Investigation on the thermal-hydraulic performance in a PCHE with airfoil fins for supercritical LNG near the pseudo-critical temperature under the rolling condition

In this study, thermal and hydraulic performance of supercritical liquefied natural gas (LNG) is numerically studied in a printed circuit heat exchanger (PCHE) with airfoil fins under a rolling condition. Effects of operating pressures and rolling parameters are investigated. Results indicate that the PCHE has better thermal performance but worse hydraulic performance at a lower pressure condition. The instantaneous Nusselt numbers and the instantaneous Darcy friction factors present quasi-sine patterns against time, with a period same as the rolling period. The rolling condition gives larger time-averaged Nusselt numbers and Darcy friction factors, compared with the static condition, and the thermal and hydraulic performance increases with increasing rolling amplitude and rolling frequency. However, the rolling amplitude has a prevailing effect on the performance, in comparison to the rolling frequency.