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 action.
Q4. Referring to latest developments in Turbo charger application in marine diesel engines, write short notes on the following:-
(a) Power turbines Generators.
(b) Hybrid Turbo Chargers.
(c) Electro-assist Turbo chargers.
Q8. a) To improve the power-to-weight ratio of an engine, it is necessary to increase the mep. Discuss the importance of turbocharger compression ratio in this regard. Why has it become necessary to introduce two-stage turbocharging?
b) With reference to turbochargers with variable turbine area, explain
i)Which area is varied
ii)Why is it varied
iii)How is it varied.
Q4. Many modern turbochargers use sleeve type bearings for rotor support.
A. Explain the reasons for their preference over the rolling contact bearings;
B. With a sketch describe the lubricating system provided for this type;
C. In a turbocharger with integral type of bearings, describe the procedure for renewing the bearings.
Q8. 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.
Q5. With reference to main turbochargers:
a) Give a reason why binding wire is frequently fitted near the top of the blades
b) Mention one fault that occasionally develops with binding wire in services,
c) Define the cause and identification under running conditions of turbine blade damage
d) State how (c) can be largely avoided.
Q6. with reference to a slow speed diesel engine fitted with a single turbocharger. describe, with reasons, the possible action which could be taken to enable the main engine to be operated, If whilst on oceanic passage, a small portion of one of the impeller vanes breaks off and impacted with the charge air cooler.
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.
Q2. Explain why the following problems occur in turbocharger nozzles, shrouds and blades, their effects on turbocharger operation and remedies: – A. Build-up of deposits; B. Hot corrosion; C. Erosion
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.