进气道喷水对增压直喷汽油机性能的影响  

Influence of port water injection on performance of turbocharged gasoline direct injection engine

作　　者：彭忠 秦静[1,2] 裴毅强[1] 张启锐 宋东先[3] 崔亚彬[3] 左坤峰 袁中营[3] 吴慎超 PENG Zhong;QIN Jing;PEI Yiqiang;ZHANG Qirui;SONG Dongxian;CUI Yabin;ZUO Kunfeng;YUAN Zhongying;WU Shenchao(State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China;Internal Combustion Engine Research Institute,Tianjin University,Tianjin 300072,China;GreatWall Motor Company Limited,Baoding 071000,China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072 [2]天津大学内燃机研究所,天津300072 [3]长城汽车股份有限公司,河北保定071000

出　　处：《中南大学学报（自然科学版）》2020年第9期2595-2603,共9页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51776024)。

摘　　要：基于1台缸内直喷增压汽油机,试验研究不同水油比对加浓和当量比混合气燃烧时的发动机燃烧和排放性能的影响。研究结果表明:在满负荷工况下,当过量空气系数λ为1时,随着水油比增加,燃烧相位推迟,燃烧持续期延长,同时喷水后空气质量流量下降,两者共同导致发动机平均有效压力降低;采用当量比混合气燃烧时,λ为1时的CO,HC和排气烟度与λ为0.88时相比明显降低,而NOx排放量升高;CO,排气烟度和NOx排放量随着水油比增加而降低,而HC排放量升高。在满负荷工况下采用当量比混合气燃烧时,通过喷水能够使发动机抗爆能力提高,点火时刻进一步提前,燃烧相位提前;燃烧相位提前使发动机平均有效压力与未优化点火时刻相比提升0.9%~2.9%,有效燃油消耗率降低2.2%~3.9%。Based on a direct-injection turbocharged gasoline engine,the effects of different water-oil ratios on engine combustion and emissions performance during enrichment and equivalent ratio mixture combustion were experimentally studied.The results show that under full load conditions,when excess air ratio λ is 1,as the wateroil ratio increases,the combustion phase is delayed and the combustion duration is extended.At the same time,the air mass flow rate drops after injecting water,which together causes the average effective engine pressure to decrease.When the equivalent ratio combustion is adopted,the emissions of CO,HC and soot are significantly reduced compared to those when λ is 0.88, while the NOx emissions increase;the CO, soot and NOx emissionsdecrease with the increase of the water-oil ratio, while the HC emissions increase. When the equivalent ratiocombustion is used under full load conditions, the engine's knock resistance ability can be improved by waterinjection, the ignition timing can be further advanced, and the combustion phase can be advanced;theimprovement of the combustion phase improves the engine brake mean effective pressure by 0.9%−2.9%, brakespecific fuel consumption decreases by 2.2%−3.9% compared with the unoptimized ignition timing.

关 键 词：进气道喷水 汽油机 燃烧特性 排放 

分 类 号：TK417[动力工程及工程热物理—动力机械及工程]