Optimal estimation based tube leak detection in a thermal power plant reheater

A non-intrusive method is proposed to detect tube leaks in a reheater. The method employs the non-linear state space model proposed by Jonsson et al., 1992 for heat exchangers. Extended Kalman Filter (EKF) is designed to estimate the leak sensitive parameter. The drift in the estimated parameter due to leak is detected using Cumulative Sum (CUSUM) test. Extensive simulation studies show that abnormal change in thermal resistance of reheater tubes is an indicative of leakage.