JPS6373004A - Steam turbine plant - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a steam turbine plant, and in particular, improves the arrangement of a plurality of feedwater heaters and improves the drain system of the feedwater heaters. 131 for steam coupin plant suitable for rationalization
do.

(Prior Art) Generally, as shown in FIG. Leads to 6. These low pressure feed water heaters), +Il Netsusa 5 are sequentially connected to the first low pressure feed water heater 5A, the second low pressure feed water heater 5B, the third low pressure feed water heater 5C, and the fourth low pressure feed water heater from the side of the condensate pump 3. It is a vessel 5D. 1) Water is extracted air from the steam turbine,
and the drain from the low-pressure feed water heater 5 disposed on the downstream side).

The above first to fourth low-pressure feed water heating:':j 5 A to D are
1. Shown in Figure 7 on the top of the main body of the water dispenser. 7' J: Placed in the sea urchin. The first and second low-pressure feed water heaters 5Δ, B are arranged side by side in a substantially horizontal plane vertically upward. Also, the third
The fourth low-pressure water heaters 5C and 5D are arranged vertically downward in a substantially horizontal plane.

Here, the internal pressure of the first low-pressure feed water heater 5A is the lowest, followed by the ff12 low-pressure feed water heater 5B, the third low-pressure feed water heater 2) 5C, and the fourth low-pressure feed water heater 5D is the lowest. expensive. Therefore, the drain from the fourth low-pressure feed water heater 5D is guided to the third low-pressure feed water heater 5C via the drain pipe due to the internal pressure difference.

Moreover, the drain of the third low-pressure feed water heater 5C is also guided to the second low-pressure feed water heater 5B via the drain pipe due to the pressure difference within the vessel.

However, since the internal pressure difference between the first low-pressure feed water heater 5Δ and the second low-pressure feed water heater 5B is small (for example, about 0.5 Kq/cd in the plant rated operating state), these first
J3 and second low pressure feed water heater 5A.

5B are simply connected by drain piping, the drain from the second low pressure water heater 5B cannot be recovered by the first low pressure water heater 5A.

Therefore, it is also possible to discharge the drain from the second low-pressure feed water heater 5B directly to the condenser 1 without guiding it to the first low-pressure feed water heater 5A. However, in this case, the second low pressure feed water heating! From 5B? :I temperature drain was not utilized effectively,
This will reduce the thermal efficiency of the plant. For example, 1
According to a trial calculation for a 100 MW class nuclear power plant, this corresponds to a relative reduction in output of about 2%.

Therefore, as shown in FIGS. 4 and 5, a new drain tank 7 was installed, and the drain cooler 9 of the first low-pressure feed water heater 5A was installed separately from the first low-pressure feed water heater 5△. is proposed. J3, the same parts in FIGS. 4 and 5 as in FIGS. 6 and 7 are not given the same reference numerals. In this case, the drain tank 7 is the first to fourth low pressure water heaters 5.
It is installed vertically below A to D. In addition, there is a drain cooling unit further below this drain tank 7! ! i9
will be installed.

The drain tank 7 guides and flashes (evaporates) the drain from the second low-pressure feed water heater 5B, and then cools the drain fJ.
Lead to I device 9. Since this drain tank 7 is reversely connected to the drain cooler 9 through the balance pipe 11, the drain from the second low-pressure feed water heater 5B is flushed in the drain tank 7 and drained into the drain cooler fJl device 9. It becomes almost equal to the temperature. The drain in the drain cooling 7Jl device 9 exchanges heat with the condensate to heat the condensate, and then is led to the condenser 1.

However, the drain tank 7 and drain cooler 741 container 9
Condensate 2) 1 Since it is installed in a place other than the upper part of the main body,
Installation space is required for this purpose. Moreover, the drain piping for connecting these devices 7.9 to each of the low-pressure feed water heaters 5A to D also becomes long.

Therefore, there is a drawback that the drain system of the low-pressure feed water heater becomes complicated.

Furthermore, the drain system of the low-pressure feed water heater becomes complicated and the installation space thereof increases, so the scale of the steam turbine building also becomes large.

(Problems to be Solved by the Invention) As mentioned above, in conventional steam turbine plants, there are problems such as a decrease in thermal efficiency, a complicated drain system for the low-pressure feed water heating tank, and an increase in the size of the turbine building. There is a problem.

This invention was made in consideration of the above facts,
It is an object of the present invention to provide a steam turbine plant that can rationalize a drain system of a feed water heater and contribute to downsizing of a steam turbine building.

[Structure of the invention]

(Means for Solving the Problems) This invention includes a plurality of feed water heaters having different internal pressures inside a condenser, and the condensate of the condenser is sequentially heated by the plurality of feed water heaters. At the same time as heating, the drains in the plurality of feedwater heaters are: H; The heater is placed vertically below the feed water heater, which has the next lowest internal pressure.

(Function) Therefore, the steam turbine blunt according to the present invention,
A hydrostatic head difference is secured between the feed water heater with the lowest internal pressure and the feed water heater with the next lowest internal pressure, and the drain in the feed water heater with the next lowest internal pressure is Easily the lowest feed water heater to four.

(Example) Hereinafter, an actual example of the present invention will be explained based on the drawings.

FIG. 1(A) is a partially cutaway side view showing a low-pressure natural air turbine, a condenser, and a low-pressure feed water heater in an embodiment of a steam turbine plant according to the present invention. 1st
Figure (B) is a view taken along the IB arrow in Figure 1 (A). FIG. 3 is a system diagram showing the condensate system of this embodiment.

For example, in a nuclear power plant, Fig. 1 (A).

As shown in (B), a condenser 23 is installed below the low pressure steam turbine 21. External casing 2 of condenser 21
5J3 and the condenser main body +6127 of the condenser 23 are housed in the turbine building 26. In addition, external casing 2
5 and the condenser main body shell 27, an expansion 29 is interposed between the condenser body shell 27 and the difference in thermal deformation between the two members 25.degree. 27.

A large number of condenser heat transfer tubes 333 connected to the condenser water chamber 31 are disposed in the lower part of the condenser main body shell 27 . Seawater flows into the condenser heat transfer tube 33 via the condenser water chamber 31. The steam that has done work in the low-pressure natural air turbine 21 is cooled by the condenser heat exchanger tube, and is accumulated in the lower part of the condenser body +127. A condenser outlet pipe 3 is installed at the bottom of the condenser body shell 27.
5 is attached, and this condensate; S outlet pipe 35 is connected to the condensate pipe 37 of the water system (not shown in FIG. 3).

The condensate pump 3 is installed in the condensate pipe 37 sequentially from the side of the condenser 23.
9, a'T1 A low pressure feed water heater 41A, a second low pressure feed water heater 41B, a third low pressure feed water heater 41G, a fourth low pressure feed water heater 41D, and a water feed pump 43 are provided. The condensate pump 39 pumps condensate from the condenser 23 to the first to fourth low-pressure feed water heaters 41A-D. Also,
The feed water pump 43 receives (from the fourth low pressure feed water heater 41D)
(Water is supplied as water and guided to a high-pressure feedwater heater, a nuclear reactor, etc. (not shown). Roughly speaking, the first to fourth low-pressure feedwater heaters 41Δ to D sequentially heat condensate.

The first to fourth low pressure water heaters 41A to 41D are shown in FIG. 1(A).
, is disposed at the upper part of the condenser main body shell 27 as shown in (B). As shown in an enlarged view in FIG. 2, the first low-pressure feed water heater 41A, which has the lowest internal pressure, is located at a lower position in the vertical direction.
The second low-pressure feed water heaters 41B, which have the next lowest internal pressure, are installed at positions in the trunk direction. Further, the fourth low pressure feed water heater 410 having the highest internal pressure is the second low pressure feed water heater 4.
Directly below 1B, there is a third low-pressure feed water heating f that is the next highest after the internal pressure.
i410 are respectively installed directly above the first low pressure feed water heating B41A. Therefore, the first and fourth low pressure feed water heaters 7 & 41Δ, D and the second J3 and third low pressure feed water heaters 4
A vertical position difference Hffi is set between 1B and 1C. This difference of 1-1 is the hydrostatic head difference.

For example, in a 1100 MW class nuclear power plant, the internal pressure of the fourth low-pressure feed water heater 41D is 9 parts cm, and the third low-pressure feed water heater Z41C is approximately 2°9 kg /
ci, the second low pressure water heater 41B is about 1. OR3/
ci, the first low pressure water supply heating m41A is approximately 0.59/c
d, and the position difference 1'' is approximately 2.5 m.

By the way, each of the low-pressure feed water heaters 41A to 41D is disposed at the upper part of the feed water heater main body so that no condensate flows through the feed water heater heat transfer tube and the feed water heater main body +! , a drain cooling part provided at the lower part of i, and a flash part adjacent to the drain cooling part at the lower part of the feed water heater main body 134, and near the connection part of the drain pipes 45D, C, and B of (rear) e. It is composed of:

The drain cooling part of the fourth low-pressure feedwater heating pipe 41D is connected to the feedwater heater main body 1) 1 of the third low-pressure feedwater heater 41C via a fourth drain pipe 45D. Third low pressure water heater 4
A portion of the 1G drain is cooled by contacting the feedwater heater main body 1 of the second low-pressure feedwater heater 41B via the third drain pipe 45G. The drain cooling IJI portion of the second low pressure feed water heater/11B is connected to the feed water heater main body barrel of the first low pressure feed water heater 41Δ via the third drain pipe 45B.

Fourth and third low-pressure feed water heaters 41D, C (based on Qm internal pressure J4, drain in the fourth low-pressure feed water heater/11D is recovered to the third low-pressure feed water heater 41G via the fourth drain pipe 45D) Similarly, based on the internal pressure difference between the third and fourth low-pressure feedwater heaters 41C and 3, the drain in the third low-pressure feedwater heater/IIC is drained to the second through the third drain pipe 45G. The internal pressure of the second and first low pressure feed water heaters 41B and Δ) is recovered to the low pressure feed water heater 41B.
] Based on the difference and the positional difference (static head difference) 1-1 between the second and first low-pressure feed water heaters 41B and A, the second drain pipe 4
5B, the drain in the second low pressure feed water heater 41B is recovered to the first low pressure feed water heater 41A.

The aforementioned third, second J3 and first low pressure water heater 41C
, B, are the fourth, third, and second flash sections, respectively.
This is to flash (evaporate) the drain led from the drain pipes 45D, C, and B.

After passing through this flash section, the condensate flows down the outside of the feed water heat exchanger tube. Furthermore, oil from the steam turbine flows into the feedwater heater main body 4, and is guided to the outside of the feedwater heater heat exchanger tube. Therefore, these bleed air and condensate directed from the low pressure feedwater heater heat the condensate flowing through the feedwater heater heat exchanger tubes.

The drain cooling section of the first feed water heater 41Δ is connected to the condenser flash box 47 of the condenser 23 via the first drain pipe 45A. This condenser flash box 47 is shown in FIG. 1 (△).

As shown in (B), the drain flash (evaporation) from the drain cooler of the first low-pressure feed water heater 41△ is disposed outside the lower part of the condenser main body 27, and the condenser main body body 27
Lead to the bottom of.

Note that notification numbers 49B, 49G, and 49D in Figure 2 are drain water level control valves, respectively, which control the drain water levels of the second low-pressure feed water heater 41B, the third low-pressure feed water heater 41C, and the fourth low-pressure feed water heater 41D, respectively. While doing so, drain the drain 1°.

Therefore, according to the above embodiment, the second low pressure Since the drain in the drain cooling section of the feed water heater 41B was led to the feed water heater main body barrel of the first low pressure feed water heater 41A, a conventional J, sea urchin drain tank 7 (Figs. 5 and 6) was installed, There is no need to separately install the drain cooling IJl device 9 (FIGS. 5 and 6). Therefore, the drain system of the low-pressure feed water heater can be simplified and its rationalization can be achieved. The effect is particularly remarkable in the improved boiling water reactor (-ABWR).

Furthermore, since the drain system of the low-pressure feedwater heater can be simplified, the equipment installation space and piping space can be reduced, and the steam turbine building can be downsized.

In addition, the diameter of the feed water heater main body I (is the largest in the first low pressure feed water heater, and is formed smaller in the order of the second, third, and fourth low pressure feed water heaters. Therefore, the second low pressure feed water heater 41 [3
is not directly above the first low-pressure feed water heater 41A, but on the side vertically adjacent to the first low-pressure feed water heater 41A, that is, the second
In the figure, since they are installed obliquely above the first low-pressure feed water heater 41Δ, the installation space for the low-pressure feed water heaters 2i41A-D can be reduced. As a result, condenser 2
No. 3 height is increased, and the building space is also not increased.

In the above actual flow example, the third low-pressure feedwater heater 41G is installed directly above the first low-pressure feedwater heater 41A, and the fourth low-pressure feedwater heater i541D is installed directly below the second low-pressure feedwater heater 41[3]. However, the positions of the third and fourth low-pressure water heaters 41C and 41D may be reversed.

Furthermore, the second low pressure water heater 41B may be installed directly above the first low pressure water heater 41Δ. In this case, although the building space is slightly increased compared to the previous embodiment, the drain system of the low pressure feed water heater can be rationalized, and the bad air turbine building can be downsized compared to the conventional example.

(Effects of the Invention) As described above, according to the steam turbine plant according to the present invention, for heating the feed water with the lowest internal pressure; As a result, a hydrostatic head difference can be secured between both feedwater heaters, and the drain in the feedwater heater, which has the second lowest internal pressure after the internal pressure, can be easily guided to the feedwater heater with the lowest internal pressure. Can be done. As a result, it is possible to rationalize the drain system of the feed water heater, and it is possible to contribute to downsizing of the turbine building.

[Brief explanation of the drawing]

FIG. 1 (△) is a partially cutaway side view showing a low-pressure steam turbine, condenser J3, and low-pressure feed water heater in an embodiment of a steam turbine plant according to the present invention; FIG.
) is a view taken in the direction of the IB arrow in FIG. 1 (A), FIG.
Figure 4 is a system diagram showing the condensate system of this embodiment, Figure 4 is a system diagram showing the condensate system in a conventional steam turbine plant, and Figure 5 is a system diagram showing the drain system of the low-pressure feed water heater in Figure 4. Figure 6 shows the conventional steam turbine plant
Figure 7 is a system diagram showing the condensate system of '31. Figure 7 is a layout diagram of the low pressure feed water heater of Figure 6. 21...Low pressure steam turbine, 23...Condenser, 41
A... 1st low pressure water heater, 41 [3... 2nd low I
[Feed water heater, 45B...Second drain pipe, H...
Difference in position between the first J3 and the second low pressure feed water heater. Applicant's agent Hisashi Hatano Figure 3 Figure 4 Figure 5 Procedure 7111 Masako (spontaneous) October 1985 - L3 Commissioner of the Patent Office Kuro 1) Akio Tono 1, Indication of the case 1989] 61 Patent FF11217700 No. 2, Name of the invention Steam turbine plant 3, Relationship with the amended case Patent applicant (307) Toshiba Corporation 4, Agent Address: 3-4-1 Nishi-Shinbashi, Minato-ku, Tokyo 105 5. Drawings subject to amendment 6. Details of amendment Figure 1 (B) will be corrected as shown in the attached drawing.

Claims (1)

[Claims] 1. A plurality of feed water heaters having different internal pressures are provided inside the condenser, and the condensate of the condenser is sequentially heated by the plurality of feed water heaters, and the In a steam turbine plant configured to sequentially guide condensate in multiple feedwater heaters from a feedwater heater with a high internal pressure to a feedwater heater with a low internal pressure, the feedwater heater with the lowest internal pressure is placed next to the internal pressure. A steam turbine plant characterized in that the plant is located vertically below a low feedwater heater. 2. The steam turbine plant according to claim 1, wherein the feedwater heater with the lowest internal pressure is installed on a side vertically adjacent to the feedwater heater with the next lowest internal pressure.