Effect of External Recycle on the Performance in Parallel-Flow Rectangular Heat-Exchangers

[[abstract]]The analysis of heat transfer in the heat exchangers of cocurrent and countercurrent flows with external recycle, has been carried out by heat-transfer theory. Considerable improvement is achievable by recycle operation if the increase in heat-transfer coefficient by applying the recycle effect to enhance the fluid velocity, can compensate for the decrease in the driving force (temperature difference) of heat transfer due to the remixing of inlet fluid. As expected, the heat-transfer rate obtained in the countercurrent-flow heat exchangers with or without recycle are superior to those in the cocurrent-flow devices. However, the space for the improvement in performance by recycle in the countercurrent-flow device is smaller than that in the cocurrent-flow one.[[notice]]補正完畢[[incitationindex]]SCI[[incitationindex]]E