Diesel
generator set works at poor diesel oil
In this conditions, the
oil supply of each friction pair surface will be poor due to poor oil supply,
it will result in abnormal wear or burn. Therefore, we should ensure enough
diesel oil before start up and during the operation of the unit.
After
cold start, step on the accelerator sharply
If the accelerator is
slammed, the speed of the diesel engine will increase sharply, which will cause
some friction surfaces on the engine to wear violently due to dry friction.
Besides, the acceptance force of piston, connecting rod and crankshaft changes
greatly, which will cause severe impact and easily damages the parts.
Emergency
stop the unit with load or suddenly stop after load removal
After the diesel generator flameout, the circulation of cooling water stops, the cooling
capacity decreases sharply, and the heated parts lose cooling, which easily
causes overheating of cylinder head, cylinder sleeve, cylinder block and other
parts, resulting in cracks or the excessive expansion of the piston is stuck in
the cylinder liner.
Therefore, the diesel
genset should be unloaded before flameout, and gradually reduce the speed,
no-load operation for a few minutes.
Operate
the unit at poor water, cooling water or high temperature engine oil
The poor cooling water
of the generator set will reduce its cooling effect, and the diesel engine will
overheat due to the lack of effective cooling;
The high temperature of
the cooling water and oil will also cause the diesel engine to overheat. At
this time, the heating load of cylinder head, piston assembly and valve is
large, and its mechanical properties such as strength and toughness are sharply
reduced, which increases part deformation, reduces the fit clearance between
parts and accelerate the wear of parts. In serious cases, there will be cracks
and stuck parts.
Load
operation without warming up the engine after cold start
When diesel generator
set cold start, due to high viscosity and poor fluidity of engine oil,
resulting in insufficient engine oil supply. Due to the lack of oil and poor
lubrication, the friction surface of the machine is severely worn, and even
some troubles such as cylinder pulling and tile burning occur.
After cold start, the
engine shall be running at idle speed for 3-5 minutes, and the engine can be
operated with load when the oil temperature reaches 40 ℃ or above.
Operate
with overspeed and overload
When diesel generator
set operates under the condition of overload and overspeed, it is easy to
increase the thermal load and mechanical load of the cylinder liner, piston,
connecting rod, etc., and easy to cause cylinder pulling, tile burning and
other faults.
Operate
at low cooling water and oil temperature
When the diesel genset
is running at low temperature cooling water for a long time, the gap between
the piston and the cylinder liner is large, the phenomenon of cylinder knocking
has occurred, and vibration has occurred, which makes the cylinder liner
cavitate. The oil temperature is too low, the viscosity of the oil is large and
the fluidity is poor, and the amount of oil in the lubricating part is
insufficient, which makes the lubrication worse, increases the wear of the
friction pair, and shortens the service life of the diesel engine.
Operate
at low oil pressure
If the oil pressure is
too low, normal oil circulation and pressure lubrication will not be carried
out in the lubrication system, and sufficient oil will not be obtained at all
lubrication parts.
Therefore, pay attention
to the condition of the oil pressure gauge or the oil pressure indicator when
the Cummins generator set is running. If it is found that the oil pressure is
lower than the specified pressure, stop the unit immediately and continue
driving after troubleshooting.
Idle
operation for a long time
When the genset is
idling, the pressure of lubricating oil is low, and the cooling effect of oil
injection at the top of piston is poor, it will result in sharp increase of
wear and easy cylinder pulling.
It can also cause poor
atomization, incomplete combustion, serious carbon deposition, and sometimes
even the valve and piston ring are stuck. For this reason, some diesel
generator set operation manual clearly stipulate that the idle running time
shall not exceed 15-20min.
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