Refrigeration Engineering Question Paper of 3rd Semester AE(D) Download Previous Years Question Paper 1

S.B. Roll No. _____________

REFRIGERATION ENGINEERING

5th Exam/RAC/5407/0254/Dec’11

Duration 3 Hrs.

Section A

Q1. Do the following:

a. Most of the commercial refrigeration is produced by the evaporation of a liquid __________.

b. __________ is the ratio between the heat extracted and the work done.

c. The ratio of high temperature to low temperature for reversed carnot cycle refrigerator is 1:25. The COP will be __________.

d. In a domestic vapour compression refrigerator, the refrigerant commonly used is __________.

e. A domestic window type air conditioner capacity may be approx. __________ ton.

f. The refrigerant, commonly used in vapour absorption system, is __________ (water/ Freon)

g. For fixed pressure ratio the isentropic compression work is the lowest for __________ (R-11/R-12)

h. __________ refrigerants are those working mediums or heat carries which directly take part in the refrigeration system (primary / secondary).

i. Air refrigeration cycle is used in __________ (air conditioning refrigerators)

j. The cooling system used for supersonic aircrafts and rockets is __________ (regenerative / boot– strap)

Section B

Note: Attempt any five questions

Q2 i. Define actual COP and theoretical COP?

ii. State merits and demerits of an air refrigeration system.

iii. Explain briefly the term ‘Total Volumetric efficiency’?

iv. What is simple vapour absorption system? State how its efficiency can be improved?

v. Define ‘Refrigerant”. How are refrigerants classified?

vi. State the limitations of reversed Carnot cycle?

vii. Enumerate important refrigeration applications.

Section C

Note: Attempt any three questions

Q3. Derive an expression for COP for an air refrigeration system working on reversed Brayton Cycle.

Q4. Draw a neat diagram of dithiumbromide water absoption refrigeration system and explain its working? List out the major fields of application?

Q5. Discuss the physical and thermodynamic properties of the following refrigerants and how the leaks are detected in each case

a. R-11

b. R-12

c. R-22

Q6. A reversed Carnot cycle is used for heating and cooling purpose. If the work supplied is 9.5 kw and COP is 3.6 for cooling find.

a. T2/T1

b. The refrigerating effect in tonner of refrigeration

c. COP for heating