Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2019 Summer 8th Sem Old 181901 Refrigeration And Air Conditioning Previous Question Paper
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VIII (OLD) EXAMINATION ? SUMMER 2019
Subject Code: 181901 Date: 15/05/2019
Subject Name:Refrigeration And Air-Conditioning
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) Discuss the effect of following on the performance of a vapour compression
system
i. Effect of suction pressure
ii. Effect of delivery pressure
iii. Effect of superheating
iv. Effect of sub-cooling of liquid.
07
(b) An air refrigeration system operating on Bell-Coleman cycle, takes in air from a
room at -6
0
C and compresses it from 1.04 bar to 6.2 bar. The index of
compression being 1.26. The compressed air is cooled to 25
0
C. The ambient
temperature is 18
0
C. Air expands in an expander where index of compression is
1.36. Determine
i. C.O.P of the system
ii. Quantity of air circulated per minute for production of 1500 kg of ice per
day at 0
0
C from water at 15
0
C.
iii. Capacity of the plant.
07
Q.2 (a) Enumerate desirable properties of an ideal refrigerant. 07
(b) Explain Lithium-Bromide vapour absorption system with neat sketch. 07
OR
(b) Explain Boot strap air refrigeration system with neat sketch. 07
Q.3 (a) State the principle of steam jet refrigeration system. Write at least three
advantages and three disadvantages of steam jet refrigeration over other systems
07
(b) Give detailed classification of compressors used in refrigeration and explain any
one rotary compressor.
07
OR
Q.3 (a) Enlist various types of expansion valves used in refrigeration and explain any one
with neat sketch.
07
(b) Explain compound compression with multiple expansion valves and flash
intercooling system.
07
Q.4 (a)
Define following term related to psychrometry
i. Saturated air
ii. Dry bulb temperature
iii. Relative humidity
iv. Specific humidity
v. Dew point temperature
vi. Sensible heat factor
vii. By-pass factor.
07
(b) Enumerate and explain the components of cooling load estimate. 07
OR
Q.4 (a) Discuss the factors affecting human comfort. 07
(b) Atmospheric air at 15
0
C DBT and 30% RH passes through a furnace and through
a humidifier, in such a way that the final DBT is 32
0
C and 40% RH. Determine
07
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1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VIII (OLD) EXAMINATION ? SUMMER 2019
Subject Code: 181901 Date: 15/05/2019
Subject Name:Refrigeration And Air-Conditioning
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) Discuss the effect of following on the performance of a vapour compression
system
i. Effect of suction pressure
ii. Effect of delivery pressure
iii. Effect of superheating
iv. Effect of sub-cooling of liquid.
07
(b) An air refrigeration system operating on Bell-Coleman cycle, takes in air from a
room at -6
0
C and compresses it from 1.04 bar to 6.2 bar. The index of
compression being 1.26. The compressed air is cooled to 25
0
C. The ambient
temperature is 18
0
C. Air expands in an expander where index of compression is
1.36. Determine
i. C.O.P of the system
ii. Quantity of air circulated per minute for production of 1500 kg of ice per
day at 0
0
C from water at 15
0
C.
iii. Capacity of the plant.
07
Q.2 (a) Enumerate desirable properties of an ideal refrigerant. 07
(b) Explain Lithium-Bromide vapour absorption system with neat sketch. 07
OR
(b) Explain Boot strap air refrigeration system with neat sketch. 07
Q.3 (a) State the principle of steam jet refrigeration system. Write at least three
advantages and three disadvantages of steam jet refrigeration over other systems
07
(b) Give detailed classification of compressors used in refrigeration and explain any
one rotary compressor.
07
OR
Q.3 (a) Enlist various types of expansion valves used in refrigeration and explain any one
with neat sketch.
07
(b) Explain compound compression with multiple expansion valves and flash
intercooling system.
07
Q.4 (a)
Define following term related to psychrometry
i. Saturated air
ii. Dry bulb temperature
iii. Relative humidity
iv. Specific humidity
v. Dew point temperature
vi. Sensible heat factor
vii. By-pass factor.
07
(b) Enumerate and explain the components of cooling load estimate. 07
OR
Q.4 (a) Discuss the factors affecting human comfort. 07
(b) Atmospheric air at 15
0
C DBT and 30% RH passes through a furnace and through
a humidifier, in such a way that the final DBT is 32
0
C and 40% RH. Determine
07
2
i. Heat and moisture added to the air.
ii. Sensible heat factor of the process.
Q.5 (a) Enumerate various methods of air-conditioning duct design and explain in detail
the ?Equal friction method?.
07
(b) With neat sketch explain working of an Ice Plant. 07
OR
Q.5 (a) Explain following terms with respect to fan
i. Static fan pressure
ii. Dynamic fan pressure
iii. Specific speed
iv. Static fan efficiency
07
(b) Classify air conditioning systems. Explain Central air conditioning system with
a neat sketch
07
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This post was last modified on 20 February 2020