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Select a suitable commercially available refrigerant with proper designation, for
the following cases with due justifications.

1) 23 609 effective halogen free refrigerant for ice plants

ii) Eco-friendly HFC refrigerant with low Ozone Depletion Potential

iii) Domestic refrigerator with hermetically sealed compressor
Write a short note on secondary refrigerants
The specific humidity of atmospheric air at 28°C DBT and 1 atm pressure is
0.016 kg/kg dry air. Using suitable correlations (not psychrometric chart),
determine partial pressure of water vapour, relative humidity, dew point
temperature, specific enthalpy and vapour density.
Determine the load required to raise 0.5 077/5 of air at 10°C DBT and 80% RH to
30°C DBT. What would be the relative humidity and WBT of air in its final
condition? Represent the process in psychrometric chart, duly indicating the
salient properties.

PART C
Answer any four full questions, each carries 10 marks.

A vapour compression cycle using R-22 operates at condensing temperature of

36°C and evaporating temperature of -10°C. Refrigeration capacity is 15 TR.
Determine the following.

1. Mass flow rate of refrigerant

2. Compressor power

3. Heat rejected at the condenser

4. Actual COP
Discuss the working of a simple NH3-H20 vapour absorption refrigeration
system (VARS) with a neat schematic. List any two advantages of VARS.
Calculate the COP of vapour absorption refrigeration system with generator
temperature=150°C, Absorber temperature=30°C, Condenser temperature=30°C
and Evaporator temperature= 10°C
Discuss the working of a winter air conditioning system with a neat schematic
and represent the process on a typical psychrometric chart.

Define the following air conditioning parameters and discuss their relevance.

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