竖冷设备中烧结矿石偏析行为的GPU高性能模拟

随着钢铁工业流程和技术的不断优化及节能减排要求的不断升级,如何高效回收利用各生产工序中的工业余热成为钢铁工业面临的重要课题.竖冷设备既可以有效回收烧结矿石的显热,大幅提高能源的利用率,又可以有效减少烧结工序中的粉尘,降低烧结工艺的环境污染,因此得到了高度重视.但现有竖冷设备容易出现烧结矿石的偏析问题,严重影响了显热回收的效率和设备运行的稳定性.为此,采用离散元法(discrete elementmethod,DEM)研究竖冷设备中烧结矿石的偏析,重点针对不同结构进料管对烧结矿石偏析的影响.研究发现,虽然缓冲仓内每次加入的烧结矿石皆混合均匀,但由于不同粒径的烧结矿石在进料过程中存在动量差异,导致了竖冷设备内明显的颗粒偏析,在料堆堆尖处呈现小颗粒多大颗粒少的现象,并且料层主体的偏析与进料管的结构密切相关.由于进料管的结构是进料过程的决定性因素,因此提出了通过改变进料管的结构抑制竖冷设备内烧结矿石偏析的可能途径,对提高烧结矿石的显热回收效率具有参考意义. 

SEGREGATION BEHAVIOR OF SINTER IN VERTICALLY ARRANGED COOLER WITH HIGE PERFORMANCE GPU SIMULATION

Energy-saving and emission-reduction technologies are increasingly required in the iron and steel industry, leading to urgent demanding for very efficient methods of the waste heat recovery and dust emission reduction. The vertically arranged sinter cooler is a new and an efficient apparatus to recover the sensible heat and reduce the dust pollution in the sintering process, which attracts much more attention in recent years. However, the segregation phenomenon is very severe in current design due to the wide diameter distribution of the sinter particles, leading to great reduction of the heat recovery. In order to solve this problem, the structure of the vertically arranged sinter cooler and the operating conditions should be optimized. However, it is very hard to obtain the detailed information of the distribution of the sinter particles in an industrial-scale apparatus. Along with the development in the computer science, the discrete element method (DEM) could provide more and more power for the study of particulate systems, which obtains detailed information of the particles. Thus, DEM is adopted to study the segregation of sinter particles in the vertically arranged sinter cooler. To alleviate the problem of huge computing load, the graphics processing unit (GPU) is adopted to accelerate the DEM simulation. It is found that the inlet tube has significant influence on the distribution of the sinter particles, so that three types of feeding tube structures are designed and tested. Although the sinter particles of different diameters are evenly mixed originally, severe particle segregation occurs in the sinter cooler, where the small and large sinter particles are mostly located at the center and in the periphery regions, respectively. It is obvious that the level of segregation changes with the structure of the feeding tube, which shows that both the number and inclined angle of the feeding tubes will affect the final segregation. The results show that four inlet tubes with small inclined angles are better for tailoring the size distribution of the sinters. So optimization of the structure of the inlet tubes could reduce the segregation of the sinter particles and the efficiency of sensible heat recovery will be improved accordingly.