A thermostatic expansion valve in a refrigeration system
Ensures the evaporator completely filled with refrigerant of the load
Is suitable only for constant load systems
Maintains different temperatures in evaporator in proportion to load
None of the above
Correct Answer :
A. Ensures the evaporator completely filled with refrigerant of the load
Related Questions
In larger industrial and commercial reciprocating compression systems, refrigerant widely used is
Ammonia
Carbon dioxide
Sulphur dioxide
R-12
Air refrigeration cycle is used in
Domestic refrigerators
Commercial refrigerators
Air conditioning
Gas liquefaction
The colour of the flame of halide torch, in case of leakage of Freon refrigerant, will change to
Bright green
Yellow
Red
Orange
The thermostatic expansion valve operates on the changes in the
Degree of superheat at exit from the evaporator
Temperature of the evaporator
Pressure in the evaporator
None of the above
A bootstrap air cooling system has
One heat exchanger
Two heat exchangers
Three heat exchangers
Four heat exchangers
A pressure gauge on the discharge side of a refrigerant compressor reads too high. The reasons will be
Lack of cooling water
Water temperature being high
Dirty condenser surface
All of these
Formation of frost on evaporator in refrigerator
Results in loss of heat due to poor heat transfer
Increases heat transfer rate
Is immaterial
Can be avoided by proper design
The boiling point of ammonia is
100°C
50°C
33.3°C
0°C
Short horizontal lines on pressure-enthalpy chart show
Constant pressure lines
Constant temperature lines
Constant total heat lines
Constant entropy lines
It is desired to condition the outside air from 70% relative humidity and 45° C dry bulb temperature to 50% relative humidity and 25° C dry bulb temperature (room condition). The practical arrangement will be
Dehumidification
Cooling and humidification
Cooling and dehumidification
Dehumidification and pure sensible cooling
The refrigerant widely used in domestic refrigerators is
Ammonia
Carbon dioxide
Sulphur dioxide
R-12
The comfort conditions in air conditioning are at (where DBT = Dry bulb temperature, and RH = Relative humidity)
25°C DBT and 100% RH
20°C DBT and 80% RH
22°C DBT and 60% RH
25°C DBT and 40% RH
The dry bulb temperature lines, on the psychrometric chart are
Vertical and uniformly spaced
Horizontal and uniformly spaced
Horizontal and non-uniformly spaced
Curved lines
In vapour compression refrigeration system, refrigerant occurs as liquid between
Condenser and expansion valve
Compressor and evaporator
Expansion valve and evaporator
Compressor and condenser
In a vapour absorption refrigeration system, the compressor of the vapour compression system is replaced by
Liquid pump
Generator
Absorber and generator
Absorber, generator and liquid pump
In a spray washing system, if the temperature of water is higher than the dry bulb temperature of entering air, then the air is
Heated and dehumidified
Heated and humidified
Cooled and humidified
Cooled and dehumidified
The reciprocating refrigerant compressors are very suitable for
Small displacements and low condensing pressures
Large displacements and high condensing pressures
Small displacements and high condensing pressures
Large displacements and low condensing pressures
In chemical dehumidification process,
Dew point temperature decreases
Wet bulb temperature decreases
Dry bulb temperature increases
All of these
Which of the following is not a desirable property of a refrigerant?
High risibility with oil
Low boiling point
Good electrical conductor
Large latent heat
The lowest temperature during the cycle in a vapour compression system occurs after
Compression
Expansion
Condensation
Evaporation
The curved lines on a psychrometric chart indicates
Dry bulb temperature
Wet bulb temperature
Dew point temperature
Relative humidity
The minimum temperature to which water can be cooled in a cooling tower is
Dew point temperature of air
Wet bulb temperature of air
Dry bulb temperature of air
Ambient air temperature
On the pressure-enthalpy diagram, condensation and desuperheating is represented by a horizontal line because the process
Involves no change in volume
Takes place at constant temperature
Takes place at constant entropy
Takes place at constant pressure
The boiling point of carbon dioxide is
-20.5°C
-50°C
-63.3°C
-78.3°C
Carbon dioxide is
Colourless
Odourless
Non-flammable
All of these
In aqua ammonia and Lithium bromide water absorption refrigeration systems, the refrigerants are respectively
Water and water
Water and lithium bromide
Ammonia and lithium bromide
Ammonia and water
The leakage in a refrigeration system using ammonia is detected by
Halide torch
Sulphur sticks
Soap and water
All of these
In vapour compression cycle, the condition of refrigerant is high pressure saturated liquid
After passing through the condenser
Before passing through the condenser
After passing through the expansion or throttle valve
Before entering the expansion valve
Which of the following cycles uses air as the refrigerant?
Ericson
Stirling
Carnot
Bell Coleman
The superheating in a refrigeration cycle
Does not alter C.O.P.
Increases C.O.P.
Decreases C.O.P.
None of these