Combustion and emission characteristics of a common rail diesel engine fueled with reformed diesel/palm oil/gasoline blend fuels

ABSTRACT

Palm oil is the most abundant plant oil resource in the world. Through fuel reforming, properties of diesel, palm oil, and gasoline blend fuels are superior to those of diesel. With the constraint of major properties, D56Z24G20 (56% D100, 24% palm oil, and 20% gasoline by vol.) and D42Z18G40 (42% D100, 18% palm oil, and 40% gasoline by vol.) are prepared for experimental investigation and comparison with D100 (100% diesel). The combustion and emission results indicate that D56Z24G20 and D42Z18G40 release heat more concentratedly than D100 and thereby have a higher peak combustion temperature (PCT). NOx emission of D56Z24G20 and D42Z18G40 are higher than that of D100. Particle number concentrations (PNC) of D56Z24G20 and D42Z18G40 are higher than that of D100 at low and partial loads and a little lower at medium and high loads. The high PNC of D56Z24G20 and D42Z18G40 particles is mainly attributed to the high PNC of nucleation mode particles and this phenomenon can be eliminated with a 20% ratio of exhaust gas recirculation.

KEYWORDS:

• Common rail diesel engine
• Palm oil
• fuel reforming
• combustion
• emission
• ultrafine particles

Nomenclature

$c_v$	=	Constant volume specific heat
$D_p$	=	Aerodynamic diameter
$k$	=	Specific heat ratio
$m$	=	Quality of charge
$p$	=	In-cylinder pressure
$V$	=	Instantaneous cylinder volume

Abbreviation

PM, Particulate matter; CN, Cetane number; UFPs, Ultrafine particles; BMEP, Brake mean effective pressure; ID, Ignition delay; CA, Crank angle; D100, Pure diesel; D56Z24G20 56% D100, 24% palm oil and 20% gasoline by vol. D42Z18G40 42% D100, 18% palm oil and 40% gasoline by vol. LHV, Lower heating value; SOI, Start of injection; SOC, Start of combustion; EOC, End of combustion; HRR, Heat release rate; PHRR, Peak heat release rate; PCT, Peak combustion temperature; PNC, Particle number concentration; NCMP, Nucleation mode particles; AKMP, Aitken mode particles.

Highlights

1. The reformed diesel, palm oil, and gasoline blend fuels have close properties to diesel.

2. The blend fuels release heat more concentratedly than diesel.

3. The blend fuels have lower particle NCs than diesel with 20% EGR, except 0.14 MPa BMEP.

Acknowledgments

Supported by The Key Research and Development Program of Shaanxi Province (2019ZDLGY15-07); Supported by The Youth Innovation Team of Shaanxi Universities; Supported by National Engineering Laboratory for Mobile Source Emission Control Technology (NELMS2017B02).