Download PTU (Punjab Technical University) B.Tech (Bachelor of Technology) / BE (Bachelor of Engineering) 2021 January ME 7th Sem 71995 Refrigeration And Air Conditioning Previous Question Paper
Roll No.
Total No. of Pages : 02
Total No. of Questions : 18
B.Tech. (ME) (2012 Onwards) (Sem.?7)
REFRIGERATION AND AIR CONDITIONING
Subject Code : BTME-802
M.Code : 71995
Time : 3 Hrs. Max. Marks : 60
INST RUCT ION TO CANDIDAT ES:
1 .
SECT ION-A is COMPULSORY cons is ting of TEN questions carrying TWO marks
each.
2 .
SECT ION-B c ontains F IVE questions c arrying FIVE marks eac h and s tud ents
have to atte mpt any FOUR q ues tions.
3 .
SECT ION-C contains THREE questions carrying T EN marks e ach and s tudents
have to atte mpt any T WO questio ns.
SECTION-A
Write briefly :
1.
What is meant by refrigeration effect?
2.
Define coefficient of performance.
3.
How effectiveness of a refrigeration system is measured?
4.
What is sub-cooling?
5.
What is the function of a flash intercooler?
6.
What is the function of absorber?
7.
What is an azeotrope?
8.
What are the factors affecting comfort air conditioning?
9.
Why condensers are used in an air conditioning system?
10. Define wet bulb temperature.
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SECTION-B
11. A refrigerator working on Bell - Coleman cycle operates between pressure limits of
1.05 bar and 8.5 bar. Air is drawn from the cold chamber at 10? C, compressed and then it
is cooled to 30? C before entering the expansion cylinder. The expansion and compression
follows the law pv1.3 = constant. Determine the theoretical C.O.P. of the system.
12. Explain how an actual cycle differs from a theoretical vapour compression cycle.
13. Explain a two stage compression system with liquid intercooler.
14. What are eco-friendly refrigerants? Discuss the action plan to reduce ecological hazards.
15. Explain the working of steam jet refrigeration system with the help of a line diagram.
SECTION-C
16. Draw a neat diagram of lithium bromide water absorption system and explain its working.
17. Explain the air conditioning system required for winter season with the help of a sketch.
18. A two stage compression ammonia refrigerating system with water and flash intercooling
and water sub-cooling operates between overall pressure limits of 13.89 bar and 1.9 bar.
The flash intercooler pressure is 4.97 bar. The temperature of refrigerant leaving the water
intercooler and the water sub-cooler is limited to 30?C. If the load is 10 TR, find :
a) Coefficient of performance of the system.
b) Power required to drive each compressor.
c) Swept volume for each compressor assuming the volumetric efficiency for both the
compressor as 80%.
NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.
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This post was last modified on 26 June 2021