Even though hydrogen has been considered as a prospective fuel in internal combustion engines for many decades, theoretical studies on hydrogen based internal combustion engines are scarce in open literature. In the present work results obtained from theoretical studies on hydrogen fuelled, 4-stroke spark ignition (SI) engine are discussed. To study the combustion process, a single zone model is used with temperature dependent specific heats. Different correlations proposed by various authors for calculating in-cylinder heat transfer rates and frictional losses are used in the model and the results obtained using these different correlations are compared with published experimental data on a hydrogen fuelled SI engine [1]. Results are obtained in terms of operating pressures, temperatures and efficiencies. Effects of important parameters such as fuel-to-air ratio, spark advance, engine load and speed on the performance of the system are studied. Results show that the peak pressure and temperature are around 5.5 bar and 2800 K, respectively. The typical peak value of in-cylinder heat transfer coefficient is found to be around 1800 W/m2K. The brake thermal efficiency is found to be around 30%, while the exhaust temperatures are in the range of 750 – 1300K. The theoretical results obtained are found to agree reasonably well with the published experimental results of Kahraman et.al. [1].
Reference:
1.Kahraman, E., Ozcanli, S.C., Ozerdem, B., An experimental study on performance and emission characteristics of a hydrogen fuelled spark ignition engine, Int. J. of Hydrogen Energy (32) 2066-2072.