Matrix Representation of the Grid Diagram for Heat Exchanger Networks

Heat Exchanger Networks (HENs) are commonly represented on grid diagrams (GD). However, the traditional GD has some drawbacks with regard to calculation and evaluation. In this paper a representation of HENs in the form of a matrix called HEN Steam Matrix (HENSM) is presented. This numerical way has some advantages over graphical representation. In HENSM the heat exchangers are arranged in orderly fashion making it easier for engineers during synthesis or retrofit analysis. HENSM is able to track temperature differences directly by numerical values. This reveals the Process Pinch, Network Pinch and the other potential Pinches. The matrix can also serve as an input and output interface for software tools. A retrofit case study is demonstrating the matrix use. The amount of energy can be recovered with different heat paths from the same heater to various coolers and the capital and payback period are compared among the heat paths.