Charge air subcooling: MAHLE sets new standards in thermal management

By linking the previously independent systems for air conditioning and engine cooling, MAHLE has been able to further improve the performance of turbocharged gasoline engines.
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Fuel efficiency is increased by utilizing the surplus energy from the air conditioning system. Despite the increased power, the iCAS system does not lead to higher fuel consumption, especially thanks to the potential for recuperative preconditioning during braking phases.
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Stuttgart, September 2015 – 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.

MAHLE is a leading international supplier to the automotive industry. With its products for combustion engines and their peripherals as well as solutions for electric vehicles, the group addresses all the crucial issues related to the powertrain and air conditioning technology—from engine systems and components to filtration to thermal management. MAHLE products are fitted in every second vehicle worldwide. MAHLE components and systems are also used off the road—in stationary applications, for mobile machinery, as well in railroad, marine, and aerospace applications.

In 2014, the group generated sales of EUR 9.94 billion with around 66,000 employees. Today, MAHLE is represented in over 30 countries with 170 production locations. At 16 major development locations in Germany, Great Britain, Luxembourg, Slovenia, the USA, Brazil, Japan, China, and India, more than 5,000 development engineers and technicians are working on innovative solutions.

Further queries:
Ruben Danisch
Corporate Communications/Public Relations
Pragstraße 26–46
70376 Stuttgart
Phone: +49 711 501-12199
Fax: +49 711 501-13700


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