Effect of partially premixed and hydrogen addition on natural gas direct-injection lean combustion

• Published in: International journal of hydrogen energy Vol. 34; no. 22; pp. 9239 - 9247
• Main Authors: Wang, Jinhua, Huang, Zuohua, Zheng, Jianjun, Miao, Haiyan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-11-2009; Elsevier
• Subjects: Applied sciences; Combustion; Combustion of gaseous fuels; Combustion. Flame; Direct-injection combustion; Energy; Energy. Thermal use of fuels; Equivalence ratio; Exact sciences and technology; Hydrogen; Kernels; Natural gas; Partially premixed; Propagation; Spark ignition; Theoretical studies. Data and constants. Metering; Trends; Vessels; Partially premixed; Hydrogen; Natural gas; Direct-injection combustion; Spark ignition; Gas mixture; Lean mixture; Premixed flame; Combustion; Direct injection
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2009.09.018

Effect of partially premixed mixture and hydrogen addition on natural gas direct-injection lean combustion was studied experimentally using a constant volume vessel. Flame propagating photos and pressure derived combustion parameters were analysed at different premixed ratios (from 0% to 80%) and hydrogen fractions (from 0% to 40%) at overall equivalence ratio of 0.6, 0.8 and 1.0, respectively. The results show that the flame kernel is concentrated to the spark position with the increase of premixed ratio and/or hydrogen fraction. Flame propagating speed is decreased with the increase of premixed ratio while it increases as hydrogen is added to natural gas. Hydrogen addition has little effect on the partially direct-injection natural gas combustion at the stoichiometric fuel-air mixture condition and all premixed ratios. However, hydrogen addition significantly enhances the combustion rate of natural gas direct-injection combustion at lean mixture condition. Both the initial and main combustion durations are increased with the increase of premixed ratio, while they show the decreasing trend as hydrogen is added to natural gas at the lean mixture condition. Partially premixed direct-injection combustion combining with hydrogen addition can achieve the stable spark ignition and fast combustion at the lean mixture condition.