Heat losses of absorption solar collectors with capacious semicylindrical receivers and heat-insulated flat-plate bases

The absence of transparent insulation above the light-absorbing surface of absorption solar collectors with capacious semicylindrical radiation receivers and heat-insulated flat-plate base is the key reason for high heat losses. It is interesting to determine the specific heat losses of these collectors per unit area of their lateral light-absorbing surface as a function of the temperature difference between the water heated there and the environment. This paper discusses the derivation of calculation expressions for specific heat losses and the reduced heat loss coefficient of absorption solar collectors with capacious semicylindrical receivers and heat-insulated flat-plate bases.