催化裂化装置分馏塔顶换热器选用方案的比较分析

COMPARATIVE ANALYSIS OF SELECTION SCHEMES FOR OVERHEAD HEAT EXCHANGER OF FCC MAIN FRACTIONATOR

催化裂化装置分馏塔顶换热器选型对于分馏塔顶油气低温热量的回收以及气压机动力消耗的降低起到关键作用。以某2. 2 Mt/a重油催化裂化装置为例,采用PROII、HTRI等计算软件,对比了分馏塔顶油气-热水换热器采用固定管板式和折流杆式、BJ_(21)S型的传热效率、有效平均温差、压降等。结果表明:固定管板式换热器的压降更低,传热效果更优。针对固定管板式换热器的某些特殊部位,采用PVDesktop软件对其进行了热应力分析,结论是分馏塔顶油气-热水换热器采用固定管板式结构受力情况良好,制造难度更小,设备金属消耗量更低。为石油炼制企业延迟焦化装置、加氢装置等分馏塔顶油气冷凝冷却系统设备选型提供了参考。

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.