Answer:
COP=10.65
a)Evaporator pressure=337.7 KPa
Condenser pressure=770.2KPa
b)Evaporator pressure=566.1 KPa
Condenser pressure=1192 KPa
c)Evaporator pressure= 0.81 KPa
Condenser pressure=4.024 KPa
d)Evaporator pressure= 394.84KPa
Condenser pressure=1167.2KPa
Explanation:
Given that cycle is working under Carnot cycle and we know that Carnot cycle is the ideal cycle for vapor compression.We also know that COP of Carnot cycle does not depends on the working fluids it depends only at the temperature limits.that is why COP of all fluids will be same.
COP of Carnot cycle given as follows
Here given that
COP=10.65
Now to find the condenser and evaporator pressure
We know that inside the wet region only one property needed to find other properties.Here given that temperature at condenser and at evaporator so the condenser and evaporator pressure will be the saturation pressure condenser and evaporator at given temperature for all fluids.
a)For refrigerant 134a
From properties table of refrigerant 134a
Evaporator pressure=337.7 KPa (pressure corresponding to 4°C)
Condenser pressure=770.2KPa (pressure corresponding to 30°C)
b)For refrigerant R22
From properties table of refrigerant R22
Evaporator pressure=566.1 KPa (pressure corresponding to 4°C)
Condenser pressure=1192 KPa (pressure corresponding to 30°C)
c)For refrigerant water
From properties table of refrigerant water
Evaporator pressure= 0.81 KPa (pressure corresponding to 4°C)
Condenser pressure=4.024 KPa (pressure corresponding to 30°C)
d)For refrigerant ammonia
From properties table of refrigerant ammonia
Evaporator pressure= 394.84KPa (pressure corresponding to 4°C)
Condenser pressure=1167.2KPa (pressure corresponding to 30°C)