A full-cycle numerical simulation of a circulating fluidized bed(CFB)by the use of the computational particle fluid dynamics(CPFD)method has been developed.The effects of the presence or absence of the secondary air,d...A full-cycle numerical simulation of a circulating fluidized bed(CFB)by the use of the computational particle fluid dynamics(CPFD)method has been developed.The effects of the presence or absence of the secondary air,different secondary air positions,and different secondary air ratios on the gas–solid flow characteristics were explored.The results show that the presence of the secondary air makes a core-annular structure of the velocity distribution of particles in the fluidized bed,which enhances the uniformity of particles’distribution and the stability of fluidization.The position and the ratio of the secondary air have a significant impact on the particle distribution,particle flow rate,and gas flow rate in the fluidized bed.When the secondary air position and ratio are optimal,the particles,particle flow rate,and air flow rate in the CFB are evenly distributed,the gas–solid flow state is good,and the CFB can operate stably.展开更多
Air DTH hammer has been successfully applied in minor-caliber solid mineral exploration,water-well drilling and other drilling areas. In order to expand the applications of the technology,the authors further studied t...Air DTH hammer has been successfully applied in minor-caliber solid mineral exploration,water-well drilling and other drilling areas. In order to expand the applications of the technology,the authors further studied the principle and analyzed the mechanism of reverse circulation drilling technique with air DTH hammer to get the perfect assembles of equipments by optimizing working parameters. No parameter seemed more important than the air volume because it could maintain the working performance stability. The minimum air volume is related to the parameters such as depth and pressure,which was calculated under the actual conditions. It was solved for the air injection flow tables of the air DTH Hammer working at the different pressures. According to the data tables,operators could adjust the air volume to meet the demand on this technique,which had a realistic guiding significance. So it could build up a set of systematic and complete hi-technique.展开更多
基金the National Key Research and Development Program of China(grant No.2022YFC2904401)Guangxi Science and Technology Major Project(grant No.GuiKe AA23023033).
文摘A full-cycle numerical simulation of a circulating fluidized bed(CFB)by the use of the computational particle fluid dynamics(CPFD)method has been developed.The effects of the presence or absence of the secondary air,different secondary air positions,and different secondary air ratios on the gas–solid flow characteristics were explored.The results show that the presence of the secondary air makes a core-annular structure of the velocity distribution of particles in the fluidized bed,which enhances the uniformity of particles’distribution and the stability of fluidization.The position and the ratio of the secondary air have a significant impact on the particle distribution,particle flow rate,and gas flow rate in the fluidized bed.When the secondary air position and ratio are optimal,the particles,particle flow rate,and air flow rate in the CFB are evenly distributed,the gas–solid flow state is good,and the CFB can operate stably.
基金supported by the project of the feasibility study on air reverse circulation drilling system,research foundation for out standingteachers,Jilin University(No.2006220100003435)
文摘Air DTH hammer has been successfully applied in minor-caliber solid mineral exploration,water-well drilling and other drilling areas. In order to expand the applications of the technology,the authors further studied the principle and analyzed the mechanism of reverse circulation drilling technique with air DTH hammer to get the perfect assembles of equipments by optimizing working parameters. No parameter seemed more important than the air volume because it could maintain the working performance stability. The minimum air volume is related to the parameters such as depth and pressure,which was calculated under the actual conditions. It was solved for the air injection flow tables of the air DTH Hammer working at the different pressures. According to the data tables,operators could adjust the air volume to meet the demand on this technique,which had a realistic guiding significance. So it could build up a set of systematic and complete hi-technique.
