Numerical study on dynamic ash deposition and heat transfer characteristics of radiant syngas cooler

Abstract

Ash deposition greatly influences the performance of Radiant Syngas Cooler (RSC) which plays a pivotal role in the heat recovering process in coal gasification technology. Therefore, a numerical model of ash deposition coupled with heat transfer is established in present study to predict the ash deposition of RSC, and the effects of inlet temperature and division wall structure on deposition characteristics are further discussed. The simulation results indicate that the particle impact mainly occurs in the transition region of the jet flow to plug flow, while the particle deposit mainly occurs in the recirculation region. The deposition of inner wall and division wall shows a malignant growth pattern successively with the width increase of division wall. The division wall of 400 mm width is more conducive to the safe and stable operation of the RSC than those of 250 mm and 650 mm. The deposition becomes heavy with the increase of inlet temperature, and the deposition of division wall belongs to the slow growth, the large-scale detaching and the malignant growth pattern at the inlet temperature of 1573 K, 1673 K and 1773 K, respectively. Present result may provide a reference for the structural design and operational adjustment of RSC.