Design development and performance evaluation of concentrating solar thermal desalination device for hot arid region of India

Abstract

A parabolic concentrating solar thermal desalination device was designed, developed, and fabricated. The surface area of the parabolic concentrator made of steel is 2.60 m and the projected area of the disc is 1.50 m. The performance evaluation of the device during the summer and winter months of the year 2019 in the hot arid climate of Jodhpur, India was carried out by measuring distillate output per day. The maximum productivity of 6.5 L/d within 9 h in a day was measured with the maximum average solar insolation of 745 W m–2 during May 2019 and 5.5 L/d in winter month December 2019. The maximum daily average efficiency of 34.2% in May and 32.3% in December was calculated with a maximum hourly output of 0.85 L/h. The distillate output of solar desalination device is to be mixed with the available saline water in appropriate proportion to make it drinkable. In fact, as much as 20 L/d of a potable water (150–180 ppm TDS – total dissolved solids) can be made available in a day from raw water containing 300 ppm TDS by a solar desalination device. The economic evaluation of the parabolic concentrating solar thermal desalination device revealed that high value of internal rate of return (74.6%) and low value of the payback period (1.45 y) make the unit very cost-efficient. The economic attributes of the system revealed its economic viability. Therefore, this solar desalination device can be successfully used for desalination of saline water in rural arid areas for meeting requirement of potable water as per WHO guidelines for drinking water quality.