COP's

[jen2]

Hello again. I could also do with some clarification on COP for a refrigeration System.
Please could anyone correct me if I'm wrong!!
Chart COP is heat input/ work input. as I understand it, this basically measures the efficiency between the Compressor and the evaporator.
System COP is evaporator power / mechanical Power and gives a value for the efficiency between mechanical power put in to the system and the Power the evaporator consumes, this is why it produces a lower value than the chart COP?
Overall COP is evaporator power / electrical power and gives a n efficiency value for the amout of electricity put in to drive the motor for the compressor and the evaporator, hence it is lower than the system COP? Is this right as it confuses the hell out of me!! Cheers

 

[quark]

I don't know what you mean by chart COP and overall COP. Precisely and technically, COP is the ratio of refrigerating effect and power input.

This gives you an indication of how effectively your electric energy is converted into heat. Generally, heat is classified as low grade energy and electricity as high grade energy and the conversion of high grade to low grade is inefficient. Our target is to reduce inefficiency.

If you are speaking of a refrigerating system, the COP is the ratio of heat absorbed by the evaporator and the motor power. COP of a refrigerating machine is higher at full load and tends to decrease at low loads.

The difference between theoretical and actual COP depends upon many operating parameters viz., load, chilled water entering temperature, power factor, cooling water entering temperature etc.