摘要
基于热力学定律以及燃烧化学反应动力学,考虑反应生成物所带来的热力学效应和木质粉尘的吸热效应,构建了木质粉尘燃爆的热力学自洽动力学理论模型。利用该模型对不同粒径和不同浓度的木质粉尘燃爆试验数据进行了模拟仿真,并与已有理论模型进行了对比。结果表明,在20 L爆炸球内反应生成物以及木质粉尘的吸热均随温度的升高迅速增加,最大爆炸压力值随之降低;采用本理论模型计算得到的最大爆炸压力与试验测量数据高度吻合,成功解决了已有模型存在的问题。此外,利用本理论模型计算了20 L爆炸球内气体的分子间距。在整个爆炸过程中,气体分子间距与分子直径的比值处于10.6~11.2区间内,即分子间距一直保持在分子直径的10倍以上,满足理想气体模型对气体分子间距的要求,充分证实了本研究所构建理论模型的热力学自洽性。本研究结果对除尘器、加料仓及传输管道泄爆面积的计算,以及相应隔爆装置的选择,对加工设备表面及管道内壁的热传感器和火花探测器的选择均有重要意义,对纤维板生产线中粉尘易爆设备的防爆和减灾技术研发具有理论指导价值。
According to the laws of thermodynamics and the dynamics of chemical reactions,a thermodynamic self-consistent dynamic model of wood dust explosion was developed by considering the thermodynamic effect of reaction products and the heat absorption effect of wood dust.The experimental data were simulated based on this model,and the simulation results were compared with those of the existing theoretical models.The results showed that,for the different wood dust concentrations and wood dust particle sizes,the heat absorption of reaction products and wood dust in 20 L explosion sphere increased with the rapid increase of temperature.Therefore,the maximum pressure of the wood dust explosion was decreased,which led to that the theoretical simulation results of maximum explosion pressure were highly consistent with the experimental data.The problem of large deviation between theoretical calculation and experimental data fitting in the existing theoretical models was solved successfully.At different dust concentrations,the maximum explosion pressure calculated by this model did not increase monotonically with the increase of dust concentration.As a matter of fact,the maximum explosion pressure reached a certain concentration in the middle,which was consistent with the test results.Under different dust particle sizes,the fitting degree of explosion pressure evolution and test data simulated by this model was much higher than that of the existing models,and the maximum explosion pressure value was very close to the measured data.Furthermore,the ratio of molecular distance to molecular diameter was calculated using the thermodynamic self-consistent dynamic model of wood dust explosion.During the whole explosion,the ratio was between 10.6 and 11.2,that is,the molecular distance remained more than 10 times of the molecular diameter.It was shown that the gas molecular distance satisfied the ideal gas model,which fully verified the thermodynamic self-consistency of this model.The results of the dynamic model research of wood dust explosion were of great significance to the estimation for the discharge area of the dust collector,the feeding bin and the transmission pipeline,the selection of the corresponding flameproof device,and the selection of the thermal sensor and spark detector on the surface of the processing equipment and the inner wall of the pipeline.The results of this study also had the theoretical merit for the research and development of explosion protection,and the disaster reduction technology of dust explosive equipment in the fiber board production line.
作者
胡涛平
喻孜
郭露
徐长妍
HU Taoping;YU Zi;GUO Lu;XU Changyan(College of Science,Nanjing Forestry University,Nanjing 210037,China;College of Materials Science and Engineering,Nanjing Forestry University,Nanjing 210037,China)
出处
《林业工程学报》
CSCD
北大核心
2019年第4期29-34,共6页
Journal of Forestry Engineering
基金
国家重点研发计划(2016YFD0600703-1)
江苏省研究生科研与实践创新计划(KYCX17_0841)
关键词
木质粉尘
粉尘燃爆
最大爆炸压力
动力学模型
热力学自洽
wood dust
dust explosion
maximum explosion pressure
dynamic model
thermodynamic self-consistency
