CH_(2)O链长对PODE/柴油混合燃料喷雾燃烧特性的影响  

Effects of the CH_(2)O chain length on the spray combustion characteristics of PODE/diesel blends

作　　者：常晓龙 赵玉伟 王小琛 陈占明 孙亚松 肖红亮 CHANG Xiaolong;ZHAO Yuwei;WANG Xiaochen;CHEN Zhanming;SUN Yasong;XIAO Hongliang(School of Energy and Electrical Engineering,Chang'an University,Xi'an 710018,China;Air and Missile Defense College,Air Force Engineering University,Xi'an 710051,China;Ningbo C.S.I.Power&Machinery Group Co.,Ltd,Ningbo 315000,China)

机构地区：[1]长安大学能源与电气工程学院,西安710018 [2]空军工程大学防空反导学院,西安710051 [3]宁波中策动力机电集团有限公司,宁波315000

出　　处：《农业工程学报》2025年第7期222-229,F0003,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(52106191);陕西省自然科学基金项目(2023-JC-QN-0517);长安大学青年学者学科交叉团队建设项目(300104240913)。

摘　　要：为明晰不同CH_(2)O链长的聚甲氧基二甲醚(polyoxymethylene dimethyl ether,PODE,其分子式为CH_(3)O(CH_(2)O)_(n )CH_(3),其中链长n≥2,一般取值小于8,本文中n=2,3,4,分别记为PODE_(2)、PODE_(3)、PODE_(4))对柴油喷雾燃烧特性的影响,该研究在可视化定容燃烧弹测试平台上,利用纹影法和直拍法对比分析了不同喷射压力下柴油/PODE_(2)、柴油/PODE_(3)、柴油/PODE_(4)三种混合燃料的喷雾燃烧特性。结果表明,环境温度为500 K的氮气氛围下,加入PODE后喷雾贯穿距增加,但喷雾锥角和喷雾面积减小。随着PODE中CH_(2)O链长的增加,柴油/PODE混合燃料的喷雾贯穿距和喷雾面积均呈增大趋势,但平均喷雾锥角减小;随着喷射压力的增加,混合燃料的喷雾贯穿距、喷雾锥角和喷雾面积均呈增大趋势。环境温度为823 K的空气氛围下,与柴油喷雾火焰相比,加入PODE后火焰发光强度下降,滞燃期和火焰浮起长度明显缩短;且随着喷射压力的增加,火焰发光强度和滞燃期降幅更加明显。随着PODE中CH_(2)O链长的增加,柴油/PODE的火焰发光强度逐渐下降,滞燃期和火焰浮起长度逐渐缩短。这说明,PODE中CH_(2)O链长越长,越利于减少碳烟排放,实现清洁燃烧。结果表明,加入PODE后能明显改善柴油喷雾的着火并降低碳烟排放;且随着PODE中CH_(2)O链长的增加,其改善效果更为显著。结果可为PODE燃油调配及其与发动机的协同优化提供参考。Spray and combustion of the fuel can dominate the formation of fuel/air mixture,even subsequently the in-cylinder combustion and pollutant generation.Polyoxymethylene dimethyl ether(PODE)have emerged as promising alternative fuels for diesel engines,in order to decarbonize agricultural applications.This study aims to investigate the impact of blending PODE with various CH_(2)O chain lengths on the spray combustion of diesel fuel.Three fuel blends were compared on the diesel/PODE_(2),diesel/PODE3,and diesel/PODE_(4) under various ambient conditions and different injection pressures.The experiments were conducted in a visualized constant-volume combustion chamber.Thus the spray development images were captured via the schlieren and combustion images through direct photography.Homemade software was utilized to extract the spray parameters,such as spray tip penetration,spray cone angle,and spray area from the schlieren images,while spray combustion parameters were derived from the combustion images,including ignition delay times,flame lift-off length,and integrated natural flame luminosity.The results revealed that the addition of PODE increased the spray tip penetration,but decreased both the spray cone angle and spray area.The spray tip penetration of the diesel/PODE blends further increased,as the CH_(2)O chain length in PODE increased.The higher density of the fuels was attributed to the fuel atomization,rather than kinematic viscosity.Meanwhile,the spray cone angle decreased with the increasing CH_(2)O chain length,indicating that the kinematic viscosity was dominated.The spray area exhibited an increasing trend with the longer CH_(2)O chain lengths,thus resulting from the combined effects of spray tip penetration and spray cone angle.Additionally,the increasing injection pressure led to a rising trend in the spray tip penetration,spray cone angle,and spray area for the blended fuels.The integrated natural flame luminosity decreased at an ambient temperature of 823 K and the air atmosphere,as the CH_(2)O chain l

关 键 词：柴油 燃烧 聚甲氧基二甲醚(PODE) CH_(2)O链长 喷射压力 柴油/PODE混合燃料 

分 类 号：TK428.9[动力工程及工程热物理—动力机械及工程]