Explain the state of the refrigerant as it enters the compressor and as it exits the compressor
The refrigerant enters the compressor as a low pressure warm gas and exits as a High pressure hot gas.
11 of 24
Explain the state of the refrigerant as it enters the condenser and as it exits the condenser.
The refrigerant enters the condenser as a high pressure hot gas and exits the condenser as a high pressure warm liquid, this is achieved by using a seawater cooling medium.
12 of 24
Explain the state of the refrigerant as it enters the TEV and as it exits the TEV.
The refrigerant enters the TEV as a high pressure warm liquid, and exits as a low pressure very cold liquid.
13 of 24
Explain the state of the refrigerant as it enters the evaporator and as it exits the evaporator.
The refrigerant enters the evaporator as a low pressure very cold liquid and exits as a low pressure warm gas.
14 of 24
What are the two colours on a sight glass indicator and what do they represent ?
Green- Indicates dry(No moisture in the system).
Yellow-Indicates Moisture in system.
15 of 24
List the three methods of defrosting and how long they can be carried out for.
Natural defrosting-(No time limit, done at regular intervals for maintenance (3-6 Months))
Hot gas defrosting-(Max of 1 hour a day(4x15 mins) to prevent cooking oil)
Electrical heating coils-(Max of 1 hour a day again to prevent cooking oil in evaporator)
What Refrigerant is used in the RN and what is its boiling point ?
R134A has a boiling point of -26.5C
20 of 24
List the three ways oil can be added to a sump.
Sump filler plug
Hand pump
Dosing pot
21 of 24
What does the chilled water plant cool ?
Weapons systems
Radars
Ship computer system
Air treatment units(ATU's)
22 of 24
What temperature does cooled water leave the chiller at and what temperature does it re enter the chiller at ?
Cooled water leaves the chiller at 4C to 6C
and returns at 13C to 20C
23 of 24
List 5 hazards associated with refrigeration and chilled water plants.
1.Refrigerant in the atmosphere(can not support life)
2.Contact of refrigerant with skin(Frost bitten)
3.Gases produced in refrigeration are heated(can turn into mustard gas)
4.Refrigeration machinery space dangers
5.correct machinery room entry procedure
24 of 24
Other cards in this set
Card 2
Front
As altitude decreases below sea level what happens to the pressure, volume and energy required to boil a substance ?
Back
As altitude decreases below sea level, pressure increases, volume decreases and the energy required to boil a substance is greater.
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