Evaluation of the Effect of Fuel Properties on the Fuel Spray and Jet Characteristics in a HGV DI Diesel Engine Operated by Used Cooking Oils

Abstract

Fuel injection systems in modern diesel engines are designed and built to comply with very stringent environmental standards. They should also meet the highest level of fuel economy. Drivability, rapid response and easy and accurate control are a common demand. Changing the fuel characteristics could affect the performance of the fuel injection system. This study focuses on the evaluation of fuel spray characteristics of straight used cooking oil (SUCO) and its blends with petroleum diesel (PD) as a surrogate for pure PD. Used cooking oil blends have quite different physical properties from those of pure PD. Data for the lower heating value (LHV), density and viscosity were obtained from laboratory analysis. These data were merged with the physical and thermodynamic conditions of the diesel engine of interest to evaluate the dynamic behaviour of the fuel jet in 360° of crank rotation namely, the compression stroke, and the power stroke including the injection process. Engine operational conditions were calculated using a diesel dual thermodynamic cycle taking into account fuel injection adjustment at three different speeds, namely, idle speed, maximum torque speed and rated power speed.The results showed that fuel jet characteristics vary with SUCO content in the fuel blend. Two ranges of SUCO content in the blends were distinguished, 0 -80% SUCO content and 80 -100% SUCO content. Both showed a constant rate of change of jet characters per 10% increase in SUCO content in the fuel blend. Lower rates of change of fuel characters were observed at 0-80% SUCO content. The higher the temperature, the lower the rate of change of fuel jet characteristics.

Analysis of diesel engine injector nozzle spray characteristics fueled with residual fuel oil

“…Increase in the spray cone reduces the penetration length. The cone angle was determined from the processed image of the spray and result from the equation used by [ 15 ]. The transfer function block as shown in Figure 7 was developed and used to generate code blocks in MATLAB which was run in Simulink to validate the experimental result.…”

“…SMD characterizes fuel atomization and ensures even distribution of the droplets in the injection process hence, determining the combustion range and pollutant exhaust emissions. Due to the inadequacy of the Schlieren technique in determining microscopic spray parameters, the equation established by Dizayi et al [ 15 ] was used to generate a Simulink code block in MATLAB as seen in Figure 13 to validate the experimental result. Where; , and = density of injected fluid and density of working gas fluid respectively.…”

“…The heating time needed to raise the temperature of the fuel to 48 C in the first heating stage is expressed in Eq. (15).…”

Prediction of impinging spray penetration and cone angle under different injection and ambient conditions by means of CFD and ANNs

“…Indeed, ambient temperature brings about small differences in density, viscosity and surface tension of injected fuels. Therefore, due to these small differences, remarkable difference on spray behavior will happen [44,45].…”

Effects of Heavy Fuel Oil Blend with Ethanol, n-Butanol or Methanol Bioalcohols on the Spray Characteristics

“…Finally, one can conclude that non-reacting spray characteristics are significantly affected by the injected fuel properties. Indeed, small differences in density, viscosity, and surface tension of the injected fuels can have major effects on the injected spray (Lefebvre 1989;Dizayi et al 2014). In other words, based on Lefebvre's (1989) study, viscosity and surface tension increase lead to higher spray penetration length and spray cone angle.…”