EP3696381A1

EP3696381A1 - Moisture separation facility, power plant and method for operating steam turbine

Info

Publication number: EP3696381A1
Application number: EP18892527.5A
Authority: EP
Inventors: Issaku Fujita; Ryota Takahashi
Original assignee: Mitsubishi Hitachi Power Systems Ltd
Current assignee: Mitsubishi Power Ltd
Priority date: 2017-12-21
Filing date: 2018-12-04
Publication date: 2020-08-19
Also published as: CN111373123A; JP6963492B2; JP2019112966A; WO2019124066A1; CN111373123B; EP3696381A4

Abstract

This moisture separation facility is provided with: a moisture separation heater (3) that separates the moisture content from a steam; a steam extraction pipe (5) that extracts some of the steam from the moisture separation heater (3); a heat exchanger (6) that performs a heat exchange between a heating medium and a steam which is extracted from the moisture separation heater (3) through the steam extraction pipe (5), thereby heating the steam; a heater (7) that heats the heating medium; and a steam introduction pipe (8) that introduces the steam, which has been heated by the heat exchanger (6), into a low pressure steam turbine (4) as a working fluid. This moisture separation facility is operated by the low pressure steam turbine (4), the steam from which the moisture content is separated by means of the moisture separation heater (3), and the steam which is heated by means of the heat exchanger (6).

Description

Technical Field

The present invention relates to a moisture separation facility for separating moisture from steam serving as a working fluid of a steam turbine, a power plant including the facility, and a method for operating a steam turbine.
This application claims the priority of Japanese Patent Application No. 2017-245154 filed in Japan on December 21, 2017 , the content of which is incorporated herein by reference.

Background Art

In a power plant including a steam turbine, a high-pressure turbine is driven by steam (main steam) generated in a steam generator. In a case where the main steam is close to a saturated state, a low-pressure turbine is driven by steam (cycle steam) discharged from the high-pressure turbine. Incidentally, the steam discharged from the high-pressure turbine carries out work for the high-pressure turbine. Accordingly, a heat holding amount of the steam is reduced. As a result, a portion of the steam is condensed, thereby generating moisture (wet steam). Therefore, if the steam discharged from the high-pressure turbine is introduced into the low-pressure turbine without any change, turbine blades of the low-pressure turbine are eroded by the wet steam. Moreover, thermal efficiency of the turbine is degraded. Therefore, in a power plant that handles the wet steam, a moisture separation heater is disposed between the high-pressure turbine and the low-pressure turbine. The moisture separation heater separates moisture from the steam discharged from the high-pressure turbine, and heats the steam whose moisture is separated, thereby generating superheated steam.
For example, as disclosed in PTL 1, a moisture separation heater of a power plant includes a horizontally placed cylindrical container, and a heater for heating target steam (steam discharged from a high-pressure turbine) introduced into the container by using higher temperature steam such as main steam.

Citation List

Patent Literature

[PTL 1] Japanese Patent No. 4848333

Summary of Invention

Technical Problem

In the moisture separation heater disclosed in PTL 1, the steam extracted from the high-pressure turbine and the main steam are used as heat sources so as to heat the steam. Accordingly, a temperature of the steam to be introduced into the low-pressure turbine is less likely to be higher than a temperature of the steam introduced into the high-pressure turbine.
The present invention is made in view of the above-described circumstances, and aims to provide a moisture separation facility, a power plant, and a method for operating a steam turbine, which contribute to improving thermal efficiency of the steam turbine by increasing holding heat capacity of a working fluid introduced into the steam turbine as a working fluid, and which can consequently improve power generation efficiency of the power plant.

Solution to Problem

According to the present invention, there is provided a moisture separation facility including a moisture separator that separates moisture from steam serving as a working fluid of a steam turbine, a steam extraction pipe that extracts a portion of the steam whose moisture is separated from the moisture separator, a first heat exchanger that heats the steam by performing heat exchange between the steam extracted from the moisture separator through the steam extraction pipe and a heating medium, a heater that heats the heating medium, and a steam introduction pipe that introduces the steam heated by the heat exchanger into the steam turbine as a working fluid. The steam turbine is operated by the steam whose moisture is separated in the moisture separator and the steam heated by the heat exchanger.
In the present invention, a portion of the steam whose moisture is separated in the moisture separator is extracted from the moisture separator, and the extracted steam is heated, and thereafter, is introduced into the steam turbine. The steam extracted from the moisture separator and heated by the heater is supplied to the steam turbine as the working fluid of the steam turbine, together with the steam whose moisture is separated in the moisture separator.
In the moisture separation facility according to the present invention, the moisture separator includes a cylindrical container, a separator that separates the moisture from the steam serving as the working fluid introduced into the container, a second heat exchanger that heats the steam whose moisture is separated by the separator, and a steam fetching pipe that is disposed between the separator and the second heat exchanger so as to acquire a portion of the steam whose moisture is separated by the separator. The steam fetching pipe may communicate with the steam extraction pipe.
In the present invention, the moisture is separated from the steam serving as the working fluid introduced into the cylindrical container by the separator, and dry steam whose moisture is separated is heated by the second heater, and thereafter, is introduced into the steam turbine. In this case, a portion of the dry steam whose moisture is separated is introduced into the steam extraction pipe through the steam fetching pipe, heated by the first heater, and thereafter, is introduced into the steam turbine.
In the moisture separation facility according to the present invention, the heater may heat the heating medium by using a system external heat source. In the present invention, the system external heat source is used for the heater. In this manner, compared to a case of using a heat source obtained inside the system, it is possible to increase holding heat capacity of the working fluid. Accordingly, thermal efficiency of the steam turbine can be improved.
In addition, the second heat exchanger may heat the steam whose moisture is separated by the separator by using a system internal heat source.
According to another aspect of the present invention, there is provided a power plant including a steam generator, a high-pressure steam turbine operated by steam generated in the steam generator, a moisture separator that separates moisture from the steam discharged from the high-pressure steam turbine, a low-pressure steam turbine operated by the steam whose moisture is separated in the moisture separator, a steam extraction pipe that extracts a portion of the steam whose moisture is separated from the moisture separator, a first heat exchanger that heats the steam by performing heat exchange between the steam extracted from the moisture separator through the steam extraction pipe and a heating medium, a heater that heats the heating medium, a steam introduction pipe that introduces the steam heated by the heat exchanger into the low-pressure steam turbine as a working fluid, a generator driven by the high-pressure steam turbine and the low-pressure steam turbine, and a condenser that condenses the steam discharged from the low-pressure steam turbine.
In the aspect of the power plant according to the present invention, the moisture separator may include a cylindrical container, a separator that separates the moisture from the steam serving as the working fluid introduced into the container, a second heat exchanger that heats the steam whose moisture is separated by the separator, and a steam fetching pipe that is disposed between the separator and the second heat exchanger so as to acquire a portion of the steam whose moisture is separated by the separator. The steam fetching pipe may communicate with the steam extraction pipe.
In the aspect of the power plant according to the present invention, the heater may heat the heating medium by using a system external heat source.
In addition, the second heat exchanger may heat the steam whose moisture is separated by the separator by using a system internal heat source.
According to another aspect of the present invention, there is provided a power plant including a moisture separator that separates moisture from steam generated by geothermal heat, a steam turbine operated by the steam whose moisture is separated in the moisture separator, a steam extraction pipe that extracts a portion of the steam whose moisture is separated from the moisture separator, a heat exchanger that heats the steam by performing heat exchange between the steam extracted from the moisture separator through the steam extraction pipe and a heating medium, a heater that heats the heating medium, a steam introduction pipe that introduces the steam heated by the heat exchanger into the steam turbine as a working fluid, a generator driven by the steam turbine, and a condenser that condenses the steam discharged from the steam turbine.
In another aspect of the power plant according to the present invention, the heater may heat the heating medium by using a system external heat source.
According to still another aspect of the present invention, there is provided a method for operating a steam turbine. The method includes a step of separating moisture from steam inside a moisture separator, a step of extracting a portion of the steam whose moisture is separated from the moisture separator, a step of heating the steam by performing heat exchange between the steam extracted from the moisture separator and a heating medium, and a step of introducing the steam whose moisture is separated in the moisture separator and the steam heated by the heat exchange with the heating medium into a steam turbine as a working fluid.
In the present invention, a portion of the steam whose moisture is separated in the moisture separator is extracted from the moisture separator, and the extracted steam is heated, and thereafter, is introduced into the steam turbine. The steam extracted from the moisture separator and heated by the first heater is supplied to the steam turbine as the working fluid of the steam turbine, together with the steam whose moisture is separated in the moisture separator.

Advantageous Effects of Invention

According to the present invention, a portion of the steam is extracted from the moisture separator, and the extracted steam is heated by using the separately provided first heater. Thereafter, the steam is introduced into the steam turbine. In this manner, it is possible to increase holding heat capacity of the working fluid introduced into the steam turbine in the working fluid introduced into the steam turbine as the working fluid. Therefore, thermal efficiency of the steam turbine is improved. As a result, power generation efficiency of a power generation system increases.

Brief Description of Drawings

Fig. 1 is a block diagram illustrating a first embodiment of a power plant including the present invention.
Fig. 2 is a side sectional view along a longitudinal direction of a moisture separation heater included in the power plant.
Fig. 3 is a side sectional view along a width direction of the moisture separation heater.
Fig. 4 is a side sectional view of one end portion of the moisture separation heater.
Fig. 5 is a block diagram illustrating a second embodiment of a power plant including the present invention.

Description of Embodiments

(First embodiment)

A first embodiment of a power plant including a moisture separation facility according to the present invention will be described below.
As illustrated in Fig. 1, the power plant includes a steam generator 1, a high-pressure steam turbine 2, a moisture separation heater (moisture separator) 3, a low-pressure steam turbine 4, a steam extraction pipe 5, a heat exchanger (first heat exchanger) 6, a heater 7, a steam introduction pipe 8, a generator 9, a condenser 10, a deaerator 11, a feed-water heater 12, and drain tanks 13A, 13B, and 13C.
The steam generator 1 generates high-temperature steam by heating water with a heat source such as a boiler or a reactor using fossil fuels such as oil and coal. The high-temperature steam generated in the steam generator 1 is introduced into the high-pressure steam turbine 2 from the steam generator 1 through a steam pipe L1. The high-pressure steam turbine 2 is operated by the high-temperature steam generated in the steam generator 1. The steam that carries out work for the high-pressure steam turbine 2 is introduced into the moisture separation heater 3 from the high-pressure steam turbine 2 through a steam pipe L2. In addition, a portion of the high-pressure steam introduced into the high-pressure steam turbine 2 is introduced into the feed-water heater 12 through a steam pipe L2a.
The moisture separation heater 3 includes a horizontally placed cylindrical container 31, a separator 32, heat exchangers (second heat exchangers) 33A and 33B, and a steam fetching pipe 34. The separator 32 separates moisture from the steam serving as a working fluid introduced into the container 31, from the high-pressure steam turbine 2. The steam extracted from an intermediate portion of the high-pressure steam turbine 2 is introduced into the heat exchanger 33A through a steam pipe L3, and the high-temperature steam generated in the steam generator 1 is introduced into the heat exchanger 33B through a steam pipe L4. Each of the heat exchangers 33A and 33B is a heat exchanger. The heat exchanger 33A performs heat exchange between the steam extracted from the intermediate portion of the high-pressure steam turbine 2 and the steam whose moisture is separated by the separator 32, and heats the steam serving as the working fluid whose moisture is separated. The heat exchanger 33B performs heat exchange between the superheated steam generated in the steam generator 1 and the steam heated by the heat exchanger 33A, and further heats the steam serving as the working fluid heated by the heat exchanger 33A.
The steam fetching pipe 34 is disposed between the separator 32 and the heat exchangers 33A and 33B, and acquires a portion of the steam whose moisture is separated by the separator 32. The steam fetching pipe 34 communicates with the steam extraction pipe 5. In the steam whose moisture is separated by the separator 32 in the moisture separation heater 3, the remaining steam which does not flow into the steam fetching pipe 34 is heated inside the container 31 by the heat exchangers 33A and 33B. Thereafter, the steam is introduced into the low-pressure steam turbine 4 through a steam pipe L5. The steam (including condensed water) subjected to heat exchange with the steam in the heat exchanger 33A is temporarily stored in the drain tank 13A through a drain pipe Ld1. The steam (including condensed water) subjected to heat exchange with the steam in the heat exchanger 33B is temporarily stored in the drain tank 13B through a drain pipe Ld2. In addition, the condensed water of the moisture discharged from the moisture separation heater 3 is temporarily stored in the drain tank 13C through a drain pipe Ld3.
A structure of the moisture separation heater 3 will be described in detail later.
The low-pressure steam turbine 4 is operated by the steam whose moisture is separated and heated in the moisture separation heater 3. A portion of the steam whose moisture is separated in the moisture separation heater 3 flows into the steam fetching pipe 34, and is introduced into the heat exchanger 6 through the steam extraction pipe 5. The heat exchanger 6 performs heat exchange between the steam extracted from the moisture separation heater 3 through the steam extraction pipe 5, and a heating medium, thereby heating the steam extracted from the moisture separation heater 3. The heat exchanger 6 is connected to the heater 7 via a medium pipe L6 configuring a closed system. The heater 7 heats the heating medium supplied to the heat exchanger 6. The heated medium circulates between the heat exchanger 6 and the heater 7 through the medium pipe L6. The steam heated in the heat exchanger 6 is introduced into the low-pressure steam turbine 4 through the steam introduction pipe 8, and operates the low-pressure steam turbine 4 together with the steam introduced through the steam pipe L5.
The heater 7 adopts those which use an external heat source independent of a system of the power plant according to the present embodiment, such as a solar concentrator which adopts a heliostat, and a boiler using fossil fuels or biomass fuels, for example.
The high-pressure steam turbine 2 and the low-pressure steam turbine 4 configure a single-shaft steam turbine sharing a main shaft 14. The generator 9 connected to the main shaft 14 is driven by the high-pressure steam turbine 2 and the low-pressure steam turbine 4. The steam that carries out work for the low-pressure steam turbine 4 is introduced into the condenser 10 through a steam pipe L7. The condenser 10 condenses the steam discharged from the low-pressure steam turbine 4. The water condensed in the condenser 10 is transported by a condensate pump 18, and is supplied to the deaerator 11 through a water pipe L8. The condensed water temporarily stored in the drain tank 13C is also supplied to the deaerator 11 through a drain pipe L9. The deaerator 11 removes oxygen from the water condensed in the condenser 10. The water whose oxygen is removed in the deaerator 11 is transported by a water supply pump 19, and is supplied to the feed-water heater 12 through a water pipe L10. The steam containing the condensed water temporarily stored in the drain tank 13A is introduced into the feed-water heater 12 through a drain pipe L11a, and the steam containing condensed water temporarily stored in the drain tank 13B is introduced into the feed-water heater 12 through drain pipes L11a and L11b. The feed-water heater 12 is also a heat exchanger, and performs heat exchange between the condensed water temporarily stored in the drain tanks 13A and 13B, the steam extracted from the high-pressure steam turbine 2 through the steam pipe L2a, and the water deaerated in the deaerator 11, thereby heating the deaerated water. The water heated in the feed-water heater 12 is supplied to the steam generator 1 through a water pipe L12. In addition, the water condensed by heating the deaerated water in the feed-water heater 12 is introduced into the deaerator 11 through a water pipe L13.
A structure of the moisture separation heater 3 is illustrated in Figs. 2 to 4.
The container 31 has a steam inlet 15, a steam outlet 16, and a drain discharge port 17. The container 31 internally has a steam receiving chamber 21 and steam chambers 20A and 20B. The steam chambers 20A and 20B respectively have a supply manifold chamber 22, a moisture separation chamber 23, a heating chamber 24, a drain recovery chamber 25, and a recovery manifold chamber 26.
The steam inlet 15 communicates with the steam receiving chamber 21, and steam (S) discharged from the high-pressure steam turbine 2 flows into the container 31 through the steam inlet 15. The steam outlet 16 communicates with the recovery manifold chamber 26, and steam (superheated steam HS) whose moisture is separated and heated in the steam chambers 20A and 20B is discharged from the container 31 through the steam outlet 16. The drain discharge port 17 communicates with the drain recovery chamber 25, and condensed water (D) of the moisture separated from the steam is discharged from the container 31 through the drain discharge port 17.
The steam receiving chamber 21 distributes the steam flowing into the container 31 through the steam inlet 15 to the steam chambers 20A and 20B. The steam chambers 20A and 20B separate the moisture from the steam flowing from the steam receiving chamber 21, and heat the steam whose moisture is separated. The supply manifold chamber 22 is adjacent to the steam receiving chamber 21, and steam flows into the steam receiving chamber 21 through the steam inlet 15. The moisture separation chamber 23 is disposed below the supply manifold chamber 22, and internally has a separator 32. The moisture separation chamber 23 separates the moisture from the steam flowing from the supply manifold chamber 22 by using the separator 32.
The supply manifold chamber 22 is partitioned from the moisture separation chamber 23 by a partition wall 36, and a slit 35 is formed on the partition wall 36. The moisture separation chamber 23 communicates with the supply manifold chamber 22 through the slit 35, and the steam flowing from the steam receiving chamber 21 into the supply manifold chamber 22 flows into the moisture separation chamber 23 through the slit 35. The moisture is separated by the separator 32. The separator 32 is configured so that a plurality of corrugated plates are disposed at an equal interval in a longitudinal direction of the container 31.
The moisture separation chamber 23 is partitioned from the drain recovery chamber 25 by a partition wall 38, and an opening 39 is formed on the partition wall 38. The moisture separation chamber 23 communicates with the drain recovery chamber 25 through the opening 39, and the moisture separated from the steam in the moisture separation chamber 23 is condensed and flows into the drain recovery chamber 25. The moisture is discharged from the container 31 through the drain discharge port 17, and flows into the drain tank 13B.
The heating chamber 24 is disposed above the moisture separation chamber 23, and internally has heat exchangers 33A and 33B. The heating chamber 24 is partitioned by the supply manifold chamber 22 disposed on both sides in the width direction of the container 31, the moisture separation chamber 23 disposed below the supply manifold chamber 22, and two vertical partition plates 40. The heat exchangers 33A and 33B are disposed between the two vertical partition plates 40. The heat exchanger 33A is disposed below the heat exchanger 33B, and the steam whose moisture is separated in the moisture separation chamber 23 flows upward from below in the heating chamber 24, and is heated in a process of sequentially passing through the heat exchangers 33A and 33B.
The drain recovery chamber 25 is disposed below the moisture separation chamber 23 and the heating chamber 24, communicates with the moisture separation chamber 23, and recovers the condensed water of the moisture separated from the steam. A drain pipe Ld1 is connected to the drain recovery chamber 25, and the condensed water recovered in the drain recovery chamber 25 is recovered to the drain tank 13B through the drain pipe Ld1.
The recovery manifold chamber 26 is disposed above the steam chambers 20A and 20B, and feeds the steam flowing from the heating chamber 24 through the steam outlet 16. The supply manifold chamber 22 and the heating chamber 24 are partitioned from each other by an inclined plate 41 which is continuous with an upper end of two vertical partition plates 40 that divides the heating chamber 24. The steam heated in the heating chamber 24 flows into the recovery manifold chamber 26, is discharged from the container 31 through the steam outlet 16, and is introduced into the low-pressure steam turbine 4 through the steam pipe L5.
The heat exchanger 33A has a heat transfer pipe 42 formed of a U-shaped pipe, a header 43 to which an end portion of the heat transfer pipe 42 is fixed, and a partition plate 44 which internally partitions the header 43 into a steam receiving chamber 43a and a steam recovery chamber 43b. The steam pipe L3 for supplying the steam extracted from the intermediate portion of the high-pressure steam turbine 2 to the heat transfer pipe 42 through the steam receiving chamber 43a, and the drain pipe Ld2 for recovering the steam and the condensed water which flow through the heat transfer pipe 42 from the header 43 through the steam recovery chamber 43b are connected to the header 43.
The heat exchanger 33B has a heat transfer pipe 45 formed of a U-shaped pipe, a header 46 to which an end portion of the heat transfer pipe 45 is fixed, and a partition plate 47 which internally partitions the header 46 into a steam receiving chamber 46a and a steam recovery chamber 46b. The steam pipe L4 for supplying the superheated steam generated in the steam generator 1 to the heat transfer pipe 45 through the steam receiving chamber 46a, and the drain pipe Ld2 for recovering the steam and the condensed water which flow through the heat transfer pipe 45 from the header 46 through the steam recovery chamber 46b are connected to the header 46.
The steam and the condensed water which flow into the steam recovery chamber 43b of the heat exchanger 33A and the steam recovery chamber 46b of the heat exchanger 33B are recovered to the drain tank 13A through the drain pipe Ld2.
As illustrated in Fig. 3, the steam fetching pipe 34 is disposed to protrude from a bottom portion of the container 31 between the moisture separation chamber 23 and the heating chamber 24. The steam fetching pipe 34 penetrates an outer plate and the partition wall 38 of the container 31, and is attached so that an upper end opening thereof faces the heat exchangers 33A and 33B. The steam extraction pipe 5 is connected to a lower end of the steam fetching pipe 34. The steam flowing from the supply manifold chamber 22 into the moisture separation chamber 23 changes a flowing direction along the partition wall 38 inside the moisture separation chamber 23. The moisture is separated in the separator 32, thereby generating dry steam. Next, the flowing direction converged to the center of the container 31 in the width direction is changed upward, and the steam flows into the heating chamber 24. At this time, an opening end of the steam fetching pipe 34 is oriented upward. Accordingly, the condensed water of moisture is unlikely to flow into the opening end. The steam flowing into the heating chamber 24 is heated in a process of sequentially passing through the heat exchangers 33A and 33B.
In the power plant configured as described above, the steam discharged from the high-pressure steam turbine 2 is introduced into the moisture separation heater 3, and a portion of the steam whose moisture is separated in the moisture separation heater 3 is extracted from the moisture separation heater 3. The extracted steam is heated by the heat exchanger 6. The heating medium of the heat exchanger 6 is heated in the heater 7. The heat source of the heater 7 adopts an external heat source independent of a system of the power plant according to the present embodiment, such as a solar concentrator which adopts a heliostat, and a boiler using fossil fuels or biomass fuels, for example.
The remaining steam whose moisture is separated in the moisture separation heater 3 is introduced into the low-pressure steam turbine 4 as the working fluid of the low-pressure steam turbine 4, and the steam heated by the heat exchanger 6 is supplied to the low-pressure steam turbine 4 as the working fluid of the low-pressure steam turbine 4. As the heat source of the heat exchanger 6, it is possible to adopt an external heat source which does not use the steam derived from the steam generator 1. In this manner, according to the above-described power plant, the holding heat capacity of the steam serving as the working fluid introduced into the low-pressure steam turbine 4 as the working fluid can be increased, compared to a case where the heat source of the steam obtained inside a closed system is used as the heat source of the heater 7, and the thermal efficiency of the steam turbine can be improved.

(Second embodiment)

A second embodiment of a power plant including the moisture separation facility according to the present invention will be described below.
The power plant according to the present embodiment is a power plant which utilizes geothermal heat. As illustrated in Fig. 5, the power plant includes a moisture separator 71, a steam turbine 72, a steam extraction pipe 73, a heat exchanger 74, and a heater (first heater) 75, a steam introduction pipe 76, a generator 77, a condenser 78, and a cooling tower 79.
The steam ejected from a production well W1 of the steam generated by geothermal heat is introduced into the moisture separator 71 through a steam pipe L21. The moisture separator 71 includes a vertically placed cylindrical container 71a and a steam fetching pipe 71b. The steam introduced into the moisture separator 71 is separated into the moisture inside the cylindrical container 71a. The steam fetching pipe 71b is erected on a bottom surface of the vertically placed container 71a, and the steam extraction pipe 73 is connected to a top of the container 71a. The steam extraction pipe 73 acquires a portion of the steam whose moisture is separated inside the container 71a. In the steam whose moisture is separated inside the container 71a, the remaining steam which does not flow into the steam extraction pipe 73 is introduced into the steam turbine 72 from the steam fetching pipe 71b through a steam pipe L22. The condensed water of the moisture is temporarily stored on the bottom of the container 71a.
The steam turbine 72 is operated by the steam whose moisture is separated in the moisture separator 71. A portion of the steam whose moisture is separated in the moisture separator 71 is introduced into the heat exchanger 74 through the steam extraction pipe 73. The heat exchanger 74 performs heat exchange between the steam extracted from the moisture separator 71 through the steam extraction pipe 73, and the heating medium, and heats the steam extracted from the moisture separator 71. The heating medium is connected to the heater 75 via a medium pipe L23 configuring a closed system. The heater 75 heats the heating medium to be supplied to the heat exchanger 74. The heated medium circulates between the heat exchanger 74 and the heater 75 through the medium pipe L23. The steam heated in the heat exchanger 74 is introduced into the steam turbine 72 through the steam introduction pipe 76, and operates the steam turbine 72 together with the steam introduced through the steam pipe L22.
As in the first embodiment, the heater 7 adopts those which use a heat source independent of a system of the power plant according to the present embodiment, such as a solar concentrator which adopts a heliostat, and a boiler using fossil fuels or biomass fuels, for example.
The generator 77 connected to the main shaft of the steam turbine 72 is driven by the steam turbine 72. The steam that carries out work for the steam turbine 72 is introduced into the condenser 78 through a steam pipe L24. The condenser 78 condenses the steam discharged from the steam turbine 72. The cooling tower 79 cools the high-temperature water condensed in the condenser 78. The condenser 78 internally has a heat exchanger 78a that condenses the steam by performing heat exchange between the water cooled in the cooling tower 79 and the steam discharged from the steam turbine 72. The cooling tower 79 internally has a header 79a for spraying the high-temperature water condensed in the condenser 78. The water condensed in the condenser 78 is supplied to the cooling tower 79 through a water pipe L25. The high-temperature condensed water supplied to the cooling tower 79 is sprayed from the header 79a, and is cooled by heat exchange with the air which rises inside the tower. The water cooled in the cooling tower 79 is supplied to the condenser 78 through the water pipe L26, is introduced into the heat exchanger 78a, and is subjected to heat exchange with the steam discharged from the steam turbine 72, thereby condensing the steam.
The condensed water temporarily stored on the bottom of the container 71a in the moisture separator 71 is introduced into an injection well W2 through a water pipe L27, and is injected underground. In addition, the cooling water stored on the bottom in the cooling tower 79 is also introduced into the injection well W2 through a water pipe L28, and is injected underground.
In the power plant configured as described above, the steam ejected from the production well W1 is introduced into the moisture separator 71, and a portion of the steam whose moisture is separated in the moisture separator 71 is extracted from the moisture separator 71. The extracted steam is heated by the heat exchanger 74. The heating medium of the heat exchanger 74 is heated in the heater 75. The heat source adopts an external heat source independent of a system of the power plant according to the present embodiment, such as a solar concentrator which adopts a heliostat, and a boiler using fossil fuels or biomass fuels, for example.
The remaining steam whose moisture is separated in the moisture separator 71 is introduced into the steam turbine 72 as the working fluid for the steam turbine 72, and the steam heated by the heat exchanger 74 is supplied to the steam turbine 72 as the working fluid of the steam turbine 72. As the heat source of the heat exchanger 74, it is possible to adopt an external heat source which is not steam ejected from the production well W1. In this manner, according to the power plant, it is possible to increase the holding heat capacity of the steam serving as the working fluid introduced into the steam turbine 72 as the working fluid. Therefore, thermal efficiency of the steam turbine is improved.
Hitherto, the preferred embodiments according to the present invention have been described. However, the present invention is not limited to the above-described embodiments. Additions, omissions, substitutions, and other modifications of the configurations can be made within the scope not departing from the gist of the present invention. The present invention is not limited by the above description, and is limited only by the matters disclosed in the appended claims.

Industrial Applicability

The present invention relates to a moisture separation facility for separating moisture from steam serving as a working fluid of a steam turbine, a power plant including the facility, and a method for operating a steam turbine.
According to the present invention, it is possible to contribute to improving thermal efficiency of the steam turbine by increasing holding heat capacity of a working fluid introduced into the steam turbine as a working fluid, and it is possible to consequently improve power generation efficiency of the power plant.

Reference Signs List

1:: steam generator
2:: high-pressure steam turbine
3:: moisture separator heater (moisture separator)
4:: low-pressure steam turbine
5:: steam extraction pipe
6:: heat exchanger (first heat exchanger)
7:: heater
8:: steam introduction pipe
9:: generator
10:: condenser
11:: deaerator
12:: feed-water heater
13A, 13B:: drain tank
32:: separator
33A, 33B:: heat exchanger (second heat exchanger)
34:: steam fetching pipe
71:: moisture separator
72:: steam turbine
73:: steam extraction pipe
74:: heat exchanger
75:: heater
76:: steam introduction pipe
77:: generator
78:: condenser
79:: cooling tower
W1:: production well
W2:: injection well

Claims

A moisture separation facility comprising:
a moisture separator that separates moisture from steam serving as a working fluid of a steam turbine;
a steam extraction pipe that extracts a portion of the steam whose moisture is separated from the moisture separator;

a first heat exchanger that heats the steam by performing heat exchange between the steam extracted from the moisture separator through the steam extraction pipe and a heating medium;

a heater that heats the heating medium; and

a steam introduction pipe that introduces the steam heated by the heat exchanger into the steam turbine as a working fluid,

wherein the steam turbine is operated by the steam whose moisture is separated in the moisture separator, and the steam heated by the heat exchanger.
The moisture separation facility according to Claim 1,
wherein the moisture separator includes a cylindrical container, a separator that separates the moisture from the steam serving as the working fluid introduced into the container, a second heat exchanger that heats the steam whose moisture is separated by the separator, and a steam fetching pipe that is disposed between the separator and the second heat exchanger so as to acquire a portion of the steam whose moisture is separated by the separator, and
wherein the steam fetching pipe communicates with the steam extraction pipe.
The moisture separation facility according to Claim 1 or 2,
wherein the heater heats the heating medium by using a system external heat source.
The moisture separation facility according to Claim 2 or 3,
wherein the second heat exchanger heats the steam whose moisture is separated by the separator by using a system internal heat source.
A power plant comprising:
a steam generator;

a high-pressure steam turbine operated by steam generated in the steam generator;

a moisture separator that separates moisture from the steam discharged from the high-pressure steam turbine;

a low-pressure steam turbine operated by the steam whose moisture is separated in the moisture separator;

a steam extraction pipe that extracts a portion of the steam whose moisture is separated from the moisture separator;

a first heat exchanger that heats the steam by performing heat exchange between the steam extracted from the moisture separator through the steam extraction pipe and a heating medium;

a heater that heats the heating medium;

a steam introduction pipe that introduces the steam heated by the heat exchanger into the low-pressure steam turbine as a working fluid;

a generator driven by the high-pressure steam turbine and the low-pressure steam turbine; and

a condenser that condenses the steam discharged from the low-pressure steam turbine.
The power plant according to Claim 5,
wherein the moisture separator includes a cylindrical container, a separator that separates the moisture from the steam serving as the working fluid introduced into the container, a second heat exchanger that heats the steam whose moisture is separated by the separator, and a steam fetching pipe that is disposed between the separator and the second heat exchanger so as to acquire a portion of the steam whose moisture is separated by the separator, and
wherein the steam fetching pipe communicates with the steam extraction pipe.
The power plant according to Claim 5 or 6,
wherein the heater heats the heating medium by using a system external heat source.
The power plant according to Claim 6 or 7,
wherein the second heat exchanger heats the steam whose moisture is separated by the separator by using a system internal heat source.
A power plant comprising:
a moisture separator that separates moisture from steam generated by geothermal heat;

a steam turbine operated by the steam whose moisture is separated in the moisture separator;

a steam extraction pipe that extracts a portion of the steam whose moisture is separated from the moisture separator;

a heat exchanger that heats the steam by performing heat exchange between the steam extracted from the moisture separator through the steam extraction pipe and a heating medium;

a heater that heats the heating medium;

a steam introduction pipe that introduces the steam heated by the heat exchanger into the steam turbine as a working fluid;

a generator driven by the steam turbine; and

a condenser that condenses the steam discharged from the steam turbine.
The power plant according to Claim 9,
wherein the heater heats the heating medium by using a system external heat source.
A method for operating a steam turbine, comprising:
a step of separating moisture from steam inside a moisture separator;

a step of extracting a portion of the steam whose moisture is separated from the moisture separator;

a step of heating the steam by performing heat exchange between the steam extracted from the moisture separator and a heating medium; and

a step of introducing the steam whose moisture is separated in the moisture separator and the steam heated by the heat exchange with the heating medium into a steam turbine as a working fluid.