Numerical study on heat transfer and thermal stress of the upper cone membrane wall in radiant syngas cooler

摘要

The high temperature syngas induced from the entrained-flow gasifier contains a large amount of sensible heat, which can be efficiently recovered by radiant syngas cooler (RSC). In this work, the membrane wall models of the upper cone section in the RSC are established. The heat transfer characteristics between membrane wall and syngas are explored by numerical simulation under different operating conditions, and the thermal stress distribution on the membrane wall surface is calculated by the fluid-structure coupling method. The results show that the inner surface of the fin is partially overheated and the maximum stress exceeds the allowable stress of the material when there is no protection for the membrane wall. The increase of inlet syngas temperature and flow rate will enhance heat transfer of the upper cone membrane wall, and the effect of the inlet syngas temperature is more obvious. After the application of the silicon carbide refractory, the surface temperature of the membrane wall, especially the temperature of the wide fin parts, is greatly reduced. Moreover, the membrane wall is slightly deformed and warped due to the temperature difference between the two sides of the membrane wall.