DIGITAL SIMULATION OF TRANSIENT SOLAR STILL PROCESSES

A digital simulation method of analysing complicated solar still processes is outlined and used to process a preliminary mathematical model describing the system. Some of the more common variables such as water depth, wind velocity, still insulation, double glass covers, cover slope and daily variability are investigated. A finite difference approach is used to simulate heat flow to and from the soil. The results of the simulation indicate that water depth has little effect on productivity; insulation will improve this at shallow water depths; higher wind velocities and ambient temperatures increase output by a small amount; double glass covers considerably reduce output and, from an economical point of view, both double glass covers and high cover slopes are not justifiable; and that the effect on still performance of some changes can be predicted by considering the effect on water temperature and water-glass temperature difference. © 1969.