Direct contact membrane distillation: effect of mass transfer on heat transfer

A new heat transfer model is proposed. The model can identify the effect of mass transfer on heat transfer across the thermal boundary layers at the feed side (q(f)(m)), the permeate side (q(p)(m)), and inside the membrane (q(v)). The simulation results show that the Dufour effect on the feed side is higher than that on the permeate side. The maximum values of q(f)(m) and q(p)(m) were 12.9 and 4.0%, respectively, q(p)(m) can he neglected under all conditions considered and q(f)(m) can be neglected at low feed temperatures. q(v) is a major component of heat transfer inside the membrane. A simplified heat transfer model in which q(f)(m), q(p)(m), and q(c), were not considered showed excellent agreement with the proposed full heat transfer model. (C) 2001 Elsevier Science B.V. All rights reserved.