Numerical Research on the Heat-Transfer Enhancement of Printed Circuit Heat Exchanger in the Presence of Pulsating Flow

Abstract

This paper presents a numerical investigation on the flow and heat-transfer characteristics of liquid lithium and helium in printed circuit heat exchanger (PCHE) channels with pulsating flow introduced. The effects of the mass flowrate of helium, frequency, and amplitude of pulsating flow were examined, respectively. The findings indicate that the introduced pulsating flow has a positive effect on heat transfer at a lower Reynolds number. With the increase of pulsating frequency, the heat-transfer enhancement may decline, and the pressure drop is reduced, with Colburn factor (j) and Fanning friction factor (f) varying marginally. In the flow state with enhanced heat transfer, keeping a lower pulsating frequency, the heat-transfer enhancement ratio E(h) exhibits an approximately linear increase with the pulsating amplitude. Meanwhile, the average pressure drop, Colburn factor (j) and Fanning friction factor (f) also increase with the amplitude, with the fluctuation amplitude of each parameter directly proportional to the amplitude.