Three-Dimensional Simulation of Leakages in Rotary Air Preheater of Steam Power Plant

Abstract

One of the major problems of rotary air preheaters (RAPHs) is leakage which has a direct impact on its performance reduction. The purpose of this study is to examine the behavior of different types of leakage in the RAPH and its effects on the performance of overall heat transfer. A real power plant was modeled and simulated using three-dimensional numerical approach. The details found by 3D simulation would give a better understanding of the flow behavior in the RAPH which is very important in the design and maintenance stages of each RAPH. The flow pattern and temperature distribution in clearance spaces of four radial wings and axial sector plates were investigated along with the temperature distribution of the matrix. The results revealed that radial leakage in the hot end had a more negative effect on the performance of RAPH, since in this end, both thermal energy and mass flow of air are wasted together. The effects of each leakage at different clearances were compared and the changes in air and flue gas outlet temperatures due to leakage were discussed. The results were validated with experimental data.