Jiaze Ma

Simultaneous Optimization of Cooler Network, Pump Network, and Cooling Tower

This paper presents a model for optimizing the cooler network, pump network, and cooling tower simultaneously. Each part of cooling water system interacts with each other. However, most of previous works focus on the optimization of stand-alone components. In order to find the optimal structure, all of three parts are supposed to be optimized simultaneously. The series-parallel configuration of cooler network is presented in this paper. The pressure drop of cooler is treated as optimization variable. The coolers’ heights are considered and auxiliary pump network is employed to reduce pumping cost. Besides, the cooling tower capital and operational costs are taken into account. The most important variables include water inlet and outlet temperature, water flowrate and air flowrate. The MINLP (mixed-integer nonlinear programming) problem is formulated so as to minimize the total annual cost of overall cooling water system. A case from refinery is employed to verify the effectiveness of proposed model.