Turbocharger Cut-off System
To meet the growing demand for running large container vessels on varying loads, MAN Diesel has developed a turbocharger cut-out system that improves main-engine performance during low-load operation.
MAN Diesel’s Turbocharger Cut-Out System lowers main-engine fuel-oil consumption and improves performance during low-load operation. The system includes two, pneumatically operated cut-out valves placed at the turbine inlet and compressor outlet.
Installation of the Turbocharger Cut-out system requires little time and MAN Diesel PrimeServ reports that with the right planning, off-hire can be avoided. Installation during voyages can be carried out by a MAN PrimeServ installation team.
On engines with three turbochargers, one turbocharger cut-out enables operation at loads from 20% to 66% MCR, delivering:
• an expected SFOC reduction of 5g/kWh and a 0.25 bar increase in scavenge-air pressure at 25% power
• an expected SFOC reduction of 3g/kWh and a 0.52 bar increase in scavenge air pressure at 50% power
• turbine-out temperature drops of up to 30 degrees.
Engines with four turbochargers and one turbocharger cut-out enables operation at loads from 20% to 74% MCR, delivering:
• an SFOC reduction of 6g/kWh per 0.15 bar increase in scavenge-air pressure at 25% power
• an SFOC reduction of 5g/kWh per 0.41 bar increase in scavenge-air pressure at 50% power
• turbine-out temperature drop of up to 50 degrees
For engines with less than three turbochargers, MAN Diesel PrimeServ recommends a solution with variable turbine inlets.