Broadening the capabilities of pinch analysis through virtual heat exchanger networks

Abstract

The present paper proposes a technique to enlarge the capabilities of pinch analysis. Conventional pinch analysis is limited to heat exchange between streams of unchanging composition, whereas in reality, much heat exchange occurs in components such as chemical reactors, mixers etc. This can be overcome by introducing virtual heat exchangers that convert the considered components into equivalent heaters and coolers where the stream compositions remain unchanged. In this way, they are automatically taken into consideration in the current pinch analysis packages, which may lead to different and better optimisation. A client–server interface program has been written to introduce virtual heat exchangers after completion of the process analysis through Aspen Plus and before entering the pinch analyser Super Target. The application of virtual heat exchangers is next illustrated through a simple example for methanol synthesis.