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 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 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 method of delivering guided radiation arriving via a first transparent medium having a first refractive index into a second transparent medium having a second refractive index that is smaller than the first refractive index, comprising: providing a transparent radiation delivery waveguide capable of admitting concentrated radiation and having a longitudinal axis and a third refractive index substantially equal to or greater than the first refractive index and adapted to guide the radiation along the longitudinal axis. The waveguide having a tapered radiation delivery portion of non-circular cross-sectional shape. Mounting the waveguide in optical contact with the first transparent medium so that the radiation delivery portion projects inside the second transparent medium.

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 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.