圆锥形风机清选室气流场数值模拟与试验  

Numerical Simulation and Experiment of Airflow Field of Cleaning Room under Action of Conical Fan

作　　者：周璇[1,2] 王志明[1,2] 陈霓[1,2] 陈德俊[2] ZHOU Xuan;WANG Zhiming;CHEN Ni;CHEN Dejun(Department of Mechanical and Electrical Engineering,Jinhua Polytechnic,Jinhua 321017,China;Zhejiang Engineering Laboratory of Agricultural Machinery Technology and Equipment,Jinhua Polytechnic,Jinhua 321017,China)

机构地区：[1]金华职业技术学院机电工程学院,金华321017 [2]金华职业技术学院农机技术与装备浙江省工程实验室,金华321017

出　　处：《农业机械学报》2019年第3期91-100,共10页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金项目(51305182);浙江省科技厅公益技术应用研究项目(2017C32097);浙江省教育厅科研项目(Y201534330)

摘　　要：针对横置轴流联合收获机圆柱形风机产生的气流场不能解决脱出混合物在振动筛筛面堆集的问题,设计了圆锥形风机,阐述了圆锥形风机利用横向风优化脱出物筛面分布来改善清选质量的工作原理。根据清选室实际结构和尺寸建立了三维模型,利用CFDesign软件对无物料状态下圆柱形风机与不同锥度圆锥形风机作用下清选室气流场进行了数值模拟。利用布点法对不同类型风机作用下清选室气流场风速进行了测量,并通过物料分布对比试验和田间试验,验证了圆锥形风机的工作性能。结果表明:圆锥形风机作用下,清选室内产生明显的沿振动筛筛宽方向指向排草口一侧的横向风,当圆锥形风机锥度为3. 5°时,清选室气流场风速分布情况较为理想,在振动筛入口一角(下落物料最多的部位)产生的横向风速达到2. 68 m/s;与圆柱形风机相比,圆锥形风机作用下脱出物堆集中心点部位物料质量减少27. 66%,主下落区脱出物质量占脱出物总质量的比值降低10. 53个百分点,可使脱出混合物在筛分前得到预均布处理。圆锥形风机作用下,联合收获机损失率、含杂率和破碎率明显优于行业标准规定值,且与圆柱形风机相比,含杂率指标得到显著改善。In order to solve the unmatched problem between airflow field generated by traditional cylindrical fan of vibrating screening transverse axial flow combined harvester and the distribution of separated mixture on the screen surface,a conical centrifugal cleaning fan was designed and its working principle was described,which can improve the quality of cleaning by optimization of cross wind.According to the actual structure,a three-dimensional model of the cleaning device was established and a numerical simulation of the flow field distribution of cleaning room under the action of cylindrical cleaning fan and conical cleaning fan with different taper blades was conducted by using the CFDesign software.The results showed that the transverse wind was obviously produced by the conical cleaning fan along with the direction of screen width.The speed of transverse wind was increased with the increase of taper value of the fan blade,but the speed of longitudinal wind along the length of the vibrating screen was decreased with the taper value of the fan blade.The area of low wind speed zone at middle position of the vibrating screen also became larger,which was detrimental to the cleaning of mixture.The best velocity distribution of the cleaning room was appeared when the taper value of the fan blade was 3.5°.The experiment of the flow field under different types of cleaning fans was conducted by using the distributingpoint method.The results showed that the speed of transverse wind at the corner of the entrance of the vibrating screen can reach 2.68 m/s,and the speed of transverse wind at middle position of vibrating screen can reach 2.07 m/s,which was obviously bigger than the value produced by the cylindrical cleaning fan and beneficial to the distribution of the separated mixture along with the screen width.At the end of the screen length,the speed of the longitudinal wind produced by the conical cleaning fan was0.78 m/s,which was smaller than the longitudinal speed and helped to reduce the loss of grain cleaning.The d

关 键 词：横置轴流联合收获机 清选装置 圆锥形风机 气流场 数值模拟 试验 

分 类 号：S225.31[农业科学—农业机械化工程]