging the cooling pipe group 53 at the upper part of the cooling pipe group 53 does not cause a major obstruction to the flow path of the turbine exhaust gas 1 during normal operation, and is also advantageous in terms of performance improvement. In addition, in the figure, 14 is an air bleed pipe, and 15 is a low pressure heater.

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

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

[Brief explanation of the drawing]

Fig. 1a is a longitudinal sectional view of a condenser with a conventional structure, b is a lateral sectional view thereof, Fig. 2a is a perspective view of the turbine bypass steam introduction section, b is a lateral sectional view thereof, Fig. 3 Fig. 4a and Fig. 4a are longitudinal sectional views of a condenser with a conventional structure that introduces a large amount of turbine bypass steam, Fig. 3b and Fig. 4b are their transverse sectional views, and Fig. 5a is a main view of the condenser. FIG. 1 is a longitudinal sectional view of a condenser showing an embodiment of the invention, and b is a lateral sectional view thereof. 5...Introduction pipe, 10...Upper body, 13...Cooling pipe group, 15...Low pressure heater.

Claims (1)

[Claims] 1. In a surface contact type condenser that brings turbine bypass steam into contact with a group of cooling tubes, the turbine bypass steam is introduced 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 installing pipes.