REFRIGERATION & AIR.CONDITIONING


1 Answer any two of the following :
(a) List some applications of air conditioning .
(b) With a simple sketch explain the working of a vapour compression refrigeration system.
(c) Explain briefly some applications for reciprocating and centrifugal compressors.

2 Answer any two of the following :
(a) What is the significance of the Carnot refrigerator ?
What are the practical difficulties in devising a Carnot refrigerator ?
(b) What is a Cascade Refrigeration System ? Compare this system with multistorage compression and evaporation

3 What is the working substance in air conditioning? Would you call it a pure substance ? How do you calculate its molecular mass ?

4 Answer any two of the following:
(a) Define
(i) Dew point temperature
(ii) Dry bulb temperature
(iii) Wet bulb temperature
(b) What do you understund by marine relrigeration and how is it different from truck refrigeration ?
(c) It is proposed to use a reversed Carnot engine as a refrigerator. The unit consumes
10 kW power. If the COP is 3.5, determine the refrigeration capacity of the unit.

5 Answer any two of the following::
(a) What are the important Factors Which govern the choice of a r?frigerant?
(b) How do tho following two.factors inflicnco the performance of a vapour-compressioni refngeration system?
(1) Suction vapour- superheat
(2) Liquid subcooling

6 What are the difierent types of compressors ued in industry ? write in short working system of any one type of compressor?

7 Define refrigerant. State desirable chemical propeeties of a good refrigetant?

8 What are the differences between:
(i) Refrigertion and Heat pump system
(ii) Natural convection condenser and Forced air circulation condenser
(iii) Primary and secondary refrigerants

9 Write in brief on Comfort Air-conditioning?

10 What do you understand by martine refrigeration and how is it different from truck refrigeration?

11 What are the parameters required to be controlled for air conditioning ?

12 How is summer air conditioning different from winter air conditioning ?

13 What is the function of condenser in refrigeration system ? Write short notes on air cooled condenser.

14 Define primary refrigerant. State thermodynamic properties of a good refrigerant?

15 What are the factors contributing to food spoilage ?

16 What are the different types of refrigeration systems used for refrigeration trucks and trailers ?

17 How do the parts of an ammonia absorption system compare with those of a vapourcompression system ?

18 What is ton of refrigeration ? List some applications of air conditioning.

19 What do you understand by transport refrigeration ? What types of refrigeration systems are used for transport refrigeration ? Explain with examples.

20 What are the various factors which are contributing to food spoilage ? List the
causes of food spoilage.

21 What is refrigerating effect ? How refrigeration helps in the preservation of
food products ?

22 What are the temperature and humidity conditions required for the comfort air
conditioning ? Explain.

23 What is condenser ? What are the various types of condensers ? Explain working principle of water cooled condenser.

24 What is a refrigerant ? List some common refrigerants. Also describe the various desirable properties of Refrigerants.

25 What is a ceased refrigeration system ? Compare this system with multistage compression and evaporation systems.

26 What are the conditions for Highest COP. Explain the effects on P-h diagram?
27 What are different types of condensers used in refrigeration ? Explain the working of Evaporative condenser.


28 What are the different types of Evaporators ? Explain in short any one type of Evaporator.

29 Discuss the desirable thermodynamic, chemical and physical properties of
refrigerants.?

30 What are different steps in food preservation ?

31 Describe various types of Freezers.?