buletinul institutului politehnic din iaşi - Universitatea Tehnică ...
buletinul institutului politehnic din iaşi - Universitatea Tehnică ...
buletinul institutului politehnic din iaşi - Universitatea Tehnică ...
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Bul. Inst. Polit. Iaşi, t. LVIII (LXII), f. 4, 2012 83<br />
Zetec 2.0 L, I4 engine fuelled with hydrogen dedicatedly (Stockhausen et al.,<br />
2002), (Tang et al., 2002).<br />
Table 1<br />
Hydrogen and gasoline properties<br />
Property Hydrogen Gasoline<br />
Molecular mass, kg/kmol 2.016 114<br />
Density, kg/m 3 0.089 750<br />
Theoretical air-fuel ratio, kg/kg comb 34.32 14.5<br />
Flame velocity in air, m/s 2.37 0.12<br />
Octane number >130 90…98<br />
Auto-ignition temperature, K 850 750<br />
Lower heating value, KJ/kg 119600 42690<br />
Minimum ignition energy, mJ 0.018 0.25<br />
Flammability limits in air, % 4…75 1…7.6<br />
Laminar burning velocity in air, m/s 2…2.3 0.37…0.43<br />
Normal boiling point temperature, K 20 310…478<br />
Stoichiometric composition in air, % 29.5 1.65<br />
Adiabatic flame temperature, K 2384 2270<br />
Although fuel cells have better efficiency than hydrogen engines, the cost<br />
of a hydrogen internal combustion engine is much less than a fuel cell and the<br />
power system of a vehicle. To use hydrogen in an internal combustion engine,<br />
some modifications have to be made but the working process is basically the<br />
same. Some difficulties should be overcome before the engines go into a<br />
common use, such as detonation, backfire and abnormal combustion (Jorach,<br />
1997). By using a suitable mathematical model the performance of a hydrogen<br />
engine can be simulated therefore it is possible to determine a beneficial<br />
working range for optimizing and predicting the engine’s performance (Jie et<br />
al., 2003).<br />
Nowadays, the development of an internal combustion engine is based on<br />
a close link between experimental engine testing and numerical simulation.<br />
Multi-dimensional and one dimensional thermo-fluid dynamic models are<br />
commonly used to optimize the engine design through the prediction of the<br />
unsteady flows in the intake and exhaust systems (Onorati et al., 2007),<br />
(Winterbone & Pearson, 2000), (Morel et al., 2003), (Montenegro et al., 2005),<br />
(Onorati et al., 2004 a), (Onorati et al., 2004 b), and of the combustion and<br />
emission formation processes in the cylinder (D’Errico et al., 2002), (D’Errico<br />
& Lucchini, 2005), (D’Errico et al., 2008).<br />
2. Processes Modelling<br />
There are many numerical simulation models used and because it is less<br />
expensive than experimental engine testing it is widely used in academic and