【作者】 王洋； 卫立夏； 尧命发；

【Author】 Yang Wang;Lixia Wei;Mingfa Yao;State Key Laboratory of Engines, Tianjin University;

【机构】 天津大学内燃机燃烧学国家重点实验室；

【摘要】 随着环境的恶化及石油资源的短缺,高效清洁的发动机缸内燃烧技术的研究不断提出并应用。本文提出了基于可控化学反应路径调控的发动机缸内燃烧过程的新概念,即利用燃料的低温重整产物控制燃料在发动机缸内的燃烧过程,实现单一燃料的高效清洁燃烧模式。我们将发动机中的一个汽缸改装成重整缸,利用重整缸将燃料部分氧化成低温重整产物并与二次喷入的燃料一起导入到工作缸中一起燃烧。本文在发动机的典型工况条件下,利用正庚烷作为燃料,从理论上研究了这一新概念的可行性。结果表明,正庚烷的重整产物导入工作缸后可以使其滞燃期缩短6 TDCA。在正庚烷重整产物中,氢过氧基酮和过氧化氢缩短了正庚烷的滞燃期,而氢气和一氧化碳等可以提高正庚烷的层流燃烧速度。有害排放物中的甲醛和1,3-丁二烯的摩尔分数也得到了抑制。更多还原

【Abstract】 Degradation of the environment and scarcity of the crude oil fuel the developments of high efficient and clean combustion strategies for engines. We developed a new strategy for diesel engines, the flexible cylinder engine, based on the controllable reaction pathways by adding the reformed fuel into the fresh fuel to alter the reaction pathways of the combustion in the cylinders and hence to improve the combustion efficiency and to reduce the emissions with a single fuel. By this strategy, the fuel is reformed in a flexible cylinder and is then mixed with the fresh fuel before being introduced into the other normal cylinders. In this work, this strategy was demonstrated by using n-heptane as the model fuel at the typical operating conditions of a homogeneous charge compression ignition engine. It was found that the reformed fuel could reduce the ignition delay time by about 6 TDCA. Among the reformed species, ketohydroperoxides and hydrogen peroxide were the key ones to reduce the ignition delay time. The reformed gas could increase the laminar flame speed, with hydrogen and carbon monoxide being the key species. Finally, the reformed gas may also lower the harmful emissions, such as formaldehyde and 1,3-butadiene.更多还原