Optimization of scale formation rate in heat exchangers using thermohydraulic theory

Abstract

In this research, utilizing the concepts of thermohydraulic theory, optimization of cost due to the scale formation in heat exchangers. The objective function involves the minimization of the energy consumption and production losses. First, via ASPEN we simulated shortcuts of exchangers in order to examine the effects of temperature and velocity on the scale formation. The project optimization was done by GAMS and due to the presence of nonlinear terms in the scale rate equations using CONOPT solver. For better results, Heat Exchanger 4131 and 4132 in Khorasan petrochemical Co. urea unit were used.The investigation shows that for the twin exchangers under study, first, the scale formation reduces cooling water flow by up to 40% in E4132. Second, the optimal values for minimizing cost of scale formation in the exchangers occurs at a cooling water flow rate of 152442.75 kg/h for the exchanger 4132 to reduce the cost by 15%.

Keywords

• thermohydraulic theory
• scale
• heat exchanger
• modeling
• optimization