The 4T50ME-GI Test Engine at MAN Diesel & Turbo's ... - Sae.org

ing pressure. The design is to be all-
welded as far as practicable, with flange
connections only present for servicing
purposes as far as practicable.
The branch piping to the individual
cylinders must be flexible enough to
cope with the thermal expansion of the
engine from cold to hot states. Fig. 7
shows a principle design of the branch-
ing of the main pipe, which follows the
demands described here.
Fig. 7: Branch pipe concept
The gas-pipe system is also designed
so as to avoid excessive gas-pressure
fluctuations during operation.
Finally, gas pipes are connected to an
inert, gas-purging system.
Fuel Oil Booster Unit
Dual-fuel operation requires a fuel-oil
pressure booster, a position sensor, a
FIVA valve to control the injection of pi-
lot oil, and an ELGI valve to control the
injection of gas.
The ME fuel-oil pressure booster is a
standard ME pressure booster with a
pressure sensor added for checking
the pilot-oil injection pressure, which is
used to monitor the fuel-oil valves. The
amount of pilot-oil injected is monitored
by the position sensor.
The volume of gas injected is control-
led by the duration of control-oil delivery
from the ELGI valve. The operating me-
dium is the same control /servo oil as
used for the fuel-oil pressure booster.
Exhaust Receiver
The exhaust-gas receiver is designed to
withstand the pressure in the event of
ignition failure of one cylinder followed
by ignition of the unburned gas in the
receiver. For the S60ME-GI, this means
that the shell thickness and deep-
dished head thickness has increased
from 10 mm to 13 mm; the fix-support
Sealing oil pipes
Control oil pipes
Fig. 9: Gas control block and cylinder cover for the test rig
13 The 4T50ME-GI Test Engine at MAN Diesel & Turbo’s Copenhagen Test Centre
plate increases from 25 mm to 28 mm.
Reinforcement rings need to be adapt-
ed for the turbocharger and exhaust
pipes and the compensators have to be
able to withstand a static pressure of 20
bar at 20ºC.
Planned Tests
A gas-test rig has been produced for
operation on air in order to finalise the
design by checking the function of the
gas control-block, the gas-injection
valves and the gas window/shut down
valve. It consists of the gas control-
block, a cylinder cover with the gas-in-
jection valves, and a PLC for controlling
the test rig. Comprehensive tests on
this rig were performed during the win-
ter of 2010-2011 (see Figs. 9 and 10).
Gas injection valve
Cylinder cover
Gas control block