Q9. Describe the following turbocharger cleaning operations.
(a) Turbine side water washing. (6)
(b) Turbine side Dry Cleaning. (5)
(c) Blower side water washing (5)
Q4. Describe the nature and the possible effects on machinery operation of deposits, which may adhere to the internal surfaces of exhaust gas turbo-blowers and explain how these deposits are removed. (16)
Q6. Following a recent turbocharger (T/C) overhaul, it has been observed that the scavenge air pressure is lower than before, and the engine power output has also been reduced.
a) State the possible causes of the problem with reasons. (5)
b) State the engine operational information that should be gathered to detect the possible causes of the problem, along with reasons for each type of information. (5)
c) State the instructions which should be issued with respect to future T/C overhauls in order to prevent similar incidents. (6)
Q4. (a) State the different types of turbo charger fitted in modern diesel engines (8)
(b) Describe the function of the (8)
(i) Nozzle ring
(ii) Labyrinth seals
(iii) Diffuser and
(iv) Inducer
Q4. With reference to a turbo-charging system of an engine:
a) State the parameters that you would check while taking over the watch. (8)
b) Action to be taken in the event of turbo-charger is observed to vibrate abnormally. (8)
Q4. (a) What are the causes of Turbocharger surging? How is it indicated to the watchkeeper? (8)
(b) What are the possible remedial action? (4)
(c) What are the reasons for excessive fouling of the turbocharger? (4)
Q1. Sketch and describe a turbocharger bearing lubrication system. State the type of bearing employed and explain the advantages and disadvantages of the lubricating system described.
Q1. (a) Explain the types of turbocharging in a marine diesel engine. (8)
(b) What are the reasons that may induce vibration on a main engine turbocharger? (8)
Q2. Describe with aid of sketches, a turbocharger bearing lubrication system, stating the type of bearing employed and explaining the advantages and disadvantages of the lubricating system described. One of the turbochargers of the main engine on the vessel aboard which you are serving as second engineer has suffered a sudden and unexpected failure. Write a letter to the ship owner/operator concerning the incident and stating the action taken in bringing the turbocharger back into service.
Q3. With reference to turbochargers:
(a) Explain the term surging, stating how it occurs, its effect on the turbocharger and how it can be avoided (8)
(b) Describe the procedures for cleaning EACH of the following and explain the precautions which should be taken: (8)
(i) Suction air
(ii) Turbine blades and nozzle ring
Q9. During normal engine operation, a turbocharger rapidly loses speed and the speed reduction is accompanied by appreciable noise -
A. State with reasons the possible causes.
B. Explain in detail how the engine might be safely operated if the damage caused by this incident is such that the turbocharger cannot function.
C. State with reasons the factors which may limit engine operating speed with the turbocharger out of operation.
Q5. (a) Why exhaust outlet of marine diesel engine turbocharger is lower than inlet temperature? (6)
(b) Why do we need an air cooler and why is the scavenge air temperature maintained at 40°C? (10)
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