Numerical modeling of superheaters in steam boilers / Wiesław Zima // W: Mathematical modeling and monitoring of steam boilers / ed. by Magdalena Jaremkiewicz ; Politechnika Krakowska im. Tadeusza Kościuszki. ... więcej

Numerical modeling of superheaters in steam boilers / Wiesław Zima // W: Mathematical modeling and monitoring of steam boilers / ed. by Magdalena Jaremkiewicz ; Politechnika Krakowska im. Tadeusza Kościuszki. – Kraków : Wydaw. PK, 2015. – (Monografia / Politechnika Krakowska im. Tadeusza Kościuszki. Mechanika). – S. 113-134 : rys. – Bibliogr. 15 poz., Summ., s. 208, Streszcz., s. 211, Zsfassung, s. 214-215. – Seria gł.: Monografia / Politechnika Krakowska im. Tadeusza Kościuszki, ISSN 0860-097X ; 489

The chapter presents a method for modelling the dynamics of steam superheaters. The proposed method comprises solving the equations describing the laws of mass, momentum, and energy conservation and considers ... więcej

The chapter presents a method for modelling the dynamics of steam superheaters. The proposed method comprises solving the equations describing the laws of mass, momentum, and energy conservation and considers the superheater model as one with distributed parameters. The proposed model is one-dimensional and is suitable for pendant superheaters. In this model, the boundary conditions can be time-dependent. The computations are carried out in the direction of the heated fluid flow in one tube. The time-spatial temperature history of the separating wall is determined from the equation of transient heat conduction. As the time-spatial heat transfer coefficients at the working fluids sides are computed in the on-line mode considering the actual tube pitches and cross-flow of combustion gases, the physics of the phenomena occurring in the superheaters does not change. All the thermo-physical properties of the fluids and the material of the separating walls are also computed in real time. In order to prove the accuracy and effectiveness of the proposed method, experimental verification was carried out. The analysis of the presented comparisons demonstrates fully satisfactory convergence of the results obtained using the suggested method with measured temperature history. When analysing the presented comparisons it should be considered that many parameters affect the final result of the operation of the surfaces heated convectively (e.g. ones resulting from gradual fouling of these surfaces). Not all these parameters can be fully taken into consideration in the calculation algorithm.