Abstract: The type selection of overhead heat exchanger of FCC main fractionator is critical to the recovery of low temperature heat and the reduction in power consumption of wet gas compressor. Taking a 2.2 Mt/a RFCC unit as an example, the PROII and HTRI software are used to compare the heat transfer efficiency, EMTD and pressure drop of different kinds of overhead heat exchangers. The results indicate that fixed tubesheet heat exchanger provides lower pressure drop and higher heat transfer efficiency. PVDesktop software is used to carry out thermal stress analysis for some special locations of the fixed tubesheet heat exchanger, and the results show that fixed tubesheet is suitable for the overhead heat exchanger due to its good stress conditions, easier manufacture and lower metal consumption. This paper provides some useful reference for the type selection of overhead heat exchange systems in the fractionators of delayed coker, hydrogenation unit and other units in refinery

Key words: catalytic cracking/FCC, overhead heat exchanger of fractionator, fixed tubesheet