【摘要】：飛灰顆粒荷電是其被電除塵器捕集的前提和基本過程,伏安特性和板電流密度分布特性是衡量電除塵器電場特性及極配型式的關(guān)鍵參數(shù)。生物質(zhì)與煤混燃,由于生物質(zhì)與煤物化特性以及燃燒特性上的差異,可能會使得混燃灰在電除塵器內(nèi)部的荷電特性及電場特性發(fā)生一定的變化,從而影響電除塵器對其捕集效率。因此對混燃灰荷電特性、伏安特性以及板電流密度分布特性展開研究具有十分重要的意義。本文將常見的生物質(zhì)燃料玉米秸、花生殼、木頭屑按照占總熱量0、5%、10%、15%、20%、100%的比例分別與無煙煤和煙煤混燃,制成一系列混燃灰。通過采用自行設(shè)計的粉塵總體荷電量測量系統(tǒng)及分級荷質(zhì)比測量系統(tǒng),在5kV直流正高壓條件下電暈荷電,進行混燃灰總體及分級荷質(zhì)比測量。實驗結(jié)果表明:混燃灰荷質(zhì)比隨著生物質(zhì)混燃比增加出現(xiàn)逐漸增大的趨勢,混燃比例越高,混燃灰的荷電特性越強。另外,摻混生物質(zhì)種類對混燃灰的荷電特性有一定影響,玉米秸、花生殼及木頭屑三種生物質(zhì)來看,玉米秸混燃灰荷電特性最強,花生殼次之,木頭屑荷電特性最弱。與此同時,被摻煤種對混燃灰的荷電特性也存在一定的影響。分析認(rèn)為混燃灰荷電特性規(guī)律與其化學(xué)成分、微觀形貌、比電阻等因素有關(guān)。電場特性層面,通過在自行設(shè)計的水平電場伏安特性測定裝置上模擬電除塵器電暈放電,對混燃灰伏安特性進行測定,結(jié)果表明:生物質(zhì)混燃比例對混燃灰樣的伏安特性有著顯著影響。隨著生物質(zhì)的混燃比提高,混燃灰的伏安特性更優(yōu)。玉米秸、花生殼、木頭屑三種生物質(zhì)與煤混燃灰的伏安特性優(yōu)劣程度:玉米秸花生殼木頭屑與煤的混燃灰,而且隨著生物質(zhì)混燃比例的增加,摻混生物質(zhì)種類差別對混燃灰伏安特性的影響程度愈加凸顯。另外結(jié)果還發(fā)現(xiàn)生物質(zhì)與無煙煤混燃灰伏安特性明顯優(yōu)于與煙煤混燃灰,但不同品類的無煙煤之間伏安特性雖存在差異,但差異較小。采用網(wǎng)格型微元電流信號法在自行設(shè)計的板電流密度分布測定裝置上對混燃灰板電流密度分布特性進行研究,結(jié)果表明:生物質(zhì)混燃比以及摻混生物質(zhì)種類僅對混燃灰電流密度大小產(chǎn)生影響,對其電流密度分布均勻性沒有影響。另外電暈線型是影響混燃灰板電流密度分布特性的重要因素。因此對于混燃灰的高效捕集,選擇最佳的極配形式也尤為重要。
[Abstract]:Charge of fly ash particles is the premise and basic process of its capture by electrostatic precipitator. The characteristics of volt-ampere and plate current density distribution are the key parameters to measure the electric field characteristics and pole-matching type of electrostatic precipitator. Because of the difference in the physical and chemical characteristics and combustion characteristics of biomass and coal, the charge and electric field characteristics of the mixed combustion ash in the electrostatic precipitator may be changed to a certain extent. Thus, the capture efficiency of the electrostatic precipitator is affected. Therefore, it is of great significance to study the charge-charging characteristics, volt-ampere characteristics and current density distribution characteristics of mixed combustion ash. In this paper, the common biomass fuel corn straw, peanut hulls and wood dandruff were mixed with anthracite and bituminous coal to form a series of combustible ash according to the proportion of 10% of total heat of corn straw, peanut shell and wood dandruff. By using the self-designed system for measuring the total charge of dust and the measuring system of the graded charging mass ratio, the total and graded charge / mass ratio of the mixed combustion ash was measured under the condition of 5kV DC positive high voltage and corona charge. The experimental results show that the charge / mass ratio of mixed combustion ash increases gradually with the increase of biomass blending ratio, and the higher the blending ratio is, the stronger the charge characteristic of the mixed combustion ash is. In addition, the type of mixed biomass has a certain effect on the charge characteristics of mixed burning ash. Among the three kinds of biomass, corn straw, peanut shell and wood dandruff have the strongest charge-charging characteristics, followed by peanut shell and wood dandruff. At the same time, mixed coal has a certain influence on the charge characteristics of mixed combustion ash. It is concluded that the charge-charging characteristics of mixed combustion ash are related to its chemical composition, microscopic morphology, specific resistance and so on. In the electric field characteristic level, by simulating the corona discharge of the electrostatic precipitator on the self-designed measuring device of the horizontal electric field volt-ampere characteristic, the volt-ampere characteristic of the mixed combustion ash is measured. The results show that the ratio of biomass mixture has a significant effect on the voltammetric characteristics of mixed combustion ash samples. With the increase of the ratio of biomass to fuel, the voltammetric characteristics of mixed combustion ash are better. The voltammetric characteristics of corn straw, peanut shell, wood dandruff and coal mixed combustion ash were good and bad: corn straw peanut shell wood dandruff and coal mixed burning ash, and with the increase of biomass mixed combustion ratio, The influence of different kinds of mixed biomass on the voltammetric characteristics of blended ash is becoming more and more prominent. The results also showed that the voltammetric characteristics of biomass and anthracite blended ash were obviously superior to those of bituminous coal, but the voltammetric characteristics of anthracite of different categories were different, but the difference was small. The characteristics of the current density distribution of the mixed ash plate were studied by using the grid microelement current signal method on the plate current density measurement device designed by ourselves. The results showed that the mixed combustion ratio and the type of mixed biomass had only influence on the current density of the ash, but had no effect on the uniformity of the current density distribution. In addition, the corona pattern is an important factor affecting the current density distribution of the ash plate. Therefore, it is very important to select the best matching form for the high efficiency capture of mixed combustion ash.
【學(xué)位授予單位】：華北電力大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：X701.2

【參考文獻】

相關(guān)期刊論文 前10條

1 張磊;陳曉琴;高旭;周立謙;蔡為民;;基于復(fù)雜有害氣體釋放模型的霧霾氣象條件下煙氣排放影響分析[J];環(huán)境污染與防治;2016年09期

2 趙洪宇;阮海衛(wèi);史晨雪;高戈武;閆晨光;舒新前;;北京市PM_(2.5)理化特性及燃煤對大氣污染的研究進展[J];環(huán)境工程;2015年12期

3 趙曉文;劉丹丹;邱子臣;蘇俊林;;生物質(zhì)氣化燃燒蒸汽鍋爐研制及應(yīng)用[J];冶金能源;2014年04期

4 李卓函;賀超;安毅;邵誠;;線 板式電除塵器中RS芒刺電極放電特性研究[J];中國電機工程學(xué)報;2014年06期

5 曾育鋒;程倍珊;;自制法拉第杯測微小顆粒電荷量[J];實驗技術(shù)與管理;2013年04期

6 胡云鵬;程世慶;孫鵬;謝敬思;張浩;;生物質(zhì)及其與煤摻燒的灰熔融特性研究[J];熱力發(fā)電;2011年10期

7 蔡麗紅;原永濤;呂建q，

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