Covering material for solar thermal power generating system and solar thermal power generating system formed by spreading the covering material

Abstract

A covering material for solar thermal power generation system, characterized in that it is made of a film which has a tensile yield strength of at least 10 N/mm 2 according to JIS K7127, a solar radiation transmittance of at least 85% according to JIS R3106, and a retention of at least 80% against the initial value of the tensile breakage strength after 5000 hours of the sunshine carbon arc lamp weather test according to JIS B7753.

1 . A covering material for solar thermal power generation system, characterized in that it is made of a film which has a tensile yield strength of at least 10 N/mm 2  according to JIS K7127, a solar radiation transmittance of at least 85% according to JIS R3106, and a retention of at least 80% against the initial value of the tensile breakage strength after 5000 hours of the sunshine carbon arc lamp weather test according to JIS B7753, wherein the film is a wide-width film formed by fusion-bonding ends of a plurality of films. 
     
     
         2 . The covering material for solar thermal power generation system according to  claim 1 , wherein the film is made of at least one member selected from the group consisting of an ethylene/tetrafluoroethylene copolymer, a tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, a tetrafluoroethylene/hexafluoropropylene copolymer, a tetrafluoroethylene/hexafluoropropylene/vinylidene fluoride copolymer, a polyvinylidene fluoride and a polyvinyl fluoride. 
     
     
         3 . The covering material for solar thermal power generation system according to  claim 1 , wherein the film is a film having a hydrophilic treated surface on one side. 
     
     
         4 . The covering material for solar thermal power generation system according to  claim 1 , wherein the film is a film having a cable attached to its end. 
     
     
         5 . The covering material for solar thermal power generation system according to  claim 4 , wherein the film having a cable attached to its end, is a film obtained by folding back the peripheral portion of the film to enclose the cable and thermally fusion-bonding the surfaces at the folded-back peripheral portion. 
     
     
         6 . The covering material for solar thermal power generation system according to  claim 5 , wherein the surfaces to be thermally fusion-bonded are non-hydrophilic treated surfaces. 
     
     
         7 . A solar thermal power generation system formed by spreading the covering material for solar thermal power generation system as defined in  claim 1  is stretched.