APPLICATION OF A SECONDARY COOLANT CIRCUIT TO CHARGE AIR AND EGR COOLING SYSTEM FOR SEGMENT C CARS AND HIGH PERFORMANCE ENGINES

摘要

The paper presents the simulation and experimental results about the application of a secondary coolant circuit at low temperature to a high performance engine on segment C Alfa Romeo car. The secondary coolant has been used to cool down the charge air at the compressor outlet and the EGR applying specific components to the system; the heat is then rejected to external ambient by means of a secondary radiator placed in front of the normal production cooling module. Both aspects of performance improvement and emission reduction have been investigated in comparison to the normal production cooling system and other innovative systems aimed to these purposes. A simulation of the complete system has been performed by means of a 1D code in order to get a first design of the indirect charge air cooler, the EGR cooler, the secondary radiator and the additional electric coolant pump. CAD model of each heat exchanger have been built up in order to allow their installation on vehicle. Tests on bench and on road have been performed in order to check the experimental behaviour of the system. Simulation and experimental results show that with such a system it is possible to get better performances from the engine and lower emissions when compared to the normal production equipment. The paper try to assess how much such a system can contribute to fulfil the future emission limits. Finally, taking into consideration as a basis the normal production cooling system, an economical analysis has been set up in order to evaluate the impacts on cost of such a solution.