Effect of overall Heat loss coefficient on performance of Circular Solar collector for close water open air (CWOA) humidification dehumidification process

Abstract

Solar energy is an abandoned energy source which are alternate in comparison of other resources. One of the
simplest and most direct applications of this energy is the conversion of solar radiation into heat. The flat-plate collector
is commonly used which having high heat loss result in low convective heat transfer. Also it can be used in water heating
systems serious corrosion problem arrived. The solar air heater is newly developed air tight circular collector whose
abso rbe r is usually made of a metal tube o f high thermal conductivity, such as copper or aluminum. Its surface is coated
with dull black painted over the entire outer surfaces to maximi ze radiant energy absorption while minimizing radiant
energy emission. Qa i s the amount of solar radiation received by the circular collector. As the collector absorbs heat
ene rgy ,e ffec t in its temperature rising , comparison with than that of the surrounding and heat is lost in to the
atmosphere by convection and re radiation, this heat loss rate can be presented by Ql.The overall heat loss coefficient is a
key factor for the performance of air tight circular solar collector. The overall heat loss coefficient of airtight circular
collector is increase with increasing in absorber temperature, which wills effects on efficiency of airtight circular solar
collector.