Solar collector panel - contg. self-circulating two-component heat carrier liq., giving reduced heat loss at the cover plate

摘要

In a solar collector which is covered by a radiation transparent pane (2) and is mounted in a heat insulating support (1), (i) the collector employs a two-component heat carrier liq. at least one component of which evaporates at the operating temp.; (ii) the liq. trickles through heat insulating elements (7), e.g. square or hexagonal honeycombs, and takes up heat by constant evapn. of the component(s); (iii) the evaporated component(s) and the residual liq. pass along a light absorbing surface (8) to the lower end of the sloping collector, at which point useful heat can be extracted; (iv) the liq. then passes through pipes or vessels (9) behind the light absorbing surface (8) for residual heat transfer to liq. flowing in front of this surface (8), the expansion of the evaporated compound(s) being used to advance the vapour and the liq. and the pipes or heat exchange vessels (9) being so thin that adhesion forces prevent liq. backflow; (v) the liq. then passes into a gap (3) between the cover plane (2) and a light transparent pane (4), opt. sepd. by an air gap from a further underlying light transparent pane (5), liq. permeable connections (6) of capillary structure being formed through the light transparent pane(s) (4,5) for trickle passage of the liq. onto the collector inside where the liq. can evaporate again. ADVANTAGE - The flat solar collector employs a two-component heat carrier liq. which circulates automatically and provides additional heat take-up by evapn. and condensation. The design reduces heat loss at the cover plate.