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<strong>MAN</strong> B&W 2.08<br />
SFOC reference c<strong>on</strong>diti<strong>on</strong>s and guarantee<br />
SFOC at reference c<strong>on</strong>diti<strong>on</strong>s<br />
The SFOC <str<strong>on</strong>g>is</str<strong>on</strong>g> given in g/kWh based <strong>on</strong><br />
the reference ambient c<strong>on</strong>diti<strong>on</strong>s stated in<br />
ISO 3046-1:2002(E) and ISO 15550:2002(E):<br />
1,000 mbar ambient air pressure<br />
25 °C ambient air temperature<br />
25 °C scavenge air coolant temperature<br />
and <str<strong>on</strong>g>is</str<strong>on</strong>g> related to a fuel oil with a lower calorific<br />
value of 42,700 kJ/kg (~10,200 kcal/kg).<br />
Any d<str<strong>on</strong>g>is</str<strong>on</strong>g>crepancies between g/kWh and g/BHPh<br />
are due to the rounding of numbers for the latter.<br />
For lower calorific values and for ambient c<strong>on</strong>diti<strong>on</strong>s<br />
that are different from the ISO reference<br />
c<strong>on</strong>diti<strong>on</strong>s, the SFOC will be adjusted according<br />
to the c<strong>on</strong>versi<strong>on</strong> factors in the table below.<br />
<strong>MAN</strong> B&W ME/ME-C/ME-GI/ME-B TII-engines<br />
With<br />
pmax adjusted<br />
SFOC<br />
change<br />
Without<br />
pmax adjusted<br />
SFOC<br />
change<br />
Parameter<br />
C<strong>on</strong>diti<strong>on</strong><br />
change<br />
Scav. air coolant<br />
temperature<br />
per 10 °C r<str<strong>on</strong>g>is</str<strong>on</strong>g>e + 0.60% + 0.41%<br />
Blower inlet tem-<br />
per 10 °C r<str<strong>on</strong>g>is</str<strong>on</strong>g>e<br />
perature<br />
+ 0.20% + 0.71%<br />
Blower inlet<br />
pressure<br />
per 10 mbar<br />
r<str<strong>on</strong>g>is</str<strong>on</strong>g>e<br />
� 0.02% � 0.05%<br />
Fuel oil lower<br />
calorific value<br />
r<str<strong>on</strong>g>is</str<strong>on</strong>g>e 1%<br />
(42,700 kJ/kg)<br />
�1.00% � 1.00%<br />
With for instance 1 °C increase of the scavenge<br />
air coolant temperature, a corresp<strong>on</strong>ding 1 °C increase<br />
of the scavenge air temperature will occur<br />
and involves an SFOC increase of 0.06% if p max <str<strong>on</strong>g>is</str<strong>on</strong>g><br />
adjusted to the same value.<br />
<strong>MAN</strong> <strong>Diesel</strong><br />
SFOC guarantee<br />
Page 1 of 2<br />
The SFOC guarantee refers to the above ISO reference<br />
c<strong>on</strong>diti<strong>on</strong>s and lower calorific value and <str<strong>on</strong>g>is</str<strong>on</strong>g><br />
valid for <strong>on</strong>e running point <strong>on</strong>ly. The guaranteed<br />
running point <str<strong>on</strong>g>is</str<strong>on</strong>g> equal to the power�speed combinati<strong>on</strong><br />
in the matching point (O) = 100% SMCR<br />
but, if <strong>request</strong>ed, a running point between 85%<br />
and 100% SMCR can be selected.<br />
The SFOC guarantee <str<strong>on</strong>g>is</str<strong>on</strong>g> given with a tolerance<br />
of 5%.<br />
Recommended cooling water temperature<br />
during normal operati<strong>on</strong><br />
In general, it <str<strong>on</strong>g>is</str<strong>on</strong>g> recommended to operate the main<br />
engine with the lowest possible cooling water<br />
temperature to the air coolers, as th<str<strong>on</strong>g>is</str<strong>on</strong>g> will reduce<br />
the fuel c<strong>on</strong>sumpti<strong>on</strong> of the engine, i.e. the engine<br />
performance will be improved.<br />
However, shipyards often specify a c<strong>on</strong>stant<br />
(maximum) central cooling water temperature<br />
of 36 °C, not <strong>on</strong>ly for tropical ambient temperature<br />
c<strong>on</strong>diti<strong>on</strong>s, but also for lower ambient temperature<br />
c<strong>on</strong>diti<strong>on</strong>s. The purpose <str<strong>on</strong>g>is</str<strong>on</strong>g> probably to<br />
reduce the electric power c<strong>on</strong>sumpti<strong>on</strong> of the<br />
cooling water pumps and/or to reduce water c<strong>on</strong>densati<strong>on</strong><br />
in the air coolers.<br />
Thus, when operating with 36 °C cooling water<br />
instead of for example 10 °C (to the air coolers),<br />
the specific fuel oil c<strong>on</strong>sumpti<strong>on</strong> will increase by<br />
approx. 2 g/kWh.<br />
198 70 45-2.1