Dynamic and especially demand-based control of energy flows in vehicles is one of the great challenges for increasing powertrain efficiency. iCAS, the integrated charge air subcooling system from MAHLE, impressively demonstrates today’s thermal management: innovative, interlinked, efficient.
Engine cooling circuit, low-temperature circuit, air conditioning, and new temperature control tasks such as battery conditioning or cooling of the battery’s power electronics: all of these systems must now be considered holistically. Thermal management means the systemic interlinking of various cooling circuits in the vehicle that were previously independent of one another, with the objective of improving its overall efficiency and dynamics. With the iCAS system, MAHLE has now actively incorporated air conditioning into the engine cooling or charge air cooling system for the first time. The air conditioning system thus ultimately has an indirect influence on the combustion process.
Until now, the lowest possible charge air temperature was determined by the ambient temperature. With iCAS, MAHLE has now broken through this barrier. The charge air is first precooled by a conventional charge air cooler, then routed through the iCAS heat exchanger, which in turn is cooled by a dedicated circuit coupled to the vehicle air conditioning system. The charge air can be cooled from about 120 degrees Celsius to around 10 degrees Celsius. This greatly increases the amount of charge air supplied and raises the torque of a downsizing gasoline engine at low speed by up to 19 percent.
In order to gain acceptance, however, it is crucial for iCAS to improve vehicle dynamics without negatively affecting thermal comfort or fuel consumption. With MAHLE’s systems expertise, both goals can be met and even exceeded. Due to the high thermal inertia and a sophisticated control system, thermal comfort remains constant even while the iCAS is engaged. With regard to fuel consumption, MAHLE takes advantage of both the surplus capacity of the air conditioning system and the potential for recuperative preconditioning of iCAS during braking phases—in addition to the thermodynamic advantages in combustion.
This solution underscores the pioneering role of MAHLE in the development of innovative thermal management systems and is an outstanding example of successful incorporation of competences from MAHLE’s various business segments. With iCAS, MAHLE provides its customers with an attractive opportunity to increase driving pleasure by boosting dynamics, with no penalties in terms of thermal comfort and fuel consumption.
