PDF《生物柴油/DMF 混合燃料对柴油机低温燃烧的影响》

燃烧科学与技术 Journal of Combustion Science and Technology 2017, 23(2): 104-110 DOI 10.

11715/rskxjs.R201510005 收稿日期:2015-11-23. 基金项目:国家重点基础研究发展计划(973 计划)资助项目(2013CB228402);

国家自然科学基金资助项目(51176140). 作者简介:郑尊清(1973― ),男,博士,副研究员. 通讯作者:郑尊清,zhengzunqing@tju.edu.cn. 生物柴油/DMF 混合燃料对柴油机低温燃烧的影响 郑尊清,钟小凡,刘海峰,王小峰,胡斌(天津大学内燃机燃烧学国家重点实验室,天津 300072) 摘要:在生物柴油中分别掺入体积分数 20%,和50%,的2,5-二甲基呋喃(DMF)组成 DMF20 和DMF50 混合燃 料,在一台单缸柴油机上对柴油、生物柴油和生物柴油/DMF 混合燃料开展低温燃烧试验研究.结果表明,生物 柴油和柴油燃烧特性相近,生物柴油含氧特性在一定程度上可以改善低温燃烧的碳烟排放;

增大生物柴油中 DMF 掺混比例,混合燃料十六烷值降低,滞燃期延长,燃烧速率加快,预混放热峰值升高,最大压力升高率增 大,DMF50 即使在高负荷下也呈现典型的预混单峰放热.在低负荷时,掺混燃料热效率并没有优势,随负荷增 大,掺混燃料在热效率方面逐渐表现出优势,特别是 DMF50 在高负荷时优势明显,指示热效率提高到 46.5%,(此 时柴油和生物柴油分别为 43%,和43.3%,).掺混 DMF 对碳烟改善明显,在高负荷、 低温燃烧、 低氧浓度条件下 DMF50 仍可基本实现无碳烟排放,同时提高 DMF 掺混比例对改善高负荷低温燃烧的 CO 和HC 排放作用显著. 关键词:低温燃烧;

生物柴油;

DMF;

掺混比例;

负荷;

碳烟 中图分类号:TK421 文献标志码:A 文章编号:1006-8740(2017)02-0104-07 Effect of Biodiesel/DMF Blended Fuel on Low Temperature Combustion in a Diesel Engine Zheng Zunqing,Zhong Xiaofan,Liu Haifeng,Wang Xiaofeng,Hu Bin (State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China) Abstract:Low temperature combustions of diesel,biodiesel and biodiesel/DMF blends were investigated on a single-cylinder diesel engine. Blended fuels including DMF20 and DMF50 were formulated by blending DMF with biodiesel at 20%, and 50%, volume ratios,separately. The results show that the combustion characteristic of bio- diesel is similar to that of diesel and its fuel oxygen can improve the soot emission of low temperature combustion to some extent. With the increase of blending ratio,the cetane number of blended fuel is reduced and the ignition delay is prolonged,which results in higher burning rate and higher premixed heat release rate,and the maximum pressure rise rate is also increased. For DMF50,the typical premixed mono-peak heat release is presented even under high load condition. At low load,no advantage in thermal efficiency is shown for fuel blends,while as load increases,the fuel blends gradually show the advantage in thermal efficiency. And at high load,the indicated thermal efficiency can be increased up to 46.5%,for DMF50,while the indicated thermal efficiency of diesel and biodiesel are 43%, and 43.3%,,

respectively. The soot emission can be obviously improved by the fuel blends and smoke-free operation can still be realized for DMF50 even under high load low temperature combustion condition with relatively low oxygen concentration. Meanwhile,the CO and HC emissions of low temperature combustion at high load can also be significantly improved by increasing the blending ratio of DMF. 郑尊清等: 生物柴油/DMF 混合燃料对柴油机低温燃烧的影响 燃烧科学与技术 ―