液氮浴中不锈钢板动态冷却过程试验及模拟分析

Experiments and numerical simulation of dynamic cool-down process of stainless steel plate in liquid nitrogen bath

以液氮为介质,通过测量不锈钢平板试件在液氮浴中的动态温度分布,在实测降温曲线同根据经验公式模拟得到的降温曲线进行对比的基础上,对低温沸腾换热过程中临界热流密度和最小膜态沸腾热流密度所对应的温差进行了修正,为更准确地模拟深冷处理中的降温过程提供了指导。利用修正参数对不锈钢平板进行了模拟分析。

With liquid nitrogen as coolant, a stainless steel plate emerged into the bath has been observed for dynamic temperature profile. The calculated results based on the experiential equations summa- rized from literatures with the measured cool-down curves. Some revisions have been made for the temperature differences corresponding to the critical heat flux density and minimum film boiling heat flux density re- spectively. The revised experiential equations of heat transfer coefficient help to simulate and analyze the dynamic heat transfer more accurately during the cryogenic treatment. The numerical simulation with revised parameters was carried out for the stainless steel plate.