Effect of network arrangement on the heat transfer area of cooling networks

Abstract

This work presents a study of the effect of the configuration of cooling networks upon the total exchanger area. Most industrial installations have cooling systems whose network of exchangers exhibit parallel arrangement. From the operation point of view, in this arrangement cooling water enters every unit at the same temperature. There are cases, however, where not all exchangers require water at the same cold temperature; therefore, it is possible to generate different arrangements with positive results in terms of equipment size and therefore capital investment. In this work, various cooling network design approaches are analysed subject to restrictions such as the maximum permissible water return temperature and pressure drop. Results show that when exchangers are designed for maximum utilisation of the allowable pressure drop or the maximum allowable fluid velocity, the series arrangement results in lower heat transfer area and lower investment. In the case of existing cooling networks, a practical approach for the minimisation of power consumption is implemented by taking advantage of the installed network area. The procedure is demonstrated using a real case study.