On the Thermoeconomic Approach to the Diagnosis of Energy System Malfunctions. Part 5 Indicators to Diagnose Malfunctions: Applications of a New Indicator for the Location of Causes

Diagnosis procedures primarily aim at locating the control volumes where anomalies occurred. This is not a simple task, since the effects of anomalies generally propagate through the whole system and affect the behavior of several components. Some components may therefore present a reduced efficiency, although they are not sources of operation anomalies, due to non-flat efficiency curves. These induced effects are a big obstacle in the use of the thermoeconomic indicators for the search of the origin of the anomalies. As discussed in a brief overview of the several thermoeconomic indicators suggested in the literature, the reason for this inability is the focus on specific exergy consumptions as independent variables of the thermoeconomic model of the energy system. Instead, the real cause of the alteration of component behavior is the modification of its characteristic curve. Based on this concept, a new indicator measuring the alteration of the characteristic curve of the component affected by the operation anomaly is discussed and applied to the combined cycle power plant of the TADEUS problem.