Search Results

New emission regulations require innovation in the engine intake air loop. To satisfy these requirements, new architectures of cooling systems are in the process of development. These systems use valves to regulate the exhaust gas pressure and distribution in the intake cooling loop and ultimately combustion chambers. Since lower pressure is involved in the Exhaust Gas Recirculation (EGR), Water Charge Air Cooler (WCAC) or Air Charge Air Cooler (ACAC), the condensation of exhaust gas takes place and very acidic solutions are generated. In the absence of such new architecture of cooling system in service and in order to evaluate the corrosion risk that the acidic solutions from exhaust gases condensate could create in the EGR system, several tests have been proposed as representative for simulation of service conditions.

Diesel engine turbo chargers are operating and will operate at higher temperatures and pressures due to meeting increasing emissions restriction standards.

The increasing durability requirements for aluminum heat exchangers involve the use of higher levels of magnesium in the core material in order to increase the strength of its components. The challenge is to braze these aluminum alloys by the preferred CAB process. During the CAB process magnesium diffuses out, forming a Magnesium Oxide and Magnesium Fluorides and the use of conventional flux becomes ineffective for disrupting it. When wetting occurs, the brazed joint is discontinuous and the presence of leaks becomes more probable. It was found that using a modified aluminum flux that includes some cesium in its composition for aluminum controlled atmosphere-brazing process, it is possible to obtain strong brazed joints on the heat exchangers. Additionally, the inclusion of cesium in the flux makes possible to braze aluminum alloys with higher levels of magnesium providing stronger and more durable heat exchangers assemblies.