Investigation of the coefficient of heat transfer and daily cumulative production in a single-slope solar distiller at different water depths

Abstract

ABSTRACT This work investigates the effects of water depth on the internal heat transfer coefficients and productivity of a solar distiller with a single slope in the summer season. Three different days were considered with three water depths of 1, 2, and 3 cm in the climatic conditions of Iraq. The results illustrate that the total heat transfer coefficients inside the solar distiller increase as the basin water’s depth decreases. The highest total coefficient of heat transfer was , which was obtained at around 1:00 pm with the minimum depth of basin water (1 cm). Furthermore, at 1-cm water depth, the solar distiller became productive earlier than with the other two depths. The productivity rate ranged from 240% at 9 am to 60% at 11 am. In the afternoon, the production rate was reduced to 18.5% at the end of the day in comparison with the depth of 2 cm and 52% in comparison with the depth of 3 cm. The lowest estimated cost of production for 1 l of distilled water was $0.033, which was achieved at the lowest water depth (1 cm), while $0.041 and $0.05 were obtained with 2 and 3 cm, respectively. Thus, 1 cm was the best depth in this study.