Experimental investigation of a novel design of cavity receiver for a parabolic dish collector humidification-dehumidification desalination system

Abstract

In this study, a desalination cycle using a humidification-dehumidification method equipped with a parabolic dish collector has been experimentally designed and tested under the climatic conditions of Semnan City. A novel geometry of cylindrical-conical for parabolic dish collector’s cavity receiver was selected and used in this desalination system. For the experimental tests, four water samples were selected from the non-conventional brackish water sources in Semnan province. The performance of the desalination cycle was investigated for four days in the maximum period from 9:00 a.m. to 3:00 p.m. According to the results obtained from the tests, the maximum thermal efficiency of the collector with the cylindrical-conical cavity receiver for the test with water sample with electrical conductivity of 21,500 µS/cm was obtained as 45.49%. The highest water production rate was 0.966 l/day for a water sample with an electrical conductivity of 13,810 µS/cm. The average hourly water production rate for the saltiest water has reached the highest value, equivalent to 147.67 cm3/h. It was also found that there is an increasing trend of water production with an increase in the salinity of brackish water. The maximum hourly exergy efficiency of the system was 14.04% for a water sample with an electrical conductivity of 21,500 µS/cm. An increase in hourly exergy efficiency was observed with the increase in water salinity.