Theory of heat

Question 1

Standard atmospheric conditions

Answer 1

29.92” Hg on barometer(14.696 psia)

Question 2

Lowest temperature in °F

Answer 2

-460°F(absolute 0)

Question 3

Fahrenheit to Celsius

Answer 3

°F= (1.8x °C) + 32°

Question 4

°C to °F

Answer 4

°C= (°F-32°) \ 1.8

Question 5

Absolute temperature scales

Answer 5

°F= Rankine= -460°F
°C= Kelvin= -273°F

Question 6

British Thermal Unit (BTU)

Answer 6

Heat content of a substance

Question 7

Specific Heat

Answer 7

The amount of heat necessary to to raise the temperature of a substance 1°F per pound.

Question 8

Specific Heat of water

Answer 8

1BTU/Lb

Question 9

Specific heat of ice and steam

Answer 9

.5 BTU/Lb

Question 10

Conduction

Answer 10

Energy actually moving from one molecule to another. (A stick in a fire)

Question 11

Convection

Answer 11

Moves heat from one location to another by means of a fluid medium.
Ex. Furnace use blower to pass air over a heat exchanger and then to rooms.

Question 12

Sensible Heat

Answer 12

When a change of temperature can be registered, heat intensity has changed.

Question 13

Latent Heat

Answer 13

When heat is added but no temperature rise occurs. (Hidden heat)

Question 14

Latent heat of vaporization

Answer 14

The amount of heat energy in BTU/lb required to change a substance into vapor.

Question 15

Latent heat of vaporization of water

Answer 15

970btu/lb

Question 16

Latent heat of condensation

Answer 16

The amount of heat energy in btu/lb required to be removed to change a vapor into a liquid.

Question 17

Latent heat of condensation of water

Answer 17

970btu/lb

Question 18

Latent heat of fusion

Answer 18

The amount of heat energy required to change a solid into liquid or liquid into solid.

Question 19

Latent fusion of water

Answer 19

144btu/lb

Question 20

Saturated liquid

Answer 20

When a liquid has reached its saturated temperature, where it contains as much heat as it can without boiling.

Question 21

Superheat

Answer 21

Difference between actual temperature of a vapor and it’s saturation point.

Question 22

Pressure

Answer 22

Force per unit of area

Question 23

PSI

Answer 23

Pounds per square inch

Question 24

Lb/ft3 of water

Answer 24

62.4 lb/ft3

Question 25

Atmospheric weight

Answer 25

14.696 psi

Question 26

Barometer

Answer 26

Measures atmospheric pressure. 36” tube filled with mercury placed upside down in a puddle of mercury.

Question 27

Atmospheric pressure on barometer

Answer 27

On a barometer the tube filled with mercury will fall to to 29.92” Hg.

Question 28

Atmospheric “Hg to psi

Answer 28

29.92”Hg=14.696 psi

Question 29

Atmospheric “hg fall with altitude change

Answer 29

1” per 1000ft change in altitude.

Question 30

1psi to “Hg

Answer 30

1psi= 2.036”Hg

Question 31

Absolute pressure conversion

Answer 31

PSIg + 14.696 Ex 50psig- 50psig + 14.696= 64.696psia