毫米级单颗煤粒富氧条件下着火特性实验研究  

Experimental Study on the Ignition Characteristics of Single Coal Particles With Several mms in Diameter at O2/N2 and O2/CO2 Atmospheres

作　　者：刘冰 詹扬[1] 张海[2] 吕俊复[2] LIU Bing;ZHAN Yang;ZHANG Hai;LYU Junfu(North China Power Engineering CO., LTD, Xicheng District, Beijing 100120, China;Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Haidian District, Beijing 100084, China)

机构地区：[1]中国工程顾问集团华北电力设计院工程有限公司,北京市西城区100120 [2]清华大学热科学与动力工程教育部重点实验室,北京市海淀区100084

出　　处：《中国电机工程学报》2018年第11期3267-3274,共8页Proceedings of the CSEE

摘　　要：提出了利用近红外波段单色法测量煤颗粒表面温度的方法,开展了不同粒径的3个典型煤种单颗煤粒在不同炉温、氧气浓度和气氛下的实验研究。实验结果表明,随着氧气浓度的增加,火焰亮度明显增加,大同烟煤颗粒发生挥发分喷射现象,而海拉尔褐煤则没有出现,京西无烟煤均为异相着火;3个煤种的着火温度和着火延迟时间均随氧气浓度增加而降低。在炉温和气氛相同时,着火时刻煤粒的表面温度随粒径的增加呈略微增加的趋势,而中心温度则持续下降,揭示了文献中粒径变化时着火温度实验结果不一致的原因是由于毫米量级煤粒内部存在较大温度梯度造成的。采用CO2代替N2时,煤颗粒的着火延迟时间增加,CO2气氛下氧气浓度的增加对着火的促进作用更明显。A monochromatic imaging technique was developed and applied to retrieve the surface temperature of the coal particle using a short wavelength infrared （SWIR） camera. An experimental study on the effects of oxygen concentration, radius meter and N2/CO2 diluent gas on the ignition and combustion characteristics of mms diameter single coal particle was conducted for three coal ranks. It was found that the flame luminosity increased considerably while ignition delay time and ignition temperature decreased with increasing oxygen concentration. Unlike DT bituminous coal particles, the volatile flame ejection phenomenon do not occur for HLE lignite coal particles. JX anthracite coal particles ignite heterogeneously only. For the same test condition, the particle surface temperature at the ignition moment slightly increase while the inner particle temperature sustainably decrease with increasing particle radius （-mm）. The inconsistent trends of coal particle ignition temperature with increasing particle diameter proposed by other literature are interpreted by the experimental results, which are caused by the large temperature gradient existed in large particles. Compared with O2/N2 atmosphere, the ignition delay time increase and the increasing oxygen concentrations play a more important role in improving ignition behavior at O2/CO2 atmosphere condition.

关 键 词：煤 毫米级颗粒 着火温度 着火延迟时间 内部温度梯度 富氧 O2/CO2气氛 

分 类 号：TQ534[化学工程—煤化学工程]