摘要：The objective of present study is to investigate the effect of a novel type of insertion, i.e. semi-annular and fin shape metal foam (SAFM) hybrid structure on thermohydraulic and thermodynamic performance of absorber tube in parabolic trough collector (PTC). The influences of SAFM fin shapes (rectangle, triangle and trapezoid) on turbulent forced convection heat transfer and flow under non-uniform heat flux are numerically analyzed. The local thermal non-equilibrium method is adopted to reflect the energy imbalance between fluid and metal foam structure, and Monte Carlo Ray-Trace Method is used to determine the non-uniform heat flux on absorber tube wall. The results show that the insertion of SAFM improves thermohydraulic and thermodynamic performance of absorber tube; compared with smooth tube, Nusselt number is increased by 256.3%–838.7%, friction factor is increased by 440.3%–788.8%, and performance evaluation criteria increment, total entropy generation reduction as well as exergetic efficiency increment maximally reach 360%, 93.3% and 10.2% respectively. It is also found that SAFM achieves higher performance than individual semi-annular metal foam or fin shape metal foam, and SAFM with triangular fin achieves higher performance than that with rectangular or trapezoidal fin.
关键词：Parabolic trough solar collector ; Semi-annular metal foam ; Fin shape metal foam ; Turbulent forced convection ; Non-uniform heat flux
