Exergy method for the diagnosis of energy systems using measured data

The use of exergetic and thermoeconomic analysis for the diagnosis of efficiency reductions in energy systems has been widely discussed in literature. Several procedures, based on thermoeconomic analysis with the aim of locating and quantifying malfunctions, have been proposed and applied to operating plants. The correct location of anomalies is made difficult by the effects that the anomalies induce throughout the system, not only in the components where they take place. A possible approach for the correct diagnosis consists of a successive filtration of the induced effects. Diagnosis procedures are often tested on data obtained through simulators. In real applications, an additional difficulty to overcome is represented by the errors in measurements. This paper aims to analyze the effects produced by these errors on the diagnosis results, in particular whether the procedure still allows one to identify the malfunctioning components. In addition, the accuracy of results is evaluated through error bars associated with the indicators adopted for the diagnosis.