螺旋折流板换热器在常减压蒸馏装置中的应用

换热器的选型不仅影响到换热网络的能量回收,还会对常减压装置的长周期稳定运行产生重要影响.通过对壳程介质分别为柴油、脱前原油、常压重油、减渣急冷油和减压渣油的工艺流体进行螺旋折流板换热器（采用HelixTool程序）和弓形折流板换热器（采用HTRI 6.0软件）的工艺计算,对比发现,螺旋折流板换热器壳程的单位压力降传热系数更高.同时结合螺旋折流板换热器能够降低壳程结垢和振动风险、延长设备运行时间等自身特点,考虑了油品性质及价格因素影响,可为常减压蒸馏装置在选择合适的部位采用螺旋折流板换热器提供参考.以某厂脱前原油-初顶油气换热器为例,计算结果显示采用螺旋折流板换热器可将换热器壳径减小200 mm,重量减少约28％.可见,螺旋折流板换热器具有明显优势,既保证了工艺性能,又降低了设备投资.

Application of helical baffle heat exchanger in atmospheric-vacuum distillation unit

The selection of heat exchangers will not only affect the heat recovery of heat exchanger train but also impact the long-term stable operation of the atmospheric-vacuum distillation Unit.The process calculations have been made for the helical baffle heat exchanger （HelixTool Program） and segmental baffle heat exchanger （HTRI6.0 Software） with diesel,undesalted crude oil,atmospheric heavy oil,vacuum quench oil,vacuum residue as the flow media in the shell side.The comparison of calculation results have found that the shell side of helical baffle heat exchanger has a higher heat transfer coefficient under a unit pressure drop.In addition,the helical baffle heat exchanger can reduce the fouling of shell side and vibration,extending the operation cycle of equipment.All these have provided a good reference for the selection of helical baffle heat exchanger for an appropriate service.In a case study of un-desalted crude oil/preliminary tower overhead oil vapor heat exchanger of a refinery,the calculation results show that the diameter of heat exchanger shell can be reduced by 200 mm and the weight can be lowered by 28％ if helical baffle heat exchanger is installed.Therefore,the helical baffle heat exchanger offers obvious advantages in reduction of investment while maintaining performances.