【作者】 刘小伟；

【导师】 杨仕友；

【作者基本信息】 浙江大学 ， 电气工程， 2012， 硕士

【摘要】 电弧等离子体因具有高温、能量密度大、环保等优点,在工程中具有广阔的应用前景。但其不足之处是横截面积小,加热面积小且温度不均匀。因此,基于电弧具有良好的导电性,工业上利用外加轴向磁场驱动电弧旋转是一种获得大面积均匀电弧的实用手段。在电弧旋转过程中,高温电弧对电极很强的烧蚀作用,而电极的烧损会影响到等离子体发生器的寿命。磁旋转发生器中电弧旋转速度作为影响电极传热的关键因素,是该类技术或产品的重要指标。因此,对电弧旋转速度的研究具备重要的理论意义和工程价值。本文研究了同轴等离子体发生器电弧运动轨迹和旋转速度的数值计算方法。根据电弧的通道模型,计算了电弧的弧柱半径。基于电极产生的电场分布,研究了电弧等离子体的运动轨迹,最后采用电弧的刚体模型分析电弧的旋转运动,根据电弧稳态旋转时电磁力矩和流体阻力力矩相平衡条件,建立了电弧稳态旋转的数学模型,然后采用禁忌搜索算法计算电弧稳态旋转速度。数值计算结果表明粒子的空间运行轨迹为近似平面的抛物线以阴极为对称轴旋转形成的空间迹线。此外,实验结果证明了理论工作的有效性和正确性,为工程分析和设计提供了理论依据。更多还原

【Abstract】 Thermal arc plasma has broad applications due to its advantages, such as high temperature, high energy density, environmental protection, etc. However, the disadvantages associated with the thermal arc plasma are thoses that its heating area is small and the temperature is nonuniform as the result of the small cross-sectional area. Applying external axial magnetic field to drive the arc plasma to rotate is a very practical way of obtaining uniform high-temperature conditions of larger area based on the good conductivity of the arc in industry applications. The high-temperature arc has an ablative effect on the electrode while rotating. And the erosion of the electrode affects the longevity of plasma generator. As the key factor of the heat-transfer process of an electrode, the revolution speed of arc is an important technical specification of such techniques. For this reason, the study of the revolution speed of arc is of important theoretical significance and engineering value.This paper proposed a numerical model and method to calculate the revolution locus and speed of arcs inside a coaxial plasma generator. The radius of the arc was decided according to channel model. The revolution locus of plasma arc was studied based on the electric-field distribution generated by the electrode. The revolution speed of the arc was determined form the mathematical model based on the balance of damping and driving electromagnetic torques of a rigid body using a tabu search algorithm.Numerical results have demonstrated that the trajectory of the plasma arcs in 3D is formed by the rotation of a 2-D parabola locus. Also, the proposed work is validated by the primary tested results and this provides the theory for engineering analysis.更多还原