Modification of Preheating Heat Exchanger Network in Crude Distillation Unit of Arak Refinery Based on Pinch Technology

摘要

In this work, the Hint software that is based on methods of pinch technology was applied for design, optimizing and improving the integrated heat exchanger network of crude oil preheating Process in distillation unit in Arak refinery with the aim of heat load reduction in the furnace. In the first step, the data gathering of hot and cold streams in preheating section of distillation unit has been done and then by using Hint software, integrated heat exchanger network was designed with assumption of ΔT = 30k. Improving the existing heat - exchanger network has been done with respect to operating conditions and hydraulic limitation by considering the aim of least changes in the existing arrangement of exchangers, which is led to increasing of furnace inlet temperature up to 10.5°k and deceasing of heat duty of the distillation furnace about 9855 kw. The most important results in this project are: Decreasing of heat duty of distillation furnace to 9855 kw that leads to saving about 820000 US$ per year. Increasing the inlet temperature of the furnace up to 10.5°k. Decreasing the temperature of furnace tubes skin to 300°k. Decreasing the temperature of furnace flue gas to 290°k. Decreasing the greenhouse emission to 20000 tones per year.