JPS6327636B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a condenser, and more particularly to an arrangement of cooling pipe groups in an air cooling section of a steam turbine condenser.

Steam turbine condensers are usually provided with a so-called air cooling section. The reason for installing this air cooling section is as follows. There is a negative pressure state from the low pressure stage of the steam turbine to the inside of the condenser, and air inflow from the communicating steam pipe flanges between the two is unavoidable. This mixed air is accumulated in the condenser together with ammonia gas and other gas generated when hydrazine, which is injected into the water supply of the high-pressure feedwater heater to prevent corrosion of steel pipes, is decomposed in the boiler. These non-condensable gases are extracted outside the vessel by an air extractor to maintain a predetermined degree of condensate vacuum.

Generally, these non-condensable gases are accompanied by steam, and an air cooling section is provided in order to recondense the entrained steam, reduce the gas volume, and reduce the load on the air extractor.

FIGS. 1 to 3 show examples of the arrangement of conventional condensers and air cooling units. Here, the turbine steam 14 is supplied to a cooling chamber 1 in which a tube nest 6, which is a collection of cooling pipes 1, is arranged.
5 from the surroundings, most of the steam is condensed by the cooling water flowing through the condenser cooling pipe 1 and condensed. Further, mixed air, ammonia gas, and some steam flow into the non-condensable gas bleed pipe 3 through the holes 10 and are guided to the air cooling section 7. Here, a part of the vapor is condensed and the non-condensable gases are further cooled and discharged through the air extraction pipe 8 by the air extractor 9. This air cooling section 7 is surrounded by a partition plate 5 on its top and side surfaces to prevent uncondensed steam from the surrounding tube nest 6 from flowing into the air cooling section 7, and to prevent uncondensed steam from flowing into the tube nest 6 between the support plates 2 holding the cooling tube 1. In the nest 6, a partition plate 11 shown in FIG. 2 is provided to prevent uncondensed steam from directly flowing into the uncondensed gas bleed pipe 3. 4
is a tube plate, 12 and 13 are water chambers, 16 is a casing,
17 is the central cavity of the tube nest, and 18 is condensate. This method of arranging the air cooling section has the following drawbacks.

(a) Extra space is required to provide the partition plates 5 and 11 within the tube nest, and there are also manufacturing difficulties.

(b) Part of the tube nest is partitioned with a partition plate, which causes uneven steam flow, which promotes uneven steam velocity and increases pressure loss.

An object of the present invention is to provide a condenser with excellent performance that solves the above-mentioned drawbacks.

An embodiment of the condenser according to the present invention will be described below with reference to the attached FIGS. 4 and 5.

In Figures 4 and 5 (-arrow view in Figure 4), the condenser consists of a cooling chamber 15 and water chambers 12 and 13. A tube nest 6 that is dense and loose at the periphery is held by the tube plate 4 and the tube support plate 2, and the turbine exhaust steam 14 led to the cooling chamber 15 is guided to the center of the tube nest 6. A non-condensable gas bleed pipe 3 having a hole 10 on its outer surface is installed in the central part 17 of the pipe nest. A cooling pipe 21 is housed inside the non-condensable gas bleed pipe 3 and is held by a semicircular baffle plate 22 .
As shown in FIG. 4, the baffle plates 22 are arranged so that the openings are arranged vertically (or horizontally) alternately. Non-condensable gases such as air and ammonia gas in the cooling chamber 15 and some steam that has not been condensed in the tube nest 6 are guided into the non-condensable gas bleed pipe 3 through the holes 10, and between the built-in cooling pipes 21. It flows in the longitudinal direction of the pipe while meandering. At this time, the uncondensed vapor is condensed, and the uncondensed gas is cooled and discharged through the air extraction pipe 8 in the air extractor 9.

As explained above, according to the present invention, the cooling pipe 2
1 is built in the non-condensable gas bleed pipe 3. Therefore, a partition plate 5 that partitions the air cooling section 7 and the pipe nest 6 is provided in a part of the pipe nest 6. The partition plate 11 to prevent blow-through is no longer necessary,
The flow of steam is improved, and wasted space can be saved.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing the structure of a conventional condenser.
2 is a sectional view in the - direction of FIG. 1, FIG. 3 is a sectional view in the - direction of FIG. 1, FIG. 4 is a sectional view of the condenser according to the present invention, and FIG. 5 is a sectional view in the - direction of FIG. FIG. 6: tube nest, 21: cooling pipe, 22: deflection plate,
3: Non-condensable gas extraction tube.

Claims (1)

[Claims] 1. In a condenser equipped with a non-condensable gas bleed pipe in a group of cooling pipes, the cooling pipe is arranged along the pipe axis in the bleed pipe, and non-condensed steam deflectors are arranged in a staggered manner perpendicularly to the cooling pipe. A condenser characterized by the following: