水泥分解炉内生活垃圾与煤粉燃烧特性分析和技改建议
Analysis of combustion characteristics of RDF and coal in the cement calciner and suggestions for technical improvement
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摘要: 将生活垃圾制备成垃圾衍生燃料（RDF），再投入水泥分解炉内进行燃烧处理是生活垃圾无害化处置的重要途径。与煤粉相比，RDF在分解炉内的燃烧与运动特性存在较大差异，从而对分解炉的正常运转产生较大影响。通过检测分析、热工计算和计算流体动力学模拟（CFD）等手段，对比了RDF与煤粉在燃烧、运动特性等方面存在的差异。结果表明，与煤粉相比，RDF的水分、灰分含量偏高，固定碳含量偏低, 单位RDF燃烧理论空气量只有煤粉的14.5%。入炉煤粉的特征粒径为20 μm，RDF为10 mm；粒径小于10 mm的RDF喂入分解炉后随烟气向下游流动，但大于10 mm的直接向下运动，并在分解炉缩口和中部形成循环。经过空气干燥、粉磨后的RDF颗粒着火温度为235~242 °C，煤粉着火温度为375 °C，然而考虑实际使用时入炉RDF水分含量高、尺寸大等，其在分解炉内燃烧速度通常较煤粉慢。为此，建议水泥企业在对RDF进行准确的工业分析和元素分析基础上，通过热工标定、CFD模拟等手段优化RDF处置尺寸与喂入位置，确保RDF在分解炉内完全燃烧。
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关键词:
- 水泥分解炉 /
- 垃圾衍生燃料（RDF） /
- 燃烧特性 /
- 运动特性
Abstract: Refuse derived fuel (RDF) co-processed in the cement calciner is one of the harmless ways to dispose the domestic waste. Compared with the coal, RDF has many differences on the combustion and motion characteristics, which greatly impact the normal operations of the calciner. Test and analysis, thermal calculation and computational fluid dynamics (CFD) were used to understand the differences between the coal and RDF. Results showed that RDF had a higher water and ash content, and a lower fixed carbon content than the coal. Besides, the theoretical air volume need for the unit RDF combustion was only 14.5% of the air volume for the unit coal. The characteristic particle diameters for the coal and RDF fed into the calciner were 20 μm and 10 mm, respectively. The RDF particles with diameter smaller than 10 mm were carried by flue gas downstream as they were fed into the calciner, while the RDF particles with diameter larger than 10 mm fell down to the throat of the calciner, and then were carried by high speed gas stream to rise, which formed a RDF circulation between the feed spot and calciner throat. The ignition temperature for the air-dried and grinded RDF was 235~242 °C, and for the coal was 375 °C. However, RDF burned slowly in the calciner due to its high content water content and large size. Suggestions were given to the cement enterprises to conduct the proximate analysis and ultimate analysis of the RDF at first, and make it clear of the calciner combustion condition by the thermal condition calibration and CFD, and optimize the RDF feeding size and position to ensure the RDF burning itself out in the calciner. -
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[1] 李晓辉, 杨宏斌, 黄华存, 等. 水泥窑协同处置村镇生活垃圾[J]. 环境工程学报,2016,10(6):3255-3259 10.12030/j.cjee.201501019 [2] 凌永生, 金宜英, 王雷, 等. 苏州市生活垃圾焚烧飞灰水泥窑煅烧资源化示范工程[J]. 环境工程,2008,26(S1):220-223 [3] 王昕, 刘晨, 颜碧兰, 等. 国内外水泥窑协同处置城市固体废弃物现状与应用[J]. 硅酸盐通报,2014,33(8):1989-1995 [4] MUT M D M C.Sulfur release during alternative fuels combustion in cement rotary kilns[D].Copenhagen: Technical University of Denmark,2014 [5] 陈蕾, 杨学权, 辛美静, 等. 城市生活垃圾成分及其波动对水泥窑的影响分析[J]. 水泥,2010(9):19-21 10.3969/j.issn.1002-9877.2010.09.005 [6] 王祖润. 生活垃圾协同处置对烧成系统的影响[J]. 水泥,2017(8):14-16 [7] 中华人民共和国国家质量监督检验检疫总局, 中国国家标准化管理委员会. 煤的工业分析方法仪器法: GB/T30732-2014[S]. 北京: 中国标准出版社,2014 [8] 中华人民共和国国家质量监督检验检疫总局, 中国国家标准化管理委员会. 煤的发热量测定方法: GB/T213-2008[S]. 北京: 中国标准出版社,2009 [9] 中华人民共和国国家质量监督检验检疫总局, 中国国家标准化管理委员会. 煤中的全硫测定方法: GB/T214-2007[S]. 北京: 中国标准出版社,2008 [10] 中华人民共和国国家质量监督检验检疫总局, 中国国家标准化管理委员会. 煤中碳氢氮的测定仪器法: GB/T30733-2014[S]. 北京: 中国标准出版社,2014 [11] 金余其, 严建华, 池涌, 等. 中国城市生活垃圾燃烧的特性[J]. 环境科学,2002,23(3):107-110 [12] 马晓茜, 刘国辉, 余昭胜. 基于CFD 的城市生活垃圾焚烧炉燃烧优化[J]. 华南理工大学学报(自然科学版),2008,36(2):101-106 [13] 梅书霞, 谢峻林, 陈晓琳, 等. 涡旋式分解炉中煤及垃圾衍生燃料共燃烧耦合CaCO3 分解的数值模拟[J]. 化工学报,2017,68(6):2519-2525 [14] RAVI I S, ANDERS B, MIKKO H.CFD modeling to study fluidized bed combustion and gasification[J].Applied Thermal Engineering,2013,52: 585-614 10.1016/j.applthermaleng.2012.12.017 [15] KURNIAWAN K.Studies of fundamental process occurring in pre-calciners and cyclone pre-heater tower using CFD[D].Wales:Cardiff University,2004 [16] 施江, 谢峻林, 梅书霞, 等.RDF 与煤粉混合燃烧特性及动力学分析[J]. 环境工程学报,2017,11(1):490-496 10.12030/j.cjee.201509027 [17] 刘晶晶, 吴奇, 李倦生, 等. 生活垃圾与煤混合燃烧特性及动力学分析[J]. 环境工程学报,2016,10(2):915-921 [18] LIEDMANN B, ARNOLD W, KRüGER B, et al.An approach to model the thermal conversion and flight behavior of refuse derived fuel [J].Fuel,2017,200:252-271 10.1016/j.fuel.2017.03.069 [19] 胡曙光, 聂帅, 朱明, 等. 城市生活垃圾制备水泥窑用衍生燃料的性能分析[J]. 安全与环境学报,2014,14(4):176-180 -
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