EP1377730B1 - Steam power plant provided with a retrofit kit and method for retrofitting a steam power plant - Google Patents

Description

Technical area

The invention relates to a steam power plant with retrofit kit and a method for retrofitting a steam power plant.

State of the art

Power plants with conventional water / steam cycle are known from the prior art. Known steam turbine plants are formed by a steam turbine set including condensation plant, connecting pipes and auxiliary equipment. The steam turbine set usually consists of multi-stage steam turbines. About the steam turbo set a work machine is driven, which is formed in the case of a power plant by a generator. Large, fossil-fueled steam turbine plants typically use a reheat process.

Such a steam power plant with reheat is schematically in FIG. 7 shown. In a steam boiler 1 including superheater 2 while condensate or boiler feed water is heated to the desired steam temperature. The live steam temperature is usually about 520 ° C to 565 ° C, the live steam pressure is about 120 bar to 200 bar. About steam valves 3, the steam enters a high-pressure turbine 4. Here, the pressure drop is converted into mechanical energy, before the steam at the outlet into a stream, the one High-pressure feedwater pre-heater 21 is supplied, and a stream which is supplied to a reheater 5, is divided. The steam supplied to the high pressure feedwater pre-heater 21 is also referred to as bleed steam for feedwater pre-heating and serves to heat the feedwater by means of heat exchangers. The second partial flow passes, as already mentioned, via a reheater 5 and 6 interceptor valves in a medium-pressure turbine 7, wherein pressure and temperature here typically be 30 to 40 bar and 520 ° C to 565 ° C. From the medium-pressure turbine 7 also passes tap water for the feedwater preheating in high-pressure feedwater preheaters 19 and 20 or directly into a connected to a boiler feed pump 18 feedwater tank 17. The other part of the steam flow, which is also referred to as working steam, enters a low-pressure turbine 8, from where the exiting working steam flows into a condensing unit 11 designed as a condenser, in which the steam is condensed by means of a heat exchanger through which cooling water flows. The condensate is preheated by, for example, two low-pressure feedwater preheaters, here designated by reference numerals 15, 16, and fed to the feedwater tank 17 by means of a condensate pump 13. The preheating in the low-pressure feedwater preheaters 15, 16 takes place with bleed steam from the low-pressure turbine 8. There are also known steam power plants, which also take on the high-pressure turbine 4 additional bleed steam at elevated pressure for an additional Speisewasservorwärmstufe. The high-pressure turbine 4, the medium-pressure turbine 7 and the low-pressure turbine 8 are usually arranged on a common shaft 9, which is rotatably supported by shaft bearings 12. The shaft 9 drives a rotor of an alternator 10, through which the power generation is effected.

The life of such conventional steam power plants is about 40 to 50 years. However, older steam power plants achieve only a moderate degree of efficiency due to their original design and the aging of the components and therefore have an increased fuel demand, combined with increased operating costs and emissions. Therefore, many older steam power plants, despite their mechanical functionality and their far from producing reached end of the operating life cycle, uneconomical. This is particularly true due to increased competition in markets where modern plants, including combined cycle power plants, have a gas turbine cycle and a steam turbine cycle, such as those in the DE 19542917 A1 or the DE 19923210 A1 described are operated.

A currently practiced approach to avoiding such losses is a conventional retrofit of older steam power plants where only the steam path of the turbines is modified. For this purpose, new rotating and stationary turbine blades with improved profile are exchanged for the old turbine blades. As a rule, only certain blade rows are exchanged here, while the remaining blade rows continue to be operated unchanged. By this measure it is achieved that increases at substantially unchanged steam conditions, the power output of the steam power plant at the same fuel consumption. In addition, instead of a sole replacement of the turbine blades at the same time, the entire rotor including the rotating blades and / or the stator, in which the stationary blades are mounted, replaced and thus the existing steam turbine plant can be better utilized. Such a modification alone does not cause any significant major changes to the generator, the boiler, piping, capacitors or buildings. The steam temperature and the vapor pressure remain substantially unchanged in such retrofitting.

Disadvantage of this retrofit measure is that the performance and efficiency increase generally turns out to be only moderate. The improvement in efficiency, that is, the reduction of fuel consumption with unchanged electric power or the increase in electrical power with unchanged fuel consumption is too low, however, to reduce the cost per kilowatt hour and a much more attractive solution in terms of more competitive prices or The reduction of specific emissions. It follows that the competitiveness of older steam power plants can hardly be significantly increased in this way.

Although reveal the DE 19982386 A1 and the DE 19962403 A1 A method for retrofitting or converting a saturated steam generating system with at least one steam turbine group and after these processes nach- or retrofitted power plants. However, here the addition of a gas turbine kit is proposed as a supplement to the steam turbine set, which is equivalent to a restriction of the fuel supply. Furthermore, this creates a combined plant whose maintenance is more complex than in a pure steam turbo plant.

Further, the WO 98/49428 a retrofitting system for coal-fired power plants. According to the WO 98/49428 A hydrogen combustion system will be installed to reach extremely high steam temperatures from 650 ° C to 870 ° C. According to one embodiment, the power plant's high-pressure turbine is completely replaced by a retort package comprising a hydrogen combustion system and a new high-pressure turbine suitable for this purpose. The high-pressure turbine is rigidly coupled to the same shaft of the already existing downstream turbine stages. The WO 98/49428 discloses all features in the preamble of claim 1.

Closing reveals the WO 97/18386 a refitting system in which an existing power plant operating on low superheated steam is supplemented by adding a gas turbo set. In this respect corresponds to the WO 97/118386 of the DE 19962386 A1 and DE 19962403 A1 , However, it is additionally proposed here that a high-pressure super-hot-steam turbine be supplemented, which is fed by a gas turbine heated heat recovery steam generator. The inlet temperatures for the superheated steam high-pressure turbine are 537 ° C to 593 ° C and the inlet pressures 69bar to 248bar. The super hot steam weekly pressure turbine and the gas turbine thereby drive a new common generator, while the existing steam turbine set remains unchanged and drives the previous generator.

Presentation of the invention

The invention has for its object to avoid the disadvantages of the prior art described above. Furthermore, it is an object of the present invention to provide a way to improve the efficiency or to extend the life of existing steam power plants available. In this case, the most cost-effective solutions are to be created in which as much as possible original parts of the existing steam power plant can continue to be used. Furthermore, if possible, the general infrastructure should be maintained. Finally, the use of existing operating licenses often plays an important role.

This object is achieved by a steam turbine plant with retrofit kit having the features of patent claim 1 and a method for retrofitting a steam power plant having the features of patent claim 10. Advantageous embodiments and further developments of the solution according to the invention are specified in the subclaims.

An inventive steam power plant with retrofit kit has a steam generator with superheater, a steam turbine set including condensation plants, connecting pipes, auxiliary equipment and a generator. According to the invention, the retrofit kit at least one for elevated steam temperatures> 565 ° C, preferably 620 ° C to 720 ° C, and for unchanged or Modified live steam pressure designed retrofit turbine module, which is upstream of the existing steam turbine set with the shaft of the retrofit turbine module and the shaft of the existing steam turbine set are mechanically coupled together.
For this, the existing generator may need to be adapted or replaced, or the power delivered may be limited to a permissible level. Alternatively, for example, an additional generator may be added at a still free end of the shaft to reduce the excess power. The term turbine module in addition to the actual turbines and the necessary piping and valves for the corresponding temperatures and pressures to understand. Finally, the retrofit turbine module is supplied with suitable parameter-containing steam.

It may turn out to be worthwhile according to the invention that the upstream high pressure also takes over the expansion of the existing high-pressure turbine, and thereby the existing high-pressure turbine can be replaced by the high-pressure turbine of the retrofit kit. The freed by the elimination of the high-pressure turbine of the existing steam power plant space can be used advantageously for the turbine module of the retrofit kit. Furthermore, at constant or reduced pressure, it is advantageous that many existing components of the steam power plant, such as e.g. the feedwater pump and piping can continue to be used. Furthermore, it can be used e.g. also the possibility to integrate one or more additional preheating stages and thus an additional increase in efficiency can be created.

Alternatively, the live steam pressure can be modified to be ≥ 200 bar, preferably 240 bar to 375 bar. If the stress on previously existing safety margins of the existing components for a substantial pressure increase is not sufficient, a corresponding modification of the pressure-loaded components is required.

As a result, the disadvantages of the prior art are avoided and the efficiency of the existing steam power plant is significantly improved. This is noticeable, for example, in that with the same amount of fuel, a higher power output is possible, or with the same power output, a smaller amount of fuel is needed. By retaining as many original parts of the steam power plant is a cost-effective solution to increase performance made available. In addition, the general infrastructure can be maintained as far as economically and environmentally sound.

Another solution variant envisages that only the live steam temperature is increased by way of example to 720 ° C., but the live steam pressure is reduced to, for example, 100 bar. This can prove to be particularly advantageous in older steam power plants, where it depends primarily on the extension of the life. In this case can be dispensed with a reheater.

An increased live steam temperature can be realized for example by modification of the superheater or by external heat sources. As a modification of the superheater comes here, for example, the use of high temperature resistant materials as well as spatial and / or geometric changes of the superheater in question.

An advantageous development of the steam power plant with retrofit kit according to the invention provides that the turbine module of the retrofit kit is made of high-temperature resistant materials, preferably of nickel-base alloys. Such alloys are particularly suitable for high steam temperatures. Depending on the component, alloys such as IN617, IN625 or Waspaloy are suitable.

In addition, an advantageous development of the steam power plant according to the invention with retrofit kit provides that the retrofit Turblnenmodul has a single or multi-flow high-pressure turbine. Here, the present at the turbine inlet steam temperature can be about 720 ° C and the live steam pressure 375 bar. The working steam exiting the upstream (super) high-pressure turbine of the retrofit turbine module is i.d.R. provided as input steam for the high-pressure turbine of the existing turbo group.

An advantageous development of the steam power plant with retrofit kit according to the invention provides that the retrofit turbine module has a single or multi-flow super-high pressure turbine and a single or multi-flow super-medium pressure turbine. In this variant of a retrofit turbine module according to the invention, the live steam temperature present at the turbine inlet of the high-pressure turbine can be for example 620 ° C. and the live steam pressure about 240 bar. The working steam exiting the upstream super-high-pressure turbine of the retrofit turbine module is usually used as input steam for the high-pressure turbine of the existing turbo group. The inlet temperature at this high-pressure turbine can be unchanged, for example 540 ° C and the inlet pressure 150 bar. The working steam is taken in this embodiment already at higher pressure from the high-pressure turbine to be modified and reheated by another reheater, for example, to about 60 bar / 620 ° C to one of the existing medium-pressure turbine upstream turbine to be fed, which relaxes the steam on the previous entry state of the existing medium-pressure turbine. If the modification of the existing high-pressure turbine is not worthwhile, the supercharging super-high-pressure can be additionally designed for the residual expansion of the existing high-pressure turbine, with which this existing component can be removed. Regardless of whether a modified high pressure section remains between super high pressure and super medium pressure, the super high pressure and super medium pressure turbine of the retrofit turbine module may be housed in a common housing or in separate housings. When arranged in a common housing material can be saved, which contributes to a reduction in manufacturing costs. Furthermore, such an arrangement leads to additional space gain, which also cramped sites can be retrofitted accordingly.

In the steam power plant with retrofit kit according to the invention, it is advantageous if the retrofit kit also has a modified steam generator and / or superheater for generating live steam with elevated steam temperature> 565 ° C, preferably 620 ° C to 720 ° C, and with unchanged or modified steam pressure. Here, the existing steam generator and / or superheater, if this is technically possible, for example, be modified for higher steam temperatures and optionally higher vapor pressure or against a retrofit steam generator and / or superheater, for generating temperatures of> 565 ° C and optionally pressures of ≥ 200 bar is exchanged. Alternatively, another steam generator and / or superheater can be connected downstream, which can also be operated with an external heat source. Such retrofit steam generators may be partially made, for example, from nickel-based alloys.

An advantageous development of the steam power plant according to the invention provides that an additional generator or a modified or replaced generator for power reduction of the additional power generated by the retrofit turbine set is provided. This can be an additional generator on the same or a separate shaft can be added in addition to the existing generator, or the existing generator can be upgraded by modification, such as the winding, or the existing generator can be completely replaced by a new generator.

• Vorschalten eines Nachrüst-Turbinenmodule für Frischdampf mit erhöhter Dampftemperatur und unverändertem oder modifiziertem Frischdampfdruck vor den bestehenden Turbosatz

wobei die Welle des Nachrüst-Turbinenmoduls und die Welle des bestehenden Dampfturbosatzes mechanisch mit einander gekoppelt werden.

• Vorsehen eines Dampferzeugers und/oder Überhitzers zur Bereitstellung von Frischdampf mit erhöhter Dampftemperatur.

A method according to the invention for retrofitting an existing steam power plant with a steam generator with superheater, a steam turbine set including customer dosing systems, connecting pipelines, auxiliary equipment and a generator comprises the following steps:

• Upstream of a retrofit turbine module for live steam with increased steam temperature and unchanged or modified live steam pressure before the existing turbo set

wherein the shaft of the retrofit turbine module and the shaft of the existing steam turbine set are mechanically coupled to each other .

• Provision of a steam generator and / or superheater to provide live steam with increased steam temperature.

If necessary, the steam generator and / or the superheater and the feedwater pump can be retrofitted or rebuilt or added to an additional designated as a booster pump feedwater pump and the associated piping for the higher live steam pressure can be modified.

As a result, the disadvantages of the prior art are avoided and the efficiency or the life of the existing steam power plant is substantially improved. By procuring as many original parts of the steam power plant as possible, a cost-effective solution for increasing performance is made available. In addition, the general infrastructure can be maintained as far as economic and environmentally sound. The spatial arrangement can be made according to local conditions. It is advantageous if the pipelines between the steam generator and retrofit turbine module are kept as short as possible in order to limit the use of high temperature resistant materials to the most necessary degree.

• Hinzufügen, Austauschen oder Modifizieren eines Generators zur Leistungsabnahme der durch den Nachrüst-Turbosatz erzeugten Mehrleistung. Dabei kann das Hinzufügen eines zusätzlichen Generators beispielsweise durch Anbringung an ein freies Wellenende erfolgen, oder der zusätzliche Generator kann, falls anwendbar, nur mit dem getrennt aufgestellten Nachrüst-Turbosatz gekoppelt werden.

An advantageous development of the method according to the invention for retrofitting a steam power plant further comprises the following step:

• Add, replace or modify a generator to decrease the power output of the retrofit turbine kit. In this case, the addition of an additional generator, for example by attachment to a free shaft end can be done, or the additional generator can, if applicable, be coupled only with the separately installed retrofit turbine set.

Brief description of the drawings

Figur 1

ein schematisches Blockschaltbild eines Dampfkraftwerks mit Nachrüstsatz;

Figur 2

ein schematisches Blockschaltbild einer ersten erfindungsgemaßen Ausführungsform eines Dampfkraftwerks mit Nachrüstsatz:

Figur 3

ein schematisches Blockschaltbild eines Dampfkraftwerks mit Nachrüstsatz;

Figur 4

ein schematisches Blockschaltbild einer Zweiten erfindungsgemäßen Ausführungsform eines Dampfkraftwerks mit Nachrüstsatz;

Figur 5

ein schematisches Blockschaltbild einer dritten erfindungsgemäßen Ausführungsform eines Dampfkraftwerks mit Nachrüstsatz;

Figur 6

ein schematisches Blockschaltbild einer vierten erfindungsgemäßen Ausführungsform eines Dampfkraftwerks mit Nachrüstsatz;

Figur 7

ein schematisches Blockschaltbild eines konventionellen Dampfkraftwerks vom Stand der Technik.

In the following, advantageous embodiments of the invention are described in conjunction with the accompanying drawings, in which:

FIG. 1

a schematic block diagram of a steam power plant with retrofit kit;

FIG. 2

a schematic block diagram of a first embodiment according to the invention of a steam power plant with retrofit kit:

FIG. 3

a schematic block diagram of a steam power plant with retrofit kit;

FIG. 4

a schematic block diagram of a second embodiment according to the invention of a steam power plant with retrofit kit;

FIG. 5

a schematic block diagram of a third embodiment of a steam power plant with retrofit kit according to the invention;

FIG. 6

a schematic block diagram of a fourth embodiment of a steam power plant with retrofit kit according to the invention;

FIG. 7

a schematic block diagram of a conventional steam power plant of the prior art.

In the drawings, only the essential elements for understanding the invention are shown. Identical or similar components are identified by the same reference numerals

Ways to carry out the invention

FIG. 1 FIG. 12 shows a schematic block diagram of a steam power plant 22 with retrofit kit, which does not form part of the claimed invention. In a suitable for high operating temperatures and high operating pressures materials, designed as a steam boiler steam generator 1 with a superheater 32 condensate or boiler feed water is brought to the desired steam temperature. A feedwater pump designated as booster pump 29 in addition to the installation (respectively the adaptation or replacement of components 18 to 21) ensures the required pressure. Alternatively, the known from the prior art components 18 to 21 can be adapted or replaced. In order to safely transport the feed water and the steam under the increased pressure, modified pressure lines 34 between the booster pump 29 and the main steam valves 23 are also provided. The live steam temperature is in the present embodiment about 700 ° C, the live steam pressure is about 375 bar.

Via a modified live steam superheater 32 and corresponding live steam valves 23, the steam passes into a super-high-pressure turbine 24 of a retrofit turbine module 25. The super-high-pressure turbine 24 is here according to the present example FIG. 1 designed to be single-entry. The steam path of the retrofitted super-high pressure turbine 24 is made of high temperature resistant materials, namely, nickel base alloys. The inlet temperature of the live steam is about 700 ° C and the input steam pressure is about 375 bar. An economic optimization can also justify the avoidance of high temperature materials by choosing a process with only eg 620 ° C and 240 bar. The super-high pressure turbine 24 is mounted on a separate shaft 14 separately from the shaft 9 of the existing turbo group. The power generated here is tapped by an additional generator (not shown) and converted into electricity.

Via a line passes from the super-high pressure turbine 24 exiting steam directly or via the decommissioned, existing live steam valves 3 in the single-flow high-pressure turbine 4 of the existing steam power plant. The unchanged turbine inlet temperature in this example is 540 ° C and the turbine inlet pressure 150 bar.

The steam is split at the exit from the high-pressure turbine 4 into a stream which is fed to a high-pressure feedwater pre-heater 21 and a stream which is fed to a reheater 5. The steam supplied to the high pressure feedwater pre-heater 21 is also referred to as bleed steam for feedwater pre-heating and serves to heat the feedwater by means of heat exchangers.

The second partial flow passes via the reheater 5 and the interceptor valves 6 in the double-ended in this example medium-pressure turbine 7, wherein pressure and temperature here typically unchanged 36 bar and 540 ° C, for example. From the medium-pressure turbine 7 also tap-in steam for the feedwater preheating in the high-pressure feedwater preheaters 19 and 20 and directly into the feedwater tank 17. The other part of the vapor stream, which is also referred to as working steam, enters the two-flow low-pressure turbine 8, from where the exiting Working steam flows into a condenser 11 in which the steam is condensed via a heat exchanger through which cooling water flows.

The condensate is preheated by means of low-pressure spas water preheaters 15, 16 and fed to the spout water tank 17. The preheating in the low-pressure feedwater preheaters 15, 16 takes place with bleed steam from the low-pressure turbine 8.

The high-pressure turbine 4, the medium-pressure turbine 7 and the low-pressure turbine 8 form the turbo group of the already existing steam power plant. The blading of this turbo group can be replaced as needed by new blades with modified blade profile. The turbo group is arranged on the common shaft 9, which is rotatably supported by shaft bearings 12. The shaft 9 drives a rotor of an alternator 10, through which the power generation is effected.

FIG. 2 shows a schematic block diagram of an advantageous embodiment of a steam power plant 22 according to the invention with retrofit kit. According to this embodiment is also in a modified steam boiler 1 with superheater 32 condensate or Kesselspelsewasser to the desired steam temperature, for example, 700 ° C and brought by a booster pump 29 to the desired vapor pressure of eg 375 bar. Alternatively, a suitable adaptation of the feedwater pump is possible.

Via a modified live steam superheater 32 and corresponding live steam valves 23, the working steam passes into the super-high-pressure turbine 24 of the retrofit turbine module 25. The super-high-pressure turbine 24 is designed to be single-flow in the present exemplary embodiment and has a steam path made of high-temperature nickel-base alloys , The inlet temperature of the live steam is about 700 ° C and the input steam pressure is about 375 bar. An economic optimization can also justify the avoidance of high temperature materials by choosing a process with only eg 620 ° C and 240 bar. The super-high-pressure turbine 24 is made according to the embodiment FIG. 2 mounted on a shaft 14, which is connected to the shaft. 9 the already existing turbo group of the retrofitted steam power plant is connected via a coupling 28.

The steam passes directly or via the corresponding, set out of operation live steam valves 3 in the single-flow high-pressure turbine 4 of the existing steam power plant. The turbine inlet temperature is also here, as before retrofitting, e.g. 540 ° C and the turbine inlet pressure 150 bar.

The steam is split at the exit from the high pressure turbine 4 into bleed steam supplied to a high pressure feedwater pre-heater 21 and working steam supplied to a reheater 5.

The working steam passes through the reheater 5 and the interceptor valves 6 in the double-ended in this example medium-pressure turbine 7, the pressure here also unchanged, typically 36 bar and the temperature, for example. 540 ° C is. From the medium-pressure turbine 7 also tap-in steam for the feedwater preheating in the high-pressure feedwater preheaters 19 and 20 or directly into the feedwater tank 17. The working steam enters the two-flow low-pressure turbine 8, from where it flows into a condenser 11, in which the steam over a is condensed by cooling water flowing through the heat exchanger.

The condensate is preheated via low-pressure feedwater pre-heater 15, 16 and fed to the feedwater tank 17. The preheating in the low-pressure feedwater preheaters 15, 16 takes place with bleed steam from the low-pressure turbine 8.

The high-pressure turbine 4, the medium-pressure turbine 7 and the low-pressure turbine 8 form the turbo group of the already existing steam power plant. The blading of this turbo group can be replaced as needed by new blades with modified blade profile. The turbo group is arranged on the common shaft 9, which is rotatably supported by shaft bearings 12.

The shaft 9 drives in the embodiment according to FIG. 2 together with the via the clutch 28 connected to the shaft 9 super-high-pressure turbine 24 to the alternator 10. The generator 10 is optionally modified so that it can absorb the power increased by connecting the super high-pressure turbine 24, or the output power is limited to a permissible level.

FIG. 3 shows a schematic block diagram of a steam power plant 22 with retrofit kit, which is not part of the claimed invention. According to this example, condensate or Kesseispelsewasser is brought to the desired steam temperature of, for example, 620 ° C and by the booster pump 29 to the desired vapor pressure of eg 240 bar in a modified for the elevated temperatures and pressures steam boiler 1 with superheater increased pressure line 34 is modified accordingly.

Via a live steam superheater 32 and corresponding live steam valves 23, the steam passes into a retrofit turbine module 25, which in the present Ausführungsbalspiel after FIG. 3 a super-pressure turbine 24 and a super medium-pressure turbine 27 has. The super-Hochdrucldurbine 24 and the Super Mitteldruckturblne 27 are each designed einflutig and arranged in a common housing. The steam pond of the retrofitted super high pressure turbine 24 and the steam path of the retrofitted super medium pressure turbine 27 are made of high temperature resistant materials.

The inlet temperature of the live steam is in the present example after FIG. 3 for example, 620 ° C and the input steam pressure eg 240 bar. The super-high-pressure turbine 24 and the super-Mllteldruckturbine 27 are mounted on a common shaft 14, separate from the shaft 9 of the existing turbo group The power generated here is tapped by an additional generator 30 and converted into electricity.

Via a reheater 31 and interceptor valves 26, the working steam from the super-high-pressure turbine 24 then enters the super-mid-pressure turbine 27 of the retrofit turbine module 25. The turbine inlet temperature of the working steam is here also e.g. 620 ° C and the turbine inlet pressure about 60 bar.

At the outlet of the super-Mitteldruckturbine 27 of the working steam is passed directly or via the existing, out-of-service interception valves 6 in the example doubly executed medium-pressure turbine 7 of the existing steam turbine module, the pressure here, for example, unchanged 36 bar and the temperature 540 ° C is. The working steam passes from the medium-pressure turbine 7 into the low-pressure turbine 8, which has a double flow in this exemplary embodiment.

The bleed steam for feedwater heating, which serves to heat the feedwater by means of a heat exchanger, and the return of the condensate in the boiler are in FIG. 3 only hinted.

The original high pressure turbine is replaced in this embodiment by the retrofit turbine module 25, which includes a super high pressure turbine 24 and a super medium pressure turbine 27. The medium-pressure turbine 7 and the low-pressure turbine 8 thereby form the turbo group of the already existing steam power plant. The blading of this turbo group can be replaced as needed by new blades with modified blade profile. The existing turbo group is arranged on a common shaft 9, which is rotatably supported by shaft bearings 12. The shaft 9 drives in the embodiment according to FIG. 3 the original three-phase generator 10 of the existing steam power plant.

FIG. 4 shows a schematic block diagram of a second advantageous embodiment of a steam power plant 22 according to the invention with retrofit kit. According to this embodiment, in a steam boiler 1 modified for the elevated temperatures and pressures, condensate or boiler feed water is likewise heated to the desired steam temperature of, for example, 620 ° C. and by the booster pump 29 or by suitable adaptation of the feedwater pump brought to the desired vapor pressure of eg 240 bar. The working at elevated pressure line 34 is modified accordingly

Via a modified live steam superheater 32 and corresponding live steam valves 23, the steam passes into a retrofit turbine module 25, which in the present exemplary embodiment has a super-high-pressure turbine 24 and a super-mid-pressure turbine 27. The super-high-pressure turbine 24 is designed to be single-flow, the super-mid-pressure turbine 27 double-flow. The steam path of the retrofitted super-high pressure turbine 24 and the steam path of the retrofitted medium pressure turbine 27 are made of high temperature resistant materials. The input temperature of the live steam in the present embodiment is, for example, 620 ° C and the input steam pressure is e.g. 240 bar. The super-high-pressure turbine 24 and the super-mid-pressure turbine 27 are mounted on a common shaft 14, which is connected to the shaft 9 of the existing turbo group via a coupling 28.

The working steam passes directly or via the existing, put out of operation live steam valves 3 in the single-flow high-pressure turbine 4 of the existing steam power plant. The turbine inlet temperature of the working steam is unchanged here 540 ° C and the turbine inlet pressure, for example, 150 bar. The existing high-pressure turbine must be rebuilt in such a way that the steam can be removed at the pressure required for the increased reheater pressure. Via a reheater 33 and intercept valves 26, the working steam enters the super-Mitteldruckturbine 27 of the retrofit turbine module 25. The Turbirieneintrittstemperatur here after reheating, for example, again 620 ° C and the turbine inlet pressure, for example, 60 bar. At the outlet of the super-Mitteldruckturbine 27 of the working steam is passed directly or via the out of service set interceptor valves 6 in the two-flow medium-pressure turbine 7, the pressure here is unchanged 36 bar and the temperature is 540 ° C. The working steam passes from the medium-pressure turbine 7 into the double-flow low-pressure turbine 8.

The bleed steam for feedwater heating, which serves to heat the feedwater by means of a heat exchanger, and the return of the condensate in the boiler are in FIG. 4 only hinted.

The due to the higher discharge pressure to be modified high-pressure turbine 4, the medium-pressure turbine 7 and the low-pressure turbine 8 thereby form the turbo group of the existing steam power plant. The blading of this turbo group can be replaced as needed by new blades with modified blade profile. The turbo group is arranged on the common shaft 9, which is rotatably supported by shaft bearings 12. The shaft 9 drives in the embodiment according to FIG. 4 together with the connected via the coupling 28 with the shaft 9 retrofit turbine set 25 to the alternator 10. The generator 10 is optionally modified so that it can absorb the power increased by connecting the retrofit turbine set, or the output power is limited to an acceptable level.

FIG. 5 shows a schematic block diagram of a third advantageous embodiment of a steam power plant 22 according to the invention with retrofit kit. In a modified for high operating temperatures superheater 32, the steam is brought to pass through the steam generator 1 to the desired steam temperature. The live steam temperature is in the present embodiment about 700 ° C, the live steam pressure remains unchanged, for example, 150 bar.

After passing through the live steam superheater 32 and corresponding live steam valves 23, the steam enters a super high pressure turbine 24 of a retrofit turbine module 25. The super high pressure turbine 24 completely replaces the high pressure turbine of the existing power plant and is via a clutch 28 with the shaft 9 of the existing steam Turbolo group connected.

The steam passes at the outlet from the super-high-pressure turbine 24 via a reheater 5 and the interceptor valves 6 in the medium-pressure turbine 7, wherein Pressure and temperature here typically 36 bar and 540 ° C, for example. From the medium-pressure turbine 7 steam enters the double-flow low-pressure turbine 8, from where the exiting working steam flows into a condenser 11, in which the steam is condensed via a heat exchanger through which cooling water flows.

Also in this embodiment, the additional power can be tapped via a modified generator 10.

Finally shows FIG. 6 a schematic block diagram of a fourth advantageous embodiment of a steam power plant 22 according to the invention with retrofit kit. This variant is provided for high operating temperatures by about 720 ° C but low operating pressures of about 100 bar, which is why essentially the original components of the existing steam power plant can be maintained and no major conversion of the steam boiler 1 is required. Also, the existing boiler feed pump 18 can operate at reduced pressure. Essentially, only a modified superheater 32 and the super high pressure turbine 24 are needed. The super-high-pressure turbine 24 replaces completely the high-pressure turbine of the existing power plant and is connected to the shaft 9 of the existing steam turbo group via a coupling 28.

Via the modified live steam superheater 32 and corresponding live steam valves 23, the steam enters the super high pressure turbine 24 of the retrofit turbine module 25.

The steam passes at the outlet from the super-high-pressure turbine 24 directly or via the shut-off valves 6 set in the medium-pressure turbine 7, wherein pressure and temperature here typically 36 bar and 540 ° C, for example. A reheater can be omitted here. Steam is supplied to the low-pressure turbine 8 from the medium-pressure turbine 7. The power is delivered to the original generator 10 connected to the shaft 9.

This fourth embodiment is particularly suitable for further operation of steam power plants beyond their actual service life at low investment costs. Since the material fatigue here only allows pressures below the original design pressures on the high pressure side, the vapor pressures acting on the components are chosen lower than in the original design of the existing steam power plant. Since in this particular application i.d.R. no significant additional power is expected, the original generator 10 can often be kept unchanged.

By the advantageous embodiments described above, the disadvantages of the prior art are avoided and the efficiency and the life of the existing steam power plant improved. By keeping as many original parts of the steam power plant as possible, a cost-effective solution for this is provided. In addition, the general infrastructure can be maintained as economically and environmentally sound as possible.

The present invention is not limited by the described embodiments, but is defined only by the scope of the appended claims, as understood by one of ordinary skill in the art. In particular, the subcomponents shown in the exemplary embodiments can be combined with one another in many cases.

LIST OF REFERENCE NUMBERS

1

Steam generator, steam boiler

2

superheater

3

Live steam valve

4

High-pressure turbine

5

Reheater

6

intercept

7

Intermediate pressure turbine

8th

Low-pressure turbine

9

wave

10

Alternator

11

Condenser, condenser

12

shaft bearing

13

condensate pump

14

wave

15

Low-pressure feedwater

16

Low-pressure feedwater

17

Feedwater tank

18

Boiler feed pump

19

High-pressure feedwater preheater

20

High-pressure feedwater preheater

21

High-pressure feedwater preheater

22

Steam power plant with retrofit kit

23

Live steam valve

24

Super-high-pressure turbine

25

Retrofit turbine module

26

intercept

27

Super-intermediate pressure turbine

28

clutch

29

Booster pump

30

Alternator

31

Reheater

32

superheater

33

Reheater

34

modified pressure line

Claims (12)

1. Steam power plant with retrofit kit, the steam power plant having a steam generator (1) with superheater, a steam turbine set including condensation installations (11), connecting pipelines, auxiliary devices and a generator (10), characterized in that at least one retrofit turbine module (25), which is designed for elevated live steam temperatures of > 565°C, preferably 620°C to 720°C, and for unchanged or modified live steam pressure, is provided as the retrofit kit and is connected upstream of the existing steam turbine set, and in that the shaft (14) of the retrofit turbine module (25) and the shaft (9) of the existing steam turbine set are mechanically coupled to one another.
2. Steam power plant according to Claim 1, characterized in that the modified live steam pressure is = 200 bar, preferably 240 bar to 375 bar.
3. Steam power plant according to Claim 1, characterized in that the modified live steam pressure is lower than the live steam pressure of the existing steam turbine set, preferably in the region of 100 bar.
4. Steam power plant according to one of the preceding claims, characterized in that the retrofit turbine module (25) is made from materials which are able to withstand high temperatures, preferably from steel or a nickel-based alloy.
5. Steam power plant according to one of the preceding claims, characterized in that the retrofit turbine module (25) has a single-flow or multiflow super high-pressure turbine (24).
6. Steam power plant according to one of the preceding claims, characterized in that the retrofit turbine module (25) has a single-flow or multiflow super high-pressure turbine (24) and a single-flow or multiflow super intermediate-pressure turbine (27).
7. Steam power plant according to claim 8, characterized in that the super high-pressure turbine (24) and the super intermediate-pressure turbine (27) are arranged in a common housing.
8. Steam power plant according to one of the preceding claims, characterized in that the retrofit kit has a modified steam generator (1) and/or superheater (32) for generating live steam at an elevated steam temperature of > 565°C, preferably 620°C to 720°C, and an unchanged or modified steam pressure.
9. Steam power plant according to one of the preceding claims, characterized in that there is an additional generator (30) or a modified or exchanged generator (10) for taking off the increased power which is generated by the retrofit turbine set (25).
10. Method for retrofitting an existing steam power plant having a steam generator (1) with superheater, a steam turbine set including condensation installations (11), connecting pipelines, auxiliary devices and a generator (10), the method including the following steps:

    connecting a retrofit turbine module (25) for live steam with an elevated steam temperature and an unchanged or modified live steam pressure upstream of the existing turbine set, the shaft (14) of the retrofit turbine module (25) and the shaft (9) of the existing turbine set being mechanically coupled to one another;

    providing a steam generator (1) and/or superheater (32) for providing live steam with an elevated steam temperature.
11. Method for retrofitting a steam power plant according to Claim 10, which also comprises the following step:

    retrofitting or converting the steam generator and the superheater (32) and also the feedwater pump or adding a booster pump (29) and modifying the corresponding pipelines, in order to provide an increased live steam pressure.
12. Method for retrofitting a steam power plant according to Claim 10 or 11, which also includes the following step:

    adding, exchanging or modifying a generator (10) for taking off the increased power which is produced by the retrofit turbine set (25).

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