A considerable improvement of heat transfer efficiency is obtainable by inserting an impermeable tube into a laminar counterflow concentric circular heat exchanger with external recycle under uniform wall fluxes. The mathematical formulation has been developed theoretically and the analytical solutions were achieved by combining a homogeneous solution and an asymptotic solution. The calculating results are represented graphically and are compared with those in a single-pass device and previous work [29]. The influences of subchannel thickness ratio and recycle ratio on the heat-transfer efficiency improvement and power consumption increment were also discussed in this study.
Relation:
淡江理工學刊=Tamkang journal of science and engineering 12(3)，頁231-238
