DieselShip's Online Content Library

Q1. (a) Explain the construction, working principle, and control philosophy of the modern electronically controlled two-stroke marine diesel engine. (8)

(b) Discuss the contrast in its fuel injection and exhaust valve actuation mechanisms, with conventional (mechanically controlled) engines, and detail the advantages it offers regarding emissions and fuel efficiency. (8)

Q2. a) Describe, with the aid of a sketch, a main engine holding down system explaining how the design features help prevent excessive stress in the holding down studs (8)

b) Describe, with the aid of a sketch, an engine top bracing arrangement, explaining why they are fitted and checked for operational performance (8)

Q3. With reference to abnormal and excessive cylinder liner wear:

(a) Explain how it may be caused, stating how it is detected: (4)

(b) Explain the effects and consequences of excessive cylinder liner wear (4)

(c)  Explain how abnormal cylinder liner wear may be prevented. (4)

(d) Explain how the liner wear rate is calculated. (4)

--- PREVIOUSLY ASKED AS ---

2021/AUG/02 - 2021/SEP/06

Q6. With reference to large two stroke engine:

(a) Explain how abnormal and excessive cylinder liner wear caused, state how it can be detected:

(b) Explain the effects and consequences of excessive cylinder liner wear

(c)  Explain how abnormal cylinder liner wear may be prevented.

Q4. a) Sketch a commonly employed method of attachment between crosshead and slippers. (8)

b) Explain why guide clearance is strictly limited. (4)

c) Give reasons why lubricant is usually fed to the slippers and not the guides. (4)

Q5. With regards to modern diesel engine raising the Life Cycle Value (LCV) describe the importance of following. (16)

(a) Low Sac Volume of Fuel Injection Valve.

(b) Fuel Valve opening Pressure regulation.

(c) Contamination of combustion Chamber and impact on LCV.

(d) Contamination of lube oil and impact on LCV.

Q6. With reference to a Closed Loop engine exhaust gas SOX scrubber system:

a. Describe, with the aid of a sketch, such a system. (8)

b. State, with reasons, the fluid which is used for SOX scrubbing in this system. (3)

c. State how the effectiveness of the scrubbing fluid is maintained and how the sludge is removed and disposed of. (5)

Q7. With reference to a waste heat boiler/economiser:

a. Write a procedure for the cleaning of the gas side of a waste heat 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)
- - - PREVIOUSLY ASKED - - -

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;  (ii) stopped.

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

Q8. a) Explain why pilot injection is required for a Dual fuel engine when burning natural gas. (4)

b) Describe, with the aid of a sketch, the arrangements for a dual fuel engine which is capable of burning natural gas on:

          a) The otto cycle.

          b) The Diesel cycle (12)

Q9. Analyse the problem of cylinder liner lubrication with reference to oil injection timing relative to piston position, speed and direction of motion. Describe the worst effects of inaccurate lubricant injection timing and how it can have a detrimental effect on developed power in the cylinder. Describe with sketches the arrangement for conveying the oil through the cylinder jacket. (16)