Performance analysis of double slope wick-type solar still with varying thermal insulation beneath the wick surface

ABSTRACT

A double slope wick-type solar still has been designed and fabricated with varying thickness of insulation beneath the tilted wick portion and optimum thickness for effective distillation has been presented. Energy balance equations have been written for each element of the still including the climatic parameters such as solar radiation intensity and ambient temperature, and design parameters of the proposed system. Theoretical equations have been developed for heat and mass transfer mechanisms inside the still. The efficiency of the still is found to be 46% for the insulation thickness of 0.06 m beneath the tilted wick portion and sides of the still. It is confirmed that the bottom and sides of the wick-type solar still should be thermally insulated with a minimum thickness of 0.06 m for better production and performance. Moreover, the distilled water obtained has much lesser value of electrical conductivity and minerals as compared to the raw water.

Keywords:

• Wick-type solar still
• Energy balance equation
• Heat transfer coefficients
• Efficiency