Abstract: Volumetric solar receivers are disclosed. An illustrated volumetric solar receiver includes a heat absorbing cavity (1), a glass window, and a working fluid inlet pipe (2) and an outlet pipe (3) connecting with the heat absorbing cavity (1). The glass window comprises a double-layer hollow glass (41 and 42). The hollow portion of the glass window forms the inner cavity (43). This inner cavity (43) is provided with an outlet (44) connected to the heat absorbing cavity (1). The working fluid inlet pipe (2) is connected with this inner cavity (43) and further with the heat absorbing cavity (1) via the outlet (44) of this inner cavity. This arrangement keeps the temperature at the glass window low and prevents local overheating, and also avoids waste of heat carried away by the cooling fluid from the glass window.

Abstract: A high concentration central receiver system and method provides improved reflectors and a unique heat removal system. The central receiver has a plurality of interconnected reflectors coupled to a tower structure at a predetermined height above ground for reflecting solar radiation. A plurality of concentrators are disposed between the reflectors and the ground such that the concentrators receive reflective solar radiation from the reflectors. The central receiver system further includes a heat removal system for removing heat from the reflectors and an area immediately adjacent the concentrators. Each reflector includes a mirror, a facet, and an adhesive compound. The adhesive compound is disposed between the mirror and the facet such that the mirror is fixed to the facet under a compressive stress.

Abstract: A reaction chamber has a surface to be protected and a longitudinal axis transverse to this surface. For the protection of the surface, a method is used comprising introducing a primary flow of reactants into the chamber in a manner whirling around the longitudinal axis thereof, withdrawing reaction products at an opposite end of the reaction chamber in a flow along the longitudinal axis, and introducing into the chamber a secondary protecting flow directed from a periphery of the surface towards the longitudinal axis. The primary flow and the flow of reaction products approximate a free vortex flow and a pressure created by this vortex flow keeps the secondary flow adjacent the surface to be protected, substantially over its entire area.

Abstract: A solar power plant having a plurality of receiver panels mounted in a circular fashion about a solar receiver. Each receiver panel includes a plurality of tubes that terminate at each end at a header. To eliminate the presence of gaps between the tubes of adjacent receiver panels the headers are staggered or beveled. In the staggered configuration the headers of adjacent receiver panels are located in different elevations so that the headers of adjacent receiver panels may overlap each other, thus allowing the headers and tubes of adjacent receiver panels to be positioned closer together to eliminate gaps between the tubes of adjacent panels. In the beveled configuration the headers are angled such that the terminal ends of adjacent headers are parallel and positioned in a closely abutting relationship, resulting in the absence of gaps between adjacent headers and tubes.

Abstract: A solar thermal energy transmission system having a bellows that sealingly interconnects a first structure to a second structure is disclosed. The bellows includes a surface that is compatible with a molten salt and is configured to resiliently deform in response to contraction and expansion of at least one of the first and second structures, to thereby accommodate relative movement of the structure(s) to which it is coupled.

Abstract: This invention provides a thin wall header fabricated from a nickel-base superalloy, UNS N06626, for the solar absorption panels in a molten nitrate salt solar central receiver. The thin wall header is obtained by using multiple flow distribution nozzles to yield the smallest diameter header having uniform flow distribution for the panel tubes while providing enough space to butt weld the tubes to the nozzles with an automatic orbital weld head and avoid overlapment of the nozzle reinforcement regions. This small diameter combined with the high allowable tensile stress of UNS N06626 results in a thin wall header. The thin wall small diameter UNS N06626 header with its low thermal expansion coefficient and small temperature gradients and differentials during cloud cover induced molten salt temperature transients yields low thermal strains in the tube nozzle to header region. The nozzles may be formed by direct extrusion from the header wall or by insert-welding a machined nozzle into the header wall.

Abstract: A method and high concentration central receiver system provide improved reflectors and a unique heat removal system. The central receiver has a plurality of interconnected reflectors coupled to a tower structure at a predetermined height above ground for reflecting solar radiation. A plurality of concentrators are disposed between the reflectors and the ground such that the concentrators receive reflective solar radiation from the reflectors. The central receiver system further includes a heat removal system for removing heat from the reflectors and an area immediately adjacent the concentrators. Each reflector includes a mirror, a facet, and an adhesive compound. The adhesive compound is disposed between the mirror and the facet such that the mirror is fixed to the facet under compressive stresses.

Abstract: A solar powered pipe for use in igniting pipe tobacco. The solar pipe has a light concentrating lens to direct the sun's rays onto the tobacco in a pipe and a retractable arm to regulate the intensity of the heat over the tobacco from the light concentrating lens. Both the lens and the retractable arm are connected to a mounting plate by pivotal joints. When the solar pipe lighter is not in use, it may be folded to fit inside a pocket.

Abstract: An apparatus for heating a volatile medium is provided. The apparatus of the invention includes a base and a rotatable lens positioned above the base. The rotatable lens rotates independently of the base in the direction of a light source. The lens is positioned such that a focal point of a lens is focused on the volatile medium. The heat generated by focusing the light in this manner vaporizes the volatile medium and releases the medium into the surrounding atmosphere in a continuous manner.

Abstract: This invention consists in a nonimaging device for concentration or collimation of radiation on a receiver or from an emitter (14), depending on the case. The device is made up of the lens (50), which surrounds the receiver and consists of the aspheric surface (21), and the lens (15), whose upper refractive surface (16) may be aspheric, while the lower surface is aspheric (17) in its central portion (between points 18 and 19) and has a structure with discontinuous slope (20) in its external portion, in which the faces (22) fundamentally refract the rays while the faces (23) reflect them by total internal reflection. The design method provides that the device properties of concentration/collimation are noticeably superior to those of the existing inventions.

Abstract: A solar radiation concentrating system (1) comprises at least two reflectors (12, 16) successively arranged along an optical path (4) of the system (1) so that a first (12) of the two reflectors (12, 16) reflects the radiation towards a second (16) of the two reflectors (12, 16). The reflectors (12, 16) have such spectral characteristics as to be capable of highly reflecting the radiation in a reflection range of wavelengths and absorbing the radiation in an absorption range of wavelengths, wherein the absorption range of wavelengths of the first reflector (12) substantially includes the absorption range of wavelengths of the second reflector (16).

Abstract: A geodome tower reflector for a beam down optics solar power system has three equidistantly spaced tower assemblies. A geodome reflector assembly is movably mounted to the plurality of tower assemblies for vertical movement along the plurality of tower assemblies. The geodome reflector assembly has a facet support structure. The facet support has a plurality of rigid frames to which facets are mounted. Each facet has a downwardly facing mirror for reflecting light from a heliostat to a receiver of the beam down optics solar power system.

Abstract: This invention provides a thin wall header fabricated from a nickel-base superalloy, UNS N06626, for the solar absorption panels in a molten nitrate salt solar central receiver. The thin wall header is obtained by using multiple flow distribution nozzles to yield the smallest diameter header having uniform flow distribution for the panel tubes while providing enough space to butt weld the tubes to the nozzles with an automatic orbital weld head and avoid overlapment of the nozzle reinforcement regions. This small diameter combined with the high allowable tensile stress of UNS N06626 results in a thin wall header. The thin wall small diameter UNS N06626 header with its low thermal expansion coefficient and small temperature gradients and differentials during cloud cover induced molten salt temperature transients yields low thermal strains in the tube nozzle to header region. The nozzles may be formed by direct extrusion from the header wall or by insert-welding a machined nozzle into the header wall.

Abstract: A central solar receiver comprises an axisymmetric housing having front and rear ends and having an aperture at the front end, an elongated tubular window mounted in the aperture co-axially with the housing, a volumetric solar absorber disposed within the housing and extending around and along the elongated window for absorbing solar radiation that has passed therethrough; and working fluid ingress and egress formed in the housing so as to, respectively, inject thereto, and withdraw therefrom, a pressurized working fluid in a manner enabling the working fluid interaction with the volumetric absorber. The window has an open front end which is secured to the housing at the front end thereof, and a closed rear end which is disposed adjacent the rear end of the housing and is free of any securing thereto.

Abstract: A method and high concentration central receiver system provide improved reflectors and a unique heat removal system. The central receiver has a plurality of interconnected reflectors coupled to a tower structure at a predetermined height above ground for reflecting solar radiation. A plurality of concentrators are disposed between the reflectors and the ground such that the concentrators receive reflective solar radiation from the reflectors. The central receiver system further includes a heat removal system for removing heat from the reflectors and an area immediately adjacent the concentrators. Each reflector includes a mirror, a facet, and an adhesive compound. The adhesive compound is disposed between the mirror and the facet such that the mirror is fixed to the facet under compressive stresses.

Abstract: Provided is a heat collector comprising a linear tubular heat collector member defining an internal passage for conducting fluid; a base member provided with a front surface defining a trough-shaped recess partly surrounding the heat collector member; and a plate member fitted in the recess and provided with a reflective front surface. Preferably, the plate member is engaged by the base member at both side edges thereof, and placed under a compressive load so as to undergo a buckling deformation and substantially conform to a surface contour of the recess.

Abstract: Solar energy receiver having two or more regions for acceptance of solar radiation, and a means for splitting the solar radiation into two or more wavelength bands. A different band of radiation is incident upon each of the regions. At least one of the regions includes a means, such as a filter, to substantially prevent radiation having a wavelength longer than that incident on the region from leaving the region.

Abstract: A novel, high-efficiency, extremely light-weight, inflatable refractive solar concentrator for space power is described. It consists of a flexible Fresnel lens, flexible sides, and a back surface, together enclosing a volume of space which can be filled with low pressure gas to deploy the concentrator on orbit. The back surface supports the energy receiver/converter located in the focal region of the Fresnel lens. The back surface can also serve as the waste heat radiator. Prior to deployment, the deflated flexible lens and sides are folded against the back surface to form a flat, low-volume package for efficient launch into space. The inflatable concentrator can be configured to provide either a line focus or a point focus of sunlight. The new inflatable concentrator approach will provide significant advantages over the prior art in two different space power areas: photovoltaic concentrator arrays and high-temperature solar thermal conversion systems.

Abstract: An Integrated Solar Upper Stage receiver is shown for efficiently transferring heat from concentrated solar flux to an interior surface of an annular structure having a plurality of parallel passageways through which hydrogen gas flows and is heated to a high temperature to serve as a propellant in order to raise the ISUS from a low earth orbit to a geosynchronous orbit or the like. The receiver comprises a body of refractory material, such as graphite, in which each of the hydrogen flow passageways is lined with a thin tube of wrought rhenium metal. The exterior surfaces of the receiver are similarly clad with wrought rhenium, or coated with CVD rhenium, to prevent evaporation of graphite at high temperatures in outer space. Inlet and outlet manifolds which communicate with the rhenium-lined passageways are also constructed of wrought rhenium metal and serve to totally isolate the hydrogen from the graphite heat sink material so as to avoid chemical reaction therebetween.

Abstract: A concentrator for focusing solar radiation onto an elongate absorber, comprising a plurality of transverse supports arranged one behind the other in the longitudinal direction, stabilizing the concentrator in the transverse direction and defining the shape of the concentrator profile, and a thin-walled support structure resting on said transverse supports and having a plurality of adjacent longitudinally extending ribs stabilizing the concentrator in the longitudinal direction. In the transverse direction, the support structure adapts to the curved profile of the transverse supports and forms a light-weight and strong bearing for a reflector plate.

Abstract: A color-mixing lens for use in a concentrator system and methods of manufacture and operation thereof. The color-mixing lens includes: (1) a light-transmissive substrate that receives broad spectrum light from a source, (2) a first plurality of prisms, located on the substrate, that refract and chromatically disperse the light received therein toward a first plurality of locations on an active region of a target cell, and (3) a second plurality of prisms located on the substrate that refract and chromatically disperse the light received therein toward a second plurality of locations on the active region. Relative dimensions of the first and second pluralities of prisms are preselected to cause the chromatically-dispersed light to mix and thereby increase a power output of the target cell by reducing inter-junction currents therein.

Abstract: The energy collector has a housing with a cover which is transparent to vble and thermal radiation. One or more heat collectors are disposed in the interior of the housing. The heat collectors are carried by a pipe through which a heat-transport medium flows. Each of the collectors is assigned a reflector of concave design underneath the respective heat collector. The width of the reflector is significantly greater (e.g. a multiple) than the width of the heat collector. The incident visible and/or thermal radiation is either incident on the front side of the heat collector or it is reflected onto its rear side by the associated reflector. A large portion or all of the rear surface of the collector is covered with photovoltaic elements onto which focused light energy is aimed by the concave reflectors.

Abstract: A solar receiver (1) for a solar-thermal power plant, comprising a receiver surface (2) facing towards the concentrated incident solar radiation (8) and including a plurality of mutually spaced absorber bodies (3), is provided with gas channels arranged between the absorber bodies (3) for supplying a gas or gaseous mixture (11) adapted to absorb solar radiation (8) to a region located in front of the receiver surface (2). In this region, the gas (11) will absorb a part of the incident solar radiation (8) and then will be sucked together with the ambient air (9) through the absorber bodies (3) to be further heated therein.

Abstract: A sunlight collecting system comprises an oval mirror 1 directed downwardly and provided at a given elevation, and a plurality of heliostats 5 arranged on the ground about the oval mirror 1, each heliostat having a concave mirror 13 for reflecting and converging sunlight L onto the oval mirror 1. The sunlight L reflected on the concave mirror 13 of each heliostat 5 is focused to a point at a first focal point of the oval mirror 1, and converged to a second focal point of the oval mirror 1 after reflected by the oval mirror 1.

Abstract: A central solar receiver comprising a tubular housing with a central axis, a radiation admitting aperture and an absorber chamber having an outer wall, two oppositely located ends, an inner-wall-forming substantially tubular transparent window co-axial with the tubular housing. The solar receiver further comprises injection means near a first of the oppositely located ends and at least one egress opening means near a second of the oppositely located ends. The injection means are capable of injecting into the absorber chamber a multicomponent fluid mixture comprising at least one radiation absorbing component and are so designed that the fluid mixture is injected into the absorber chamber adjacent and essentially tangentially to the outer wall, whereby contact between the mixture and the window is reduced. The egress opening enables the egress of the fluid mixture from the absorber chamber.

Abstract: A shutter (1; 10) for regulating the fluid flow in an absorber pipe (D) of a solar-thermal power plant comprises a shutter body (2) with a central shutter opening (3) for the fluid (F) and a movable throttle element (4; 12) at least partly closing the shutter opening (3; 11). The throttle element (4) is connected to a motion element (6) that is in thermal contact with the fluid (F) and changes its shape as a function of the fluid temperature so that in case of an increased temperature of the fluid (F), the opening cross section of the shutter opening (3; 11) is enlarged, whereby the mass flow of the fluid (F) increases and the temperature thereof drops.

Abstract: An improved pressure vessel which has a fluid flowing through it can be simply manufactured and has a high operational safety. The fluid may be heated by radiation, such as solar radiation. A guiding device with inlet and outlet stream guides is arranged in the interior of the pressure vessel to guide a stream of the fluid. The inlet stream guide and the outlet stream guide are separate from one another, and are formed in the vessel interior by the guiding device. The stream of fluid is guided from the inlet stream guide to the outlet stream guide. Additionally, a branch stream of the stream of fluid is returned from the outlet stream guide to the inlet stream guide via a passage of the guiding device due to a lower pressure that is created in the inlet stream guide.

Abstract: A solar energy collector system which includes n groups (13, 14) of arrayed reflectors (15) and n 1 target receiver systems (10, 11, 12) which present absorbing surfaces to solar radiation that is reflected by the reflectors (15) within the groups. The receiver systems (10, 11, 12) are elevated relative to the reflectors (15) and the reflectors are pivotally mounted to support structure (19) in a manner such that they may be positioned angularly to reflect incident radiation toward one or the other of the receiver systems (10, 11, 12). The collector system is characterized in that at least some of the reflectors (15) within each group (13, 14) are arranged to be pivoted to an extent such that they may be oriented selectively to shift the direction of reflected incident soar radiation form one to another of the receiver systems.

Abstract: A transparent windows (4) for a solar radiation receiver assembly and a solar receiver assembly using the same, which assembly comprising a housing (2) having an aperture (3) and holding a volumetric solar absorber (5), the transparent window (4) mounted in the aperture (3) for the admission of incident concentrated solar radiation, shielding the volumetric solar absorber so as to form a sealed absorber chamber capable of holding a fluid medium, and means for the ingress and egress of the fluid medium. The transparent window (4) consists of a plurality of discrete transparent window segments (11,12) set in a common matrix (10) and is capable of withstanding high temperature.

Abstract: This invention provides a molten salt, solar central smooth tube receiver that is able to effectively absorb a peak solar flux of 1.42 MW/M.sup.2 by constructing the receiver from low cycle fatigue 625 alloy. Although higher flux levels are attainable for a smooth tube receiver by reducing the tube diameter to increase the salt's heat transfer coefficient, the receiver's size is optimized at this flux level to minimize capital and performance costs. Analogously, material provides substantial performance and capital cost improvements for receivers constructed with internally enhanced film coefficient tubes. The receiver's cost is minimized by utilizing autogenously welded and drawn tubing with the weld located at the tube's neutral axis to provide minimal strain at the weld.

Abstract: A portable, solar powered golf ball warming device includes a hollow black tube as a warming chamber for golf balls. The black tube has separate elastomer loading and dispensing apertures disposed at opposite ends thereof. The black tube is disposed within a transparent housing which also supports a parabolic reflector shield. The parabolic reflector shield reflects solar energy to thereby warm the black tube. During sunny weather conditions, the device provides continuous heat to modern golf balls including those of two piece construction. The golf balls serially move within the warming device such that ambient air does not breach the warming chamber.

Abstract: This invention reduces a molten salt, solar central receiver's size, pressure loss and cost by using a loose-tight-loose twist, twisted-tape insert inside the receiver's tubes to enhance the tube's heat transfer coefficient. This twist staging is designed to provide a higher heat transfer coefficient in the receiver's central region where the solar flux is high and a reduced pressure loss at the low solar flux entrance and exit end regions. Because the twisted-tape enhances the tube's heat transfer ability it can be made larger in diameter than a smooth bore tube at an equivalent pressure loss. This reduces the number of tubes which results in a substantial reduction in receiver cost.

Abstract: The invention relates to an absorber designed to absorb radiation and to transfer the energy of the radiation to a heat transport medium. To provide an absorber with high efficiency, the absorber according to the invention comprises a plurality of absorber components (32) attached to each other and having passages (42) formed therein for absorption of radiation and for suctional intake of a heat transport medium. Each absorber component (32) is provided with a dedicated mixing chamber (44) having said passages (42) of said absorber component (32) entering thereinto and comprising flow-restricting outlet orifices for connection to a suction means.

Abstract: A steam boiler (14) is situated on a tower (16) at the center of concentric tracks (17), (18), and (19). Poles (21) and (23) have wheels (25) running on the tracks. The poles are kept upright on the tracks with guylines (35) and struts (31) and (33). The poles carry frameworks (24) with mirrors (12) attached to them. As the earth turns, the poles move along the tracks, keeping the mirrors on the opposite side of the boiler from the sun and keeping sunlight focused approximately on the boiler. As the poles move, the frameworks pivot to fine tune the focusing. Each framework pivots about a horizontal axle (26) of the framework and about the vertical axis of one of the poles (21). Hydraulic cylinders (66) and (70) in series circuits (82) and (78) respectively pivot the frameworks collectively. The frameworks are arranged so the power needed to pivot the frameworks is the same on windy days and calm days.

Abstract: A diffuser to be used with a solar energy concentrator and a solar energy receiver to more uniformly distribute solar energy to the receiver and to reduce the amount of energy lost due to circulation of air into and out of the receiver. A portion of the solar energy passing through the energy diffusing cavities within the diffuser is reflected by the cavity walls and reoriented and diffused before being emitted to the receiver. The geometry of the energy diffusing cavities and the reflective characteristics of the cavity walls can be engineered to provide the desired degree of diffusional effect. The diffuser reduces the likelihood of inadvertent hot spots being formed, which allows the designed maximum receiver energy flux to be closer to the receiver tube material limits and allows for smaller, more compact, more efficient receivers. The diffuser also limits the circulation of air in the vicinity of the receiver tubes, which reduces energy losses and increases the overall efficiency of the system.

Abstract: A high-temperature receiver for converting concentrated solar radiation has a channel with an inlet and an outlet. An areal air-permeable support element is connected to the inlet. An absorber structure for absorbing solar radiation is supported by the support element and is made of an air-permeable mat material. Air is transported as a cooling medium through the absorber structure in a flow direction identical to a direction in which the solar radiation hits the absorber structure. The mat material has a first density in an area where the solar radiation enters the absorber structure and a second density in an area where the absorber structure faces the support element. The first density is lower than the second density. The first density favors absorption of the solar radiation and the second density provides for a secure fastening of the absorber structure on the support element.

Abstract: The invention comprises a solar assembly for heating a stove with solar energy. The assembly includes a foundation pipe having an opening. A substantially vertical pipe is positioned in the opening and the vertical pipe is capable of rotation relative to the foundation pipe. A stove is releasably attached to the vertical pole. A downward sloping arm is fixed to the top end of the vertical pole. A vertical adjustment member is slidably positionable on the downward sloping arm. The vertical adjustment member is capable of adjustment in height. A frame supporting a solar lens is pivotally attached to the vertical adjustment member. The vertical adjustment member is used to adjust the frame, and the solar lens, so that the solar lens directs solar energy to the stove. It is also contemplated that a solar panel or solar collector be positioned in place of the solar lens.

Abstract: A power generating system comprises a solar concentrator defining an effectively concave reflective surface on a surface of the earth for concentrating incoming solar energy. A solar collector is disposed in an underground chamber provided with an access opening. The solar collector receives solar energy concentrated by the concentrator and converting the concentrated solar energy to another energy form, generally thermal energy, which is subsequently convertible to electrical power. Directional componentry is provided for directing concentrated solar energy from the concentrator along a predefined folded transmission path through the access opening to the collector.

Abstract: A solar device has an air receiver with a housing and an absorber connected within the housing. The absorber is heated by solar radiation. The absorber has an upstream side and a downstream side, wherein a stream of air is guided through the absorber from the upstream side to the downstream side and heated to generate heated air and wherein said heated air is cooled to produce useable heat energy and cooled air. A device for returning at least a portion of the cooled air as return air in a plurality of partial streams to the absorber is provided for guiding the partial streams through the absorber counter to the stream of air without mixing therewith from the downstream side to the upstream side. A device for deflecting the partial stream at the upstream side is provided for deflecting the partial streams toward the upstream side.

Abstract: A solar rocket for propelling and powering the electronics of a spacecraft includes a black body cavity of thermal storage material. Propulsion tubes and a connected nozzle axially extend through the black body cavity for burning propellant in order to provide thrust for the rocket. An insulation sleeve is removably located at the outer periphery of the cavity of thermal storage material. Energy conversion diodes surround the insulation sleeve. The thermal storage material, the insulation sleeve and the energy conversion diodes form a receiver. The receiver has a pair of spaced apart holes therethrough which lead into an interior space of the black body cavity in order to receive sunlight. A mirror assembly is located near each hole of the receiver for harnessing sunlight and providing radiant energy through the holes into the internal space of the black body cavity.

Abstract: A radiant gas heating apparatus of the present invention includes a cylindrical member of a porous ceramic material adapted to be heated by radiation, and a flow passageway which directs gas radially through the pores of the ceramic material from one cylindrical surface of the cylindrical member to the other cylindrical surface thereof. A steam electrolyzing apparatus of the present invention includes a light focusing section having a porous ceramic member disposed within a transparent light-receiving section vessel, an electrolyzing cell having an oxygen electrode and a hydrogen electrode disposed on inner and outer surfaces of a cylindrical electrolyte, and a heat-insulating vessel covering the electrolyzing cell. In the steam electrolyzing apparatus, after low-temperature gas has passed through the space between the porous ceramic member and the light-receiving section vessel, the gas passes through the porous ceramic thereby being heated.

Abstract: The invention is drawn to a planar luminescent solar concentrator including an optical fiber comprised of laser material. Solar energy collected by the concentrator is processed into laser radiation emitted by the optical fiber with high energy density corresponding to a concentration factor much greater than possible with prior art luminescent solar concentrators.

Abstract: A central solar receiver comprising a housing with a frusto-conical window for the admission of incident concentrated solar radiation, a volumetric solar absorber within the housing surrounding the window, means for the injection of working fluid into contact with the volumetric solar absorber and means for the withdrawal of heated working fluid. The frusto-conical window makes the receiver suitable for operation at elevated pressure.

Abstract: A central solar receiver comprising a housing with a window for the admission of incident concentrated solar radiation, a volumetric solar absorber within the housing comprising a base body holding an array of absorber members spaced from each other and projecting from one face thereof with their free ends facing said window, means for the injection of working fluid into the volumetric solar absorber in flow directions which intersect the absorber members and means for the withdrawal of heated working fluid. The window of the central solar receiver is a tubular frusto-conical body coaxial with the housing, whereby the receiver is adapted for operation at elevated pressure.

Abstract: A solar collector including a plate disposed in a bottom portion of a housing, one or more tubes disposed above the plate for accommodating water, and one or more reflecting surfaces formed in the upper portion of the plate for reflecting lights in order to heat the water contained in the tubes.

Abstract: A central solar receiver with a volumetric solar absorber. The volumetric absorber comprises an array of absorber members mounted on a base body and facing a window that admits concentrated solar radiation. Working fluid is injected into the volumetric absorber so as to flow in directions which intersect the absorber members.