1) Write down the name of four significant properties of a good refrigerant.
2) Write down the difference between air conditioning and refrigeration.
3) Describe the function of throttling valve in vapour compression refrigeration system.
4) In vapour compression refrigeration system, where the highest temperature will take place?
5) Vapour absorption system can use low-grade heat energy in a generator. Is true of false?
6) Write down the name of any four commonly used refrigerants.
7) Describe unit of Refrigeration in detail.
8) Single stage single acting air compressor is used to compress air from 1.013 bar and 25° C to 7 bar according to law PV1.3= C. Bore and stroke of the cylinder are 120mm and 150mm respectively. Compressor runs at 250 rpm. If clearance volume of cylinder is 5% of stroke volume and mechanical efficiency of compressor is 85%, find out volumetric efficiency, power, and mass of air delivered per minute.
9) Two stage singe acting air compressor compresses 2m3 airs from 1 bar and 20° C to 15 bar. Air from low pressure compressor is cooled to 25°C in an intercooler. Compute the minimum power required to run compressor if compression follows PV1.25=C and compressor runs at 400rpm.