| 摘要 |
<p>This invention provides an improved solar collector of the type employing two concentrically disposed glass tubes having their axial end portions sealingly united to form a double-walled structure, with the annular space between the inner and outer glass tubes being highly evacuated. A heat transfer fluid flows thru the inner tube. The outer surface of the innermost tube is provided with a coating of a solar energy absorbent material to trap energy incident upon the outer tube within the inner tube and the heat transfer fluid. At least one axial section of the inner glass tube is radially inwardly deformed to define a unique bellows configuration to permit absorption of differential thermal expansion of the inner and outer tubes. Improved means for connecting such double-walled tubes in end to end relationship to define a conduit for the heat transfer fluid are also disclosed.</p> |
