HEAT LOSS ESTIMATION OF LINEAR FRESNEL RECEIVER UNDER NON-UNIFORM CONCENTRATED SOLAR FLUX
Linear Fresnel reflector (LFR) system linearly focuses the solar rays on an absorber tube placed at the focal point of the mirror field. LFR concentrator has simple design, lower installation cost and greater stability of the structure. The present study investigates the modes of heat losses occurring in the receiver system. In this study, the non-uniform flux distributions obtained from the optical results are incorporated to analyze the thermal behavior of the system. The work implements the investigation with non-uniform flux distribution around the absorber which is the more practical way of analysis compared to the constant flux conditions carried out by the peers. The LFR being a line focus system, the flux along the axial direction is assumed to be the same and hence the flux distribution along the circumference of the absorber is considered for the current investigation. Investigation on heat loss for diameter ratio for wide range of DNI, emissivities are carried out. It is found the by coating the absorber with selective material, total and the radiative heat loss from the parabolic receive system can be reduced to 14% and 54% respectively. The effect of wind on the heat loss from the system is studied. Convective heat transfer dominates the total loss during wind condition.