Design and characteristics of a novel tapered tube bundle receiver for high-temperature solar dish system

Most of current receivers for high-temperature (>1000 K) solar thermal utilizations were confronted with non-uniform solar flux distribution on absorbers, which would result in cracking and melting as well as flow instability. This paper proposes a new design of tapered tube bundle receiver (TTBR) by investigating the geometrical principle of dish concentrators, which makes each passage of the absorber parallel with the concentrated sun rays to absorb uniform solar thermal. The performance of the new design was confirmed using the theory of energy balance, Ray-tracing simulation and CFX simulation. Calculations based on the theory of energy balance indicated that the thermal efficiency of TTBR achieves 80%. Ray-tracing simulation results showed that solar rays are able to irradiate the entire tubes and uniformly distribute on each tube. And according to the flow field simulation by CFX, attributed to the circumferential inflow structure, almost equivalent air mass rate was obtained in each tube, indicating the designed TTBR receiver can achieve uniform flow in the absorber passages, which laid a good foundation for the further stable and efficient heat transfer procedure.