The reduced ambient air cooling system has
One cooling turbine and one heat exchanger
One cooling turbine and two heat exchangers
Two cooling turbines and one heat exchanger
Two cooling turbines and two heat exchangers
Correct Answer :
C. Two cooling turbines and one heat exchanger
Related Questions
A vapour absorption refrigerator uses __________ as a refrigerant.
Water
Ammonia
Freon
Aqua-ammonia
In vapour compression cycle the condition off refrigerant is dry saturated vapour
After passing through the condenser
Before passing through the condenser
After passing through the expansion or throttle valve
Before entering the compressor
The wet bulb temperature during sensible heating of air
Remains constant
Increases
Decreases
None of these
Pressure of water vapour is given by
0.622 Pv/ (Pb - Pv)
μ/[1 - (1 - μ) (Ps/Pb)]
[Pv (Pb - Pd)]/ [Pd (Pb - Pv)]
None of these
Which of the following statement is wrong?
The performance of the vapour compression refrigerator varies considerably with both vaporising and condensing temperatures.
In vapour compression cycle, the useful part of the heat transfer is at the condenser.
In ammonia-hydrogen (Electrolux) refrigerator, no compressor, pump or fan is required.
The effect of under-cooling the liquid refrigerant is to decrease the coefficient of performance.
In a vapour compression refrigeration system, a throttle valve is used in place of an expander because
It considerably reduces mass of the system
It improves the C.O.P., as the condenser is small
The positive work in isentropic expansion of liquid is very small
It leads to significant cost reduction
The bank of tubes at the back of domestic refrigerator is
Condenser tubes
Evaporator tubes
Refrigerant cooling tubes
Capillary tubes
A valve which maintains a constant degree of superheat at the end of the evaporator coil, is called
Automatic expansion valve
High side float valve
Thermostatic expansion valve
Low side float valve
The alignment circle is marked on the psychrometric chart at
20°C DBT and 50% RH
26°C DBT and 50% RH
20°C DBT and 60% RH
26°C DBT and 60% RH
In order to collect liquid refrigerant and to prevent it from going to a ________, a device known as accumulator is used at the suction of compressor.
Compressor
Condenser
Expansion valve
Evaporator
Refrigeration in aeroplanes usually employs the following refrigerant
CO2
Freon-11
Freon-22
Air
If the evaporator temperature of a plant is lowered, keeping the condenser temperature constant, the h.p. of compressor required will be
Same
More
Less
More/less depending on rating
The relative coefficient of performance is equal to
(Theoretical C.O.P.)/ (Actual C.O.P.)
(Actual C.O.P.) /(Theoretical C.O.P.)
(Actual C.O.P.) × (Theoretical C.O.P.)
None of these
The ratio of heat extracted in the refrigerator to the work-done on the refrigerant is called
Coefficient of performance of refrigeration
Coefficient of performance of heat pump
Relative coefficient of performance
Refrigerating efficiency
In a reversed Brayton cycle, the heat is absorbed by the air during
Isentropic compression process
Constant pressure cooling process
Isentropic expansion process
Constant pressure expansion process
If a heat pump cycle operates between the condenser temperature of +27°C and evaporator temperature of -23°C, then the Carnot COP will be
0.2
1.2
5
6
The refrigerant after condensation process is cooled below the saturation temperature before throttling. Such a process is called
Sub-cooling or under-cooling
Super-cooling
Normal cooling
None of these
The bypass factor of a cooling coil decreases with
Decrease in fin spacing and increase in number of rows
Increase in fin spacing and increase in number of rows
Increase in fin spacing and decrease in number of rows
Decrease in fin spacing and decrease in number of rows
The vertical and uniformly spaced lines on a psychrometric chart indicates
Dry bulb temperature
Wet bulb temperature
Dew point temperature
Specific humidity
Chaperon equation is applicable for registration at
Saturation point of vapour
Saturation point of liquid
Sublimation temperature
Triple point
The wet bulb temperature at 100% relative humidity is ________ dew point temperature.
Same as
Lower than
Higher than
None of these
The specific humidity during heating and humidification process.
Remains constant
Increases
Decreases
None 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
A Bell Coleman refrigerator working on dense air system as compared to open air system, for the same range of temperature, results in ________ power per tonne of refrigeration.
Same
Lower
Higher
None of these
The evolution of heat of solution takes place in ammonia absorption plant when
Ammonia vapour goes into solution
Ammonia vapour is driven out of solution
Lithium bromide mixes with ammonia
Weak solution mixes with strong solution
The COP of a domestic refrigerator
Is less than 1
Is more than 1
Is equal to 1
Depends upon the make
An important characteristic of absorption system of refrigeration is
Noisy operation
Quiet operation
Cooling below 0°C
Very little power consumption
The colour of the flame of halide torch, in case of leakage of Freon refrigerant, will change to
Bright green
Yellow
Red
Orange
For ammonia refrigerating systems, the tubes of a shell and tube condenser are made of
Copper
Aluminium
Steel
Brass
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