2.4 Fuel impact on diesel engines
The main objective of this section is to make
you acquainted with the relevance of fuel
parameters on,Abnormal ignition and
combustion,Wear,piston ring collapse and
breakage,Gas leakage,Ignition,combustion
and exhaust gas emission,Engine damages and
operational problems,Prevention of engine
damages with off spec,fuels and to recognize
their impact on the operation of marine diesel
engines.
? Abnormal ignition and combustion
2.4 Fuel impact on diesel engines
– Density,Density of a fuel oil decreases with rise in
temperature,The density has no direct importance for
the engine operating condition,but a high density
indicates that a fuel contains heavy or complex
hydrocarbons,High density can lead to slow
combustion and an increased degree of late
combustion,Slow combustion and late combustion will
have the following effects on the engine,Increased
metal temperature (increased thermal loads),Reduced
efficiency and thereby,increased specific fuel
consumption,increased exhaust temperature,
increased tendency for fouling,increased wear due to
thermal overload of the oil film on the liners.
2.4 Fuel impact on diesel engines
– Viscometers,regulators,Viscosity is a measure of
resistance to flow and is not an indication of the fuel
quality,Automatic viscosity controllers are
recommended in order to obtain constant viscosity
regardless of engine fuel demands,It is of great
importance to know the viscosity in order to select
the right temperature,to ensure that the fuel oil
viscosity is correct for atomization,The viscosity
meter is installed in the fuel supply line,to ensure
the right viscosity regardless of the consumption
rate,
2.4 Fuel impact on diesel engines
Viscosity depends on the fuel oil temperature,
(decreases with increasing temperature),but
will not change by fuel treatment,Due to the
cracking process,heavy fuel oil viscosity can
not be used to indicate oil quality,Fuel oil
viscosity is important for determining the
preheat temperature in order to reach the
correct viscosity at the injection pumps,
Typical values at injection is in the range 10
to 20 cst,
Table 2.4 Viscosity/temperature relations
2.4 Fuel impact on diesel engines
? Correct viscosity at the fuel injection pumps
gives optimal injection and combustion,Too
high or too low preheating temperature causes
problems to fuel injection equipment and
mechanical loads,It also affects the combustion
process,With high density fuel it is advisable to
use a high viscosity fuel,(Lower CCAI)
? Inadequate preheating will influence
combustion,cause increased cylinder wear and
may result in too high injection pressure,
leading to excessive stress in the fuel oil system.
2.4 Fuel impact on diesel engines
– Ignition properties,Poor ignition causes increased
ignition delay,Fuel is injected into the cylinder and
begins to vaporize and mix with the surrounding air,
After a short delay,the heat of compression causes
spontaneous ignition to occur,and accumulated
vapour formed during the internal injection phase is
vigorously burned,This delay between the
commencement of injection of the fuel droplets and
the moment of spontaneous ignition of the fuel
vapour is known as the ignition delay period,and
occurs in all diesel engines.
2.4 Fuel impact on diesel engines
? Following ignition is a period of controlled
combustion,which maintains pressure on the
piston,and is characterized initially by the
steady and even combustion for the fuel after
injection has terminated,During the ignition
phase,the pressure in the engine cylinder rises
rapidly and considerable stresses are imposed
on the piston,It is desirable to keep the rate of
pressure rise as low as possible,and this is
achieved by ensuring that the minimum
quantity of fuel is present in the cylinder prior
to the ignition.
2.4 Fuel impact on diesel engines
? With long ignition delay,a relatively large
amount of fuel droplets will have been injected,
and thus vaporized in the cylinder by the time
ignition occurs,On igniting,this large amount
of accumulated vapour will combust almost
explosively,leading to sudden and abnormal
high rate of pressure rise and high cylinder
pressure,beyond that for which engine was
designed or can perhaps tolerate,Long
ignition delay leads to a sudden pressure rise
in the cylinder.
2.4 Fuel impact on diesel engines
? Damages,Typical damage that can occur
when using fuels with poor ignition properties
are,Deterioration in piston ring operation and
broken rings,Leakage of gas past the rings
(blow by),Deterioration in cylinder lubricant
oil film and extreme wear and potential
damage to the cylinder liner,Cracks and
erosion damage to pistons,It is also likely that
increased mechanical load over long time can
cause damage to bearings.
2.4 Fuel impact on diesel engines
? Water,Water is undesirable in fuel
when it is injected into the cylinders,In
practice it is impossible to be entirely
certain that the fuel is completely free of
water,Sea water can lead to problems,
because the sodium will get into the
cylinder,Fresh water should not lead to
serious problems if it is evenly
distributed in the fuel oil,
2.4 Fuel impact on diesel engines
?Problems due to high water content can be:
? Steam formation,cavitations and erosion of
the components in the fuel injection system.
? Unstable and incomplete combustion.
? Salt water will lead to fouling and high
temperature corrosion in the cylinder units
and on the turbocharger,
2.4 Fuel impact on diesel engines
?Ash,Ash content indicates the presence of
solid particles,These can include:
? Solid impurities in particle form (sand,rust,
remains of catalyst from cracking process etc.)
? Metal salts (vanadium,sodium etc.)
? Other inorganic impurities
Ash content above 0.1% is considered high in
fuel as bunkered,With high ash content it is
important to be careful with pre-treatment.
2.4 Fuel impact on diesel engines
?Wear due to particles can cause the following
types of damage:
? Wear of piston and liner in the high pressure
fuel pumps,low rate of pressure increase in
the pumps
? Scoring of pump plungers and barrels
? Wear of injector needles and guides and poor
performance of injector nozzles
? Increased wear of cylinder liners,piston
rings and grooves
? Loss of piston ring performance and possible
ring breakage and leakage(blow by)
2.4 Fuel impact on diesel engines
? Liner wear,Abrasive particles cause most
wear in the upper part of the cylinder liner,
High wear of injection pumps can make it
impossible to run on distillates due to the fact
that pressure built up will be too low for such
low viscosity fuel oil,This can result in the
needle not lifting from the nozzle seat,and no
injection occurring,Aluminum and silicon
content indicate the presence of catalytically
cracked heavy cycle oil,This fraction of oil
will considerably reduce the ignition quality.
2.4 Fuel impact on diesel engines
? Damage,The combined result of
catalytic impurities and poor ignition
quality can result in serious damage
such as,Piston ring collapse,
Extensive gas leakage,Extreme wear
and crack formation,Reduced piston
ring function can also occur,due to
extensive fouling as mentioned before,
2.4 Fuel impact on diesel engines
? High temperature corrosion,Vanadium and
sodium in the fuel during combustion can
cause high temperature corrosion if they are
deposited or sticking on/to metal surfaces,In
particular,the exhaust valves,piston crowns
and turbo-chargers are exposed to this type of
corrosion for trunk engines,Exhaust gas
temperature of 530 is especially critical,A
ratio of sodium to vanadium of 1:3 is
particularly undesirable,
2.4 Fuel impact on diesel engines
? Low temperature corrosion,Sulphur in the fuel oil will
not normally lead to operating problems,During
normal operation the sulphuric acid produced by the
combustion is neutralized by the use of alkaline
lubricating oils,both for cylinder lubrication and
system oils,To avoid sulphur corrosion it is important
to use cylinder oil with the right TBN value,For the
most common heavy fuels a TBN value of 70 will be
suitable,With very low sulphur content it might be
necessary to reconsider this,Low temperature
corrosion can occur on the nozzle tips of fuel valves or
valve stems.
2.4 Fuel impact on diesel engines
? Fouling,Operating diesel engines on
heavy fuel will always produce fouling
in the cylinder,Impurities in the fuel
which produce ash can lead to fouling,
Low ash content will not normally lead
to sufficient fouling to cause a problem,
Operating on heavy fuels at low load
over prolonged periods will lead to
increased fouling.
2.4 Fuel impact on diesel engines
? Fuel impact on diesel engines Prevention of
engine damages or minimizing risk of same
when running on off spec,fuel,For operation
on fuels with poor ignition quality,increase in
pre-injection angle has little effect on ignition
time,This is because the ability of this type of
fuel to ignite is strongly dependent on pressure
and temperature of the charge in the cylinder,
For an earlier injection,the cylinder charge
will have a lower pressure and temperature,
which can result in a considerable increase in
the length of ignition delay.
2.4 Fuel impact on diesel engines
? Increase of process temperature The most
effective method for counteracting a long
ignition delay is to increase the temperature of
the charge air,This can be done by increasing
the cooling water/oil temperature and
increasing the scavenge air temperature in the
receiver,The best method to reduce a long
delay is to increase the scavenge air
temperature,An increase in engine
temperature at part load can lead to reduced
fouling sand less low temperature corrosion,
2.4 Fuel impact on diesel engines
?, Rough running”Increased ignition delay
will often be observed by the engineer as rough
running,This is due to the increased pressure
variations in the cylinder caused by the
increased ignition delay,It leads to higher
mechanical load on piston rings and other
components in the system,It is possible to
reduce the mechanical stresses by increasing
the engine load,The cylinder pressure and
temperature will increase and the result will be
less ignition delay,The engine will run more
smoothly,
2.4 Fuel impact on diesel engines
?, Rough running” breakdowns Some
breakdowns,particularly those connected
with the cylinder unit indicate that it is
specially important to keep the piston rings
and the piston grooves in the best condition,
This,together with not allowing too much
liner wear,will reduce the likelihood of piston
ring failure,when using fuel oils with poor
ignition quality,
2.4 Fuel impact on diesel engines
?Exhaust gas emission:
? IMO’s Air Pollution Annex to MARPOL aims to
regulate exhaust gas emission limits for oxides of
nitrogen (NOX) and sulphur (SOX),A step-by-step
solution is planned for the introduction of NOX limits,
the permissible values being reduced further at a
later stage.
? The world merchant fleet annually burns over 100
million tones of fuel,Propulsion diesel engines usually
operate on heavy fuel oils whose composition with
respect to emission-related constituents (sulphur,for
example) vary widely,
2.4 Fuel impact on diesel engines
? Designing engines with optimized exhaust gas
emission behavior is therefore difficult,This is
one of the reasons why shipping is less
environment friendly than other transport
modes in terms of sulphur,soot and particle
discharge per tonne-kilometre.
? Tightening controls are expected to make the
emissions performance of an engine even more
important in the sales decision,than its fuel
economy,by the end of the century.
2.4 Fuel impact on diesel engines
? New projects focuses on propulsion plants and aims to
reduce drastically the visible emission of soot and
particles in the exhaust gas,under all engine operating
conditions,including non-steady state running.
? A further goal is to decrease the level of NOX emitted
by large engines by 50% through internal measures
and by 95% through after treatment by catalytic
reactors,These results are sought without increasing
fuel consumption,an ambitious target since high
thermal efficiency (and hence fuel economy) is not
naturally compatible with clean exhaust emission,
2.4 Fuel impact on diesel engines
?A number of routes are available which can be applied
singly of in combination to reduce noxious emissions:
1,Fuel quality,using fuel with a low sulphur content,
diesel oil with low exhaust gas emissions (ash,metals,
and aromatic hydrocarbons),fuel/water emulsions or
alternative fuels.
2,Internal engine measures,charge air cooling,water
injection,delaying the start of fuel injection,optimizing
the configuration of the combustion chamber or
injection system,exhaust gas recirculation and non-
catalytic internal NOX reduction.
2.4 Fuel impact on diesel engines
? 3,Exhaust gas treatment,particle filter,soot
separator,and exhaust gas scrubber,
reduction-type catalytic reactor,and
oxidation-type catalytic reactor.
Improved thermal efficiency through high
efficiency combustion and a so-called
escharotics system for automatic controlling
fuel injection and valve timing is also in
progress,Although the question of emission is
not most important here.
2.4 Fuel impact on diesel engines
?Fuel Parameters:
Density Density alone will have no impact on
the engine.
Viscosity Viscosity alone will have no impact
on the engine
Carbon residue micro Carbon residue micro
may lead to piston groove fouling,exhaust
turbine erosion and deposits.
Ash Ash may lead to cylinder wear,piston
wear,piston groove fouling,exhaust turbine
erosion and deposits,
2.4 Fuel impact on diesel engines
Water Water may lead to ignition delay,
combustion problems.
Sulphur Sulphur may lead to corrosive wear,
cylinder wear,piston ring wear,piston groove
wear.
Vanadium Vanadium may lead to exhaust valve
corrosion,exhaust turbine fouling.
Sodium Sodium may lead to deposits and wear of
injectors,piston groove wear and fouling,exhaust
valve corrosion,exhaust turbine fouling.
2.4 Fuel impact on diesel engines
Aluminum/silicon Aluminum/silicon may lead
to injection pump wear,fuel valve wear,
cylinder wear,piston ring wear,piston ring
wear,exhaust turbine erosion and deposits.
High CCAI High CCAI indicate ignition delay
and high pressure variations in the combustion
chamber.
Incompatibility Incompatibility may lead to
wear and deposits in the injector and the fuel
system in general.
Asphaltenes Asphaltenes may lead to problems
in the combustion process,
End of chapter 2
The main objective of this section is to make
you acquainted with the relevance of fuel
parameters on,Abnormal ignition and
combustion,Wear,piston ring collapse and
breakage,Gas leakage,Ignition,combustion
and exhaust gas emission,Engine damages and
operational problems,Prevention of engine
damages with off spec,fuels and to recognize
their impact on the operation of marine diesel
engines.
? Abnormal ignition and combustion
2.4 Fuel impact on diesel engines
– Density,Density of a fuel oil decreases with rise in
temperature,The density has no direct importance for
the engine operating condition,but a high density
indicates that a fuel contains heavy or complex
hydrocarbons,High density can lead to slow
combustion and an increased degree of late
combustion,Slow combustion and late combustion will
have the following effects on the engine,Increased
metal temperature (increased thermal loads),Reduced
efficiency and thereby,increased specific fuel
consumption,increased exhaust temperature,
increased tendency for fouling,increased wear due to
thermal overload of the oil film on the liners.
2.4 Fuel impact on diesel engines
– Viscometers,regulators,Viscosity is a measure of
resistance to flow and is not an indication of the fuel
quality,Automatic viscosity controllers are
recommended in order to obtain constant viscosity
regardless of engine fuel demands,It is of great
importance to know the viscosity in order to select
the right temperature,to ensure that the fuel oil
viscosity is correct for atomization,The viscosity
meter is installed in the fuel supply line,to ensure
the right viscosity regardless of the consumption
rate,
2.4 Fuel impact on diesel engines
Viscosity depends on the fuel oil temperature,
(decreases with increasing temperature),but
will not change by fuel treatment,Due to the
cracking process,heavy fuel oil viscosity can
not be used to indicate oil quality,Fuel oil
viscosity is important for determining the
preheat temperature in order to reach the
correct viscosity at the injection pumps,
Typical values at injection is in the range 10
to 20 cst,
Table 2.4 Viscosity/temperature relations
2.4 Fuel impact on diesel engines
? Correct viscosity at the fuel injection pumps
gives optimal injection and combustion,Too
high or too low preheating temperature causes
problems to fuel injection equipment and
mechanical loads,It also affects the combustion
process,With high density fuel it is advisable to
use a high viscosity fuel,(Lower CCAI)
? Inadequate preheating will influence
combustion,cause increased cylinder wear and
may result in too high injection pressure,
leading to excessive stress in the fuel oil system.
2.4 Fuel impact on diesel engines
– Ignition properties,Poor ignition causes increased
ignition delay,Fuel is injected into the cylinder and
begins to vaporize and mix with the surrounding air,
After a short delay,the heat of compression causes
spontaneous ignition to occur,and accumulated
vapour formed during the internal injection phase is
vigorously burned,This delay between the
commencement of injection of the fuel droplets and
the moment of spontaneous ignition of the fuel
vapour is known as the ignition delay period,and
occurs in all diesel engines.
2.4 Fuel impact on diesel engines
? Following ignition is a period of controlled
combustion,which maintains pressure on the
piston,and is characterized initially by the
steady and even combustion for the fuel after
injection has terminated,During the ignition
phase,the pressure in the engine cylinder rises
rapidly and considerable stresses are imposed
on the piston,It is desirable to keep the rate of
pressure rise as low as possible,and this is
achieved by ensuring that the minimum
quantity of fuel is present in the cylinder prior
to the ignition.
2.4 Fuel impact on diesel engines
? With long ignition delay,a relatively large
amount of fuel droplets will have been injected,
and thus vaporized in the cylinder by the time
ignition occurs,On igniting,this large amount
of accumulated vapour will combust almost
explosively,leading to sudden and abnormal
high rate of pressure rise and high cylinder
pressure,beyond that for which engine was
designed or can perhaps tolerate,Long
ignition delay leads to a sudden pressure rise
in the cylinder.
2.4 Fuel impact on diesel engines
? Damages,Typical damage that can occur
when using fuels with poor ignition properties
are,Deterioration in piston ring operation and
broken rings,Leakage of gas past the rings
(blow by),Deterioration in cylinder lubricant
oil film and extreme wear and potential
damage to the cylinder liner,Cracks and
erosion damage to pistons,It is also likely that
increased mechanical load over long time can
cause damage to bearings.
2.4 Fuel impact on diesel engines
? Water,Water is undesirable in fuel
when it is injected into the cylinders,In
practice it is impossible to be entirely
certain that the fuel is completely free of
water,Sea water can lead to problems,
because the sodium will get into the
cylinder,Fresh water should not lead to
serious problems if it is evenly
distributed in the fuel oil,
2.4 Fuel impact on diesel engines
?Problems due to high water content can be:
? Steam formation,cavitations and erosion of
the components in the fuel injection system.
? Unstable and incomplete combustion.
? Salt water will lead to fouling and high
temperature corrosion in the cylinder units
and on the turbocharger,
2.4 Fuel impact on diesel engines
?Ash,Ash content indicates the presence of
solid particles,These can include:
? Solid impurities in particle form (sand,rust,
remains of catalyst from cracking process etc.)
? Metal salts (vanadium,sodium etc.)
? Other inorganic impurities
Ash content above 0.1% is considered high in
fuel as bunkered,With high ash content it is
important to be careful with pre-treatment.
2.4 Fuel impact on diesel engines
?Wear due to particles can cause the following
types of damage:
? Wear of piston and liner in the high pressure
fuel pumps,low rate of pressure increase in
the pumps
? Scoring of pump plungers and barrels
? Wear of injector needles and guides and poor
performance of injector nozzles
? Increased wear of cylinder liners,piston
rings and grooves
? Loss of piston ring performance and possible
ring breakage and leakage(blow by)
2.4 Fuel impact on diesel engines
? Liner wear,Abrasive particles cause most
wear in the upper part of the cylinder liner,
High wear of injection pumps can make it
impossible to run on distillates due to the fact
that pressure built up will be too low for such
low viscosity fuel oil,This can result in the
needle not lifting from the nozzle seat,and no
injection occurring,Aluminum and silicon
content indicate the presence of catalytically
cracked heavy cycle oil,This fraction of oil
will considerably reduce the ignition quality.
2.4 Fuel impact on diesel engines
? Damage,The combined result of
catalytic impurities and poor ignition
quality can result in serious damage
such as,Piston ring collapse,
Extensive gas leakage,Extreme wear
and crack formation,Reduced piston
ring function can also occur,due to
extensive fouling as mentioned before,
2.4 Fuel impact on diesel engines
? High temperature corrosion,Vanadium and
sodium in the fuel during combustion can
cause high temperature corrosion if they are
deposited or sticking on/to metal surfaces,In
particular,the exhaust valves,piston crowns
and turbo-chargers are exposed to this type of
corrosion for trunk engines,Exhaust gas
temperature of 530 is especially critical,A
ratio of sodium to vanadium of 1:3 is
particularly undesirable,
2.4 Fuel impact on diesel engines
? Low temperature corrosion,Sulphur in the fuel oil will
not normally lead to operating problems,During
normal operation the sulphuric acid produced by the
combustion is neutralized by the use of alkaline
lubricating oils,both for cylinder lubrication and
system oils,To avoid sulphur corrosion it is important
to use cylinder oil with the right TBN value,For the
most common heavy fuels a TBN value of 70 will be
suitable,With very low sulphur content it might be
necessary to reconsider this,Low temperature
corrosion can occur on the nozzle tips of fuel valves or
valve stems.
2.4 Fuel impact on diesel engines
? Fouling,Operating diesel engines on
heavy fuel will always produce fouling
in the cylinder,Impurities in the fuel
which produce ash can lead to fouling,
Low ash content will not normally lead
to sufficient fouling to cause a problem,
Operating on heavy fuels at low load
over prolonged periods will lead to
increased fouling.
2.4 Fuel impact on diesel engines
? Fuel impact on diesel engines Prevention of
engine damages or minimizing risk of same
when running on off spec,fuel,For operation
on fuels with poor ignition quality,increase in
pre-injection angle has little effect on ignition
time,This is because the ability of this type of
fuel to ignite is strongly dependent on pressure
and temperature of the charge in the cylinder,
For an earlier injection,the cylinder charge
will have a lower pressure and temperature,
which can result in a considerable increase in
the length of ignition delay.
2.4 Fuel impact on diesel engines
? Increase of process temperature The most
effective method for counteracting a long
ignition delay is to increase the temperature of
the charge air,This can be done by increasing
the cooling water/oil temperature and
increasing the scavenge air temperature in the
receiver,The best method to reduce a long
delay is to increase the scavenge air
temperature,An increase in engine
temperature at part load can lead to reduced
fouling sand less low temperature corrosion,
2.4 Fuel impact on diesel engines
?, Rough running”Increased ignition delay
will often be observed by the engineer as rough
running,This is due to the increased pressure
variations in the cylinder caused by the
increased ignition delay,It leads to higher
mechanical load on piston rings and other
components in the system,It is possible to
reduce the mechanical stresses by increasing
the engine load,The cylinder pressure and
temperature will increase and the result will be
less ignition delay,The engine will run more
smoothly,
2.4 Fuel impact on diesel engines
?, Rough running” breakdowns Some
breakdowns,particularly those connected
with the cylinder unit indicate that it is
specially important to keep the piston rings
and the piston grooves in the best condition,
This,together with not allowing too much
liner wear,will reduce the likelihood of piston
ring failure,when using fuel oils with poor
ignition quality,
2.4 Fuel impact on diesel engines
?Exhaust gas emission:
? IMO’s Air Pollution Annex to MARPOL aims to
regulate exhaust gas emission limits for oxides of
nitrogen (NOX) and sulphur (SOX),A step-by-step
solution is planned for the introduction of NOX limits,
the permissible values being reduced further at a
later stage.
? The world merchant fleet annually burns over 100
million tones of fuel,Propulsion diesel engines usually
operate on heavy fuel oils whose composition with
respect to emission-related constituents (sulphur,for
example) vary widely,
2.4 Fuel impact on diesel engines
? Designing engines with optimized exhaust gas
emission behavior is therefore difficult,This is
one of the reasons why shipping is less
environment friendly than other transport
modes in terms of sulphur,soot and particle
discharge per tonne-kilometre.
? Tightening controls are expected to make the
emissions performance of an engine even more
important in the sales decision,than its fuel
economy,by the end of the century.
2.4 Fuel impact on diesel engines
? New projects focuses on propulsion plants and aims to
reduce drastically the visible emission of soot and
particles in the exhaust gas,under all engine operating
conditions,including non-steady state running.
? A further goal is to decrease the level of NOX emitted
by large engines by 50% through internal measures
and by 95% through after treatment by catalytic
reactors,These results are sought without increasing
fuel consumption,an ambitious target since high
thermal efficiency (and hence fuel economy) is not
naturally compatible with clean exhaust emission,
2.4 Fuel impact on diesel engines
?A number of routes are available which can be applied
singly of in combination to reduce noxious emissions:
1,Fuel quality,using fuel with a low sulphur content,
diesel oil with low exhaust gas emissions (ash,metals,
and aromatic hydrocarbons),fuel/water emulsions or
alternative fuels.
2,Internal engine measures,charge air cooling,water
injection,delaying the start of fuel injection,optimizing
the configuration of the combustion chamber or
injection system,exhaust gas recirculation and non-
catalytic internal NOX reduction.
2.4 Fuel impact on diesel engines
? 3,Exhaust gas treatment,particle filter,soot
separator,and exhaust gas scrubber,
reduction-type catalytic reactor,and
oxidation-type catalytic reactor.
Improved thermal efficiency through high
efficiency combustion and a so-called
escharotics system for automatic controlling
fuel injection and valve timing is also in
progress,Although the question of emission is
not most important here.
2.4 Fuel impact on diesel engines
?Fuel Parameters:
Density Density alone will have no impact on
the engine.
Viscosity Viscosity alone will have no impact
on the engine
Carbon residue micro Carbon residue micro
may lead to piston groove fouling,exhaust
turbine erosion and deposits.
Ash Ash may lead to cylinder wear,piston
wear,piston groove fouling,exhaust turbine
erosion and deposits,
2.4 Fuel impact on diesel engines
Water Water may lead to ignition delay,
combustion problems.
Sulphur Sulphur may lead to corrosive wear,
cylinder wear,piston ring wear,piston groove
wear.
Vanadium Vanadium may lead to exhaust valve
corrosion,exhaust turbine fouling.
Sodium Sodium may lead to deposits and wear of
injectors,piston groove wear and fouling,exhaust
valve corrosion,exhaust turbine fouling.
2.4 Fuel impact on diesel engines
Aluminum/silicon Aluminum/silicon may lead
to injection pump wear,fuel valve wear,
cylinder wear,piston ring wear,piston ring
wear,exhaust turbine erosion and deposits.
High CCAI High CCAI indicate ignition delay
and high pressure variations in the combustion
chamber.
Incompatibility Incompatibility may lead to
wear and deposits in the injector and the fuel
system in general.
Asphaltenes Asphaltenes may lead to problems
in the combustion process,
End of chapter 2
