The "Pinch Analysis": Special Cases

A method for determining the efficiency and scope for improvement of a process plant's energy consumption, based on pinch technology, is reviewed. While this is a generic approach that applies in most cases, there are certain cases where the results are not clear cut. This paper identifies three cases which deviate from the norm. The first case considers a process with no process-process heat exchangers and explains its relevance in relation to "pinch parameters". The second case examines the streams of a process, the temperature range of which is not a continuum, and shows the consequences on pinch parameters. In the third case an algorithm is introduced which treats the potential energy savings from utilizing a utility "waste" stream, such as low pressure steam or condensate, the quantity of which is dependent on the quantity of source utility