DieselShip's Online Content Library

Q7. Write a report to the engineering superintendent regarding the replacement at sea of a damaged main engine cylinder cover. The report must explain how the problem was detected, the likely cause of the damage and the action which has been instituted to prevent further incidents of this type. (16)

Q9. (a) Explain why highly efficient diesel engines tend to produce more NOx than low performance diesel engines. (4)

(b) Describe, with the aid of a sketch, a Selective Catalytic Reduction (SCR) unit for a marine propulsion diesel engine.

(c) Explain why accurate monitoring of the exhaust gas flows entering and leaving a Selective Catalytic Reduction unit are required and how these readings are used to control the reduction chemical supplied to the SCR unit.

Q3. (a) Explain why a diesel engine cylinder is supplied with excess air. (4)

(b) Explain why fuel droplet size produced during injection has to be within narrow limits in order to enable good cylinder combustion to be achieved. (4)

(c) Explain how the desired fuel droplet size is produced by fuel injectors. (4)

(d) State why fuel injection timing has to be within narrow limits to enable economic engine operation without bearing overload. (4)

Q5. Write a procedure for the actions to be taken in the event of an engine Oil mist alarm being activated, stating the reason for EACH action. The procedure must cover the period from activation of the alarm to return of the engine to normal operation. (16)

Q3. (a) Describe, with the aid of a sketch, either a diesel engine Open Loop Sox scrubber system or a Closed Loop Sox scrubber system.?? (10)

(b) Explain what systems need to be monitored in order to ensure that the scrubber system meets all IMO regulations.

Q2. With reference to main engine crankcase explosions:

a. Explain the cycle of events leading to a secondary crankcase explosion; (6)

b. As Chief Engineer, explain how an engine system should be managed in order to minimise the risk of a crankcase explosion and the effects of a crankcase explosion should one occur. (10)

Q7. (a) State, with reasons, THREE engine operating parameters which should initiate an automatic slowdown if engine operation is outside of set value conditions; (6)

(b) Describe how the operation of each slowdown listed in part (a) may be tested; (6)

(c) List two engine operating parameters which should initiate an automatic engine shutdown, in EACH case explaining why this parameter MUST shut down the engine (4)

Q9. With reference to a waste heat boiler/economiser:

a. Write a procedure for the cleaning the gas side of an exhaust gas boiler/economiser when the

associated main engine is:

(I) running; (5)                              (ii) stopped. (5)

b. Write a procedure for operation of the main engine when the associated waste heat boiler/economiser cannot be operated due to tube failure. (6)