MOCOM - Model Based Condition Monitoring System for Plant Maintenance Optimisation

MOCOM, a model based condition monitoring system using process models has been developed. The system computes characteristic parameters of main process equipment. These characteristic parameters are aggregated from process control system measurements using mathematical models. Real parameters derived from input and output measurements are compared to faultless parameters derived from input measurements and a process model of the process equipment. Process parameters that describe or characterise the process condition such as effectiveness and efficiency are used. Large deviation between the faultless and real value of the characteristic parameter indicates a fault and that maintenance, work may be required. MOCOM is an on-line system which continuously updates the characteristic parameters from measurements given by the process control system. An important feature of MOCOM is the ability to trend characteristic parameters and present these for the user. The MOCOM prototype is developed in object oriented C (C++) for Windows platform. The system may be integrated in conventional maintenance systems or be used as a standalone system. The Halden Reactor has been used as a test application and further implementations are planned. Finally it is outlined how MOCOM may also be used as a part of a system for optimisation of maintenance strategy, that is to select between corrective, time based preventive or condition based maintenance. (author)