Showing posts with label TURBOCHARGER. Show all posts
REASON OF TURBOCHARGER DAMAGE
Diesel Engine Exhaust Turbocharger Failure
Turbochargers are among the foremost technologically advanced engine element aboard ship. impeller blades of a medium sized turbocharger often rotate at the maximum amount as 400 revolutions per second. The outer edges of the rotor blades therefore move at 1.5 times the speed of sound.
In the method, the turbocharger digests contaminated exhaust gases of up to 700 degrees centigrade. Thus, the turbocharger may be a terribly sensitive piece of high-speed machinery incessantly serving in harsh conditions and underneath extreme strain. Being on the receiving end of gas flows, turbocharger damages are typically caused by the failure of varied upstream elements.
Turbochargers are among the foremost technologically advanced engine element aboard ship. impeller blades of a medium sized turbocharger often rotate at the maximum amount as 400 revolutions per second. The outer edges of the rotor blades therefore move at 1.5 times the speed of sound.
In the method, the turbocharger digests contaminated exhaust gases of up to 700 degrees centigrade. Thus, the turbocharger may be a terribly sensitive piece of high-speed machinery incessantly serving in harsh conditions and underneath extreme strain. Being on the receiving end of gas flows, turbocharger damages are typically caused by the failure of varied upstream elements.
(1) Diesel engine inlet pressure to reduce main reasons:
(a) the compressor of the filter contamination.
(b) the impeller and vanes diffuser contamination.
(c) the supercharger turbo memory have more carbon deposit, spin resistance increase.
(d) the inter-cooler contamination, increased intake resistance.
(e) turbine exhaust not clear, this is because the pipe blockage, deformation caused by rotor speed rise is not high.
(f)supercharger outlet pressure drop suddenly, it is because of bearing damage caused by.
(2) Compressor surge main reasons:
(a) diesel engine emergency cut-off or sudden unloading (urgent throttle back).
(b) the atmospheric temperature changes cause surge. In the summer of the supercharger with test, in winter could happen surge, this is because the temperature change make working point change and cause.
(c) compressor contamination, especially vanes diffuser contamination.
(d) a engine plant 2 sets of supercharger, Shared a piece of inlet manifold, when a cylinder does not work, can lead compressor surge.
(3) Diesel engine inlet pressure is too high. Generally speaking, the inlet pressure is too high in the supercharger itself is not the problem, but by the engine of the cause, the main reasons are:
(a) the vent valve leakage.
(b) because of engine fuel injection timing inappropriate or other causes for combustion period is too long, to drive a turbine heat increase, speed up, inlet pressure increase.
(4) Produce continuous abnormal sound: this kind of failure is due to the majority of rotor and shell as a result of the collision. Due to the rotor and shell assembly clearance is small, if installation misadjustment or bearing serious damage, then hitting.
(5) The lubricating oil temperature is too high (above 105 ℃) of the main reasons:
(a) the turbine oil, gas seal damage, high temperature gas into the oil chamber.
(b) the bearing damage.
(6) Oil leakage: compressor seal close to the edge of the impeller is low pressure area, easy to produce the oil leakage fault. Main reasons are:
(a) the lubricating oil return not free. The reason has return line congestion, return line sectional area is too small, pipe joint gasket inner hole diameter less than return line; Diesel engine in the crankcase oil level higher than standard, cause oil return difficult; Diesel engine crankcase ventilation blocking or cylinder seal bad, gas expell, make the crankcase internal pressure rise.
(b) the compressor end O ring damage or material ageing and lose sealing effect.
(c) turbocharger oil inlet pressure is too high. Normal pressure is 0.25 ~ 0400000 mpa, if pressure is higher than 0.6 million mpa, from exhaust muffler nozzle will find from the supercharger turbo end leakage oil.
(d) ring not installed correctly or damage.
Tag :
TURBINE,
TURBOCHARGER
CYLINDER OIL FIRE AND TURBOCHARGER DAMAGE
EXCESS CYLINDER OIL CAUSES
TURBOCHARGER OVERSPEED
THERE ARE SEVERAL REASONS WHY MAIN ENGINE
TURBOCHARGERS BREAK DOWN, REPORTS DENZIL STUART, BUT GARD P&I CLUB IN
NORWAY RECENTLY RECEIVED A LARGE CLAIM INVOLVING ONE OF THE MORE UNUSUAL
REASONS.
THE ENGINE IN THIS CASE (6CYL OF APPROXIMATELY
16000KW) WAS EQUIPPED WITH TWO TURBOCHARGERS, STILL COMMONLY USED BY MANY
SHIPS TODAY. THE CYLINDER OIL LUBRICATOR REQUIRED MANUAL ADJUSTMENT TO EQUATE
TO A CONSUMPTION OF BETWEEN 320-3801 PER 24H. THAT MEANS THE ENGINEER HAD TO
REDUCE THE CONSUMPTION MANUALLY IF THE ENGINE LOAD WAS REDUCED TO BELOW 75% FOR
MORE THAN FOUR HOURS.
REDUCTION IN ENGINE LOAD
DURING BAD WEATHER
THE UNDERLYING CAUSE OF THE BREAKDOWNS WAS FOUND TO BE
THE SAME IN ALL CASES. DURING NORMAL RUNNING BETWEEN 75% LOAD AND MAXIMUM
CONTINUOUS RATING (MCR) EVERYTHING WAS NORMAL. THE PROBLEM STARTED DURING
PERIODS WHEN THE ENGINE-ROOM WAS UNMANNED AND THE OFFICER ON THE BRIDGE (DUE TO
BAD WEATHER) REDUCED THE ENGINE LOAD TO LESS THAN 75% WITHOUT NOTIFYING THE
DUTY ENGINEER. THE ENGINE LOAD WAS KEPT LOW (UNDER 75%) FOR A FEW HOURS AND, AS
THE WEATHER IMPROVED, IT WAS GRADUALLY RAISED TO FULL MCR.
EXCESS CYLINDER OIL IN
EXHAUST MANIFOLD RESULTING IN FIRE
WHEN THE ENGINE WAS RUNNING ON REDUCED LOAD WITHOUT
REDUCTION OF THE CYLINDER OIL CONSUMPTION, A LOT OF THE EXCESSIVE CYLINDER OIL
ENDED UP IN THE EXHAUST CHANNEL. WHEN THE OFFICER ON THE BRIDGE INCREASED THE
LOAD IT ALSO INCREASED THE HEAT IN THE EXHAUST CHANNEL WHICH, DUE TO THE
EXCESSIVE AMOUNT OF CYLINDER OIL, STARTED A FIRE IN THE EXHAUST CHAMBER. IN
ADDITION, THIS RESULTED IN EXTREME OVERSPEED ON THE TURBOCHARGERS, WHICH VERY
OFTEN ENDED UP WITH SERIOUS DAMAGE AND TOTAL BREAKDOWN. THE END RESULT IS OFTEN
COSTLY OFF-HIRE AND OTHER LOSSES FOR THE OWNER AND ALL INVOLVED. MOST INCIDENTS
OCCUR WHEN THE ENGINE-ROOM IS UNMANNED.
LESSONS
AND THE LESSON FROM THESE BREAKDOWNS? GARD SAYS THAT
IF THE ENGINE IS BUILT IN SUCH A WAY THAT EXCESSIVE AMOUNTS OF CYLINDER OIL CAN
BE PRESENT IN THE EXHAUST CHANNEL WHEN THE LOAD IS REDUCED, ALL OFFICERS AND
ENGINEERS SHOULD BE MADE FULLY AWARE OF
THE DANGERS.
FURTHER, THE SHIP MANAGEMENT TEAM MUST ENSURE THERE
ARE CLEAR INSTRUCTIONS TO OFFICERS
ON REDUCING OR INCREASING THE ENGINE LOAD WHETHER THE ENGINE-ROOM IS MANNED OR
UNMANNED AS WELL AS IN EMERGENCIES.
WHEN THE ENGINE WAS RUNNING ON REDUCED LOAD WITHOUT
REDUCTION OF THE CYLINDER OIL CONSUMPTION, A LOT OF THE EXCESSIVE CYLINDER OIL
ENDED UP IN THE EXHAUST CHANNEL. WHEN THE OFFICER ON THE BRIDGE INCREASED THE
LOAD IT ALSO INCREASED THE HEAT IN THE EXHAUST CHANNEL WHICH, DUE TO THE
EXCESSIVE AMOUNT OF CYLINDER OIL, STARTED A FIRE IN THE EXHAUST CHAMBER. IN ADDITION, THIS RESULTED IN EXTREME OVERSPEED ON THE TURBOCHARGERS, WHICH
VERY OFTEN ENDED UP WITH SERIOUS DAMAGE AND TOTAL BREAKDOWN. THE END RESULT IS
OFTEN COSTLY OFF-HIRE AND OTHER LOSSES FOR THE OWNER AND ALL.
Tag :
TURBOCHARGER