Maximum entropy generation of in-series connected heat exchangers

Theoretical analysis of entropy generation and availability destruction of "n" similar cocurrent or countercurrent heat exchangers connected in series are presented. A criterion for comparing the relative performance of any n umber of in-series connected similar heat exchangers is developed. The effe ct of different influencing parameters such as the number of connected heat exchangers, the individual effectiveness of each unit, the heat capacity r ate ratio and flow arrangement on the quality of heat exchange are presente d. It is found that, the maximum of availability destruction (maximum entro py generation) for in-series-connected similar cocurrent heat exchangers is obtained at epsilon* = 1/(1 + delta). However, for counter-current heat ex changers connected in-series; epsilon(n)* = 1/(Sigma(i=o)(n) delta(i/n)). T his analysis might be useful for a proper choice of the number of heat exch angers to be connected together and the choice for the best operating condi tions. Copyright (C) 2000 John Wiley & Sons, Ltd.