US20120073520A1 - Continuous evaporator - Google Patents
Continuous evaporator Download PDFInfo
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- US20120073520A1 US20120073520A1 US13/376,469 US201013376469A US2012073520A1 US 20120073520 A1 US20120073520 A1 US 20120073520A1 US 201013376469 A US201013376469 A US 201013376469A US 2012073520 A1 US2012073520 A1 US 2012073520A1
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- Prior art keywords
- steam generator
- evaporator
- waste heat
- tubes
- once
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F1/00—Tubular elements; Assemblies of tubular elements
- F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
- F28F1/40—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only inside the tubular element
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B37/00—Component parts or details of steam boilers
- F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
- F22B37/10—Water tubes; Accessories therefor
- F22B37/101—Tubes having fins or ribs
- F22B37/103—Internally ribbed tubes
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B1/00—Methods of steam generation characterised by form of heating method
- F22B1/02—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers
- F22B1/18—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being a hot gas, e.g. waste gas such as exhaust gas of internal-combustion engines
- F22B1/1807—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being a hot gas, e.g. waste gas such as exhaust gas of internal-combustion engines using the exhaust gases of combustion engines
- F22B1/1815—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being a hot gas, e.g. waste gas such as exhaust gas of internal-combustion engines using the exhaust gases of combustion engines using the exhaust gases of gas-turbines
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B29/00—Steam boilers of forced-flow type
- F22B29/06—Steam boilers of forced-flow type of once-through type, i.e. built-up from tubes receiving water at one end and delivering superheated steam at the other end of the tubes
- F22B29/061—Construction of tube walls
- F22B29/062—Construction of tube walls involving vertically-disposed water tubes
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B39/00—Evaporators; Condensers
- F25B39/02—Evaporators
Definitions
- the invention relates to a once-through evaporator for a horizontal-type waste heat steam generator, having a first evaporator heating surface comprising a plurality of essentially vertically disposed first steam generator tubes through which a flow medium flows from the bottom to the top, and another second evaporator heating surface disposed downstream of the first evaporator heating surface in respect of the flow medium direction and comprising a plurality of other essentially vertically disposed second steam generator tubes through which the medium flows from the bottom to the top.
- the heat contained in the expanded working medium or heating gas from the gas turbine is used to generate steam for the steam turbine.
- Heat transfer takes place in a waste heat steam generator mounted downstream of the gas turbine and in which a plurality of heating surfaces for water preheating, steam generation and steam superheating are normally disposed.
- the heating surfaces are connected into the water/steam circuit of the steam turbine.
- the water/steam circuit nonually contains a plurality of, e.g. three, pressure stages, each pressure stage possibly having an evaporator heating surface.
- a number of alternative design concepts are suitable, namely configuration as a once-through steam generator or as a recirculating steam generator.
- a once-through steam generator the heating of steam generator tubes provided as evaporator tubes results in evaporation of the flow medium in the steam generator tubes in a single pass.
- the circulating water is only partly evaporated as it passes through the evaporator tubes, the water that is not evaporated being is re-fed to the same evaporator tubes for further evaporation after separation of the generated steam.
- a once-through steam generator In contrast to a natural or forced circulation steam generator, a once-through steam generator is not subject to any pressure limitation. A high live steam pressure promotes high thermal efficiency and therefore low CO 2 emissions from a fossil-fired power plant.
- a once-through steam generator has a simple type of construction compared to a recirculating steam generator and can therefore be manufactured particularly inexpensively. Using a steam generator of once-through design as the waste heat steam generator of a gas and steam turbine plant is therefore particularly advantageous for achieving a high overall efficiency of the gas and steam turbine plant without constructional complexity.
- a once-through steam generator designed as a waste heat steam generator can basically be implemented in one of two alternative types of construction, namely vertical or horizontal.
- a horizontal-type once-through steam generator is designed to provide an approximately horizontal flow path for the heating medium or heating gas, e.g. the exhaust gas from the gas turbine, whereas a vertical-type once-through steam generator is designed to provide an approximately vertical flow path for the heating medium.
- a horizontal-type once-through steam generator can be manufactured using particularly simple means and with particularly low production and assembly costs.
- both types particularly in the downstream (in flow medium direction) steam generator tubes of the second evaporator heating surface, an uneven distribution of the two-phase flow medium to the steam generator tubes may occur within each individual row of tubes, resulting in temperature imbalances and mechanical stresses caused by differential thermal expansion.
- expansion bends for example, have therefore hitherto been fitted to compensate for these stresses.
- this measure can be comparatively complex technically in the case of a horizontal-type waste heat steam generator.
- the object of the invention is therefore to specify a once-through evaporator for a waste heat steam generator as described in the introduction, which permits a particularly simple type of construction while providing a particularly long service life.
- This object is achieved according to the invention by providing a plurality of second steam generator tubes with an internal profile.
- the invention is based on the consideration that a particularly simple design of the waste heat steam generator or more specifically of the once-through evaporator could be achieved by dispensing with the hitherto customary expansion bends. In doing so, however, another way must be found of reducing the mechanical stresses caused by temperature imbalances in the parallel connected steam generator tubes of each individual tube row. These occur particularly in the second evaporator heating surface to which the water/steam mixture is applied.
- the temperature imbalances are caused by different proportions of water and steam in the flow medium at the inlet of the individual tubes of a tube row and a resultant differential flow through these tubes. It was realized that this differential flow in the tubes is caused by the frictional pressure drop in the steam generator tubes being low compared to the geodetic pressure drop.
- the laminar boundary layer on the inside of the tubes must be reduced. This can be achieved by producing turbulence in the tube. This effect can be amplified still further by swirling of the flow medium. Swirling of this kind can be produced by advantageously making the internal profile helical-spring-shaped.
- Said frictional pressure drop must be appropriately determined using the normal operating parameters such as tube geometry, the dimensions of the heating gas path and the temperature conditions.
- the geometry of the particular internal profile must then be selected such that the predefined frictional pressure drop of the flow medium is obtained via the respective second steam generator tube. This provides an even better means of preventing temperature imbalances.
- the particular internal profile is provided in the respective second steam generator tube as a kind of internal finning, thereby allowing a particularly simple once-through evaporator or rather waste heat steam generator design.
- the particular internal profile is advantageously inserted in the respective second steam generator tube as a fitted component.
- the internal profile is therefore implemented as a separate component and disposed in the steam generator tubes.
- a plurality of second steam generator tubes are connected in series in the heating gas direction as tube rows. This enables a larger number of parallel connected steam generator tubes to be used for an evaporator heating surface, which means a better heat input due to the enlarged surface.
- the steam generator tubes disposed in series in the heating gas flow direction will be differentially heated in this case.
- the flow medium will be comparatively strongly heated particularly in the steam generator tubes on the heating gas inlet side.
- a through-flow matched to the heating can also be achieved in these steam generator tubes, thereby ensuring a particularly long service life for a waste heat steam generator of simple constructional design.
- the first evaporator heating surface is connected downstream of the second evaporator heating surface in respect of the heating gas direction.
- the advantage of this is that the second evaporator heating surface connected downstream in respect of the flow medium direction and therefore designed for further heating of already evaporated flow medium is also in a comparatively more strongly heated region of the heating gas path.
- a once-through evaporator of this kind can be usefully installed in a waste heat steam generator and the waste heat steam generator employed in a gas and steam turbine plant.
- Said steam generator is advantageously connected downstream of a gas turbine in respect of the heating gas direction.
- supplementary firing equipment can be usefully connected downstream of the gas turbine to increase the heating gas temperature.
- the particular advantages achieved by the invention consist in that, by providing the second evaporator tubes with an internal profile, an improvement is achieved in the distribution of the flow and therefore a reduction in the temperature differences between parallel connected second steam generator tubes and in the resultant mechanical stresses, thereby ensuring a particularly long service life of the waste heat steam generator.
- the appropriate provision of the internal profile enables other complex technical measures such as expansion bends to be dispensed with, while at the same time allowing a particularly simple, cost-saving design of the waste heat steam generator or more particularly of a gas and steam turbine power plant.
- FIG. 1 shows a simplified view in longitudinal section through a horizontal-type steam generator
- FIG. 2 shows a longitudinal section through a steam generator tube with internal finning
- FIG. 3 shows a longitudinal section through a steam generator tube with fitted components
- FIG. 4 shows a plot of tube temperature versus steam content at the heating tube inlet without internal profile
- FIG. 5 shows a plot of tube temperature versus steam content at the heating tube inlet with internal profile
- the once-through evaporator 1 for the waste heat steam generator 2 as shown in FIG. 1 is connected downstream of a gas turbine (not shown in greater detail) in respect of the exhaust gas direction.
- the waste heat steam generator 2 has an enclosing wall 3 which forms a heating gas path 5 for the exhaust gas from the gas turbine which can flow through it in an approximately horizontal heating gas direction indicated by the arrow 4 .
- a plurality of evaporator heating surfaces 8 , 10 of once-through design are disposed in the heating gas path 5 . Although in the exemplary embodiment in FIG. 1 two evaporator heating surfaces 8 , 10 are shown, a larger number of evaporator heating surfaces can also be provided.
- the evaporator heating surfaces 8 , 10 shown in FIG. 1 each comprise, in the manner of a tube bundle, a plurality of tube rows 11 and 12 respectively, disposed in series in the heating gas direction.
- Each row of tubes 11 , 12 in turn comprises a plurality of steam generator tubes 13 and 14 respectively, disposed in parallel with one another in the heating gas direction, only one of which is visible for each tube row 11 , 12 .
- Said approximately vertically disposed first steam generator tubes 13 of the first evaporator heating surface 8 which are connected in parallel for the passage of a flow medium W are connected on the output side to a common outlet header 15 .
- the likewise approximately vertically disposed second steam generator tubes 14 of the second evaporator heating surface 10 which are connected in parallel for the passage of a flow medium W are likewise connected on the output side to a common outlet header 16 .
- a comparatively more complex header system can also be provided for the two evaporator heating surfaces 8 , 10 .
- a downcomer system 17 connects the steam generator tubes 13 of the first evaporator heating surface 8 to the downstream (in terms of flow medium) steam generator tubes 14 of the second evaporator heating surface 10 .
- the flow medium W which can be applied to the evaporator system constituted by the evaporator heating surfaces 8 , 10 is evaporated in one passage through the evaporator system and, after exiting the second evaporator heating surface 10 , is discharged as steam D.
- the evaporator system formed by the evaporator heating surfaces 8 , 10 is connected into the water/steam circuit (not shown in greater detail) of a steam turbine.
- a number of other heating surfaces 20 schematically indicated in FIG. 1 can be connected into the water/steam circuit of the steam turbine.
- Said heating surfaces 20 can be, for example, superheaters, medium pressure evaporators, low pressure evaporators and/or preheaters.
- the second steam generator tubes 14 now have a helical-spring-shaped internal profile 22 which is illustrated in FIGS. 2 and 3 .
- the profile geometry thereof is selected such that the swirl- and turbulence-induced frictional pressure drop of the flow medium W in the steam generator tubes 14 is accordingly high enough to ensure an even through-flow within a tube row 11 , thereby reducing temperature imbalances.
- Said internal profile 22 can be directly incorporated in the steam generator tubes 14 as a kind of internal finning 23 .
- fitted components 24 can be used as the internal profile 22 , which in particular allows retrofitting to existing once-through evaporators 1 .
- FIGS. 4 and 5 show the effect of the internal profile 22 on the temperature differences.
- FIG. 4 shows the situation without internal profile 22 .
- the average tube wall temperature 25 varies between approximately 460° C. and 360° C.
- the tube outlet wall temperature 27 between 480° C. and 370° C., as a function of the steam content 29 .
- FIG. 5 which explains the situation with internal profile 22 it is shown that these variations are reduced to approximately 440° C. to 390° C. and 470° C. to 405° C. respectively.
- the temperature differences between tubes with different steam content at the inlet are therefore significantly reduced.
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Abstract
A continuous evaporator for a horizontal waste heat steam generator is provided. The continuous evaporator includes a first evaporator heating surface that has a number of essentially vertically arranged first steam generating tubes wherein the circulation takes place from the bottom to the top, and another second evaporator heating surface located downstream of the first evaporator heating surface on the side of the flow medium, the second evaporator heating surface including a number of other essentially vertically arranged second steam generating tubes wherein the circulation takes place from the bottom to the top is provided. In order to provide a continuous evaporator with an especially simple structure and an especially long service life, a number of second steam generator tubes have an inner profiled element.
Description
- This application is the U.S. National Stage of International Application No. PCT/EP2010/055886, filed Apr. 30, 2010 and claims the benefit thereof. The International Application claims the benefits of Getman application No. 10 20009 024 587.1 DE filed Jun. 10, 2009. All of the applications are incorporated by reference herein in their entirety.
- The invention relates to a once-through evaporator for a horizontal-type waste heat steam generator, having a first evaporator heating surface comprising a plurality of essentially vertically disposed first steam generator tubes through which a flow medium flows from the bottom to the top, and another second evaporator heating surface disposed downstream of the first evaporator heating surface in respect of the flow medium direction and comprising a plurality of other essentially vertically disposed second steam generator tubes through which the medium flows from the bottom to the top.
- In a gas and steam turbine plant, the heat contained in the expanded working medium or heating gas from the gas turbine is used to generate steam for the steam turbine. Heat transfer takes place in a waste heat steam generator mounted downstream of the gas turbine and in which a plurality of heating surfaces for water preheating, steam generation and steam superheating are normally disposed. The heating surfaces are connected into the water/steam circuit of the steam turbine. The water/steam circuit nonually contains a plurality of, e.g. three, pressure stages, each pressure stage possibly having an evaporator heating surface.
- For the steam generator mounted downstream of the gas turbine in the heating gas path as a waste-heat steam generator, a number of alternative design concepts are suitable, namely configuration as a once-through steam generator or as a recirculating steam generator. In the case of a once-through steam generator, the heating of steam generator tubes provided as evaporator tubes results in evaporation of the flow medium in the steam generator tubes in a single pass. In contrast, in the case of a natural or forced circulation steam generator, the circulating water is only partly evaporated as it passes through the evaporator tubes, the water that is not evaporated being is re-fed to the same evaporator tubes for further evaporation after separation of the generated steam.
- In contrast to a natural or forced circulation steam generator, a once-through steam generator is not subject to any pressure limitation. A high live steam pressure promotes high thermal efficiency and therefore low CO2 emissions from a fossil-fired power plant. In addition, a once-through steam generator has a simple type of construction compared to a recirculating steam generator and can therefore be manufactured particularly inexpensively. Using a steam generator of once-through design as the waste heat steam generator of a gas and steam turbine plant is therefore particularly advantageous for achieving a high overall efficiency of the gas and steam turbine plant without constructional complexity.
- A once-through steam generator designed as a waste heat steam generator can basically be implemented in one of two alternative types of construction, namely vertical or horizontal. A horizontal-type once-through steam generator is designed to provide an approximately horizontal flow path for the heating medium or heating gas, e.g. the exhaust gas from the gas turbine, whereas a vertical-type once-through steam generator is designed to provide an approximately vertical flow path for the heating medium.
- In contrast to a once-through steam generator of vertical design, a horizontal-type once-through steam generator can be manufactured using particularly simple means and with particularly low production and assembly costs. In both types, particularly in the downstream (in flow medium direction) steam generator tubes of the second evaporator heating surface, an uneven distribution of the two-phase flow medium to the steam generator tubes may occur within each individual row of tubes, resulting in temperature imbalances and mechanical stresses caused by differential thermal expansion. In order to prevent damage to the waste heat steam generator, expansion bends, for example, have therefore hitherto been fitted to compensate for these stresses. However, this measure can be comparatively complex technically in the case of a horizontal-type waste heat steam generator.
- The object of the invention is therefore to specify a once-through evaporator for a waste heat steam generator as described in the introduction, which permits a particularly simple type of construction while providing a particularly long service life.
- This object is achieved according to the invention by providing a plurality of second steam generator tubes with an internal profile.
- The invention is based on the consideration that a particularly simple design of the waste heat steam generator or more specifically of the once-through evaporator could be achieved by dispensing with the hitherto customary expansion bends. In doing so, however, another way must be found of reducing the mechanical stresses caused by temperature imbalances in the parallel connected steam generator tubes of each individual tube row. These occur particularly in the second evaporator heating surface to which the water/steam mixture is applied. The temperature imbalances are caused by different proportions of water and steam in the flow medium at the inlet of the individual tubes of a tube row and a resultant differential flow through these tubes. It was realized that this differential flow in the tubes is caused by the frictional pressure drop in the steam generator tubes being low compared to the geodetic pressure drop. In fact, a flow with a high proportion of steam in the flow medium flows comparatively quickly through individual steam generator tubes with low frictional pressure drop, whereas a flow with a high proportion of water is disadvantaged because of its higher geodetic pressure drop due to weight and may tend to stagnation. In order to make the flows uniform, the frictional pressure drop must therefore be increased. This can be achieved by a plurality of second steam generator tubes having an internal profile which causes an additional frictional pressure drop of this kind.
- In order to a achieve a particularly high additional frictional pressure drop, the laminar boundary layer on the inside of the tubes must be reduced. This can be achieved by producing turbulence in the tube. This effect can be amplified still further by swirling of the flow medium. Swirling of this kind can be produced by advantageously making the internal profile helical-spring-shaped.
- Said frictional pressure drop must be appropriately determined using the normal operating parameters such as tube geometry, the dimensions of the heating gas path and the temperature conditions. Advantageously, the geometry of the particular internal profile must then be selected such that the predefined frictional pressure drop of the flow medium is obtained via the respective second steam generator tube. This provides an even better means of preventing temperature imbalances.
- In an advantageous embodiment, the particular internal profile is provided in the respective second steam generator tube as a kind of internal finning, thereby allowing a particularly simple once-through evaporator or rather waste heat steam generator design.
- In order to facilitate retrofitting to existing steam generators and/or achieve greater flexibility in the design of steam generators in respect of the tube geometries, the particular internal profile is advantageously inserted in the respective second steam generator tube as a fitted component. The internal profile is therefore implemented as a separate component and disposed in the steam generator tubes.
- In an advantageous embodiment, a plurality of second steam generator tubes are connected in series in the heating gas direction as tube rows. This enables a larger number of parallel connected steam generator tubes to be used for an evaporator heating surface, which means a better heat input due to the enlarged surface. However, the steam generator tubes disposed in series in the heating gas flow direction will be differentially heated in this case. The flow medium will be comparatively strongly heated particularly in the steam generator tubes on the heating gas inlet side. However, as a result of the described design of the second steam generator tubes with an internal profile, a through-flow matched to the heating can also be achieved in these steam generator tubes, thereby ensuring a particularly long service life for a waste heat steam generator of simple constructional design.
- In an advantageous embodiment, the first evaporator heating surface is connected downstream of the second evaporator heating surface in respect of the heating gas direction. The advantage of this is that the second evaporator heating surface connected downstream in respect of the flow medium direction and therefore designed for further heating of already evaporated flow medium is also in a comparatively more strongly heated region of the heating gas path.
- A once-through evaporator of this kind can be usefully installed in a waste heat steam generator and the waste heat steam generator employed in a gas and steam turbine plant. Said steam generator is advantageously connected downstream of a gas turbine in respect of the heating gas direction. In this configuration, supplementary firing equipment can be usefully connected downstream of the gas turbine to increase the heating gas temperature.
- The particular advantages achieved by the invention consist in that, by providing the second evaporator tubes with an internal profile, an improvement is achieved in the distribution of the flow and therefore a reduction in the temperature differences between parallel connected second steam generator tubes and in the resultant mechanical stresses, thereby ensuring a particularly long service life of the waste heat steam generator. The appropriate provision of the internal profile enables other complex technical measures such as expansion bends to be dispensed with, while at the same time allowing a particularly simple, cost-saving design of the waste heat steam generator or more particularly of a gas and steam turbine power plant.
- An exemplary embodiment of the invention will now be explained in greater detail with reference to the accompanying drawings in which:
-
FIG. 1 shows a simplified view in longitudinal section through a horizontal-type steam generator, -
FIG. 2 shows a longitudinal section through a steam generator tube with internal finning, -
FIG. 3 shows a longitudinal section through a steam generator tube with fitted components, -
FIG. 4 shows a plot of tube temperature versus steam content at the heating tube inlet without internal profile and -
FIG. 5 shows a plot of tube temperature versus steam content at the heating tube inlet with internal profile - Identical parts are denoted by the same reference characters in all the figures.
- The once-through
evaporator 1 for the waste heat steam generator 2 as shown inFIG. 1 is connected downstream of a gas turbine (not shown in greater detail) in respect of the exhaust gas direction. The waste heat steam generator 2 has an enclosingwall 3 which forms aheating gas path 5 for the exhaust gas from the gas turbine which can flow through it in an approximately horizontal heating gas direction indicated by thearrow 4. A plurality ofevaporator heating surfaces 8, 10 of once-through design are disposed in theheating gas path 5. Although in the exemplary embodiment inFIG. 1 twoevaporator heating surfaces 8, 10 are shown, a larger number of evaporator heating surfaces can also be provided. - The
evaporator heating surfaces 8, 10 shown inFIG. 1 each comprise, in the manner of a tube bundle, a plurality oftube rows tubes steam generator tubes tube row steam generator tubes 13 of the first evaporator heating surface 8 which are connected in parallel for the passage of a flow medium W are connected on the output side to acommon outlet header 15. The likewise approximately vertically disposed secondsteam generator tubes 14 of the secondevaporator heating surface 10 which are connected in parallel for the passage of a flow medium W are likewise connected on the output side to acommon outlet header 16. A comparatively more complex header system can also be provided for the twoevaporator heating surfaces 8, 10. Adowncomer system 17 connects thesteam generator tubes 13 of the first evaporator heating surface 8 to the downstream (in terms of flow medium)steam generator tubes 14 of the secondevaporator heating surface 10. - The flow medium W which can be applied to the evaporator system constituted by the
evaporator heating surfaces 8, 10 is evaporated in one passage through the evaporator system and, after exiting the secondevaporator heating surface 10, is discharged as steam D. The evaporator system formed by theevaporator heating surfaces 8, 10 is connected into the water/steam circuit (not shown in greater detail) of a steam turbine. In addition to the evaporator system comprising theevaporator heating surfaces 8, 10, a number of other heating surfaces 20 schematically indicated inFIG. 1 can be connected into the water/steam circuit of the steam turbine. Said heating surfaces 20 can be, for example, superheaters, medium pressure evaporators, low pressure evaporators and/or preheaters. - The second
steam generator tubes 14 now have a helical-spring-shapedinternal profile 22 which is illustrated inFIGS. 2 and 3 . The profile geometry thereof is selected such that the swirl- and turbulence-induced frictional pressure drop of the flow medium W in thesteam generator tubes 14 is accordingly high enough to ensure an even through-flow within atube row 11, thereby reducing temperature imbalances. Saidinternal profile 22 can be directly incorporated in thesteam generator tubes 14 as a kind ofinternal finning 23. Alternatively, fittedcomponents 24 can be used as theinternal profile 22, which in particular allows retrofitting to existing once-throughevaporators 1. - The effect of the
internal profile 22 on the temperature differences is illustrated in the graphs inFIGS. 4 and 5 which plot the averagetube wall temperature 25 and the tubeoutlet wall temperature 27 against thesteam component 29 of the flow medium at the tube inlet.FIG. 4 shows the situation withoutinternal profile 22. Here the averagetube wall temperature 25 varies between approximately 460° C. and 360° C., the tubeoutlet wall temperature 27 between 480° C. and 370° C., as a function of thesteam content 29. InFIG. 5 which explains the situation withinternal profile 22 it is shown that these variations are reduced to approximately 440° C. to 390° C. and 470° C. to 405° C. respectively. The temperature differences between tubes with different steam content at the inlet are therefore significantly reduced. - By reducing the temperature differences of tubes with differing steam content at the flow inlet, the mechanical stress loading of the waste heat steam generator 2 is reduced and a particularly long service life is ensured, while at the same time allowing a simple type of construction by eliminating the hitherto customary expansion bends.
Claims (16)
1-9. (canceled)
10. A once-through evaporator for a horizontal-type waste heat steam generator, comprising:
a first evaporator heating surface comprising a first plurality of essentially vertically disposed first steam generator tubes through which a flow medium flows from bottom to top; and
a second evaporator heating surface connected downstream of the first evaporator heating surface with respect to the flow medium direction and comprising a second plurality of essentially vertically disposed second steam generator tubes through which the flow medium flows from bottom to top,
wherein the second plurality of second steam generator tubes each include an internal profile.
11. The once-through evaporator as claimed in claim 10 , wherein the internal profile is helical-spring-shaped.
12. The once-through evaporator as claimed in claim 10 , wherein the profile geometry of the respective internal profile is selected such that a specified frictional pressure drop of the flow medium is obtained via a respective second steam generator tube.
13. The once-through evaporator as claimed in claim 10 , wherein the respective internal profile is provided as a kind of internal finning in a respective second steam generator tube.
14. The once-through evaporator as claimed in claim 10 , wherein the respective internal profile is installed as a fitted component in a respective second steam generator tube.
15. The once-through evaporator as claimed in claim 10 , wherein the plurality of second steam generator tubes is connected in series as tube rows in a heating gas direction.
16. The once-through evaporator as claimed in claim 10 , wherein the first evaporator heating surface is connected downstream of the second evaporator heating surface with respect to the heating gas direction.
17. A waste heat steam generator, comprising:
a once-through evaporator as claimed in claim 10 .
18. The waste heat steam generator as claimed in claim 17 , wherein a gas turbine is disposed upstream of the waste heat steam generator with respect to a heating gas direction.
19. The waste heat steam generator as claimed in claim 17 , wherein the internal profile is helical-spring-shaped.
20. The waste heat steam generator as claimed in claim 17 , wherein the profile geometry of the respective internal profile is selected such that a specified frictional pressure drop of the flow medium is obtained via a respective second steam generator tube.
21. The waste heat steam generator as claimed in claim 17 , wherein the respective internal profile is provided as a kind of internal finning in a respective second steam generator tube.
22. The waste heat steam generator as claimed in claim 17 , wherein the respective internal profile is installed as a fitted component in a respective second steam generator tube.
23. The waste heat steam generator as claimed in claim 17 , wherein the plurality of second steam generator tubes is connected in series as tube rows in a heating gas direction.
24. The waste heat steam generator as claimed in claim 17 , wherein the first evaporator heating surface is connected downstream of the second evaporator heating surface with respect to the heating gas direction.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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DE102009024587.1 | 2009-06-10 | ||
DE102009024587A DE102009024587A1 (en) | 2009-06-10 | 2009-06-10 | Flow evaporator |
PCT/EP2010/055886 WO2010142495A2 (en) | 2009-06-10 | 2010-04-30 | Continuous evaporator |
Publications (1)
Publication Number | Publication Date |
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US20120073520A1 true US20120073520A1 (en) | 2012-03-29 |
Family
ID=43069748
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/376,469 Abandoned US20120073520A1 (en) | 2009-06-10 | 2010-04-30 | Continuous evaporator |
Country Status (12)
Country | Link |
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US (1) | US20120073520A1 (en) |
EP (1) | EP2440847A2 (en) |
JP (1) | JP2012529613A (en) |
KR (1) | KR20120027021A (en) |
CN (1) | CN102667337A (en) |
AU (1) | AU2010257702A1 (en) |
BR (1) | BRPI1013116A2 (en) |
CA (1) | CA2764939A1 (en) |
DE (1) | DE102009024587A1 (en) |
RU (1) | RU2011153331A (en) |
TW (1) | TW201043874A (en) |
WO (1) | WO2010142495A2 (en) |
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US20110197830A1 (en) * | 2008-09-09 | 2011-08-18 | Brueckner Jan | Continuous steam generator |
US20150369085A1 (en) * | 2014-06-20 | 2015-12-24 | Panasonic Intellctual Property Management Co., Ltd | Evaporator, rankine cycle apparatus, and combined heat and power system |
CN108263904A (en) * | 2018-01-15 | 2018-07-10 | 芜湖航天特种电缆厂股份有限公司 | Preheat cable conveyer |
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EP2390567A1 (en) * | 2010-05-31 | 2011-11-30 | Siemens Aktiengesellschaft | Device for producing fixture units for steam generator pipes |
DE102013206014A1 (en) * | 2013-04-05 | 2014-10-09 | Dürr Systems GmbH | Energy converter system and assemblies for this |
CN110094709B (en) * | 2019-05-28 | 2024-04-26 | 上海锅炉厂有限公司 | Direct-current evaporator and design method thereof |
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- 2009-06-10 DE DE102009024587A patent/DE102009024587A1/en not_active Withdrawn
-
2010
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- 2010-04-30 KR KR1020117029457A patent/KR20120027021A/en not_active Application Discontinuation
- 2010-04-30 BR BRPI1013116A patent/BRPI1013116A2/en not_active Application Discontinuation
- 2010-04-30 JP JP2012514403A patent/JP2012529613A/en active Pending
- 2010-04-30 CN CN201080025823XA patent/CN102667337A/en active Pending
- 2010-04-30 CA CA2764939A patent/CA2764939A1/en not_active Abandoned
- 2010-04-30 WO PCT/EP2010/055886 patent/WO2010142495A2/en active Application Filing
- 2010-04-30 AU AU2010257702A patent/AU2010257702A1/en not_active Abandoned
- 2010-04-30 RU RU2011153331/06A patent/RU2011153331A/en unknown
- 2010-04-30 US US13/376,469 patent/US20120073520A1/en not_active Abandoned
- 2010-04-30 EP EP10718147A patent/EP2440847A2/en not_active Withdrawn
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CN108263904A (en) * | 2018-01-15 | 2018-07-10 | 芜湖航天特种电缆厂股份有限公司 | Preheat cable conveyer |
Also Published As
Publication number | Publication date |
---|---|
KR20120027021A (en) | 2012-03-20 |
CA2764939A1 (en) | 2010-12-16 |
JP2012529613A (en) | 2012-11-22 |
RU2011153331A (en) | 2013-07-20 |
WO2010142495A3 (en) | 2012-06-07 |
AU2010257702A1 (en) | 2012-01-12 |
TW201043874A (en) | 2010-12-16 |
DE102009024587A1 (en) | 2010-12-16 |
BRPI1013116A2 (en) | 2016-04-05 |
EP2440847A2 (en) | 2012-04-18 |
WO2010142495A2 (en) | 2010-12-16 |
CN102667337A (en) | 2012-09-12 |
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