Combustion, performance, regulated and unregulated emissions of a diesel engine with hydrogen addition

J. H. Zhou, Chun Shun Cheung, Chun Wah Leung

Research output: Journal article publicationJournal articleAcademic researchpeer-review

118 Citations (Scopus)


An experimental investigation was conducted on the combustion, performance, regulated and unregulated emissions of a diesel engine with naturally aspirated hydrogen at the engine speed of 1800revmin-1under five engine loads. Hydrogen was added to provide 10%, 20%, 30% and 40% of the total fuel energy. Improvement of engine performance can be achieved at medium to high loads. At 90% load, abnormal combustion occurs with more than 30% hydrogen addition as indicated by the drastic increase of peak heat release rate, shortened ignition delay and combustion duration. CO/CO2and seven kinds of unregulated emissions (except for formaldehyde) can be efficiently reduced. More than 30% of hydrogen addition can reduce the HC emission at low to medium loads. The percentage reduction of NOxemission is engine load dependent, being positive at low loads and negative at high loads. Drastic increase of NO2is observed at low to medium engine loads. Reductions on particulate mass concentration, particle number concentration and diesel thermal pyrolysis intermediates (olefins and benzene) are associated with the inhibition of polycyclic aromatic hydrocarbons (PAHs) formation. All the unregulated emissions increase at 90% load.
Original languageEnglish
Pages (from-to)1-12
Number of pages12
JournalApplied Energy
Publication statusPublished - 1 Aug 2014


  • Combustion
  • Diesel engine
  • Hydrogen
  • Particle emission
  • Unregulated emissions

ASJC Scopus subject areas

  • Building and Construction
  • Energy(all)
  • Mechanical Engineering
  • Management, Monitoring, Policy and Law

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