摘要
为了深入研究镁铝合金粉尘非预混燃烧特性,在传统哈特曼管基础上进行了针对性的优化改进,采用模拟试验与CFD仿真相结合的研究手段,分别从粒径、质量流量和空气湿度3个方面对镁铝合金粉尘的燃烧特性进行了详细的研究。结果表明,80μm、120μm、150μm及270μm镁铝合金粉尘的平均反应温度分别为2 349.8 K、2 253.7 K、2 167.3 K和2 094.7 K。当粉尘质量流量一定时,单一颗粒粒径越大,颗粒与空气接触的比表面积则越小,燃烧反应温度越低;镁铝合金粉尘燃烧分为富氧和贫氧燃烧,粉尘与空气质量流量比45.54∶100为镁铝合金粉尘富氧与贫氧燃烧的临界点,当空气质量流量大于粉尘质量流量10倍时,氧气与镁铝合金粉尘接触时间短,反应温度低于点火温度,不足以支撑燃烧反应进行;当粉尘质量流量大于空气质量流量10倍时,氧气含量过低,同样不足以支撑燃烧反应进行。空气湿度越大,燃烧反应最高温度越低,燃烧反应平均温度会出现先增后降的现象。研究结果可为工业生产、抛光、打磨等工序中的防燃、防爆问题提供参考依据及基础理论。
In this paper,a modified Hartmann tube was used for the determination of the non-premixed combustion characteristics of magnesium aluminum alloy dust,and Fluent software was used for simulation to research the fire properties under different conditions.The effects of particle size,air mass flow,dust mass flow,and air humidity on the combustion reaction temperature of magnesium aluminum alloy dust were discussed by using the PDF model.The experimental and simulation result indicated that the average combustion reaction temperature of magnesium aluminum alloy dust with particle sizes of 80μm,120μm,150μm,and 270μm are 2349.8K,2253.7 K,2167.3 K,and 2094.7 K.With the same dust mass flow,the bigger particle is,the smaller the contact area and combustion temperature between dust and air are.Magnesium aluminum alloy dust combustion is divided into oxygen-rich and oxygen-poor combustion.The critical mass flow point of oxygen-rich and oxygen-poor combustion of magnesium aluminum alloy dust is 45.54%.The contact time between oxygen and magnesium aluminum alloy dust decreases with the increase of its flow ratio.When the mass flow of air and dust is greater than 10:1,the reaction temperature is lower than the ignition temperature,which is not enough to support the combustion reaction.However,when the ratio of dust to airflow is greater than 10:1,the oxygen content is too low to support the combustion reaction.In addition,the maximum combustion temperature was reduced with increasing humidity.However,the average temperature of the combustion reaction increases first and then decreases.The research results can provide a scientific and effective reference basis and basic theory for the fire prevention and explosion-proof problems in Polishing and grinding processes.
作者
巨建鹏
胡凌艳
董国强
王焘
侯蕊
JU Jianpeng;HU Lingyan;DONG Guoqiang;WANG Tao;HOU Rui(Institute of Ordnance Industry Health,Xi'an 710065,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2023年第7期2288-2295,共8页
Journal of Safety and Environment
关键词
安全工程
镁铝合金粉尘
燃烧试验
Fluent仿真
safety engineering
magnesium aluminum alloy dust
combustion test
Fluent simulation
