Characterization of the Performance of Coupled Heat Exchangers With an Intermediate Heat Load

Abstract

Heat exchanger design is both an art and a science. The science part of it is premised on the fundamentals of convective and conductive heat transfer and the art part of it is based on determining how to effectively package the design to meet the process requirements with cost constraints. This paper is not concerned with the art portion of heat exchanger design. Rather, the paper presents a method of characterizing the performance of coupled heat exchangers with an intermediate heat load in process systems. In process plants, it is not uncommon to see heat exchangers that are coupled. Determining the performance of such heat exchanger arrangements can be daunting, but not insurmountable. Using first principles equations, engineers iteratively establish the performance of the heat exchanger arrangement. This process is time consuming. In this paper, we present a specific case of two coupled heat exchangers with an intermediate heat load in the intermediate system. The resultant model allows an engineer to perform sensitivity studies of the arrangement prior to investing resources in an actual design of the system. This method is expected to facilitate the process of examining the performance of similarly configured heat exchanger arrangements. Similar techniques can be used to simplify more complex heat exchanger arrangements.