Search Results

Step by step US and European legislation are defining more stringent emission limits for diesel engines. Depending on these limits for NOx and particulate emissions different emission reduction concepts including or excluding cooled exhaust gas recirculation (EGR) appear over time. Most probable cooled EGR will be the solution for US02 and, in combination with particulate traps, for many Euro4 applications. Competitive aftertreatment solutions like selective catalytic reduction (SCR) may need cooled EGR in addition to meet even tougher emission targets. Therefore cooled EGR can be assumed to be a long term task. The impacts on the power train cooling system arise from the need of high performance EGR systems. This results in increased heat rejection from the EGR cooler and increased pressure and temperature loads on the charge air cooling system.

The cooling system is designed on the basis of thermally critical operating conditions. For thermally uncritical partial-load conditions under which a vehicle normally operates during most of its service life thermal-management measures offer considerable potential for reducing the impact of the motor vehicle on the environment. At the same time they are enhancing passenger and driver safety and comfort. These objectives can be achieved by using newly developed actuators in conjunction with intelligent control systems. As part of its thermal management strategy Behr is developing new kinds of actuators, system configurations and control algorithms which permit demand-responsive control and supply of mass and heat flows.