WO1997014930A2 - Method and device for producing solar steam - Google Patents

Method and device for producing solar steam Download PDF

Info

Publication number
WO1997014930A2
WO1997014930A2 PCT/DE1996/001887 DE9601887W WO9714930A2 WO 1997014930 A2 WO1997014930 A2 WO 1997014930A2 DE 9601887 W DE9601887 W DE 9601887W WO 9714930 A2 WO9714930 A2 WO 9714930A2
Authority
WO
WIPO (PCT)
Prior art keywords
receiver
tube
water
receiver tube
steam
Prior art date
Application number
PCT/DE1996/001887
Other languages
German (de)
French (fr)
Other versions
WO1997014930A3 (en
Inventor
Hans-Christian TRÄNKENSCHUH
Reinhard Rippel
Hans-Jürgen CIRKEL
Wolfgang Köhler
Wolfgang Kastner
Original Assignee
Siemens Aktiengesellschaft
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens Aktiengesellschaft filed Critical Siemens Aktiengesellschaft
Publication of WO1997014930A2 publication Critical patent/WO1997014930A2/en
Publication of WO1997014930A3 publication Critical patent/WO1997014930A3/en

Links

Classifications

    • 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
    • F22B1/006—Methods of steam generation characterised by form of heating method using solar heat
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S10/00—Solar heat collectors using working fluids
    • F24S10/70—Solar heat collectors using working fluids the working fluids being conveyed through tubular absorbing conduits
    • F24S10/75—Solar heat collectors using working fluids the working fluids being conveyed through tubular absorbing conduits with enlarged surfaces, e.g. with protrusions or corrugations
    • F24S10/753—Solar heat collectors using working fluids the working fluids being conveyed through tubular absorbing conduits with enlarged surfaces, e.g. with protrusions or corrugations the conduits being parallel to each other
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S20/00—Solar heat collectors specially adapted for particular uses or environments
    • F24S20/20—Solar heat collectors for receiving concentrated solar energy, e.g. receivers for solar power plants
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S10/00—Solar heat collectors using working fluids
    • F24S10/70—Solar heat collectors using working fluids the working fluids being conveyed through tubular absorbing conduits
    • F24S10/75—Solar heat collectors using working fluids the working fluids being conveyed through tubular absorbing conduits with enlarged surfaces, e.g. with protrusions or corrugations
    • F24S2010/751—Special fins
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/40—Solar thermal energy, e.g. solar towers
    • Y02E10/44—Heat exchange systems

Definitions

  • the invention relates to a method and a device for generating solar steam.
  • solar power plants the solar radiation incident on the ground serves as a heat source for generating solar steam for a subsequent energy conversion.
  • Examples of solar thermal power plants are tower and dish power plants.
  • the solar radiation is concentrated on a receiver in the tower with mirrors, the heliostats, placed on racks on the ground, and is used there to heat a heat transfer medium, for example water.
  • the mirrors have to be automatically adjusted in the daily course of the sun by mechanical adjustment and therefore require a control device with a corresponding supply line.
  • the parabolic mirror and receiver form a fixed unit.
  • the receiver is fixed in the focal point of the parabolic mirror.
  • the parabolic mirror focuses the sunlight on the receiver.
  • the receiver comprises at least one receiver tube.
  • the heat transfer medium is vaporized directly in the receiver tube to form solar steam. This process is referred to as direct evaporation.
  • a heat exchanger is known from German Offenlegungsschrift 25 36 800, which consists of a thin-walled inner tube and a thin-walled outer tube which is arranged coaxially with respect to the inner tube. Both tubes are made of a material with good thermal conductivity.
  • the outer tube has a series of helical shafts along a substantial area of the inner one
  • the waves form a series of helical wave crests and wave troughs on the inner and outer surface of the tube.
  • the wave troughs on the inner surface touch helical sealing points on the outer surface of the inner tube and thus form at least one helically extending channel around the inner tube for the medium for heat exchange.
  • Several helical channels are obtained if the corrugations consist of several helical lines.
  • the medium in the operating state is only in the liquid state. It only flows in one direction, i.e. in the direction of the pipe or in the direction of the channel formed.
  • the outer channel is bidided by a web extending helically around an inner tube or by an outer tube which is wound helically around an inner tube.
  • the invention is based on the object of specifying a method for generating solar steam, in particular in a tower or dish power plant, in which at the same time the overall efficiency of the solar power plant is increased and the operating costs are reduced.
  • a device for performing the method is to be specified.
  • the first-mentioned object is achieved according to the invention by a method for generating solar steam with at least one receiver tube, wherein the receiver tube is flowed through by water at least over part of its length and part of the water flows through perpendicularly to it
  • a device for generating solar steam which comprises at least one receiver with at least one receiver tube, water flowing through the receiver tube, in which means are provided with which part of the water in the Flow through the receiver tube receives a velocity component oriented perpendicular to the flow direction.
  • the velocity component perpendicular to the flow direction enables a water film to form and / or be retained on the inside of the receiver tube at all times when the solar power plant is in operation.
  • a boiling crisis and the consequent deterioration in the heat transfer between the material of the tube jacket and the heat transfer medium flowing through the receiver tube, the water, can thus be avoided.
  • This improves the overall efficiency of the solar power plant and at the same time increases the service life of the receiver tube. Due to the longer service life of the receiver tube, the costs for operating the solar power plant, for example a tower or dish power plant, are reduced.
  • the entire length of the receiver tube is preferably flowed through by water. During the operation of the solar power plant, there is partially water or wet steam in the entire receiver tube and therefore no solar superheated steam.
  • wet steam consists partly of steam and partly water.
  • the prerequisite that a portion of water or wet steam is present in the entire receiver tube is a necessary prerequisite for the generation or maintenance of a water film on the inside of the receiver tube.
  • the water for feeding into the receiver tube is extracted from the steam cycle of a fossil-fueled one
  • Receiver tubes each arranged at least one rib.
  • an additional swirl is imparted to the heat-absorbing water, as a result of which the water film on the inside of the receiver tubes also with very high steam contents of the wet steam, i.e. in other words the solar steam, is still preserved.
  • the advantages of internally finned tubes when used in Benson steam generator technology are the publication "Evaporator concepts for Benson steam generators, current status and new developments" by J.Franke et al. , VGB Kraftwerkstechnik 73, 1993, Issue 4, pages 352 - 361.
  • the rib is preferably arranged helically.
  • the helical arrangement of the rib enables simple technical implementation.
  • a pitch angle oc between a plane perpendicular to the tube axis and the flanks of the rib is less than 60 °, preferably less than 55. Heat transfer measurements have shown that the improvement in heat transfer is particularly pronounced at these gradient angles ⁇ .
  • the receiver tubes are arranged parallel to one another.
  • the receiver tubes are preferably welded to one another and arranged in one plane. This enables the receiver tubes to be packed tightly, which in turn results in an increase in the overall efficiency of the solar power plant.
  • the receiver tubes are separated from one another by webs.
  • the use of webs which separate the receiver tubes from one another increases the absorption area for the incident solar radiation.
  • FIG. 1 to 3 show devices for generating solar steam in schematic representations.
  • a device for generating solar steam comprises a receiver 2 with a receiver tube 4.
  • the device is part of a solar power plant, for example a tower or dish power plant.
  • the heat transfer medium for example water, flows through the receiver tube 4 in the flow direction 6 at least over part of its length.
  • Six ribs 12 are arranged helically on the inside 10 of the receiver tube 4. Two adjacent ribs 12 delimit a channel 18.
  • the water that flows through the receiver tube 4 is evaporated according to the principle of direct evaporation and thus solar steam is generated in the receiver tube 4.
  • the receiver tube 4 for example from the water vapor cycle of a fossil-fired power plant, that a portion of water is always present in the receiver tube 4 at all times during operation, despite the evaporation. This produces wet steam, ie steam and water are present in the receiver tube 4 at the same time.
  • the proportion of the water flowing in the channels 18 receives an additional swirl through the ribs 12, i.e. some of the water receives a speed component perpendicular to the direction of flow 6. In the receiver tube 4 there are thus portions of water which each flow in different directions. This effect is also achieved when only one rib 12 is used.
  • the flanks 30 of the ribs 12 enclose a pitch angle oc with a plane 32 perpendicular to the tube axis 30.
  • This pitch angle ⁇ is less than 60. In an embodiment that is not further illustrated, it is smaller than 55, for example 50. This enables a water film to form or remain on the inside 10 of the receiver tube 4 at all times during operation. Accordingly, a boiling crisis on the inside 10 of the receiver tube 4 is avoided and the heat transfer between the tube jacket 20 of the receiver tube 4 and the water flowing in the receiver tube 4 is improved.
  • receiver tubes 4 of the receiver 2 are welded together and arranged in one plane.
  • the pipe jackets 20 of the receiver pipes 4 are welded directly to one another by welds 24, which are arranged parallel to the longitudinal beads 28.
  • the longitudinal beads 28 are part of the receiver tubes 4 and facilitate the assembly welding the receiver tubes 4.
  • the welded receiver tubes 4 form a tube wall 14.
  • the receiver tubes 4 are packed tightly, ie that for a given tube diameter the receiver tubes 4 in this tube wall 14 contain the greatest possible amount of heat ⁇ medium medium water flows through the receiver 2.
  • webs 16 are arranged in the tube wall 14 between the receiver tubes 4. These webs 16, for example made of the same material as the receiver tubes 4, are connected to the receiver tubes 4 by welds 24. The webs 16 enlarge the absorption area for the incident solar radiation. The heat of the solar radiation absorbed by the webs is passed on to the receiver tubes 4 via the weld seams 24.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Energy (AREA)
  • Sustainable Development (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Dispersion Chemistry (AREA)
  • Geometry (AREA)
  • Heat Treatment Of Water, Waste Water Or Sewage (AREA)
  • Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
  • Engine Equipment That Uses Special Cycles (AREA)

Abstract

In the present method of producing solar steam with at least one receiver pipe (4), water flows through the receiver pipe (4) along at least part of its length, a proportion of the water acquiring a speed component perpendicular to the through-flow direction (6). This measure prevents a boiling crisis in the receiver tube (4).

Description

Beschreibungdescription
Verfahren und Vorrichtung zum Erzeugen von solarem DampfMethod and device for generating solar steam
Die Erfindung bezieht sich auf ein Verfahren und eine Vor¬ richtung zum Erzeugen von solarem Dampf.The invention relates to a method and a device for generating solar steam.
Bei Solarkraftwerken dient die am Erdboden einfallende Son¬ nenstrahlung als Wärmequelle zum Erzeugen von solarem Dampf für eine nachgeschaltete Energieumwandlung. Beispiele für solarthermische Kraftwerke sind Turm- und Dish-Kraftwerke.In solar power plants, the solar radiation incident on the ground serves as a heat source for generating solar steam for a subsequent energy conversion. Examples of solar thermal power plants are tower and dish power plants.
Beim Turmkraftwerk wird die Solarstrahlung mit am Erdboden auf Gestellen aufgestellten Spiegeln, den Heliostaten, auf einen Receiver im Turm konzentriert und dort zum Erwärmen ei¬ nes Wärmeträgermediums, beispielsweise Wasser, verwendet. Die Spiegel müssen im täglichen Sonnenlauf durch mechanische Ver¬ stellung automatisch nachgeführt werden und benötigen daher eine Steuereinrichtung mit einer entsprechenden Versorgungs- leitung.In the tower power plant, the solar radiation is concentrated on a receiver in the tower with mirrors, the heliostats, placed on racks on the ground, and is used there to heat a heat transfer medium, for example water. The mirrors have to be automatically adjusted in the daily course of the sun by mechanical adjustment and therefore require a control device with a corresponding supply line.
Beim Dish-Kraftwerk bilden Parabolspiegel und Receiver eine feste Einheit. Der Receiver ist dabei im Brennpunkt des Para¬ bolspiegels fixiert. Das Sonnenlicht wird von dem Parabol- spiegel auf den Receiver fokussiert.In the Dish power plant, the parabolic mirror and receiver form a fixed unit. The receiver is fixed in the focal point of the parabolic mirror. The parabolic mirror focuses the sunlight on the receiver.
Bei beiden Typen von solarthermischen Kraftwerken umfaßt der Receiver mindestens ein Receiverrohr. Das Wärmeträgermedium wird hierbei direkt in dem Receiverrohr zu solarem Dampf ver- dampft. Dieses Verfahren wird als Direktverdampfung bezeich¬ net.In both types of solar thermal power plants, the receiver comprises at least one receiver tube. The heat transfer medium is vaporized directly in the receiver tube to form solar steam. This process is referred to as direct evaporation.
Aus dem Bericht "Thermal Fatigue Failure at the White Cliffε Solar Thermal Power Plant" von P. Bannister, Journal of Solar Energy Engineering, Vol. 117, (1995), Seiten 57 - 58, ist be¬ kannt, daß bei der Direktverdampfung in dem Receiverrohr zwangsläufig eine Siedekrise auftritt. Als ungenügend erweist sich hierbei die starke Temperaturerhöhung im Wandmaterial des Rohrmantels des Receiverrohres, wodurch wiederum Schäden in demselbigen entstehen. Dieser Effekt führt zudem zu einem relativ geringen Gesamtwirkungsgrad des solarthermischen Kraftwerkes und es entstehen zugleich Mehrkosten durch einen erhöhten Materialaufwand aufgrund der verringerten Lebens¬ dauer des Receiverrohres.From the report "Thermal Fatigue Failure at the White Cliffε Solar Thermal Power Plant" by P. Bannister, Journal of Solar Energy Engineering, Vol. 117, (1995), pages 57-58, it is known that in direct evaporation in a boiling crisis inevitably occurs in the receiver tube. Proven insufficient the strong temperature increase in the wall material of the tube jacket of the receiver tube, which in turn causes damage to the same. This effect also leads to a relatively low overall efficiency of the solar thermal power plant and, at the same time, additional costs arise due to an increased material expenditure due to the reduced service life of the receiver tube.
Desweiteren ist aus der Deutschen Offenlegungsschrift 25 36 800 ein Wärmetauscher bekannt, der aus einem dünnwandigen in¬ neren Rohr und einem dünnwandigen äußeren Rohr, welches koa¬ xial in Bezug zu dem inneren Rohr angeordnet ist, besteht. Beide Rohre sind aus einem Werkstoff mit guten Wärmeleitei¬ genschaften. Das äußere Rohr hat eine Serie von schraubenför- migen Wellen längs einem wesentlichen Bereich des innerenFurthermore, a heat exchanger is known from German Offenlegungsschrift 25 36 800, which consists of a thin-walled inner tube and a thin-walled outer tube which is arranged coaxially with respect to the inner tube. Both tubes are made of a material with good thermal conductivity. The outer tube has a series of helical shafts along a substantial area of the inner one
Rohres. Die Wellen bilden eine Reihe von schraubenförmig ver¬ laufenden Wellenbergen und Wellentälern an der inneren und äußeren Oberfläche des Rohres. Die Wellentäler an der inneren Oberfläche berühren schraubenförmige Dichtungsstellen an der äußeren Oberfläche des inneren Rohres und bilden somit wenig¬ stens einen schraubenförmig verlaufenden Kanal um das innere Rohr für das Medium zum Wärmetauschen. Man erhält mehrere schraubenförmige Kanäle falls die Wellungen aus mehreren Schraubenlinien bestehen. In beiden Rohren, sowohl im inneren als auch im äußeren Rohr, ist das Medium im Betriebszustand ausschließlich im flüssigen Zustand. Es strömt dabei jeweils nur in eine Richtung, d.h. in Richtung des Rohres bzw. in Richtung des ausgebildeten Kanales.Tube. The waves form a series of helical wave crests and wave troughs on the inner and outer surface of the tube. The wave troughs on the inner surface touch helical sealing points on the outer surface of the inner tube and thus form at least one helically extending channel around the inner tube for the medium for heat exchange. Several helical channels are obtained if the corrugations consist of several helical lines. In both tubes, both in the inner and in the outer tube, the medium in the operating state is only in the liquid state. It only flows in one direction, i.e. in the direction of the pipe or in the direction of the channel formed.
Ähnliche Vorrichtungen sind auch aus den US-Patentschriften 3 952 230 und 4 324 230 bekannt. Dabei wird der äußere Kanal durch einen schraubenförmig um ein inneres Rohr verlaufenden Steg bzw. durch ein äußeres Rohr, welches schraubenförmig um ein inneres Rohr gewickelt ist, gebidet.Similar devices are also known from U.S. Patents 3,952,230 and 4,324,230. The outer channel is bidided by a web extending helically around an inner tube or by an outer tube which is wound helically around an inner tube.
Der Erfindung liegt nun die Aufgabe zugrunde, ein Verfahren zum Erzeugen von solarem Dampf anzugeben, insbesondere in einem Turm- oder Dish-Kraftwerke, bei dem zugleich der Ge¬ samtwirkungsgrad des Solarkraftwerkes gesteigert und die Kosten für den Betrieb reduziert werden. Außerdem soll eine Vorrichtung zur Durchführung des Verfahrens angegeben werden.The invention is based on the object of specifying a method for generating solar steam, in particular in a tower or dish power plant, in which at the same time the overall efficiency of the solar power plant is increased and the operating costs are reduced. In addition, a device for performing the method is to be specified.
Die erstgenannte Aufgabe wird gemäß der Erfindung gelöst durch ein Verfahren zum Erzeugen von solarem Dampf mit minde¬ stens einem Receiverrohr, wobei das Receiverrohr wenigstens auf einem Teil seiner Länge von Wasser durchströmt wird und ein Teil des Wassers beim Durchströmen eine senkrecht zurThe first-mentioned object is achieved according to the invention by a method for generating solar steam with at least one receiver tube, wherein the receiver tube is flowed through by water at least over part of its length and part of the water flows through perpendicularly to it
Durchflußrichtung orientierte Geschwindigkeitskomponente er¬ hält.Direction of flow oriented velocity component.
Die zweitgenannte Aufgabe wird gemäß der Erfindung gelöst durch eine Vorrichtung zum Erzeugung von solarem Dampf, die mindestens einen Receiver mit mindestens einem Receiverrohr umfaßt, wobei das Receiverrohr von Wasser durchströmt wird, bei der Mittel vorgesehen sind, mit denen ein Teil des Was¬ sers beim Durchströmen des Receiverrohres eine senkrecht zur Durchflußrichtung orientierte Geschwindigkeitskomponente er¬ hält.The second-mentioned object is achieved according to the invention by a device for generating solar steam, which comprises at least one receiver with at least one receiver tube, water flowing through the receiver tube, in which means are provided with which part of the water in the Flow through the receiver tube receives a velocity component oriented perpendicular to the flow direction.
Die Geschwindigkeitskomponente senkrecht zur Durchflußrich¬ tung ermöglicht es, daß beim Betreiben des Solarkraftwerkes sich zu jedem Zeitpunkt auf der Innenseite des Receiverrohres ein Wasserfilm ausbildet und/oder erhalten bleibt. Somit kann eine Siedekrise und die dadurch bedingte Verschlechterung des Wärmeüberganges zwischen dem Material des Rohrmantels und dem das Receiverrohr durchströmenden Wärmeträgermediums, dem Was- ser, vermieden werden. Hierdurch wird der Gesamtwirkungsgrad des Solarkraftwerkes verbessert und zugleich erhöht sich die Lebensdauer des Receiverrohres. Aufgrund der längeren Lebens¬ dauer des Receiverrohres werden die Kosten für den Betrieb des Solarkraftwerkes, beispielsweise eines Turm- oder Dish- Kraftwerkes, reduziert. Vorzugsweise wird das Receiverrohr auf seiner gesamten Länge von Wasser durchströmt. Während des Betriebes des Solarkraft¬ werkes befindet sich in dem gesamten Receiverrohr teilweise Wasser oder Naßdampf und somit kein solarüberhitzter Dampf. Die Verwendung von Naßdampf als Betriebsmittel erweist sich als vorteilhaft gegenüber der Verwendung von solarüberhitztem Dampf. Naßdampf besteht zum einen Teil aus Dampf und zu einem weiteren Teil aus Wasser. Die Voraussetzung, daß ein Anteil von Wasser oder Naßdampf in dem gesamten Receiverrohr vorhan- den ist, ist eine notwendige Voraussetzung für die Erzeugung oder den Erhalt eines Wasserfilms auf der Innenseite des Re¬ ceiverrohres.The velocity component perpendicular to the flow direction enables a water film to form and / or be retained on the inside of the receiver tube at all times when the solar power plant is in operation. A boiling crisis and the consequent deterioration in the heat transfer between the material of the tube jacket and the heat transfer medium flowing through the receiver tube, the water, can thus be avoided. This improves the overall efficiency of the solar power plant and at the same time increases the service life of the receiver tube. Due to the longer service life of the receiver tube, the costs for operating the solar power plant, for example a tower or dish power plant, are reduced. The entire length of the receiver tube is preferably flowed through by water. During the operation of the solar power plant, there is partially water or wet steam in the entire receiver tube and therefore no solar superheated steam. The use of wet steam as an operating medium proves to be advantageous compared to the use of superheated steam. Wet steam consists partly of steam and partly water. The prerequisite that a portion of water or wet steam is present in the entire receiver tube is a necessary prerequisite for the generation or maintenance of a water film on the inside of the receiver tube.
Insbesondere wird das Wasser zum Einspeisen in die Receiver- röhre aus dem Wasserdampfkreislauf eines fossilbefeuertenIn particular, the water for feeding into the receiver tube is extracted from the steam cycle of a fossil-fueled one
Kraftwerkes entnommen. Da das Wasser nicht gesondert für das Solarkraftwerk zur Verfügung gestellt werden muß, werden zu¬ sätzliche Kosten an Betriebsmitteln eingespart.Taken from the power plant. Since the water does not have to be made available separately for the solar power plant, additional costs for operating resources are saved.
In einer weiteren Ausgestaltung ist auf der Innenseite derIn a further embodiment, the
Receiverrohre jeweils wenigstens eine Rippe angeordnet. Durch die Verwendung einer Innenberippung wird dem wärmeaufnehmen¬ dem Wasser ein zusätzlicher Drall aufgeprägt, wodurch der Wasserfilm auf der Innenseite der Receiverrohre auch bei sehr hohen Dampfgehalten des Naßdampfes, d.h. mit anderen Worten des solaren Dampfes, noch erhalten bleibt. Die Vorteile in- nenberippter Rohre beim Einsatz in der Bensondampferzeuger- technologie sind der Veröffentlichung "Verdampferkonzepte für Benson-Dampferzeuger, Heutiger Stand und neue Entwicklungen" von J.Franke et al. , VGB Kraftwerkstechnik 73, 1993, Heft 4, Seiten 352 - 361, zu entnehmen.Receiver tubes each arranged at least one rib. Through the use of internal fins, an additional swirl is imparted to the heat-absorbing water, as a result of which the water film on the inside of the receiver tubes also with very high steam contents of the wet steam, i.e. in other words the solar steam, is still preserved. The advantages of internally finned tubes when used in Benson steam generator technology are the publication "Evaporator concepts for Benson steam generators, current status and new developments" by J.Franke et al. , VGB Kraftwerkstechnik 73, 1993, Issue 4, pages 352 - 361.
Vorzugsweise ist die Rippe schraubenförmig angeordnet. Die schraubenförmige Anordnung der Rippe ermöglicht eine einfache technische Umsetzung. Insbesondere ist ein Steigungswinkel oc zwischen einer zur Rohrachse senkrechten Ebene und den Flanken der Rippe kleiner als 60°, vorzugsweise kleiner als 55 . Wärmeübergangsmessun¬ gen haben gezeigt, daß die Verbesserung des Wärmeüberganges bei diesen Steigungswinkeln α besonders ausgeprägt ist.The rib is preferably arranged helically. The helical arrangement of the rib enables simple technical implementation. In particular, a pitch angle oc between a plane perpendicular to the tube axis and the flanks of the rib is less than 60 °, preferably less than 55. Heat transfer measurements have shown that the improvement in heat transfer is particularly pronounced at these gradient angles α.
In einer weiteren Ausgestaltung sind die Receiverrohre paral¬ lel zueinander angeordnet.In a further embodiment, the receiver tubes are arranged parallel to one another.
Vorzugsweise sind die Receiverrohre miteinander verschweißt und in einer Ebene angeordnet. Dadurch wird eine dichte Packung der Receiverrohre ermöglicht, was wiederum eine Er¬ höhung des Gesamtwirkungsgrades des Solarkraftwerkes zur Fol¬ ge hat.The receiver tubes are preferably welded to one another and arranged in one plane. This enables the receiver tubes to be packed tightly, which in turn results in an increase in the overall efficiency of the solar power plant.
In einer weiteren Ausgestaltung sind die Receiverrohre durch Stege voneinander getrennt. Durch die Verwendung von Stegen, die die Receiverrohre voneinander trennen, wird die Absorp¬ tionsfläche für die einfallende Sonnenstrahlung vergrößert.In a further embodiment, the receiver tubes are separated from one another by webs. The use of webs which separate the receiver tubes from one another increases the absorption area for the incident solar radiation.
Zur weiteren Erläuterung der Erfindung wird auf die Ausfüh¬ rungsbeispiele der Zeichnung verwiesen. Es zeigen FIG 1 bis FIG 3 Vorrichtungen zum Erzeugen von solarem Dampf in schema¬ tischen Darstellungen.To further explain the invention, reference is made to the exemplary embodiments of the drawing. 1 to 3 show devices for generating solar steam in schematic representations.
Gemäß FIG 1 umfaßt eine Vorrichtung zum Erzeugen von solarem Dampf einen Receiver 2 mit einem Receiverrohr 4. Die Vorrich¬ tung ist dabei Teil eines Solarkraftwerkes, beispielsweise eines Turm- oder Dish-Kraftwerkes.According to FIG. 1, a device for generating solar steam comprises a receiver 2 with a receiver tube 4. The device is part of a solar power plant, for example a tower or dish power plant.
Das Receiverrohr 4 wird dabei von dem Wärmeträgermedium, bei¬ spielsweise Wasser, in Durchflußrichtung 6 wenigstens auf ei¬ nem Teil seiner Länge durchströmt. Auf der Innenseite 10 deε Receiverrohres 4 sind sechs Rippen 12 schraubenförmig ange- ordnet. Jeweilε zwei benachbarte Rippen 12 begrenzen einen Kanal 18. Beim Betrieb deε Solarkraftwerkeε wird daε Wasser, daß das Receiverrohr 4 durchströmt, nach dem Prinzip der Direktver¬ dampfung verdampft und somit im Receiverrohr 4 solarer Dampf erzeugt. Zugleich wird dem Receiverrohr 4 jedoch soviel Was- εer, beispielsweise aus dem Wasεerdampfkreislauf eines fos- εilbefeuerten Kraftwerkes, zugeführt, daß zu jedem Zeitpunkt des Betriebes in dem Receiverrohr 4 trotz der Verdampfung stets ein Anteil von Wasser vorhanden ist. Dadurch entsteht Naßdampf, d.h. daß im Receiverrohr 4 zugleich Dampf und Was- ser vorhanden ist.The heat transfer medium, for example water, flows through the receiver tube 4 in the flow direction 6 at least over part of its length. Six ribs 12 are arranged helically on the inside 10 of the receiver tube 4. Two adjacent ribs 12 delimit a channel 18. When the solar power plants are operated, the water that flows through the receiver tube 4 is evaporated according to the principle of direct evaporation and thus solar steam is generated in the receiver tube 4. At the same time, however, as much water is supplied to the receiver tube 4, for example from the water vapor cycle of a fossil-fired power plant, that a portion of water is always present in the receiver tube 4 at all times during operation, despite the evaporation. This produces wet steam, ie steam and water are present in the receiver tube 4 at the same time.
Der Anteil des Wassers der in den Kanälen 18 strömt erhält dabei durch die Rippen 12 einen zusätzlichen Drall, d.h. das Wasser erhält teilweise eine Geschwindigkeitskomponente senk- recht zur Durchflußrichtung 6. In dem Receiverrohr 4 sind so¬ mit Anteile von Wasser vorhanden, die jeweils in verschiedene Richtungen strömen. Dieser Effekt wird auch bereits bei Ver¬ wendung nur einer Rippe 12 erzielt.The proportion of the water flowing in the channels 18 receives an additional swirl through the ribs 12, i.e. some of the water receives a speed component perpendicular to the direction of flow 6. In the receiver tube 4 there are thus portions of water which each flow in different directions. This effect is also achieved when only one rib 12 is used.
Die Flanken 30 der Rippen 12 schließen mit einer zur Rohr¬ achse 30 senkrechten Ebene 32 einen Steigungswinkel oc ein. Dieser Steigungswinkel α iεt dabei kleiner 60 auεgeführt. In einer nicht weiter dargeεtellten Ausführungsform ist er klei¬ ner alε 55 , beispielsweise 50 . Dadurch wird ermöglicht, daß zu jedem Zeitpunkt deε Betriebeε auf der Innenεeite 10 des Receiverrohres 4 ein Wasserfilm entsteht oder erhalten bleibt. Demzufolge wird eine Siedekrise auf der Innenseite 10 des Receiverrohreε 4 vermieden und der Wärmeübergang zwiεchen dem Rohrmantel 20 des Receiverrohres 4 und dem im Receiver- röhr 4 strömenden Wasserε verbeεsert.The flanks 30 of the ribs 12 enclose a pitch angle oc with a plane 32 perpendicular to the tube axis 30. This pitch angle α is less than 60. In an embodiment that is not further illustrated, it is smaller than 55, for example 50. This enables a water film to form or remain on the inside 10 of the receiver tube 4 at all times during operation. Accordingly, a boiling crisis on the inside 10 of the receiver tube 4 is avoided and the heat transfer between the tube jacket 20 of the receiver tube 4 and the water flowing in the receiver tube 4 is improved.
Gemäß FIG 2 werden mehrere Receiverrohre 4 deε Receiverε 2 miteinander verεchweißt und in einer Ebene angeordnet. Dabei werden die Rohrmäntel 20 der Receiverrohre 4 durch Schweiß- nähte 24, die parallel zu den Längεwülsten 28 angeordnet sind, unmittelbar aneinandergeschweißt. Die Längswülεte 28 sind Teil der Receiverrohre 4 und erleichtern das Zusammen- schweißen der Receiverrohre 4. Die verschweißten Receiver¬ rohre 4 bilden in dieser Anordnung eine Rohrwand 14. In die¬ ser Rohrwand 14 sind die Receiverrohre 4 dichtgepackt, d.h. daß bei einem vorgegebenen Rohrdurchmesser der Receiverrohre 4 in dieser Rohrwand 14 die größtmögliche Menge von dem Wär¬ meträgermedium Wasεer durch den Receiver 2 fließt.According to FIG. 2, several receiver tubes 4 of the receiver 2 are welded together and arranged in one plane. The pipe jackets 20 of the receiver pipes 4 are welded directly to one another by welds 24, which are arranged parallel to the longitudinal beads 28. The longitudinal beads 28 are part of the receiver tubes 4 and facilitate the assembly welding the receiver tubes 4. In this arrangement, the welded receiver tubes 4 form a tube wall 14. In this tube wall 14, the receiver tubes 4 are packed tightly, ie that for a given tube diameter the receiver tubes 4 in this tube wall 14 contain the greatest possible amount of heat ¬ medium medium water flows through the receiver 2.
Gemäß der Vorrichtung in FIG 3 sind in der Rohrwand 14 zwi¬ schen den Receiverrohren 4 Stege 16 angeordnet. Diese Stege 16, beispielsweise aus demεelben Werkεtoff wie die Receiver¬ rohre 4, sind mit den Receiverrohren 4 durch Schweißnähte 24 verbunden. Die Stege 16 vergrößern die Absorptionsfläche für die einfallende Sonnenstrahlung. Die Wärme der von den Stegen absorbierten Sonnenstrahlung wird an die Receiverrohre 4 über die Schweißnähte 24 weitergeleitet. According to the device in FIG. 3, webs 16 are arranged in the tube wall 14 between the receiver tubes 4. These webs 16, for example made of the same material as the receiver tubes 4, are connected to the receiver tubes 4 by welds 24. The webs 16 enlarge the absorption area for the incident solar radiation. The heat of the solar radiation absorbed by the webs is passed on to the receiver tubes 4 via the weld seams 24.

Claims

Patentansprüche claims
1. Verfahren zum Erzeugen von solarem Dampf mit mindestens einem Receiverrohr (4), wobei das Receiverrohr (4) wenigstenε auf einem Teil seiner Länge von Wasser durchströmt wird und ein Teil des Wassers beim Durchströmen eine senkrecht zur Durchflußrichtung (6) orientierte Geschwindigkeitskomponente erhält.1. A method for generating solar steam with at least one receiver tube (4), wherein the receiver tube (4) is flowed through at least part of its length by water and part of the water receives a velocity component perpendicular to the flow direction (6) when flowing through.
2. Verfahren nach Anspruch 1, bei dem das Receiverrohr (4) auf seiner gesamten Länge von Waεεer durchströmt wird.2. The method according to claim 1, wherein the receiver tube (4) is flowed through over its entire length of water.
3. Verfahren nach Anspruch 1 oder 2, bei dem daε Waεεer zum Einspeisen in die Receiverrohre (4) aus dem Wasεer-Dampf- Kreislauf eines fossil befeuerten Kraftwerkes entnommen wird.3. The method according to claim 1 or 2, in which the water for feeding into the receiver tubes (4) is removed from the water / steam cycle of a fossil-fired power plant.
4. Vorrichtung zum Erzeugung von solarem Dampf, die minde¬ stens einen Receiver (2) mit mindeεtenε einem Receiverrohr (4) umfaßt, wobei das Receiverrohr (4) von Waεser durchεtrömt wird, bei der Mittel vorgeεehen εind, mit denen ein Teil deε Wassers beim Durchströmen des Receiverrohres (4) eine senk¬ recht zur Durchflußrichtung (6) orientierte Geschwindigkeits¬ komponente erhält.4. Device for generating solar steam, which comprises at least one receiver (2) with at least one receiver tube (4), the receiver tube (4) being flowed through by water, with which means are provided with which a part of the water receives a velocity component oriented perpendicular to the direction of flow (6) when flowing through the receiver tube (4).
5. Vorrichtung nach Anspruch 4, bei der auf der Innenseite5. The device according to claim 4, in which on the inside
(10) des Receiverrohres (4) wenigstens eine Rippe (12) ange¬ ordnet ist.(10) of the receiver tube (4) is arranged at least one rib (12).
6. Vorrichtung nach Anεpruch 5, bei der die Rippe (12) schraubenförmig angeordnet ist.6. Device according to claim 5, in which the rib (12) is arranged helically.
7. Vorrichtung nach Anspruch 6, bei der ein Steigungswinkel α zwischen einer zur Rohrachse (30) senkrechten Ebene (32) und den Flanken (34) der Rippe (12) kleiner als 60°, vorzugεweise kleiner als 55° ist. 7. The device according to claim 6, wherein a pitch angle α between a plane perpendicular to the tube axis (30) and the flanks (34) of the rib (12) is less than 60 °, preferably less than 55 °.
8. Vorrichtung nach einem der Ansprüche 5, 6 oder 7, bei der mehrere Receiverrohre (4) parallel zueinander angeordnet sind.8. Device according to one of claims 5, 6 or 7, in which a plurality of receiver tubes (4) are arranged parallel to one another.
9. Vorrichtung nach Anspruch 8, bei der die Receiverrohre (4) miteinander verschweißt und in einer Ebene angeordnet sind.9. The device according to claim 8, wherein the receiver tubes (4) are welded together and arranged in one plane.
10. Vorrichtung nach Anspruch 8, bei der die Receiverrohre (4) durch Stege (16) voneinander getrennt sind. 10. The device according to claim 8, wherein the receiver tubes (4) are separated from one another by webs (16).
PCT/DE1996/001887 1995-10-17 1996-10-01 Method and device for producing solar steam WO1997014930A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19538673.6 1995-10-17
DE19538673 1995-10-17

Publications (2)

Publication Number Publication Date
WO1997014930A2 true WO1997014930A2 (en) 1997-04-24
WO1997014930A3 WO1997014930A3 (en) 1997-07-31

Family

ID=7775096

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DE1996/001887 WO1997014930A2 (en) 1995-10-17 1996-10-01 Method and device for producing solar steam

Country Status (2)

Country Link
MA (1) MA23989A1 (en)
WO (1) WO1997014930A2 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2112441A2 (en) * 2008-04-21 2009-10-28 Joma-Polytec Kunststofftechnik GmbH Solar absorber and corresponding solar collector
WO2009129167A3 (en) * 2008-04-16 2010-06-24 Alstom Technology Ltd A solar steam generator
WO2012028514A3 (en) * 2010-09-03 2012-06-21 Siemens Aktiengesellschaft Solar-thermal absorber for direct evaporation, in particular in a solar tower power station
DE102010040208B4 (en) * 2010-09-03 2012-08-16 Siemens Aktiengesellschaft Solar thermal continuous evaporator heating surface with local cross-sectional constriction at its inlet
WO2012110341A1 (en) * 2011-02-17 2012-08-23 Siemens Aktiengesellschaft Solar collector comprising internally ribbed tubes
WO2012028492A3 (en) * 2010-09-03 2014-04-03 Siemens Aktiengesellschaft Solar-thermal absorber for direct evaporation, in particular in a solar tower power station

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2800439A1 (en) * 1978-01-05 1979-07-12 Spilling Heinz Dipl Ing Solar heat collector - with swirling device keeping absorber tune wall wetted by circulating fluid
FR2438804A1 (en) * 1978-10-10 1980-05-09 Babcock & Wilcox Co SOLAR BOILER
EP0503116A1 (en) * 1991-03-13 1992-09-16 Siemens Aktiengesellschaft Tube with a plurality of spiral ribs on his internal wall and steam generator using the same
DE4126038A1 (en) * 1991-08-06 1993-02-11 Siemens Ag Gas and steam turbine plant with solar heated steam generator - has additional combustion chamber in exhaust gas line from gas turbine
DE4331784A1 (en) * 1993-09-18 1995-03-23 Deutsche Forsch Luft Raumfahrt Trough collector

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2800439A1 (en) * 1978-01-05 1979-07-12 Spilling Heinz Dipl Ing Solar heat collector - with swirling device keeping absorber tune wall wetted by circulating fluid
FR2438804A1 (en) * 1978-10-10 1980-05-09 Babcock & Wilcox Co SOLAR BOILER
EP0503116A1 (en) * 1991-03-13 1992-09-16 Siemens Aktiengesellschaft Tube with a plurality of spiral ribs on his internal wall and steam generator using the same
DE4126038A1 (en) * 1991-08-06 1993-02-11 Siemens Ag Gas and steam turbine plant with solar heated steam generator - has additional combustion chamber in exhaust gas line from gas turbine
DE4331784A1 (en) * 1993-09-18 1995-03-23 Deutsche Forsch Luft Raumfahrt Trough collector

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
FORSCHUNGSVERBUND SONNENENERGIE: "THEMEN 93/94", DE, Seiten 57-64, XP000647082 M. M]LLER UND K. HENNECKE: "Solare Farmkraftwerke und Direktverdampfung in Parabolrinnen-Kollektoren" *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009129167A3 (en) * 2008-04-16 2010-06-24 Alstom Technology Ltd A solar steam generator
CN102046969A (en) * 2008-04-16 2011-05-04 阿尔斯托姆科技有限公司 A solar steam generator
US8607567B2 (en) 2008-04-16 2013-12-17 Alstom Technology Ltd Solar steam generator
EP2112441A2 (en) * 2008-04-21 2009-10-28 Joma-Polytec Kunststofftechnik GmbH Solar absorber and corresponding solar collector
EP2112441A3 (en) * 2008-04-21 2012-06-06 Joma-Polytec GmbH Solar absorber and corresponding solar collector
WO2012028514A3 (en) * 2010-09-03 2012-06-21 Siemens Aktiengesellschaft Solar-thermal absorber for direct evaporation, in particular in a solar tower power station
DE102010040208B4 (en) * 2010-09-03 2012-08-16 Siemens Aktiengesellschaft Solar thermal continuous evaporator heating surface with local cross-sectional constriction at its inlet
WO2012028492A3 (en) * 2010-09-03 2014-04-03 Siemens Aktiengesellschaft Solar-thermal absorber for direct evaporation, in particular in a solar tower power station
WO2012110341A1 (en) * 2011-02-17 2012-08-23 Siemens Aktiengesellschaft Solar collector comprising internally ribbed tubes
DE102011004266A1 (en) * 2011-02-17 2012-08-23 Siemens Aktiengesellschaft Solar panel with internally ribbed pipes

Also Published As

Publication number Publication date
WO1997014930A3 (en) 1997-07-31
MA23989A1 (en) 1997-07-01

Similar Documents

Publication Publication Date Title
DE2631196C3 (en) Solar heated boiler
EP1820965A1 (en) Method and device to control the energy production in a solar thermal power plant
WO2011104325A2 (en) Apparatus and method for generating superheated steam using solar energy on the basis of the forced flow concept, and use of the superheated steam
WO1997014930A2 (en) Method and device for producing solar steam
DE102011004266A1 (en) Solar panel with internally ribbed pipes
EP0720714A1 (en) Steam boiler of once-through type and process for operating the same
DE2935889A1 (en) STEAM GENERATOR
WO1997014887A1 (en) Energy-generation process and power station for carrying out the process
DE102010040208B4 (en) Solar thermal continuous evaporator heating surface with local cross-sectional constriction at its inlet
DE10056077A1 (en) Determination of the surface properties of a solar-powered steam generating parabolic mirror, so that misalignments can be corrected to ensure maximum operating efficiency
WO2012028512A2 (en) Solar-thermal once-through steam generator for direct evaporation, in particular in a solar-tower power plant
DE102010040206A1 (en) Solar thermal absorber for direct evaporation, especially in a solar tower power plant
DE3226167C2 (en) Solar energy conversion plant
DE102009026546B4 (en) solar panel
DE4406365A1 (en) Purifcn. of salt water by distn. in container-transportable solar still
WO2012028517A2 (en) Solar-thermal continuous flow evaporator
WO2011138213A2 (en) Solar thermal forced-flow steam generator with internally-ribbed tubes
EP2600058A1 (en) Device for converting a liquid work medium into a gas or vapor state, in particular for generating water steam
WO2012028514A2 (en) Solar-thermal absorber for direct evaporation, in particular in a solar tower power station
WO2012156350A2 (en) Steam generator, in particular for a solar thermal power plant
EP2497987A1 (en) Flexible steam conduit, particularly for solar thermal power plants
DE69129372T2 (en) DEVICE FOR PROTECTING CONDENSER TUBES
WO1998038457A1 (en) Solar power station, specially a solar power station with parabolic troughs
DE102010040199A1 (en) Solar thermal evaporation evaporator
DE2850285A1 (en) Solar heat collector plant - with preheating type in series with high-temp. type of collector

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): CN IL MX US

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
AK Designated states

Kind code of ref document: A3

Designated state(s): CN IL MX US

AL Designated countries for regional patents

Kind code of ref document: A3

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase