硼粉燃烧效率的影响因素研究

Study on influencing factors of combustion efficiencyof boron powder

为了提高B粉在氧弹中的燃烧效率,从而准确测得B粉的实际燃烧放热量,以便对不同来源的B粉进行质量评估,进而为含B富燃料推进剂的配方设计及能量预估提供依据。建立了一种能使硼粉充分燃烧并测得其放热量的方法,以双铅-2推进剂(SQ-2)作助燃剂,丙酮作溶剂,采取干法与湿法相结合的方式制备样品,利用恒温式氧弹量热仪测试样品燃烧放热量,并计算B粉燃烧效率,采用Fluent软件对B粉燃烧过程中的氧弹内流场进行数值模拟,分析氧弹内温度及氧气浓度随时间的分布,研究了SQ-2与B粉的混合质量比、充氧压强、坩埚位置、坩埚大小及有无挡板对B粉燃烧效率的影响。结果表明,SQ-2与B粉的最佳混合质量比为10∶1;最佳充氧压强为3 MPa;选择内径大(最佳内径17 mm)、高度低(最佳高度5 mm)的坩埚,并减小坩埚与氧弹底部的距离(最佳距离10 mm),同时选用不含挡板的坩埚支架,可为B粉创造良好的燃烧环境,在氧弹中的最大燃烧效率可达99.36%。

In order to improve the combustion efficiency of B powder in the oxygen bomb,the actual combustion heat release of B powder is accurately measured so that the quality of B powder from different sources can be evaluated,then providing evidence for the formula design and energy estimation of the B-containing fuel-rich propellant.A method for fully combusting B powder and measuring its heat release was established.The samples were prepared by combining dry and wet method using SQ-2 as combustion-supporting agent and acetone as solvent,then the combustion heat release of the samples was measured by constant temperature oxygen bomb calorimeter;the combustion efficiency of B powder was calculated,and the internal flow field in the oxygen bomb during the combustion of B powder was numerically simulated by means of Fluent software;the distribution of temperature and oxygen concentration in the oxygen bomb with time was analyzed,and the effects of the mixing mass ratios of SQ-2 and B powder,oxygenation pressure,crucible position,crucible size,and crucible with or without flame shield on the combustion efficiency of B powder were studied.The results show that the best mixing mass ratios of SQ-2 and B powder is 10∶1;the best oxygenation pressure is 3MPa;selecting a suitable crucible with a large inner diameter(the best inner diameter is 17 mm)and a low height(the best height is 5 mm)and reducing the distance between the crucible and the bottom of the oxygen bomb(the best distance is 10mm)as well as selecting the crucible support without flame shield can create a good combustion environment for B powder,and the maximum combustion efficiency in the oxygen bomb can reach 99.36%.