多点法测定可燃物质自燃特性的可靠性研究

Study on the multipoint method for analyzing the self-ignition characteristics of the combustible material

多点法是一种新提出的自热反应动力学分析方法。采用实验研究和理论分析相结合的方式对多点法的操作过程以及实验结果的可靠性展开研究。通过构建一维导热系统、采用不同形式的热电偶布设方式,对烟叶粉末的自燃临界环境温度、活化能以及反应热与指前因子的乘积等参数进行了测定。研究表明:所构建的一维系统能较好地模拟一维导热;热电偶的分布方式对测量结果有较大影响,对称分布状况下,温度结果与经典的F-K对称模型一致;多点法相比于传统方法省时省力,测定结果有较好的线性拟合相关度,求解的动力学参数较为可靠。

The multipoint temperature method is a new method for exploring self‐ignition kinetics .In this paper ,we used this method to conduct self‐ignition tests in order to testify its reliability by experimental study and theoretical analysis . By establishing a one‐dimensional heat conduction system and varying the thermocouple locations , the critical self‐ignition temperature ,activation energy and the product of reaction heat and pre‐exponential factor of tobacco powders were determined . It was shown that the thermocouple distribution was important for the experimental results .Under the symmetrical distribution of thermocouples , the results were in accordance with the classical F‐K temperature model . As compared to traditional methods ,the multipoint method is time saving and can be used to accurately determine the kinetic parameters of self‐heating .