Effects of various intake valve timings and spark timings on combustion, cyclic THC and NOX emissions during cold start phase with idle operation in CVVT engine

다국어 초록 (Multilingual Abstract)

In a gasoline SI engine, valve events and spark timings put forth a major influence on overall efficiency, fuel economy,

and exhaust emissions. Residual gases controlled by the valve overlap can be used to reduce NOx emissions and

the spark retardation technique can be used to improve raw THC emissions and catalyst light-off performance during

the cold start phase. This paper investigated the behaviors of the engine and its combustion characteristics with various

intake valve timings and spark timings during the fast idle condition and cold start. And cyclic THC and NOx emissions

were measured at the exhaust port and their formation mechanisms were examined with fast response gas analyzers.

As a result, THCs and NOx were reduced by 35% and 23% with optimizing valve overlap and spark advance during

the cold transient start phase. Consequently, the valve events and ignition timings were found to significantly affect

combustion phenomena and cold-start emissions.

참고문헌 (Reference)

1 S. Schurov, "Time resolved measurement of cold start HC concentration using the fast FID" SAE 1996

2 명차리, "Theoretical Flow Analysis and Experimental Study on Time Resolved THC Formation with Residual Gas in a Dual CVVT Engine" 한국자동차공학회 8 (8): 697-704, 2007

3 F. Zhao, "Technologies for Near-Zero-Emission Gasoline-Powered Vehicles" SAE international 2007

4 M. Peckham, "Real time in-cylinder and exhaust NO measurements in a production SI engine" SAE 1998

5 H. Santoso, "Mixture preparation and hydrocarbon emissions behaviors in the first cycle of SI engine cranking" SAE 2002

6 C. E. Roberts, "Investigation of intake timing effects on the cold start behavior of a spark ignition engine" SAE 1999

7 J. B. Heywood, "International Combustion Engine Fundamentals" McGraw-Hill 1988

8 H. Kwak, "Experimental investigation on the time resolved THC emission characteristics of liquid phase LPG injection (LPLi) engine during cold start" 86 : 1475-1482, 2007

9 이학범, "Effects of Various VVA Systems on the Engine Fuel Economy and Optimization of a CVVT-VVL SI Engine Using 1D Simulation" 한국자동차공학회 8 (8): 675-685, 2007

10 T. Kidokoro, "Development of PZEV exhaust emission control system" SAE 2003

11 J. M. Sung, "Analysis on cycle-by-cycle NO emissions from an SI engine with fast NO analyzer" 10 (10): 73-79, 2002

12 G. B. Parvate-Patil, "An assessment of intake and exhaust philosophies for variable valve timing" SAE 2003