火花点火发动机燃用天然气掺氢混合燃料循环变动研究  

Study of Cycle-by-Cycle Variations of a Spark Ignition Engine Fueled with Natural Gas/Hydrogen Blends

作　　者：陈浩[1] 刘兵[1] 王金华[1] 黄佐华[1] 苗海燕[1] 王锡斌[1] 蒋德明[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,陕西西安710049

出　　处：《内燃机学报》2009年第1期18-24,共7页Transactions of Csice

基　　金：国家自然科学基金项目(50636040);国家重点基础研究计划项目(2007CB210006);国家863计划项目(2006AA11A1B7)

摘　　要：在火花点火天然气发动机上开展了不同掺氢比天然气掺氢混合燃料(氢气在混合燃料中的体积分数为0%、12%、23%、30%和40%)循环变动的试验研究,试验工况点对应于发动机中低负荷。分析了掺混氢气对天然气发动机循环变动的影响。研究结果表明:在稀燃条件下,随着掺氢比的增加,缸内最高压力、最大压力升高率以及平均指示压力均增加。随着掺氢比增加,缸内最高压力与其对应的曲轴转角之间和最大压力升高率与其对应的曲轴转角之间的相关性更强。在化学计量比或浓燃时,掺混氢气可以维持平均指示压力的循环变动系数在较低的水平。在稀燃时,平均指示压力的循环变动系数随掺氢比增加而降低。平均指示压力的循环变动系数达到10%所对应的过量空气系数随掺氢比增加而增加,表明天然气掺混氢气扩展了天然气发动机的稳定稀燃极限。Study of cycle-by-cycle variations of a spark ignition engine fueled with natural gas/hydrogen blends was investigated. Natural gas/hydrogen blends with hydrogen volumetric fraction in the fuel blends of 0% , 12% , 23% , 30% and 40% were experimentally studied. The effect of hydrogen addition on the cycle-by-cycle variations of the natural gas engine operation was analyzed. The results showed that the maximum pressure rise, the maximum rate of pressure rise and the indicated mean effective pressure increased and their corresponding cycle-by-cycle variations decreased with the increase of hydrogen fraction in the blends under lean mixture condition. The above parameters and their corresponding crank angles show the higher inter-dependency with the increase of hydrogen fraction at lean mixture operation. The coefficient of variation of the indicated mean effective pressure （COVimep） maintained at the low level under stoichiometric and relatively rich mixture operation while it decreased with the increase of hydrogen fraction under lean mixture operation. The corresponding excessive air ratio at COVimep = 10% would extend to the leaner mixture with the increase of hydrogen fraction and this indicated that the stable lean limit of natural gas engine could be extended with hydrogen addition.

关 键 词：天然气 氢气 循环变动 火花点火发动机 

分 类 号：TK431.2[动力工程及工程热物理—动力机械及工程]