Solar energy can be directly used in
Air refrigeration system
Jet refrigeration system
Vapour compression refrigeration system
Vapour absorption refrigeration system
In an Electrolux refrigerator, there is
Absorption of ammonia in water
Absorption of hydrogen in water
Evaporation of ammonia in hydrogen
Evaporation of water in an atmosphere of some inert gas
The refrigerant commonly used for commercial ice plants is
Freon-12
NH3
CO2
Air
Electrolux refrigerator essentially works on vapour
Absorption system
Vapour compression system
Thermo-electric system
Vortex tube system
Hydrogen is essential in an Electrolux refrigeration system, because
It acts as a catalyst in the evaporator
It helps in maintaining a low partial pressure for the evaporating ammonia
The cooled hydrogen leaving the heat exchanges tools the refrigerant entering the evaporator
The reaction between hydrogen and ammonia is endothermic in evaporators and exothermic in adsorbate
Choose the wrong statement:
Sub cooling in a vapour compression system occurs when sensible heat is removed from the refrigerant during condensation process
Vapour absorption systems find favour in big refrigeration plants having capacity of the order of 1000 tons
The work input requirement in ammonia refrigeration system is high because pumping process involves vapour
Reagents are used to detect leakage in a brine system
Suggest the type of refrigeration system used to obtain chilled water with the application of the principle of flash cooling:
Vortex system
Steam jet refrigeration system
Vapour absorption system
Electro-chemical system
Consider the following statements:
The installation of flash chamber in a refrigeration system
reduces the pressure losses through the evaporator
reduces the size of evaporator by not allowing the vapours to go to the evaporator
improves over all heat transfer
Which of those statements are correct?
1 and 2
2 and 3
1 and 3
1, 2 and 3
Which of the followings is not a desirable property of a good refrigerant?
Low specific heat
High specific volume of vapour
Large latent heat at evaporator pressure
High critical temperature
Low boiling point
Which is not true in respect of an ideal refrigerant?
High latent heat of vaporization and specific heat
Critical pressure and temperature well above the maximum operating pressure and temperature limits
Low value of specific volume
High value of thermal conductivity
The critical temperature is the temperature
Above which explosion of gas occurs
Above which a gas will never be liquefied
Below which a gas is always liquefied
Below which a gas does not obey gas laws
The relative humidity does not represent the ratio of
Mass of water vapour in a given volume of mixture to the mas of water vapour in an equal volume of saturated mixture at the same temperature
Partial pressure of water vapour in the mixture to the saturation pressure of water vapour at the mixture temperature
Specific volume of saturated steam at the mixture temperature to the specific volume of steam in the mixture
Specific humidity of a given volume of mixture to the specific humidity of the saturated mixture under identical pressure and temperature conditions
The temperature of air-water mixture recorded by a thermometer when its bulb is covered with a wick saturated with water and placed in the air-water stream is called
Wet bulb temperature
Dew point temperature
Saturation temperature
Critical temperature
When the temperature of air is reduced by continuous cooling at constant pressure, the condensation of water starts at a particular temperature known as
Wet bulb temperature
Dew point temperature
Adiabatic saturation temperature
Critical temperature
The temperature attained when the air is cooled by adding water adiabatically to it in a steady flow until it becomes saturated is called
Wet bulb temperature
Dew point temperature
Adiabatic saturation temperature
Wet bulb depression
Wet bulb depression represents the difference between
Dry bulb temperature and wet bulb temperature
Dry bulb temperature and dew point temperature
Dew point temperature and saturation temperature
Adiabatic saturation temperature and dew point temperature