An operating zone model for safety and efficiency monitoring of power generation units in thermal power plants

Safe and efficient operations of thermal power plants become increasingly important, especially in compensating for electricity supply fluctuations in renewable energy. This paper proposes a method to build an operating zone model for safety and efficiency monitoring of power generation units in thermal power plants. The operating zone is a high-dimensional geometric space formed by all steady-state operating points in safe conditions of the coal flow rate, steam valve position, steam pressure and active power. Those operating points are obtained based on allowable variation ranges of process variables and mechanistic models describing the relationships among process variables. The main technical challenge is how to measure uncertainties of mechanistic models estimated from historical data disturbed by noticeable measurement noise. Bayesian theory and goodness-of-fit tests are exploited to tackle this challenge by yielding probability density functions of model parameters. A performance index is defined based on the operating zone model to assess the safety and efficiency of power generation units. Industrial case studies at a large-scale thermal power plant are provided to illustrate the effectiveness of the proposed method.