Exam Questions and Answers
what are the main natural types of cooling - Answer--Cooling with ice
-Evaporitive cooling
-Free cooling
-Freezing mixtures
The first principle of refrigeration is based on - Answer-laws of thermodynamics
The second law of thermodynamics states that heat cannot pass from a _______ body
to a _______ body without ? - Answer--cold
-hot
-external source of energy
what are the characteristics of a conventional refrigeration cycle - Answer--Transfer of
heat from a colder substance to hotter
-refrigerant is used to remove heat and transfer it elsewhere
-movement of heat requires energy input
-cooling
Conventional refrigeration operates on a thermodynamic cycle called - Answer-reverse
heat engine
The two main principles used for conventional refrigeration are - Answer--gas expansion
-evaporation of volatile liquid
Cyrogenic refrigeration may take several forms but the two common methods that the
power engineer may encounter are - Answer--Turboexpansion
-Joule Thomson expansion
Vapour compression refrigeration: This method involves a cycle where refrigerant is
compressed and condensed before passing through an expansion device located -
Answer-Upstream of an evaporator
Absorption refrigeration: This method uses ______ as refrigerant an absorbent such as
_______ and a _______ input - Answer--water
-ammonia
-heat
vacuum and steam jet system: - Answer-water exposed to a vacuum will evaporate and
absorb heat
, Reverse Brayton cycle: This method refers to the cyclical compression and expansion
of __________. When a gas such as air expands from high to low pressure its
temperature is reduced which allows what ? - Answer--Non condensable gases
-absorbing of heat from its surroundings
Throttling process (Joule-Thomson expansion) - Answer-real gas is throttled without any
energy change
A turbo expander or is a turbine that is used to - Answer--drop the pressure of the gas in
order to cool the gas or recover the energy
what does isothermal mean - Answer-constant temperature
pg.445
commercial refrigeration applications include systems and appliances used for the -
Answer-storage an display of food and beverage
A refrigerant truck trailer is a method for shipping freight that - Answer-requires special
temperature controlled vehicles
_______________ includes applications such as cold storage meat and fish processing,
dairy processing and beverage production - Answer-Industrial refrigeration
what are some methods of freezing - Answer--blast freezing
-Contact freezing
-spiral freezing
-Cryogenic freezing
Generally the ice ina rink is maintained at a thickness of ______ by bypassing a
chilledbrine refrigerant through a grid of pipes in the ice rink - Answer-25mm
Mechanical refrigeration is used in natural gas processing for _________ of both
hydrocarbons and water - Answer-dew point control
A mechanical refrigeration plant that uses propane or another refrigerant is used to chill
the glycol mixture to about - Answer--20c
Turbine inlet air cooling (TIAC) is used in - Answer-hot climates with high ambient
temperature
The Claude process uses an _______ for _________ of the gas stream and a throttling
valve (J-T) for remaining _________ - Answer--expansion turbine
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