Effect of injection parameters on the hydrogen enriched dual-fuel CRDI diesel engine

ABSTRACT

To maximize the performance of the diesel engine run with alternative renewable fuels, operational parameters such as injection time (IT) and injection pressure (IP) must be fine-tuned. Meanwhile, hydrogen has come out as a one of the best alternative fuel for dual-fuel mode of operation, since it minimizes the drawback that use of biodiesel alone possesses like low calorific value, high viscosity etc. Based on the above findings, the objective of the current study is set as “to evaluate the impact of varying injection parameters on the engine characteristics of hydrogen-enriched palm fueled CRDI diesel engine.” In this research work, a hydrogen-enriched (7 lpm and 10 lpm) palm biodiesel blend (P20) with diesel fuel was used to examine how changing injection pressure (IP) and injection time (IT) affected CRDI diesel engine performance, combustion, and emission characteristics. Three different IPs (240 bar, 420 bar, and 600 bar) and ITs (23°CA bTDC, 25°CA bTDC, and 27°CA bTDC) are used at a steady speed of 1500 rpm under full load circumstances. The results showed a maximum BTE of 31.09% for P20 + 10 H₂ at 25°CA bTDC IT and 600 bar IP. Better fuel atomization is responsible for the improvement in BTE (17.94%) and BSFC (15.15%) with increased IP (600 bar). Advancement in IT (25°CA bTDC) leads to superior performance in terms of HC (32%) and CO (8.33%) emissions reduction for P20 + 10 H₂ because more time is available for optimal air-fuel mixing. However, NO_X emission increases significantly because of the rise in temperature within the cylinder with hydrogen enrichment. This can be attributed to the high calorific value of hydrogen which is almost three times to that of diesel. A maximum increase in NO_X emission of 45.65% is obtained for P20 + 10 H₂ w.r.t. diesel. With an increase in IP, ICP and HRR improve by 28.04% and 22.70%, respectively, due to improved fuel atomization, resulting in the greatest amount of fuel being burned during the pre-mixed combustion stage. It can be concluded that the 25°CA bTDC IT and 600 bar IP is the optimum condition when the engine performs at its peak.

KEYWORDS:

• In-cylinder pressure
• heat release rate
• injection pressure
• injection timing
• palm biodiesel
• CRDI engine

Nomenclature

bTDC	=	Before top death centre
BSFC	=	Brake specific fuel consumption
BTE	=	Brake thermal efficiency
CO2	=	Carbon dioxide
CO	=	Carbon monoxide
CRDI	=	Common rail direct injection
°CA	=	Degree crank angle
D100	=	Diesel
EGT	=	Exhaust gas temperature
HRR	=	Heat release rate
HC	=	Hydrocarbon
ICP	=	In-cylinder pressure
IP	=	Injection pressure
IT	=	Injection timing
LHV	=	Lower heating value
NOX	=	Nitrogen oxides
P20	=	Palm biodiesel blend (20% biodiesel + 80% diesel)
P20 + 7 H2	=	Palm biodiesel with 7 lpm hydrogen
P20 + 10 H2	=	Palm biodiesel with 10lpm hydrogen

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Shyamal Das

Dr. Shyamal Das received his Ph.D. from the National Institute of Technology Silchar, India, in the year 2023. His research interest includes internal combustion engine and alternative fuel.

Biplab Das

Dr. Biplab Das presently working as an Associate Professor in the Department of Mechanical Engineering, National Institute of Technology Silchar, India. Dr. Das completed his Ph.D. from NERIST, Itanagar, India, in the year of 2014. Later, he pursued his Post-Doctoral research at the University of Idaho, USA. He is the recipient of the prestigious Bhaskara Advanced Solar Energy (BASE) Fellowship and ‘DBT Associateship’. He has 15 years of experience in teaching/research and published more than 120 nos. of research arrticles. Presently Dr. Das has been involved in 10 nos. of sponsored projects as PI/Co-PI. He has guided 09 nos. of Ph.D., and at present, 06 Ph.D. scholars are working with him. His area of interest includes solar thermal systems, heat transfer, energy storage, and biofuel.