investigation of crude oil fouling on performance of preheat exchangers of crude distillation unit (cdu)

in this article the effect of fouling on tube side and the overall performance of preheat exchangers of crude distillation unit of petroleum refinery have been investigated. for this purpose the experimental data of australian light crude oil in surface temperature of 200-260oc and the velocity between 0.25 to 0.4 m/s have been used. first, an overall dirty heat transfer coefficient was calculated and then the thickness of scales was determined. by solving heat transfer equations numerically for both cases of dirty and clean conditions, the temperature distribution for the crude oil running inside the heat exchanger's tubes was obtained. finally, the effects of fouling on the exit temperature of process fluid and the pressure drop have been investigated