Performance and Emissions of a
Direct-Injection Engine Fueled with Natural Gas/Hydrogen Blends
Wang Jinhua, Huang Zuohua, Liu Bing, Zeng Ke, Yu Jinrong, Jiang Deming
(State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University,
Xi'an 710049, China)
Abstract: An experimental study was conducted on performance and emissions of a
direct-injection spark ignited engine fueled with natural gas £¯hydrogen blends.The
results show that for a fixed fuel injection duration, the brake mean effective pressure
and effective thermal efficiency would decrease with the addition of hydrogen in natural
gas when hydrogen addition fraction is small and would increase with the increase of
hydrogen fraction in natural gas when hydrogen fraction reaches up to 5 percent to 10
percent. This phenomenon is more obvious in the case of lean combustion, indicating a
strong influence of hydrogen addition on lean mixture combustion. The exhaust HC and CO2
decreased with the increase of hydrogen fraction in natural gas, and this would be due to
the increase in H£¯C ratio and excessive air ratio. Under the circumstance of lean
mixture combustion, exhaust NOxdecreased slightly with the increase of
hydrogen addition while exhaust CO had little variation with hydrogen addition.
Keywords: natural gas; hydrogen; performance; emissions; direct-injection; engine