Heat transfer model for thermal performance analysis of parabolic trough solar collectors using nanofluids

The parabolic trough solar collector is one of the most frequently used technologies in solar concentrating applications. Several studies on the thermal modelling of these collectors have been reported in the literature, most commonly using water and thermal oils. This paper presents a thermal model of parabolic trough solar collectors for heating applications using nanofluid as heat transfer fluid. The thermal model is based on a thermal resistance circuit to obtain the heat fluxes through the surfaces of the receiver. The advantages, limitations, and assumptions of the model are described in detail. The Engineering Equation Solver was used as software to simulate the model. Furthermore, heat transfer experiments were performed on a parabolic collector fabricated by a local enterprise. The experiments were performed over a range of process parameters using alumina-water nanofluid as heat transfer fluid. Model predictions were found to be in good agreement with the experimental results obtained in the present study.