Research And Design Of Compact Horizontal Wet Electrostatic Precipitator

At present,in response to the increasingly severe atmospheric environment,the State has issued a number of environmental policies and promulgated new air pollutant discharge standards to further reduce emission of flue gas particulate matter and other pollutants in thermal power plants.Domestic coal-fired power plants began to upgrade or retrofit existing emission control equipment to meet the new standards.Among different transformation and upgrading measures,installation of WESP(Wet Electrostatic Precipitator)between wet FGD and chimneys,outstands due to short installation period,lower overall cost,good reliability and its capability to remove various pollutants,which is favored by major coal-fired power plant owners,thus becoming the mainstream solution.At the same time,the compact arrangement of existing emission control equipment(DeNOx,De-dusting equipment&FGD etc)brings much difficulty to erect new equipment.lt is of great application value and academic significance to study compact horizontal wet electrostatic precipitator which adapts to the existing site conditions and simultaneously remove fine dust with high efficiency.Aiming at the two goals of "space saving" and "reduce emission at high efficiency",intensive study has been done on WESP's key technology based on its existing technology and,with the help of modern computer simulation technology and advanced lab equipment.On the basis of the traditional dry-type ESP(electrostatic precipitator),the collection electrode system is divided into two parts,and double structure is arranged in the upper and lower casing of the horizontal WESP to lower land area requirement.An improvement is made on the hanging sub-system of emitting system of the conventional horizontal WESP that adopts side hanging structure.The new hanging sub-system is arranged on the top of the dust collecting plate to make the structure more compact and economical space,while at the same time not only meeting the strength requirements,but also ensuring effective discharge space.CFD(Computational Fluid Dynamics)digital simulation technology is applied to study the flow characteristics of the flue gas in the duct before the WESP and the inlet nozzle of the double-layer WESP to determine proper arrangement of guide vanes and distribution plates,preventing the flue gas cross airflow and ensuring even flue gas distribution to achieve the optimal dust removal efficiency.At the end of this paper,the aforementioned research results of double-layer horizontal WESP is applied to specific industrial projects,to verify its practicality and reliability,laying the foundation for its subsequent improvement and development,as well as large-scale promotion and application.