焦化装置换热网络优化效果分析

Study on optimization of heat exchanger train for delayed coking unit

受装置处理量及换热流程分布的影响,焦化装置原有的换热网络热量输出不能满足下游装置生产要求,同时还有部分低温热量未能得到充分利用。通过建立换热网络模型,利用跨越夹点及交叉传热分析及换热网络集成优化技术对换热流程进行调整和重新匹配,充分利用多余热源和原来没有利用的低温热,在满足下游装置生产要求的同时提高原料进入加热炉的换热终温。采用超声波防垢技术对主要换热设备进行了污垢预防,改造后焦化装置节能效果显著,降低能耗约61.36 MJ/t,年经济效益约800×104RMB$。

Because of the impact of unit capacity and heat exchanger train design,the heat output of heat exchange train of the delayed coking unit could not meet the requirement of the downstream process units.Further more,part of low-temperature heat of the delayed coking unit had not been fully utilized.The model of heat exchange train has been established,and cross pinch point and cross heat transfer analysis as well as integrated optimization technology of heat exchange train are applied to fully use the surplus heat and low-temperature heat.The end heat exchanger temperature of the heater is raised by utilization of surplus heat sources and low temperature heat.In addition,ultrasonic fouling prevention technology has been used for the fouling of main heat exchange equipment.After revamping of the delayed coking unit,a large amount of energy has been saved,i.e.about 61.3 MJ/t,and annual economic benefit from energy saving is about 8.0 million Yuan RMB.The energy-saving objective has been achieved.