基于电弧辐射模型的焊接热过程测温分析

Analysis of temperature measurement based on the model of arc radiation in welding thermal process

基于Saha方程计算电弧等离子体粒子密度,根据Kramers-Uns ld理论得到电弧等离子体辐射强度公式。根据测温系统几何分布情况,建立电弧辐射模型,得到电弧干扰对测温的信噪比公式。利用此公式从测温仪的角度、波长和电弧有效温度三方面对近弧区弧光对测温点的干扰进行了分析,从理论上定量地证明了在小电流电弧干扰时辐射测温法的可行性。为了验证这一理论,分别在电流峰值、基值和瞬时熄灭电弧这三个时刻采集温度,并对这三个时刻的温度变化趋势进行比较。结果表明,理论上提出的小电流时刻采用辐射测温方法是可行的。

Base on Saha equation,the arc plasma particles' density is obtained,and then according to the theory of Kramers-Unsld,the radiation intensity of arc is obtained.In order to get the model of arc radiation,the location of temperature measurement has been built.The ratio of signal to noise is used to analyze the effect of arc on radiation thermometry which the three factors of the angle of temperature detector,wavelength and the arc effective temperature are considered.Theoretically,the method of temperature measurement is feasible when the arc current is decreased to a smaller value in welding process.Experiment has been done;temperature data of three times which are peak value of arc current,least value of arc current and time of cutting arc current instantaneous have been collected.The experiment results show that the method of temperature measurement is feasible.