EP3324008A1

EP3324008A1 - Steam turbine plant

Info

Publication number: EP3324008A1
Application number: EP16836946.0A
Authority: EP
Inventors: Ryota Takahashi; Issaku FUJITA; Yasuaki SHIMOHARA; Mitsumasa KADOWAKI
Original assignee: Mitsubishi Hitachi Power Systems Ltd
Current assignee: Mitsubishi Power Ltd
Priority date: 2015-08-19
Filing date: 2016-07-27
Publication date: 2018-05-23
Also published as: CN107923263B; WO2017029955A1; JP2017040198A; CN107923263A; JP6081543B1; EP3324008A4

Abstract

To provide a steam turbine plant that includes a high and intermediate-pressure turbine (21) in which a high-pressure turbine unit (25) is provided at one end in an axial direction (C) and an intermediate-pressure turbine unit (26) is provided at the other end, low-pressure turbines (22, 23) that are arranged coaxially with the high and intermediate-pressure turbine (21), a high-pressure moisture separating-heater (27) that is arranged on a side opposite to the low-pressure turbines (22, 23) in the axial direction (C) of the high and intermediate-pressure turbine (21) so as to remove moisture from steam from the high-pressure turbine unit (25) and feed steam to the intermediate-pressure turbine unit (26), and a low-pressure moisture separating-heater (28) that removes moisture from steam from the intermediate-pressure turbine unit (26) and feeds steam to the low-pressure turbines (22, 23). By having such a configuration, simplification of the structure and decrease of the facility cost are achieved.

Description

Field

The present invention relates to a steam turbine plant that is used in a nuclear power plant and a thermal power plant.

Background

For example, a nuclear power plant feeds steam generated in a steam generator to a steam turbine to generate power by driving a power generator connected thereto. Generally, a steam turbine includes a high-pressure turbine and a low-pressure turbine, and steam used in the high-pressure turbine is heated after moisture is removed by a moisture separating-heater, and is fed to the low-pressure turbine. Steam used in the steam turbine is cooled by a condenser to become condensate, and the condensate is heated by a low-pressure feed-water heater, a high-pressure feed-water heater, and the like, and is returned to the steam generator.
In such a nuclear power plant, as a system taking further performance improvement into consideration, a steam turbine (a high-pressure turbine, an intermediate-pressure turbine, a low-pressure turbine), a power generator, a high-pressure moisture separating-heater, and a low-pressure moisture separating-heater are arranged in one turbine building. As such a steam turbine plant, for example, there is a steam turbine plant described in Patent Literature 1 listed below.

Citation List

Patent Literature

Patent Literature 1: Japanese Laid-open Patent Publication No. 62-218606 A

Summary

Technical Problem

In a conventional steam turbine plant, if it is attempted to realize a system configuration described in Patent Literature 1, in the high-pressure moisture separating-heater and the low-pressure moisture separating-heater, devices and pipes become large in order to suppress an increase of a flow velocity of steam to be processed. Therefore, it is a common procedure that the high-pressure moisture separating-heater and the low-pressure moisture separating-heater are arranged at a position away from the steam turbine or on a floor level different from that of the steam turbine. Due to this configuration, there are problems that the turbine building becomes large to increase the facility cost, and maintainability of the respective moisture separating-heaters is not good.
The present invention has been achieved in view of the above problems, and an object of the present invention is to provide a steam turbine plant that realizes simplification of its structure and reduction of the facility cost.

Solution to Problem

To achieve the above object, a steam turbine plant according to the present invention includes a high and intermediate-pressure turbine in which a high-pressure turbine unit is provided at one end in an axial direction and an intermediate-pressure turbine unit is provided at the other end, a low-pressure turbine that is arranged coaxially with the high and intermediate-pressure turbine, a high-pressure moisture separator that is arranged on a side opposite to the low-pressure turbine in the axial direction of the high and intermediate-pressure turbine so as to remove moisture from steam from the high-pressure turbine unit and feed steam to the intermediate-pressure turbine unit, and a low-pressure moisture separator that removes moisture from steam from the intermediate-pressure turbine and feeds steam to the low-pressure turbine.
Accordingly, by arranging the high-pressure moisture separator on the side opposite to the low-pressure turbine in the axial direction of the high and intermediate-pressure turbine, the high-pressure moisture separator can be arranged near the high and intermediate-pressure turbine and the low-pressure turbine. Therefore, a pipe length becomes short to simplify the structure, the facility cost can be reduced, and the turbine building can be made small.
In the steam turbine plant according to the present invention, the high-pressure moisture separator is arranged along a direction intersecting with the axial direction.
Accordingly, by arranging the high-pressure moisture separator in a direction intersecting with the high and intermediate-pressure turbine and the low-pressure turbine, a space in the axial direction can be effectively used, and the turbine building can be made small.
In the steam turbine plant according to the present invention, a deaerator is arranged on a side opposite to the low-pressure turbine in the axial direction of the high and intermediate-pressure turbine, and the high-pressure moisture separator is arranged between the high and intermediate-pressure turbine and the deaerator.
Accordingly, the high-pressure moisture separator is arranged between the high and intermediate-pressure turbine and the deaerator, and thus not only the high-pressure moisture separator but also the deaerator can be arranged efficiently.
In the steam turbine plant according to the present invention, the high-pressure moisture separator is arranged along the axial direction.
Accordingly, by arranging the high-pressure moisture separator in parallel with the high and intermediate-pressure turbine and the low-pressure turbine, longitudinal directions of various devices can be aligned, thereby realizing effective use of space.
In the steam turbine plant according to the present invention, the high-pressure moisture separator is arranged on a floor same that of the high and intermediate-pressure turbine, the low-pressure turbine, and the low-pressure moisture separator.
Accordingly, by arranging the high-pressure moisture separator on the same floor as the high and intermediate-pressure turbine, the low-pressure turbine, and the low-pressure moisture separator, a pipe length of a connecting pipe can be reduced to decrease the facility cost.
In the steam turbine plant according to the present invention, the high-pressure moisture separator is arranged on a floor vertically different from a floor where the high and intermediate-pressure turbine and the low-pressure turbine are arranged.
Accordingly, by arranging the high-pressure moisture separator on a floor vertically different from a floor where the high and intermediate-pressure turbine and the low-pressure turbine are arranged, the pipe length of the connecting pipe can be ensured to decrease adverse effect due to thermal stress.
In the steam turbine plant according to the present invention, the high-pressure moisture separator is arranged in plural in parallel.
accordingly, by arranging a plurality of high-pressure moisture separators in parallel, steam from the high-pressure turbine unit can be processed with good balance.
In the steam turbine plant according to the present invention, the high-pressure moisture separator is a high-pressure moisture separating-heater.
Therefore, steam can be heated appropriately. Advantageous Effects of Invention
According to the steam turbine plant of the present invention, because a high-pressure moisture separator is arranged on a side opposite to a low-pressure turbine in an axial direction of a high and intermediate-pressure turbine, the structure of the steam turbine plant can be simplified, and the facility cost can be reduced. Brief Description of Drawings

FIG. 1 is a schematic configuration diagram illustrating a nuclear power plant according to a first embodiment.
FIG. 2 is a schematic diagram illustrating a flow of condensate and steam in a steam turbine plant according to the first embodiment.
FIG. 3 is a plan view illustrating an arrangement of the steam turbine plant according to the first embodiment.
FIG. 4 is a front view illustrating an arrangement of the steam turbine plant.
FIG. 5 is a front view illustrating another arrangement of the steam turbine plant.
FIG. 6 is a plan view illustrating an arrangement of a steam turbine plant according to a second embodiment.
FIG. 7 is a plan view illustrating an arrangement of a steam turbine plant according to a third embodiment. Description of Embodiments

Exemplary embodiments of a steam turbine plant according to the present invention will be described below in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments, and when there are a plurality of embodiments, embodiments constituted by combining the respective embodiments are also included in the present invention.

[First embodiment]

FIG. 1 is a schematic configuration diagram illustrating a nuclear power plant according to a first embodiment.
A nuclear reactor according to the first embodiment is a pressurized water reactor (PWR) that uses light water as a reactor coolant and a neutron moderator, turns the light water to high-temperature and high-pressure water that does not boil over the entire reactor internal to generate steam by heat exchange by feeding the high-temperature and high-pressure water to a steam generator, and feeds the steam to a turbine generator to generate power.
In the nuclear power plant including the pressurized water reactor according to the first embodiment, as illustrated in FIG. 1, a pressurized water reactor 12 and a steam generator 13 are housed in a containment 11. The pressurized water reactor 12 and the steam generator 13 are coupled with each other via pipes 14 and 15. A pressurizer 16 is provided on the pipe 14, and a primary cooling-water pump 17 is provided on the pipe 15. In this case, light water is used as a moderator and primary cooling water (coolant), and a primary cooling system is controlled to maintain a high-pressure state of about 150 pascals to 160 pascals by the pressurizer 16, in order to suppress boiling of the primary cooling water in the reactor core. Accordingly, in the pressurized water reactor 12, light water as primary cooling water is heated by low-enriched uranium or MOX as fuel (nuclear fuel), and the high-temperature primary cooling water is fed to the steam generator 13 through the pipe 14 in a state of being maintained at a predetermined high pressure by the pressurizer 16. In the steam generator 13, heat exchange is performed between the high-temperature and high-pressure primary cooling water and secondary cooling water, and the cooled primary cooling water is returned to the pressurized water reactor 12 through the pipe 15.
The steam generator 13 is coupled with a steam turbine 19 via a pipe 18, and a main steam-isolation valve 20 is provided on the pipe 18. The steam turbine 19 includes a high and intermediate-pressure turbine 21 and two low- pressure turbines 22 and 23, and is connected with a power generator 24 coaxially. The high and intermediate-pressure turbine 21 includes a high-pressure turbine unit 25 and an intermediate-pressure turbine unit 26, and a high-pressure moisture separating-heater 27 is provided between the high-pressure turbine unit 25 and the intermediate-pressure turbine unit 26. A low-pressure moisture separating-heater 28 is provided between the high and intermediate-pressure turbine 21 (the intermediate-pressure turbine unit 26) and the low- pressure turbines 22 and 23. That is, the pipe 18 from the steam generator 13 is connected to an inlet port of the high-pressure turbine unit 25, a steam pipe 29 is connected from an outlet port of the high-pressure turbine unit 25 to an inlet port of the high-pressure moisture separating-heater 27, and a steam pipe 30 is connected from an outlet port of the high-pressure moisture separating-heater 27 to an inlet port of the intermediate-pressure turbine unit 26. Further, a steam pipe 31 is connected from an outlet port of the intermediate-pressure turbine unit 26 to an inlet port of the low-pressure moisture separating-heater 28, and a steam pipes 32 are connected from an outlet port of the low-pressure moisture separating-heater 28 to respective inlet ports of the low- pressure turbines 22 and 23.
The steam turbine 19 is provided with condensers 33 and 34 below the low- pressure turbines 22 and 23. The condensers 33 and 34 cool steam used in the low- pressure turbines 22 and 23 by cooling water, and condense the steam to turn the steam into condensate. As the cooling water, seawater is used. The condensers 33 and 34 are coupled with a water-intake pipe 35 and an exhaust pipe 36 that respectively feeds and discharges cooling water. The water-intake pipe 35 includes a circulating water pump 37, and the other end thereof is arranged in the sea together with that of the exhaust pipe 36.
The condensers 33 and 34 are connected with a pipe 38, and a condensate pump 39, a gland condenser 40, a condensate demineralizer 41, a condensate booster pump 42, and low-pressure feed- water heaters 43, 44, 45, and 46 are provided on the pipe 38 in this order along a flow direction of condensate. The first low-pressure feed-water heater 43 and the second low-pressure feed-water heater 44 are provided in the condensers 33 and 34, respectively, and the condensate is heated with the steam used in the low- pressure turbines 22 and 23. Further, the third low-pressure feed-water heater 45 and the fourth low-pressure feed-water heater 46 are provided outside the condensers 33 and 34. In the third low-pressure feed-water heater 45, the condensate is heated with the steam extracted from the low- pressure turbines 22 and 23. In the fourth low-pressure feed-water heater 46, the condensate is heated with the steam discharged from the intermediate-pressure turbine unit 26.
A deaerator 47, a main feed-water pump 48, a high-pressure feed-water heater 49, and a main feed-water control valve 50 are provided in this order on the pipe 38 on a downstream side of the fourth low-pressure feed-water heater 46 along the flow direction of condensate.
Therefore, the steam generated by the steam generator 13 by performing heat exchange between the high-temperature and high-pressure primary cooling water and the secondary cooling water is fed to the steam turbine 19 through the pipe 18, and to operate the high and intermediate-pressure turbine 21 and the low- pressure turbines 22 and 23, thereby obtaining a rotation force. The power generator 24 is driven by the resulting rotation force so as to perform power generation. At this time, after the steam from the steam generator 13 has driven the high-pressure turbine unit 25, moisture contained in the steam is removed by the high-pressure moisture separating-heater 27, and the steam is heated to drive the intermediate-pressure turbine unit 26. Further, after the steam has driven the intermediate-pressure turbine unit 26, moisture contained in the steam is removed by the low-pressure moisture separating-heater 28, and the steam is heated to drive the low- pressure turbines 22 and 23. The steam having driven the low- pressure turbines 22 and 23 is then cooled by the condensers 33 and 34 using seawater to be condensate, which flows in the pipe 38 by the condensate pump 39, and is returned to the steam generator 13 through the gland condenser 40, the condensate demineralizer 41, the low-pressure feed- water heaters 43, 44, 45, and 46, the deaerator 47, the high-pressure feed-water heater 49, and the like.
The flow of condensate and steam in the high and intermediate-pressure turbine 21, the low- pressure turbines 22 and 23, the high-pressure moisture separating-heater 27, the low-pressure moisture separating-heater 28, and the low-pressure feed- water heaters 43, 44, 45, and 46 is described here. FIG. 2 is a schematic diagram illustrating a flow of condensate and steam in the steam turbine plant according to the first embodiment.
As illustrated in FIG. 2, the steam pipe 31 from the outlet port of the intermediate-pressure turbine unit 26 to the inlet port of the low-pressure moisture separating-heater 28 is connected with a base end of a steam branch pipe 51 branched from a middle-stream portion of the steam pipe 31, and a tip end of the steam branch pipe 51 is connected to the fourth low-pressure feed-water heater 46. Further, a tip end of a bleed air pipe 52 from the low- pressure turbines 22 and 23 is connected to the third low-pressure feed-water heater 45. Therefore, the third low-pressure feed-water heater 45 heats the condensate with the steam extracted from the low- pressure turbines 22 and 23, and the fourth low-pressure feed-water heater 46 heats the condensate with the steam discharged from the intermediate-pressure turbine unit 26.
In the respective low-pressure feed- water heaters 43, 44, 45, and 46, steam heats and condenses condensate to generate drain (water). Therefore, a drain pipe 53 is connected from the fourth low-pressure feed-water heater 46 to the third low-pressure feed-water heater 45, a drain pipe 54 is connected from the third low-pressure feed-water heater 45 to the second low-pressure feed-water heater 44, and a drain pipe 55 is connected from the second low-pressure feed-water heater 44 to the first low-pressure feed-water heater 43. A drain pipe 56 is connected from the first low-pressure feed-water heater 43 to a point between the first low-pressure feed-water heater 43 and the second low-pressure feed-water heater 44 in the pipe 38, and a drain pump 57 is provided on the drain pipe 56.
In the steam turbine plant according to the first embodiment configured in this manner, the high-pressure moisture separating-heater 27, the low-pressure moisture separating-heater 28, and the like are efficiently arranged with respect to the steam turbine 19.
FIG. 3 is a plan view illustrating an arrangement of the steam turbine plant according to the first embodiment, and FIG. 4 is a front view illustrating an arrangement of the steam turbine plant.
As illustrated in FIG. 3 and FIG. 4, the steam turbine plant according to the first embodiment includes the high and intermediate-pressure turbine 21, the low- pressure turbines 22 and 23, the power generator 24, the high-pressure moisture separating-heater 27, and the low-pressure moisture separating-heater 28.
A turbine building (not illustrated) includes a plurality of floor levels, a base 62 is laid in a central part of a floor 61 in a predetermined floor level, and the high and intermediate-pressure turbine 21, the two low- pressure turbines 22 and 23, and the power generator 24 are arranged coaxially along an axial direction C on the base 62.
The low-pressure moisture separating-heater 28 is configured by two low-pressure moisture separating- heaters 28a and 28b, and is arranged on the floor 61 so as to be located on opposite sides in a width direction (the vertical direction in FIG. 3) of the high and intermediate-pressure turbine 21. The respective low-pressure moisture separating- heaters 28a and 28b are arranged in parallel with respect to the axial direction C, with a predetermined gap from the high and intermediate-pressure turbine 21 and the respective low- pressure turbines 22 and 23. The respective low-pressure moisture separating- heaters 28a and 28b remove moisture from the steam discharged from the high and intermediate-pressure turbine 21 and feed the steam to the low- pressure turbines 22 and 23. Two steam pipes 31a and 31b are extended from an outlet port of the intermediate-pressure turbine unit 26 (see FIG. 2), and tip ends thereof are connected to respective inlet portions of the low-pressure moisture separating- heaters 28a and 28b. Steam pipes 32a and 32b are respectively connected from outlet ports of the low-pressure moisture separating- heaters 28a and 28b to the respective inlet portions of the low- pressure turbines 22 and 23. Further, the respective low-pressure moisture separating- heaters 28a and 28b are respectively provided with a heat-transfer pipe group as a heating source that heats the steam, and the steam from the steam generator 13 circulates therein.
The high-pressure moisture separating-heater 27 is configured by one high-pressure moisture separating-heater, and is arranged on a side opposite to the low- pressure turbines 22 and 23 in the axial direction C of the high and intermediate-pressure turbine 21. The high-pressure moisture separating-heater 27 is arranged on the floor 61 adjacent to the high and intermediate-pressure turbine 21 along a direction intersecting with the axial direction C. The high-pressure moisture separating-heater 27 removes moisture from the steam discharged from the high-pressure turbine unit 25 and feeds the steam to the intermediate-pressure turbine unit 26. The steam pipe 29 is extended from the outlet port of the high-pressure turbine unit 25 (see FIG. 2), and a tip end thereof is connected to the inlet port of the high-pressure moisture separating-heater 27. The steam pipe 30 is connected from the outlet port of the high-pressure moisture separating-heater 27 to the inlet port of the intermediate-pressure turbine unit 26. Further, the high-pressure moisture separating-heater 27 is provided with the heat-transfer pipe group as a heating source that heats the steam, and the steam from the steam generator 13 circulates therein.
The deaerator 47 is arranged on the floor 61 on one side in the axial direction C of the high and intermediate-pressure turbine 21, along the direction intersecting with the axial direction C of the high and intermediate-pressure turbine 21. The deaerator 47 removes impurities such as dissolved oxygen and non-condensable gas (ammonia gas) from condensate (feed-water) from the fourth low-pressure feed-water heater 46 (see FIG. 2). The high-pressure moisture separating-heater 27 is arranged between the high and intermediate-pressure turbine 21 and the deaerator 47 with a predetermined gap from the high and intermediate-pressure turbine 21 and the deaerator 47.
In this case, the high and intermediate-pressure turbine 21, the low- pressure turbines 22 and 23, the power generator 24, the high-pressure moisture separating-heater 27, and the low-pressure moisture separating-heaters 28 (28a, 28b), and the deaerator 47 are arranged on the same floor 61.
In the embodiment described above, the high-pressure moisture separating-heater 27 is arranged between the high and intermediate-pressure turbine 21 and the deaerator 47 on the same floor 61 as the high and intermediate-pressure turbine 21 and the low- pressure turbines 22 and 23. However, the present invention is not limited to this configuration. FIG. 5 is a front view illustrating another arrangement of the steam turbine plant.
As illustrated in FIG. 5, a floor 63 is provided on a lower level of the floor 61. The high-pressure moisture separating-heater 27 is arranged on the lower floor 63 that is different from the floor 61 where the high and intermediate-pressure turbine 21 and the low- pressure turbines 22 and 23 are installed. However, as described above, the high-pressure moisture separating-heater 27 is arranged on the side opposite to the low- pressure turbines 22 and 23 in the axial direction C of the high and intermediate-pressure turbine 21, along the direction intersecting with the axial direction C. The deaerator 47 is arranged on the floor 61 on the one side in the axial direction C of the high and intermediate-pressure turbine 21, along the direction intersecting with the axial direction C of the high and intermediate-pressure turbine 21. The high-pressure moisture separating-heater 27 is arranged on the floor 63 on one side in the axial direction C of the high and intermediate-pressure turbine 21, along the direction intersecting with the axial direction C of the high and intermediate-pressure turbine 21. Therefore, the high-pressure moisture separating-heater 27 is located below the deaerator 47.
Accordingly, in the turbine plant according to the present embodiment, one high-pressure moisture separating-heater 27 is arranged on the floor 63 on the side opposite to the low- pressure turbines 22 and 23 in the axial direction C of the high and intermediate-pressure turbine 21, along the direction intersecting with the axial direction C, adjacent to the high and intermediate-pressure turbine 21. In this manner, the high-pressure moisture separating-heater 27 can be arranged efficiently near the high and intermediate-pressure turbine 21, and the pipe length of the steam pipes 29 and 30 becomes short to simplify the structure. Further, because only one high-pressure moisture separating-heater 27 is used, the maintainability is improved, and the facility cost is decreased.
As illustrated in FIG. 1 to FIG. 3, steam fed from the steam generator 13 through the pipe 18 drives the high-pressure turbine unit 25 of the high and intermediate-pressure turbine 21, and is fed to the high-pressure moisture separating-heater 27 by the steam pipe 29, where the steam is heated after moisture is removed therefrom. After the steam processed in the high-pressure moisture separating-heater 27 drives the intermediate-pressure turbine unit 26, the steam is fed to the low-pressure moisture separating-heater 28 by the steam pipe 30, where the steam is heated after moisture is removed therefrom. The steam processed in the low-pressure moisture separating-heater 28 is then sent by the low- pressure turbines 22 and 23 by the steam pipes 32 to drive the low- pressure turbines 22 and 23.
At this time, the steam discharged from the intermediate-pressure turbine unit 26 is then sent by the low-pressure moisture separating-heater 28 by the steam pipe 31 (31a, 31b), and is also then sent by the fourth low-pressure feed-water heater 46 by the steam branch pipe 51. Further, the steam extracted from the low- pressure turbines 22 and 23 is then sent by the third low-pressure feed-water heater 45 by the bleed air pipe 52. Accordingly, the third low-pressure feed-water heater 45 heats the condensate (feed-water) flowing in the pipe 38 with the steam from the low- pressure turbines 22 and 23, and the fourth low-pressure feed-water heater 46 heats the condensate (feed-water) heated by the third low-pressure feed-water heater 45 and flowing in the pipe 38 with the steam from the intermediate-pressure turbine unit 26.
In this manner, in the steam turbine plant according to the first embodiment, the high and intermediate-pressure turbine 21 in which the high-pressure turbine unit 25 is provided at one end in the axial direction C and the intermediate-pressure turbine unit 26 is provided at the other end, the low- pressure turbines 22 and 23 arranged coaxially with the high and intermediate-pressure turbine 21, the high-pressure moisture separating-heater 27 that is arranged on the side opposite to the low- pressure turbines 22 and 23 in the axial direction C of the high and intermediate-pressure turbine 21 to remove moisture from the steam from the high-pressure turbine unit 25 and feed the steam to the intermediate-pressure turbine unit 26, and the low-pressure moisture separating-heater 28 that removes moisture from the steam from the intermediate-pressure turbine unit 26 and feeds the steam to the low- pressure turbines 22 and 23 are provided.
Therefore, the high-pressure moisture separating-heater 27 can be arranged near the high and intermediate-pressure turbine 21 and the low- pressure turbines 22 and 23, thereby enabling to shorten the pipe length of the steam pipes 29 and 30 that connect the high-pressure moisture separating-heater 27 with the high and intermediate-pressure turbine 21 and simplify the structure. Further, the facility cost can be decreased, and the turbine building can be made small.
In the steam turbine plant according to the first embodiment, the high-pressure moisture separating-heater 27 is arranged along the direction intersecting with the axial direction C. Therefore, the lengths of various devices in the axial direction C in the high and intermediate-pressure turbine 21 can be reduced to realize effective use of the space, thereby enabling to realize a small turbine building. Further, a maintenance space can be secured at the end in the longitudinal direction of the high-pressure moisture separating-heater 27, thereby enabling to improve the maintainability of the high-pressure moisture separating-heater 27.
In the steam turbine plant according to the first embodiment, the deaerator 47 is arranged on the side opposite to the low- pressure turbines 22 and 23 in the axial direction C of the high and intermediate-pressure turbine 21, and the high-pressure moisture separating-heater 27 is arranged between the high and intermediate-pressure turbine 21 and the deaerator 47. Accordingly, not only the high-pressure moisture separating-heater 27 but also the deaerator 47 can be efficiently arranged within a limited space.
In the steam turbine plant according to the first embodiment, the high-pressure moisture separating-heater 27 is arranged on the same floor 61 as the high and intermediate-pressure turbine 21, the low- pressure turbines 22 and 23, and the low-pressure moisture separating-heater 28. Accordingly, the pipe lengths of the steam pipes 29, 30, and 31 can be reduced to decrease the facility cost.
In the steam turbine plant according to the first embodiment, the high-pressure moisture separating-heater 27 is arranged on the floor 63 vertically different from the floor where the high and intermediate-pressure turbine 21 and the low- pressure turbines 22 and 23 are arranged. Accordingly, long pipe lengths of the steam pipes 29, 30, and 31 can be ensured, thereby enabling to alleviate adverse effect due to thermal stress.
In the present embodiment, the high-pressure moisture separating-heater 27 is arranged on the side opposite to the low- pressure turbines 22 and 23 in the axial direction C of the high and intermediate-pressure turbine 21, along the direction intersecting with the axial direction C. However, it suffices that the position in the longitudinal direction of the high-pressure moisture separating-heater 27 is set as appropriate according to the peripheral devices. For example, it is logical to arrange the high-pressure moisture separating-heater 27 at a central position in a width direction (a direction intersecting with the axial direction C) of the high and intermediate-pressure turbine 21, while taking connection of the high-pressure turbine pipe into consideration. However, the high-pressure moisture separating-heater 27 can be also arranged by being offset on one side in the width direction of the high and intermediate-pressure turbine 21.

[Second embodiment]

FIG. 6 is a plan view illustrating an arrangement of a steam turbine plant according to a second embodiment. Members having functions identical to those of the embodiment described above are denoted by like reference signs and redundant explanations thereof will be omitted.
The steam turbine plant according to the second embodiment includes, as illustrated in FIG. 6, the high and intermediate-pressure turbine 21, the low-pressure turbine 22, the steam pipe 31, the high-pressure moisture separating-heater 27, and the low-pressure moisture separating-heater 28.
The low-pressure moisture separating-heater 28 is configured by two low-pressure moisture separating- heaters 28a and 28b, which are arranged on the floor 61 so as to be located on opposite sides in the width direction of the high and intermediate-pressure turbine 21. Further, the high-pressure moisture separating-heater 27 is configured by two high-pressure moisture separating- heaters 27a and 27b, which are arranged on the side opposite to the low-pressure turbine 22 in the axial direction C of the high and intermediate-pressure turbine 21. The high-pressure moisture separating- heaters 27a and 27b are arranged on the floor 61 along a direction intersecting with the axial direction C, adjacent to the high and intermediate-pressure turbine 21. The high-pressure moisture separating- heaters 27a and 27b are installed in plural (two in the present embodiment), and are arranged in parallel to each other with a predetermined gap therebetween.
In this manner, in the steam turbine plant according to the second embodiment, the high-pressure moisture separating-heater 27 is arranged in parallel as two high-pressure moisture separating- heaters 27a and 27b. Therefore, steam from the high-pressure turbine unit 25 can be processed with good balance.

[Third embodiment]

FIG. 7 is a plan view illustrating an arrangement of a steam turbine plant according to a third embodiment. Members having functions identical to those of the embodiments described above are denoted by like reference signs and redundant explanations thereof will be omitted.
The steam turbine plant according to the third embodiment includes, as illustrated in FIG. 7, the high and intermediate-pressure turbine 21, the low-pressure turbine 22, the steam pipe 31, the high-pressure moisture separating-heater 27, and the low-pressure moisture separating-heater 28.
The low-pressure moisture separating-heater 28 is configured by two low-pressure moisture separating- heaters 28a and 28b, which are arranged on the floor 61 so as to be located on opposite sides in the width direction of the high and intermediate-pressure turbine 21. Further, the high-pressure moisture separating-heater 27 is configured by one high-pressure moisture separating-heater, and arranged on the side opposite to the low-pressure turbine 22 in the axial direction C of the high and intermediate-pressure turbine 21. The high-pressure moisture separating-heater 27 is arranged on the floor 61 along the axial direction C adjacent to the high and intermediate-pressure turbine 21. In this case, the high-pressure moisture separating-heater 27, the high and intermediate-pressure turbine 21, and the low-pressure turbine 22 are arranged in alignment along the axial direction C.
In this manner, in the steam turbine plant according to the third embodiment, the high-pressure moisture separating-heater 27 is arranged along the axial direction C of the high and intermediate-pressure turbine 21. Accordingly, the space in the longitudinal direction of the respective high-pressure moisture separating- heaters 27 and 28 can be effectively used.
In the respective embodiments described above, the four low-pressure feed- water heaters 43, 44, 45, and 46 are provided. Among those heaters, the two low-pressure feed- water heaters 43 and 44 are respectively arranged in the condensers 33 and 34, and the two low-pressure feed- water heaters 45 and 46 are respectively arranged outside the condensers 33 and 34. However, the arrangement and the number thereof are not limited to those described in the above embodiments, and can be set as appropriate according to the size or the like of the steam turbine plant.
In the embodiments described above, steam discharged from the final stage of the intermediate-pressure turbine unit 26 is supplied to the low-pressure moisture separating-heaters 28 (28a, 28b). However, steam extracted from a middle stage of the intermediate-pressure turbine unit 26 can be supplied to the low-pressure moisture separating-heater 28s (28a, 28b).
In the embodiments described above, while the moisture separator according to the present invention has been described as a moisture separating-heater, it can be described as a moisture separator.
In the embodiments described above, while the steam turbine plant according to the present invention has been described while assuming that it is applied to a nuclear power plant, the present invention is not limited thereto, and the steam turbine plant can be also applied to other types of plants such as a thermal power plant. Reference Signs List

12 pressurized water reactor
13 steam generator
18, 38 pipe
19 steam turbine
21 high and intermediate-pressure turbine
22, 23 low-pressure turbine
24 power generator
25 high-pressure turbine unit
26 intermediate-pressure turbine unit
27 high-pressure moisture separating-heater (high-pressure moisture separator)
28, 28a, 28b low-pressure moisture separating-heater (low-pressure moisture separator)
29, 30, 31, 31a, 31b, 32, 32a, 32b steam pipe
33, 34 condenser
43 first low-pressure feed-water heater
44 second low-pressure feed-water heater
45 third low-pressure feed-water heater
46 fourth low-pressure feed-water heater
51 steam branch pipe
52 bleed air pipe
61, 63 floor
62 base
C axial direction

Claims

A steam turbine plant comprising:
a high and intermediate-pressure turbine in which a high-pressure turbine unit is provided at one end in an axial direction and an intermediate-pressure turbine unit is provided at the other end;

a low-pressure turbine that is arranged coaxially with the high and intermediate-pressure turbine;

a high-pressure moisture separator that is arranged on a side opposite to the low-pressure turbine in the axial direction of the high and intermediate-pressure turbine so as to remove moisture from steam from the high-pressure turbine unit and feed steam to the intermediate-pressure turbine unit; and

a low-pressure moisture separator that removes moisture from steam from the intermediate-pressure turbine and feeds steam to the low-pressure turbine.
The steam turbine plant according to claim 1, wherein the high-pressure moisture separator is arranged along a direction intersecting with the axial direction.
The steam turbine plant according to claim 2, wherein a deaerator is arranged on a side opposite to the low-pressure turbine in the axial direction of the high and intermediate-pressure turbine, and the high-pressure moisture separator is arranged between the high and intermediate-pressure turbine and the deaerator.
The steam turbine plant according to claim 1, wherein the high-pressure moisture separator is arranged along the axial direction.
The steam turbine plant according to any one of claims 1 to 4, wherein the high-pressure moisture separator is arranged on a floor same that of the high and intermediate-pressure turbine, the low-pressure turbine, and the low-pressure moisture separator.
The steam turbine plant according to any one of claims 1 to 4, wherein the high-pressure moisture separator is arranged on a floor vertically different from a floor where the high and intermediate-pressure turbine and the low-pressure turbine are arranged.
The steam turbine plant according to any one of claims 1 to 6, wherein the high-pressure moisture separator is arranged in plural in parallel.
The steam turbine plant according to any one of claims 1 to 7, wherein the high-pressure moisture separator is a high-pressure moisture separating-heater.