【摘要】 讨论了软质聚氨酯泡沫塑料对流判据的低温传热机理.根据软质聚氨酯泡沫塑料结构简图,将各种参数和低温数据带入对流判据公式,得到对流判据L的计算结果.计算了软质聚氨酯泡沫塑料的低温热导率.为了与计算的低温热导率比较,采用测试硬质泡沫塑料热导率的稳态热流双试样保护热板装置,测试了软质聚氨酯泡沫塑料的低温热导率,最后给出了低温热导率与温度关系曲线.根据试验,讨论了低温热导率的影响因素如温度、密度、吸水率等.更多还原

【Abstract】 The thermal transfer mechanism of flexible polyurethane (PU) foams at low temperature has been discussed. According to the structure model diagram of flexible PU foam,convection criterion L can be calculated when parameters and influences are considered at low temperature. The thermal conductivity of the flexible PU foam at low temperature can also be calculated. In order to compare with the calculated thermal conductivity,the thermal conductivity of the flexible PU foam at low temperature has been tested by means of the double-sample of guarded hot-plate apparatus in steady thermal flow which usually is used to test the thermal conductivity of the rigid PU foam. Finally,the curve of between temperature and thermal conductivity at low temperature has been obtained. Furthermore,according to the test,the change and influence factors (such as temperature,density,water absorption etc.) of thermal conductivity have been discussed.更多还原