11-06-2013, 11:52 AM
SEMESTER EXAMINATIONS FOR REFRIGERATION & A/C EQUIPMENTS & CONTROL
REFRIGERATION & AC.pdf (Size: 32.39 KB / Downloads: 19)
Answer any five questions
All questions carry equal marks
1.a) Derive an expression for volumetric efficiency of reciprocating compressor. Explain with PU diagram.
b) What are the factors affecting the performance of reciprocating compressor? Explain in detail.
2.a) What is the method of lubrication for compressors? Briefly explain.
b) Briefly explain the common required properties of lubricating oil in refrigeration system.
3.a) What is maintenance of cooling towers? Briefly explain the different types of maintenance techniques.
b) Explain the following
i) Evaporative condenser
ii) Cooling ponds.
4.a) What is the difference between Natural convection and Forced Convection Evaporators? Explain clearly.
b) Sketch and explain the working of Secondary Evaporators. Name the various parts.
5.a) What is low-side float system and high-side float system? Explain with neat sketches.
b) Briefly explain the suction piping arrangements for refrigeration system.
6.a) What is the capacity control of centrifugal compressors? Explain in detail.
b) Briefly discuss compressor surging.
7.a) Sketch and explain the working of automatic defrosting.
b) What are the leakages in refrigeration system? What are the remedies?
8. Write short notes on:
a) Rotary compressors
b) Water treatment in expansion devices.