热管搅拌反应釜内综合性能的数值模拟

Numerical simulation of the overall performances in the heat pipe agitated reaction vessel

将热管技术应用于高放热搅拌反应釜,用椭圆截面热管代替矩形挡板。以糖精钠生产中酰胺化工序中的反应为依托,设计出新型热管搅拌釜。基于ANSYS中Fluent模块,编写热量源项用户自定义函数(UDF),以表征搅拌过程中釜内液体实际散热状况,采用数值模拟的方法,综合考察3个结构参数和搅拌转速对釜内最优温度持续时间、搅拌混合均匀时间等性能参数的影响。搅拌转速对釜内性能影响的权重远大于3个结构参数,就最优温度持续时间而言,搅拌器安装角度>热管中心线到釜壁距离>搅拌器下层桨到釜底距离;就搅拌混合均匀时间而言,搅拌器下层桨到釜底距离>搅拌器安装角度>热管中心线到釜壁距离。同时模拟出单个因素对搅拌釜性能的影响,并分别优选出热管中心线到釜壁距离为85mm,搅拌器下层桨到釜底距离为340mm,搅拌器安装角为0°,搅拌转速为240r/min。

This research applied the heat pipe technology in the highly exothermic agitated reactor and replaced the rectangle baffles were with elliptical heat pipes. A new structural heat pipe agitated vessel was designed based on the amide reaction in the production of the saccharin sodium. Using Fluent module in ANSYS the User Defined Function（UDF） was obtained to express the actual heat dissipation of the reacted liquids. Numerical simulation analyzed three structure parameters and the rotor speed comprehensively , in order to evaluate the effects of these factors on the optimal temperature duration time,mixing uniformity time and other performance parameters. The results showed that the rotor speed had considerably great impacts on the performance parameters of the stirred tank. The installing angle of the stirrer had the greatest impacts on the optimal temperature duration time;the distance between the lower blade and the reactor bottom had greatest impacts on the mixing uniformity time. The impacts of each factor on the stirrer performances were also analyzed through the numerical simulation. The optimal conditions were：135mm for the distance between the heat pipe center line and the reactor wall,340mm for the distance between the lower blade and the reactor bottom,0＆#176; for the installing angle of the stirrer, and 240r/min for the rotor speed.