[Refrigeration Systems]

Question 1

Instantaneous evaporation of liquid refrigerant in an evaporator

Answer 1

Flash gas

Question 2

What may be closed to prevent toxic or dangerous vapors from entering the vessel?

Answer 2

Dampers

Question 3

Carries the refrigerant vapor from the evaporator to the compressor

Answer 3

Suction line

Question 4

Four variables that the design of a capillary tube depends on

Answer 4

• Tube length
• Inside diameter
• Tightness of tube windings
• Temperature of tubing

Question 5

Two types of piston rings

Answer 5

• Compression ring - upper ring

* Oil ring - lower ring designed to control the oil “flow” past the piston

Question 6

What type of thermometer detects infrared rays produced by a substance?

Answer 6

Radiometer

Question 7

Three types of compressors

Answer 7

• Hermetic
• Semi-hermetic
• Open type (externally driven)

Question 8

Amount of heat required to raise the temperature of one pound of water one degree Fahrenheit

Answer 8

BTU

Question 9

Process in which a gas is compressed without losing heat to the surroundings

Answer 9

Adiabatic compression

Question 10

Safety device that prevents liquid refrigerant from flowing into the suction line and compressor

Answer 10

Accumulator

Question 11

Serves as a pressure plate in a cylinder, supporting and holding the valves and valve plate in position

Answer 11

Cylinder head

Question 12

Connects to the lower end of the piston by means of a floating bearing in a Scotch yoke mechanism

Answer 12

Crankthrow (crankshaft pin)

Question 13

1) Maintains proper flow of refrigerant; provides and controls refrigerant
2) What are the two types?

Answer 13

1) Refrigerant metering device

2) Thermostatic-controlled expansion valves and capillary tubes

Question 14

Vapor formation in a capillary tube

Answer 14

Vapor lock

Question 15

Leak-proof container that houses crankshaft

Answer 15

Crankcase

Question 16

Back-and-forth action in a straight line

Answer 16

Reciprocating

Question 17

Heat is a form of what?

Answer 17

Energy

Question 18

SI metric unit of heat

Answer 18

Joule (J)

Question 19

Connecting rods that are shorter than the master connecting rod

Answer 19

Articulated rods

Question 20

Four components of refrigeration

Answer 20

• Compressor
• Condenser
• Refrigerant control device
• Evaporator

Question 21

What is the most damaging condition of refrigeration operation?

Answer 21

Refrigerant slugging (allowing liquid refrigerant to enter the compressor)

Question 22

What discharge air from the vessel to the atmosphere?

Answer 22

Exhaust system and fans (axial and centrifugal)

Question 23

What measures the heat intensity or heat level of a substance?

(measures the speed of motion of the atom)

Answer 23

Temperature

Question 24

What is happening when a fluid evaporates?

Answer 24

Heat is absorbed

Question 25

Coils cooled by brine or any fluid which does not evaporate in the coil

Answer 25

Cooling coils

Question 26

Contact device with a remote bulb mounted in the duct or plenum of an air handling unit to measure air temperature in such a way that it does not see radiant heat directly from the heater

Answer 26

Duct thermostats

Question 27

How is temperature measured?

Answer 27

Thermometer

Question 28

Part of refrigerator mechanism where liquid refrigerant boils or evaporates and absorbs heat

Answer 28

Evaporator

Question 29

Volume of space between piston and cylinder head at TDC

Answer 29

Clearance space

Question 30

Motor-driven device which removes the heat-laden vapor refrigerant from the evaporator

Answer 30

Compressor

Question 31

Expendable refrigerant usually used in an expendable refrigerant refrigeration system

Answer 31

Liquid nitrogen

Question 32

What is the moisture level?

Answer 32

Humidity

Question 33

What consists of duct heaters, unit heaters, and convection heaters?

Answer 33

Heating system

Question 34

What maintains correct operating temperature by controlling the motor electrical circuit?

Answer 34

Thermostat

Question 35

What are the major supply systems feeding air into the vessel?

Answer 35

Air intake trunks (ducts)

Question 36

What are the major components in an air conditioning cooling cycle?

Answer 36

* Cooling coil * Compressor * Condenser * Expansion valve (or capillary tube assembly)

Question 37

Temperature of the air surrounding a motor, control mechanism, or any other device

Answer 37

Ambient temperature

Question 38

What provides local filtering and reheating or cooling of air?

Answer 38

Recirculating (return air) system

Question 39

Mechanical refrigeration cycle

Answer 39

* Closed system * Continuously circulating * Condensation * Evaporation

Question 40

Temperature control device that is mounted on the wall in the area which it serves

Answer 40

Room thermostats

Question 41

What is the SI unit of temperature?

Answer 41

Kelvin (K)

Question 42

When does the HVAC process begin?

Answer 42

As weather air enters the HVAC supply intakes

Question 43

Pressure of a vapor in contact with a liquid

Answer 43

Vapor pressure

Question 44

Instrument used when accurate readings at various temperatures are needed

Answer 44

Thermometer-pyrometer | Pyrometer means “high temperature

Question 45

Three safety considerations

Answer 45

* Safety of operator * Safety of equipment * Safety of content

Question 46

What is the American conventional unit of temperature?

Answer 46

Fahrenheit

Question 47

What move the air through the supply ducts to ventilate compartments and to heat or cool the air?

Answer 47

Supply fans

Question 48

Amount of heat required to raise the temperature of one gram of water one degree Celsius

Answer 48

Calorie

Question 49

What is often done to the connections of a capillary tube?

Answer 49

Brazed

Question 50

What removes air from the galley along with all cooking smoke and odors?

Answer 50

Galley exhaust fan

Question 51

Unit which equals 100,000 BTU

Answer 51

Therm

Question 52

Sequence of events

Answer 52

* Liquid line * Expansion valve * Evaporator * Suction line * Compressor * Discharge line * Condenser

Question 53

What does the operation of a mechanical refrigerator rely on?

Answer 53

Heat absorption property of a fluid passing from the liquid to the vapor state

Question 54

Shaft section which is larger and has a different center than the shaft

Answer 54

Eccentric

Question 55

Type of refrigerant control that consists of a length of seamless tubing with a small and accurate inside diameter

Answer 55

Capillary tube

Question 56

What is the thermal energy of the atom multiplied by the number of atoms (mass)?

Answer 56

Heat

Question 57

What does a substance state consist of?

Answer 57

* Pressure * Heat content * Temperature

Question 58

What is the American conventional unit of heat?

Answer 58

British Thermal Unit (BTU)

Question 59

Temperature where molecular motion stops (all heat is removed) *lowest temperature possible

Answer 59

Absolute zero

Question 60

What happens when a gas is compressed?

Answer 60

Temperature rises (heat of compression)

Question 61

1) Insulated cabinet equipped with a tray or tank at the top for holding blocks or pieces of ice 2) What is the advantage?

Answer 61

1) Typical ice refrigerator | 2) Maintaining the interior of the cabinet at a fairly high humidity

Question 62

Keeps moisture, dirt, metal, and chips from entering the refrigerant flow control

Answer 62

Liquid line filter-drier

Question 63

How does natural air enter a room?

Answer 63

Door louvres