A High-Efficient Combustion Concept for Direct Injection Hydrogen Internal Combustion Engines

摘要

The hydrogen fueled ICE will play a significant role as the future automotive propulsion sys-tem.When high power density and instant power availability are required the hydrogen en-ginewill be the best choice.Until now most hydrogen internal combustion engine concepts had low power density, highNox-emissions and poor full load efficiency resulting in a limited vehicle range.Unlike naturally aspirated hydrogen engine concepts using external mixture formation, hy-drogendirect injection has the potential of increasing maximum power output as well aseliminating any exhaust emission.BMW has achieved a breakthrough by successfully applying this technology onto a test en-gine.The test-results show that compared with gasoline engines an increased specific engineload can easily be achieved. Operated as a naturally aspirated engine, indicated mean effectivepressures can be increased by more than 20% over that of a comparable production gasolineengine.At full and part load operation, combustion analysis and simulations were used to optimizethe engine for hydrogen combustion.In combining internal with external mixture formation a strategy to avoid any unwanted ex-haustgas emissions and at the same time increasing engine efficiency, was successfully de-ployed.By the means of thermodynamical analysis, such as pressure curve analysis, 1-dimensionalflow simulation and 3-dimensional flow calculations the potentials a combustion concept cus-tom-engineered for hydrogen are shown and future perspectives are given.