Caterpillar ACERTs it won't need EGR.(Advanced Combustion Emissions Reduction Technology)(Brief Article)

Caterpillar Engine Division, Mossville, Ill., knows how it will meet truck diesel emission standards, at least until 2007 and, likely, beyond. And, it will do so without cooled exhaust-gas recirculation (EGR)--an emissions remedy thought to be indispensable in meeting future emissions regs.

Cat's strategy is called ACERT (for "Advanced Combustion Emissions Reduction Technology"), and the strategy is simple, at least in concept. Cat will combine an enhanced version of its HEUI (hydraulic-electronic unit injection) system, which will minimize emissions in the cylinder, with a simple oxidizing catalytic converter to polish off particulate and hydrocarbons. This type of catalyst does not require the use of low-sulfur fuel (though emissions would be lower with such fuel) and, says Cat, it has already proven effective and reliable on smaller trucks using Caterpillar 3126 engines.

Claimed advantages of the system will include efficient packaging, lower noise, and enhanced engine-brake performance. Fuel economy will be as good as with current engines, and engine ratings will remain the same. Caterpillar's David Semlow, marketing manager of the truck engine division, says, "ACERT is a customer-driven solution that is designed for the long-term."

Cat says the elimination of the engine-coolant-cooled EGR system saves a good deal of room in the engine compartment, and minimizes installation complexity and the need for new hardware, while minimizing the increase in heat rejection. Since the total amount of heat the radiator must carry away for a given power rating is likely to be only 2-3% higher than with current engines, present radiators and frontal areas should provide more than adequate cooling.

This should mean a minimal cost impact for the truck builders and end users. According to Cat's John Campbell, director, performance engine products division, "The simplicity of the system will mean that the transition from current engines to ACERT-equipped engines will be almost unnoticeable to the customer."

Cat claims the combustion system will produce much lower noise, and company engineers intend to make the most of this by fine-tuning the block design to ...