a flat-plate collector system Black metal absorber surface glasses 222 Insulation Enclosure A cutaway view of a flat-plate solar collector with two cover glasses. A heat-transfer fluid is circulated through the tubular passages integrally formed into the metal absorber surface(Not drawn to scale.) 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan UniversityA cutaway view of a flat-plate solar collector with two cover glasses. A heat-transfer fluid is circulated through the tubular passages integrally formed into the metal absorber surface. (Not drawn to scale.) A flat-plate collector system