Optimised Air Management System for Heavy Duty Hydrogen Engines

Many Indian cities are amongst the most polluted cities in the world. Transport sector is identified as one of the major contributors to air pollution. Following the global trend Government of India is also promoting Near Zero Emission fuels with zero CO2 emissions as a way forward to solve the emission problem. With it's policies like Green Hydrogen Mission GOI plans to accelerate the adoption of Hydrogen as fuel in the country. These initiatives have created a breakthrough in development of Hydrogen ICE's by the Indian OEM's. Hydrogen ICE have NOx emissions as the most prominent engine out emissions. NOx emission in Hydrogen engines are very sensitive to operating lambda where after a certain threshold lambda the emissions rise significantly. Therefore the air management system pays a very important role in the hydrogen engine performance & NOx emissions. The study evaluates the various options in turbo charging system for heavy duty Hydrogen engine. As first step 1 stage Variable Geometry turbo charger was assessed with focus to have a high low end torque. The rated power with 1 stage turbo charger was maximised by supplying cooled HP EGR only at rated speed area. The results are then compared to a 2-stage variable geometry turbo charger layout which gave a much improved engine torque characteristics with improved lambda as well as an improved altitude performance. The simulations are performed in 1D domain with GT Suite software using the validated engine simulations model from FEV. The achieved lambda for the targeted performance are then used to assess the NOx emissions for the engine in WHTC emission cycle using the Mean Value Engine Model from FEV.