Comparative studies of ammonia combustion cycle parameters in marine compression ignition engines

Ammonia is one of the viable fuel alternatives in terms of transport decarbonisation, however, its properties are different from conventional fuels – diesel (higher ignition temperature, lower calorific value, lower flame spread rate). In addition, the use of ammonia in diesel engines has only been studied experimentally and to a limited extent. Therefore, its application to CI engines is related to complex studies and optimization of combustion cycle parameters. Based on experimental data available in the literature, in the publication are presented dual ammonia – diesel fuel heat release characteristic analysis of I. Vibe model form of factors. The relations of m-form factor and φz-ammonia combustion duration parameters for comparative fuel blends D80/A20, D60/A40, D40/A60, D20/A80 compared to D100 were evaluated. It was found that increasing energy value of ammonia in dual fuel balance above 40%, its combustion character is approaching to a two phase. The obtained results form the basis for planned rational numerical studies in order to improve energy efficiency of ammonia operated CI engines and reduce (NOx, CO, HC) emissions.