Numerical investigation of the heat transfer and fluid flow in a Carbon Monoxide boiler

We present a numerical investigation of the heat transfer and fluid flow in a Carbon Monoxide (CO) boiler. The influences of some important parameters related to the geometry of a CO boiler are also discussed, including the refractory thickness and the insertion of an ellipsoidal cone. The purpose is to improve the performance of a CO boiler, especially to alleviate hot spots, which may lead to deterioration of the refractory. It is found that the skin friction coefficient arises earlier in the DeNOx section when the refractory is thinner. Refractory thickening leads to a lower temperature in the DeNOx section. After leaving the DeNOx section, the temperature reduces due to the cooling pipes and the skin friction coefficient arises abruptly near the cooling pipes. It is also found that insertion of an ellipsoidal cone can lower the temperature in the DeNOx section and there is a larger skin friction coefficient with a larger ellipsoidal cone angle. After leaving the DeNOx section, the skin friction coefficient and the temperature both decrease. Finally, based on the result of this research and from a practical point of view, refractory thickening is a preferable choice for reducing friction, pressure drop and temperature in a CO boiler.