Methodological Aspects of Numerical Studies of Ammonia Use in Diesel Cycle

Abstract

More than 10% of emissions from the European transport sector are accounted by maritime transport sector. Due to climate change problem, to reduce the emissions of GHG in maritime transport sector one of the promising solutions is to use ammonia. However, the properties of ammonia are very different from those of petroleum-based fuel (higher auto-ignition temperature, lower calorific value, lower flame propagation speed), therefore this complicates ammonia usage in diesel cycle. This publication presents initial stage results of innovative research in Lithuania. The essential goal is to analyze the main features of ammonia combustion cycle of CI engine by evaluating its properties based on research data available in literature to simulate the combustion cycle of a dual ammonia – diesel fuel mixture, and to optimize it using the multi-zone “AVL FIRE” software mathematical model which is based on chemical kinetics principle. The change in ecological and energetic parameters compared to a diesel cycle is also determined. When using ammonia in a diesel engine, the ignition duration increases which leads to a lower cylinder pressure, temperature, and a series of environmental and efficiency parameters deterioration. Also, depending on the boundary conditions of ICE combustion cycle, one of the most harmful exhaust components nitrogen oxides NOx increase intensively in individual cases. However, one of the essential prospects of ammonia is a significant reduction of CO2. Therefore, the ongoing scientific project of Klaipeda University studies physical processes of ammonia combustion cycle in ICE to identify its rational execution conditions and to implement technological combustion cycle optimization principles for rational use in ship power plants.