http://www.mandiesel.com/files/news/filesof2810/p412-0503.pdf
From 2003:
Quote:
The introduction of the electronically controlled
camshaft-less low speed diesel engines, which is
now gaining momentum, is a milestone in diesel
technology that deserves a place in history like
Rudolf Diesel’s first engine in Augsburg, the
1912 motor vessel Selandia, the introduction of
turbocharging on two-stroke diesels in 1954,
and the first SCR (Selective Catalytic NOx
Reduction) systems on ships in 1989.
This paper will outline how MAN B&W takes
advantage of this new technology in its MErange
of engines by combining traditional,
proven technologies with enhanced electronic
control so as to design engines which, while
being both production-friendly and operationally
easy to handle, yet will provide all benefits to
the owner and operator of contemporary and
future software achievements. Fig. 1 shows
the first such commercial ME-C engine in
Frederikshavn, Denmark.
Camshaft-controlled diesel engines have been
the state of the art ever since the birth of
reciprocating machinery and have been refined
and developed ever since. However, a mechanical
cam is fixed once made and, in spite of
various mechanical and hydraulic add-on
devices like VIT, etc., timing control possibilities
are limited with mechanical cams. Not least
fuel injection pressure control and variation over
the load range have limitations with a camcontrolled
engine.
Therefore, the main purpose of changing to
electronic control is to ensure fuel injection
timing and rate, as well as the exhaust valve
timing and operation, exactly when and as
desired, see Fig. 2.
Especially with respect to the fuel injection rate,
the control system has been so designed that it is
possible to maintain a rather high injection
pressure also at low load, without the limitation
from the camshaft-controlled engine, where this
would result in too high pressure at high load.
Both the ‘cam angle, inclination and length’ are
electronically variable. In addition, the ME
engine features electronic control of the cylinder
lube oil feed, by having our proprietary Alpha
Lubricators integrated in the system. With the
Alpha Lubrication system, about 0.3 g/bhph cyl.
oil can be saved, compared with engines with
mechanical lubricators.
The electronic control of the engine fuel injection
and exhaust valves improves low-load operation,
engine acceleration, and give better engine
balance and load control, leading to longer times
between overhauls, also by implementation of
enhanced diagnostics systems. It will give lower
fuel consumption, lower cylinder oil consumption
and, not least, better emission characteristics,
particularly with regard to visible smoke and NOx,
see Fig. 3 for a summary.
For the ME engines, the electronic control
system has been made complete. Hence, the ME
engine features fully integrated control of all
functions like the governor, start and reversing,
fuel, exhaust and starting valves, as well as
cylinder oil feeding, as summarised in Fig. 4.
Be interesting how it works out for Koenigsegg.
