Minimisation of fuel energy wastage by improved heat exchanger network design - An industrial case study

Abstract

Petroleum refineries fulfil their energy (process heat) requirement by direct fuel firing. In this regard, a heat exchanger network (HEN) is widely used to recover thermal energy that may be otherwise wasted. The HEN can significantly reduce the overall energy consumption in industrial processes. In many industrial processes such as oil refineries, crude oil needs to be heated to a required temperature. Here a study of a HEN problem of a crude oil distillation unit of an African Oil Refining Company (AORC) is carried out. In this unit the crude is required to enter the distillation column at 328°C, while the crude inlet temperature at the furnace is only 220°C. Therefore, a heater must supply heat to raise the temperature by a third of the target temperature. In this work pinch technology is used in the existing HEN in order to obtain a desirable energy saving and to identify the required additional modification. With the addition of only one heat exchanger and re-construction of the HEN, significant utility savings are achieved. © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.