Mathematical model of heat transfer in a solar collector and its experimental validation

A mathematical model is proposed for heat transfer in a system involving a solar collector and a heat exchanger. An analytical solution is obtained for the problem of heat conduction through the collector wall under the Cauchy boundary conditions with regard for internal heat sources due to the solar energy flux. A schematic of an experimental setup involving a Solahart solar collector is presented, in which solar radiation heats a heat-transfer medium flowing by gravity. The observed temperatures of the heat-transfer medium at the collector outlet agree satisfactorily with those calculated within the proposed model.