Browse Publications Technical Papers 2003-01-1165
2003-03-03

Exhaust Switch Without Moving Parts for Temperature Control of NOx-adsorbers 2003-01-1165

Temperature control is essential for lean NOx-catalysts due to their limited maximum working temperature and their fast aging at high temperatures. Therefore, under high load efficient cooling is necessary. On the other hand light-up has to be fast, and cooling under low load has to be small.
This can be achieved by switching the exhaust flow between an insulated tube at low temperatures and a cooling element at high loads. Conventional systems consisting of a valve with actuator are expensive and might fail during life-time operation. Therefore, a purely passive flow switch without moving parts was designed. At low exhaust velocities the exhaust gas moves through an insulated central tube, whereas at high exhaust velocities the exhaust gas flows through an outer tube which acts as a cooling element.
The switching is characterized by the relative mass flow through the two ways as a function of total mass flow and temperature. The effects of certain geometric parameters on the switching are discussed.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 16% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Using Cartridge Valves for Increasing Productivity

851592

View Details

TECHNICAL PAPER

Super-slim 2 Axes Automotive Accelerometer Using MEMS Technology

2009-01-0636

View Details

TECHNICAL PAPER

Zero Gases for Emission Monitoring - Production, Storage, Treatment and Usage

2002-01-2712

View Details

X