Comparative Analysis of Absorber Tubes of Parabolic Trough Solar Collector Using Therminol VP-1 as Heat Transfer Fluid

Abstract

This paper presents computational analysis of four different types of helically grooved copper absorber tubes (semicircular, rectangular, trapezoidal and triangular) having length of 2 m, inner and outer diameter of 19 and 25 mm, respectively. The flow velocities are calculated by fixing the turbulent Reynolds number of 4000. A constant heat flux of 818.5 W/m2 is supplied at the lower surface of the absorber tube that is facing the reflector. The simulation is performed using the finite volume-based tool ANSYS FLUENT 18.0. The standard k-ɛ RNG turbulence model is used for simulation. Thermo-hydraulic performance for these tubes is calculated as 2.42, 2.08, 2.10 and 2.70 for semicircular, rectangular, trapezoidal and triangular grooved absorber tubes. The results show that the thermal performance of the absorber tube with triangular groove is superior to the other types of grooves. The pressure drop for the same tube is also the lowest.