Numerical simulation of convective superheaters in steam boilers

作者：Taler Dawid; Trojan Marcin^*; Dzierwa Piotr; Kaczmarski Karol; Taler Jan

来源：International Journal of Thermal Sciences, 2018, 129: 320-333.

DOI：10.1016/j.ijthermalsci.2018.03.005

• Steam superheater
• Heat exchangers
• Mathematical model
• Ash fouling

Superheaters are high-temperature cross-flow heat exchangers. Steam flows inside the tubes, and the flue gas outside in a direction perpendicular to the axes of the tubes. However, they differ very substantially from the other heat exchangers operating at low temperatures because of the high dependence of steam heat capacity on temperature and radiation heat transfer on the flue gas side. Also, the flow tube arrangement is usually complicated. Due to the work of superheaters in a harsh environment, they are prone to damage. About 40% of the emergency shutdowns of boilers are caused by overheating of the tube material which in turn causes them to break. The paper presents the mathematical model of the superheater. The finite difference model with distributed parameters is based on the solution of energy conservation equations for steam, tube wall, and flue gas. The CFD superheater model was also developed to verify the finite-difference model. The model developed in the paper can be used to assess the fouling degree of the superheater tubes by ash.

• 出版日期2018-7