問題一覧
1
A liquid vaporizing without addition of the heat caused by a pressure drop
flashing
2
if you reduce the volume of a contain vapor will you reduce or rise lower pressure
Rise, vapor pressure
3
Amount heat it takes 1 pound of water 1 degree Fahrenheit
1 BTU
4
What is the state of refrigerant coming out the evaporator
Superheat vapor
5
which device is metering device
thermostatic expansion valve
6
what’s the name of the line that carry superheat vapor from now evaporator to the compressor
suction line
7
which component absorbs heat
Evaporator
8
what is the purpose of a psychrometer
Measure, wet bulb
9
when is a recovering cylinder full
80% water capacity
10
which system measurement is most effective by relative humidity
Delta T
11
relative humidity
Air temperature
12
what are the 3 method of heat transfer
Convention, conduction, radiation
13
how much heat absorbed with 3 tons of cooling
36,000 BTU per hour
14
define recovery
to remove refrigerant and moving it to a external container
15
sub cooling is measures where
Liquid line
16
what type of oil is used in HFC refrigerant
Polyester
17
the minimum vacuum we pull
500 microns
18
what temperatures must be measured to find delta T
Return and supply
19
which component rejects heat
condenser
20
what’s the material in a filter dryer?
Desiccant
21
why do we pull a vacuum
To remove moisture and noncondensibles
22
what used to connect copper tubing to other devices without blazing it
Flaring
23
what is a purpose of a compressor
pump refrigerant vapor rise temperature rise pressure all of above
24
define refrigeration
to remove heat where its not wanted and moving it where it does not matter
25
What is the pressure scale 14.7
PSIA
26
what is the specific heat of ice
0.5 BTU
27
when charging a stystem with the compresser running the refrigerant is added
Added to the low side
28
2 methods of recovery
self-contained and system dependent
29
what side is compound gauge connected
Low side
30
what is the purpose of metering device
Regulate refrigerant flow
31
which of the following is type of evaporter
A-coil
32
how many Cfm per ton minimum
400 CFM
33
which gas should be use to pressure test
nitrogen
34
Second law of thermodynamics
Hot goes to cold
35
At what point is refrigerant changing state
saturated
36
metering device is located
at the inlet of evaporator
37
what must be connected to the end of the manifold hoses
Low loss fittings
38
what type of refrigerant will fractionate during change of state
Zeotrope
39
cooling a liquid below saturation temperature
Subcooling
40
what type of gauge measures above and below
compound gauge
41
what component of R-22 is responsible ozane depletion
chlorine
42
purpose of fiter dryer
Removes debris and dehydrate