柴油引燃天然气发动机不同喷射时刻和引燃油量下的燃烧和颗粒排放特性研究  

Combustion and PM Emission Characteristics of Diesel Ignited Natural Gas Engine under Various Diesel Injection Timings and Pilot Delivery

作　　者：周磊[1] 唐利军[1] 宁小康[1] 刘亦夫[1] 曾科[1] 

机构地区：[1]西安交通大学能源动力工程学院,西安710049

出　　处：《内燃机工程》2015年第1期119-124,共6页Chinese Internal Combustion Engine Engineering

基　　金：国家"九七三"重点基础研究发展计划项目(2011CB707200)

摘　　要：在一台改装的柴油引燃天然气发动机上对不同的柴油喷射时刻和引燃油量(喷射油量)下的燃烧和颗粒排放进行了试验研究,并对相关的燃烧和颗粒排放特性进行分析。研究结果表明:随着喷射时刻和引燃油量的变化,柴油引燃天然气发动机的颗粒排放呈现单峰分布,其粒径分布无太大的变化,峰值粒径出现在29nm附近。随着喷射时刻的提前,纳米级颗粒数量浓度显著增加,颗粒的质量浓度呈现先减小后增加的趋势,滞燃期逐渐推迟,总燃烧持续期先减小后缓慢增加,相应的放热率曲线型心在逐渐靠近上止点后逐渐远离;随着引燃油量的增加,柴油引燃天然气发动机滞燃期和总燃烧持续期持续减小,放热率曲线型心逐渐靠近上止点,发动机排放颗粒的数量浓度明显减小,但其颗粒的质量浓度逐渐增加。The combustion and PM emissions under various pilot diesel injection timings and delivery were experimentally investigated in a modified diesel pilot-ignited natural gas engine to analyze the combustion and emission characteristics. Results indicate that particle size distribution curve with variation of pilot diesel injection timing and delivery exhibits unimodal shape, the peak of particle number concentration appears near diameter of 29nm, and the size distribution varies slightly. With injection timing advancing, the particle number concentration especially nanometer particle number concentration obviously increases, and the particle mass concentration exhibits a decrease-increase trend, ignition delay period increases and total combustion duration first shortens and then prolongs slowly, corresponding crank angle of the heat release rate curve center closes to and then leaves TDC gradually. With the pilot delivery increasing, both ignition delay period and total combustion continuously decrease, and the crank angle of heat release rate curve center closes to TDC gradually, meanwhile the particle number concentration evidently decreases and its mass concentration increases unexpectedly.

关 键 词：内燃机 天然气发动机 柴油引燃 颗粒排放 燃烧特性 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]