Quasi-static and dynamical computation of V-I characteristics of adust-loaded pulse-energized electrostatic precipitator

This paper describes an accurate model and a new procedure for the numerical computation of the electric field, current and charge density, in a pulse energized electrostatic duct-type precipitator, in presence of dust. The proposed model is compared to the classical steady-state model used in the past. The old model shows nonphysical bumps and discontinuity whereas the new approach predicts the natural transient behavior of electrical quantities. The partial differential equations governing the transient phenomena are solved by means of an implicit-explicit finite-difference time-domain method, which ensures a fast computation. The obtained results, compared with experimental values, show a good accuracy of the presented method     

125 MW机组电除尘器的技术改造

介绍了株洲华银火力发电有限公司2台125MW机组电除尘器增效改造的方法和取得的良好效果,为在不动土建的情况下,将电厂电除尘器三电场改为四电场提供了参考经验。     

Automatic control and management of electrostatic precipitator

The efficient operation of an electrostatic precipitator (ESP) in practice depends upon many variables, such as charging method, particle size, gas flow, temperature, dust resistivity, etc. With air pollution control requirements becoming increasingly stringent, it is essential to closely monitor and accurately control the key parameters of an ESP control system. The efficient functioning of an ESP normally means minimizing power consumption and maximizing dust collection. Several control strategies can be adopted to meet this broad requirement. In this paper, a distributed control technique of an ESP, which uses the actual dust emission and boiler load as feedback inputs has been explained. The electrostatic precipitator management system, which is a system designed by Bharat Heavy Electricals Ltd., Hyderabad, India, to meet the above control strategies using the distributed architecture to achieve efficient ESP operation is also described     

浅析电除尘器的振打清灰方式

对顶部电磁振打电除尘器与侧部挠臂锤振打电除尘器在振打机理、运行可靠性、维护性能、成本等方面进行比较分析，认为电除尘器的顶部振打清灰方式值得选取。     

Pulse energization system of electrostatic precipitator forretrofitting application

A pulser module has been developed for electrostatic precipitators for upgrading the performance of existing plants. The module is inserted between the existing DC power supply and corona electrodes. A sawtooth voltage appears on the corona electrodes at a switching frequency, including at its leading edge a transient LC oscillation with a very sharp first peak and fast-decaying amplitude. This acts as the submicrosecond pulse energization, producing very active negative streamers in uniform distribution along the entire length of corona wires of the conventional construction. The average of the sawtooth voltage produces a DC field between the corona and the collecting electrodes. This direct-coupled pulse energization indicates in present laboratory tests exactly the same collection performance as the hitherto most effective submicrosecond pulse energization using a coupling capacitor and a DC bias voltage. A specific feature of the present pulse energization system is its simplicity in construction and low initial and operating costs     

Finite element method investigation of electrostatic precipitator performance

This paper aims at analysis of the monopolar ionized field in electrostatic precipitator. A numerical model for simulating precipitation of particles in electrostatic precipitator is discussed in this paper. It includes all essential phenomena affecting the process. An iterative finite‐element technique is used to solve Poison's equation. We proposed the introduction of a potential corresponding to the critical minimum ionization field directly in the finite element formulation as a Dirichlet condition. The theoretical migration velocity is obtained by balancing the drag force with the Coulomb force or electrostatic force acting on a particle. We used the model introduced by Cochet for predicting a particle charge. The model assumes that a particle of the same size attains an equivalent maximum amount of charge for a charging time equal to infinity. Particles influence the electrical field, flow field, electrical migration velocity, gas discharge, particle charge and collection efficiency. Copyright © 2014 John Wiley & Sons, Ltd.     

影响静电除尘器效率的控制因素

通过研究影响静电除尘器除尘效率的几个常见可控因素，分析漏风、比电阻、振打周期及电场闪络频率对除尘效率的影响，并提出相应解决措施，使静电除尘器保持更高的除尘效率。     

静电除尘器供电控制方式探讨

本文通过对静电除尘器在“火花跟踪”和“间歇供电”方式下除尘效率及电耗的比较 ,认为应重视静电除尘器供电方式的选择。在粉尘比电阻较高时 ,选用“间歇供电”方式不仅能提高除尘效率 ,还可大幅降低电场电耗。     

电除尘器电源控制系统的改造

通过对宁夏石嘴山发电有限责任公司电除尘器除尘效果不佳的原因分析,提出了较为合理的改造方案。实践证明:经过改造后的电除尘器,提高了除尘效率,降低了出口烟尘排放浓度,同时减少了电能损耗与振打次数,取得了一定的社会与环保效益。     

DCM工作模态下LCC静电除尘变压器仿真设计

通过在Saber中搭建LCC谐振电路,在固定开关频率和占空比下,根据输出功率,分析了高频变压器的原边电流、电压和视在功率。结合传统AP法,计算出合适的绕制参数和磁芯尺寸。利用Maxwell软件,在3D瞬态场下,分析变压器原副边的耦合系数,确定合适副边对原边的漏感值。再利用Saber中自带的磁元件工具箱,在2D环境下分析绕组分布和层间电容值。仿真结果最终得到符合谐振要求的寄生参数。仿真设计有助于在实际制作变压器之前,对绕制参数及工艺提供可靠指导。     

Three-dimensional ionic wind and electrohydrodynamics of tuft/point corona electrostatic precipitator

The two-dimensional flow interaction between the primary flow and the secondary flow (often called an electric wind or ionic wind) in the wire-duct electrostatic precipitator (ESP) has been investigated theoretically and experimentally in the past. However, the analysis was limited to the two-dimensional, which is acceptable only for the positive polarity and small tuft spacing. The negative corona, commonly used for the industrial ESPs, generates tufts along the corona wire and the point coronas on the discharge wire and requires three-dimensional analysis. Three-dimensional electric field and space-charge density distributions, and the flow interaction between the primary flow and secondary flow, i.e., electrohydrodynamics were investigated. The computational results show that the secondary flow distribution consists of a donut-shaped ring from each tuft or corona point, which was predicted by the first author 16 years ago. When the primary flow exists, a pair of spiral rings, like Goertler vortices, is formed in the direction of the primary flow. The flow interaction was described using dimensionless number N/sub EHD/, which is the ratio of the ionic wind velocity to the primary flow velocity. The effects of particle motion in the electrohydrodynamic field in the tuft/point corona ESPs are discussed.     

电除尘器效率降低原因分析及对策

针对新余发电有限责任公司电除尘器除尘效率下降的情况,分析其存在的主要问题,简要介绍所采取的改造措施:将相应的电除尘器一电场阴极线更换为管型芒刺线;阳极板下部加装加强板;阴极振打轴承改为托滚式轴承等。改造实施后电除尘器除尘效果明显改善,可靠性得到提高。本电除尘器的改造经验对其他电厂解决同类问题具有一定借鉴意义。     

Simulation of corona in wire-duct electrostatic precipitator bymeans of the boundary element method

A new approach for modelling the space density and the electric field distribution in electrostatic precipitators is presented in this paper. Two numerical techniques are used iteratively until a self-consistent solution is obtained: the boundary element method, for evaluation of the electric potential; and the characteristic method, determining the charge distribution. This hybrid approach is applied to simulate the electrical conditions in a wire-duct electrostatic precipitator and obtained results are compared with the experimental data     

超超临界1000MW燃煤机组干式电除尘器特性分析

电除尘器出口烟尘质量浓度反馈控制可以降低电除尘器的高能耗,出口烟尘质量浓度动态模型是实现电除尘器质量浓度反馈控制的基础。本文研究了超超临界1 000 MW机组五电场结构干式电除尘器静态特性和动态特性。首先对前三电场进行静态特性试验,在此基础上以电除尘器末级两电场高频电源的二次电流为输入,出口烟尘质量浓度为输出,在4个典型负荷点做二次电流的阶跃扰动试验,根据试验数据,采用免疫遗传算法拟合出口烟尘质量浓度传递函数动态模型,并将模型结果与实际测量结果对比。结果表明,建立的动态模型可以反应电除尘器的真实特性,具有较高的精度。     

电除尘高压供电控制稳定性分析

高压供电质量是影响电除尘器性能的最关键因素,通过分析,提出了消除高压供电装置不稳定因素的措施。使电除尘器长期保持安全、稳定、高效运行。     

Numerical modeling of near corona wire electrohydrodynamic flow in a wire-plate electrostatic precipitator

Numerical modelling of the flow velocity fields for the near corona wire electrohydrodynamic (EHD) flow was conducted. Solutions of the steady, two-dimensional momentum equations have been computed for a wire-plate type electrostatic precipitator (ESP). The equations were solved in the conservative finite-difference form on a fine uniform rectilinear grid of sufficient resolution to accurately capture the momentum boundary layers. The numerical procedure for the differential equations was used by SIMPLEST algorithm. The CFD code coupled with Poisson's electric field, ion transport equations and the momentum equation with electric body force, was used for the numerical simulation with the Chen-Kim k-epsiv turbulent model. The numerical results show that EHD secondary flow was clearly visible in the downstream regions of the corona wire despite the low Reynolds number for the electrode (Re _cw=12.4). Secondary flow vortices caused by the EHD increases with increasing discharge current or EHD number, hence pressure drop of ESP increases     

电除尘器电场的工作特性分析在生产实际中的应用

针对哈三电厂电除尘器在实际运行中存在的问题,应用电除尘器工作特性分析方法,能较快的查找原因,解决实际问题,减少检修盲目性,提高设备的完好率,从而提高了电除尘器的效率。     

静电除尘器用恒压源与恒流源中试试验研究

高压电源是静电除尘器的核心部件,本文通过在芒刺线单室湿式静电除尘器试验平台下开展中试试验,采用静电低压撞击器（ELPI）实时在线测量不同粒径颗粒物的荷电量及其浓度分布,对比研究了当前静电除尘器使用的单相恒压源和单相恒流源2种供电形式的除尘效率、颗粒物荷电特性、伏安特性、功耗等试验指标。试验结果表明:在不发生过量的火花击穿前提下恒压源相比于恒流源具有更高的平均运行电压和更高的电晕电流,恒压源和恒流源最高平均电压分别为70 kV和55 kV,电晕电流分别为7.12 mA和6.00 mA,所对应的最大除尘效率分别为85.9%和84.2%;在相同除尘效率下恒压源相比于恒流源节能20%,因此恒压源比恒流源更具有技术和经济优势。相关结论对静电除尘器改造升级具有一定的参考价值。     

大型燃煤锅炉电除尘器投运方式探讨

北仑发电厂通过对600MW燃煤锅炉煤油混烧阶段投运电除尘器的不利影响和可行性进行分析，经现场试验和实际应用，实现了锅炉投煤粉后电除尘器的全程投运，大幅度地减少了烟尘排放量。     

哈三电厂电除尘器存在的问题及改造

通过对哈三电厂电除尘器几年来所出现的各种问题逐一进行分析,采取了相应的解决措施,并对电除尘器进行了改造。改造后,提高了电除尘器除尘效率,降低了粉尘排放量,粉尘排放指标符合国家规定的排放标准,极大地改善了哈三电厂生产和周围生态环境。