Performance and emission characteristics of dual-fuel diesel-gas engines at part loads

摘要

Dual-Fuel Diesel-Gas (D.F.D.G) concept is the most efficient way of using gaseous fuels (LPG or CNG) in conventional diesel engines. So far their operation at full load condition is mostly investigated. However, at part load conditions, theperformance and emission characteristics of D.F.D.G engines are deteriorated. This may be mainly due to overall leaner mixture strength, small amount of pilot jet and misfiring nature of heterogeneous cylinder charge. Since this mode of Operation is veryimportant in vehicle engines, it is worth considering it in more detail. In this work by throttling the inlet air at part load condition, the overall mixture strength of the cylinder charge is modified and brought towards of baseline diesel engine. Theresults show that by throttling the inlet air at carburettor, both emission and performance characteristics of D.F.D.G engine becoming better and approaching that of the baseline diesel engine. For example, performance parameters such as power, torque and thermal efficiency increase and concentration of pollutants such as CO and UHC decrease considerably. In other hand NO{sub}x concentration increases. The results are in good agreement with the results of the other research workers.