Patent ID: 8775123
Filing Date: 2014-07-08
Classification: F24F,F25B

Abstract:
1. A method for the determination of a coefficient of performance of a refrigeration machine which includes a closed circuit having a refrigerant and in which an evaporator, a compressor, a condenser and an expansion valve are arranged, the method consisting of: measuring a first temperature in the region of the inlet of the compressor; measuring a second temperature in the region of the outlet of the condenser; measuring a third temperature in the region of the outlet of the expansion valve; calculating a first pressure at the outlet of the evaporator from the third measured temperature using a pressure equation of the refrigerant; calculating a second pressure at the outlet of the condenser from the second measured temperature using the pressure equation of the refrigerant; calculating a first enthalpy as a function of the second measured temperature; calculating a second enthalpy as a function of the first measured temperature and the first calculated pressure; calculating a third enthalpy as a function of a model of the compressor; calculating a heat output and a taken up electrical power of the refrigeration machine from differences of the calculated enthalpies; and determining the coefficient of performance of the refrigeration machine from a quotient of the calculated heat output and the calculated taken up electrical power.