某炼油厂催化裂化装置原料-油浆换热器管束存在堵塞问题，该换热器进行清洗期间，原料、油浆改走换热器副线，造成原料预热温度降低。分析了原料预热温度降低对剂油比、汽油烯烃含量、汽油辛烷值、产品分布和生焦的影响，结果表明，原料预热温度降低后，造成剂油比增大、汽油烯烃含量降低、轻收和总液收降低、生焦升高、产品分布变差。

There exists a clogging problem in the feedstock-oil slurry heat exchanger of the FCCU in a refinery.When this heat exchanger is being cleaned,the feedstock and oil slurry shift to flow through the backup lines,causing the temperature of the preheated feedstock to decrease.The effects of the temperature of feedstock preheating on the ratio of catalyst to oil,the content of olefins in gasoline,octane number of gasoline,products distribution and coke formation are analyzed.The results show that the ratio of catalyst to oil will increase,the content of olefins in gasoline will go down,the yields of light oil and total liquid will drop,the formation amount of coke will increase and the products distribution will get worse when the temperature of feedstock preheating drops.