中文摘要：

为揭示海拔对保温材料火蔓延特性的影响,通过在高原环境的拉萨和平原环境的合肥进行一系列保温材料发泡聚苯乙烯（EPS）和挤塑聚苯乙烯（XPS）火蔓延对比试验,研究材料的放置角度以及大气压力和氧气浓度对其火蔓延过程中温度场的影响。研究结果表明,火蔓延过程中,温度场的温度梯度以及高温区域的面积是影响火蔓延速度的主要因素。就EPS而言,在两地火蔓延过程中,其火蔓延速度均随着放置角度（-30～30°）的增加而增加;而对XPS,在拉萨低压低氧环境中,其火蔓延速度却呈现出随负放置角度（-30～0°）的增大而减小的特点,这主要是受火蔓延过程中特有温度场特性的影响,进而影响其热解前锋的传热量。

英文摘要：

In order to reveal the effects of altitude on the flame spread characteristics of PS, a series of flame spread experiments were carried out on plateau area of Lhasa and in plain area of Hefei. The effects of inclined angle and atmospheric pressure and oxygen concentration on the temperature field were observed. The results show that during the flame spread process, the temperature gradient and the area of high temperature are the main factors influencing the flame spread speed,that for the EPS, both in Lhasa and Hefei, the flame spread speed increases with the increased inclined angle（ -30 -30°） , and that for the XPS, in the hypobaric hypoxia environment of Lhasa, the flame spread speed decreases with the inclined angle（ -30 -0°） ,which is affected by the the heat transfed to the pyrolysis front. characteristics of temperature field that contributes to