高原状态下甲醇替代率对柴油机燃烧与排放的影响  

Effects of methanol substitution percent on combustion and emission of diesel engines under plateau condition

作　　者：王建[1] 于威 王斌[2] WANG Jian;YU Wei;WANG Bin(School of Automotive and Traffic Engineering,Jiangsu University,Zhenjiang 212000,China;Wuxi Diesel Engine Factory,FAW Jiefang Automobile Co.,Ltd.,Wuxi 214026,China)

机构地区：[1]江苏大学汽车与交通工程学院,江苏镇江212000 [2]一汽解放汽车有限公司无锡柴油机厂,江苏无锡214026

出　　处：《吉林大学学报（工学版）》2023年第4期954-963,共10页Journal of Jilin University:Engineering and Technology Edition

基　　金：江苏省高校优势学科建设工程项目(苏证办发[2015]);江苏重点研发计划项目(BE201518)。

摘　　要：模拟了10 m、700 m及2400 m海拔压力,通过试验探究不同海拔对柴油/甲醇二元燃料发动机缸内燃烧与排放的影响,试验工况为1800 r/min下25%、50%和75%负荷。结果表明:发动机在25%负荷下,2400 m海拔及40%甲醇替代率时会导致缸内出现失火,使峰值压力降低,滞燃期延长,扩散燃烧缩短;在50%与75%负荷下,海拔高度与甲醇替代率的增加使缸内峰值压力明显上升,各工况燃烧持续期随着甲醇替代率的增加而缩短,随海拔的增加而延长。相比于10 m海拔纯柴油模式,在各海拔及甲醇替代率下,发动机的滞燃期最大延长27.01%,最大缩短28.99%;燃烧持续期最大延长22.79%,最大缩短43.20%;CA50前移8.55%~21.82%,缸内平均燃烧温度上升1.45%~23.83%。在50%和75%负荷下,发动机有效热效率随海拔的升高而降低、随甲醇替代率的增加而升高;在25%负荷下,呈现出更复杂的变化规律。污染物排放中,随着甲醇替代率的增加,同一负荷下NOx与烟度同时降低,但HC与CO同时增加;而随着海拔增加,常规污染物排放几乎都呈上升趋势。本研究内容可以为高原地区柴油/甲醇二元燃料发动机缸内燃烧与排放提供参考价值。The altitude pressure of 10 m,700 m and 2400 m were simulated to explore the combustion and emission of diesel-methanol dual fuel engine in different altitude.The test conditions were 25%,50%and 75%load at 1800 r/min.The results demonstrated that under 25%load,misfire emerge in the cylinder at 40%methanol substitution percentage(MSP)and 2400 m,which lead to the peak pressure decrease in the cylinder,the combustion delay period will be prolonged,and the diffusion combustion will be shortened.Under 50%and 75%loads,the increasing of altitude and MSP result in peak pressure increasing in the cylinder.The combustion duration decreases with the increasing of MSP and increases with the increasing of altitude in all conditions.Compared with the pure diesel mode in 10 m,under different altitudes and MSP,the maximum ignition delay period of the engine is extended by 27.01%and the minimum is shortened by 28.99%.The maximum combustion duration is shortened by 43.20%and extended by 22.79%,the CA50 moves forward by 8.55%~21.82%,and the in-cylinder combustion temperature rises by 1.45%~23.83%.The brake thermal efficiency of the engine decreases with the increase of altitude and increases with the increase of MSP at 50%and 75%loads.However,brake thermal efficiency presents a more complex variation rule under 25%load.Among the pollutant emission,with the increase of MSP,NOx and Soot decreased simultaneously,HC and CO increased simultaneously under the same load.With the increase of altitude,the emission almost all showed an upward trend.The research can provide reference for the in-cylinder combustion and emission of diesel/methanol dual fuel engine in the plateau area.

关 键 词：动力机械工程 柴油/甲醇二元燃料 海拔高度 燃烧 排放 

分 类 号：TK428.9[动力工程及工程热物理—动力机械及工程]