Determination of correlation functions of the oxide scale growth and the temperature increase

In this paper, a method for estimating the scale growth of superheater and reheater tubes of boiler and generating the constant B which is correlating the scale growth and the increased tube metal temperature, for different operational conditions is reported. This method utilizes an empirical formula correlating the scale thickness with Larson-Miller Parameter (LMP). Finite element modeling to estimate the scale thickness on the inner surface of the tube over period of time is developed. The effects of tube geometry, mass flow rate and temperature of steam, flue gas temperature and the convection coefficient on the external surface of the tube that influenced the temperature increase in the tube metal are examined. The present results provide better estimation of the oxide scale growth and temperature increase over period of time.