Measurement of Refrigeration Capacity

[mad fridgie]

I didn't see any plant with ammonia flow meters.
Compressor problem. Discharge temperature will jump if discharge valves leak. Suction valves leak will reduce energy use. Compare current energy use at certain operating conditions with compressor engineering data from manufacturer.

You can get a flow meter for just about any material.
To calculate COP of a system you need to know your load (the bit you are cooling) In rooms this is quite difficult (practically hugh variables) By knowing the actual mass flow of the refrigerant and the conditions it is at, you can calculate refrigeration effect, if you then remove system losses either by detail measurement or theoretical calcs you will end u with nett refrigeration effect. (how detailed to determins accuracy)
Damage to compressor parts valves, rings etc, effect volumetric efficiency, which inturn effects actual mass flow, thus makes changes to power draw (COP)