Measurement of Specific Enthalpy Under Very Low Pressure Plasma Spray Condition

摘要

VLPPS has attracted much attention in recent years, especially concerning its potential applications but not so much concerning the properties of the plasma jet. Operating parameters such as the chamber pressure and the secondary gas flow rate have a strong influence on specific enthalpy and temperature of the plasma jet, and then on the efficient use of the system. In this work, thermodynamic properties measurements under very low pressure (i.e., around 1 mbar) were performed using a modified enthalpy probe (increase of the internal diameter and thermal insulation of the head). Several parameters such as arc current intensity, hydrogen gas flow rate and working distance were considered in order to check their effect on the characteristics of the plasma jet and to determine the variation of the specific enthalpy, temperature, and heat flux versus these parameters.