Numerical investigation on thermal-hydraulic performance of a spiral plate heat exchanger

Abstract

The thermal-hydraulic performance of counter-current spiral plate heat exchanger (SPHE) under laminar flow regime is numerically investigated by adopting computational fluid dynamics (CFD) and field synergy principle in this paper. The effects of number of turns of spiral and Reynolds number on the average Nusselt number, heat transfer effectiveness, and Euler number are evaluated. The evidence shows that stronger convective heat transfer takes place at inner turns and areas around inner walls of channel. The heat transfer effectiveness increases with reducing increment and Euler number increases with increasing increment as the number of turns increases. When Reynolds number increases, both of heat transfer effectiveness and Euler number decrease due to large increments in mass flow rate. Consequently, an increase in number of turns of spiral at higher Reynolds numbers results in a greater benefit and a lower increment in cost. The numerical results in current research are also compared with the published article. It is found that the effect of thermal resistance of walls plays a vital role in evaluating the relation of heat transfer effectiveness and number of transfer units (NTU) at higher Biot numbers.