Numerical Simulation of Elliptical Absorber Tube in Parabolic Trough Collector for Better Heat Transfer

Development on technology for harnessing solar energy has increased recently which makes a platform for generating thermal energy or electrical energy. Solar energy makes a pavement for use in many industries, residential and commercial sectors. The absorber tube of Parabolic Trough Collector (PTC) performance improvement is one of the major research topics in the field of solar energy engineering. Many earlier studies on absorber tube have showed much enhancement in heat transfer. In this study the traditional absorber tube has been experimentally tested and compared with a newly fabricated absorber tube with elliptical cross section for handling better heat transfer. Generally the mass flow rate is the main parameter which aids the PTC in absorbing more solar flux. In the present study the cylindrical absorber tube with circular cross section has been modified with an elliptical cross section. The designed elliptical absorber tube is fabricated and its performances have been calculated experimentally and numerically using MSC NASTRAN. The heat transfer and pressure drop are calculated for both type of absorber by varying three different mass flow rate such as 0.014, 0.021, 0.028 kg/s. The numerical 3-dimensional analysis shows a uniform heat transfer, which reduces thermal fatigue in elliptical absorber and consecutively found high pressure drop compared to circular absorber tube. Result also shows a slight improvement in outlet temperature on elliptical absorber which ultimately impacts the collector efficiency.