On-line fouling monitoring model of condenser in coal-fired power plants

The fouling of water side surfaces decreases the thermal effectiveness of the condenser and it is always one of operational focuses in coal-fired power plants. This study presents a comprehensive approach to realize the on-line fouling monitoring for the condenser in thermal power plants. Based on the operational mechanism and the coupling property, an all-condition mechanism model (ACMM) of coal-fired power plants is proposed to simulate coupling operating characters of systems. The simulation results of a 600 MW/16.7 MPa/560 degrees C/560 degrees C supercritical coal-fired power plant indicate that the model is of sufficient accuracy for performance calculations under different off-design conditions. An on-line fouling model of the condenser is presented according to simulation results of ACMM and on-line monitoring parameters from SIS system. For the fouling model, a correction as a function of the non-condensable gas is implemented to improve the accuracy of the condensation heat transfer resistance in the steam side of the condenser. The results of the on-line fouling monitoring in the field reveal that the fouling of the condenser increased with time and the fouling growth rates kept relative stable. Furthermore, this study also provided an alarm for the leakage fault in the condenser according to the abnormal fouling resistance tend. (C) 2016 Elsevier Ltd. All rights reserved.