JPH0316470B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a turbine building, and more particularly to a turbine building in which a moisture separator reheater is arranged.

[Background of the invention]

Conventionally, the structure of a moisture separation reheater was based on Nakagami and Manabe's Design and Operation of a Moisture Separation Heater (Re)heater for Nuclear Power Turbines (1983, Thermal and Nuclear Power Generation, No. 325).
Discussed in the literature entitled.

Here, we will briefly explain the system configuration of the reheat cycle of a PWR power plant based on the steam system based on Figure 8. (The equipment for condensing water is omitted.) In Fig. 8, 1 is a high-pressure turbine;
2 is a moisture separation reheater, 3A and 3B are main steam pipes, 4
indicates the extraction steam pipe. Saturated steam with a humidity of about 4% generated in the steam generator 5 is guided to the high pressure turbine 1 through the main steam pipe 3A. Steam with increased humidity discharged from the high pressure turbine 1 is transferred to the main steam pipe 3B.
The steam is supplied to the moisture separation reheater 2 by the bleed steam pipe 4, and after moisture is removed, it is heated by the bleed steam supplied by the bleed steam pipe 4. Steam discharged from the moisture separator reheater 2 is supplied to the low pressure turbine 6 through the main steam pipe 3B. Since the moisture separator reheater 2 has an integral structure of the moisture separator and the two-body heater, the body of the moisture separator reheater 2 has a large-capacity equipment configuration.

On the other hand, in pressurized water nuclear power plants (hereinafter referred to as PWR power plants) in Japan, the steam discharged from the high-pressure turbine is extracted from the main steam after removing moisture in order to reduce the humidity within the turbine cycle. The system employs a so-called reheat cycle method, in which the heated steam is heated to produce heated steam.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a turbine building that houses a steam system for a reheat cycle and can shorten the period for maintenance and inspection of a turbine.

[Summary of the invention]

Constituent features of the first invention of the present application include: a building having an operating floor; a condenser installed below the operating floor in the building; and a condenser disposed with at least an upper portion protruding above the operating floor surface; a low-pressure turbine located above the condenser to supply steam to the condenser; and a low-pressure turbine installed with at least an upper portion protruding above the operating floor surface, and a rotating shaft configured to rotate the low-pressure turbine. In a turbine building that includes as a main component a high-pressure turbine connected to a shaft, a pipe is connected to a pipe for guiding steam from the high-pressure turbine and passes the introduced steam through a moisture separating means and a heating means to other pipes. The turbine building is characterized in that a moisture separation reheater for passing the low-pressure turbine through the turbine is installed in the building below the operating floor. In addition to securing a wide laydown area, it is also possible to reduce the radiation exposure of maintenance and inspection workers, so it is possible to obtain the effect of significantly shortening the period for maintenance and inspection of turbines.

Constituent elements of the second invention of the present application include a building having an operating floor, a condenser installed in the building below the operating floor, and a condenser built in the condenser to collect condensate from the condenser. a low-pressure feedwater heater that heats the condensed cooling water; a plurality of high-pressure feedwater heaters that heat the condensed cooling water from the low-pressure feedwater heater and pass it through the reactor inner vessel; a low-pressure turbine installed with an upper part protruding and located above the condenser; and a low-pressure turbine installed with at least the upper part protruding above the operating floor surface, and a rotating shaft with a rotating shaft of the low-pressure turbine. In a nuclear power plant consisting of a turbine building that includes a connected high-pressure turbine as a main component and a reactor building that houses the reactor vessel, it is connected to piping that guides steam from the high-pressure turbine. A moisture separator reheater for passing steam through a moisture separator and a heating means and through another piping to the low pressure turbine is installed in the building below the operating floor, and the plurality of high pressure feed water heaters are installed in the building below the operating floor. The turbine building is characterized in that the turbine buildings are installed in positions closer to the reactor building than the moisture separator reheater in the turbine building below the operating floor surface, and are distributed vertically and horizontally. When a turbine building is installed, each feedwater heater is also installed under the operating floor, and it can be installed inside the condenser or by transferring cooling water from multiple high-pressure feedwater heaters to the reactor building side. Considering ease of use, multiple high-pressure feed water heaters were distributed vertically and horizontally along the wall of the turbine building from the reactor building to ensure space for installing the moisture separation reheater. Not only is this possible, but it can also have the same effects as the first invention.

In the turbine building of the aforementioned PWR power plant, the moisture separation reheater is installed above the operating floor. Assuming that the arrangement of the moisture separator reheater of such a PWR power plant is directly applied to the turbine building of a BWR power plant, the structure of the building will be described below with reference to FIGS. 9 to 11.

This turbine building consists of three turbines installed in building 7.
A base condenser 8, one high-pressure turbine 1 installed in the building 7, three low-pressure turbines 6, and the building 7
It has two moisture separation reheaters 2 installed on the operating floor 9, which is the top floor of the plant. Two moisture separator reheaters 2 are placed on both sides of the turbine with the turbine in between. High pressure turbine 1 and low pressure turbine 6
Since the steam containing radioactive materials generated in the nuclear reactor is guided inside, it is covered with a radiation shielding cover during the operation of the nuclear reactor. Since the moisture separator reheater 2 is also supplied with steam generated in the nuclear reactor, the moisture separator reheater 2 is surrounded by a thick concrete wall 10 that is a radiation shield. The moisture separator reheater 2 has a built-in heat exchanger for heating the steam discharged from the high-pressure turbine as well as a moisture separator, so it has a shell diameter (about 4 m) and a shell length (about 30 m). It will also happen. Therefore, the proportion of the moisture separation reheater 2 covered with the concrete wall 10 in the operating floor 9 increases.

During maintenance and inspection of the turbines and the like of a BWR power plant, the radiation shields covering the high-pressure and low-pressure turbines 1 and 6 and their casings need to be removed and placed side by side on the operating floor 9. Furthermore, it is necessary to remove the turbine rotor and other parts such as bearings from each turbine, place them on the operating floor 9, and perform maintenance and inspection on them on the operating floor 9. However, since the floor area of the operating floor 9 is occupied to some extent by the two moisture separation reheaters 2, the operating floor 9 is used to place the disassembled turbine rotors and other parts at the same time.
The upper space is no longer available, making it impossible to carry out these maintenance and inspection tasks at the same time. For this reason, the driving bed 9
After the maintenance and inspection of some of the parts has been completed, the parts must be returned to their original positions, and then the next part must be removed and moved onto the operating floor 9 for maintenance and inspection.
Therefore, the period for maintenance and inspection of the turbine becomes longer.

The present invention has been made based on the results of such studies.

[Embodiments of the invention]

Before explaining the structure of a turbine building which is a preferred embodiment of the present invention, it is necessary to explain the structure of a turbine building having a moisture separation reheater.
The structure of the BWR power plant will be explained based on FIGS. 5, 6, and 7.

The schematic system of the BWR plant will be explained based on Fig. 5. Steam generated in the reactor vessel 10 is sent to the high pressure turbine 11 via the main steam pipe 33. The temperature of the steam discharged from the high-pressure turbine 11 is slightly lowered by driving the high-pressure turbine 11, and the moisture content of the steam is increased. This steam is
The main steam pipe 34 is sent to the moisture separation reheater 13 where moisture is removed and heated.
5, and is supplied to a low pressure turbine 12 connected to the rotating shaft of a high pressure turbine 11. Steam discharged from the low pressure turbine 12 is condensed into water in the condenser 20. This water is returned to the reactor vessel 10 as cooling water through the water supply pipe 36, which has the following equipment. The cooling water discharged from the condenser 20 is pressurized by a first condensate pump 21, purified by a condensate filtration demineralizer 22 and a condensate demineralizer 23, and is pressurized by a second condensate pump 24. 1st stage low pressure feed water heater 25, 2nd stage low pressure feed water heater 2
6. Heated by the third stage low pressure feed water heater 27, the fourth stage low pressure feed water heater 28, and the fifth and sixth stage low pressure feed water heaters (not shown), and further increased in pressure by the water feed pump 29, After being heated by the first-stage high-pressure feedwater heater 30 and the second-stage high-pressure feedwater heater 31, it reaches the reactor vessel 10. Steam extracted from the low pressure turbine 12 (referred to as extracted steam) is passed through an extraction pipe 37.
- 40 are guided from the first-stage low-pressure feedwater heater 25 to the fourth-stage low-pressure feedwater heater 28 to heat the cooling water flowing in the water supply pipe 36. After that, the temperature of the bleed steam decreases and it becomes drain water from inside each low-pressure feed water heater to the drain pipe 4.
1, and then reaches the condenser 20 and is supplied into the water supply pipe 36. High-temperature, high-pressure bleed steam extracted from the high-pressure turbine 11 by the bleed pipes 42 and 43 is guided to each high-pressure feed water heater, and further heats the cooling water flowing in the water supply pipe 36. This extracted steam becomes high-temperature drain water and is guided into the tank 45 through the drain pipe 44. Further, the tank 45 is supplied with high-temperature drain water discharged from the moisture separator reheater 13 and collected in each drain tank described below through a drain pipe 46. The high temperature drain water collected in the tank 45 is pressurized by the pump 47 and then sent to the fourth stage low pressure water heater 28.
The water is guided into the water supply pipe 36 on the downstream side of the water.

FIG. 6 shows the detailed structure of the moisture separator reheater 13A. The moisture separator reheater 13A has a larger volume than a conventional moisture separator due to the presence of the reheater. Moisture separation reheater 13A is shell 1
4, and a first stage reheater 1 in the shell 14.
5A and 15B, second stage reheater 16A and 16B
and moisture separators 17A and 17B.
The shell 14 is elongated in the horizontal direction. The first stage reheater 15A, the second stage reheater 16A and the moisture separator 17A are arranged on the left side in the shell 14. 17B are arranged on the right side within the shell 14. Moreover, the moisture separator, the first stage reheater, and the second stage reheater are arranged in this order from the bottom to the top of the shell 16. The bottom of the shell 14 is provided with four steam inlets 18A-18D and four drain outlets 48A-48D. ciel 1
4 are provided with three steam outlets 19A to 19C.

The system configuration near the moisture separator reheater 13 in FIG. 5 will be explained based on FIG. 7.

Although one moisture separator reheater 13 is shown in FIG. 5, in reality two moisture separator reheaters 13A and 13B are provided in parallel as shown in FIG. . The moisture separator reheater 13B has the same structure as the moisture separator reheater 13A shown in FIG. The connection state between the moisture separator reheater 13 and the main steam system, extraction system, and drain system is determined by the moisture separator reheater 13.
This will be explained using A as an example.

Four main steam pipes 3 connected to the reactor vessel 10
3A to 33D are connected to the high pressure turbine 11. Steam discharged from the final stage of the high-pressure turbine 11 is supplied into the shell 14 of the moisture separation reheater 13A from steam inlets 18A to 18D via main steam pipes 34A and 34B. This evaporation is Ciel 1
moisture separator 17A (or moisture separator 17
B), and further heated in the first stage reheater 15A and second stage reheater 16A (or first stage reheater 15B and second stage reheater 16B). . The steam that has been reheated in this way and has a low humidity is passed through the steam outlets 19A to 19C at the top of the shell 14.
The steam is then discharged into three main steam pipes 35A to 35C connected to their steam outlets, respectively, and guided to low pressure turbines 12A to 12C. High pressure turbine 1
1 and the rotating shafts of the low pressure turbines 12A to 12C are:
Each is connected.

The bleed pipe 49 connected to the high pressure turbine 11 at a stage before the final stage of the high pressure turbine 11 is connected to the first stage.
It is connected to stage reheaters 15A and 15B. A header pipe 50 is connected to the main steam pipes 33A to 33D. The air bleed pipe 51A connected to the header pipe 50 is connected to the second stage reheater 16A, and the air bleed pipe 51B connected to the header pipe 50 is connected to the second stage reheater 16B. The steam extracted through the bleed pipe 49 is supplied to the heat transfer tubes of the second stage reheaters 15A and 15B, and the steam extracted through the bleed pipes 51A and 51B is supplied to the second stage reheaters 16A and 16B. moisture separators 17A and 17B.
It is used as a heating source for the steam that has passed through the

Moisture separated from the steam by the moisture separator 17A is led from inside the shell 14 to the drain tank 52A through drain outlets 48A and 48B. Moisture separated from the steam by the moisture separator 17B is led from inside the shell 14 to the drain tank 52B through drain outlets 48C and 48D.

The first stage reheater 15A of the moisture separation reheater 13A,
The steam supplied to each heat exchanger tube of 15B and second-stage reheaters 16A and 16B is condensed into high-temperature drain water and drained into drain tanks 52C, 52D, and 52.
E and 52F, respectively.

The high temperature drain water collected in drain tanks 52A to 52F is collected in tank 45.

The moisture separation reheater 13B is also the moisture separation reheater 13
Like A, it is connected to the main steam system extraction system and drain system. The water supply piping 36 is provided with two systems, A and B systems. Moisture separation reheater 1
The drain water in the 3A drain tanks 52A to 52F is led into the tank 45 of the A system water supply system.
Drain tanks 52A to 5 of the moisture separation reheater 13B
The drain water on the 2nd floor is in tank 4 of the B system water supply system.
5.

Of the system configuration shown in FIG. 5, most of the system configuration except for the reactor vessel 10 is installed in a building containing a turbine. The configuration of the turbine building of this embodiment will be explained below based on FIGS. 1 to 4.

FIG. 3 shows a longitudinal cross section (-cross section in FIG. 1) of the turbine building 55 of this embodiment, FIG. 1 is a −, − cross section in FIG. 3, and FIG. 2 is a − cross section in FIG. It shows. The turbine building 55 is
A building 56 having an operating bed 57 (FIG. 3), a high pressure turbine 11, moisture separator reheaters 13A and 13B,
It has low pressure turbines 12A, 12B and 12C, and condensers 20A, 20B and 20C. The cross section of the building 56 has a rectangular shape. Condenser 2
0A, 20B, and 20C are installed in order in the longitudinal direction of the building 56 on the floor of the first basement floor of the building 56. G (Figure 3) is the earth's surface. Condenser 20
A to 20C are located below the operating floor 57 within the building 56. The low pressure feed water heater is the condenser 20
Four units are installed in two rows and two columns at the top of A to 20C. As mentioned above, these low-pressure feed water heaters are 6 units of A system and 6 units of B system.

A pair of pedestal legs 59A and 59B are installed between each condenser. A pair of pedestal legs 59C and 59D are installed adjacent to the condenser 20A. Further, pedestal legs 59E and 59F are installed adjacent to the condenser 20C. These pedestal legs extend upward from the first basement floor of the building 56. A pedestal frame 60 is provided spanning the upper end of each pedestal leg. A pedestal is constituted by these pedestal legs and a pedestal frame. The level of the top surface of the gantry frame 60 matches the level of the top surface of the driving floor 57, as shown in FIG.

Although not shown, the low pressure turbines 12A to 12C are housed in a turbine casing and installed on the above-mentioned pedestal. The low pressure turbine 12A is located above the condenser 20A, the low pressure turbine 12B is located above the condenser 20B, and the low pressure turbine 12C is located above the condenser 20C. The low pressure turbines 12A to 12C are installed on the above-mentioned pedestal. The high pressure turbine 11 is installed on the above-mentioned pedestal above the pedestal leg 59C. The upper half of the high-pressure turbine 11 and the low-pressure turbines 12A to 12C protrude above the operating bed 57. The upper lid of the turbine casing housing each turbine is removable and located above the operating floor 57. The generator 58 is installed on the pedestal above the pedestal legs 59E and 59F. The rotating shafts of the high pressure turbine 11 and the low pressure turbines 12A to 12C are connected. The rotation axis of the generator 58 is
It is separably connected to the rotating shaft of the low pressure turbine 12C via a coupling.

The moisture separation reheaters 13A and 13B are located in the building 56.
Inside the building 56, the second floor 61 (Fig. 3) and the operating floor 5
7 and is suspended from the driving floor 57. In addition, moisture separation reheaters 13A and 13B
is arranged so as to be located closer to the high pressure turbine 11 than the condenser 20A. Moisture separation reheater 13
A pair of pedestal legs 59C and 59D are located between A and the moisture separator reheater 13B. That is, the moisture separation reheaters 13A and 13B are located on both sides of the high-pressure turbine 11, and their axes are parallel to the rotation axis of the high-pressure turbine 11. No. 1 connected to moisture separator reheaters 13A and 13B
The respective drain tanks 52A to 52F described from pages 12 to 13 are installed on the first floor floor 62 of the building 56 near the respective moisture separator reheaters 13A and 13B (representative in FIG. 3). As an example, only the drain tank 52D is shown with a dotted line). Main steam pipes 34A, 34B shown in FIG.
35A to 35C, the piping of the extraction system and the drain system is arranged vertically within the building 56 with the rotation axis of the turbine extending downward, since the moisture separation reheaters 13A and 13B are located on both sides of the high pressure turbine 11. arranged symmetrically with respect to the plane. The main steam pipes 34A and 34B connected to the high pressure turbine 11 are
After descending below the second floor floor 61, the second floor floor 61
through the moisture separator reheater steam inlets 18A-1
Each is connected to 8D.

In this embodiment, moisture separation reheaters 13A and 13
Since B is located below the driving floor 57,
The laydown area on the operating floor 57 can be increased compared to the case where the moisture separation reheater is installed on the operating floor 57. The laydown area is an area where parts of equipment disassembled during maintenance and inspection are placed. In this embodiment, after securing a sufficient laydown area, the driving floor 57
The area above can be reduced by about 10% compared to the case where the moisture separation reheater is installed on the operating bed 57. The upper lid of the turbine casing is surrounded by a radiation shield. During maintenance and inspection of the turbine, the radiation shield, the upper cover of the turbine casing, and the turbine are removed, lifted by an overhead crane installed at the top of the building 56, and moved to a laydown area on the operating floor 57. This movement is carried out by driving bed 57.
Since there is no moisture separator reheater above, it is not limited by this. Therefore, in this embodiment, the removed parts can be moved to the destination location in a short time. In this way, the laydown area increases and the time required to move disassembled equipment parts is shortened, so in this embodiment, the time required for maintenance and inspection of equipment such as turbines is significantly shortened. Since the driving bed 57 functions as a radiation shield for the moisture separator reheaters 13A and 13B, the moisture separator reheater 13A
There is no need to separately provide a radiation shield of 13B and 13B. Operating floor 57 during maintenance and inspection of equipment such as turbines
Operators working above are not at risk of being exposed to radiation from the moisture separator reheaters 13A and 13B due to the operating bed 57. Since a heavy radiation shield for the moisture separation reheater is not required, the center of gravity of the building 56 is lowered, which improves the seismic resistance of the building 56, and also eliminates the need for reinforcement construction and concrete pouring. The construction period can be significantly shortened.

There is also no need to lift the moisture separator reheaters 13A and 13B above the operating floor 57 during installation.
This helps shorten the construction period.

Each low pressure feed water heater installed in each condenser is
It is pulled out in the direction of arrow 65 (FIG. 1) during maintenance and inspection. Since the moisture separation reheater 13A is disposed closer to the pedestal leg 59C than the condenser 20A, that is, closer to the high pressure turbine 11, the aforementioned low pressure feed water heater can be easily removed from the condenser. Its maintenance and inspection becomes easy. The moisture separation reheater 13B is also arranged closer to the high-pressure turbine 11 than the condenser 20A, similarly to the moisture separation reheater 13A. Therefore, the main steam pipe connected to the moisture separation reheater, the piping of the extraction system, and the piping of the drain system can be arranged symmetrically as described above, and the installation and maintenance of each piping is extremely easy.

The high-pressure feed water heater is installed on the second floor 61 near the side wall 67 of the building 56 facing the reactor building 66, as shown in FIG. That is, the high-pressure second-stage feed water heater 31 of system A and the high-pressure second stage water heater 31 of system B
The stage feedwater heater 31A is arranged closer to the reactor building 66 and near the side wall 67 than the moisture separation reheater 13B, which is arranged closer to the reactor building 66 than the condenser. A-system high-pressure first-stage feed water heater 30
and B system high pressure first stage feed water heater 30A is the fourth
As shown in the figure, they are installed on the first floor floor 62 almost directly below the high-pressure second stage feed water heaters 31 and 31A. High pressure first stage feed water heaters 30 and 3
0A, and high pressure second stage feed water heaters 31 and 31A
The axis direction is horizontal. In other words, those high-pressure feed water heaters are placed horizontally.

By arranging the high-pressure feed water heater in the vicinity of the side wall 67 facing the reactor building 66 side in this way,
Water supply system equipment and piping can be arranged in an orderly manner. Therefore, wasted space within the building 56 can be eliminated, and moisture separator reheaters 13A and 1
Space for installing 3B 2nd floor floor 61 and driving floor 57
We were able to secure an agreement between In particular, the high pressure first
The stage feed water heaters 30 and 30A and the high pressure second stage feed water heaters 31 and 31A are arranged one above the other as shown in FIG. Since the high-pressure second-stage feed water heaters are arranged in the axial direction, the A and B system water supply systems can be arranged without waste, and there is sufficient space to install the moisture separation reheater below the operating floor 57. can do.

〔Effect of the invention〕

Any of the present inventions can significantly shorten the maintenance and inspection period for the turbine.

[Brief explanation of the drawing]

1 shows a turbine building according to a preferred embodiment of the present invention; FIG. 3 is a cross-sectional view of FIG. 3; FIG. 2 is a cross-sectional view of FIG. 3; and FIG. 4 is a cross-sectional view of FIG. 1, FIG. 5 is a system diagram of a boiling water reactor plant to which the present invention is applied, and FIG. A vertical cross-sectional view of the moisture separation reheater, Figure 7 is a detailed system diagram near the moisture separation reheater in Figure 5, and Figure 8 is a longitudinal cross-sectional view of the moisture separation reheater.
The figure shows a system diagram of the PWR steam system, and Figure 9 is a cross-sectional view above the operating floor of the turbine building when the moisture separator reheater shown in Figure 8 is applied to a conventional boiling water reactor plant. , FIG. 10 is X- in FIG.
11 is a sectional view taken along the line XI-XI in FIG. 10. 10... Nuclear reactor vessel, 11... High pressure turbine,
12, 12A to 12C...low pressure turbine, 13,
13A, 13B... Moisture separation reheater, 14... Ciel, 15A, 15B... First stage reheater, 16
A, 16B...Second stage reheater, 17A, 17B...
...Moisture separator, 20,20A-20C...Condenser, 25-28...Low pressure feed water heater, 30,31
... High pressure feed water heater, 33, 34, 35 ... Main steam pipe, 36 ... Water supply piping, 55 ... Turbine building, 56 ... Building, 57 ... Operating floor.

Claims (1)

[Scope of Claims] 1. A building having an operating floor, a condenser installed below the operating floor in the building, and a condenser disposed with at least an upper part protruding above the operating floor surface, and a low-pressure turbine located above the water container and supplying steam to the condenser; and a low-pressure turbine installed with at least an upper part protruding above the operating floor surface, and a rotating shaft that is connected to the rotating shaft of the low-pressure turbine. In a turbine building that includes as a main component a high-pressure turbine that is connected to the high-pressure turbine, the turbine building is connected to a pipe that guides steam from the high-pressure turbine, and the introduced steam is passed through a moisture separating means and a heating means, and then passed through another pipe to the above-mentioned pipe. A turbine building, characterized in that a moisture separation reheater for passing a low-pressure turbine is installed in the building below the operating floor surface. 2. The condenser has a built-in feedwater heater, and the moisture separation reheater is installed in a position away from a pull-out space for maintenance and inspection of the feedwater heater. A turbine building according to claim 1. 3. A building with an operating floor, a condenser installed in the building below the operating floor, and a low-pressure water supply that is built into the condenser and heats the condensed cooling water from the condenser. a heater, a plurality of high-pressure feedwater heaters that heat the condensed cooling water from the low-pressure feedwater heater and pass it into the reactor vessel, and are arranged with at least an upper portion protruding above the operating floor surface, and a low pressure turbine located above the condenser;
A turbine building including as a main component a high-pressure turbine installed with at least an upper portion protruding above the operating floor surface and having a rotating shaft connected to the rotating shaft of the low-pressure turbine; and the reactor vessel. In a nuclear power plant consisting of a nuclear reactor building containing a reactor building, the moisture separation system is connected to piping that guides steam from the high-pressure turbine, passes the introduced steam through moisture separation means and heating means, and passes it through other piping to the low-pressure turbine. a reheater is installed in the building below the operating floor, and the plurality of high-pressure feedwater heaters are installed in the reactor building in the turbine building below the operating floor than the moisture separation reheater. A turbine building that is characterized by being installed in close quarters and distributed vertically and horizontally.