The influence of geometry characteristics of honeycomb ceramic in heat extraction zone on heat extraction rate

Abstract：The influence of geometry characteristics of honeycomb ceramic in vertical packed bed heat extraction zone on heat extraction rate was numerically studied using three-dimensional mathematical model on the basis of model validity by experimental validation.Existence of heat extraction zone honeycomb ceramic resulted into different resistance in different positions of heat extraction zone,so gas would redistribute,so one part of the gas entered space where heat exchanger was embedded and there existed directly convective heat transfer between the part of the gas and heat exchanger exterior,while the other part of the gas entered honeycomb ceramic packed in heat extraction zone,heated the honeycomb ceramic through mode of convective heat transfer and then heat was transferred to heat exchanger exterior though thermal radiation.The characteristic sizes of the packed honeycomb ceramic in heat extraction zone had influence on heat extraction zone resistance and gas redistribution,and finally influenced heat extraction rate of heat exchanger.The calculated results show heat extraction rate of heat exchanger decreases with the increasing the characteristic size in the direction of gas flow of heat extraction zone honeycomb ceramic,but when the other two characteristic sizes increase,the heat extraction rate shows a trend of first increase and then decrease.