压缩比对天然气发动机性能特性影响的试验研究  

Experimental Study on the Effects of Compression Ratio on Natural Gas Engine Performance Characteristics

作　　者：冯仁华 罗振[1] 郭栋 陈昆阳 孙旺兵[1] 石来华 FENG Renhua;LUO Zhen;GUO Dong;CHEN Kunyang;SUN Wangbing;SHI Laihua(Vehicle Engineering Institute,Chongqing University of Technology,Chongqing 400054,China;Key Laboratory of Manufacture and Test Techniques for Automobile Parts,Ministry of Education,Chongqing University of Technology,Chongqing 400054,China;Chongqing Vehicle Test&Research Institute,Chongqing 401122,China)

机构地区：[1]重庆理工大学车辆工程学院,重庆400054 [2]重庆理工大学汽车零部件先进制造技术教育部重点实验室,重庆400054 [3]重庆车辆检测研究院,重庆401122

出　　处：《重庆理工大学学报（自然科学）》2021年第8期66-73,共8页Journal of Chongqing University of Technology：Natural Science

基　　金：国家自然科学基金项目(51975080)。

摘　　要：利用台架试验在某六缸增压中冷、火花点火天然气发动机1400r/min和2000 r/min两种转速下、部分负荷和全负荷上开展了压缩比为11.6、13和14的性能、油耗、燃烧和排放等特性研究。研究结果表明:随着压缩比的提高,发动机的燃油消耗率降低,热效率升高。随着压缩比的提高,发动机燃烧稳定性在1400r/min和2000r/min的中高负荷相对低负荷时更加稳定。压缩比为13时发动机的燃烧滞燃期最短,着火性能较好。发动机燃烧速燃期随着压缩比的增加而增加,尤其在中低负荷时变化较明显。排放方面,氮氧化物(NOx)的排放随着压缩比的增加而增加,且在中大负荷下增加幅度较大,碳氢(HC)的排放在压缩比为13时最低,一氧化碳的排放随着压缩比的增加先升高后降低,而二氧化碳的排放特性和一氧化碳的趋势相反,氧气的排放特性整体上和一氧化碳的排放趋势一致。从发动机燃烧、燃油消耗和排放等综合指标和特性上,发动机在压缩比为13时,整体特性最好。In this paper,the experimental studies were conducted on a six cylinder,turbocharged and intercooled spark ignition(SI)natural gas engine under both full load and partial load at 1400 and 2000 rpm with compression ratio of 11.6,13 and 14.This study is trying to find out the influence on engine performance,fuel consumption,combustion heat release and exhaust of natural gas SI engine under different compression ratio.The results show that the specific fuel consumption decreases and thermal efficiency increases with compression ratio increases of the natural gas engine.In terms of combustion,with compression ratio increases,engine combustion stability at engine medium and high load is better than that at low load at 1400 and 2000 r/min.Furthermore,the ignition delay period is shortest when the compression ratio is 13 which means engine have better ignition performance.The engine rapid combustion period increases with compression ratio increases,and the change is more obvious at low and medium engine load.The results also show that the nitrogen oxide(NO x)emissions increase with compression ratio increases,and the increase amplitude is much larger at engine medium and high load.The hydrocarbon(HC)emissions are the lowest at a compression ratio of 13.As the compression ratio increases,the carbon monoxide(CO)emissions increase first and then decrease.The characteristics of carbon dioxide(CO 2)emissions show a reverse trend to that of carbon monoxide(CO)emission and the emission characteristics of oxygen(O 2)are consistent with that of carbon monoxide(CO)emissions.From the comprehensive index and characteristic of engine combustion,the fuel consumption and emissions,the overall characteristic of engine perform the best when the compression ratio is 13.

关 键 词：天然气发动机 压缩比 性能特性 试验研究 

分 类 号：U464.174[机械工程—车辆工程]