Maintenance and Expert Systems

This paper presents an expert system for maintenance of one stage compression refrigerating systems. First a steady state model was developed to estimate significant parameters useful for the diagnosis of the functioning state of the plant. The inputs of the model are data coming from sensors installed on the plant. In our study we concluded the necessity of redunduncies to treat efficiently senor errors. Simulating more and more faults on an experimental plant is helpful to analyze their evolution better. a,b,c 't TJV N pi Qvo mr TjiS h u Ac Tk Tm 1\.Tair; Q c manufacturer data pressure ratio volumetric efficiency compressor speed (rev Is) No•nenclature suction refrigerant density (kg/m3) manufacturer data (m3) refrigerant mass flow rate (kg/s) isentropic efficiency enthalpy (kJ /kg) external area (m2) heat transfer! coefficient(W /K.m2) condensing temperature (K) average air temperature (K) air temperature difference (K) volumetric air flow rate (m3/s) specific heat (kJ /kg)