Abstract: 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 atthe 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.

Key words: hot spot, tert-butyl peracetate (TBPA), computational fluid dynamics (CFD), thermal runaway, divergence criterion