Reg No.:

00000ME405121902

Pages: 3

Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

Seventh Semester B.Tech Degree Examination (Regular and Supplementary), December 2020

Max. Marks: 100

b)
2 2)
b)
3 a)
b)

Course Code: ME405

Course Name: Refrigeration and Air Conditioning

Use of Refrigeration and Air Conditioning data book is permitted
PARTA
Answer any three full questions, each carries 10 marks.
Define the terms: (i) Refrigeration (ii) Coefficient of Performance and (iii) Ton
of Refrigeration. State the major applications of refrigeration
A Carnot refrigerator works between temperature limits of 37°C and -13°C.
Find the Carnot COP. Also determine the amount of ice that will be produced
per kWh at -13°C from water at 27°C using this refrigerator.
Explain with the support of schematic and T-S diagrams the working of
regenerative aircraft refrigeration system.
An air refrigerator working on reversed Brayton cycle gets compressor inlet air
at 1.2 bar and the pressure ratio is 3.75. Determine the theoretical Brayton COP
and Carnot COP, if the compression and expansion processes are reversible
adiabatic. Assume that the cold chamber temperature is 10°C and ambient
temperature is 30°C.
Describe any one refrigeration technique for the production of very low
temperature using a neat diagram.
A R12 refrigerator operates between temperatures of 35°C and -15°C, for the
condenser and evaporator, respectively. The system is provided with a liquid-
vapour regenerative heat exchanger with the temperature of refrigerant vapour
leaving the heat exchanger is at 15°C. Determine the COP of the system. Also,
determine the COP of the system without the liquid-vapour regenerative heat
exchanger. Assume that the cycle is simple saturated without the regenerative

heat exchanger.

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Duration: 3 Hours

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