基于COMSOL Multiphysics的金枪鱼罐头热杀菌过程数值模拟

Simulation of Thermal Sterilization for Canned Tuna Using COMSOL Multiphysics

以COMSOL Multiphysics软件为基础,建立纯传导和固液混合两种模型来模拟金枪鱼罐头的热杀菌过程。通过无线温度传感器检测热杀菌过程中130 g金枪鱼与55 g,4%Na Cl卤水罐头中心温度的变化,结果发现：固液混合模型的预测结果与试验数据十分吻合,而纯传导模型明显低估了罐内温度传递。在此基础上,用固液混合模型模拟工业杀菌条件（10 min-60 min-10 min/116℃）下金枪鱼罐头内的温度分布、速度分布及致死率值,结果发现最慢加热区（SHZ）位于罐高的22.9%-50%之间,最慢冷却区（SCZ）位于罐高的50%-81%处。在升温和降温阶段,罐内液体流速可达4.41 mm/s。杀菌结束时罐内最大与最小致死率值相差4.93 min,而中心点致死率与最小致死率相差很小。本文建立的模型可为金枪鱼罐头的热杀菌优化提供参考。

The simulation during thermal processing of canned tuna based on pure conduction and solid-liquid mixture model using COMSOL Multiphysics is the subject of this paper. Experiments were run with 130 g tuna fish and 55 g of 4% Na Cl brine in several metal cans and the temperature of centre point were determined by the wireless temperature recorder. Results obtained by COMSOL Multiphysics for temperature profiles using solid-liquid mixture model were in good agreement with experimentally determined values and the heat transfer rate was underestimated significantly by pure conduction model. After validation of the mixture model, further simulations were carried out for the temperature distribution, the velocity profile and lethality in the can under the condition of industrial sterilization（10 min-60 min-10 min/116℃）. The slowest heating zone and the slowest cooling zone were located at a height of about 22.9% ~50% and 50~81%of the can height from the bottom respectively. The maximum velocity in heating and cooling stage was about 4.41mm/s.At the end of sterilization, the difference of lethality between the maximum and minimum was 4.93 min, but the lethality in center point was very closely to the minimum lethality in the can. This study is expected to be a significant contribution for further optimization studies.