光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
Spectroscopy and Spectral Analysis
2015年
10期
2680-2685
,共6页
江建平%骆仲泱%轩俭勇%赵磊%方梦祥%高翔
江建平%駱仲泱%軒儉勇%趙磊%方夢祥%高翔
강건평%락중앙%헌검용%조뢰%방몽상%고상
脉冲电晕放电%电子能量%OH自由基%激光诱导荧光%荧光产率
脈遲電暈放電%電子能量%OH自由基%激光誘導熒光%熒光產率
맥충전훈방전%전자능량%OH자유기%격광유도형광%형광산솔
Pulsed corona discharge%Electron energy%OH radicals%Laser-induced fluorescence%Fluorescence yield
脉冲电晕放电过程中OH自由基等活性基团的空间分布特性对燃煤烟气污染物的氧化脱除具有重要作用。为了探索脉冲电晕放电污染物控制技术的机理,采用激光诱导荧光法检测线板式反应器内部脉冲电晕放电过程中OH自由基的空间二维分布特性,主要研究了不同相对湿度和含氧量对OH自由基空间二维分布特性的影响。实验表明,脉冲电晕放电过程中OH自由基主要存在于线电极下方的区域中,并以线电极为中心面向板电极呈现扇形分布,并且其扇形分布区域的纵向长度和横向宽度的最大值均小于1 cm ;相对湿度的增大有利于OH自由基的生成,促进OH自由基空间二维分布区域面积的扩大,当相对湿度为65%时O H自由基的空间二维分布区域面积达到最大值;当含氧量为2%时最有利于O H自由基的生成,并且O H自由基的空间二维分布区域面积达到最大值,当含氧量超过15%时对O H自由基的生成及其空间二维分布主要起抑制作用。同时,相对湿度和含氧量的增加均提高了激发态OH自由基中猝灭部分所占的比重,从而降低了OH自由基的荧光产率,其中含氧量对OH自由基荧光产率和OH自由基空间二维分布的影响作用大于相对湿度。
脈遲電暈放電過程中OH自由基等活性基糰的空間分佈特性對燃煤煙氣汙染物的氧化脫除具有重要作用。為瞭探索脈遲電暈放電汙染物控製技術的機理,採用激光誘導熒光法檢測線闆式反應器內部脈遲電暈放電過程中OH自由基的空間二維分佈特性,主要研究瞭不同相對濕度和含氧量對OH自由基空間二維分佈特性的影響。實驗錶明,脈遲電暈放電過程中OH自由基主要存在于線電極下方的區域中,併以線電極為中心麵嚮闆電極呈現扇形分佈,併且其扇形分佈區域的縱嚮長度和橫嚮寬度的最大值均小于1 cm ;相對濕度的增大有利于OH自由基的生成,促進OH自由基空間二維分佈區域麵積的擴大,噹相對濕度為65%時O H自由基的空間二維分佈區域麵積達到最大值;噹含氧量為2%時最有利于O H自由基的生成,併且O H自由基的空間二維分佈區域麵積達到最大值,噹含氧量超過15%時對O H自由基的生成及其空間二維分佈主要起抑製作用。同時,相對濕度和含氧量的增加均提高瞭激髮態OH自由基中猝滅部分所佔的比重,從而降低瞭OH自由基的熒光產率,其中含氧量對OH自由基熒光產率和OH自由基空間二維分佈的影響作用大于相對濕度。
맥충전훈방전과정중OH자유기등활성기단적공간분포특성대연매연기오염물적양화탈제구유중요작용。위료탐색맥충전훈방전오염물공제기술적궤리,채용격광유도형광법검측선판식반응기내부맥충전훈방전과정중OH자유기적공간이유분포특성,주요연구료불동상대습도화함양량대OH자유기공간이유분포특성적영향。실험표명,맥충전훈방전과정중OH자유기주요존재우선전겁하방적구역중,병이선전겁위중심면향판전겁정현선형분포,병차기선형분포구역적종향장도화횡향관도적최대치균소우1 cm ;상대습도적증대유리우OH자유기적생성,촉진OH자유기공간이유분포구역면적적확대,당상대습도위65%시O H자유기적공간이유분포구역면적체도최대치;당함양량위2%시최유리우O H자유기적생성,병차O H자유기적공간이유분포구역면적체도최대치,당함양량초과15%시대O H자유기적생성급기공간이유분포주요기억제작용。동시,상대습도화함양량적증가균제고료격발태OH자유기중졸멸부분소점적비중,종이강저료OH자유기적형광산솔,기중함양량대OH자유기형광산솔화OH자유기공간이유분포적영향작용대우상대습도。
Pulsed corona discharge in atmosphere has been widely regarded as an efficient flue gas treatment technology for the generation of active radical species ,such as the OH radicals .The spatial distribution of OH radicals generated by pulsed corona discharge plays an important role in decomposing pollutants .The two‐dimensional (2‐D) distribution of OH radicals of positive wire–plate pulsed corona discharge was detected using laser‐induced fluorescence (LIF) .The influence of relative humidity (RH) and oxygen concentration on the 2‐D distribution of OH radicals were investigated .The results indicated that the 2‐D dis‐tribution of OH radicals was characterized by a fan‐shaped distribution from the wire electrode to plate electrode ,and both the maximum values of vertical length and horizontal width of the fan area was less than 1 cm .The 2‐D distribution area of OH radi‐cals increased significantly with increasing the RH and the optimum condition was 65% RH .The optimal level of the oxygen concentration for the 2‐D distribution area of OH radicals was 2% .The process of OH radical generation and 2‐D distribution ar‐ea of OH radicals were significantly interfered when the oxygen concentration was larger than 15% .The total quenching rate co‐efficients for different RH values and oxygen concentration in this study were used to calculate the fluorescence yield of OH radi‐cal .The fluorescence yield ,which is the ratio between the emission rate (Einstein coefficient) and the sum of the emission rate and quenching rate ,was used to normalize the 2‐D distribution area of OH radicals .The fluorescence yield of OH radical de‐creased with increasing the RH and oxygen concentration linearly and rapidly .It was also found that compared with the RH ,the influence of the oxygen concentration had more notable effect on the fluorescence yield of OH radical and 2‐D distribution area of O H radicals .