ABSTRACT
The concept of hydrogen powered internal combustion engines has seen many false dawns in recent years. But today, with the drive for zero emission powertrains and the promised development of robust fuel cell technologies, a hydrogen ICE future may well be coming to complement our future electrified world.
Issues with producing and distributing high purity hydrogen gas, and the need to realise the return on investment of existing products & capital equipment, makes a hydrogen burning ICE engine very attractive, particularly in the off highway and heavy duty sectors and in developing markets. But it is no simple conversion. To achieve an acceptable thermal efficiency, high lambda values and diesel-like peak firing pressures (PFP) are required. New combustion systems for High Pressure Direct Injection (HPDI) need to be developed, along with the associated hardware for injection and ignition strategies. Exhaust aftertreatment systems need to specified & optimised for NOx conversion, and new engine control strategies will be required.
This paper will present AVL proposals and test results in the development of H2 ICE concepts. CFD modelling results for hydrogen combustion systems will be discussed, including experience and knowledge in model parameterisation & calibration. Development status for delivery of 200+ bar PFP engines and the associated injection strategies will also be presented.
Based on extensive in-house modelling and laboratory correlation at an engine and vehicle system level, AVL will present and discuss possible H2 ICE configurations utilising parallel hybrid and waste heat recovery technologies. These will be shown to potentially offer a reduced system level H2 consumption for a number of on and off highway applications (including a typical long haul heavy duty trucks) that approach or even better fuel cell efficiency at a vehicle level.
