Vacuum flat plate solar absorber for e.g. heating of dwelling, has vacuum enclosure with internal tube whose external surface has selective layer, and interstice closed by sealing device provided between tube and heat transfer unit

摘要

The absorber has a vacuum enclosure with external and internal tubes (34, 36). A heat transfer unit (50), with water under the liquid and vapor phases, has a part disposed in the tube (36) and another part extending out of the tube (36) whose external surface has a selective layer (58). An interstice (52) provided between the tube (36) and the unit (50) contains an interface fluid and is closed by a sealing device (54).