Page 35: of Maritime Reporter Magazine (May 2, 2010)

May 2010 www.marinelink.com 35

Fuel economy and emission reductions are leading agenda items for everyone who operates on the water, and with this in mind two leading propulsion manu- facturers – Wärtsilä and ABB Turbo Sys- tems – last month announced that the companies are cooperating in a joint de- velopment program for new application of two-stage turbocharging on large diesel engines.

The application of two-stage tur- bocharging technology on Wärtsilä diesel engines has been developed through close cooperation between Wärtsilä and

ABB Turbo Systems, with Wärtsilä is fo- cusing on developing advanced engine technology, which with the turbocharger, is able to reach the highest possible per- formance and become a cost-effective commercial solution for its customers.

ABB Turbo Systems is delivering the tur- bocharging technology with defined per- formance in terms of airflow, pressure ratios and efficiency.

In the new engine design, two tur- bochargers are arranged in series to gen- erate increased air pressure, airflow and a superior turbocharging effect. This re- sults in an efficiency rating of up to 76 percent.

The increased air pressure, combined with the advanced engine technology, im- proves the engine output and power den- sity by up to 10 percent. At the same time, both fuel consumption and CO2 emissions are reduced.

Further emissions reduction can be achieved with additional engine systems or by the use of exhaust gas after-treat- ment. A precise combination of fuel con- sumption levels and reductions in CO2 and NOx emissions can be selected through detailed systems configuration.

Intelligent engine control allows opti- mum operation of the advanced engine design over the whole load range, and a significant reduction in NOx emissions can be reached.

At high altitudes, 2-stage turbocharging technology guarantees the engine's oper- ational performance by compensating for the reduced air density.

Wärtsilä, ABB Turbo Systems Seek to Cut Diesel Engine Emissions

Illustration of the 2-stage turbocharger on a Wärtsilä 32 engine.

The 2-stage turbocharging technology being tested on a 20-cylinder Wärtsilä 32 engine in the laboratory in Finland.