Effects of the substitution rate of natural gas on the combustion and emission characteristics in a dual-fuel engine under full load. (December 2017)

• Record Type: Journal Article
• Authors: Lyu, Meng; Zhang, Chunhua; Bao, Xiaofeng; Song, Jiangyong; Liu, Zemin
• Is Part Of: Advances in mechanical engineering. Volume 9:Number 12(2017:Dec.)
• Publication Date: 2017-12
• Subjects: Diesel -- liquefied natural gas -- substitution rate -- combustion characteristics -- exhaust emissions; Mechanical engineering -- Periodicals; 621.05
• DOI: 10.1177/1687814017747158
• Languages: English
• ISSNs: 1687-8132

Abstract

Diesel-piloted natural gas has been considered one of the most promising methods of using natural gas in a compression–ignition engine with few modifications, as this approach benefits from a high thermal efficiency resulting from a high compression ratio. This study experimentally investigated the impact of the natural gas substitution rate on the characteristics of combustion and emissions. Tests were performed under full-load operating conditions at a fixed speed of 1200 r/min with optimized injection timing, and the substitution rate of natural gas was varied with the fixed total fuel energy for different analyses. The in-cylinder pressure, pressure rise rate, heat release rate, cyclic variation of the maximum cylinder pressure ( P max ) and emissions of HC, CO, NOx, and smoke were analyzed. The results indicate that P max and the maximum pressure rise rate initially increase and then decrease as the substitution rate of natural gas increases, whereas the heat release rate and standard deviation of P max increase. Moreover, HC and CO increase as the substitution rate of natural gas increases, whereas NOx and smoke emissions exhibit a trade-off trend.