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G192063 Pages:3

PART ‏تا‎

Answer any three full questions, each carries 10 marks.
With the support of a schematic and p-h diagram, explain the working of a two
stage vapour compression system with flash gas removal and inter-cooling.
Explain the desirable properties of refrigerants for vapour compression
refrigeration systems.
Explain with the help of schematic and p-h diagrams, the working of a two stage
evaporator vapour compression refrigeration system with single compressor.
With the support of a schematic diagram, explain the principle of working of
Electrolux refrigeration.
State any five applications of refrigeration. With the support of a neat sketch,
explain any one of the stated applications.
With a neat sketch explain any one type of water cooled condensers used in
vapour compression refrigeration systems.
With a neat sketch, explain the working of a flooded evaporator.

Describe the principle and working of thermostatic expansion valve.

PART C

Answer any four full questions, each carries 10 marks.
Define the terms (i) dry bulb temperature, (ii) absolute humidity (iii) wet bulb
temperature (iv) dew point temperature and (v) relative humidity
Determine the dew point temperature, absolute humidity, specific enthalpy and
specific volume of moist atmospheric air at mean sea level, if the dry bulb and
wet bulb temperatures are 28°C and 21°C, respectively. Show these properties
using a representative psychrometric chart.
100 m*/min of air at 20% relative humidity and 5°C is to be conditioned to 50%
relative humidity and 30°C. Determine the load on the air conditioning unit.
Also, determine the amount of water to be added or removed from the air during
the process.
What you mean by effective temperature in air conditioning? Describe a comfort
chart.
In an air conditioning plant, the air handling unit supplies 4500 m/min of dry air
which include 20% (by weight) fresh air at 40°C DBT and 27°C WBT. The re-

circulated air is at 25°C and 50% relative humidity. The air leaves the cooling

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