摘要 |
The invention relates to a trough collector having a focal area and an absorber tube arranged in the focal area, said absorber tube having an insulating area that extends from its outer surface to the inside, enclosing preferably a transport channel that runs through the absorber tube along its length and carries a heat-transporting medium, and is penetrated by at least one thermal opening that extends radially from the outside through the insulating area to the transport channel. According to the invention, the at least one thermal opening comprises a constriction for radiation passing through it, the focal area being located in the constriction. |