Optical Diagnostics Study on the Effect of Mixture Preparation on Soot Formation on a Turbocharged Port Fuel Injection SI Engine
With the Limits and Measurement Methods for Emissions from Light-duty Vehicles(CHINA 6)issued, the OEMs need to meet the new legislation in Chinese market in the future. For cost-sensitive market segment, the turbocharged port fuel injection(TPFI)SI engine is still a suitable selection. In order to reduce the soot emissions of TPFI engines further, it is necessary to understand the mixture preparation process, combustion process and the soot formation mechanisms. In this paper, optical diagnostics was used to observe charge motion, mixing and combustion processes of a TPFI engine, with optical access to both the intake manifold and the com- bustion chamber. The results show that wall wetting and fuel film strip atomization as well as flow back were observed in the fuel-air mix- ing process at partial load, and it didn”t cause soot emission seriously. However, at high load, the mixing quality in the intake port be- comes unsatisfactory, spray-wall impingement and wall wetting become exacerbate, and the fuel film motion and deposition in- creased. Through the in-cylinder visualization, it”s found that a large number of liquid fuel droplets enter the cylinder with the valve opened, and the valve gap and spark plug gap area accumulates a large number of fuel film. When the combustion process carried out, diffusion flames which associated with soot formation can be observed. The soot emission mainly sourced from the area of valve and spark plug gap.
mixture preparation soot formation optical diagnostics TPFI engine
Liu Fafa Tian Bo Tian Yingxin Li Qi Shen Huixian Zhan Zhangsong Li Weijian
Powertrain R&D Institute, Chongqing Changan Automobile Co. Ltd.
国内会议
上海
英文
581-587
2017-10-24（万方平台首次上网日期，不代表论文的发表时间）