Mdo / Mgo Cooler - Man L23/30DF Project Manual

MAN Diesel & Turbo
1689458-7.3
Page 1 (3)
L28/32S, L27/38S, L23/30DF, L23/30S, L16/24S, L21/31S, L28/32DF, V28/32H,
General
Figure 1: Fuel temperature versus viscosity.
In order to ensure a satisfactory hydrodynamic oil
film between fuel injection pump plunger/barrel,
thereby avoiding fuel injection pump seizures/stick-
ing, MAN Diesel & Turbo recommends to keep a
fuel oil viscosity at minimum 2.0 cSt measured at
the engine inlet. This limit has been used over the
years with good results and gives the required
safety margin against fuel injection pump seizures.
For some MGO´s viscosities below 2.0 cSt may be
reached at temperatures above 35°C. As the fuel
temperature increases during operation, it is impos-
sible to maintain this low temperature at the engine
inlet without a MDO/MGO cooler.
In the worst case, a temperature of 60-65°C at the
engine inlet can be expected corresponding to a
viscosity far below 2.0 cSt. The consequence may
be sticking fuel injection pumps or nozzle needles.
Also most pumps in the external system (supply
pumps, circulating pumps, transfer pumps and feed
pumps for the separator) already installed in existing
vessels, need viscosities above 2.0 cSt to function
properly.
2016.03.03

MDO / MGO cooler

V28/32S, L16/24, L21/31, L23/30H, L27/38, L28/32H
We recommend that the actual pump maker is con-
tacted for advice.
Installation
MDO/MGO Cooler & Chiller
To be able to maintain the required viscosity at the
engine inlet, it is necessary to install a MDO/MGO
cooler in the fuel system (MDO/MGO cooler instal-
led just before the engine).
The advantage of installing the MDO/MGO cooler
just before the engine is that it is possible to opti-
mise the viscosity regulation at the engine inlet.
However, the viscosity may drop below 2.0 cSt at
the circulating and other pumps in the fuel system.
The MDO/MGO cooler can also be installed before
the circulating pumps. The advantage in this case is
that the viscosity regulation may be optimised for
both the engine and the circulating pumps.
It is not advisable to install the MDO/MGO cooler
just after the engine or after the Diesel oil service
tank as this will complicate viscosity control at the
engine inlet. In case the MDO/MGO cooler is instal-
of MDO/MGO Cooler
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or