The Performance of a Hydrogen-Oxygen S.I. Engine 2002-01-2688

An engine is described that operates exclusively on stoichiometric H₂-O₂ mixtures with significant amounts of excess hydrogen circulated to effect controlled combustion of excessively rich mixtures within the engine cylinder combined with exhaust water condensation and removal. A two-zone quasi-dimensional model for predicting the performance and the likelihood of the onset of knock developed earlier for CH₄-H₂-air operation has been extended suitably to predict the approximate performance of this H₂-O₂ engine arrangement. A detailed chemical kinetic scheme for the oxidation reactions of H₂-O₂ mixtures is adopted in the knock prediction of this model. A prior knowledge of the variation of the combustion period needed for this predictive model was estimated through processing corresponding data for H₂-air mixtures. The limited experimental results reported by Furuhama, et al., were used to validate the corresponding predicted values. Some aspects of the performance of such a H₂-O₂ engine were investigated and shown to be capable of knock free operation with very high work production efficiency. Moreover, the setup is equally attractive for simultaneous production of power and heat in a co-generation version where the H₂O heat evolved through cooling and condensation is usefully utilized. The feasibility of adopting other diluents such as argon in this engine was also examined and shown to be less attractive than with recirculating hydrogen.