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简要介绍了含氧气和水蒸气环境下硼颗粒点火动力学模型和燃烧动力学模型,并给出了详细的数值求解方法,采用权威实验数据校验模型的合理性和准确性。利用模型预测硼颗粒点火燃烧特性,分析表面氧化层厚度,粒径,环境压强,氧分压,水蒸气分压及环境温度等因素对硼的点火燃烧特性的影响,并与相应的实验结果进行比较。结果显示,硼颗粒点火时间和燃烧时间均随粒径增大而增加。当粒径小于20μm时,燃烧时间与粒径基本呈正比关系。而当粒径大于20μm时,燃烧时间随粒径增大呈二次方增长。点火时间随初始氧化层厚度增加单调递增,增长率达到65ms/μm。点火时间和燃烧时间随环境压强增大基本呈现减小的趋势,但3MPa以上均不敏感。氧分压的提高对点火时间没有影响,但使燃烧时间明显减小,而水蒸气分压的升高则显著降低点火时间,但对燃烧时间几乎没有影响。环境温度的升高会减小点火时间,但对燃烧时间的影响可忽略。
The ignition kinetic model and combustion kinetic model of boron particles containing oxygen and steam are briefly introduced. A detailed numerical solution method is given. The author verifies the rationality and accuracy of the model by authoritative experimental data. The model was used to predict the ignition and combustion characteristics of boron particles. The effects of surface oxide thickness, particle size, ambient pressure, partial pressure of oxygen, partial pressure of water vapor and ambient temperature on the ignition and combustion characteristics of boron were analyzed. The results were compared with the corresponding experimental results Compare The results show that the ignition time and burning time of boron particles increase with the increase of particle size. When the particle size is less than 20μm, the burning time and the particle size is basically proportional relationship. When the particle size is more than 20μm, the combustion time increases quadratically with the particle size increasing. The ignition time increases monotonically with the initial oxide thickness increasing by 65 ms / μm. Ignition time and combustion time with the ambient pressure increases basically showed a decreasing trend, but 3MPa are not sensitive. The increase of oxygen partial pressure has no effect on the ignition time, but the combustion time is significantly reduced. The increase of partial pressure of water vapor significantly reduces the ignition time, but has little effect on the combustion time. The increase of ambient temperature will reduce the ignition time, but the impact on the combustion time is negligible.