火电厂燃煤粉尘在交流电场中凝并与脱除的实验研究

发布时间：2018-05-12 06:51

本文选题：燃煤电厂 + 交流电场　；参考：《上海电力学院》2014年硕士论文

【摘要】：微细粉尘严重危害人类健康和大气环境，现阶段燃煤电厂常用除尘技术对粉尘整体脱除效率较高，然而对1μm以下粒径的粉尘粒子捕集能力较弱，电凝并作为一种粉尘预处理系统能有效的提高除尘器对微细粉尘的捕集效率。针对以上情况，本文研究了交流电压条件下对粉尘荷电凝并及脱除效率的影响因素，并对600MW燃煤电厂粉尘排放特性及交流电压下燃煤粉尘凝并脱除效率进行了较为深入的探讨，取得了以下成果： 1.介质阻挡放电器（DBD）将粉尘荷电凝并过程合二为一，其优点在于能使粉尘粒子在放电器中反复进行荷电凝并，有利于提高凝并效率。在放电器后部加装PPS（聚苯硫醚）过滤除尘器，在提高微细粉尘脱除效率的同时，缩短了除尘装置的总长度，降低了成本。 2.通过改变影响粉尘粒子荷电凝并的条件，实验得出粉尘凝并效率随电压的升高而提高，最佳凝并频率为120Hz，延长粉尘荷电凝并时间能有效的提高凝并效率。同时，粉尘性质对凝并效率也有着一定的影响，粉尘介电常数越大，荷电能力越强，凝并效果越好。 3.通过实验得出PPS滤料存在最佳过滤风速，为1.5m/s，粉尘脱除效率随荷电凝并电压升高而提高。粉尘性质影响除尘效率，粉尘比电阻越小，，除尘效率越高，相对湿度在一定范围内越大，除尘效率相对较好。0.5μm的粉尘荷电凝并前后较粒径为10μm粉尘脱除效率变化明显，这说明静电凝并-纤维脱除是一种有效的控制微细粉尘排放的方式。 4.600MW燃煤机组粉尘经静电除尘后以PM2.5为主，实验中所使用的静电凝并-纤维过滤除尘技术是一种针对燃煤电厂粉尘的有效控制方法，在布袋除尘器前加装电凝并装置，调节过滤风速1.5m/s，凝并电场频率120Hz，荷电凝并电压12kV，此时，除尘后0.3-0.5μm、0.5-1μm级别的粉尘粒子个数较无凝并条件下分别减小了14.1%和8.2%。这说明，电凝并能有效提高PPS滤料对燃煤电厂微细粉尘的脱除效率。
[Abstract]:Fine dust is a serious hazard to human health and atmospheric environment. At present, the dust removal technology used in coal-fired power plants is relatively high in overall dust removal efficiency, but the ability to capture dust particles with particle size less than 1 渭 m is relatively weak. As a dust pretreatment system, electrocoagulation can effectively improve the collecting efficiency of dust precipitator. In view of the above situation, this paper studies the factors that affect the efficiency of charged condensation and removal of dust under the condition of AC voltage, and probes into the dust emission characteristics of 600MW coal-fired power plant and the efficiency of coagulation and removal of coal-fired dust under AC voltage. The following results were achieved: 1. The dielectric barrier discharger (DBD) combines the charge condensation process of dust into one, and its advantage lies in the fact that the dust particles can be charged and condensed repeatedly in the discharger, which is helpful to improve the coagulation efficiency. The application of PPS (polyphenylene sulfide) filter in the rear of the discharge apparatus can improve the removal efficiency of fine dust at the same time shorten the total length of the dedusting device and reduce the cost. 2. By changing the conditions that affect the charged coagulation of dust particles, the experimental results show that the efficiency of dust coagulation increases with the increase of voltage, and the optimum coagulation frequency is 120 Hz, and prolonging the time of charged coagulation of dust particles can effectively improve the coagulation efficiency. At the same time, the properties of dust have a certain influence on the coagulation efficiency. The higher the dielectric constant of dust, the stronger the charge capacity and the better the coagulation effect. 3. The results show that the optimal filtration speed of PPS filter media is 1.5 m / s, and the dust removal efficiency increases with the increase of charged coagulation and voltage. The dust property affects the dust removal efficiency. The smaller the dust specific resistance, the higher the dust removal efficiency, the greater the relative humidity in a certain range, the better the dust removal efficiency is, the better the dust collection efficiency is, the better the dust removal efficiency is before and after the dust collection is 10 渭 m in particle size. This shows that electrostatic coagulation-fiber removal is an effective way to control the emission of fine dust. The dust of 4.600MW coal-fired unit is mainly controlled by PM2.5 after electrostatic dusting. The electrostatic coagulation-fiber filter dust removal technology used in the experiment is an effective control method for dust in coal-fired power plant, and the electric coagulation unit is installed in front of the bag dust collector. Adjusting filtering speed 1.5 m / s, coagulation and electric field frequency 120 Hz, charge-coagulation voltage 12 kV, at this time, the number of dust particles of 0.3-0.5 渭 m or 0.5 渭 m after dust removal is decreased by 14.1wt% and 8.2%, respectively, compared with those without coagulation. This shows that electrocoagulation can effectively improve the removal efficiency of fine dust from coal-fired power plants by PPS filter media.
【学位授予单位】：上海电力学院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X773

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