Performance-emission effect of n-butanol in Reactivity Controlled Compression Ignition regimes of biodiesel combustion

ABSTRACT

A comprehensive investigation has been undertaken to explore the effect of split injection phasing under simultaneous port fuel-injected butanol-induced reactivity phasing on the standard biodiesel combustion regimes in an existing single-cylinder diesel engine. Experiments were conducted on a four-stroke single-cylinder CI engine coupled with a manifold intake system at a constant speed of 1500 rpm. Butanol injected (0 ms, 2 ms, 3 ms, 4 ms) through the PFI system was varied along with the split injection timing (55° PISA −23° MISA CA bTDC, 45° PISA −15° MISA CA bTDC, 35° PISA −5° MISA CA bTDC) and pilot injection quantity (25%, 50%, 75%) of Mahua biodiesel. Analysis revealed that the minimum brake-specific energy consumption and the highest exergy efficiency registered were respectively 28.86% lower and 110.29% higher than baseline biodiesel operation. The emission parameters of NO_X, Soot, CO, and unburnt hydrocarbons under the induced RCCI regimes also registered a drastic 58.56%, 82.48%, 83.48%, and 97% lower footprint than baseline diesel operation at full load.

KEYWORDS:

• Biodiesel
• split injection
• butanol
• PFI
• performance-emission

Abbreviation

BSEC:	=	Equivalent Brake Specific Energy Consumption;
bTDC:	=	Before Top-Dead Centre:
B100:	=	100% Mahua Biodiesel energy share:
BDO:	=	Baseline Diesel Operation:
BES:	=	Butanol Energy Share:
CDF:	=	Conventional Dual Fuel Combustion:
CDC:	=	Conventional Diesel Combustion:
CN:	=	Cetane Number:
CO:	=	Carbon Monoxide:
CA:	=	Crank Angle:
DI:	=	Direct Injection:
EGR:	=	Exhaust Gas Recirculation:
ECU:	=	Electronic Control Unit:
HCCI:	=	Homogenous Charged Compression Ignition:
LHV:	=	Lower Heating Value:
MB:	=	Mahua biodiesel:
MISA:	=	Main Injection Start Angle:
NOX:	=	Nitrogen Oxides:
PDFC:	=	Partial dual-fuel combustion:
PFI:	=	Port Fuel Injection:
PISA:	=	Pilot Injection Start Angle:
PIFP:	=	Pilot Injection Fuel Percentage:
PM:	=	Particulate Matter:
PPCI:	=	Partially Premixed Charged Compression Ignition:
RCCI:	=	Reactivity Controlled Compression Ignition:
SOI:	=	Start of Injection:
TUHC:	=	Total Unburnt Hydrocarbons:
ULSD:	=	ultra-low-Sulphur diesel:
VCR:	=	Variable Compression Ratio.

Acknowledgements

The authors acknowledge the kind support received from the Department of Mechanical Engineering, NIT Agartala, MHRD, and the Research and Development division of Chandigarh University for providing technical support throughout the investigation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the Ministry of Education, India [SRF Scholarship].

Notes on contributors

Anindita Sengupta

Anindita Sengupta PhD Scholar in Mechanical Engineering Department of NIT Agartala, India with research interest on IC Engine paradigm, statistical analysis, and optimization.

Srijit Biswas

Srijit Biswas Formal Assistant Professor of Chandigarh University and former scholar of the Mechanical Engineering Department of NIT Agartala. Life Cycle Assessment, Total Cost of Ownership, IC Engine Calibration and Testing, Statistical Modelling & Optimization Specialist.

Rahul Banerjee

Rahul Banerjee works at NIT Agartala, India as an Assistant professor. Researcher in the field of IC Engine, statistical analysis, optimization and CFD.