Parametric Investigation of Performance of SI Engine Fuelled with Hydrogen Blended Compressed Natural Gas

The present study investigates the performance characteristics of a spark ignition (SI) engine operated on hydrogen-blended compressed natural gas (HCNG) fuel. The research aims to evaluate how varying blending ratios of hydrogen with CNG influence engine parameters such as brake thermal efficiency, brake specific fuel consumption, cylinder pressure, and exhaust gas emissions. Parametric variations including load, speed, and equivalence ratio were systematically examined to identify the optimum operating conditions. Results indicate that hydrogen enrichment significantly enhances combustion due to its high flame speed and wide flammability limits, thereby improving thermal efficiency and reducing carbon-based emissions. However, higher hydrogen proportions were observed to increase nitrogen oxide emissions due to elevated in-cylinder temperatures. The study demonstrates that an optimized blend of hydrogen in CNG can offer a cleaner and more efficient alternative fuel for SI engines, supporting the transition toward sustainable energy in the automotive sector.