102a Flashcards
Psia at absolute pressure is
14.7
Psig at absolute pressure is
0
What is British thermal unit
The heat required to raise the temperature of one pound of water by one degree fernheit
Boyles law is
A decrease in the volume and an increase in pressure, temperature is always constant
Adiabatic compression is
The compression of refrigerant gas without removing or adding heat
Adiabatic process
A change in pressure, volume, and temperature of a vapor without changing the vapors heat content
Back pressure is
Low or suction pressure
Charles law 1
A change in temperature and volume but constant pressure
Charles law 2 is
A change in absolute pressure and absolute temperature with constant volume
IDLH
Immediately dangerous to life and health
Dalton’s law of partial pressures
The total pressure of mixture gases is the sum of the individual pressure is each gas
Density is
Mass/volume
What is enthalpy
The heat in 1 pound of a substance from zero base point 0°C -40°F
Entropy is
Measurement of energy transfer where the energy is moved but not used for work
Pascals law
All pressures are equal in all directions
Canadas measurement system is
Metric
The us and British measurement system is
Imperial
A manometer reads
Liquid movement due to applied gas pressure
A ton of refrigerant is (BTU/hr)
12,000 BTU/HR
Threshold limit value (TLV) is
The refrigerant concentration in the air the people breath when they work there hours
Turbulent flow is
The chaotic flow of a fluid within the pipe
Heat is defined as
Energy in the form of molecular molecules
Specific heat is
The amount of heat required to change 1kg of a substance by 1 kelvin degree or 1lb of substance by 1 Fahrenheit
The sensible heat being removed from the gas or liquid at saturation is called
Desuperheating
Radiation travels in
Light waves
Three methods of heat transfer
Conduction
Convection
Radiation
Convection is
Heat transfer in liquids or gases, fast molecules vibrate in a space
Conduction is
Molecules increase in vibration from an energy source to the next
Thermodynamics is the study of
Changing heat energy into mechanical energy and vise versa
The first law of thermodynamics is
Energy cannot be created or destroyed
The second law of thermodynamics is
Heat moves from a high heat zone to a low heat zone
Can heat go from a low zone to high
Only if moveable is convertible to mechanical
Water to steam is how many btu
970
Water to solid btu count is
144btu
Specific heat for water, ice and steam
1.00
0.5
0.46
Q total is equal to
All sensible and latent heat
Is temperature heat
No
Temperature is the average amount of
Molecular motion in a substance
Low and high refrigerants temperature is
-20 and 39
