WÄRTSILÄ VASA 6L32, Инструкция по эксплуатации

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g) High carbon residue content may lead to deposit formation in the
combustion chamber and in the exhaust system, especially at low
loads.
·
Deposit formation on injection nozzle tips will disturb the fuel
atomisation and deform the fuel sprays, decreasing the com-
bustion process efficiency, and even leading to locally in-
creased thermal loads.
·
Deposits in the piston ring grooves and on the rings will hinder
the movement of the rings, causing a.o. increased blow-by of
combustion gases down to the crank case, which in turn
increases the fouling of the lubricating oil.
·
Deposits in the exhaust gas system and in the turbocharger will
disturb the gas exchange and increase the thermal load.
h) High asphaltene content may contribute to deposit formation in
the combustion chamber and in the exhaust system, especially at
low loads.
Asphaltenes are complex, highly aromatic compounds with a
high molecular weight, that usually contain sulphur, nitrogen and
oxygen, as well as metals like vanadium, nickel, and iron (see “Ash”
above). A high asphaltene content indicates that a fuel may be
difficult to ignite and that it burns slowly.
If the fuel is unstable, the asphaltenes may precipitate from the
fuel and block filters and/or cause deposits in the fuel system, as well
as excessive centrifuge sludge.
i) A low flash point (high vapour pressure) is often seen especially for
crude oils.
The low flash point will not influence the combustion, but the fuel
can be dangerous to handle and store. This is especially the case if
the pour point is high, and the fuel has to be heated due to this.
Special explosion proof equipment and separators can be used in
extreme cases.
A high vapour pressure (low flash point) can also give cavitation
and gas pockets in the fuel pipes. These can be avoided by using
an elevated pressure in the fuel handling system.
It is to be noted that some insurance companies demand the use
of fuels having a flash point higher than 60 °C.
j) The pour point tells below which temperature the fuel does not
flow, and determines how easy it will be to handle the fuel. The
whole fuel handling system, including tanks and pipes, must be
heated to a temperature at least 10 - 15 °C above the pour point.
k) Total sediment potential tells something about the fuels stability. If
the TSP is high, the danger of sediment and sludge formation in tanks
and fuel handling systems increases, as well as the probability for
filter clogging.
TSP can also be used as a check for the compatibility of two
different fuels: The two fuels are mixed, and if the TSP for the mix
remains low, the fuels are compatible.
Fuel, Lubricating Oil, Cooling Water 200549-01
02 - 10 W20/W32/W46, W46F, 32, 32LN