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In response to challenge of adaptability of support and working resistance in large-height working face,the “cantilever beam-sandwich-voussoir beam” structure model is established,and the preliminary scheme of support resistance is calculated,which is verified by both numerical simulation and large-scale physical modeling.The study shows that the working resistance should meet the supporting demands of roof and rib,and keep itself with good position.The working resistance consists of two parts:one part is to bear the weight of cantilever beam due to breakage of key strata in caving zone；and the other is to balance the voussoir beam structure located in lower strata of fissure zone.When the working resistance is lower than 10 000 kN,the support operates at full capacity,and the deformation of surrounding rock increases distinctly；when the rated resistance higher than 11 000 kN,the indicator decreases distinctly.And the reasonable working resistance is determined to be 12 000 kN,which is verified feasible by the production practice.In mining practice,the terminal resistance is 8 340-10 247 kN and the percentage of safety valve opening is below 5%,so the scheme can meet the production requirements. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]