Abstract: A flat glass is provided that includes a first side face, an opposite, second side face, and at least one edge face. The flat glass has a linear predetermined breaking location on the first or second side face. The flat glass also has two mutually separated points, where at least one of the two mutually separated points lies on the linear predetermined breaking location. The two mutually separated points are each configured as a point of attack for a force for breaking the flat glass. The two mutually separated points have breaking forces required to break the flat glass that differ from one another in magnitude and/or direction.

Abstract: A method for introducing a protective gas into an annular space of a receiver tube, in particular for solar collectors, is provided where the annular space is formed at least by one outer cladding tube and an inner absorber tube of the receiver tube and the outer cladding tube is connected to the absorber tube by a wall. The method includes producing an opening that penetrates the cladding tube or the wall, introducing protective gas through the opening into the annular space, and subsequently closing the opening.

Abstract: The radiation-selective absorber coating, in particular for an absorber tube of a parabolic trough collector, includes a reflective layer which is reflective in the infrared range, at least one barrier layer arranged below the reflective layer, at least one absorption layer arranged above the reflective layer, an antireflection layer arranged above the absorption layer and at least one adhesion-enhancing layer arranged between the barrier layer and the reflective layer. The adhesion-enhancing layer preferably is a molybdenum layer, but can also be provided by a copper, titanium, titanium oxide, or silicon layer. The adhesion-enhancing layer preferably has a thickness of 5 to 50 nm.

Abstract: The present disclosure describes a method for discharging a hydrogen storage system that is found in the annular space of a receiver tube, in particular for solar collectors, wherein the annular space is formed at least by an outer-lying tubular jacket and an inner-lying absorber tube of the receiver tube, and the outer-lying tubular jacket is joined by means of a wall to the absorber tube. The method is hereby characterized in that a first opening penetrating the tubular jacket or the wall is produced under a protective gas atmosphere, wherein protective gas enters through the first opening into the annular space, after which a process chamber with a connection for a vacuum pump is arranged in a gas-tight manner above the first opening, the receiver tube is evacuated through the first opening, and the first opening is subsequently sealed in a gas-tight manner.

Abstract: The present disclosure describes a method for discharging a hydrogen storage system, which is found in the annular space of a receiver tube, in particular for solar collectors, wherein the annular space is formed between an outer-lying tubular jacket and an inner-lying absorber tube of the receiver tube, and the outer-lying tubular jacket is connected via a wall to the absorber tube in a gas-tight manner. The method is hereby characterized in that an opening penetrating the tubular jacket or the wall is produced, free hydrogen in the annular space is pumped out through the opening, and the opening is subsequently sealed. The disclosure further describes a device for implementing the method.

Abstract: A retaining device for absorber tubes that have a metal tube and a glass cladding tube is provided. The retaining device includes a tube clamp made of two tube clamp halves, which have a main part with a retaining feature. The tube clamp surrounds the metal tube in the mounted state, and the retaining feature rests against the exterior of the metal tube. A thermal radiation shield is arranged on the interior of the main part of the tube clamp in order to reduce the loss of heat at the ends of the metal tube of the absorber tube.

Abstract: An absorber tube is provided that includes a metal tube, a glass sleeve tube surrounding the metal tube, and a glass-metal transition element is disposed on at least one end. The metal tube and the transition element can be moved relative to one another in the longitudinal direction and connected to one another by an expansion compensating device. An inner end of the expansion compensating device is fastened to an attachment element, which is connected to the transition element. An outer end of the expansion compensating device is fastened to the metal tube. An annular space section of the annular space is constructed between the transition and attachment elements. The attachment element has an annular disc on which the expansion compensating device is fastened. The absorber tube has at least one shielding device that has a first annular disc-shaped section disposed on at least one end in the annular space.

Abstract: An absorber pipe for solar collectors is provided. The absorber pipe includes a metal pipe for and a cladding pipe surrounding the metal pipe to form an annular space that can be evacuated. The absorber pipe can include a wall extending between the cladding pipe and the metal pipe for sealing the annular space and a retaining device for a getter material or a container filled with getter material or inert gas. The retaining device has a receiving section for receiving the getter material or the container. The retaining device is fastened to the wall. The absorber pipe can alternately include a getter material disposed in the annular space for binding free hydrogen present in the annular space and a reflector disposed in the annular space for reflecting radiation. The reflector has a housing with a support section for fastening and protecting the getter material from the radiation.

Abstract: An absorber tube is provided that has a central metal tube, a glass cladding tube, and a glass-metal transition element. The metal tube and the glass-metal transition element are connected to each other by an expansion compensation device such that they can be displaced relative to each other in the longitudinal direction. The expansion compensation device is arranged at least partially in an annular space between the metal tube and the glass-metal transition element. In the annular space, at least one shielding device is arranged, which has a first annular disc-shaped segment arranged at an axial distance in front of the end face and covers at least the connection region of the attachment element and the inner end of the expansion compensation device.

Abstract: An absorber tube, especially for solar collectors in solar thermal power plants with at least one collector mirror, is provided. The absorber tube includes a metal tube for supplying and heating a heat transfer medium, a sheath tube surrounding the metal tube to form an annular space that can be evacuated, a wall extending through the sheath tube and the metal tube to seal the annular space, and a getter material binding free hydrogen in the annular space. The absorber tube has a temperature variation device that changes the temperature of the getter material and the wall.

Abstract: A receiver system for a Fresnel solar plant is provided that includes an absorber tube defining a longitudinal direction, a mirror array that runs parallel to the longitudinal direction and is used for concentrating light beams onto the absorber tube, and a support frame for the absorber tube and the mirror array. A first suspension for holding the absorber tube and a second suspension for holding the mirror array or at least parts of the mirror array are independently mounted on the support frame. The first suspension has first compensation device while the second suspension has second compensation device. The first and second compensation devices allow for different expansions of the absorber tube and the mirror array or at least parts of the mirror array in the longitudinal direction.

Abstract: The present disclosure describes a method for discharging a hydrogen storage system, which is found in the annular space of a receiver tube, in particular for solar collectors, wherein the annular space is formed between an outer-lying tubular jacket and an inner-lying absorber tube of the receiver tube, and the outer-lying tubular jacket is connected via a wall to the absorber tube in a gas-tight manner. The method is hereby characterized in that an opening penetrating the tubular jacket or the wall is produced, free hydrogen in the annular space is pumped out through the opening, and the opening is subsequently sealed. The disclosure further describes a device for implementing the method.

Abstract: The present disclosure describes a method for discharging a hydrogen storage system that is found in the annular space of a receiver tube, in particular for solar collectors, wherein the annular space is formed at least by an outer-lying tubular jacket and an inner-lying absorber tube of the receiver tube, and the outer-lying tubular jacket is joined by means of a wall to the absorber tube. The method is hereby characterized in that a first opening penetrating the tubular jacket or the wall is produced under a protective gas atmosphere, wherein protective gas enters through the first opening into the annular space, after which a process chamber with a connection for a vacuum pump is arranged in a gas-tight manner above the first opening, the receiver tube is evacuated through the first opening, and the first opening is subsequently sealed in a gas-tight manner.

Abstract: A method for introducing a protective gas into an annular space of a receiver tube, in particular for solar collectors, is provided where the annular space is formed at least by one outer cladding tube and an inner absorber tube of the receiver tube and the outer cladding tube is connected to the absorber tube by a wall. The method includes producing an opening that penetrates the cladding tube or the wall, introducing protective gas through the opening into the annular space, and subsequently closing the opening.

Abstract: A receiver system for a Fresnel solar plant is provided. The system includes an absorber tube defining a longitudinal direction and a mirror array that runs parallel to the longitudinal direction. The mirror array has a mirror-symmetrical curve profile having at least one top apex for concentrating light beams onto the absorber tube. The mirror array has ventilation holes in the region of the apex.

Abstract: An absorber tube for solar collectors is provided. The absorber tube comprises a metal tube for carrying and heating a heat transfer medium, a sleeve tube enclosing the metal tube for forming an annular space that can be evacuated, a first container disposed in the annular space and filled with protective gas, an outer ring, and a transition element enclosing the metal tube for sealing off the annular space. The first container includes an outlet opening closed by a closure material, which releases the outlet opening under external actuation for introducing the protective gas into the annular space. The external actuation is applied by an opening unit that is activated for releasing the outlet openings. The first container is fixed in the annular space by a retaining device, which is on the outer ring and/or on the transition element.

Abstract: An absorber tube is provided that includes a metal tube, a glass sleeve tube surrounding the metal tube, and a glass-metal transition element is disposed on at least one end. The metal tube and the transition element can be moved relative to one another in the longitudinal direction and connected to one another by an expansion compensating device. An inner end of the expansion compensating device is fastened to an attachment element, which is connected to the transition element. An outer end of the expansion compensating device is fastened to the metal tube. An annular space section of the annular space is constructed between the transition and attachment elements. The attachment element has an annular disc on which the expansion compensating device is fastened. The absorber tube has at least one shielding device that has a first annular disc-shaped section disposed on at least one end in the annular space.

Abstract: A retaining device for absorber tubes that have a metal tube and a glass cladding tube is provided. The retaining device includes a tube clamp made of two tube clamp halves, which have a main part with a retaining feature. The tube clamp surrounds the metal tube in the mounted state, and the retaining feature rests against the exterior of the metal tube. A thermal radiation shield is arranged on the interior of the main part of the tube clamp in order to reduce the loss of heat at the ends of the metal tube of the absorber tube.

Abstract: An absorber tube is provided that has a central metal tube, a glass cladding tube, and a glass-metal transition element. The metal tube and the glass-metal transition element are connected to each other by an expansion compensation device such that they can be displaced relative to each other in the longitudinal direction. The expansion compensation device is arranged at least partially in an annular space between the metal tube and the glass-metal transition element. In the annular space, at least one shielding device is arranged, which has a first annular disc-shaped segment arranged at an axial distance in front of the end face and covers at least the connection region of the attachment element and the inner end of the expansion compensation device.

Abstract: A receiver system for a Fresnel solar plant is provided that includes an absorber tube defining a longitudinal direction, a mirror array that runs parallel to the longitudinal direction and is used for concentrating light beams onto the absorber tube, and a support frame for the absorber tube and the mirror array. A first suspension for holding the absorber tube and a second suspension for holding the mirror array or at least parts of the mirror array are independently mounted on the support frame. The first suspension has first compensation device while the second suspension has second compensation device. The first and second compensation devices allow for different expansions of the absorber tube and the mirror array or at least parts of the mirror array in the longitudinal direction.