EP2923149A2

EP2923149A2 - Draining a power plant

Info

Publication number: EP2923149A2
Application number: EP13799059.4A
Authority: EP
Inventors: Erich Schmid; Michael SCHÖTTLER; Anja Wallmann
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2012-12-19
Filing date: 2013-12-03
Publication date: 2015-09-30
Anticipated expiration: 2033-12-03
Also published as: ES2781836T3; EP2923149B1; US9719676B2; WO2014095337A3; US20150323176A1; WO2014095337A2; EP2746656A1

Abstract

The invention relates to a power plant (1), particularly a coupled gas and steam power plant (1), comprising a plurality of first drainage lines (11) that are fluidically connected on the upstream side to a water-steam circuit (2) and are fluidically connected on the downstream side to an overpressure vessel (20). Additionally, at least one steam-conducting supply line (12), via which steam can be fed back to the water-steam circuit (2), is fluidically connected to the overpressure vessel (20). The invention further relates to a method for operating such a power plant, wherein the at least one steam-conducting supply line (12) can supply steam to the water-steam circuit (2) in the region of a low-pressure stage (7), particularly in the region of the steam drum (8) of the low-pressure stage (7).

Description

description

The present invention relates to a power plant, in particular a coupled gas and steam power plant, which has a number of drainage pipes for dewatering a water-steam cycle, and a method for operating such a power plant.

Steam-powered power plants, in particular coupled gas and steam power plants, have a water-steam cycle, which can sometimes be designed as one or more circulating steam generator with steam drums and the associated heating surfaces. Such circulating steam generators are usually subdivided into a high-pressure stage, a medium-pressure stage and a low-pressure stage, depending on their working pressure regime. Within individual pressure stages of the water-steam cycle, by absorbing thermal energy, steam (hereinafter referred to simply as steam) is generated which can be supplied to one or more steam turbines for generating electric energy. Instead of circulating steam generators of the power plant, the steam generator can also be designed as a forced-circulation steam generator (Benson boiler, Sulzer boiler, etc.). However, such circulating steam generators are usually provided only in the high-pressure stage of the water-steam cycle, but can in principle also be provided for the lower pressure stages. Due to numerous chemical and physical processes fall in the water-steam cycle during operation of the power plant more or less heavily contaminated wastewater. In order not to impair the readiness of the power plant during operation by these impurities, it is necessary to drain the power plant and thus remove the impurities or wastewater from the water-steam cycle. Such drainage is typically during ongoing operation of the Power plant made. In this case, the drains are discharged from normally closed in regular operation lines in which the wastewater has accumulated. For removal, the relevant lines are opened for a short time and the drains are drained off. During the drainage, the water-steam circuit is thus lost water, which must be supplied again by additional water, so-called deionized, the water-steam cycle. In addition, in the pipes of the water-steam

Circulation also condensation water, which precludes an efficient use of the water-steam cycle. Such condensation water forms, in particular, due to time-varying operating conditions in the water-steam cycle. Condensation falls so, for example, when you shut down the power plants in the water-steam cycle, since at decreasing operating temperatures, the vapor contained in the water-steam cycle condenses increasingly condensed and the resulting condensed water also accumulates in parts of the system, for a longer Contact with liquid water are not provided. In this respect, when powering down a power plant, it is necessary to remove more water from the water-steam circuit in order to avoid unwanted condensation of water in unscheduled plant parts. At the same time less water is refilled in the water-steam circuit when driving down to keep at the end of the Abfahrprozesses relevant plant components largely free of condensed water. In order to remove such condensation water from the water-steam

To remove cycle, one also uses suitable drainage pipes, which are fluidly connected to the water-steam cycle. Sometimes these are identical to the drainage pipes for the discharge of contaminated waste water from the water-steam cycle.

It should be noted at this point that, in the context of the present invention, drainage of the power station Anläge both polluted wastewater, as well

Sludge, as well as condensed water, which has accumulated in unintended areas of the water-steam cycle.

According to the prior art, it is already known to collect drainages from different parts of the water-steam circuit, in particular from different pressure stages, and to guide them together. In this case, the drainages, as described, for example, in WO 2006/058845 (US 2008 0104959 A1) or US 2007 0289304 A1, can be temporarily stored in a tank for further processing.

A disadvantage of these solutions of the prior art, however, is that the temporary storage of the drainage, the thermal energy contained therein can not be made usable. Rather, the thermal energy is discharged unused in discarding the drainage into the environment from the power plant. In addition, it turns out to be disadvantageous that introduced into the water-steam cycle to replace the drains drained additional water must be re-processed thermally to be raised to a temperature level, which already in the water-steam cycle existing water or sufficiently close. This, in turn, requires the expenditure of thermal energy and makes the energy balance of the power plant unfavorable. In addition, it proves to be disadvantageous that the drained from the water-steam circuit drainages must be prepared in an energetically complex process, in particular to separate the slurries of reusable as deionized water. It is particularly unfavorable in terms of the balance of resources if the treated water is no longer returned to the water-steam cycle but is discarded, for example, into the environment.

According to these disadvantages, which are known from the prior art, it turns out to be technically necessary to propose a solution for the drainage of a power plant, which avoids the disadvantages known from the prior art. In particular, the technical solution to be proposed is intended to enable an energetically advantageous use of the energy extracted by the discharge of dehydrations from the water-steam cycle. In other words, it should be made with respect to the overall energy balance of the power plant operation improved drainage. Moreover, it is desirable to make available again the energy dissipated from the water-steam cycle and the drainages for the power plant and in particular for the water-steam cycle.

These objects of the present invention are achieved by a power plant according to claim 1 and by a method for operating such a power plant according to claim 13.

In particular, these objects of the invention are achieved by a power plant, in particular a coupled gas and steam power plant, comprising a number of first drainage pipes, which

upstream with a pressure stages having water-steam circuit are fluidly connected, and which are fluidly connected at the downstream side with an overpressure container, further at least one steam supply line leading to the fluid pressure tank is fluid technically connected via which steam the water vapor - Circuit can be supplied again, wherein the at least one steam leading supply line can supply the water-steam cycle in the region of a low-pressure stage, in particular in the region of the steam drum of the low pressure stage steam.

Furthermore, the objects underlying the invention are achieved by a method for operating a power plant as described above and below, comprising the following steps: Dewatering water and / or steam from a water-steam cycle by supplying to a pressure vessel;

Returning steam from the pressure vessel to the water-steam cycle in the region of a low-pressure stage, in particular in the region of the steam drum of the low-pressure stage.

The idea of the invention teaches the dehydration of the water-steam cycle by means of a number of first drainage pipes, which are fluidly connected upstream with the water-steam cycle. When draining the drainage via these drainage pipes, the first drains are introduced into a pressure vessel in which a relaxation to a relatively lower

Pressure level can be adjusted in comparison to the pressure level of the water-steam cycle. However, the pressure vessel further has a pressure level which is above the ambient pressure level. In this respect, there is an overpressure level in it. During the relaxation, on the one hand, there is a reduction in the temperature level of the introduced dehydration and, preferably, at least a partial evaporation of the liquid dehydration. The steam in the overpressure container, which furthermore has usable thermal energy, is again supplied to the water-steam cycle for further use via the supply line which is fluidly connected to the overpressure container. This is in particular unproblematic, since this steam contains no impurities and can thus be returned to the water-steam cycle in "purified" form During the expansion in the overpressure container, the impurities remain largely or even substantially completely in the liquid phase, ie liquid water.

According to the invention it is further provided that the at least one steam leading supply line the water-steam cycle in the region of a low-pressure stage, in particular in the field the steam drum of the low pressure stage can supply steam. The term "in the field" is to be understood in the sense of "in the local area", as will be explained below. According to the embodiment, the connection is made, in particular, with the low-pressure stage, in particular the steam drum of the low-pressure stage. Due to the prevailing in the low pressure stage relatively lower pressure levels, a transfer of steam from the pressure vessel in the water-steam cycle is energetically particularly favorable. In particular, it is conceivable that the pressure level of the vapor in the pressure vessel is not substantially below the pressure level of the low pressure stage or even at the same pressure level or above. In this respect, the low-pressure stage is suitable for printing, and thus energy technology for returning the discharged from the pressure vessel vapor particularly.

It thus turns out to be advantageous that the thermal energy contained in the recirculated steam can again be available for power generation in the water-steam circuit of the power plant. Furthermore, this back the water-steam cycle recycled steam saves the use of additional make-up water, which in turn would be reprocessed before it could be fed to the water-steam cycle.

Furthermore, it is advantageous that the accumulation of dehydration and of steam, which must be supplied to the environment, can be drastically reduced in terms of quantity. As a result, the sometimes relatively strict regulatory requirements and environmental regulations can be met more easily.

In addition, as already indicated, the addition of additional water (deionate) to replace the drained drains significantly reduced, whereby the necessary desalination for the deionized cost and energy technology can be advantageously reduced. Compared to the normal operation known from the prior art, a power plant with the present invention can thus be operated both economically and environmentally friendly and thus with higher efficiency.

At this point, it should again be noted that the term of steam in the sense of vaporous water should be understood, as it occurs, for example, in the water-steam cycle. The quality of the water, for example, due to an alternating content of various impurities, should have no influence on the conceptual meaning. Similarly, the term of the water should include wastewater as well as in the water-steam cycle remaining useful water or condensation water. The same applies to the steam discharged from the water-steam cycle as well as to the useful steam remaining in the water-steam cycle. In this respect, according to the case, the concept of water or steam can also be equated with the concept of drainage.

According to the embodiment, it is also possible for the number of first drainage pipes to be "one", ie according to the invention the power plant comprises only one drainage pipe According to a first preferred embodiment of the power plant according to the invention, it is provided that the number of first drainage lines upstream with the water-steam cycle in the region of a high-pressure and / or medium-pressure stage, in particular in the region of a steam drum of high-pressure A fluid-technical interconnection "in the area" means in local proximity, wherein a fluid-technical interaction is brought about. In particular, According to the interconnection with the high-pressure and / or the medium-pressure stage, or the steam drum of the high-pressure and / or steam drum of the medium-pressure stage. Likewise, the interconnection can also take place with a forced-circulation steam generator of the high-pressure and / or a forced-circulation steam generator of the medium-pressure stage.

Alternatively or additionally, the number of first drainage lines upstream can also be connected to the water-steam cycle in the region of the low-pressure stage, in particular in the region of the steam drum of the low-pressure stage. Similarly, the interconnection can also with a

Forced-circulation steam generators of the low-pressure stage take place. Due to the pressure levels prevailing in the high-pressure and / or medium-pressure stage, there is an advantageous introduction, in particular an energetically advantageous introduction of the water or steam removed from the water-steam cycle into the overpressure container. There it comes to execution according to a change in the pressure level, in particular a relaxation of the steam, wherein the drained into the pressure vessel dehydration in the presence of vapor phase can be advantageously recycled back into the water-steam cycle. Due to the relatively higher

Pressure levels of the derived from the high-pressure and / or medium pressure stage steam is in particular in the pressure vessel before a relatively higher pressure level, which favors the return to the water-steam cycle energetically.

According to a further advantageous embodiment of the invention, it is provided that the power plant also has an atmospheric pressure vessel, which enables a Dampfentspan- voltage to substantially atmospheric pressure, and which is line technology connected to the pressure vessel so that steam from the pressure vessel are passed into the atmospheric pressure vessel can. The atmospheric pressure vessel and the pressure vessel are thus to Collection of drainages ready. The drains are passed in vapor phase from the pressure vessel into the atmospheric pressure vessel, wherein the pressure vessel can be converted to a correspondingly lower pressure level. Thus, the atmospheric pressure vessel serves on the one hand to accumulate dehydration and at the same time also to regulate the pressure of the pressure in the pressure vessel. Furthermore, the atmospheric pressure container allows a suitable drainage of the drainage systems without the pressure vessel having to be subjected to changes in terms of printing technology, for example during operation. For example, it is possible to discharge condensed drainages from the atmospheric pressure container into the environment, this happening at a point in time when the atmospheric pressure container and the overpressure container are not interconnected in any fluid connection. According to the invention, relaxation to substantially atmospheric pressure level should include a pressure level corresponding to the atmospheric pressure level with a pressure tolerance of up to 20%.

Furthermore, it is also possible that adjusting means of the

Power plant are included, which are adapted to set the amount of steam, which can be passed from the pressure vessel into the atmospheric pressure vessel. In particular, the adjusting means between the pressure vessel and atmospheric pressure vessel is connected by line technology. Correspondingly, when the condensed drains located in the atmospheric pressure container are discharged, the actuating means can interrupt the fluid connection between the overpressure container and the drainage container, so that removal from the atmospheric pressure container can be carried out without further influence with respect to the change of the pressure level in the overpressure container. According to a further advantageous embodiment of the invention, it is provided that a number of second drainage lines is connected, which are connected upstream with the water-steam cycle, and which downstream side are connected to the atmospheric pressure vessel, and via which water and steam from the water-steam cycle can be fed to the atmospheric pressure vessel. According to the embodiment, water and steam from the water-steam cycle, which is in particular at a relatively low pressure level, can thus be transferred into the atmospheric pressure tank. It may also prove advantageous, according to the embodiment, to transfer dehydrations from the water-steam circuit into the atmospheric pressure vessel if the dewatering collected therein is to be subjected to a different treatment form than the dehydration collected in the overpressure vessel.

In accordance with the practice, it is further possible for the number of second drainage conduits to be "one", i.e. according to the invention the power plant comprises only a second drainage conduit.

According to a particularly advantageous continuation of this idea, it is provided that the number of second drainage lines is connected upstream to the water-steam cycle in the region of the low-pressure stage. As already stated above, the term "in the range" in a local area means that, in particular, the connection is made with the low-pressure stage The pressure level in the low-pressure stage is sometimes sufficiently low to transfer steam into the atmospheric pressure vessel, which is not energy-efficient In this respect, it seems advantageous to supply the drains discharged from the high-pressure and / or medium-pressure stage to the overpressure container, whereas the liquid drains discharged from the low-pressure stage preferably provide for a rejection into the environment Vapor drains discharged from the low-pressure stage can preferably likewise be supplied to the overpressure container, as already explained above. According to a further advantageous aspect of the invention, it is provided that the atmospheric pressure container is connected to a recirculation line, which makes it possible to supply water from the atmospheric pressure container to a first cooling source, and to recycle the thus thermally treated water back into the atmospheric pressure container. The recirculation of water from the atmospheric pressure vessel allows the prevention of steam formation in the atmospheric pressure vessel.

According to a further embodiment of the power plant according to the invention, the overpressure container and / or the atmospheric pressure container is line-connected with a second cold source, which makes it possible to thermally treat water discharged from the overpressure container and / or the atmospheric pressure container. In this respect, for example, the drains discharged from the pressure vessel or the atmospheric pressure vessel can be cooled before further processing or separation and cleaning. This cooling is known to most of the prior art

Purification process or treatment process required. This cooling can in turn be done by means of water from the main capacitor of the power plant or water from an intermediate cooling to provide the second source of cold. The water thus treated can, according to the embodiment, again be provided for recycling into the water-steam cycle as a deionate.

According to a further embodiment of the invention, it is provided that the overpressure container and / or the atmospheric pressure container is line-connected to a collecting container, in which water located in the overpressure container and / or in the atmospheric pressure container can be transferred for storage. The collecting container is capable in particular of the collection of condensed drainages and allows the merging of these before, for example, a further cleaning and treatment of these drains can take place. The merger presents be as process technology as well as energetically particularly useful and advantageous.

According to a further development of this embodiment according to the invention, provision is made for the collecting container to be connected to a processing unit in terms of line technology, wherein the processing unit can at least partially clean the water of impurities. After cleaning the water present as drainage by means of the treatment unit, the recycled water can be added to the water-steam

Recycle be re-supplied as make-up water (deionized).

According to a continuation of this idea, it is also possible that the collecting container and / or the treatment unit is connected in terms of line technology with the main capacitor of the power plant such that water from this the

Main capacitor can be supplied. As in the entire application, the main capacitor corresponds to the capacitor in which the steam is condensed, which is fed to the steam turbine or steam turbines for power generation.

The invention will be explained in more detail below with reference to individual figures. In this case, the features with the same technical effect preferably have the same reference numerals.

It should also be pointed out that the figures are merely a schematic representation of the idea of the invention, which represents no restriction as to the feasibility of the invention.

Furthermore, the individual features shown in the following figures are claimed in isolation as well as in any combination with other features as far as they fall under the present invention idea.

Hereby shows: Figure 1 is a schematic representation of an embodiment of the power plant according to the invention; FIG. 2 shows a flow chart representation of an embodiment of the method according to the invention for operating a power plant installation;

FIG. 1 shows a possible embodiment of the present power plant 1 according to the invention, which has a water-steam circuit 2. According to the embodiment, the water-steam circuit 2 is comprised by the steam part of a gas and steam power plant 1. Here, the water-steam cycle 2 a total of three different pressure levels 3, 5, 7, the

Serve steam preparation. The steam processed in these pressure stages 3, 5, 7 is supplied to a steam turbine 90 (or a plurality of steam turbines 90) for power generation, which is connected in a fluidic manner to a main capacitor 100 as a cold source. Likewise, it is possible for the steam prepared in the pressure stages 3, 5, 7 to be led to the main condenser 100 via condensation diverter stations not provided with reference numerals.

In order to supply the resulting in a start-up or shutdown or normal operation or in standstill operation of the power plant 1 drainages in the respective pressure levels 3, 5, 7, a cleaning or recycling according to the invention in the water-steam cycle 2, sees the power plant 1 before a number of first drainage pipes 11, which allow the extracted from the pressure stages 3, 5, 7 drains forward a pressure vessel 20. In this case, the first drainage lines 11 are fluidically connected upstream with corresponding line sections of the respective pressure stage 3, 5, 7. In particular, the first drainage pipes 11

upstream of the steam drum 4 of the high-pressure stage 3 fluidly connected or the steam drum 6 of the medium-pressure stage 5. Alternatively, the first Entwäs- serungsleitungen 11 upstream fluidly connected to a not further shown flange of a forced once-through steam generator of the high-pressure stage 3 or connected to a not shown flange of a forced-flow steam generator of the intermediate pressure stage 5. Likewise, there is a possible interconnection with steam drum 8 of the low-pressure stage 7, to which, however, according to the embodiment can be dispensed with. According to another advantageous embodiment, this latter first drainage line 11 is not provided for the discharge of drains from the low pressure stage 7 in the pressure vessel 20.

After initiation of the dehydration in the pressure vessel 20 is a separation into vapor and liquid fractions of the dehydration, wherein the vaporous components can be advantageously recycled back into the water-steam cycle 2. Since the steam is not present in contaminated form, can thus easily be provided without further purification of the water-steam cycle treated water / steam. For this purpose, a feed line 12 is fluidically connected to the overpressure container 20, which is connected downstream of the steam drum 8 of the low-pressure stage 7. This makes it possible, located in the pressure vessel 20 steam, compared to the high pressure stage 3 and medium pressure stage 5 at a lower

Supplied pressure level operated low-pressure stage 7, wherein the thus returned steam for electric power generation by means of the turbine 90 (steam turbine) may be available again. In this case, the turbine 90 can likewise be designed as a number of individual turbines which are suitably connected to the respective pressure stages 3, 5, 7.

Furthermore, the power plant 1 comprises an atmospheric pressure tank 30, which is also fluidly connected to the pressure tank 20. In the line provided between the overpressure container 20 and the atmospheric pressure container 30 for connection, an adjusting means 25 is also provided, which allows to interrupt the fluid connection or the Adjust fluid flow suitable. Thus, it is possible to transfer the steam present in the overpressure container 20 to the atmospheric pressure container 30 during operation. Thus, on the one hand, the pressure level in the pressure vessel 20 can be suitably adjusted, and on the other hand, the costs incurred in the atmospheric pressure vessel 30 drainages can be suitably dissipated without having to change the pressure level in the pressure vessel 20 at the same time. Thus, according to the embodiment, a discharge line 35 is provided, via which, in particular, vaporous water can be supplied from the atmospheric pressure container 30 to the environment U.

For dewatering the working at a relatively lower pressure level low-pressure stage 7 second drainage serungsleitungen 13 are also provided, which allow a transfer of incurred in the low-pressure stage 7 dewatering into the atmospheric pressure vessel 30.

In order to prepare the dehydrations incurred in the overpressure container 20 as well as the atmospheric pressure container 30, in particular in liquid form, for further use in the water-steam circuit 2, they can be diverted into a collecting container 70. For thermal conditioning, in particular for cooling these drainages before introduction into the collecting container 70, according to the invention a first cold source 50 as well as a second cold source 60 are provided.

In addition, the power plant 1 sees a

Recirculation line 40, which drainages can be seen from the atmospheric pressure tank 30 to supply the first source of cold 50. Thereafter, the so thermally conditioned dehydrations are completely or partially recycled to the atmospheric pressure vessel 30, but at a lower temperature level. This temperature treatment allows the reduction of an undesirable

Swathing in the atmospheric pressure vessel 30 as the vapor is condensed. FIG. 2 shows a flow chart representation of an embodiment of the method according to the invention for operating a power plant. Here are the following

Steps includes:

Dewatering water and / or steam from a water-steam cycle (2) by supplying to an overpressure container (20) (first method step 200);

Returning steam from the overpressure container (20) to the water-steam circuit (2) in the region of a low pressure stage (7), in particular in the region of a Dampftrom- mel (8) of the low pressure stage (7) (second method step 210).

Further embodiments emerge from the subclaims.

Claims

claims

1. Power plant (1), in particular a coupled gas and steam power plant (1), comprising a number of first drainage pipes (11), which upstream with a plurality of pressure stages (3, 5, 7) having water-steam cycle ( 2) are fluidically interconnected, and which are connected downstream of a fluid pressure tank (20), wherein further at least one steam supply line (12) with the pressure vessel (20) is fluidly connected, via which steam the water-steam cycle (2) can be fed again

d a d u r c h e s e n c i n e s, d a s s

the at least one steam-carrying supply line (12) can supply steam to the water-steam cycle (2) in the region of a low-pressure stage (7), in particular in the region of a steam drum (8) of the low-pressure stage (7).

2. Power plant according to claim 1,

d a d u r c h e s e n c i n e s, d a s s

the number of first drainage pipes (11)

upstream with the water-steam cycle (2) in the high-pressure (3) and / or medium-pressure stage (5) are connected.

3. Power plant according to one of claims 1 or 2, d a d u c h e c e n e c i n e t, d a s s

the number of first drainage pipes (11)

upstream with the water-steam cycle (2) are connected in the Nierdruckstufe.

4. Power plant according to one of the preceding claims,

d a d u r c h e s e n c i n e s, d a s s

the power plant (1) further comprises an atmospheric pressure vessel (30), which enables a DampfentSpannung to substantially atmospheric pressure, and which is so wired with the pressure vessel (20), that steam from the pressure vessel (20) in the atmospheric pressure vessel (30) can be passed.

5. Power plant according to claim 4,

d a d u r c h e s e n c i n e s, d a s s

Furthermore, an adjusting means (25) of the power plant (1) is included, which is adapted to adjust the amount of steam which can be passed from the pressure vessel (20) in the atmospheric pressure vessel (30).

6. Power plant according to one of the preceding claims 4 or 5,

d a d u r c h e s e n c i n e s, d a s s

a number of second drainage conduits (12) are connected upstream of the water-steam circuit (2) and which are connected downstream of the atmospheric pressure tank (30) and via which water and / or steam from the water Steam cycle (2) the atmospheric pressure vessel (30) can be fed.

7. Power plant according to claim 6,

d a d u r c h e s e n c i n e s, d a s s

the number of second drainage pipes (13)

upstream with the water-steam cycle (2) in the region of the low-pressure stage (7) is connected.

8. Power plant according to one of the preceding claims 4 to 7,

d a d u r c h e s e n c i n e s, d a s s

the atmospheric pressure container (30) with a

Recirculation line (40) is connected, which allows to supply water from the atmospheric pressure tank (30) of a first cooling source (50), and the thus thermally treated water leads back into the atmospheric pressure tank (30).

9. Power plant according to one of the preceding claims, characterized in that

the overpressure container (20) and / or the atmospheric pressure container (30) is conductively connected to a second cold source (60) which makes it possible to thermally treat water discharged from the overpressure container (20) and / or the atmospheric pressure container (30).

10. Power plant according to one of the preceding claims,

d a d u r c h e s e n c i n e s, d a s s

the overpressure container (20) and / or the atmospheric pressure container (30) is line-connected with a collecting container (70) in which water located in the overpressure container (20) and / or the atmospheric pressure container (30) can be transferred for storage.

11. Power plant according to claim 10,

d a d u r c h e s e n c i n e s, d a s s

the collecting container (70) is conductively connected to a processing unit, wherein the processing unit can at least partially clean the water from impurities.

12. Power plant according to claim 10 or 11,

d a d u r c h e s e n c i n e s, d a s s

the collecting container (70) and / or the treatment unit is line-connected with the main capacitor (100) of the power plant (1) in such a way that water can be supplied from this to the main capacitor (100).

13. A method for operating a power plant (1) according to the preceding claims, comprising the following steps:

Dewatering water and / or steam from a water-steam cycle (2) by supplying to an overpressure container (20);

Returning steam from the overpressure container (20) to the water-steam cycle (2) in the region of a derdruckstufe (7), in particular in the region of a steam drum (8) of the low-pressure stage (7).