The Effect of Hydrogen on Performance of Internal Combustion Engine Fueled by Compressed Natural Gas

The natural gas can readily serve as the replacement fuel for internal combustion engines. This work tested the SI engine when running on a hydrogen-enriched compressed natural gas (CNG) mixture. The modelling has been implemented at a range of engine speeds from 1000 to 5500 rpm with a full load, direct injection, and a spark-ignited engine with a compression ratio of 10. Engine performance influences were examined, especially regarding brake power, brake thermal efficiency (BTE), and brake specific fuel consumption (BSFC), in addition to the combustion characteristics like cylinder temperature and pressure. A Lotus Engine Simulation program was used for analyzing and modeling. The results demonstrated that the best performance and combustion characteristics were with mixtures that have increased in the H2 percentage. The results show that the brake power and BTE increased, and the BSFC decreased with the increase of hydrogen in the mixture. It was found that the brake power and BTE increased by 2% and 21% for HCNG 25, and the best reduction in BSFC was 6% for HCNG 20 compared to the CNG. It was also observed that maximum cylinder pressure (Pmax) and temperature (Tmax) increase with increasing percentage of H2 in the mixture.