Examination of the Performance of a Dual Fuel Diesel Engine with ParticuIar Reference to the Presence of Some Inert Diluents in the Engine Intake Charge

An examination of the combustion phenomena and associated engine performance is made for a dual fuel engine of the compression ignition type when additional auxiliary fuels and inerts were introduced with the main intake charge. This was considered to have direct relevance to operation of diesel engines on low heating value gaseous fuel mixtures. A single cylinder direct injection diesel engine was employed throughout. H₂, CH₄, CO₂ and N? were the gas constituents used.

Operation on gaseous fuel mixtures containing significant amounts of diluent inerts showed a marked deterioration of the already inefficient combustion of lean fuel-air mixtures. Of the two inert gases (CO₂ and N₂) introduced in turn, CO₂ has a comparatively greater influence in narrowing the operating range of the engine.

Both diesel and dual fuel operations were also considered when a spray of water was introduced into the intake of the engine. The quenching of the charge resulting from water addition appeared to slow down the combustion rates, necessitating the supply of a certain minimum amount of gaseous fuel and diesel pilot for adequate combustion.