JPS5853162B2 - Grand steam desuperheater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gland steam attemperation device, and more particularly to a steam attemperation device for supplying gland steam to a low-temperature section of a steam turbine.

In the grand steam system diagram in Figure 1, high pressure turbine 1
, the gland parts 5 and 6 of the intermediate pressure turbine 2 tend to leak steam from the turbine, and the pressure of this is adjusted by the steam pressure regulator 8 and is supplied to the gland part 7 of the low pressure turbine 3 via the piping 12. ing.

Low-pressure turbine gland 7 → If the steam is insufficient due to high- and intermediate-pressure turbine steam leakage steam, supply steam to the main steam pipe 14.
From there, it is led to the steam pressure regulator 8 through a pipe 15 for use, and if there is any surplus, it is disposed of through a pipe 16 to the condenser 4 or the like.

For this reason, the steam supplied to the steam pressure regulator 8 as sealing steam for the low-pressure turbine is sufficiently high-temperature, and the steam that is supplied to the steam pressure regulator 8 as seal steam for the low-pressure turbine has a sufficiently high temperature. This is not good for the rotor.

As a method for lowering the steam temperature at the low-pressure turbine seal, there are methods such as cooling the conduit in the main stream of the turbine exhaust before the steam is supplied to the low-pressure turbine gland.
■A method is adopted in which a gland steam desuperheater is installed and cooling is performed using condensate.

FIG. 2 shows a method for cooling low pressure turbine gland seal steam with the turbine exhaust stream.

FIG. 3 is a view seen in the direction of the arrow ``■'' in FIG. 2.

To enhance the cooling effect, the conduit 13 forms a loop pipe 19 at a position facing the main exhaust stream 18 from the low-pressure turbine 30 rotor blades 17 .

The gland seal steam cooled by the exhaust main flow 18 is guided to the low pressure turbine gland 7 through the pipe 13.

However, in this method, in order to increase the temperature reduction effect, the loop tube 1
9 is disposed at a position directly exposed to the main stream of turbine exhaust gas, there is a drawback that the smooth flow of the main stream of exhaust gas 18 is obstructed and efficiency is inevitably lowered.

FIG. 4 shows a method of cooling low pressure turbine seal steam using a separate attemperator.

A separate gland steam attemperator 20 is installed in the middle of the low pressure gland seal steam conduit 12 to cool the seal steam.

The cooling water is used by branching condensate from the condenser 4 from the outlet 22 of the condensate pump 21 and guiding it through a pipe 23.

Cooling water after use is returned to the condenser 4 through the pipe 24.

In this method, the desuperheater 20 is installed independently outside the condenser 4, and sufficient consideration is required in designing and manufacturing it as a single pressure vessel. The drawback is that it requires equipment and is quite large-scale.

SUMMARY OF THE INVENTION An object of the present invention is to provide a low-pressure turbine gland sealing steam temperature reduction device that does not reduce the efficiency of the turbine and has a simple structure.

The main point of the present invention is to dispose a desuperheater cooled by condensate inside the condenser at a position that does not disturb the main flow of turbine exhaust air, in order to detemperature the steam for sealing the low-pressure turbine gland. It is something.

Next, one embodiment of the present invention will be described.

In FIG. 5, the outline of the gland seal system is almost the same as that in FIG. 4, so to explain the differences, a desuperheater 26 is provided inside the enlarged upper body portion 25 of the condenser 4.

A low pressure gland seal steam conduit 1 is installed inside this desuperheater 26.
Pass 2.

The cooling water is used by branching the condensate from the condenser 4 from the outlet 22 of the condensate pump 21 and guiding it to the desuperheater 26 through the conduit 23, similar to the method shown in FIG.

The cooling water after use may be dripped into an appropriate position within the condenser 4 through the downcomer pipe 27.

As is clear from the above explanation, the upper body enlarged portion 2 of the condenser 4
Since the desuperheater 26 is provided inside the turbine 5, it is located at a position where the main stream 18 of the exhaust gas is difficult to sufficiently diffuse, and there is almost no possibility of a decrease in the efficiency of the turbine.

Furthermore, since the desuperheater 26 is installed inside the condenser 4, it does not need to have the characteristics of a pressure vessel, and may have an extremely simple structure.

To explain in more detail, in FIGS. 6 and 1,
The attemperator 26 is installed by welding the tubular side 28 constituting the attemperator 26 to the inside of the upper body enlarged portion 25 of the condenser 4 and reinforcing it.
It stops at 9.

A steam conduit 12 is passed through this tubular side 28.

Further, the tubular side 28 is filled with condensate 30 guided through the pipe 23, and the remaining condensate is dripped into the condenser 4 through the downcomer pipe 27.

In this case, it is not necessarily necessary to provide the downcomer pipe 27; for example, if a hole of an appropriate size is made in the position 31 of the body pipe 28, the remaining condensate will flow through the condenser wall 32 and reach the condenser 40.
Since it descends without scattering downward, it does not damage the tubes (not shown) in the condenser.

As described above, the gland steam attemperator according to the present invention does not need to be a pressure vessel unlike the prior art, and can have an extremely simple structure.

As mentioned above, the desuperheater 26 of the present invention achieves the original purpose by making the structure extremely simple, but as shown in FIG. If the amount of cooling water supplied to the desuperheater 26 is adjusted by opening and closing the regulating valve 34 on the piping 23 using the valve 37, even more accurate gland seal steam temperature management can be achieved.

Next, other embodiments of the present invention will be described.

As shown in FIG. 8 (for reasons such as simplification of arrangement, the feed water heater 35 may be incorporated into the body of the condenser 4 and the bleed pipe 36 may be shortened).

Of course, the feed water heater 35 in this case is the main stream 1 of the exhaust gas of the turbine.
I chose a position where 8 is not holed as much as possible.

In such a case, if a gland steam attemperator 26 having the structure shown in FIGS. 6 and 7 is provided in contact with the lower side of the feed water heater 35 as shown in the figure, the gland steam attemperator 2
6 is installed in the condenser 4, it does not disturb the turbine exhaust main stream 18, and there is no need to worry about the effect of lowering the efficiency of the turbine.

In FIG. 8, a gland desuperheater 26 is placed below the feed water heater 35.
Of course, it is also possible to install it on the upper side.
The point is that it should be installed at a location within the condenser 4 that does not disturb the main stream 18 of the turbine exhaust gas.

According to the present invention, it is possible to realize a temperature reduction device that has a simple structure and reduces the temperature of low-pressure turbine gland seal steam without reducing turbine efficiency.

[Brief explanation of the drawing]

Figure 1 is a system diagram of gland steam, Figure 2 is a schematic diagram showing the conventional low-pressure gland seal steam detemperature method, Figure 3 is a view taken in the direction of the ■ arrow in Figure 2, and Figure 4 is also a diagram of the conventional technology. A schematic diagram showing a low-pressure gland seal steam detemperature method, FIG. 5 is a schematic diagram showing a low-pressure gland seal steam detemperature device according to an embodiment of the present invention, and FIG. 6 is an enlarged view of the ■ part in FIG. FIG. 7 is a view taken in the direction of the {circle around (1)} direction in FIG. 6, and FIG. 8 is a schematic diagram showing a low-pressure gland seal steam temperature reduction device according to another embodiment of the present invention. 4...Condenser, 7...Gland part, 8...Steam pressure regulator, 12.13...Gland steam pipe, 23...
- Condensate conduit, 25... Upper shell enlarged part, 26... Grand steam desuperheater, 27... Downpipe, temperature meter, 34... Control valve, 3. Control device. 28...Tubular, 33...Temperature 5...Water heater, 37...

Claims (1)

[Scope of Claims] 1. A gland steam desuperheater for reducing the temperature of steam led through a steam pressure regulator as supply steam for the gland seal of the low-pressure turbine is installed on the inner wall of the enlarged upper body of the condenser. 1. A gland steam detemperature device comprising a tubular shell, a gland steam conduit passing through the tubular shell, and piping for introducing condensate into the tubular shell. 2. In a condenser with a feed water heater installed, a gland steam desuperheater that reduces the temperature of steam led through a steam pressure regulator as supply steam for the low-pressure turbine gland seal is installed in the condenser. A tubular shell disposed adjacent to the downstream side of the feed water heater with respect to the main stream of internal exhaust, a ground steam conduit passing through the tubular shell, and a pipe for introducing condensate into the tubular shell. Features a grand steam detemperature device.