GASEOUS EMISSIONS AND COMBUSTION EFFICIENCY ANALYSIS OF HYDROGEN-DIESEL DUAL FUEL ENGINE UNDER FUEL-LEAN CONDITION

摘要

Exhaust gas emissions from diesel engine combustion using alternative fuel may change in their quantities that can affect exhaust gas after-treatment devices and environmental ambient. This study presents theoretical analysis of combustion generated emissions and efficiency of hydrogen-diesel duel fuel in fuel-lean condition. A chemical equilibrium method by minimizing Gibbs free energy is employed to estimate exhaust gas products from diesel and hydrogen-diesel mode combustion. The combustion products, e.g., unburned hydrocarbons (CH_4), hydrogen (H_2), carbon dioxide (CO_2), carbon monoxide (CO) are comparatively investigated, based upon similar specific energy input. Subsequently, the obtained combustible products (CH_4, H_2 and CO) are used to calculate combustion efficiency, based upon chemical energy left in waste exhaust gases. The main findings are associated with the reduction in CO_2 corresponding to the increase in combustion efficiency in hydrogen-diesel combustion mode, depending on relative air-to-fuel ratios. Meanwhile, the CH_4, H_2 and CO contents in the flue gas increase in the operating conditions used.