Simulation Modelling of Cycle Chemistry Monitoring of Water and Steam Quality at Thermal Power Plants

Abstract

Cycle chemistry monitoring systems are intended for online comprehensive automatic monitoring, analysis, diagnostics, and prediction of the water chemistry in power equipment in all regimes of its operation, including startups and shutdowns, as well as for remote automatic control of one or several processes in the serviced process facility. Basic requirements for cycle chemistry monitoring systems are formulated. Mathematical models, which are based on the material balance, ionic composition of the coolant, and recurrent neural networks, have been developed and studied. They enable us to predict the concentration of impurities along the power unit’s path to prevent failures of the water chemistry. An algorithm has been developed for online quality assessment, based on dimensionless coefficients that provide fair information on the water-chemistry conditions and help to detect failures affecting the water chemistry. A simulation model with a user interface has been developed based on a set of algorithms considering the requirements for cycle chemistry monitoring systems, such as visualization, interactivity, reporting, customization, scalability, continuity, and simplicity. The model facilitates the activities performed by the operational personnel of power plants as to decision-making and prevention of failures of the water chemistry of the power unit, enables us to monitor the process parameters of the power unit in real time, analyze statistical data, predict parameters using algorithms on the basis of the material balance, ionic equilibriums, and neural networks. A user manual has been prepared to help one to understand the program interface. The manual contains a brief description of the system structure, including information and diagnostic functions, basic elements of the mnemonic diagram, and a set of control buttons.