MAN B&W 5L28/32H, Manual

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At a 50% load change the system will be activated for
about 3-8 seconds.
Fuel oil Limiting during start procedure
During the start procedure the controller is activated
as an index limiter.
Hereby heavy smoke formation is prevented during
the start and further the regulating device cannot
over-react. The fuel limiter function stops when the
engine has reached the nominal RPM.
The jet system is blocked during the starting proce-
dure.
Air consumption
Jet air consumption at sudden stepload:
Air cons. = (Nm³)
N = Cylinder number.
Example: At step load 50% the air consumption will
be as follows:
Cyl. no. 5 6 7 8 9
Nm³ 1.12 1.35 1.57 1.80 2.02
1639456-5.0
Page 1 (2)
Lambda Controller
93.44
L28/32H
B 15 11 1
Purpose
The purpose with the lambda controller is to prevent
injection of more fuel in the combustion chamber
than can be burned during a momentary load in-
crease. This is carried out by controlling the relation
between the fuel index and the charge air pressure.
Advantages
The lambda controller has the following advantages:
- Reduction of visible smoke in case of sudden
momentary load increases.
- Improved load ability.
- Less fouling of the engines exhaust gas ways.
- Limitating of fuel oil index during starting
procedure.
The above states that the working conditions are
improved under difficult circumstances and that the
maintenance expenses for an engine, working with
many and major load changes, will be reduced.
Principles for functioning
Figure 1 illustrates the controller's operation mode.
In case of a momentary load increase the regulating
device will increase the index on the injection pumps
and hereby the regulator arm (1) is turned, the switch
(2) will touch the piston arm (3) whereby the electrical
circuit will be closed.
Thus the solenoid valve (4) opens. The jet system is
activated, the turbocharger accelerates and increases
the charge air pressure, thereby pressing the piston
backwards in the lambda cylinder when the lambda
ratio is satisfactory the jet system will be de-activated.
(step load % - 25) x N
111