Low Pressure Boilers Ch 10
Heat flows from a cold material to a hot material.
False
Common condenser designs include ___ condensers.
shell-and-coil, shell-and-tube, & tube-in-tube
A scroll compressor has reciprocating cylinders to compress the refrigerant.
False
An absorption refrigeration system uses a compressor to provide pressurized ammonia to the system.
False
Chlorofluorocarbons (CFCs) are present in all refrigerants used in compression systems.
False
Direct cooling systems are used where the space or product to be cooled is located a considerable distance from the condensing equipment.
False
Heat is released by the refrigerant at the evaporator.
False
If the pressure on a refrigerant increases, the boiling point decreases.
False
In a compression refrigeration system, heat transfer occurs at the expansion valve and the compressor.
False
Indirect cooling systems use refrigerant piped to the space or product to be cooled.
False
Latent heat is the amount of heat that changes the temperature of a substance but not the state of a substance.
False
Refrigerant pressure is controlled by the expansion valve located between the evaporator and the compressor.
False
The evaporator is located on the high pressure side of a cooling system.
False
When refrigerant gas is compressed, the temperature and pressure are lowered.
False
_____ refrigerants do not contain chlorine and are safer for the environment.
HFC
In a refrigeration system, heat is ___ when a fluid changes from a gas to a liquid.
In a refrigeration system, heat is ___ when a fluid changes from a gas to a liquid.
A refrigerant absorbs heat when changing from a liquid to a gaseous state.
True
Air conditioning systems are cooling systems used to cool air for comfort in building spaces.
True
Chiller systems are commonly used in refinery, brewery, and dairy applications.
True
Compression refrigeration systems are commonly used for air conditioning applications.
True
Cooling systems use equipment similar to hot water heating systems.
True
Heat energy can be changed to mechanical energy.
True
In a direct cooling system, the evaporator is in direct contact with the space or product being cooled.
True
In a lithium bromide and water system, heat is applied at the generator.
True
In a refrigeration system, heat is absorbed when a fluid changes from a liquid to a gas.
True
Latent heat is heat added to a substance that changes its state without a change in temperature.
True
Liquid refrigerant leaves the condenser under high pressure before reaching the expansion valve.
True
Refrigerant is changed from a liquid to a gas in the low pressure side of a compression system.
True
Refrigerant is converted from a gas to a liquid in the condenser.
True
Refrigerants used in a compression refrigeration system must have a boiling point below the temperature of the air leaving the evaporator.
True
Some cooling systems can be designed to share components with a hot water heating system.
True
Water is the most common medium used to transport heat from the area to be cooled.
True
When ice changes into water, there is a change in state.
True
Cooling units that cool building spaces are designed to ___ heat from the air.
absorb
In a lithium bromide system, cooling water is directed through the ___ and condenser to remove heat.
absorber
In a(n) ___ system, water is commonly used to absorb heat from the product or space to be cooled.
chilled water
Indirect cooling systems commonly use ___ as a medium to cool the space or product.
chilled water
Water chilled in a cooling system is chilled by the ___.
chiller
An absorption refrigeration system includes all of the following except the ___.
compressor
In a compression refrigeration system, the ___ is used to change the pressure of a refrigerant gas.
compressor
In a compression refrigeration system, high pressure vapor is converted from a gas to a liquid in the ___.
condenser
In a compression refrigeration system, the refrigerant absorbs heat in the ___.
evaporator
In a compression refrigeration system, liquid refrigerant under high pressure is allowed to drop in pressure by the ___.
expansion valve
In a lithium bromide and water refrigeration system, heat is commonly applied with steam coil at the ___.
generator
Heat added to a substance that changes its state without a change in temperature is ___ heat.
latent
The compressor will be damaged if ___ refrigerant is allowed to enter.
liquid
Absorption refrigeration systems may use ___ as a refrigerant.
lithium bromide and water
In a compression refrigeration system, heat is absorbed by the refrigerant in the ___.
low pressure side
Refrigerants used in a compression system must be ___.
noncorrosive, chemically stable, nonflammable
In indirect cooling systems, ___ used as a medium must be kept above 32°F.
water
