Research On Optimization Efficiency Of Electrical Precipitator For Power Plant

Electric precipitator is the major equipment which uses in the modern industry of removing dust, with the issuing of GB13223-2011 "emission standards of air pollutants for thermal power plants", which increases pressure on coal-fired power plants for pollutants emission reduction. At present, a lot of electric precipitators can not meet the emission concentration standard, and the emission concentration changes with the coal quality at the same time, so, there is a serious problem for a lot of electric precipitators. At present, main issues of ESP in our country exist in the following aspects:(1) the severe secondary dust caused by vibration;(2) the internal structure of ESP is not reasonable enough, leading to uneven gas flow;(3) polar matching form is not the best;(4) the collecting effect of fine dust is poor.In view of the above problems, this paper takes a power plant in key area as the prototype which was lower than the design efficiency to optimize this electric precipitator. Firstly, the fly ashes at the exit of inlet and outlet of No.2 ESP and outlet of No.2 FGD in this power plant were sampled. Samples were detected and analyzed by scanning electron microscope(SEM), X-ray energy dispersive spectroscopy(EDS),X-ray diffraction(XRD) and Mastersizer2000 laser particle size analyzer in order to investigate the microstructure, elemental composition, particle size distribution and other physicochemical properties, and explore the reasons which cause the low efficiency. Secondly, based on the experiments results research, optimal selection is conducted to the main parameters in the overall design, such as the plate spacing,influence factors of current density distribution, wire spacing, the type of corona wire and so on. Improvement program has been presented, which provides certain experiences for the design and operation of electrostatic precipitators. Air-distribution is one of the main factors affecting the efficiency of ESP, this paper adjusts the number of guiding plates and air flow uniform plates to change flow-pattern. By using the FLUENT software to simulate airflow distribution in electrostatic precipitator with three-dimensional model. Simulated results show that: when using double guide plates, three air distribution plates, the air distribution plate opening rates of 40%,35% and 30% respectively, the air flow pattern is ideal. Remove dust on the surface of electrode in a timely and effective manner, to prevent the secondary dust, is the important condition to ensure the efficient operation of electrostatic precipitators. This paper analyses several problems related to the electrode shaking of ESP, such as: the distribution of shaking force, shaking type, vibrating acceleration, vibrating strike hammer, etc. Analyzes the influence factors of vibrating acceleration value, and the vibrating characteristics of lateral rotary hammer adopted in cathode and anode are summarized. A brief introduction and comments on the bottom, top and combining rapping technology of ESP are described. Results are used in the actual transform for electric precipitator, and obtain a good effect, which has certain practical significance.