A refrigeration machine is required to produce ice at 0°C from water at 20°C. The machine has a condenser temperature of 298K while the evaporator temperature is 268K. The relative efficiency of the machine is 50% and 6 kg of Freon -12 refrigerants is circulated through the system per minute. The refrigerant enters the compressor with a dryness fraction of 0.6. Specific heat of water is 4.187 kJ/kg K and the latent heat of ice is 335 kJ/kg. Calculate the amount of ice produced in 24 hours. The table of properties of Freon-12 is given below
|
Temperature
K
|
Liquid heat
kJ/kg
|
Latent heat
kJ/kg
|
Entropy of liquid
kJ/kg K
|
|
298
|
59.7
|
138.0
|
0.2232
|
|
268
|
31.4
|
154.0
|
0.1251
|