Refrigeration and Air Conditioning, Question Paper of M.Tech 6 Semester, Download Previous Years Question Paper 5

REFRIGERATION AND AIR CONDITIONING

6^th Exam/ Mech/ 5313/ May 08

Duration: 3 Hrs.                                                                             Max. Marks: 75

Note: Attempt all questions.

Q1 Do as directed:

i. The coefficient of performance is always___________ one.

ii. Air refrigerator works on

a. Carnot cycle    b. Rankine cycle

c. reversed Carnot- cycle d. Bell-Coleman cycle

iii. The coefficient of performance of vapour compression refrigeration system is quite

___________as compared to air refrigeration system.

a. low                                                             b. high

iv. in a domes-tic vapour compression refrigerator. The refrigerant commonly used is.

a. CO₂                                                            b. ammonia

c. Freon-12                                                     d. all of these

v. The freezing point of R-12 is

a. -85.6^o C                                                     b. -95.2^oC

c. -107.7^oC                                                   d. -157.5^oC

vi. In larger industrial and commercial reciprocating compression systems, the refrigerant widely used is

a. ammonia                                                              b. carbon dioxide

c. sulphur dioxide                                                   d. R-12

vii. The thermostatic expansion value is also called

a. constant pressure value                                  b. constant temp value

c. constant super heat value                               d. none of these

Viii. The vertical and uniformly spaced lines on a psychometric chart indicates

a. dry bulb temperature                                      b. wet bulb temperature

c. dew point temperature                                   d. specific humidity

ix. The process generally used in winter air conditioning to warm and humidity the air. is called

a. humidificatlon                                                    b. dehumidification

c. heating and 'humidification                            d. cooling and dehumidification

x. The heat production from a normal healthy man when asleep is about

a. 20 watts                                                               b. 40 watts

c. 60 watts                                                               d. 30 watts

Q2 Attempt any five questions.

i. Draw a neat diagram with labeling of a year round air conditioning system.

ll. Differentiate between wet bulb temperature and dry bulb temperature.

iii. Explain humidification and dehumidification processes.

iv. Write down various applications of air-conditioning.

v. Explain solenoid value.

vi. Write down the properties and applications of R12 refrigerant.

vii. Explain the working of Bell-Coleman refrigerator. Drive the equation for its COP.

Q3 Attempt any two questions.

i. Describe briefly the factors that affect human comfort.

ii. Explain the properties and applications of R22 and NH3 refrigerant.

iii. Explain with neat diagram the psychometric chart. Write down its uses.

iv. Explain the principle of evaporative cooling. Give the layout of an ice plant.

04 Explain the function of oil separation.