Experimental Comparative Study on Performance and Emissions of E85 Adopting Different Injection Approaches in a Turbocharged PFI SI Engine

Abstract

This study examines the effects of ethanol and gasoline injection mode on the combustion performance and exhaust emissions of a twin cylinder port fuel injection (PFI) spark ignition (SI) engine. Generally, when using gasoline–ethanol blends, alcohol and gasoline are externally mixed with a specified blending ratio. In this activity, ethanol and gasoline were supplied into the intake manifold into two different ways: through two separated low pressure fuel injection systems (Dual-Fuel, DF) and in a blend (mix). The ratio between ethanol and gasoline was fixed at 0.85 by volume (E85). The initial reference conditions were set running the engine with full gasoline at the knock limited spark advance boundary, according to the standard engine calibration. Then E85 was injected and a spark timing sweep was carried out at rich, stoichiometric, and lean conditions. Engine performance and gaseous and particle exhaust emissions were measured. Adding ethanol could remove over-fueling with an increase in thermal efficiency without engine load penalties. Both ethanol and charge leaning resulted in a lowering of CO, HC, and PN emissions. DF injection promoted a faster evaporation of gasoline than in blend, shortening the combustion duration with a slight increase in THC and PN emissions compared to the mix mode.

Critical review on recent progress of ethanol fuelled flex‐fuel engine characteristics

“…In most studies, the BTE of FFE running on ethanol blends is higher, while BP and SFC are lowered with the increase of lambda. This can be ascribed to a faster burning rate, better combustion phasing, reduction in pumping, and heat losses of ethanol blends 97,99 . Similar to the performance characteristics of MAP, the torque, fuel consumption, thermal, and mechanical efficiency of FFE are improved with the increase of coolant temperature.…”

“…Similarly, the multiple injections of ethanol blends in FFE reduce CO, HC, and particulate emissions over single and dual‐fuel injection. Whereas, the opposite trend is followed for NO X and CO 2 with the benefit of improved charge quality and less wall wetting on the combustion chamber 97,102 …”

“…While considering the fuel injection mode, dual‐fuel (DF) injection is also followed in FFE, which significantly impacts the combustion characteristics with ethanol over mixed mode. The CP and HRR are higher and closer to TDC for ethanol blends with DF mode because the evaporation rate of gasoline is improved at dual‐fuel injection over manifold‐fuel injection 97 …”

“…In most cases, the HC, CO, and particulate emissions are lowered for ethanol blends in FFE with mixture enleanment due to better combustion and reduction in the quantity of fuel injected 89 . In the meantime, CO 2 emission is increased with lean mixture due to better combustion with higher availability of oxygen 97 . Also, NOx emission is lowered at lean and rich mixture conditions.…”

Effects of Compression Ratio of Bio-Fueled SI Engines on the Thermal Balance and Waste Heat Recovery Potential

“…The benefits of adding ethanol into gasoline were demonstrated in terms of reducing the engine-out emissions and increasing the efficiency. Tornatore et al [20] examined the effect of E85 injection mode on performance, gaseous and particle emissions of a turbocharged port fuel SI engine at 3000 rpm and high engine load for different air-fuel ratios. In their research, ethanol and gasoline were supplied into the intake manifold by two different ways: through two separated low-pressure fuel injection systems and in a blend.…”