Abstract
In the next few years, front end vehicle design will have to be profoundly modified in accordance with the pedestrian crash test specifications. The height of the cooling module at the front end should be reduced in order to increase the free space requested between the top of the cooling module and the hood.
Today there are more and more heat exchangers located at the front end and vehicles are equipped with higher and higher powered engines. The engine cooling module becomes a big problem of packaging at the front end due to the reduced space available. UltimateCoolingTM system is a new engine cooling system concept allowing us to solve this packaging problem. This new system uses only one fluid, that is water (coolant), to cool all the engine fluids, that means:
- a charged air cooler (CAC) becomes a water cooled charge air cooler (WCAC),
- an A/C condenser (CDS), becomes a water cooled condenser (WCDS),
- an engine oil cooler (OC)or a transmission oil cooler or a hydraulic oil cooler (oil to air), becomes a water cooled oil cooler (WOC),
- a (FC) fuel cooler (fuel to air), becomes a water cooled fuel cooler (WFC)...
These new heat exchangers: WCAC, WCDS, WOC and WFC will be moved from the front end to the under hood. At the front end there is only one multi-temperature radiator providing high temperature and low temperature on demand. Thus the packaging problem could be solved.
UltimateCoolingTM system application on the NISSAN XTRAIL vehicle equipped with the turbo gasoline engine, leads to modify some components as below:
- a charged air cooler (CAC) located on the top of engine becomes a water charged air cooler (WCAC) installed at the same place but smaller,
- a conventional A/C condenser (CDS) at the front end, becomes a water cooled condenser (WCDS) and fitted in the engine compartment,
- an in tank transmission oil cooler (TOC) becomes an external TOC.
At the front end, the two heat exchangers, radiator and A/C condenser, have been replaced by only one multi-temperature radiator. Important packaging reduction of front end module has been obtained by - 38 %. Concerning the global system of engine cooling, packaging reduction remains important which is up to - 42%.
Will be presented in the paper:
- new coolant architecture of UltimateCoolingTM based on XTRAIL,
- new components developed: WCAC, WCDS and TOC,
- engine cooling and A/C performance tested in the climatic wind tunnel and on road.
Keywords: Radiator, Water Charge Air Cooler, Water Condenser, Coolant architecture, Electric water pump