Junichiro Hara

New Compact and Fuel Economy Cooling System “SLIM”

A new engine cooling system is proposed that alters sub-radiator function according to driving conditions without valves and actuators. This system enables substantial fuel consumption improvement by: (1) Simplified heat exchanger configuration located in the front end of a vehicle with only two layers instead of three, which leads to 30 % reduction in pressure drop of air flow. (2) Cooling fan power and air-conditioning compressor load reduction associated with above mentioned air flow improvement. This performance improvement mechanism of the new system called SLIM (Single Layer Integrated cooling Module) is studied in various aspects such as air pressure drop in comparison with full water-cooled condenser systems. Furthermore, by extending the concept to CAC (Charge Air Cooler) with a focus on the use of optimum heat transfer efficiency, a new 2-way CAC structure is proposed. 30 % improvement in heat exchange performance over conventional water cooled CAC is confirmed.