INSTANTANEOUS THERMAL EFFICIENCY OF AN ACTIVE SOLAR-STILL

A thermal analysis of a solar distillation unit integrated with a coll ector panel through a tube-in-tube heat exchanger has been presented. An expression for the thermal efficiency has been derived in terms of dimensionless parameters; namely, number of(heat) transfer units (NTU) and the effectiveness of the heat exchanger and the collector and the still parameters. It is observed that the instantaneous thermal effic iency of the system decreases with an increase of collector area, due to the higher operating temperature range of the distillation system.