REFRIGERATION AND AIRCONDITIONING DIPLOMA IN MECHANICAL ENGINEERING 6TH SEM
Courtly:dte board
DEPARTMENT OF TECHNICAL EDUCATION
DIPLOMA COURSE IN MECHANICAL ENGINEERING
SIXTH SEMESTER
MODEL
QUESTION PAPER
REFRIGERATION AND AIRCONDITIONING
Time: 3Hrs Max
marks: 100
Note:
1.Part-I is compulsory
2. Answer any six full questions
from Part-II, Part-III, and Part-IV
Choosing at least two from each section
PART- I
1 A) Fill
in the blanks with appropriate words:-
1X5
I)
The refrigerant used in dairy refrigeration is ______________.
ii)
The air refrigerator working on
_____________cycle
iii)
______________ unit of refrigeration
iv)
The automatic expansion valve is used to control the
______________refrigerant.
v)
The motor and compressor mounted on the same casing
in_______________compressor
B) Write a note steam jet
refrigeration 5
PART-II
2
a) Define the following terms w.r.t refrigeration
i) Refrigerating effect ii)
C.O.P 4
b) Explain with block diagram Carnot
refrigeration Cycle. 5
c) State the advantage and disadvantages of
air refrigeration system.
6
3 a) Explain with flow
diagram of working of Vapour compression
cycle . 8
b) A Refrigeration
working on Bell-Coleman cycle operates between pressures
limits of 1 bar and 8.5 bar. Air is drawn from the cold chamber at 100C and
it is cooled to 300C before entering the expansion follow the law PV ^ 1.35 = C
7
Determine theoretical COP of the system
4
a) Explain with the help of TS and HS diagrams the working of
vapour compression 5
Refrigeration system.
b) Explain the effects of
super heating and under cooling. 5
c) Differentiate between vapour absorption and vapour
compression refrigeration system 5
PART-III
5 a) State the Advantages
of air cooled and water cooled condensers 4
b) Sketch and explain hermitically sealed compressor 6
c) Differentiate
between natural and forced cooling system
5
6 a) Describe forced
convection types
Evaporators .
4
b) State the properties
of good refrigerants.
6
c) Sketch and explain thermostatic
expansion valve 5
7 a)
Explain the working of high side float
valve 5
b) State the function of solenoid
valve. 5
c) Describe briefly dairy refrigeration 5
PART-IV
8
a) Explain with schematic diagram water
cooler 5
b) Explain Psychometric chart & its use 5
c) Describe briefly psychometric process
a) Sensible heating b) Adiabatic
saturation
5
9 a) Explain installation procedure of
refrigeration systems . 5
b) State the factors affecting Air conditioning
5
c) Describe briefly window air conditioner 5
10 Write short note on any three of the following 5x3=15
i) Tools used in refrigeration and Air
conditioner installation r
ii) Packaged air
conditioner
iii) Cold storage
iv) Evaporator pressure regulator
v) Air refrigeration
system
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