Heat transfer principles

Question 1

The driving force that causes heat transfer is ___.

Answer 1

Temperature differential

Question 2

A tank contains 100 pounds of oil. The specific enthalpy (h) of the oil is 100 BTU/lb. the oil contains ___ total enthalpy (H).

Answer 2

10,000 BTU

Question 3

___ is the type of heat transfer that involves molecular action.

Answer 3

Conduction

Question 4

___heat transfer involves fluid or gas flow.

Answer 4

Convention

Question 5

___ heat transfer does not require flow or a medium.

Answer 5

Radiation

Question 6

Describe Energy

Answer 6

Energy can’t be created nor destroyed, but only converted from one form to another.

Question 7

The units of enthalpy are:

Answer 7

BTU/lb

Question 8

The ___ is the amount of heat that will transfer through each square foot of heat transfer surface area for each degree Fahrenheit (°F) of temperature differential.

Answer 8

Heat transfer coefficient (U)

Question 9

What is the theoretical temperature at which all molecular movements stops?

Answer 9

Absolute zero

Question 10

What describes energy?

Answer 10

Cannot be created not destroyed, only converted from one form to another.

Question 11

The units of specific heat are:

Answer 11

BTU/lb/°F

Question 12

Heat transfer is:

Answer 12

Movement is heat energy from one material or liquid to another.

Question 13

Cooling water flowing in a heat exchanger has a temperature in of 70°F; temperature out of 80°F; flow rate of 100lb/min; and a specific heat of 1 btu/lb/°F. Calculate the heat transfer.

Answer 13

1000 BTU/min

Question 14

The units for enthalpy are:

Answer 14

BTU/lb

Question 15

The type of heat transfer that involves molecular action is:

Answer 15

Conduction

Question 16

What substance has the highest specific heat capacity?

Answer 16

Hydrogen 3.45btu/lb°f

Water 1btu//lb/°f
Stainless steel .12btu/lb/°f
Iron .11btu/lb/°f

Question 17

___ heat transfer involves fluid flow.

Answer 17

Convection

Question 18

The general heat transfer equation is commonly used for all these purposes except:

• establishing maintenance schedule
• heat exchanger troubleshooting
• heat transfer problem investigation
  X heat exchange design consideration

Answer 18

Unknown

Question 19

If the tubes get dirty in a lube oil cooler but the heat load, heat transfer surface area, the cooling water flow and temperature remains constant, the lube oil temperature will:

Answer 19

Increase?

Question 20

What is another name for natural convection?

Answer 20

Natural draft

Question 21

___ Heat transfer does NOT require flow or a medium.

Answer 21

Radiation

Question 22

If the temperature difference between the hot and cold substance triples, the rate of heat transfer between them:

Answer 22

Triples

Question 23

___ is the amount of heat energy a substance contains.

Answer 23

Enthalpy