Resumen
The new challenge in the reduction of CO2 emissions by heavy duty trucks is leading to a technological evolution in powertrain efficiency. Towards this objective, the EU has funded in the frame of the 7th framework program the project GASTONE: a collaborative project between several private and public companies and institutions: CRF, FTP, Continental, GENTHERM, MAGNA and U. Politécnica de Valencia, targeting the development of a new powertrain concept based on the integration of electric generation, energy recovery and storage with engine system and control strategies. The main features of this CNG engine concept are:?The energy recovery from the exhaust gases heat with a cascade approach thanks to the adoption of an advanced thermoelectric generator and a turbo-generator. ?The integration of a smart kinetic energy recovery system to substitute the alternator with a smarter electrical machine. ?The electrification of the main auxiliaries (coolant and oil pumps, auxiliary e-supercharger and air conditioning compressor). The electrification process is supported by an improvement of the performance of the CNG engine (the actual average value is about 38%): this number is expected to rise by 4% thanks to the engine control strategy improvement, by 1% due to the introduction of the water charge air cooler, by 2% from the reduction of the belt drive and gear losses, by 1% from the system strategy and management optimization and by 7% from the exhaust heat recovery (thermo-electric generator plus turbo-generator). This paper presents the details of the new powertrain concept design, the simulation tool developed to support the design and optimize the system and a cost per function tool to perform an economic analysis in the hypothesis to introduce the system in the market. The obtained benefits are expressed in terms of fuel saving for a target real driving cycle and effects related to the new devices are developed and tested. The project is in the design phase and the paper collects a first estimation of results based on the design, strategy and control improvement.