NUMERICAL THERMAL STUDY OF HEAT TRANSFER ENHANCEMENT IN LAMINAR-TURBULENT TRANSITION FLOW THROUGH ABSORBER PIPE OF PARABOLIC SOLAR TROUGH COLLECTOR SYSTEM

Abstract

Currently electricity generation technologies by thermal energy conversions become strong demand. The objective of this paper is to present a novel thermal study of absorber/receiver circular pipe of parabolic trough solar collector system for laminar and turbulent (k-ɛ model) fluids flow as well as two-dimensional numerical simulation is performed using CFD ANSYS FLUENT software. Significant improvements in heat transfer and velocity were discovered; the pattern of temperature distribution over the pipe absorber was displayed, and velocity vectors, pressure contours, and temperature contours were studied. The impact of increasing the heat flux towards the pipe wall is discussed. Heat transfer coefficient and Nusselt number increases with increasing of Reynolds number while drag and skin friction coefficients decrease when Reynolds number increases. The thermal performance factor of PTC is estimated, and it is found 74% in laminar flow condition. The model is validated by comparing its results with analytical model results and the validation approves the accuracy of the CFD analysis. In the future, it will be useful for solar thermal parabolic trough concentrators to study different working fluids for heat transfer.