多组扭曲片排布方式对乙烯裂解炉管内产物收率的影响

针对乙烯裂解炉炉管内置入不同组数扭曲片对裂解产物收率的影响进行数值模拟，选用石脑油为裂解原料，得到不同管型的温度分布、乙烯等产物质量分数的分布情况。结果表明，扭曲片可有效降低管壁与核心流体间的温度梯度，且出口段置入3组扭曲片的炉管换热效果最佳；炉管中乙烯与丁二烯的产率沿轴向距离线性增加，丙烯产率在反应后期的出口段下降；入口段置入2组、出口段置入3组扭曲片的L2R3型炉管具有较高的三烯收率，是光管的1.29倍。

Effect of arrangement of multiple groups of twisted slices on product yield in ethylene cracking furnace

The production of ethylene by cracking furnace is the most commonly used method in industrial and furnace tube is the main place where cracking reactions occur. The internal components of the twisted slices are added to furnace tube and the purpose is to improve the coupling between the flow field and the temperature gradient field, so as to enhance the heat exchange of the fluid and to promote the increase of products in the cracking reaction. U-shaped tube of ultra-selective cracking furnace was selected as the research object, based on naphtha cracking raw material. The furnace tubes were built into different multiple groups of twisted slices for numerical simulation to obtain the temperature distribution and the mass fraction distribution of ethylene and other products. Simulation results showed that the twisted slices can effectively reduce the temperature gradient between the tube wall and the core fluid, and the heat exchange effect of the furnace tube with 3 groups of twisted slices placed in the outlet section was the best. The yield of ethylene and butadiene in the furnace tube increased linearly along the axial distance, while the yield of propylene decreased at the exit stage in the later period of reaction. The L2R3-type tube with two twisted slices placed in the inlet section and three twisted slices placed in the outlet section had higher yield of triene, which was 1.29 times that of the smooth tube.