Advanced pinch technology based composite curves for evaluating the usable excess heat potential

Paper in proceeding, 2005

This paper describes the application of a set of advanced composite curves to evaluate the potential to release usable excess heat (hereafter referred to as Qxs) from an existing process industry. Throughout this paper Qxs is defined as heat at enough high temperature to be interesting for use e.g. for district heating. Studies using the advanced curves reveal information about the existing HEN that traditional graphical methods are not able of, and that for almost the same collected information from the process. This allows for estimations on the heat recovery potential and existing pinch violations before detailed calculations. These curves have earlier been presented in connection with integration of CHP, HP and retrofitting HEN’s. The curves have also been used to evaluate the Qxs potential in one doctoral thesis, but the methodology was not explained in detail, but rather used as a tool among many. In this paper we broaden the discussion on how to use the curves, which traps there might be and how to interpret and use the results. Important questions that are answered are for example: • How does the Qxs potential change when the pinch temperature changes? • At which temperature is it possible to release Qxs? • How could the Qxs be made available? • How can the Qxs potential be revealed?