Analysis For Space Electric Characteristics In ESPs

Our country has the biggest quantity of coal production and consumption in the world. Serious air contamination will be brought if the coal dust can't be treated efficiently. About 90% ESPs are used for collecting ash dust in coal-fired power boilers in our country. With the increasingly attention in environment protection, the performance of ESPs must be improved to reduce emission concentration of dust.The electric field of ESP determines corona generation, particle charging and particle collection, which is the main factor of running performance of ESP. Because of the proceeding of corona discharge is nonlinear, the analysis solution can hard be obtained. So the numeric method is depended in solve the question.At present, simulation and theory study of electric field caused by corona discharge are mainly concentrating on simple 2-D model, which strictly obeys 3-D distribution because the corona discharge is a process of space discharge.This paper uses Poisson equation and Current Continuity equation as the controlling equation. The MATLAB software is used to program so as to solve the coupling equations. The simulation of electric field in wire-tube and wire-plate ESPs, and its outcome is compare to theory and experiment data to validate the reliability of numerical method in the paper. Moreover, the numerical method in this paper is applied to compute the electric field in barb-plate ESP, and gained the distribution of electric potential, space charge density, electric field intensity and electric current density in 3-D space, which offers a more exacter method for the numerical analysis and theory study on ESP.Meanwhile the influence of different inter-electrodes space, discharge space, corona radius and ion mobility to electric characteristic is simulated to offer theory for systemic analysis.