Analysis of temperature distribution over pipe surfaces of air-based cavity linear receiver for cross-linear concentration solar power system

This analysis is based on the computational fluid dynamics (CFD) of the air-based solar cavity linear receiver (CLR) of the cross-linear concentrated solar power plant. In this study, the temperature distribution along the pipe surface is investigated using a small section of a receiver. To study the variation of temperature over the surface of receiver pipes, a CFD model has been developed in Ansys Fluent. The analysis shows the effect of reflected radiation on the temperature variation over the front and back surfaces of the pipes, as well as the effect of this variation on heat transfer fluid (HTF) outlet temperature. The difference in the HTF outlet temperature and heat transfer rate between experimental data and CFD results has been identified. After rigorous examination, it has been observed that the effective range of length for heat absorbing pipe is from 60 to 600 mm (outlet) as HTF continues to absorb heat in this range. The average heat transfer rate was observed to be around 14108 W. Finally, the effect of variable mass flow rate over thermal efficiency of the receiver has been examined and it has been observed that once the mass flow rate exceeds 0.06 kg/s, further increasing the mass flow rate has little effect on improving the thermal efficiency because after an optimum value of mass flow rate would result in increase in heat loss from the pipe's back wall. In the present study, the results of the CFD analysis have been validated with an experimental test data.