1.a. In HFC-134a 1TR ejector refrigeration system, the motive vapour is saturated at $80^{\circ} \mathrm{C}$ has following data:

a) Temperature of in the evaporator $=-5^{\circ} \mathrm{C}$

b) The pressure at which the condenser is operated 10 bar

c) Nozzle efficiency $=86 \%$

d) Entrainment efficiency $=64 \%$

e) Compression efficiency $=80 \%$

f) Quality of refrigerant at the beginning of compression =0.96

Determine the following

i) Mass of motive fluid required per kg of secondary fluid

ii) The quantity of secondary fluid

iii) Refrigerating effect per kg

iv) COP of the system

2.a. Explain parallel compression transcritical system:

2.b. Discuss classification of cooling tower.

3. A two cylinder single acting reciprocating compressor with 5$\%$ clearance is used in a 22 refrigeration cycle to take refrigeration capacity of 7.2 $\mathrm{TR}$ at $5^{\circ} \mathrm{C}(3.6 \mathrm{bar})$ refrigeration temp. $\& 40^{\circ} \mathrm{C}(9.6 \mathrm{bar})$ condensing temperature.The compressor index is 1.15 . The speed of the piston is limited to 3 $\mathrm{m} / \mathrm{s}$ . Take $\mathrm{LD}=0.8$ specific volume as 0.0525 $\mathrm{m}^{3} / \mathrm{kg.}$

Determine :

a) power

b) Volumetric efficiency

c) COP

d) Bore \& stroke

e) RPM

4.a. Draw various arrangements of suction line.

4.b. Discuss the various methods of capacity controls of centrifugal compressor.

5.a. Write a short note on "thermodynamics of human body" and explain comfort-discomfort diagrams with neat sketch.

5.b. The following table shows the measurements made at 9 points in the occupied zone of an air conditioned building. Evaluate the design parameters of the air distribution system. Consider Supply air temperature as $17^{\circ} \mathrm{C}$ and exhaust temperature as $25^{\circ} \mathrm{C}$

6.a. Discuss types of air distribution devices.

6.b. State factors affecting thermal comforts.

7.a. A 25 $\mathrm{cm}$ thick wall is exposed to the periodic temperature and incident radiant variation on an hourly basis between 7 $\mathrm{am}$ and 6 $\mathrm{pm}$ is given in the table. Determine average heat gain of the room per unit area of the wall. The outdoor maximum and minimum temperatures are $40^{\circ} \mathrm{C}$ and $22^{\circ} \mathrm{C}$ respectively The outside and inside design temperatures are 40 and $25^{\circ} \mathrm{C}$ respectively. What is the maximum heat gain and time of maximum heat gain from the wall?

Density of material, $\rho=2400 \mathrm{kg} / \mathrm{m}^{3}$

Thermal conductivity, $\mathrm{k}=1.5 \mathrm{W} / \mathrm{mK}$

Outside wall coefficient, $\mathrm{h}=23 \mathrm{W} / \mathrm{m}^{2} \mathrm{K}$

Inside wall coefficient, $\mathrm{h}=7 \mathrm{W} / \mathrm{m}^{2} \mathrm{K}$

7.b. Write a short note on

i) Sol-air temperature

ii) Air Spaces.

8.a. Explain Energy Conservation Building Code.

8.b. Explain the term "Decrement factor & time lag".

9.a. Explain with schematic diagram Indirect Evaporative-Cooling Air Conditioning Systems.

9.b. Draw and explain water-to-water heat pump circuit

10.a. Write a short note on "Clean Room".

10.b. Explain Hybrid Desiccant air-conditioning system.