Refrigeration and Air conditioning — Summer 2025

State important applications of refrigeration system?

Explain ice plant with a neat sketch?

Arefrigeration machine using air as working fluid and working on closed Bell Coleman cycle operating under the following conditions: Refrigeration temperature = 150 K, Cooler temperature = 300 K. The air temperature at th entry of the refrigerator is 40 Kless than the refrigerator temperature. Pressure in the refrigerator = 1 bar, Calculate 1) Refrigeration effect 2) Net work 3) COP of the machine 4) Cooler temperature. Assume expansion and compression are isentropic

What are desirable characteristics of absorbent and absorbent refrigerant combination in vapour absorption refrigeration cycle?

Draw thermodynamic model of vapour absorption system and Derive equation of COP of ideal vapour absorption system.

State the name of different types of system used for cooling of aircraft cabin. Explain with schematic diagram Bootstrap air Refrigeration system.

Explain working of Li-Br vapour absorption refrigeration system with neat sketch.

Write a short note on infiltration?

Discuss thermodynamic and physical properties of ideal refrigerant.

Mention the limitations of Simple vapour compression refrigeration Cycle. Explain compound compression with flash chamber but without intercooler with system diagram and P-Hdiagram.

Categorize different types of loads acting in restaurants.

State different types of compressors used in refrigerators. Also explain flooded type evaporator with a neat sketch?1

State the name of Different type’s evaporative devices used in refrigeration system Explain Thermostatic expansion valve.

Define volumetric efficiency, isothermal efficiency, and adiabatic efficiency of compressor.

Define human comfort and explain any four factors which affect it?

The main air supply duct of an air conditioning system is 880 mm x 660 mm in cross section, and carries 330 m3/min of standard air. It branches into two ducts of cross section 660 mm x 550 mm and 660 mm x 440 mm. If the mean velocity in the larger branch is 420 m/s, determine the following: (1) Mean velocity in the main duct and the smaller branch (2) Mean velocity pressure in each duct.

Define specific humidity, dew point temperature and wet bulb depression.

Explain importance of site survey for load calculation.

What is effective temperature? What factors affect effective temperature and explain its significance in design of air- conditioning systems

Note down the factors affecting solar heat gain through wall.

Explain equal friction method of duct sizing for air conditioning?

With line diagram explain Central Air-conditioning system of any multi storey building.

Write a short note on filters.

Explain following terms with respect to fan

Total fan pressure ii) Dynamic pressure

What are different methods used for design of the ducts and explain advantages of each over other