Mathematical study of a double-slope passive solar distiller with water heater condenser

In this article, the inevitable condensation losses from the back-side glass cover of a passive single-basin double-slope distiller (PSDD) were recovered in heating water inside a glass solar water heater (SWH) to produce hot water as an auxiliary product of the distiller. The transient thermal performance of the PSDD-SWH was mathematically modeled and compared to a conventional PSDD in actual weather circumstances. Compared to a conventional PSDD, the results revealed that the thermal efficiency of the PSDD-SWH increased by 18 % to 83 % during the day. In addition, increasing the water mass inside the water heater from 3 kg to 18 kg increased the thermal efficiency of the PSDD-SWH by about 50 % despite decreasing the total distillate by less than 1 %. Moreover, the thermal performance of the PSDD-SWH, in terms of distillate production, hot water temperature, and thermal efficiency boomed in hot climates with high solar irradiation and high ambient temperatures. Furthermore, insulating the glass covers of the PSDD-SWH during off-sun hours significantly enhanced the thermal performance of the PSDD-SWH.