refrigeration and hazards

Question 1

TEV?

Answer 1

thermal expansion valve

Question 2

3 ways to make heat

Answer 2

convection: radiators etc
conduction: heat travelling from hot to cold
radiation: heat from the sun (sunburn)

Question 3

two types of heat and what they are

Answer 3

sensible: state stays the same, but temperature is added
latent: state changes but temperature remains the same

Question 4

where does subcooling stand in terms of temperature

Answer 4

90 degrees celsius

Question 5

LP cut out

Answer 5

cuts off the compressor if pressure isn’t enough

Question 6

HP cut out

Answer 6

cuts off compressor is there’s too much pressure

Question 7

oil separator purpose

Answer 7

separates oil from the gas, and the oil is returned to the compressor

Question 8

liquid receiver purpose

Answer 8

acts as a reservoir for liquid produced

Question 9

drier and sight glass purpose

Answer 9

removes moisture from the refrigerant, on the glass dial it will indicate whether it’s good or bad by green or yellow

Question 10

three ways to defrost

Answer 10

naturally, hot gas defost, and electrical heat coils

Question 11

natural defrost

Answer 11

turn it off and let it defrost itself

Question 12

hot gas defrost

Answer 12

performed for an hour (4 x 15mins) everyday

Question 13

coils

Answer 13

coils are wrapped around the evaporator an hour before

Question 14

montreal and kyoto protocols

Answer 14

phasing out CFC’s around the world
about greenhouse gases and the reduction of using them

Question 15

ways to spot a leak

Answer 15

IRDLS infra-red leak detection system
oil slicks
spectrolyne dye and UV lamp
snoop (soapy water)
halogen leak detector

Question 16

types of oil

Answer 16

OM70: general purpose refrigerant oil used with CFC machines
SUNISO: synthetic oil used on 23’s and T boats
SW68: synthetic used on R134a refrigerants

Question 17

how oil can be added to refrigerant systems

Answer 17

sump filler plug
hand pump
dosing pot

Question 18

what chilled water plants provide chilled water for?

Answer 18

weapons systems
radars
ships computer system
air treatment units ATU’s

Question 19

chilled water temperature?

Answer 19

4-6 degrees celsius

Question 20

refrigerant leak gas?

Answer 20

phosgene/mustard gas

Question 21

precautions for going into the freezer?

Answer 21

check the safety lights, and handles
take a refrigerant gas monitor in with you beforehand
make sure exhaust fans are running

Question 22

what’s the ventilation used for?

Answer 22

cooling of electric equioment
CBRN
habitability
main machinery space cooling
galley venitlation

Question 23

what’s the ventilation used for?

Answer 23

cooling of electric equipment
CBRN
habitability
main machinery space cooling
galley ventilation

Question 24

four basic combinations for supply and exhaust vents

Answer 24

fan supply and exhaust
fan supply and natural exhaust
natural supply and fan exhaust
natural supply and exhaust

Question 25

types of filters and uses

Answer 25

panel filters: for vents susceptible to bad stuff
supply filters: ATU’s
grease filters: galleys
lint filters: laundry
dust filters: computers and sickbay
flameproof gauze: inflammable stores, hangers etc

Question 26

vent systems identification numbers

Answer 26

first number: denotes which deck
second: denotes which section
third: position of the fans, odd for starboard and even for port

Question 27

places which require special filters

Answer 27

galleys
store rooms
magazines
paint stores
auxiliary machinery spaces

Question 28

special requirement vent places, and why

Answer 28

galley: due to increased risk of fire
aux machine space: subject to build up of fumes so 50% of vents are above deck
STP’s: requires 15 air changes an hour due to conditions
magazines: rooms with weapons aren’t vented normally, they’re fitted with 100% naturally treated air

Question 29

citadel tests and when carried out

Answer 29

annually
prior to extended docking periods
during harbour acceptance trials
during sea acceptance trials
required during FOST

Question 30

how a citadel test is conducted

Answer 30

close all openings on the citadel boundary and system on resirc’
open AFU’s
restrict access to and from the citadel
search for leaks and do temporary repairs
record the results on paper

Question 31

crash stop ventilation

Answer 31

allows all vents to be stopped immediately during fires etc