Back to results
US 4,949,704 AGranted
Solar collector for the generation of high temperature
AssigneeForshung e.V. Fraunhofer-Gesellschaft zur Forderung der angewandten
InventorAntonio Pfluger
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeForshung e.V. Fraunhofer-Gesellschaft zur Forderung der angewandten
InventorAntonio Pfluger
Estimating the term…
A solar collector for the generation of high temperatures including a tubke housing defining a cavity, a glass plate for sealingly closing the cavity, a selective absorber and a trasparent thermal insulation structure located on the inside of the glass plate. An air gap separates the selective absorber from the glass plate. The solar collector is operated at a vacuum of less than 10000 pascal by means of a vacuum pump. The transparent thermal insulating member reduces the air convection and acts similarly to a mulitple pane for the reflected, diffuse thermal radiation. High efficiencies are thus achievable even at large temperature difference between the absorber and the area outside the solar collector. The thermal insulation effect of the air gap and at the same time of the microporous thermal insulation located in the bottom of the housing is varied by regulation of the degree of vacuum. A higher air pressure results in greater thermal losses of the absorber toward the thermal insulation member and the microporous insulation, whereby the temperature of the absorber is controllable.
Solar collector for the generation of high temperatures, said solar collector including a housing, said housing defining a cavity, a glass plate forming a sealing closure for said cavity, a selective absorber disposed in said cavity, said cavity being at least partially evacuated so that it is at lower than atmospheric pressure, a transparent thermal insulation member sealingly secured to the glass plate inside said cavity, said thermal insulation member having a radiation length of less than 5 cm., a gap separating said thermal insulating member and said selective absorber, at least one of the inside walls of said housing having a microporous thermal insulating material disposed thereon, the pores of said microporous material being smaller than the mean free length of travel of air molecules at normal operating pressures in said cavity, and a heat exchange fluid in said cavity.
Dependencies are inferred from the claim text.