Refrigerant R134a enters an adiabatic compressor as saturated vapor at 160 kPa at a rate of 0.45m³ / min and exits at a pressure of 1 MPa and 80 ° C. Find: a) The isentropic efficiency of the compressor, b) the work per unit mass of the compressor, and c) the working power of the compressor.   Ans: a)ηC,II=52.3% b)w=73.14kJ/kg c)Ẇ=4.44kW

Energy Balance Question

4. A mass of 0.05 kg of carbon dioxide (molar mass 44 kg/kmol), occupying a volume of 0.03 m³ at 1.025 bar, is compressed reversibly until the pressure is 6.15bar. Calculate the final temperature, the work done on the CO2, and the heat supplied: i) 1.4 = constant when the process is according to a law pv ii) when the process is isothermal iii) when the process takes place in a perfectly thermally insulated cylinder. Use Cp of CO2 as 939 J/kgK, which is the cp at 400K as per tables of properties page 17.

Q3: Air undergoes a three-process cycle. if the processes are :1→ 2: constant- pressure expansion .2→ 3: constant volume 3 → 1: constant-temperature compression .The necessary information is T1 = 100°C, T2 = 600°C, and P1 = 200 kPa. R=0.287 KJ/kg.K 1) Find the net work done for 1 kg A: 32.5 KJ B: 42.5 KJ C: 52.5 KJ D: 62 KJ