Refrigeration and Air Conditioning, Question Paper of M.Tech 6 Semester, Download Previous Years Question Paper 9

REFRIGERATION AND AIR CONDITIONING

6^th Exam/ Mech/5313/Dec’ 03

Duration 3  Hrs.                                                                                  M.Marks:  75

SECTION A

Qt. a) Fill in the blanks:

l) A simple air-cooling system is good for - flight speeds.

ii} in a domestic vapour compression refrigerator. the refrigerant commonly used is

iii) The optimum temperature at which most enzymes act’ rapidly is-about

iv) The wet bulb depression is zero, when relative humidity is equal to

v) The sensible heat factor for auditorium cinema Hail is generally kept as

b) Write True-or False.

i)  The C.O.Ii3. is the reciprocal of the efficiency of a heat engine.

ii) The expansion valve in a refrigerator controls the flow of refrigerant.

iii) During sub-cooling. Sensible heat from a liquid refrigerant is removed.

iv) The absolute humidity is the mass of water vapor present in 1 Kg of dry air.

v}- A low wet bulb temperature indicates very high humidity.

Section B

02. Attempt any five questions:

a) Discuss the advantage of the dense air refrigerating system over an open Air refrigerating system.

b) Why in practice a throttle valve is used ln vapor compression refrigerator system rather than expansion cylinder to reduce pressure between the condenses and the evaporator.

c) Name the various methods of leak detection and explain one of them.

d) What are the desirable properties of an ideal refrigerant? 5

e) When 'is dehumidification of air is necessary and how it is achieved?

t) What are the merits and demerits of vapour absorption system?

g) Describe in brief. Functions and constructional details of solenoid valve.

Section C

03 Attempt pt any three 3 questions:

i. Explain with neat sketch the working of central system of Air-conditioning

ii. Draw