27-08-2016, 09:54 AM
Refrigeration and Air Conditioning 4-1 Set-1 (K).doc (Size: 346 KB / Downloads: 10)
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Define the terms unit of refrigeration and COP. [8] (Unit-I, Topic No. 1.1)
With the help of a neat sketch explain the air conditioning system used in aircrafts. [7] (Unit-I, Topic No. 1.4)
With the help of a neat sketch explain the working of a simple vapour compression refrigeration system.
[7] (Unit-II, Topic No. 2.1)
In an ammonia vapour compression refrigerator, the temperature of refrigerator is – 10°C. The vapour is
condensed in a condenser at 30°C. Find the theoretical C.O.P of the cycle when the vapour at the end of
compression is 0.9 dry. Take latent heat of NH3 AT 30° C = 1442 kJ/kg, specific heat of liquid NH3 = 4.7 kJ/kg. [8]
(Unit-II, Topic No. 2.3)
Derive an expression for volumetric efficiency of a reciprocating compressor taking clearance volume into
consideration. [8] (Unit-III, Topic No. 3.1)
With a neat sketch explain the working of thermostatic expansion valve. [7] (Unit-III, Topic No. 3.4)
Describe the properties of ideal refrigerant – absorbent combination. [6] (Unit-III, Topic No. 3.5)
Derive an expression to find out the coefficient of performance of the absorption refrigeration system.
[9] (Unit-IV, Topic No. 4.1)
What are the advantages and disadvantages of steam jet refrigeration system over other types of refrigeration
system. [7] (Unit-V, Topic No. 5.1)
Derive the expression for finding out the quantity of steam required per ton of refrigeration in steam jet
refrigeration. [8] (Unit-V, Topic No. 5.1)
Why ventilation is required? Explain why different ventilation standards for different purposes are
recommended? [8] (Unit-VI, Topic No. 6.3)
An air-water vapour mixture enters a heater-humidifier unit at 8° C, 110 kPa, 45% RH. Find,
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The relative humidity at the outlet, and
(ii) The rate of heat transfer to the unit. [7] (Unit-VI, Topic No. 6.1)
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Write the term “Effective temperature” and explain its importance in air conditioning system. Describe the factors
which affect effective temperature m3/min of moist air at 15° C DBT and 13° C WBT are mixed with 12 m3/min. An moist
air at 25° C DBT and 18° C WBT. Determine DBT and WBT of the mixture assuming the barometric pressure is one
atmospheric. Use pychrometric chart. [15] (Unit-VII, Topic No. 7.1)