Prediction Methods Based on Electrical Conductivity and pH Measurements in Water Coolant Chemical-Monitoring Systems

• Published in: Thermal engineering 2023-06, Vol.70 (6), p.466-471
• Main Authors: Larin, A. B., Kiet, S. V., Zotova, K. V., Ukhalova, E. G.
• Format: Article
• Language: English
• Subjects: Algorithms; Bicarbonates; Boilers; Chlorides; Conductivity meters; Coolants; Electrical resistivity; Engineering; Engineering Thermodynamics; Heat and Mass Transfer; Indicators; Mathematical analysis; New technology; Nuclear power plants; Organic acids; Phosphates; Reliability aspects; Steam electric power generation; Steam flow; Water chemistry; Water quality; Water Treatment and Water Chemistry
• ISSN: 0040-6015; 1555-6301
• DOI: 10.1134/S0040601523060071

— A shift for applying new technologies at thermal and nuclear power plants makes it possible to achieve more efficient operation of power units; in this case, however, more stringent requirements are posed to the water-coolant quality. Foreign and Russian national regulatory documents are supplemented with coolant quality indicators, in particular, the electrical conductivity of direct χ and H-cationized χ H samples of all water and steam flows and the concentrations of chlorides and organic substances in feed water and steam at χ H = 0.2–0.3 µS/cm. Continuous automatic measurements are supported under these conditions with sufficient reliability by conductivity meters and partially by pH meters, and the progress in the development of information technologies opens the possibility to implement procedures for predicting certain quality indicators based on measurement results. The article presents analytical expressions for predicting the pH value and concentrations of organic acids in condensate and feed water, phosphates and sodium in boiler water, chlorides, bicarbonates, and electrical conductivity of a degassed steam sample. The possibility of using computation algorithms for analyzing the water chemistry (WC) state is shown, and the system of equations for the ionic equilibria mathematical model that is used in the domestically produced instrument for analyzing the feed-water quality of power-generating boilers is given.