11.) A piston and cylinder machine contains a fluid system which passes through a complete cycle of four processes. During a cycle, the sum of all heat transfers is -170 kJ. The system completes 100 cycles per minute. Complete the following table showing the method for each item and compute the net rate of work output in kW.
16.) Air flows steadily at the rate of 0.5 kg/s through an air compressor, entering at 7 m/s velocity, 100 kPa pressure, and 0.95 m3/kg volume, and leaving at 5 m/s, 700 kPa, and 0.19 m3/kg. The internal energy of the air leaving is 90 kJ/kg greater than that of the air entering. Cooling water in the compressor absorbs heat from the air at the rate of 58 kW.
a) Compute the rate of shaft work input to the air in kW.
b) Find the ratio of the inlet pipe diameter to the outlet pipe diameter.
20.) A stream of refrigerant 134a at 1 MPa and 12Β°C is mixed with another stream at 1 MPa and 60Β°C. If the mass flow rate of the cold stream is twice that of the hot one,
a) determine the temperature and the quality of the exit stream.
Points go to the clearest answers, please show as much work and steps as you can.
Process a-b b-c c-d d-a
Q (kJ/min) 0 21,000 -2,100
W (kJ/min) 2,170 0
ΞE (kJ/min) -36,600