本文主要研究内容
作者李权（2019）在《管道内障碍物对氢—空气预混火焰传播动力学影响研究》一文中研究指出：随着传统化石能源的消耗,以及其燃烧产物带来的环境问题,寻求新的替代能源变的日趋重要。氢能源具有众多优点,如来源广泛、产物零污染、燃烧热值高,被视为最具前景的新能源。然而由于氢气的特殊性质,如高扩散性、低密度、低点火能和宽点火极限等,使得任何泄漏后的氢气都有可能发生爆燃甚至是爆轰。因此从氢安全角度出发,开展氢-空气预混气体燃烧研究是预防火灾和爆炸事故中最基础、最核心的课题。同时内燃机的燃烧过程也涉及到封闭空间的预混燃烧,其过程包括火焰加速、爆燃转爆轰和准态爆轰等阶段,因此具有重要的工程应用意义。目前关于氢-空气预混火焰研究往往在含有刚性障碍物的管道中,即不可发生形变的障碍物,而对于柔性障碍物、多孔板等特殊结构下预混火焰传播特性关注较少。而开展刚性、柔性障碍物下预混火焰传播的对比研究和多孔板下火焰传播动力学以及焠熄机理的研究对提高氢能源的安全具有至关重要的作用。因此本文主要完成两个研究目标。第一个目标是系统地对比研究刚性、柔性两种障碍物下预混火焰燃烧动力学特性、流场流动特性、火焰传播动态特性及其内在机理和压力变化特性。本文另外一个目标是研究多孔板下火焰传播动力学特性、火焰焠熄极限和火焰焠熄的影响因素。首先,运用高速纹影摄像方法和压力测试技术研究预混火焰经过刚性障碍物的传播机理和其过程中的压力规律。高速摄像机和纹影系统配合用来记录火焰传播形态以及火焰传播速度随传播位置的变化规律。压力传感器用来监测非稳态燃烧过程动态压力变化特性。实验系统考虑了可燃气体当量比、障碍物阻塞比和多个连续障碍物对燃烧动力学的影响。结果表明当量比主要通过影响层流燃烧速度,从而影响流场流动速度和火焰传播。阻塞比主要通过改变流动的截面积,从而影响火焰及其前方的流场的流动压缩效率。在单一刚性障碍物中,火焰主要受流动压缩和流动膨胀影响;而连续障碍物中,火焰初期受流动压缩和膨胀影响,后续的障碍物迅速引起火焰的湍流。且障碍物之间可燃气体的燃烧产物向外膨胀,并在非阻塞区域的的管道内聚集,从而推动火焰面的加速。其次,本文设置了与刚性障碍物同样的工况,对比研究柔性障碍物中预混火焰传播动力学规律。研究表明相较于刚性障碍物中预混火焰传播,柔性障碍物的管道中流场流动、火焰传播动力学特性和压力变化特性存在明显不同。在柔性障碍物中,流场在经过柔性障碍物时发生流动分离,形成附着在障碍物上的剪切流和位于障碍物后方的涡旋结构。柔性障碍物是否发生明显形变是造成两种类型障碍物中预混火焰传播机理差异的主要原因。对于未发生明显形变的柔性障碍物,其火焰传播机理近似于刚性障碍物。而形变的柔性障碍物可以诱导出不同的流场结构,如剪切层和涡旋结构。当火焰在该流场中传播时,剪切层和涡旋结构外缘引起的流动压缩是造成火焰加速的主要机制。并且火焰传播同时受柔性障碍物的动态变化的实际阻塞比影响。柔性障碍物具有多孔结构的特性,可以吸收部分压缩波,从而有效衰减最大压力和压力增加速率。最后,本文通过实验研究了多孔板对氢-空气预混火焰传播动力学的影响。考察了气体当量比、初始压力、孔板几何尺寸以及孔板数量对于火焰传播规律和压力变化的影响。预混火焰通过单一孔板的传播过程时存在四个动力学阶段:层流火焰阶段、射流火焰阶段、湍流火焰阶段和双层火焰阶段。其中在Rayleigh-Taylor(RT)不稳定性的作用下湍流火焰面演化为双层火焰。预混火焰通过不同几何尺寸的孔板时可分为三种传播模式:“go”、“quench”和“near limit”。对于“go”模式,火焰通过孔板存在层流火焰、射流火焰和湍流火焰三个动力学阶段,火焰传播速度和压力随孔板几何尺寸增加而减小。对于“quench”模式,火焰焠熄既可发生火焰通过孔板时,也可以发生在孔板下游。当火焰通过孔板时,多孔结构吸收火焰中的热能,并且降低了燃烧反应中的自由基,从而导致火焰发生焠熄;而当火焰传播至孔板后方时,受湍流影响热的燃烧产物和冷的反应物之间过度混合导致火焰降温,从而导致火焰焠熄。对于“near limit”模式,其传播机制具有以上两种模式的特征,火焰传播至后孔板后方时,同样与冷的反应物混合导致火焰降温,但未发生熄灭,后转变为湍流燃烧。在P0-Φ图中,火焰焠熄极限符线性方程,且结果表明在贫燃料中(Φ<1.0),存在临界焠熄厚度dc(dc<80mm),而在富燃料中(Φ>1.0),未发现临界焠熄孔板厚度。
Abstract
sui zhao chuan tong hua dan neng yuan de xiao hao ,yi ji ji ran shao chan wu dai lai de huan jing wen ti ,xun qiu xin de ti dai neng yuan bian de ri qu chong yao 。qing neng yuan ju you zhong duo you dian ,ru lai yuan an fan 、chan wu ling wu ran 、ran shao re zhi gao ,bei shi wei zui ju qian jing de xin neng yuan 。ran er you yu qing qi de te shu xing zhi ,ru gao kuo san xing 、di mi du 、di dian huo neng he kuan dian huo ji xian deng ,shi de ren he xie lou hou de qing qi dou you ke neng fa sheng bao ran shen zhi shi bao hong 。yin ci cong qing an quan jiao du chu fa ,kai zhan qing -kong qi yu hun qi ti ran shao yan jiu shi yu fang huo zai he bao zha shi gu zhong zui ji chu 、zui he xin de ke ti 。tong shi nei ran ji de ran shao guo cheng ye she ji dao feng bi kong jian de yu hun ran shao ,ji guo cheng bao gua huo yan jia su 、bao ran zhuai bao hong he zhun tai bao hong deng jie duan ,yin ci ju you chong yao de gong cheng ying yong yi yi 。mu qian guan yu qing -kong qi yu hun huo yan yan jiu wang wang zai han you gang xing zhang ai wu de guan dao zhong ,ji bu ke fa sheng xing bian de zhang ai wu ,er dui yu rou xing zhang ai wu 、duo kong ban deng te shu jie gou xia yu hun huo yan chuan bo te xing guan zhu jiao shao 。er kai zhan gang xing 、rou xing zhang ai wu xia yu hun huo yan chuan bo de dui bi yan jiu he duo kong ban xia huo yan chuan bo dong li xue yi ji cui xi ji li de yan jiu dui di gao qing neng yuan de an quan ju you zhi guan chong yao de zuo yong 。yin ci ben wen zhu yao wan cheng liang ge yan jiu mu biao 。di yi ge mu biao shi ji tong de dui bi yan jiu gang xing 、rou xing liang chong zhang ai wu xia yu hun huo yan ran shao dong li xue te xing 、liu chang liu dong te xing 、huo yan chuan bo dong tai te xing ji ji nei zai ji li he ya li bian hua te xing 。ben wen ling wai yi ge mu biao shi yan jiu duo kong ban xia huo yan chuan bo dong li xue te xing 、huo yan cui xi ji xian he huo yan cui xi de ying xiang yin su 。shou xian ,yun yong gao su wen ying she xiang fang fa he ya li ce shi ji shu yan jiu yu hun huo yan jing guo gang xing zhang ai wu de chuan bo ji li he ji guo cheng zhong de ya li gui lv 。gao su she xiang ji he wen ying ji tong pei ge yong lai ji lu huo yan chuan bo xing tai yi ji huo yan chuan bo su du sui chuan bo wei zhi de bian hua gui lv 。ya li chuan gan qi yong lai jian ce fei wen tai ran shao guo cheng dong tai ya li bian hua te xing 。shi yan ji tong kao lv le ke ran qi ti dang liang bi 、zhang ai wu zu sai bi he duo ge lian xu zhang ai wu dui ran shao dong li xue de ying xiang 。jie guo biao ming dang liang bi zhu yao tong guo ying xiang ceng liu ran shao su du ,cong er ying xiang liu chang liu dong su du he huo yan chuan bo 。zu sai bi zhu yao tong guo gai bian liu dong de jie mian ji ,cong er ying xiang huo yan ji ji qian fang de liu chang de liu dong ya su xiao lv 。zai chan yi gang xing zhang ai wu zhong ,huo yan zhu yao shou liu dong ya su he liu dong peng zhang ying xiang ;er lian xu zhang ai wu zhong ,huo yan chu ji shou liu dong ya su he peng zhang ying xiang ,hou xu de zhang ai wu xun su yin qi huo yan de tuan liu 。ju zhang ai wu zhi jian ke ran qi ti de ran shao chan wu xiang wai peng zhang ,bing zai fei zu sai ou yu de de guan dao nei ju ji ,cong er tui dong huo yan mian de jia su 。ji ci ,ben wen she zhi le yu gang xing zhang ai wu tong yang de gong kuang ,dui bi yan jiu rou xing zhang ai wu zhong yu hun huo yan chuan bo dong li xue gui lv 。yan jiu biao ming xiang jiao yu gang xing zhang ai wu zhong yu hun huo yan chuan bo ,rou xing zhang ai wu de guan dao zhong liu chang liu dong 、huo yan chuan bo dong li xue te xing he ya li bian hua te xing cun zai ming xian bu tong 。zai rou xing zhang ai wu zhong ,liu chang zai jing guo rou xing zhang ai wu shi fa sheng liu dong fen li ,xing cheng fu zhao zai zhang ai wu shang de jian qie liu he wei yu zhang ai wu hou fang de guo xuan jie gou 。rou xing zhang ai wu shi fou fa sheng ming xian xing bian shi zao cheng liang chong lei xing zhang ai wu zhong yu hun huo yan chuan bo ji li cha yi de zhu yao yuan yin 。dui yu wei fa sheng ming xian xing bian de rou xing zhang ai wu ,ji huo yan chuan bo ji li jin shi yu gang xing zhang ai wu 。er xing bian de rou xing zhang ai wu ke yi you dao chu bu tong de liu chang jie gou ,ru jian qie ceng he guo xuan jie gou 。dang huo yan zai gai liu chang zhong chuan bo shi ,jian qie ceng he guo xuan jie gou wai yuan yin qi de liu dong ya su shi zao cheng huo yan jia su de zhu yao ji zhi 。bing ju huo yan chuan bo tong shi shou rou xing zhang ai wu de dong tai bian hua de shi ji zu sai bi ying xiang 。rou xing zhang ai wu ju you duo kong jie gou de te xing ,ke yi xi shou bu fen ya su bo ,cong er you xiao cui jian zui da ya li he ya li zeng jia su lv 。zui hou ,ben wen tong guo shi yan yan jiu le duo kong ban dui qing -kong qi yu hun huo yan chuan bo dong li xue de ying xiang 。kao cha le qi ti dang liang bi 、chu shi ya li 、kong ban ji he che cun yi ji kong ban shu liang dui yu huo yan chuan bo gui lv he ya li bian hua de ying xiang 。yu hun huo yan tong guo chan yi kong ban de chuan bo guo cheng shi cun zai si ge dong li xue jie duan :ceng liu huo yan jie duan 、she liu huo yan jie duan 、tuan liu huo yan jie duan he shuang ceng huo yan jie duan 。ji zhong zai Rayleigh-Taylor(RT)bu wen ding xing de zuo yong xia tuan liu huo yan mian yan hua wei shuang ceng huo yan 。yu hun huo yan tong guo bu tong ji he che cun de kong ban shi ke fen wei san chong chuan bo mo shi :“go”、“quench”he “near limit”。dui yu “go”mo shi ,huo yan tong guo kong ban cun zai ceng liu huo yan 、she liu huo yan he tuan liu huo yan san ge dong li xue jie duan ,huo yan chuan bo su du he ya li sui kong ban ji he che cun zeng jia er jian xiao 。dui yu “quench”mo shi ,huo yan cui xi ji ke fa sheng huo yan tong guo kong ban shi ,ye ke yi fa sheng zai kong ban xia you 。dang huo yan tong guo kong ban shi ,duo kong jie gou xi shou huo yan zhong de re neng ,bing ju jiang di le ran shao fan ying zhong de zi you ji ,cong er dao zhi huo yan fa sheng cui xi ;er dang huo yan chuan bo zhi kong ban hou fang shi ,shou tuan liu ying xiang re de ran shao chan wu he leng de fan ying wu zhi jian guo du hun ge dao zhi huo yan jiang wen ,cong er dao zhi huo yan cui xi 。dui yu “near limit”mo shi ,ji chuan bo ji zhi ju you yi shang liang chong mo shi de te zheng ,huo yan chuan bo zhi hou kong ban hou fang shi ,tong yang yu leng de fan ying wu hun ge dao zhi huo yan jiang wen ,dan wei fa sheng xi mie ,hou zhuai bian wei tuan liu ran shao 。zai P0-Φtu zhong ,huo yan cui xi ji xian fu xian xing fang cheng ,ju jie guo biao ming zai pin ran liao zhong (Φ<1.0),cun zai lin jie cui xi hou du dc(dc<80mm),er zai fu ran liao zhong (Φ>1.0),wei fa xian lin jie cui xi kong ban hou du 。
论文参考文献
论文详细介绍
论文作者分别是来自中国科学技术大学的李权，发表于刊物中国科学技术大学2019-07-12论文，是一篇关于氢空气预混火焰论文,柔性障碍物论文,多孔板论文,火焰焠熄论文,剪切层论文,涡旋论文,中国科学技术大学2019-07-12论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自中国科学技术大学2019-07-12论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。
标签：氢空气预混火焰论文; 柔性障碍物论文; 多孔板论文; 火焰焠熄论文; 剪切层论文; 涡旋论文; 中国科学技术大学2019-07-12论文;