| Wire-plate electrostatic precipitator (ESP) has extensive application in the coal-fired power plants, and dust removal process is the key to solve this problem. However, existing studies always focus on a single wire-plate unit and ignore the influence of entire structure on dust removal process. The results can’t guide the practice effectively. The model is based on a very complex interaction mechanisms between fluid mechanics, particle dynamics and static electricity and Eulerian method and Lagrangian method is used to write UDF program. Considering the complicated structure, dust removal process is integrated into the entire ESP. Theoretical research and numerical simulation are used to investigate electric field distribution, particle charging and moving process. Simultaneously, the influence of geometric structure, operating parameters and particle characteristics on dust collecting efficiency are analyzed by using numerical simulation.Through the study of electrostatic precipitator, it can be seen that as the cathode wire number and the plate length increases, the collection efficiency increases, on the contrary, as the wire-to-plate spacing increases, the collection efficiency decreases. The best dimensions of single wire-plate unit in this paper are proposed as follows:the cathode wire number is 3, the wire-to-wire spacing is 0.2m, the wire-to-plate spacing is 0.1m and the plate length is 0.8m.Further more, particle distribution and the influence of voltage, gas velocity, concentration on dust collecting efficiency were studied either. In the middle of the ESP, the dust collecting efficiency is higher, but near the edge of the ESP, the dust collecting efficiency is lower. Low inlet velocity, high applied voltage and large particle diameter are beneficial to improving the dust collecting efficiency. When the particle concentration at lower levels, higher concentration lead to higher dust collecting efficiency. As particle concentration increase, when it achieve a level that beyond a dust collecting limit under a certain applied voltage, dust collecting efficiency began to reduce. When the gas and particle velocity is higher, the particle diameter and concentration is lager, turbulent situation is more severe and trajectory is less stable. |
