Performance optimization of ethanol blends in diesel model using Taguchi and grey relational approach

Area of Science:

• Internal Combustion Engines
• Sustainable Energy
• Environmental Science

Background:

• Diesel engines are vital but raise environmental and health concerns due to emissions like nitrogen oxides (NOx) and particulate matter (PM).
• Biofuels (ethanol, biodiesel) offer renewable, lower-impact alternatives but require engine optimization.
• Direct injection diesel engines in light-duty applications are a focus for improving efficiency and reducing environmental impact.

Purpose of the Study:

• To assess the impact of fuel injection pressure, ethanol-biodiesel blend percentage, and engine load on diesel engine efficiency and emissions.
• To identify optimal operating parameters for a direct injection diesel engine using biofuel blends.
• To evaluate the effectiveness of the Taguchi method and desirability function for engine optimization.

Main Methods:

• Utilized the Taguchi L9 orthogonal array to systematically vary fuel injection pressures (220-260 bar), ethanol-biodiesel fractions (10-30%), and engine loads (20-80%).
• Analyzed key performance indicators including brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE).
• Evaluated atmospheric emissions such as carbon monoxide (CO) and nitrogen oxides (NOx), alongside smoke density.

Main Results:

• Optimal parameters identified: 220 bar injection pressure, 40% ethanol-biodiesel blend, and 80% engine load.
• Achieved a 7.5% reduction in BSFC, 15% decrease in CO emissions, and 18% reduction in smoke density compared to conventional diesel.
• Maximum brake thermal efficiency (BTE) reached 32%, but NOx emissions increased by 12%, indicating a performance-emissions trade-off.

Conclusions:

• The Taguchi technique and desirability function effectively optimized diesel engine performance with biofuel blends.
• The identified optimal conditions balance improved fuel efficiency and reduced CO/smoke emissions.
• Further research is needed to mitigate the increase in NOx emissions when using higher biofuel concentrations.