A simulation model of a four-stroke spark ignition engine fueled with landfill gases

A simulation model for establishment of performance parameters of a spark ignition engine fueled with landfill gas-methane and landfill gas-hydrogen mixtures is described. A two zone model was employed to estimate combustion duration, ignition lag, associated mass burning rates and performance parameters for various operating conditions in an internal combustion engine. The modeling consists of two main modules: a) a fuel-air and residual gas properties calculation, and b) equilibrium combustion product properties calculation with 13 species of equilibrium combustion products. The fuel-air and residual gas module calculates gas properties required in compression stroke and in an unburned zone of a combustion chamber. The equilibrium combustion products module calculates gas properties for the burned zone during combustion and expansion phases. In addition to engine parameters, combustion duration estimation methods were presented to accommodate the presence of high quantities of diluents such as carbon dioxide and nitrogen in methane to represent landfill gases, generally encountered in practice. Similarly, an effect of addition of hydrogen in landfill gas on performance of a spark ignition engine was also incorporated in the model. The pressure traces and other engine output parameters were modeled and compared with the experimental observations obtained in a variable compression single cylinder four-stroke spark ignition Co-operative fuel research (CFR) engine for different fuels that include methane, landfill gas and landfill gas - hydrogen mixtures and found satisfactory agreement. Matlab was used as the programming software in the model.