Abstract: This paper presents the optimization strategies of energy utilization in refineries base on transferring high temperature intermediate streams between units, such as optimizing energy consumption of individual processing unit, properly adjusting heat exchange network and integrating the heat utilization among units. The aim is to impel energy saving from units to the whole system optimization. The proposed strategy was applied to one CDU and FCC unit modification case. The result shows that the energy consumption of upstream and downstream units is decreased. Because the intermediate stream is fed straightly, the energy consumption of intermediate product tank and circulating fund of the storage and transportation are reduced. Changing or adding heat exchanger and pipe-line is just needed in this revamping case. The total investment is 10.14 million RMB, but the economic benefit is 22.52 million RMB annually, thus the capital pay-off time is less than 6 months. It is demonstrated that the energy optimization base on transferring hot feed between units is a way of low input and high output, which is significance for the coming turn of energy saving.

Key words: hot feed, energy optimization, strategy, heat integration