任哲,卢康博,孙滔,等.正丁醚/柴油混合燃料在单缸柴油机中的燃烧与排放特性研究[J].内燃机工程,2022,43(4):1-11.
正丁醚/柴油混合燃料在单缸柴油机中的燃烧与排放特性研究
Combustion and Emissions of Di-N-Butyl Ether/Diesel Blend in a Single-Cylinder Diesel Engine
DOI:10.13949/j.cnki.nrjgc.2022.04.001
关键词:正丁醚  柴油  混合燃料  发动机  燃烧  排放
Key Words:di-n-butyl ether  diesel  fuel blend  engine  combustion  emission
基金项目:国家自然科学基金项目(51776124)
作者单位E-mail
任哲* 上海交通大学 动力机械与工程教育部重点实验室上海 200240 zzz_ren@sjtu.edu.cn 
卢康博 上海交通大学 动力机械与工程教育部重点实验室上海 200240  
孙滔 上海交通大学 动力机械与工程教育部重点实验室上海 200240  
杨凯 上海交通大学 动力机械与工程教育部重点实验室上海 200240  
石磊 上海交通大学 动力机械与工程教育部重点实验室上海 200240  
韩东* 上海交通大学 动力机械与工程教育部重点实验室上海 200240 dong_han@sjtu.edu.cn 
摘要点击次数: 1120
全文下载次数: 673
摘要:基于一台单缸压燃式发动机,研究了正丁醚(di-n-butyl ether, DnBE)/柴油混合燃料的燃烧与排放特性,并与纯柴油的试验结果进行了对比。分别采用平均指示有效压力(indicated mean effective pressure, IMEP)即发动机负荷0.55 MPa、0.65 MPa、0.75 MPa,废气再循环(exhaust gas recirculation, EGR)率0%、15%、30%,喷油正时上止点后-15°、-10°、-5°、0°及正丁醚掺混体积比20%、40%,综合评估了正丁醚/柴油混合燃料在不同发动机运行工况下的特性。台架试验结果表明:相比于纯柴油,正丁醚的添加使得缸内压力上升相位及放热开始时刻提前,并且在30% EGR率工况下更加明显。在所有测试工况下,正丁醚/柴油混合燃料的预混燃烧比例均小于纯柴油,且第一阶段放热率峰值更低。由于十六烷值的差异,40%正丁醚/柴油混合燃料的着火延迟时间与燃烧持续期更短且燃烧重心更早,表明其具有更快的燃烧速率。试验发现大比例正丁醚/柴油混合燃料的燃烧等容度更高,指示热效率高于纯柴油。此外,添加正丁醚后尾气中的NOx与碳烟排放都会降低,而提高EGR率或推迟喷油均能有效减少NOx的生成。综合而言,添加正丁醚可以有效缓解柴油机中NOx排放、碳烟排放与指示热效率之间的权衡关系。
Abstract:The combustion and emission characteristics of di-n-butyl ether(DnBE)/diesel blend were studied and compared to pure diesel fuel in a single-cylinder compression ignition engine. Engine operational parameters, including engine load, i.e. indicated mean effective pressure(IMEP)(0.55, 0.65 and 0.75 MPa), the exhaust gas recirculation(EGR) rate (0%, 15% and 30%), the fuel injection timing (-15°, -10°, -5° and 0° after top dead center), and the volume fraction of di-n-butyl ether in the fuel blend (20% and 40% in volume) were adjusted to evaluate the engine performances of di-n-butyl ether/diesel blend under changed operation conditions. In comparison to pure diesel fuel, the fuel blends show an earlier pressure rising phase and advanced heat release process, which is more obvious under 30% EGR rate condition. Under all testing conditions, the lower premixed combustion fraction of di-n-butyl ether/diesel blend leads to a lower first-stage heat release peak than diesel fuel. Owing to its higher cetane number, the 40% DnBE/diesel blend features a shorter ignition delay time, a shorter combustion duration, and an earlier combustion centen than diesel fuel, implying a higher combustion rate. The experimental results manifest that the 40% DnBE/diesel blend has a more isovolumetric combustion progress, resulting in a higher indicated thermal efficiency(ITE) than that of pure diesel. Compared with diesel fuel, the nitrogen oxides(NOx) emissions and soot emissions of DnBE/diesel blend are lower, and the NOx emissions can be effectively reduced with the increased EGR rate and delayed injection timing. It is proved that the addition of DnBE can improve the trade-off relationship between NOx emissions, soot emissions, and indicated thermal efficiency in the diesel engine.
查看全文  HTML   查看/发表评论