Solar collector, has protective screen rotatable around vacuum tube between two positions, where screen shields tube against solar radiation in one position, and screen exposes tube to solar radiation in another position

摘要

The collector has an absorber pipe (11) contained in a vacuum tube (10). A protective screen (12) is provided, where the protective screen is rotatable around the vacuum tube between a position (P1) and another position, where the protective screen shields the vacuum tube against solar radiation in one of the positions and the screen exposes the vacuum tube to the solar radiation in the other position.