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This section is available on request - MAN Diesel & Turbo

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<strong>MAN</strong> B&W 3.02<br />

Exhaust Gas By�pass<br />

Extreme Ambient C<strong>on</strong>diti<strong>on</strong>s<br />

As menti<strong>on</strong>ed in Chapter , the engine power figures<br />

are valid for tropical c<strong>on</strong>diti<strong>on</strong>s at sea level:<br />

45 °C air at 000 mbar and 32 °C sea water,<br />

whereas the reference fuel c<strong>on</strong>sumpti<strong>on</strong> <str<strong>on</strong>g>is</str<strong>on</strong>g> given<br />

at ISO c<strong>on</strong>diti<strong>on</strong>s: 25 °C air at 000 mbar and<br />

25 °C charge air coolant temperature.<br />

Marine diesel engines are, however, exposed to<br />

greatly varying climatic temperatures winter and<br />

summer in arctic as well as tropical areas. These<br />

variati<strong>on</strong>s cause changes of the scavenge air<br />

pressure, the maximum combusti<strong>on</strong> pressure, the<br />

exhaust gas amount and temperatures as well as<br />

the specific fuel oil c<strong>on</strong>sumpti<strong>on</strong>.<br />

For further informati<strong>on</strong> about the possible countermeasures,<br />

please refer to our publicati<strong>on</strong> titled:<br />

Influence of Ambient Temperature C<strong>on</strong>diti<strong>on</strong>s<br />

The publicati<strong>on</strong> <str<strong>on</strong>g>is</str<strong>on</strong>g> <str<strong>on</strong>g>available</str<strong>on</strong>g> at: www.mandiesel.com<br />

under ‘Quicklinks’ → ‘Technical Papers’<br />

Arctic running c<strong>on</strong>diti<strong>on</strong><br />

For air inlet temperatures below � 0 °C the precauti<strong>on</strong>s<br />

to be taken depend very much <strong>on</strong> the<br />

operating profile of the vessel. The following alternative<br />

<str<strong>on</strong>g>is</str<strong>on</strong>g> <strong>on</strong>e of the possible countermeasures.<br />

The selecti<strong>on</strong> of countermeasures, however, must<br />

be evaluated in each individual case.<br />

<strong>MAN</strong> B&W S80MC6/C-C/ME-C7/8, K80MC-C6/ME-C6/9,<br />

S70MC6/MC-C/ME-C/ME-G7/8, L70MC-C/ME-C7/8,<br />

S60MEC6/MC-C/ME-C/ME-GI7/8, L60MC-C/ME-C7/8,<br />

S50MC6/MC-C/ME-C7/8/ME-B8/9, S46MC-C7/8, S42MC7,<br />

S40ME-B9, S35MC7, L35MC6, S26MC6<br />

<strong>MAN</strong> <strong>Diesel</strong><br />

Exhaust gas receiver with variable<br />

by�pass<br />

opti<strong>on</strong>: 4 60 8<br />

Page of 2<br />

Compensati<strong>on</strong> for low ambient temperature can<br />

be obtained by using exhaust gas by�pass system.<br />

<str<strong>on</strong>g>Th<str<strong>on</strong>g>is</str<strong>on</strong>g></str<strong>on</strong>g> arrangement ensures that <strong>on</strong>ly part of the exhaust<br />

gas goes via the turbine of the turbocharger,<br />

thus supplying less energy to the compressor<br />

which, in turn, reduces the air supply to the engine.<br />

Please note that if an exhaust gas by�pass <str<strong>on</strong>g>is</str<strong>on</strong>g> applied<br />

the turbocharger size and specificati<strong>on</strong> has<br />

to be determined by other means than stated in<br />

th<str<strong>on</strong>g>is</str<strong>on</strong>g> Chapter.<br />

Emergency Running C<strong>on</strong>diti<strong>on</strong><br />

Exhaust gas receiver with total by�pass flange<br />

and blank counterflange<br />

Opti<strong>on</strong>: 4 60 9<br />

By�pass of the total amount of exhaust gas round<br />

the turbocharger <str<strong>on</strong>g>is</str<strong>on</strong>g> <strong>on</strong>ly used for emergency running<br />

in the event of turbocharger failure <strong>on</strong> engines,<br />

see Fig. 3.02.0 .<br />

<str<strong>on</strong>g>Th<str<strong>on</strong>g>is</str<strong>on</strong>g></str<strong>on</strong>g> enables the engine to run at a higher load<br />

with <strong>on</strong>ly <strong>on</strong>e turbocharger under emergency c<strong>on</strong>diti<strong>on</strong>s.<br />

The engine’s exhaust gas receiver will in<br />

th<str<strong>on</strong>g>is</str<strong>on</strong>g> case be fitted with a by�pass flange of approximately<br />

the same diameter as the inlet pipe<br />

to the turbocharger. The emergency pipe <str<strong>on</strong>g>is</str<strong>on</strong>g> yard’s<br />

delivery.<br />

198 45 93�4.4

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