Improvement in Performance and Emission Characteristics of a Single Cylinder S.I. Engine Operated on Blends of CNG and Hydrogen

This paper presents the experimental results of a
single cylinder Enfield engine using an electronically controlled fuel
injection system which was developed to carry out exhaustive tests
using neat CNG, and mixtures of hydrogen in compressed natural gas
(HCNG) as 0, 5, 10, 15 and 20% by energy. Experiments were
performed at 2000 and 2400 rpm with wide open throttle and varying
the equivalence ratio. Hydrogen which has fast burning rate, when
added to compressed natural gas, enhances its flame propagation rate.
The emissions of HC, CO, decreased with increasing percentage of
hydrogen but NOx was found to increase. The results indicated a
marked improvement in the brake thermal efficiency with the
increase in percentage of hydrogen added. The improved thermal
efficiency was clearly observed to be more in lean region as
compared to rich region. This study is expected to reduce vehicular
emissions along with increase in thermal efficiency and thus help in
reduction of further environmental degradation.

• Sarbjot Singh Sandhu

• Hydrogen
• CNG
• HCNG
• Emissions.

<p>[1] J. B. Heywood. “Internal combustion engine fundamentals”. New York:
McGraw-Hill, 1988.
[2] M. Fanhua , Y. Wang, H. Liu, Y. Li, J. Wang, S. Zhao. “Experimental
study on thermal efficiency and emission characteristics of a lean burn
hydrogen enriched natural gas engine,” Int J Hydrogen Energy, vol. 32,
pp. 5067-5075, 2007.
[3] R. L. Hoekstra, P. V. Blarigan, N. Mulligan. “NOx emissions and
efficiency of hydrogen, natural gas and hydrogen/natural gas blended
fuels,” SAE paper no. 961103. Warrendale, PA: Society of Automotive
Engineers;1996.
[4] S. O. Akansu, N. Kahraman, B. Ceper. “Experimental study on spark
ignition engine fuelled by methane-hydrogen mixtures,” International
Journal of Hydrogen Energy, vol. 32, pp. 4279-4284, 2007.
[5] G. A. Karim, I. Wierzba, Y. Al-Alousi. “Methane-hydrogen mixtures as
fuels,” International Journal of Hydrogen Energy, vol. 21, no. 7, pp.
625-31, 1996.
[6] N. Kahraman, B. Ceper, S. O. Akansu, K. Aydin. “Investigation of
combustion characteristics and emissions in a spark-ignition engine
fuelled with natural gas-hydrogen blends,” International Journal of
Hydrogen Energy, vol. 34, pp. 1026-1034, 2009.
[7] F. Ma, Y. Wang, H. Liu, Y. Li, J. Wang, S. Zhao. “Experimental study
on thermal efficiency and emission characteristics of a lean burn
hydrogen enriched natural gas,” International Journal of Hydrogen
Energy, vol. 32, pp. 5067-5075, 2007.
[8] C.G. Baur, T.W. Forest. “Effect of hydrogen addition on performance of
methane-fuelled vehicles Part I: effect on S.I. engine performance,”
International Journal of Hydrogen Energy, vol. 26, pp. 55-70, 2001.
[9] J. Wang, Z Huang, Y. Fang, B. Liu, K. Zeng, H. Miao, et al.
“Combustion behaviors of a direct-injection engine operating on various
fractions of natural gas hydrogen blends,” International Journal of
Hydrogen Energy, vol.32, no.15, pp. 3555-64, 2007.
[10] M. Fanhua, Y. Wang, H. Liu, Y. Li, J. Wang, S. Zhao. “Experimental
study on thermal efficiency and emission characteristics of a lean burn
hydrogen enriched natural gas engine,” Int Journal of Hydrogen Energy,
vol. 32, pp. 5067-5075, 2007.</p>