In this post you will get an insight of what type of
questions that are asked in the marine refrigeration, cargo ventilation, noise,
and vibrations. It will prove beneficial for the exams and if you are sitting
for an interview in the shipping company.
questions that are asked in the marine refrigeration, cargo ventilation, noise,
and vibrations. It will prove beneficial for the exams and if you are sitting
for an interview in the shipping company.
Q1: Make a
sketch of simple refrigeration circuit and describe the operation of circuit.
sketch of simple refrigeration circuit and describe the operation of circuit.
Q2: Make a line
diagram of a Freon – 22 refrigeration circuit showing the relative position of
the main components in the system and the direction of flow in all lines.
diagram of a Freon – 22 refrigeration circuit showing the relative position of
the main components in the system and the direction of flow in all lines.
Q3: Sketch and
label a thermostatic expansion valve as fitted to a vapor compression
refrigeration system and explain its operation.
label a thermostatic expansion valve as fitted to a vapor compression
refrigeration system and explain its operation.
Q4: State the
desirable properties of refrigerant and how these influence the design of
system.
desirable properties of refrigerant and how these influence the design of
system.
Q5: State the
function of following devices fitted on the refrigeration system:
function of following devices fitted on the refrigeration system:
High pressure cut out switch
Magnetic liquid stop valve
Oil pressure switch
Low pressure cut out switch
Oil separator
Dryer
Q6: Explain
what is meant by short cycling, describe a halide torch and how is it used for
leak detection in refrigeration system?
what is meant by short cycling, describe a halide torch and how is it used for
leak detection in refrigeration system?
Q7: State under
cooling and super heating, where these take place in a refrigeration plant.
Describe their effect on the efficiency of plant and show them on pressure
enthalpy curve.
cooling and super heating, where these take place in a refrigeration plant.
Describe their effect on the efficiency of plant and show them on pressure
enthalpy curve.
Q8: Sketch a
typical domestic refrigeration plant with control for automatic operation and
describe it. State specific temperature maintained in different rooms.
typical domestic refrigeration plant with control for automatic operation and
describe it. State specific temperature maintained in different rooms.
Q9: What is air
conditioning? Sketch and describe a single duct system.
conditioning? Sketch and describe a single duct system.
Q10: What is
relative humidity? How is it calculated? State the typical comfort condition.
How can it be achieved in summer & winter?
relative humidity? How is it calculated? State the typical comfort condition.
How can it be achieved in summer & winter?
Q11: Give causes
for the following troubles in air conditioning plant:
for the following troubles in air conditioning plant:
Compressor short cycles
Discharge pressure too high
Suction pressure too high
Compressor fails to start
System short of capacity
Questions related to cargo ventilation and axial flow compressors
Q1: Discuss the
necessity of shipboard ventilation? Explain low and high velocity system and
their relative merits?
necessity of shipboard ventilation? Explain low and high velocity system and
their relative merits?
Q2: Describe a
suitable ventilation plant for ship’s engine room and explain the air
distribution arrangement.
suitable ventilation plant for ship’s engine room and explain the air
distribution arrangement.
Q3: Write a
note on modern techniques of ship’s engine room ventilation.
note on modern techniques of ship’s engine room ventilation.
Q4: Explain the
purpose of ship’s cargo hold ventilation. What methods are used for it?
purpose of ship’s cargo hold ventilation. What methods are used for it?
Q5: Describe
with sketches the arrangement of ventilating
with sketches the arrangement of ventilating
Living spaces
Passageways
Sanitary spaces
Dining saloon
Pantry
Galley
Hospital
Working space of ship
Q6: Explain the
general principles of operation of fan. State the fundamental fan laws &
distinguish between various types of fans.
general principles of operation of fan. State the fundamental fan laws &
distinguish between various types of fans.
Q7: Sketch and
describe the construction of a centrifugal blower used on air handling units of
ships AC plant?
describe the construction of a centrifugal blower used on air handling units of
ships AC plant?
Q8: Sketch
& describe a centrifugal fan used in turbocharger of a marine diesel
engine.
& describe a centrifugal fan used in turbocharger of a marine diesel
engine.
Q9: Sketch and
describe an axial flow compressor used as exhaust blower in pump room of an oil
tanker.
describe an axial flow compressor used as exhaust blower in pump room of an oil
tanker.
Q10: Write short
notes on:
notes on:
Mach number
Pre whirl vanes
Characteristic curve of centrifugal blower
Backward swept, radial tipped & forward swept blades/
vanes
vanes
Question related to Noise and vibrations
Q1: What are
the sources of noise on ship and describe the methods to suppress it?
the sources of noise on ship and describe the methods to suppress it?
Q2: What is the
unit of sound and how can it be measured?
unit of sound and how can it be measured?
Q3: What are
the detrimental effects of noise on human body? How one can protect himself
from ill effects of noise on ship?
the detrimental effects of noise on human body? How one can protect himself
from ill effects of noise on ship?
Q4: Can noise
be used as a useful parameter? Justify your answer with suitable explanation.
be used as a useful parameter? Justify your answer with suitable explanation.
Q5: What is the
mechanism of noise production and its behavior in enclosed spaces>
mechanism of noise production and its behavior in enclosed spaces>
Q6: What is
vibration and how is it caused on ships? Describe various forms of mechanical
vibration.
vibration and how is it caused on ships? Describe various forms of mechanical
vibration.
Q7: What is
resonance? How are hull vibration caused?
resonance? How are hull vibration caused?
Q8: What is
meant by critical speed and barred speed range? What is it’s effect on torsinal
vibration?
meant by critical speed and barred speed range? What is it’s effect on torsinal
vibration?
Q9: What are
dampers and detunes and how they reduce vibrations?
dampers and detunes and how they reduce vibrations?
Q10: What is a
torsiograph, how it works and what is its use on ship?
torsiograph, how it works and what is its use on ship?
Can you give me information regarding written exam involved in selection procedure of shipping company, whether the written exam is MCQ based, or objective type or long answers type.
Thank you,