Engineering · Diesel — Heavy Fuel
Heavy fuel oil is heated before injection mainly to:
- ARaise its flash point
- BRemove sulfur
- CIncrease its cetane number
- DLower its viscosity to the value required for proper atomization✓ Correct
Explanation
Residual fuels are very viscous when cold. Heating reduces viscosity to roughly the injector's required range (commonly stated near 10-15 cSt at the injector) so the fuel atomizes into a fine spray for complete combustion.
Authority: Modern Marine Engineer's Manual; ISO 8217 fuel grades
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