Revamping of Heat Exchanger Network of an Egyptian Refinery Plant using New Temperature Driving Force (TDF) Graphical Technique

Abstract

This paper introduces a new graphical approach for revamping of existing heat exchanger networks (HENs) based on pinch analysis rules. The HEN is represented on a simple graph, where the cold stream temperatures are plotted on the X-axis against the driving forces for each exchanger plotted on the Y-axis. This graphical technique can describe the energy analysis problems in term of temperature driving force inside the heat exchanger, which is an important factor in the revamping process as the differences in these driving forces are involved in calculating the area of heat exchangers, and consequently affecting the revamping cost. Also, each exchanger is represented in this graph as a straight line with a slope related to the heat capacity flows and length as function of the heat duty. An algorithm for revamping is also proposed.
The temperature driving force new representation is applied on an existing HEN in an Egyptian refinery (EORU) to boost its energy efficiency. The graphical revamping in application on the HEN shows savings of approximately 10 % in the energy demand with minor structural modifications.