WO2015118256A1 - Linear-concentration solar power plant having a secondary reflector - Google Patents
Linear-concentration solar power plant having a secondary reflector Download PDFInfo
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- WO2015118256A1 WO2015118256A1 PCT/FR2015/050248 FR2015050248W WO2015118256A1 WO 2015118256 A1 WO2015118256 A1 WO 2015118256A1 FR 2015050248 W FR2015050248 W FR 2015050248W WO 2015118256 A1 WO2015118256 A1 WO 2015118256A1
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- WIPO (PCT)
- Prior art keywords
- glass
- receiver
- shell
- cellular glass
- mirror
- Prior art date
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S23/00—Arrangements for concentrating solar-rays for solar heat collectors
- F24S23/70—Arrangements for concentrating solar-rays for solar heat collectors with reflectors
- F24S23/77—Arrangements for concentrating solar-rays for solar heat collectors with reflectors with flat reflective plates
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- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S23/00—Arrangements for concentrating solar-rays for solar heat collectors
- F24S23/70—Arrangements for concentrating solar-rays for solar heat collectors with reflectors
- F24S23/79—Arrangements for concentrating solar-rays for solar heat collectors with reflectors with spaced and opposed interacting reflective surfaces
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S23/00—Arrangements for concentrating solar-rays for solar heat collectors
- F24S23/70—Arrangements for concentrating solar-rays for solar heat collectors with reflectors
- F24S23/80—Arrangements for concentrating solar-rays for solar heat collectors with reflectors having discontinuous faces
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S23/00—Arrangements for concentrating solar-rays for solar heat collectors
- F24S23/70—Arrangements for concentrating solar-rays for solar heat collectors with reflectors
- F24S23/82—Arrangements for concentrating solar-rays for solar heat collectors with reflectors characterised by the material or the construction of the reflector
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S80/00—Details, accessories or component parts of solar heat collectors not provided for in groups F24S10/00-F24S70/00
- F24S80/60—Thermal insulation
- F24S80/65—Thermal insulation characterised by the material
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S23/00—Arrangements for concentrating solar-rays for solar heat collectors
- F24S23/70—Arrangements for concentrating solar-rays for solar heat collectors with reflectors
- F24S2023/87—Reflectors layout
- F24S2023/872—Assemblies of spaced reflective elements on common support, e.g. Fresnel reflectors
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- 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
Definitions
- the present invention relates to a linear concentration solar power plant and more particularly to a receiver for such a linear concentration solar power station.
- thermal solar power plants that are an alternative to power plants operating from fossil fuels such as oil or coal for example.
- the four main types of plants are parabolic trough plants, tower plants, parabolic trough plants and Fresnel solar mirrors.
- the cylindro-parabolic collector plants consist of parallel rows of long cylindro-parabolic mirrors that rotate around a horizontal axis to follow the course of the sun.
- the sun's rays are concentrated on a horizontal absorber tube, in which circulates a coolant whose temperature generally reaches 400 ° C. This fluid is then pumped through exchangers to produce superheated steam that drives a turbine or electric generator.
- Tower solar power plants consist of numerous mirrors concentrating the sun's rays towards a boiler located at the top of a tower.
- the uniformly distributed mirrors are called primary reflectors.
- Each primary reflector is orientable, and follows the sun individually and reflects it precisely towards the receiver at the top of the solar tower.
- the concentration factor can exceed 1000, which makes it possible to reach high temperatures, from 600 ° C to 1000 ° C.
- energy concentrated on the receiver is then either directly transferred to a thermodynamic fluid to generate steam driving a turbine or to heat air supplying a gas turbine, or used to heat an intermediate heat transfer fluid.
- This heat transfer fluid is then sent to a boiler and the steam generated drives turbines. In all cases, the turbines drive alternators producing electricity.
- parabolic power plants In parabolic power plants, the latter operate autonomously. They automatically orient themselves and follow the sun on two axes in order to reflect and concentrate the sun's rays towards a point of convergence called focus usually consisting in a closed chamber containing gas which is raised in temperature under the effect of the concentration. . This drives a Stirling engine that converts solar thermal energy into mechanical energy and then electricity.
- concentration ratio of this system is often greater than 2000 and the receiver can reach a temperature of 1000 ° C.
- the least expensive solar power plants consist of solar power plants called Fresnel mirrors. Indeed, the latter are similar to cylindro-parabolic collector plants with the exception that the cylindro-parabolic collectors, which are expensive to manufacture, are replaced by a succession of flat mirrors which approximates the parabolic form of the collector.
- Each of the mirrors can be rotated by tracking the sun's course to continuously redirect and focus the sun's rays to a tube or set of fixed linear receiver tubes. While circulating in this horizontal receiver, the thermodynamic fluid can be vaporized and then superheated up to 500 ° C. The steam then produced drives a turbine that produces electricity.
- the thermodynamic cycle is usually direct, which avoids heat exchangers.
- a linear concentration solar power plant comprises a set of mirror modules constituting so-called primary reflectors, in this case Fresnel mirrors, mounted on a frame integral with the ground so that said mirrors extend in parallel, each line of mirrors comprising a series of several mirrors.
- This plant also comprises a linear receiver supported by a series of poles extending vertically from the central part of the frame so that the linear receiver extends longitudinally above the mirrors which are oriented to reflect and focus solar radiation. to the linear receiver.
- Said linear receiver generally consists of one or more parallel longiline tubes in each of which circulates a coolant, such as for example water, brought to the vapor state by the focusing of the solar radiation on each tube by the mirrors .
- a coolant such as for example water
- the linear receiver receives solar radiation energy in radiative form and converts it into heat energy, which may be used as heat or to generate electricity from a turbo-alternator assembly.
- the international patent application WO 2012/156624 describes a solar installation with linear concentration and a receiver that can be used in such an installation.
- the installation is characterized in that at least one absorber tube is supported on each of the masts, independently of the secondary receiver, by means of an anti-friction plate secured to the mast transversely to the tube. absorber which is bilaterally held on the antifriction plate while resting in a notch of this plate.
- the linear receiver is carried by the metal frame and comprises a so-called secondary reflector consisting of folded metal elements, polished and coated to ensure good reflectivity.
- This secondary reflector extending above the tube in which the coolant circulates, allows overconcentration of a portion of the radiation from the primary concentration system.
- the receiver also has thermal insulation that limits heat loss from the system.
- the thermal insulation consists of rock wool or glass wool which is inserted into a metal box also ensuring the rigidity and tightness of the system.
- One of the aims of the invention is therefore to overcome these disadvantages by providing a receiver of simple and inexpensive design, having constant reflective properties by greatly limiting the expansion of said reflector in particular.
- a linear concentration solar power plant comprising a set of so-called primary reflectors, such as Fresnel mirrors, integral with a frame and oriented to reflect and focus the solar radiation to a receiver extending longitudinally at the top of vertical mats integral with said frame, said receiver comprising at least one absorber tube in which circulates a coolant, a secondary reflector extending above the absorber tube parallel to the latter so as to concentrate towards the solar radiation absorber tube from the set of primary reflectors; said central unit is remarkable in that the secondary reflector consists of a plurality of substantially semicylindrical shells obtained in cellular glass, the concave wall of each cellular glass shell receiving a mirror.
- primary reflectors such as Fresnel mirrors
- Said mirror consists of a glass mirror whose rear face consists of a reflective silver layer.
- the receiver has anti-reflective windows closing the hemi-cylindrical hulls.
- Each hemi-cylindrical shell has on the concave wall a longitudinal groove near the free end of each branch of the hull, said grooves receiving the anti-reflective panes.
- the convex wall of the hemi-cylindrical shells is coated with a protective layer.
- the hemi-cylindrical shells are obtained in cellular glass having a density of between 110 and 165 kg / m 3.
- Said semicylindrical shells are obtained in cellular glass having a thermal conductivity of between 0.040 and 0.055 W / mK.
- Another object of the invention relates to a method of manufacturing a receiver of a linear concentration solar power plant according to the invention which is remarkable in that it comprises at least the following steps of:
- the formation of the cellular glass shell is obtained by molding.
- the formation of the cellular glass shell is obtained by cutting into a cell glass matrix.
- the method comprises a gravitational hot bending step of a glass mirror whose rear face consists of a reflective silver layer protected by sintered glass.
- the method comprises a step of forming longitudinal grooves on the concave wall of each shell, near the free end of each branch of the shell, said grooves receiving anti-reflective glass.
- Said cell glass has a density of between 110 and 165 kg / m3 and / or a thermal conductivity of between 0.040 and 0.055 W / mK.
- FIG. 1 is a perspective view of a linear concentration solar power plant according to the invention
- FIG. 2 is a perspective view of a collection field of the linear concentration solar power plant according to the invention
- FIG. 3 is a cross-sectional view of the receiver of the linear concentration solar power plant according to the invention.
- FIG. 4 is a cross-sectional view of an alternative embodiment of the receiver of the linear concentration solar power plant according to the invention.
- FIG. 5 is a cross-sectional view of a detail of the alternative embodiment of the receiver of the linear concentration solar power plant according to the invention.
- FIG. 6 is a perspective view of the anti-reflective canopy of the alternative embodiment of the receiver of the linear concentration solar power plant according to the invention.
- FIG. 7 is a view from above of the anti-reflective canopy of the variant embodiment of the receiver of the linear concentration solar power plant according to the invention.
- the solar thermal power station with linear concentration is of the Fresnel mirror type and comprises several solar concentration collection fields (1), a so-called production unit (2) comprising means for transforming the thermal energy in electricity for example.
- Each solar concentrating collection field (1) comprises a plurality of primary reflectors (3) integral with a metal frame (4) which concentrate the solar rays on an absorber tube (5) in which a coolant circulates, said coolant consisting of a fluid such as water or a gas such as air for example.
- Said absorber tube (5) extends into a receiver (6) secured to the upper ends of vertical mats (7) carried by the frame (4) as will be detailed a little further.
- the term "primary reflector” means a device for tracking the course of the sun for direct sunlight all the day to the absorber tube (5) using mirrors.
- the plane mirrors (3) are articulated to the frame (4) so as to approximate a parabolic shape.
- each of the mirrors can rotate following the path of the sun to redirect and constantly focus the sunlight to the tube (5).
- the receiver (6) consists of a plurality of substantially semicylindrical shells (8) obtained in cellular glass, the concave wall of each cellular glass shell (8) receiving a mirror (9). ).
- Said mirror (9) consists of a glass mirror whose rear face consists of a reflective silver layer.
- Said semi-cylindrical shells (8) are obtained in cellular glass preferably having a density of between 10 and 165 kg / m3 and a thermal conductivity of between 0.040 and 0.055 W / mK.
- the formation of each cellular glass shell (8) is obtained by molding or by cutting in a cellular glass matrix.
- Said mirror (9) is preferably obtained by gravitational hot bending of a glass mirror whose rear face consists of a reflective silver layer protected by sintered glass.
- Said mirror (9) may, for example, consist of a mirror as described in US Pat. No. 8,585,225 filed by Guardian Industries or in any equivalent mirror.
- the receiver (6) has anti-reflective panes (10) closing the hemi-cylindrical shells (8).
- each hemi-cylindrical shell (8) comprises on the concave wall a longitudinal groove (11) near the free end of each branch of the shell (8), said grooves (11) receiving the longitudinal edges of the anti-reflective glass (10).
- the convex wall of the hemi-cylindrical shells (8) is coated with a protective layer.
- This protective layer may consist, for example, in an aluminum foil, similar to the aluminum foils used for the heat insulation of tubes, bonded to the convex wall of said semi-cylindrical shells (8) or in a layer of a self-adhesive sealing material called Terostat® and marketed by Foamglas.
- Terostat® a self-adhesive sealing material
- the insulating shells including secondary reflectors and windows, are simply placed on brackets (12) which are secured to the upper end of the mats (7), which facilitates their initial placement and their possible replacement .
- the receiver (6) consists of a plurality of substantially semicylindrical shells (8) obtained in cellular glass, the concave wall each cellular glass shell (8) receiving a mirror (9).
- Said mirror (9) consists of a glass mirror whose rear face consists of a reflective silver layer.
- Said hemi-cylindrical hulls (8) are obtained in cellular glass preferably having a density of between 110 and 165 kg / m 3 and a thermal conductivity of between 0.040 and 0.055 W / m 2.
- the formation of each cellular glass shell (8) is obtained by molding or by cutting in a cellular glass matrix.
- Said mirror (9) is preferably obtained by gravitational hot bending of a glass mirror whose rear face consists of a reflective silver layer protected by glass obtained by sintering.
- Said mirror (9) may, for example, consist of a mirror as described in US Pat. No. 8,585,225 filed by Guardian Industries or in any equivalent mirror.
- Said receiver (6) comprises stiffeners (13) extending on either side of the semi-cylindrical shells (8), said stiffeners (13) consisting of L-shaped parts whose branches are respectively integral with the outer wall semi-cylindrical shells (8) and the free edge of said shells (8). It also comprises second U-shaped stiffeners (14) whose branches are folded inwards and are integral with the first stiffener (13), said second stiffeners (14) being secured to the upper end of the mats (7). ) by means of bolts (15).
- the absorber tube (5) extends into the receiver (6) while resting on a support (16) integral with the upper end of the mat (7).
- Said support (16) consists of a roller (17) having a cylindrical central body (18) provided with an annular groove (19) so that the contact surface of the absorber tube (5) on the annular groove (19) the roller (17) is reduced to two points and the shafts (20) mounted free to rotate in slots in the legs (21) of a stirrup (22) generally U-shaped.
- the coefficient friction between the axes (20) of the roller (17) and the stirrup (22) is less than or equal to the coefficient of friction between the roller (17) and the absorber tube (5).
- the roller (17) and its axes (20) and the stirrup (22) are made of stainless steel and / or alumina silicate.
- the annular groove (19) has a section of substantially trapezoidal shape comprising a flat bottom (23) and two inclined walls (24) on either side of said bottom (23);
- the annular groove (19) may have a substantially semi-circular section whose concavity has a radius of curvature less than the radius of curvature of the absorber tube (5) without departing from the scope of the invention .
- the invention thus has many advantages.
- the small contact area between the roller (17) and the absorber tube (5) limits the frictional forces between said tube (5) and the roller (17). This low friction reduces the wear of the thin selective layer of the tube (5) during its expansion.
- the rotation of the roller allows the free longitudinal expansion of the tube (5).
- the absorber tube (5) is irradiated by the concentrated radiation of the sun; the more the temperature of its selective layer is hot, the more it is sensitive to abrasion.
- a coolant circulates inside the tube (5), which generates a temperature gradient along its longitudinal axis.
- the receiver (6) also comprises anti-reflective glasses (10) extending between two mats (7) under the absorber tube (5).
- Said anti-reflective glasses (10) are carried by a metal frame (25) substantially rectangular and whose ends are provided with a shoulder (26) adapted to be secured to the upper end of the mats (7).
- the metal frame (25) is obtained from generally L-shaped metal profile, the base of the L forming a shoulder on which the anti-reflective panes (10) resting, whose edges are provided with an expansion joint and sealing (27).
- the same metal frame (25) supports a plurality of anti-reflective panes (10) joined in pairs by an expansion and sealing joint (27).
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Abstract
The present invention relates to a linear-concentration solar power plant including a set of reflectors, referred to as primary reflectors, such as Fresnel mirrors, which are rigidly connected to a frame and oriented such as to reflect and concentrate the solar radiation toward a receiver which extends longitudinally at the top of vertical masts which are rigidly connected to said frame, said receiver comprising at least one absorbing pipe in which a heat-transfer fluid flows, a secondary reflector extending above the absorbing pipe and parallel therewith, such as to concentrate the solar radiation from the set of primary reflectors toward the absorbing pipe; said power plant is characterised in that the secondary reflector consists of a plurality of substantially semi-cylindrical shells which are made of cellular glass, the concave wall of each cellular glass shell receiving a mirror.
Description
CENTRALE SOLAI RE A CONCENTRATI ON LI N ÉAI RE AVEC CENTRALE SOLAI RE HAS CONCENTRATI ON LI N EAR WITH
RÉFLECTEU R SECON DAI RE REFLECTIVE R SECON DAI RE
DOMAINE TECHNIQUE TECHNICAL AREA
La présente invention concerne une centrale solaire à concentration linéaire et plus particulièrement un récepteur pour une telle centrale solaire à concentration linéaire. ART ANTÉRIEUR The present invention relates to a linear concentration solar power plant and more particularly to a receiver for such a linear concentration solar power station. PRIOR ART
Dans le domaine de la production d'énergie, il est bien connu des centrales électriques solaires thermiques qui sont une alternative aux centrales électriques fonctionnant à partir d'énergies fossiles telles que le pétrole ou le charbon par exemple. In the field of energy production, it is well known thermal solar power plants that are an alternative to power plants operating from fossil fuels such as oil or coal for example.
Il existe plusieurs types de centrale électrique solaire thermique. Les quatre principaux types de centrale sont les centrales à collecteurs cylindro-paraboliques, les centrales à tour, les centrales à capteurs paraboliques et les centrales solaires à miroirs de Fresnel. There are several types of solar thermal power plant. The four main types of plants are parabolic trough plants, tower plants, parabolic trough plants and Fresnel solar mirrors.
Les centrales à collecteurs cylindro-paraboliques se composent de rangées parallèles de longs miroirs cylindro-paraboliques qui tournent autour d'un axe horizontal pour suivre la course du soleil. Les rayons solaires sont concentrés sur un tube absorbeur horizontal, dans lequel circule un fluide caloporteur dont la température atteint en général 400 °C. Ce fluide est ensuite pompé à travers des échangeurs afin de produire de la vapeur surchauffée qui actionne une turbine ou un générateur électrique. The cylindro-parabolic collector plants consist of parallel rows of long cylindro-parabolic mirrors that rotate around a horizontal axis to follow the course of the sun. The sun's rays are concentrated on a horizontal absorber tube, in which circulates a coolant whose temperature generally reaches 400 ° C. This fluid is then pumped through exchangers to produce superheated steam that drives a turbine or electric generator.
Les centrales solaires à tour sont constituées de nombreux miroirs concentrant les rayons solaires vers une chaudière située au sommet d'une tour. Les miroirs uniformément répartis sont appelés réflecteurs primaires. Chaque réflecteur primaire est orientable, et suit le soleil individuellement et le réfléchit précisément en direction du receveur au sommet de la tour solaire. Le facteur de concentration peut dépasser 1000, ce qui permet d'atteindre des températures importantes, de 600 °C à 1000 °C. L'énergie
concentrée sur le receveur est ensuite soit directement transférée à un fluide thermodynamique pour générer de la vapeur entraînant une turbine ou chauffer de l'air alimentant une turbine à gaz, soit utilisée pour chauffer un fluide caloporteur intermédiaire. Ce fluide caloporteur est ensuite envoyé dans une chaudière et la vapeur générée actionne des turbines. Dans tous les cas, les turbines entraînent des alternateurs produisant de l'électricité. Tower solar power plants consist of numerous mirrors concentrating the sun's rays towards a boiler located at the top of a tower. The uniformly distributed mirrors are called primary reflectors. Each primary reflector is orientable, and follows the sun individually and reflects it precisely towards the receiver at the top of the solar tower. The concentration factor can exceed 1000, which makes it possible to reach high temperatures, from 600 ° C to 1000 ° C. energy concentrated on the receiver is then either directly transferred to a thermodynamic fluid to generate steam driving a turbine or to heat air supplying a gas turbine, or used to heat an intermediate heat transfer fluid. This heat transfer fluid is then sent to a boiler and the steam generated drives turbines. In all cases, the turbines drive alternators producing electricity.
Dans les centrales à capteurs paraboliques, ces derniers fonctionnent d'une manière autonome. Ils s'orientent automatiquement et suivent le soleil sur deux axes afin de réfléchir et de concentrer les rayons du soleil vers un point de convergence appelé foyer consistant usuellement dans une enceinte fermée contenant du gaz qui est monté en température sous l'effet de la concentration. Cela entraîne un moteur Stirling qui convertit l'énergie solaire thermique en énergie mécanique puis en électricité. Le rapport de concentration de ce système est souvent supérieur à 2000 et le récepteur peut atteindre une température de 1000 °C. In parabolic power plants, the latter operate autonomously. They automatically orient themselves and follow the sun on two axes in order to reflect and concentrate the sun's rays towards a point of convergence called focus usually consisting in a closed chamber containing gas which is raised in temperature under the effect of the concentration. . This drives a Stirling engine that converts solar thermal energy into mechanical energy and then electricity. The concentration ratio of this system is often greater than 2000 and the receiver can reach a temperature of 1000 ° C.
Tous ces types de centrale présentent l'inconvénient d'être particulièrement onéreuses. Les centrales solaires les moins onéreuses consistent dans les centrales solaires dites à miroir de Fresnel. En effet, ces dernières sont similaires aux centrales à collecteurs cylindro-parabolique à l'exception du fait que les collecteurs cylindro-paraboliques, qui sont chers à fabriquer, sont substitués par une succession de miroirs plans qui approxime la forme parabolique du collecteur. Chacun des miroirs peut pivoter en suivant la course du soleil pour rediriger et concentrer en permanence les rayons solaires vers un tube ou un ensemble de tubes récepteurs linéaires fixes. En circulant dans ce récepteur horizontal, le fluide thermodynamique peut être vaporisé puis surchauffé jusqu'à 500 °C. La vapeur alors produite actionne une turbine qui produit de l'électricité. Le cycle thermodynamique est généralement direct, ce qui permet d'éviter les échangeurs de chaleur. All these types of plant have the disadvantage of being particularly expensive. The least expensive solar power plants consist of solar power plants called Fresnel mirrors. Indeed, the latter are similar to cylindro-parabolic collector plants with the exception that the cylindro-parabolic collectors, which are expensive to manufacture, are replaced by a succession of flat mirrors which approximates the parabolic form of the collector. Each of the mirrors can be rotated by tracking the sun's course to continuously redirect and focus the sun's rays to a tube or set of fixed linear receiver tubes. While circulating in this horizontal receiver, the thermodynamic fluid can be vaporized and then superheated up to 500 ° C. The steam then produced drives a turbine that produces electricity. The thermodynamic cycle is usually direct, which avoids heat exchangers.
Usuellement, une centrale solaire à concentration linéaire comprend un ensemble de modules de miroirs constituant des réflecteurs dits primaires, en l'espèce des miroirs de Fresnel, montés sur bâti solidaire du sol de telle sorte que lesdits miroirs s'étendent
parallèlement, chaque ligne de miroirs comprenant une série de plusieurs miroirs. Cette centrale comprend également un récepteur linéaire supporté par une série de mâts s 'étendant verticalement depuis la partie centrale du bâti de manière à ce que le récepteur linéaire s'étende longitudinalement au-dessus des miroirs qui sont orientés pour réfléchir et concentrer le rayonnement solaire vers le récepteur linéaire. Usually, a linear concentration solar power plant comprises a set of mirror modules constituting so-called primary reflectors, in this case Fresnel mirrors, mounted on a frame integral with the ground so that said mirrors extend in parallel, each line of mirrors comprising a series of several mirrors. This plant also comprises a linear receiver supported by a series of poles extending vertically from the central part of the frame so that the linear receiver extends longitudinally above the mirrors which are oriented to reflect and focus solar radiation. to the linear receiver.
Ledit récepteur linéaire est généralement constitué d'un ou plusieurs tubes longilignes parallèles dans chacun desquels circule un fluide caloporteur, tel que par exemple de l'eau, porté à l'état de vapeur par la focalisation du rayonnement solaire sur chaque tube par les miroirs. On notera que le nombre ainsi que la taille de chacun des tubes récepteurs sont déterminés d'une part en fonction des caractéristiques du fluide caloporteur et d'autre part en fonction de la géométrie des miroirs. Said linear receiver generally consists of one or more parallel longiline tubes in each of which circulates a coolant, such as for example water, brought to the vapor state by the focusing of the solar radiation on each tube by the mirrors . It will be noted that the number as well as the size of each of the receiver tubes are determined on the one hand as a function of the characteristics of the coolant and on the other hand as a function of the geometry of the mirrors.
Ledit récepteur linéaire reçoit l'énergie de rayonnement solaire sous forme radiative et la convertit en énergie thermique, qui peut être utilisée sous forme de chaleur ou pour produire de l'électricité à partir d'un ensemble turbo-alternateur. The linear receiver receives solar radiation energy in radiative form and converts it into heat energy, which may be used as heat or to generate electricity from a turbo-alternator assembly.
De telles centrales solaires à concentration solaire sont notamment décrites dans les demandes de brevet international WO 2009/029277 et WO 2012/156624. Such solar concentrating solar power plants are described in particular in international patent applications WO 2009/029277 and WO 2012/156624.
La demande de brevet international WO 2009/029277 décrit des exemples et des variantes de systèmes de capteur solaire comprenant un récepteur linéaire surélevé et des premiers et des seconds champs de réflecteur situés sur des côtés opposés du récepteur. Ces champs de réflecteur sont conçus et commandés pour réfléchir un rayonnement solaire sur le récepteur. Ce document décrit également des exemples et des variantes de récepteurs et de réflecteurs qui peuvent, dans certaines variantes, être utilisés dans lesdits systèmes de capteur solaire. International patent application WO 2009/029277 discloses examples and variants of solar collector systems comprising a raised linear receiver and first and second reflector fields located on opposite sides of the receiver. These reflector fields are designed and controlled to reflect solar radiation on the receiver. This document also describes examples and variants of receivers and reflectors which may, in certain variants, be used in said solar collector systems.
La demande de brevet international WO 2012/156624 décrit une installation solaire à concentration linéaire et un récepteur pouvant être utilisé dans une telle installation. Selon l'invention, l'installation est caractérisée en ce qu'au moins un tube absorbeur est supporté sur chacun des mâts, indépendamment du récepteur secondaire, par l'intermédiaire d'une plaque antifriction solidaire du mât transversalement au tube
absorbeur qui est bilatéralement maintenu sur la plaque antifriction en reposant dans une échancrure de cette plaque. The international patent application WO 2012/156624 describes a solar installation with linear concentration and a receiver that can be used in such an installation. According to the invention, the installation is characterized in that at least one absorber tube is supported on each of the masts, independently of the secondary receiver, by means of an anti-friction plate secured to the mast transversely to the tube. absorber which is bilaterally held on the antifriction plate while resting in a notch of this plate.
Dans toutes ces centrales solaires à concentration linéaire, le récepteur linéaire est porté par le bâti métallique et comporte un réflecteur dit secondaire constitué d'éléments en métal plié, poli et revêtu pour assurer une bonne réflectivité. Ce réflecteur secondaire, s 'étendant au-dessus du tube dans lequel circule le fluide caloporteur, permet la surconcentration d'une partie du rayonnement issu du système de concentration primaire. Le récepteur comporte également un isolant thermique qui limite les pertes de chaleur du système. Usuellement, l'isolant thermique consiste dans de la laine de roche ou de la laine de verre qui est insérée dans un caisson métallique assurant également la rigidité et l'étanchéité du système. In all these linear concentration solar power plants, the linear receiver is carried by the metal frame and comprises a so-called secondary reflector consisting of folded metal elements, polished and coated to ensure good reflectivity. This secondary reflector, extending above the tube in which the coolant circulates, allows overconcentration of a portion of the radiation from the primary concentration system. The receiver also has thermal insulation that limits heat loss from the system. Usually, the thermal insulation consists of rock wool or glass wool which is inserted into a metal box also ensuring the rigidity and tightness of the system.
Ainsi, toutes les solutions existantes nécessitent l'inclusion du récepteur dans un caisson métallique procurant un poids plus important de l'ensemble récepteur et, de ce fait, une charpente métallique dimensionnée en conséquence. Ce dimensionnement implique un coût significatif dans l'ensemble récepteur et provoque une ombre portée sur le système de concentration primaire, réduisant les performances optiques de ce dernier. Par ailleurs, la présence d'un caisson métallique entraîne de fortes dilatations qu'il est nécessaire de compenser en bout de ligne. En outre, les dilatations relatives entre les différents éléments peuvent provoquer la casse du matériel et donc des frais de maintenance. En effet, le métal utilisé pour le caisson se dilate beaucoup, le verre assez peu et l'isolant thermique quasiment pas. On notera que la ductilité de la tôle à haute température peut également engendrer une déformation du réflecteur secondaire qui réduit sa performance optique en modifiant son profil. Thus, all existing solutions require the inclusion of the receiver in a metal box providing a greater weight of the receiver assembly and, therefore, a metal frame dimensioned accordingly. This sizing involves a significant cost in the receiver assembly and causes a drop shadow on the primary focusing system, reducing the optical performance of the latter. In addition, the presence of a metal box causes large expansions that must be compensated at the end of the line. In addition, the relative expansions between the various elements can cause the breakage of the equipment and therefore maintenance costs. Indeed, the metal used for the box expands a lot, the glass quite little and the thermal insulation almost not. It should be noted that the ductility of the high temperature sheet can also cause deformation of the secondary reflector which reduces its optical performance by modifying its profile.
De plus, de hautes températures combinées à la présence d'air peuvent causer une oxydation du métal à la surface du réflecteur secondaire réduisant ainsi ses propriétés réfléchissantes et diminuant l'efficacité optique du système. In addition, high temperatures combined with the presence of air can cause oxidation of the metal on the surface of the secondary reflector thereby reducing its reflective properties and decreasing the optical efficiency of the system.
EXPOSE DE L'INVENTION
L'un des buts de l'invention est donc de remédier à ces inconvénients en proposant un récepteur de conception simple et peu onéreuse, présentant des propriétés réfléchissantes constantes en limitant fortement la dilatation dudit réflecteur notamment. SUMMARY OF THE INVENTION One of the aims of the invention is therefore to overcome these disadvantages by providing a receiver of simple and inexpensive design, having constant reflective properties by greatly limiting the expansion of said reflector in particular.
A cet effet et conformément à l'invention, il est proposé une centrale solaire à concentration linéaire comprenant un ensemble de réflecteurs dits primaires, tels que des miroirs de Fresnel, solidaires d'un bâti et orientés pour réfléchir et concentrer le rayonnement solaire vers un récepteur s 'étendant longitudinalement au sommet de mats verticaux solidaires dudit bâti, ledit récepteur comportant au moins un tube absorbeur dans lequel circule un fluide caloporteur, un réflecteur secondaire s 'étendant au-dessus du tube absorbeur parallèlement à ce dernier de manière à concentrer vers le tube absorbeur le rayonnement solaire issu de l'ensemble des réflecteurs primaires ; ladite centrale est remarquable en ce que le réflecteur secondaire est constitué d'une pluralité de coques sensiblement hémi-cylindrique obtenues dans du verre cellulaire, la paroi concave de chaque coque en verre cellulaire recevant un miroir. For this purpose and in accordance with the invention, it is proposed a linear concentration solar power plant comprising a set of so-called primary reflectors, such as Fresnel mirrors, integral with a frame and oriented to reflect and focus the solar radiation to a receiver extending longitudinally at the top of vertical mats integral with said frame, said receiver comprising at least one absorber tube in which circulates a coolant, a secondary reflector extending above the absorber tube parallel to the latter so as to concentrate towards the solar radiation absorber tube from the set of primary reflectors; said central unit is remarkable in that the secondary reflector consists of a plurality of substantially semicylindrical shells obtained in cellular glass, the concave wall of each cellular glass shell receiving a mirror.
Ledit miroir consiste en un miroir de verre dont la face arrière est constituée d'une couche d'argent réfléchissante. Said mirror consists of a glass mirror whose rear face consists of a reflective silver layer.
Par ailleurs, le récepteur comporte des vitres anti-réfléchissantes fermant les coques hémi-cylindriques . In addition, the receiver has anti-reflective windows closing the hemi-cylindrical hulls.
Chaque coque hémi-cylindrique comporte sur la paroi concave une gorge longitudinale à proximité de l'extrémité libre de chaque branche de la coque, lesdites gorges recevant les vitres anti-réfléchissantes. Each hemi-cylindrical shell has on the concave wall a longitudinal groove near the free end of each branch of the hull, said grooves receiving the anti-reflective panes.
De préférence, la paroi convexe des coques hémi-cylindriques est revêtue d'une couche de protection. Preferably, the convex wall of the hemi-cylindrical shells is coated with a protective layer.
De plus, les coques hémi-cylindriques sont obtenues dans du verre cellulaire présentant une masse volumique comprise entre 110 et 165 kg/m3.
Lesdites coques hémi- cylindriques sont obtenues dans du verre cellulaire présentant une conductivité thermique comprise entre 0,040 et 0,055 W/mK. In addition, the hemi-cylindrical shells are obtained in cellular glass having a density of between 110 and 165 kg / m 3. Said semicylindrical shells are obtained in cellular glass having a thermal conductivity of between 0.040 and 0.055 W / mK.
Un autre objet de l'invention concerne un procédé de fabrication d'un récepteur d'une centrale solaire à concentration linaire suivant l'invention remarquable en ce qu'il comporte au moins les étapes suivantes de : Another object of the invention relates to a method of manufacturing a receiver of a linear concentration solar power plant according to the invention which is remarkable in that it comprises at least the following steps of:
- formation d'au moins une coque sensiblement hémi-cylindrique dans une matrice de verre cellulaire, forming at least one substantially semicylindrical shell in a cellular glass matrix,
- d'assemblage d'un miroir sur la paroi concave de la coque hémi-cylindrique. - Assembling a mirror on the concave wall of the hemi-cylindrical shell.
De préférence, la formation de la coque en verre cellulaire est obtenue par moulage. Preferably, the formation of the cellular glass shell is obtained by molding.
Alternativement, la formation de la coque en verre cellulaire est obtenue par découpe dans une matrice de verre cellulaire. Alternatively, the formation of the cellular glass shell is obtained by cutting into a cell glass matrix.
Par ailleurs, le procédé comporte une étape de cintrage gravitaire à chaud d'un miroir en verre dont la face arrière est constituée d'une couche d'argent réfléchissante protégée par du verre obtenu par frittage. Accessoirement, le procédé comporte une étape de formation de gorges longitudinales sur la paroi concave de chaque coque, à proximité de l'extrémité libre de chaque branche de la coque, lesdites gorges recevant des vitres anti-réfléchissantes. Furthermore, the method comprises a gravitational hot bending step of a glass mirror whose rear face consists of a reflective silver layer protected by sintered glass. Incidentally, the method comprises a step of forming longitudinal grooves on the concave wall of each shell, near the free end of each branch of the shell, said grooves receiving anti-reflective glass.
Ledit verre cellulaire présente une masse volumique comprise entre 110 et 165 kg/m3 et/ou une conductivité thermique comprise entre 0,040 et 0,055 W/mK. Said cell glass has a density of between 110 and 165 kg / m3 and / or a thermal conductivity of between 0.040 and 0.055 W / mK.
DESCRIPTION SOMMAIRE DES FIGURES SUMMARY DESCRIPTION OF THE FIGURES
D'autres avantages et caractéristiques ressortiront mieux de la description qui va suivre de plusieurs variantes d'exécution, données à titre d'exemples non limitatifs, du récepteur d'une centrale solaire à concentration linéaire conforme à l'invention, en référence aux dessins annexés sur lesquels :
- la figure 1 est une vue en perspective d'une centrale solaire à concentration linéaire conforme à l'invention, Other advantages and features will emerge more clearly from the following description of several variant embodiments, given by way of non-limiting examples, of the receiver of a linear concentration solar power plant according to the invention, with reference to the drawings. annexed in which: FIG. 1 is a perspective view of a linear concentration solar power plant according to the invention,
- la figure 2 est une vue en perspective d'un champ de collecte de la centrale solaire à concentration linéaire suivant l'invention, FIG. 2 is a perspective view of a collection field of the linear concentration solar power plant according to the invention,
- la figure 3 est une vue en coupe transversale du récepteur de la centrale solaire à concentration linéaire suivant l'invention, FIG. 3 is a cross-sectional view of the receiver of the linear concentration solar power plant according to the invention,
- la figure 4 est une vue en coupe transversale d'une variante d'exécution du récepteur de la centrale solaire à concentration linéaire suivant l'invention, FIG. 4 is a cross-sectional view of an alternative embodiment of the receiver of the linear concentration solar power plant according to the invention,
- la figure 5 est une vue en coupe transversale d'un détail de la variante d'exécution du récepteur de la centrale solaire à concentration linéaire suivant l'invention, FIG. 5 is a cross-sectional view of a detail of the alternative embodiment of the receiver of the linear concentration solar power plant according to the invention,
- la figure 6 est une vue en perspective de la verrière anti-réfléchissante de la variante d'exécution du récepteur de la centrale solaire à concentration linéaire suivant l'invention, FIG. 6 is a perspective view of the anti-reflective canopy of the alternative embodiment of the receiver of the linear concentration solar power plant according to the invention,
- la figure 7 est une vue de dessus de la verrière anti-réfléchissante de la variante d'exécution du récepteur de la centrale solaire à concentration linéaire suivant l'invention. FIG. 7 is a view from above of the anti-reflective canopy of the variant embodiment of the receiver of the linear concentration solar power plant according to the invention.
DESCRIPTION DÉTAILLÉE DE L'INVENTION DETAILED DESCRIPTION OF THE INVENTION
Dans la suite de la description du récepteur suivant l'invention, les mêmes références numériques désignent les mêmes éléments. Par ailleurs, les différentes vues ne sont pas nécessairement tracées à l'échelle. In the following description of the receiver according to the invention, the same reference numerals designate the same elements. In addition, the different views are not necessarily drawn to scale.
En référence aux figures 1 et 2, la centrale électrique solaire thermique à concentration linéaire est du type à miroir de Fresnel et comporte plusieurs champs de collecte solaire à concentration (1), un ensemble dit de production (2) comportant des moyens pour transformer l'énergie thermique en électricité par exemple. Chaque champ de collecte solaire à concentration (1) comprend une pluralité de réflecteurs primaires (3) solidaires d'un châssis (4) métallique qui concentrent les rayons solaires sur un tube absorbeur (5) dans lequel un fluide caloporteur circule, ledit fluide caloporteur consistant dans un fluide tel que de l'eau ou dans un gaz tel que de l'air par exemple. Ledit tube absorbeur (5) s'étend dans un récepteur (6) solidaire des extrémités supérieures de mats verticaux (7) portés par le châssis (4) comme il sera détaillé un peu plus loin. On entend par « réflecteur primaire » un dispositif permettant de suivre la course du Soleil pour
orienter toute la journée les rayons solaires vers le tube absorbeur (5) à l'aide de miroirs. Les miroirs plans (3) sont articulés au châssis (4) de manière à approximer une forme parabolique. Ainsi, chacun des miroirs peut pivoter en suivant la course du soleil pour rediriger et concentrer en permanence les rayons solaires vers le tube (5). With reference to FIGS. 1 and 2, the solar thermal power station with linear concentration is of the Fresnel mirror type and comprises several solar concentration collection fields (1), a so-called production unit (2) comprising means for transforming the thermal energy in electricity for example. Each solar concentrating collection field (1) comprises a plurality of primary reflectors (3) integral with a metal frame (4) which concentrate the solar rays on an absorber tube (5) in which a coolant circulates, said coolant consisting of a fluid such as water or a gas such as air for example. Said absorber tube (5) extends into a receiver (6) secured to the upper ends of vertical mats (7) carried by the frame (4) as will be detailed a little further. The term "primary reflector" means a device for tracking the course of the sun for direct sunlight all the day to the absorber tube (5) using mirrors. The plane mirrors (3) are articulated to the frame (4) so as to approximate a parabolic shape. Thus, each of the mirrors can rotate following the path of the sun to redirect and constantly focus the sunlight to the tube (5).
En référence à la figure 3, le récepteur (6) est constitué d'une pluralité de coques (8) sensiblement hémi-cylindriques obtenues dans du verre cellulaire, la paroi concave de chaque coque en verre cellulaire (8) recevant un miroir (9). Ledit miroir (9) consiste en un miroir de verre dont la face arrière est constituée d'une couche d'argent réfléchissante. Lesdites coques hémi-cylindriques (8) sont obtenues dans du verre cellulaire présentant de préférence une masse volumique comprise entre 1 10 et 165 kg/m3 et une conductivité thermique comprise entre 0,040 et 0,055 W/mK. La formation de chaque coque en verre cellulaire (8) est obtenue par moulage ou par découpe dans une matrice de verre cellulaire. Ledit miroir (9) est de préférence obtenu par cintrage gravitaire à chaud d'un miroir en verre dont la face arrière est constituée d'une couche d'argent réfléchissante protégée par du verre obtenu par frittage. Ledit miroir (9) peut, par exemple, consister dans un miroir tel que décrit dans le brevet américain US 8,585,225 déposé par la société Guardian Industries ou dans tout miroir équivalent. Par ailleurs, le récepteur (6) comporte des vitres anti-réfléchissantes (10) fermant les coques hémi-cylindriques (8). A cet effet, chaque coque hémi-cylindrique (8) comporte sur la paroi concave une gorge longitudinale (11) à proximité de l'extrémité libre de chaque branche de la coque (8), lesdites gorges (11) recevant les bords longitudinaux des vitres anti-réfléchissantes (10). With reference to FIG. 3, the receiver (6) consists of a plurality of substantially semicylindrical shells (8) obtained in cellular glass, the concave wall of each cellular glass shell (8) receiving a mirror (9). ). Said mirror (9) consists of a glass mirror whose rear face consists of a reflective silver layer. Said semi-cylindrical shells (8) are obtained in cellular glass preferably having a density of between 10 and 165 kg / m3 and a thermal conductivity of between 0.040 and 0.055 W / mK. The formation of each cellular glass shell (8) is obtained by molding or by cutting in a cellular glass matrix. Said mirror (9) is preferably obtained by gravitational hot bending of a glass mirror whose rear face consists of a reflective silver layer protected by sintered glass. Said mirror (9) may, for example, consist of a mirror as described in US Pat. No. 8,585,225 filed by Guardian Industries or in any equivalent mirror. In addition, the receiver (6) has anti-reflective panes (10) closing the hemi-cylindrical shells (8). To this end, each hemi-cylindrical shell (8) comprises on the concave wall a longitudinal groove (11) near the free end of each branch of the shell (8), said grooves (11) receiving the longitudinal edges of the anti-reflective glass (10).
Accessoirement, la paroi convexe des coques hémi-cylindriques (8) est revêtue d'une couche de protection. Cette couche de protection peut consister, par exemple, dans une feuille d'aluminium, similaire aux feuilles d'aluminium utilisées pour le calorifugeage de tubes, collée sur la paroi convexe desdites coques hémi-cylindriques (8) ou dans une couche d'un matériau auto-adhésif d'étanchéité appelé Terostat® et commercialisé par la société Foamglas.
On observera que l'utilisation de coques isolantes en verre cellulaire (8) permet de s'affranchir du caisson métallique permettant la tenue mécanique du récepteur. En effet, le verre cellulaire est très rigide, en comparaison des autres matériaux isolants généralement employés. Ceci permet de limiter le poids de l'ensemble, son coût, ainsi que l'ombre portée par le récepteur sur les réflecteurs primaires situés en contrebas. Contrairement aux laines minérales, le verre cellulaire présente également une forte étanchéité à l'eau et à la vapeur d'eau, qui peut se former lors de la montée en température de l'air en cas de forte humidité. Le choix de réflecteurs secondaires en verre permet d'atteindre de plus hautes températures sans effet néfaste associé à la corrosion de la face avant, ou à la déformation des miroirs, contrairement aux réflecteurs secondaires de l'art antérieur. Par ailleurs, le coefficient de dilatation étant presque identique entre le verre et le verre cellulaire, les effets de la dilatation relative sont très fortement limités. Enfin, les miroirs en verre possèdent des caractéristiques optiques (réflectivité et spécularité) bien supérieures à celles des tôles en aluminium poli. Incidentally, the convex wall of the hemi-cylindrical shells (8) is coated with a protective layer. This protective layer may consist, for example, in an aluminum foil, similar to the aluminum foils used for the heat insulation of tubes, bonded to the convex wall of said semi-cylindrical shells (8) or in a layer of a self-adhesive sealing material called Terostat® and marketed by Foamglas. It will be observed that the use of insulating shells made of cellular glass (8) makes it possible to dispense with the metal casing allowing the mechanical strength of the receiver. Indeed, the cellular glass is very rigid, in comparison with other insulating materials generally used. This makes it possible to limit the weight of the assembly, its cost, as well as the shadow carried by the receiver on the primary reflectors located below. Unlike mineral wool, cellular glass also has a high water and water vapor tightness, which can form when the air temperature rises in the event of high humidity. The choice of secondary glass reflectors makes it possible to reach higher temperatures without any adverse effect associated with the corrosion of the front face, or the deformation of the mirrors, unlike the secondary reflectors of the prior art. Moreover, the coefficient of expansion being almost identical between the glass and the cellular glass, the effects of the relative dilation are very strongly limited. Finally, glass mirrors have optical characteristics (reflectivity and specularity) much higher than those of polished aluminum sheets.
Le montage et la maintenance sur le système récepteur sont très largement facilités. En effet, les coques isolantes, incluant les réflecteurs secondaires et les vitres, sont simplement posées sur des cornières (12) qui sont solidarisées à l'extrémité supérieure des mats (7), ce qui facilite leur mise en place initiale et leur éventuel remplacement. Mounting and maintenance on the receiving system are greatly facilitated. Indeed, the insulating shells, including secondary reflectors and windows, are simply placed on brackets (12) which are secured to the upper end of the mats (7), which facilitates their initial placement and their possible replacement .
Selon une variante d'exécution du récepteur suivant l'invention, en référence aux figures 4 à 7, le récepteur (6) est constitué d'une pluralité de coques (8) sensiblement hémi-cylindriques obtenues dans du verre cellulaire, la paroi concave de chaque coque en verre cellulaire (8) recevant un miroir (9). Ledit miroir (9) consiste en un miroir de verre dont la face arrière est constituée d'une couche d'argent réfléchissante. Lesdites coques hémi-cylindriques (8) sont obtenues dans du verre cellulaire présentant de préférence une masse volumique comprise entre 110 et 165 kg/m3 et une conductivité thermique comprise entre 0,040 et 0,055 W/m . La formation de chaque coque en verre cellulaire (8) est obtenue par moulage ou par découpe dans une matrice de verre cellulaire. Ledit miroir (9) est de préférence obtenu par cintrage gravitaire à chaud d'un miroir en verre dont la face arrière est constituée d'une couche d'argent réfléchissante protégée par du
verre obtenu par frittage. Ledit miroir (9) peut, par exemple, consister dans un miroir tel que décrit dans le brevet américain US 8,585,225 déposé par la société Guardian Industries ou dans tout miroir équivalent. Ledit récepteur (6) comporte des raidisseurs (13) s'étendant de part et d'autre des coques hémi- cylindriques (8), lesdits raidisseurs (13) consistant dans des pièces en L dont les branches sont respectivement solidaires de la paroi externe des coques hémi-cylindriques (8) et du bord libre desdites coques (8). Il comporte également des seconds raidisseurs (14) en forme générale de U dont les branches sont repliées vers l'intérieur et sont solidaires du premier raidisseur (13), lesdits second raidisseurs (14) étant solidarisés à l'extrémité supérieure des mats (7) au moyen de boulons (15). According to an alternative embodiment of the receiver according to the invention, with reference to FIGS. 4 to 7, the receiver (6) consists of a plurality of substantially semicylindrical shells (8) obtained in cellular glass, the concave wall each cellular glass shell (8) receiving a mirror (9). Said mirror (9) consists of a glass mirror whose rear face consists of a reflective silver layer. Said hemi-cylindrical hulls (8) are obtained in cellular glass preferably having a density of between 110 and 165 kg / m 3 and a thermal conductivity of between 0.040 and 0.055 W / m 2. The formation of each cellular glass shell (8) is obtained by molding or by cutting in a cellular glass matrix. Said mirror (9) is preferably obtained by gravitational hot bending of a glass mirror whose rear face consists of a reflective silver layer protected by glass obtained by sintering. Said mirror (9) may, for example, consist of a mirror as described in US Pat. No. 8,585,225 filed by Guardian Industries or in any equivalent mirror. Said receiver (6) comprises stiffeners (13) extending on either side of the semi-cylindrical shells (8), said stiffeners (13) consisting of L-shaped parts whose branches are respectively integral with the outer wall semi-cylindrical shells (8) and the free edge of said shells (8). It also comprises second U-shaped stiffeners (14) whose branches are folded inwards and are integral with the first stiffener (13), said second stiffeners (14) being secured to the upper end of the mats (7). ) by means of bolts (15).
Par ailleurs, en référence à la figure 4, le tube absorbeur (5) s'étend dans le récepteur (6) en prenant appui sur un support (16) solidaire de l'extrémité supérieure du mat (7). Ledit support (16) consiste dans un rouleau (17) présentant un corps central cylindrique (18) muni d'une gorge annulaire (19) de telle manière que la surface de contact du tube absorbeur (5) sur la gorge annulaire (19) du rouleau (17) soit réduite à deux points et des axes (20) montés libre en rotation dans des lumières pratiquées dans les branches (21) d'un étrier (22) en forme générale de U. De manière particulièrement avantageuse, le coefficient de frottement entre les axes (20) du rouleau (17) et l'étrier (22) est inférieur ou égal au coefficient de frottement entre le rouleau (17) et le tube absorbeur (5). Par exemple, le rouleau (17) et ses axes (20) ainsi que l'étrier (22) sont réalisés en acier inoxydable et/ou silicate d'alumine. Furthermore, with reference to FIG. 4, the absorber tube (5) extends into the receiver (6) while resting on a support (16) integral with the upper end of the mat (7). Said support (16) consists of a roller (17) having a cylindrical central body (18) provided with an annular groove (19) so that the contact surface of the absorber tube (5) on the annular groove (19) the roller (17) is reduced to two points and the shafts (20) mounted free to rotate in slots in the legs (21) of a stirrup (22) generally U-shaped. Particularly advantageously, the coefficient friction between the axes (20) of the roller (17) and the stirrup (22) is less than or equal to the coefficient of friction between the roller (17) and the absorber tube (5). For example, the roller (17) and its axes (20) and the stirrup (22) are made of stainless steel and / or alumina silicate.
Dans cet exemple particulier de réalisation, la gorge annulaire (19) présente une section de forme sensiblement trapézoïdale comportant un fond plat (23) et deux parois inclinées (24) de part et d'autre dudit fond (23) ; Toutefois, il est bien évident que la gorge annulaire (19) pourra présenter une section sensiblement hémi-circulaire dont la concavité présente un rayon de courbure inférieur au rayon de courbure du tube absorbeur (5) sans pour autant sortir du cadre de l'invention. In this particular embodiment, the annular groove (19) has a section of substantially trapezoidal shape comprising a flat bottom (23) and two inclined walls (24) on either side of said bottom (23); However, it is obvious that the annular groove (19) may have a substantially semi-circular section whose concavity has a radius of curvature less than the radius of curvature of the absorber tube (5) without departing from the scope of the invention .
On notera que l'invention présente ainsi de nombreux avantages. Tout d'abord, la faible surface de contact entre le rouleau (17) et le tube absorbeur (5) limite les efforts de friction entre ledit tube (5) et le rouleau (17). Ce faible frottement diminue l'usure de la
fine couche sélective du tube (5) lors de sa dilatation. De plus, la rotation du rouleau permet la libre dilatation longitudinale du tube (5). En effet, le tube absorbeur (5) est irradié par le rayonnement concentré du soleil ; plus la température de sa couche sélective est chaude, plus celle-ci est sensible à l'abrasion. Un fluide caloporteur circule à l'intérieure du tube (5), ce qui engendre un gradient de température suivant son axe longitudinal. En fixant l'extrémité chaude du tube absorbeur (5), la dilatation est contrainte de s'effectuer vers l'extrémité froide. Le mouvement relatif de la partie chaude par rapport à son support sera alors plus faible, la couche sélective à la surface extérieure du tube sera ainsi préservée. It will be noted that the invention thus has many advantages. First, the small contact area between the roller (17) and the absorber tube (5) limits the frictional forces between said tube (5) and the roller (17). This low friction reduces the wear of the thin selective layer of the tube (5) during its expansion. In addition, the rotation of the roller allows the free longitudinal expansion of the tube (5). Indeed, the absorber tube (5) is irradiated by the concentrated radiation of the sun; the more the temperature of its selective layer is hot, the more it is sensitive to abrasion. A coolant circulates inside the tube (5), which generates a temperature gradient along its longitudinal axis. By fixing the hot end of the absorber tube (5), the expansion is forced to proceed towards the cold end. The relative movement of the hot part relative to its support will then be lower, the selective layer on the outer surface of the tube will thus be preserved.
De plus, en référence aux figures 4 à 7, le récepteur (6) comporte également des vitres anti-réfléchissantes (10) s'étendant entre deux mats (7) sous le tube absorbeur (5). Lesdites vitres anti-réfléchissantes (10) sont portées par un cadre métallique (25) sensiblement rectangulaire et dont les extrémités sont munies d'un épaulement (26) apte à être solidarisé à l'extrémité supérieure des mats (7). Le cadre métallique (25) est obtenu à partir de profilé métalliques en forme général de L, la base du L formant un épaulement sur lequel prend appui les vitres anti-réfléchissantes (10) dont les bords sont munis d'un joint de dilatation et d'étanchéité (27). Un même cadre métallique (25) supporte plusieurs vitres anti-réfléchissantes (10) jointées deux à deux par un joint de dilatation et d'étanchéité (27). In addition, with reference to FIGS. 4 to 7, the receiver (6) also comprises anti-reflective glasses (10) extending between two mats (7) under the absorber tube (5). Said anti-reflective glasses (10) are carried by a metal frame (25) substantially rectangular and whose ends are provided with a shoulder (26) adapted to be secured to the upper end of the mats (7). The metal frame (25) is obtained from generally L-shaped metal profile, the base of the L forming a shoulder on which the anti-reflective panes (10) resting, whose edges are provided with an expansion joint and sealing (27). The same metal frame (25) supports a plurality of anti-reflective panes (10) joined in pairs by an expansion and sealing joint (27).
Enfin, il est bien évident que les exemples que l'on vient de donner ne sont que des illustrations particulières et en aucun cas limitatifs quant au domaine d'application de l'invention.
Finally, it is obvious that the examples which have just been given are only particular illustrations and in no way limiting as to the field of application of the invention.
Claims
REVENDICATIONS
1 - Centrale solaire à concentration linéaire comprenant un ensemble de réflecteurs dits primaires (3), tels que des miroirs de Fresnel, solidaires d'un châssis (4) et orientés pour réfléchir et concentrer le rayonnement solaire vers un récepteur s 'étendant longitudinalement au sommet de mats verticaux (7) solidaires duditchâssis (4), ledit récepteur comportant au moins un tube absorbeur (5) dans lequel circule un fluide caloporteur, un réflecteur secondaire (6) s'étendant au-dessus du tube (5) absorbeur parallèlement à ce dernier de manière à concentrer vers le tube absorbeur (5) le rayonnement solaire issu de l'ensemble des réflecteurs primaires, caractérisé en ce que le réflecteur secondaire (6) est constitué d'une pluralité de coques (8) sensiblement hémicylindriques obtenues dans du verre cellulaire, la paroi concave de chaque coque (8) en verre cellulaire recevant un miroir (9). 1 - Solar power station with linear concentration comprising a set of so-called primary reflectors (3), such as Fresnel mirrors, integral with a frame (4) and oriented to reflect and focus the solar radiation to a receiver extending longitudinally to vertex of vertical mats (7) integral with the chassis (4), said receiver comprising at least one absorber tube (5) in which circulates a heat transfer fluid, a secondary reflector (6) extending above the absorber tube (5) in parallel to the latter so as to concentrate towards the absorber tube (5) the solar radiation from the set of primary reflectors, characterized in that the secondary reflector (6) consists of a plurality of substantially semicylindrical shells (8) obtained in cellular glass, the concave wall of each cellular glass shell (8) receiving a mirror (9).
2 - Centrale selon la revendication précédente caractérisée en ce que ledit miroir (9) consiste en un miroir de verre dont la face arrière est constituée d'une couche d'argent réfléchissante. 3 - Centrale selon l'une quelconque des revendications 1 ou 2 caractérisée en ce que le récepteur comporte des vitres anti-réfléchissantes (10) fermant les coques hémicylindriques (8). 2 - Plant according to the preceding claim characterized in that said mirror (9) consists of a glass mirror whose rear face is made of a reflective silver layer. 3 - Central according to any one of claims 1 or 2 characterized in that the receiver comprises anti-reflective panes (10) closing the hemicellular hulls (8).
4 - Centrale selon l'une quelconque des revendications 1 à 3 caractérisée en ce que chaque coque hémi-cylindrique (8) comporte sur la paroi concave une gorge longitudinale (11) à proximité de l'extrémité libre de chaque branche de la coque (8), lesdites gorges (11) recevant les vitres anti-réfléchissantes (10). 4 - Plant according to any one of claims 1 to 3 characterized in that each hemi-cylindrical shell (8) has on the concave wall a longitudinal groove (11) near the free end of each branch of the hull ( 8), said grooves (11) receiving the anti-reflective panes (10).
5 - Centrale selon l'une quelconque des revendications 1 à 4 caractérisée en ce que la paroi convexe des coques hémi-cylindriques (8) est revêtue d'une couche de protection.
6 - Centrale selon l'une quelconque des revendications 1 à 5 caractérisée en ce que les coques hémi-cylindriques (8) sont obtenues dans du verre cellulaire présentant une masse volumique comprise entre 110 et 165 kg/m3. 7 - Centrale selon l'une quelconque des revendications 1 à 6 caractérisée en ce que les coques (8) hémi-cylindriques sont obtenues dans du verre cellulaire présentant une conductivité thermique comprise entre 0,040 et 0,055 W/mK. 5 - Plant according to any one of claims 1 to 4 characterized in that the convex wall of the semi-cylindrical shells (8) is coated with a protective layer. 6 - Plant according to any one of claims 1 to 5 characterized in that the hemi-cylindrical shells (8) are obtained in cellular glass having a density of between 110 and 165 kg / m3. 7 - Plant according to any one of claims 1 to 6 characterized in that the hemi-cylindrical shells (8) are obtained in cellular glass having a thermal conductivity of between 0.040 and 0.055 W / mK.
8 - Procédé de fabrication d'un récepteur d'une centrale solaire à concentration linaire suivant l'une quelconque des revendications 1 à 7 caractérisé en ce qu'il comporte au moins les étapes suivantes de : 8 - Process for manufacturing a receiver of a linear concentration solar power plant according to any one of claims 1 to 7 characterized in that it comprises at least the following steps of:
- formation d'au moins une coque sensiblement hémi-cylindrique (8) dans une matrice de verre cellulaire, forming at least one substantially semi-cylindrical shell (8) in a cellular glass matrix,
- d'assemblage d'un miroir (9) sur la paroi concave de la coque hémi-cylindrique (8). - Assembling a mirror (9) on the concave wall of the hemi-cylindrical shell (8).
9 - Procédé suivant la revendication 8 caractérisé en ce que la formation de la coque (8) en verre cellulaire est obtenue par moulage. 10 - Procédé suivant la revendication 8 caractérisé en ce que la formation de la coque (8) en verre cellulaire est obtenue par découpe dans une matrice de verre cellulaire. 9 - Process according to claim 8 characterized in that the formation of the shell (8) of cellular glass is obtained by molding. 10 - Process according to claim 8 characterized in that the formation of the shell (8) of cellular glass is obtained by cutting in a cell glass matrix.
11 - Procédé suivant l'une quelconque des revendications 8 à 10 caractérisé en ce qu'il comporte une étape de cintrage gravitaire à chaud d'un miroir en verre dont la face arrière est constituée d'une couche d'argent réfléchissante protégée par du verre obtenu par frittage. 11 - Process according to any one of claims 8 to 10 characterized in that it comprises a heat gravity bending step of a glass mirror whose rear face consists of a reflective silver layer protected by glass obtained by sintering.
12 - Procédé suivant l'une quelconque des revendications 8 à 11 caractérisé en ce qu'il comporte une étape de formation de gorges longitudinales (11) sur la paroi concave de chaque coque (8), à proximité de l'extrémité libre de chaque branche de la coque (8), lesdites gorges (11) recevant des vitres anti-réfléchissantes. 12 - Process according to any one of claims 8 to 11 characterized in that it comprises a step of forming longitudinal grooves (11) on the concave wall of each shell (8), near the free end of each branch of the shell (8), said grooves (11) receiving anti-reflective glass.
13 - Procédé suivant l'une quelconque des revendications 8 à 12 caractérisée en ce que le verre cellulaire présente une masse volumique comprise entre 110 et 165 kg/m3.
14 - Procédé suivant l'une quelconque des revendications 8 à 13 caractérisée en ce que le verre cellulaire présente une conductivité thermique comprise entre 0,040 et 0,055 W/mK.
13 - Process according to any one of claims 8 to 12 characterized in that the cellular glass has a density of between 110 and 165 kg / m3. 14 - Process according to any one of claims 8 to 13 characterized in that the cell glass has a thermal conductivity of between 0.040 and 0.055 W / mK.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR1450826 | 2014-02-04 | ||
FR1450826A FR3017195B1 (en) | 2014-02-04 | 2014-02-04 | SECONDARY REFLECTOR FOR SOLAR POWER PLANT WITH LINEAR CONCENTRATION |
Publications (1)
Publication Number | Publication Date |
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WO2015118256A1 true WO2015118256A1 (en) | 2015-08-13 |
Family
ID=51063536
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/FR2015/050248 WO2015118256A1 (en) | 2014-02-04 | 2015-02-03 | Linear-concentration solar power plant having a secondary reflector |
Country Status (2)
Country | Link |
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FR (1) | FR3017195B1 (en) |
WO (1) | WO2015118256A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
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DE102022120177A1 (en) * | 2022-08-10 | 2024-02-15 | Frenell Ip Gmbh | SECONDARY REFLECTOR |
Citations (10)
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US4035065A (en) * | 1975-09-24 | 1977-07-12 | Nasa | Lightweight reflector assembly |
US4105429A (en) * | 1977-05-02 | 1978-08-08 | Delgado Manuel M | Method and apparatus for precision forming of plastic materials such as glass to precise dimensions from sheet material |
FR2396317A1 (en) * | 1977-06-28 | 1979-01-26 | Bfg Glassgroup | PROCESS FOR MANUFACTURING MIRRORS AND MIRRORS THUS OBTAINED |
DE10032882A1 (en) * | 2000-07-06 | 2002-01-17 | Bayer Ag | Plant for the use of solar energy |
BE1013565A3 (en) * | 2000-06-20 | 2002-04-02 | Suria Holdings Sarl | Device for using solar energy |
WO2009029277A2 (en) | 2007-08-27 | 2009-03-05 | Ausra, Inc. | Linear fresnel solar arrays |
DE102008010314A1 (en) * | 2008-02-21 | 2009-08-27 | Gerbracht, Heiner, Dipl.-Ing. | Container and solar power plant |
EP2447619A1 (en) * | 2010-10-26 | 2012-05-02 | Novatec Solar GmbH | Linear concentrating solar collector and method for reflector tracing in same |
WO2012156624A1 (en) | 2011-05-18 | 2012-11-22 | Constructions Industrielles De La Mediterranee - Cnim | Linear concentrating solar installation and secondary reflector that can be used in such an installation |
US8585225B2 (en) | 2006-03-23 | 2013-11-19 | Guardian Industries Corp. | Parabolic trough or dish reflector for use in concentrating solar power apparatus and method of making same |
-
2014
- 2014-02-04 FR FR1450826A patent/FR3017195B1/en not_active Expired - Fee Related
-
2015
- 2015-02-03 WO PCT/FR2015/050248 patent/WO2015118256A1/en active Application Filing
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4035065A (en) * | 1975-09-24 | 1977-07-12 | Nasa | Lightweight reflector assembly |
US4105429A (en) * | 1977-05-02 | 1978-08-08 | Delgado Manuel M | Method and apparatus for precision forming of plastic materials such as glass to precise dimensions from sheet material |
FR2396317A1 (en) * | 1977-06-28 | 1979-01-26 | Bfg Glassgroup | PROCESS FOR MANUFACTURING MIRRORS AND MIRRORS THUS OBTAINED |
BE1013565A3 (en) * | 2000-06-20 | 2002-04-02 | Suria Holdings Sarl | Device for using solar energy |
DE10032882A1 (en) * | 2000-07-06 | 2002-01-17 | Bayer Ag | Plant for the use of solar energy |
US8585225B2 (en) | 2006-03-23 | 2013-11-19 | Guardian Industries Corp. | Parabolic trough or dish reflector for use in concentrating solar power apparatus and method of making same |
WO2009029277A2 (en) | 2007-08-27 | 2009-03-05 | Ausra, Inc. | Linear fresnel solar arrays |
DE102008010314A1 (en) * | 2008-02-21 | 2009-08-27 | Gerbracht, Heiner, Dipl.-Ing. | Container and solar power plant |
EP2447619A1 (en) * | 2010-10-26 | 2012-05-02 | Novatec Solar GmbH | Linear concentrating solar collector and method for reflector tracing in same |
WO2012156624A1 (en) | 2011-05-18 | 2012-11-22 | Constructions Industrielles De La Mediterranee - Cnim | Linear concentrating solar installation and secondary reflector that can be used in such an installation |
Also Published As
Publication number | Publication date |
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FR3017195B1 (en) | 2016-02-05 |
FR3017195A1 (en) | 2015-08-07 |
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