Experimental Study to Enhance the Productivity of the Active Solar Still Using U-Copper Tube in Evacuated Tubes with Reflectors

Abstract

In the present work, experimental study is done to explain the effect of coupling U-copper tube in evacuated tubes solar collector with reflectors, medium in evacuated tubes and weather conditions on the system productivity. Single slope-linear basin solar still have been used to do this purpose. Brackish water is pumped through evacuated tubes to absorb energy and return to the still, also three medium type in evacuated tubes have been used. The tests are done from May to August/2017 in Mosul City-Iraq (Latitude: 35.866°N Longitude: 43.296°E Elevation: 200 m, and  South-East face). Results showed that the maximum and minimum productivity of the simple and active solar still were ( 2.505, 8.437) and (2.105, 6.225) kg/m².day respectively. Increase the pump flow rate  from (1 to 3) liter/min. enhance the yield output by about 30%, the using of air, water and oil mediums in glass evacuated tube produce 6.690, 7.762 and 7.832 kg/m².day respectively. The maximum efficiency of the simple and active still are 30.2% and 60.3%. The maximum rate of increase in the water production were 144.5%, 166.3% and 178.33% in case of using air, water and oil in evacuated tubes at 2cm water level and pump flow rate  3 liter/min. The increase of water level in the solar still from 3 to 4cm decrease the productivity by 39%. also it has been conclude that the increase of pump flow rate  increase the collector efficiency.