Boiler Corrosion in Thermal Power Plant: Kinetics and Mathematical Studies

Abstract

The corrosion rate of boiler tubes is evaluated in terms of corrosive ion concentrations and temperature at a speed of rotation of 1500 rpm and a pressure of 27 bar. The mass loss method is used in the experimental work. The corrosion rate was seen to increase with both the concentration of corrosive species (Cl and Cu ions) and temperature. Values of activation energy were relatively high (14.07 kJ/mol) as the corrosive species concentration was low (0.5 ppm Cl⁻ and 0.005 ppm Cu⁺⁺). This value was reduced to 5.25 kJ/mol at a higher level of corrosive species concentration (100 ppm Cl⁻ and 0.02 ppm Cu⁺⁺). The suggested kinetic model showed an approximately zero-order reaction with respect to chloride and copper ion concentrations. Depending on mathematical principles, two models were suggested: the linear and polynomial models. Descriptive statistics outcomes showed that the polynomial model predicted data of the corrosion rate with a significant correlation coefficient (R² = 0.9983). The novelty of the present work lies in the integration of statistical modeling techniques to estimate the corrosion behavior of waterside boiler tubes as a function of water chemistry.