摘要
为探究不同海拔条件下甲醇/柴油反应活性控制压燃(reactivity controlled compression ignition, RCCI)发动机的运行特性,该研究基于甲醇/柴油双燃料发动机试验台架,试验研究1 800 r/min、100%负荷和3 200 r/min、100%负荷下不同甲醇替代率、柴油喷射正时对发动机燃烧与排放性能的影响规律。结果表明:不同海拔条件下随着甲醇替代率的增加,缸压和瞬时放热率峰值逐渐升高,燃烧始点和燃烧中心前移,当量有效燃油消耗率(equivalent brake specific fuel consumption, ESFC)降低,有效热效率升高,NO_x和碳烟排放大幅降低,THC(total hydrocarbons)和CO排放增加。1 800 r/min、100%负荷工况下,甲醇替代率由0增至20%,0、1 000、2 000 m海拔下最大缸压平均增加1.72 MPa,瞬时放热率峰值平均升高25.08 J/(°),ESFC平均降低4.67%,有效热效率平均升高4.90%,NO_x和碳烟排放分别平均降低16.63%和50%,THC和CO排放量分别平均增加142.03、388.18 mg/kg。3 200 r/min下甲醇替代率由0增至7%,不同海拔高度下ESFC平均降低1.76%,有效热效率平均升高1.79%,NO_x和碳烟排放量分别平均降低8.17%和20.70%。海拔高度由0升至2 000 m,1 800 r/min、20%甲醇替代率与3 200 r/min、7%甲醇替代率下,瞬时放热率峰值分别降低4.80和8.08 J/(°),燃烧中心分别推迟1.44°和1.43°,有效热效率分别降低0.82%和0.68%,ESFC分别升高2.10%和1.99%,NO_(x)排放量分别减少10.61%和7.35%,碳烟排放分别增加26.54%和32.12%,THC排放分别升高29.88%和15.45%,CO排放量分别增加22.42%和18.15%。固定甲醇替代率后,随着柴油主喷正时提前,不同海拔条件下缸压和放热率峰值逐渐升高,燃烧中心向上止点靠近,ESFC逐渐降低,有效热效率升高,碳烟排放减少,NO_(x)、THC和CO排放增加。1 800 r/min、15%甲醇替代率下,主喷正时从-1.5°提前至-7.5°,不同海拔高度下ESFC平均降低8.27%,有效热效率平均升高9.08%,碳烟排放平均减少90.94%。为提升高海�
Diesel engines are required for the combination of low or zero-carbon renewable alternative fuels and highefficiency combustion strategies,particularly with the increasingly stringent emission regulations and carbon dioxide(CO2)emission limits.Methanol-diesel dual-fuel reactivity controlled compression ignition(RCCI)combustion can be expected to realize higher thermal efficiency and ultra-low nitrogen oxides(NO_(x))and soot emissions.However,it is still lacking on the performance of the methanol-diesel dual-duel RCCI at high altitudes.This study focused on the combined effects of methanol substitution rate(MSR),main injection timing(MIT)and altitude environment on the combustion process,performance,and emission in the methanol-diesel RCCI engines.The parametric experiments were performed to change the MSR,MIT and altitude at 1800 and 3200 r/min.Firstly,the impacts of MSR at different altitudes(2000,1000,and 0 m)on combustion,engine fuel economy and emissions were investigated under various engine speed and load conditions.A comparison was made with the conventional diesel combustion(CDC)running.Secondly,the effects of MIT at different altitudes on the combustion process,emissions and performance characteristics were experimented with,while the MSR was maintained constant.The results showed that the maximum in-cylinder pressure and peak heat release rate gradually increased with the increase in MSR,while the start of combustion(SOC)and CA50 were advanced.The equivalent brake specific fuel consumption(ESFC),the NO_(x) and soot emissions were reduced significantly,whereas,the brake thermal efficiency(BTE),the THC and CO emissions increased at different altitudes.With the MSR increased from 0 to 20%at 1800 r/min engine speed at 100%load,the maximum in-cylinder pressure increased by 1.72 MPa on average,the PHRR increased by 25.08 J/(°)on average,the ESFC decreased by an average of 4.67%,the BTE increased by an average of 4.90%,the NO_(x) and soot emissions decreased by an average of 16.63%and 50%respectively,and the
作者
黄粉莲
佘超杰
万明定
杨仕臣
雷基林
申立忠
HUANG Fenlian;SHE Chaojie;WAN Mingding;YANG Shichen;LEI Jilin;SHEN Lizhong(Yunnan Key Laboratory of Internal Combustion Engines,Kunming University of Science and Technology,Kunming 650500,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2024年第5期71-81,共11页
Transactions of the Chinese Society of Agricultural Engineering
基金
云南省基础研究计划项目(202301AT070435)
云南省重点研发计划专项(202103AA080002)。
关键词
甲醇
柴油机
反应活性控制压燃
主喷正时
海拔
methanol
diesel engine
reactivity controlled compression ignition
main injection timing
altitude
