An observer-based fault detection concept for a high-pressure preheater

The authors discuss the application of a unified robust fault detection approach to a high-pressure preheater. They describe the design procedures for two approaches in the time domain, both aiming at perfect decoupling between unknown inputs and faults. If these concepts cannot be applied because certain prerequisites are not fulfilled, a modification yields an optimal compromise. Thus, an optimal solution can be achieved in the sense that a certain performance index is minimized. In order to accommodate the nonlinear application example, the fault detection approach presented is also nonlinear. The results of a simulation study of the application to a high-pressure preheater are presented