Assessment of the Effect of Voltage Distortion on the Operation of the Main Elements of a Electric Arc Plasma Thermochemical Fuel Treatment Systems

Abstract

The work is devoted to the study of the influence of the electric energy quality on the service life of electrodes of a plasma thermochemical fuel treatment systems used in thermal power plants running on coal fuel. The issues of moving the near-electrode plasma section using magnetic-wave scanning are discussed in detail. The purpose of the work is to study and evaluate the effect of voltage distortion on the trajectory of the near-electrode plasma section with magnetic-wave scanning and subsequent changes in the service life of the plasmatron under certain operating conditions. The ANSYS Maxwell software was used as the main research tool. The computer simulation was performed with the following main experimental parameters: the coefficient of asymmetry in the zero sequence (K_0U) is 2% and 4%; the coefficient of asymmetry in the negative sequence (K_2U) is 2% and 4%; the voltage deviation δU₍₊₎ is 5% and 10%; the materials used for manufacturing electrodes: copper (Cu), a pseudo-alloy of tungsten, nickel and copper (W + Ni + Cu), and a pseudo-alloy of molybdenum, tungsten, and copper (Mo + W + Cu). Based on the obtained simulation results, graphical representations of changes in the trajectories of the near-electrode plasma section under various distorting factors, dependences of changes in the values of specific erosion of various electrode materials, and graphical dependences of changes in the service life of electrodes of plasma systems are constructed. The studies performed using computer modeling based on the ANSYS Maxwell software product has made it possible to quantify the effect of voltage distortions on the trajectory of the near-electrode plasma section and, consequently, the service life of the plasmatron electrodes. In particular, in the course of the study, a detailed assessment and analysis of the degree of influence of the following indicators of electrical energy quality was performed: the coefficients of asymmetry in the negative and zero sequence and voltage deviations on the operation and technical condition of the electrodes of plasma systems. The results of the study are discussed, and recommendations are formulated for the plasma thermochemical fuel preparation systems used at thermal power plants to ignite the fuel of pulverized coal boilers.