Performance Monitoring of Coal-Fired Units in Real-Time

Power plant performance monitoring can be accomplished in real-time using the data already available on the plant computer in the control room. Because of this, plant operators can be provided with quantitative real-time feedback on the impact of any operational change on plant efficiency and economics. With funding from several major U.S. Utilities and the Electric Power Research Institute (EPRI) the Center for Energy Systems Research (CESR) at Tennessee Technological University (TTU) has developed a Real-Time Performance Monitoring System for evaluating plant operations continuously. The calculations are based on the output/loss method. Coal analysis in real-time is obtained by using information on flue gas composition. This is a unique technology developed at CESR. The steady-state thermodynamic model includes on the fire-side the FD and ID fans, the air preheater, the coal pulverizers and the boiler. It includes flow rate, pressure and temperature of the feedwater, main steam, cold reheat steam and the hot reheat steam on the steam-side of the calculations. The model performs calculations and displays results every minute (or whatever averaging time is chosen) by reading relevant data from the plant computer. One of the primary advantages of this method is that it can be customized to a given unit with given instrumentation. The Real-Time Performance Model has been successfully installed in 10 coal fired units in the U.S.A., four 200 MW units in New Zealand, one 200 MW unit in India and one 900 MW unit in China. In this paper the output/loss method will be introduced. The thermodynamic model with which calculations are performed will be described in detail. Field results from several units around the world will be presented. Examples of strategies for performance enhancement based on real-time performance monitoring will be discussed.