高温条件下热防护服边界条件确定方法及其非稳态导热预报方法

A method for boundary condition determination of thermal protective clothing and itsprediction method for unsteady state heat transfer under high temperature

为能够确定热防护服材料的非稳态隔热性能,在自然对流传热为主及人体皮肤热属性未知的情况下,文章提出一种确定非稳态自然对流换热系数及皮肤热属性的方法。首先建立了自然对流和辐射联合作用下的热防护服-空气层-模拟皮肤传热系统的非稳态导热方程;随后,利用有限差分法,提出了一种非稳态自然对流换热系数及皮肤热属性的计算模型,结合一次实验,确定了模型中的未知参数;最后,预报了4种工况下热防护服材料的非稳态导热特性。结果表明,计算值与实验值最大误差约为0.09℃,发生在初始传热阶段,所确定的热防护材料传热边界条是适宜的。

To determine unsteady heat insulation performance of thermal protective clothing materials,a method to determine free convection transfer coefficient and thermal properties of manikin skin was proposed in the condition where convective heat transfer was dominated and thermal properties of human skin were unknown.Firstly,the unsteady state heat transfer equation of thermal protective clothing-air layer-simulated skin heat transfer system was established under the joint action of free convection and radiation.Then,the finite difference method was used to propose a finite difference method of unsteady state free convection transfer coefficient and manikin thermal properties.The unknown parameters in the model were determined by an experiment.Finally,unsteady state heat transfer properties of thermal protective clothing were predicted under 4 working conditions.The results indicated that the maximum error between the calculated value and the experimental value was about 0.09℃,which happened at the initial heat transfer stage.Therefore,the heat transfer boundaries of thermal protective clothing are appropriate.