Thermoeconomic Analysis and Diagnosis of Energy Utility Systems - From Diagnosis to Prognosis

Abstract

In this paper an approach for the complete thermoeconomic diagnosis is proposed. The procedure, initially developed for the location of anomalies, is here extended in order to evaluate the expected energy savings obtained when removing each anomaly found. This is an important task when different anomalies contemporarily occur in a plant, since they can be classified according to their contribution on the reduction in the overall system efficiency. Consequently, maintenance can be more efficiently planned. Diagnosis is conduced through a thermoeconomic model of the system, built by means of available operating conditions corresponding to the plant without anomalies. The effects induced by the anomalies in the components are progressively removed. This procedure does not need to know in advance the exact location of the anomalies themselves. In this way the direct effect of the anomalies in the components where they occur is isolated, called intrinsic malfunctions. The total fuel impact associated with each malfunction is calculated by reassigning to each intrinsic malfunction their own induced effects. A simulator is used in order to determine the operating conditions corresponding to the presence of different anomalies. Then the procedure is applied in order to first locate the anomalies and then to quantify them. The results are compared with those that can be obtained by progressively eliminating the malfunctions in the simulator.