Andreas Eilemann

Plug-in Hybrid Cooling System Requirements

In a typical plug-in hybrid electric vehicle (PHEV) installation, there exist multiple, potentially separate, cooling circuits. These circuits may have individual cooling/heating requirements or they may have common aspects. Opportunities exist for combining circuits for series applications for cost, weight and efficiency benefits. However, careful consideration must be paid to the compatibility of these circuits both in terms of temperature range requirements, but also in terms of the thermal loading of the systems on the cooling circuits. This paper presents details of a cooling system for a PHEV demonstrator recently completed by MAHLE Powertrain. The opportunities for the integration of several cooling circuits, including the cabin heating, ventilation and air-conditioning (HVAC) system, to optimise the system from a cost, package-space and weight perspective are discussed. Furthermore, the opportunities for the preconditioning and operating strategies for the complete cooling/heating system, from a holistic vehicle efficiency perspective, are also briefly outlined.

Cascaded indirect integrated charge air cooling for passenger car diesel engines

Raising specific power output in a turbocharged engine with reduced displacement is a common way to achieve low fuel consumption and emission values without sacrificing driving performance. However, the combustion process, the engine and its components, and the engine peripherals are subjected to significant effects. The technological effort increases while the thermal and mechanical loads are more intense. Increasingly greater charge air pressures and the associated rising temperatures, as well as more stringent emission regulations require more efficient charge air cooling systems that allow further reductions in charge air temperature. MAHLE has recently developed and presented integrated cascaded charge air cooling in the air intake module for gasoline engines.