The ash deposition and structure characteristics for radiant syngas cooler based on the fluid-thermal-structure method using numerical simulation

Abstract

The radiant syngas cooler (RSC) has the potential to significantly enhance energy efficiency as a critical heat recovery device in entrained-flow coal gasification technology. The dimensions of the RSC have a direct impact on the flow and heat transfer processes. In this study, an analysis was conducted to evaluate the heat transfer, ash deposition, and thermal structural deformation characteristics based on the fluid-thermal-structure interaction method of the RSC. The simulation results exhibit a high degree of correlation with the industrial data. The results indicate that the increase in length-diameter ratios decreases the area of the recirculation zone. Ash deposition thickness increases with the increase of length–diameter ratios. A maximum ash deposition thickness of 15.2 mm while the length-diameter ratio is 9. The effect of ash deposition is amplified with an increase in length–diameter ratios on heat transfer. The thermal deformation of top and bottom structures is observed to increase with an increase in length–diameter ratios without ash deposition while decreasing with ash deposition. For the optimized RSC structure, an increase in inlet temperature and load results in a corresponding increase in ash layer thickness, while the effect on thermal deformation is limited. The current results can serve as a reference for the integral structural optimal design of industrial RSC.