Numerical study on the combustion process of a biogas spark-ignition engine

Abstract

The fuel called biogas is obtained through anaerobic digestion of different types of organic waste, providing a way to tap the energy stored in organic matter. The use of this fuel is also attractive from the standpoint of global warming because its application does not register a net emission of carbon dioxide into the atmosphere. One possible use for this fuel is to feed the spark-ignition internal combustion engines. In the present, there is little information available about the process of combustion in internal combustion engines fueled by biogas. The combustion process of an internal combustion engine ignition powered by biogas is characterized in terms of the duration of combustion, i.e., depending on the time elapsed while the reactants (methane and oxygen) are transformed into products (mainly carbon dioxide and water). This study numerically evaluates the way in which the geometrical parameters such as the compression ratio and operating parameters like engine speed, the excess air, the time of spark timing and carbon dioxide content of biogas affect the evolution of the combustion process. To carry out this study, a five factors and two levels experiment was designed and conducted, based on which, the most influential parameters were identified. Equations expressing the combustion characteristic parameters, as a function of the geometric and operation parameters of a spark ignited engines, are delivered as a result

Composition and Stoichiometry Effects of Biogas as Fuel in Spark Ignition Engine

“…we notice that the dilution of the fuel by CO2 causes a homogeneous penetration of the flame in the combustion chamber. The lower is dilution, the more the penetration of the flame is fast and occupying the maximum of the volume of the combustion chamber, especially for rich mixtures [25]. In addition, we observe that for the same equivalence ratio ϕ, the presence of different concentrations of CO2 modifies considerably the propagation of the flame.…”

“…The right combination of fuel and operating characteristics is such that knock is avoided or almost avoided. The process of combustion in SI engines depends strongly on the field speed and the level of turbulence in the combustion chamber at the time of spark ignition; it depends also on the pressure, temperature, and the mixing gas in the cylinder [25].…”

Hydrogen-natural gas combustion in a marine lean-burn SI engine: A comparitive analysis of Seiliger and double Wiebe function-based zero–dimensional modelling

“…al. performed CFD calculations to determine single Wiebe function coefficients as a function of compression ratio, engine speed, air-excess, spark timing and carbon dioxide content to study biogas combustion [34]. Similarly, Rousseau et.al.…”

A thermodynamic work cycle simulation of a syngas-fueled engine

“…In order to take into consideration the effect of the excess-air ratio on the heat-release rate, a Vibe correlation for a biogas-fueled engine, obtained by Carrera et al [6,7] has been used. It quantifies the Vibe BDUR , a and m parameters as functions of the compression ratio, engine speed, excess-air ratio, Start of Combustion angle and the CO 2 volumetric fraction in the fuel as follows:…”