Design and Construction Methodology of a Stratified Torch Ignition System

It developed a design and construction methodology of a stratified charge torch ignition system for an Otto engine aiming fuel consumption and pollutant emission reduction. The torch ignition system is made of a combustion pre-chamber equipped with a direct fuel injector, an air injector and a spark plug. Fuel is directly injected in the pre-chamber aiming the formation of a lightly rich air fuel mixture. The combustion process starts in the pre-chamber and as the pressure rises, combustion jet flames are produced through interconnection nozzles into the main chamber. The high thermal energy of the jet flames reduces the combustion time, increases the combustion efficiency and allows the engine to efficiently burn lean air fuel mixture of several kinds of fuel in the main chamber, even those that are difficult to ignite. After the combustion takes place in the pre-chamber, air is also injected to help the exhaust process of the combustion products of the previous cycle. Theoretical calculus was made to determine the main geometrical parameters of the pre-chamber, such as volume and the number and diameter of the interconnection nozzles. Since the system designed is equipped with two independent fuel injection systems, one for the pre-chamber and another for the main chamber, it is possible to burn an stoichiometric air fuel mixture in the pre-chamber and a lean air fuel mixture of a different fuel in the main chamber. Therefore a multifuel stratified charge torch ignition engine is obtained.