热点对过氧乙酸叔丁酯热失控过程的影响研究

Influences of hot spots on thermal runaway process of tert-butyl peracetate

为预防热失控,使用Fluent软件对工业尺度的反应釜进行计算流体动力学(CFD)模拟,探究热点对过氧乙酸叔丁酯(TBPA)热失控过程的影响。以系统散度判据为热失控临界判据,以热动力学和热分解产物分析结果为参数设置依据,使用多重参考系模型模拟反应釜内搅拌桨的转动,模拟分析液区顶部、1/4、1/2、3/4高度处和底部瞬时热点对热失控过程的影响。结果表明:瞬时热点使系统热失控大大提前;底部热点能够最快造成整体热失控,危险性最大;建议在液区顶部距轴线约1/2半径处和搅拌桨下部滞留区同时设置温度传感器,能够快速检测到可能存在的热点,避免发生热失控。

For the sake of preventing thermal runaway,the Fluent software was applied to execute CFD simulation of an industrial scale reactor to explore the influences of hot spots on the thermal runaway process of TBPA.The divergence criterion was adopted as the critical criterion for thermal runaway. Physical parameters of TBPA thermal decomposition were set on the basis of analytical results of the thermal dynamics and the decomposition products.Multiple reference frame model was used to simulate the rotation of the agitator in the reactor.The effects of transient hot spots at the top,1/4,1/2 and 3/4 liquid height of the reactor and the bottom on the thermal runaway process were respectively investigated.It is found that thermal runaway of the system will advance greatly when there are hot spots,that hot spot at the bottom triggers off global thermal runaway fastest,the most dangerous situation,and that rapid detection of local thermal runaway caused by possibly-existed hot spots requires setting two temperature probes,one at the top zone of the liquid having a distance (to the axis)being approximately 1/2 of the radius and the other one in the retention area below the agitator.