直流电弧等离子体炬的能量特性实验分析

Experimental analysis on energy characteristics of DC arc plasma torch

通过实验分别获得空气和氮气作为工作气体下自稳弧长型直流电弧等离子体炬的能量特性数据,得出弧电流、气量与弧电压之间的影响规律和函数关系,进而分析等离子体射流功率与比焓的变化特征。结果表明:弧电流恒定不变的情况下,弧电压及功率随气量的增大而增大,比焓随气量的增大而减小;气量恒定不变的情况下,功率及比焓随弧电流的增大而增大,弧电压随弧电流的增大而减小;拟合伏安特性函数式,空气为U_(air)=480(I^(2)/G)^(-0.08)G^(0.30),氮气为U_(N2)=693(I^(2)/G)^(-0.09)G^(0.25),两者的伏安特性曲线总体趋势相同,且在相同弧电流与气量下,氮气作为工作气的弧电压、功率及比焓均比空气大。

The energy characteristic data of self-stabilized DC arc plasma torch with air and nitrogen as working gas are obtained by experiment.The influence pattern and function relation between arc current,gas volume and arc voltage are concluded,and the variation characteristics of plasma jet power and specific enthalpy are analyzed.The results show that when the arc current is constant,the arc voltage and power increase with the increase of gas volume,while the specific enthalpy decreases with the increase of gas volume.When the gas volume is constant,the power and specific enthalpy increase with the increase of arc current,and the arc voltage decreases with the increase of arc current.By fitting the volt-ampere characteristic function,U_(air)=480(I^(2)/G)^(-0.08)G^(0.30) for air and U_(N2)=693(I^(2)/G)^(-0.09)G^(0.25) for nitrogen,the volt-ampere characteristic curves of the two will have the same general trend.Under the same arc current and gas volume,the arc voltage,power and specific enthalpy of nitrogen as the working gas are larger than that of air.