Yanmar EcoDiesel
YANMAR EcoDiesel is addressing the stricter IMO TierII regulation NOx limits with improvements to combustion technologies of engine.
In general, when NOx emissions are reduced, the fuel consumption and smoke generation will increase, adversely affecting both environment and management. As a solution to this, YANMAR has employed "the ASSIGN Combustion System", which is an innovative state-of-the-art technology, and 〝the High pressure Miller Cycle System". These systems improve the fuel consumption and smoke generation in addition to reducing NOx emissions. YANMAR marine auxiliary diesel engines already comply with IMO TierII emission requirement and meet the needs of our customers.
ASSIGN combustion system
Staggered Layout Multi-Hole Nozzle
By staggering the layout and using multiple injection holes, this design achieves sufficient total injection area and improves air utilization.
Air Flow Motion
The optimally shaped air intake port generates a suitable swirl (votex flow) in the combustion chamber as well as a squish in the compression stroke. This promotes fuel / air mixing, improving combustion efficiency.
High Pressure Miller Cycle System
Miller Type Cam
Reduced Air Temperature Before Combustion → Decreasing NOx
With the miller type cam in its intake stroke, the miller cycle closes the intake valve faster than conventional combustion. By finishing the intake stroke faster, the inhaled intake expands and decreases temperature in the cylinder, and by reducing air temperature before combustion in the next compression stroke, the NOx emission is reduced.
High Pressure Ratio Turbocharger
Recovery of Pressure in the Cylinder → Improved Fuel Consumption
Only finishing the intake stroke faster decreases the amount of air charged in the cylinder, which leads to decreased pressure in the cylinder and worsens the specific fuel consumption. By increasing the intake pressure from high pressure ratio turbocharger during the short intake stroke and sending it to the cylinder, secure the amount of air charged and recover the pressure in the cylinder to restrain the deterioration of the specific fuel consumption.
Relationship between Specific Fuel Consumption and NOx Emission
