This paper presents the energy and exergy analyses for a delayed coking unit in a Chinese refinery using the three-link energy structural model. According to the results of energy-use analysis and evaluation, the potentials of energy-use and improvements for energy-savings as well as detail procedures are suggested. The proposed improvements are expected to remarkably lower the energy consumption and to improve the economic profits of the delayed coking unit. Compared to the original unit, the energy consumption of the improved flowsheet decreased by 37.2%, which demonstrates that the applied strategies are suitable for the energy-use analysis and improvement of process systems. (C) 2004 Elsevier Ltd. All rights reserved.