Thermodynamic optimization of geometric structure in the counterflow heat exchanger for an environmental control system

This paper shows that the internal geometric configuration of a component c an be deduced by optimizing the global performance of the installation that uses the component. The example chosen is the counterflow heat exchanger t hat serves as condenser in a vapor-compression-cycle refrigeration system f or environmental control of aircraft. The optimization of global performanc e is achieved by minimizing the total power requirement or the total entrop y generation rate. There are three degrees of freedom in the heat exchanger configuration, which is subjected to two global constraints: total volume, and total volume (or weight) of wall-material. Numerical results show how the optimal configuration responds to changes in specified external paramet ers such as refrigeration load, fan efficiency, and volume and weight. In a ccordance with constructal theory and design [1], it is shown that the opti mal configuration is robust: major features such as the ratio of diameters and the flow length are relatively insensitive to changes in the external p arameters. (C) 2001 Elsevier Science Ltd. All rights reserved.