Effects of fouling on performance of retrofitted heat exchanger networks: A thermo-hydraulic based analysis

The energy recovery performance of crude pre-heat trains (PHTs) in oil refineries is typically impaired by deposition over time of fouling on the thermal surfaces. Such time varying effects are normally not considered in the design or retrofit of heat exchangers networks. In this paper, the importance of taking into account such effects is demonstrated, bymeans of a case study. An existing industrial PHT network is vailable online 26 January 2011 eywords: rude oil fouling efinery pre heat train eat exchanger network simulated using a dynamic, distributed mathematical model for shell-and-tube heat exchangers undergoing crude oil fouling. To systematically assess the impact of fouling at the network level, several key performance indicators are proposed and used to analyse three retrofit options aimed at maximising overall heat recovery. Simulation results show that network designs that maximise energy recovery at steady state are not the bestwhen fouling occurs. It is concluded that a proper retrofit designmust include ying hell and tube heat exchanger odelling consideration of time var