The effect of hydrogen addition to compressed natural gas on performance and emissions of a DI diesel engine by a numerical study

Diesel engines are the most commonly used internal-combustion engines. Due to incomplete combustion of fossil fuels, engine performance and emissions output are unsuitable. On the other hand Emissions of greenhouse gases using fossil fuels in internal-combustion engines are considered to be the main cause of climate change. Thus to find an alternative fuel to eliminate or reduce CO2 and exhaust emissions is an urgent concern worldwide. Superabundant and readily available, makes hydrogen an attractive alternative to fossil fuels. In this study, a 3-cylinder turbocharged diesel engine is converted into CNG direct injection engine and then hydrogen as a fuel enrichment added to CNG. AVL FireTM Software is used to simulate the engine at different engine speeds, injection pressure, and Air/Fuel ratios. The results confirm that adding hydrogen to CNG improves brake thermal efficiency and engine brake power, reduces brake specific fuel consumption as well as the diminution in HC and Soot but also increases the NOx. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.