摘要
现有牧草种子收获机在收获牧草种子时,其收获总损失率与破碎率较高,杂质清选效果差,沉降不充分。为了解决上述问题,在现有沉降箱的基础上进行理论及结构分析,结合具体需求及整机结构外形来改进沉降箱清选结构,设计了一种圆弧减速挡板,减小了种子受到的冲击力,调整了挡板的大小以及位置,使得更多的种子经过沉降进行清选,提升牧草种子收获的质量合格率。通过计算流体动力学仿真对沉降分离装置的内部流场进行了仿真模拟,选择雷诺应力模型和DPM模型分别对气相和固相进行模拟得到气流场分布图和颗粒场的运动轨迹图。结果表明设计的圆弧减速挡板对比折线降速挡板的结构提升了种子沉降率,并减小了种子破碎率,并且在入口风速提高时,提高了箱底种子捕获率。通过牧草种子收获机收割苜蓿实地试验,分别对比了无挡板以及折线减速挡板的收获合格率。结果表明,采用圆弧减速挡板的沉降箱收获种子时沉降损失率为0.19%,破碎率为0.9%,均达到相关行业标准,证明了该装置的有效性。
When harvesting forage seeds,the current harvester has high total loss rate and crushing rate,poor cleaning effect of impurities and insufficient settlement.In order to solve the above problems,theoretical and structural analysis on the basis of the existing settling box were carried out,the cleaning structure of the settling box in combination with specific requirements and the overall structure shape was improved,a circular arc decelerating baffle was designed,the impact force on the seeds was reduced,the size and position of the baffle were adjusted,and more seeds were made clean by settling.The qualified rate of forage seed harvest quality was improved.By means of computational fluid dynamics simulation,the internal flow field of the settlement separation unit was simulated.Reynolds stress model and DPM model were selected to simulate the gas phase and solid phase respectively to obtain the airflow field distribution diagram and the particle field motion trajectory diagram.The results showed that the circular arc deceleration baffle designed compared with the structure of the broken line deceleration baffle increased the seed settlement rate,reduced the seed crushing rate,and increased the bottom capture rate when the inlet wind speed was increased.Field experiments were carried out to harvest alfalfa by forage seed harvester,and the harvest qualification rates of baffle free and broken line reducer were compared.The results showed that the sedimentation loss rate was 0.19%and the crushing rate was 0.9%,both of which met the national standard and proved the effectiveness of the device.
作者
兰凌霄
李凤鸣
王强
刘贵林
李伟
刘伟
LAN Lingxiao;LI Fengming;WANG Qiang;LIU Guilin;LI Wei;LIU Wei(Hohhot Branch of Chinese Academy of Agricultural Mechanization Sciences Co.,Ltd.,Huhhot 010010,China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2023年第S02期150-155,172,共7页
Transactions of the Chinese Society for Agricultural Machinery
基金
内蒙古自治区科技重大专项(2020ZD0001)
关键词
牧草种子收获机
沉降箱
圆弧减速挡板
计算流体力学
forage seed harvester
settlement box
arc cancellation baffle
computational fluid dynamics
