摘要
采用离散元法EDEM对喂料器的工作过程进行了数值模拟,定量研究了喂料过程中喂料量的变化规律以及由于物料受螺旋叶片终止断面的影响,产生不稳定、不均匀的'脉动'喂料现象,此现象在转速较低的情况下尤其明显。以主轴直径X1、螺距X2和喂料转速X3为因素,以喂料质量流率Y1、稳定性Y2和出料口落料速度Y3为评价指标,按照3因素5水平正交旋转组合设计试验方法,利用Design-Expert 8.0.6软件回归分析法和响应面分析法,建立了3个因素下喂料评价指标的数学模型。通过与研制的喂料器的实际运送情况进行对比,验证了模型的可靠性。结果表明,3个因素相对喂料质量流率和流率稳定性都具有显著相关性,显著水平分别为P<0.01和P<0.05,而这3个因素与出料口落料速度无明显相关性;采用响应面法对最佳参数组寻优,得到喂料器的最佳参数组合:轴径为35 mm、螺距为57 mm、转速为139(°)/s,喂料器喂料量波动性减小、喂料稳定性得到提高。采用该参数组的虚拟试验结果显示,喂料器质量流率为13.89 g/s,稳定性为8.46 g/s。实体样机验证试验表明:采用该参数组设计的喂料器可以使得小型环模制粒机的喂料质量流率提高4.28%,喂料变异系数降低16.11%。
The discrete element analysis software EDEM was used to numerically simulate the working process. The change regulation of feeding mass and the instability and uneven ＂pulse＂phenomenon of materials caused by the end section of helical blade were quantitatively studied. The spindle diameter X1,pitch of screw X2,and feeding rate X3 were selected as the influencing factors,and the feeding mass flow rate Y1,stability Y2,drop speed of the materials Y3 were selected as evaluating indicators, and experiments were conducted by the simulation model under quadratic orthogonal rotation design. Based on the software regression analysis of Design-Expert 8. 0. 6 and response surface analysis method,the relationships between the three influencing factors and feeding evaluating indicators were established. The reliability of the simulation model was verified by comparing the performance of virtual scraper with the feeder for small-scale pellet mill. The results showed that X1,X2 and X3were significantly correlated with Y1 and Y2（ P〈0.01 and P〈0.05,respectively）,but no correlation was found with Y3. By using response surface method,the optimal aggregative index could be obtained under the condition that the spindle diameter X1 was 35 mm,the pitch of screw X2 was 57 mm and the rotation rate X3 was 139（ °） / s.Under this condition,the volatility of feeding mass was reduced and the stability was improved. The virtual test designed by the optimized parameters showed that the feeding mass flow rate was 13. 89 g / s,and the stability of mass flow rate was 8. 46 g / s. The verifying test of the physical prototype indicated that the mass flow rate was increased by 4. 28% and the coefficient of variation was reduced by 16. 11%.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2016年第2期51-58,共8页
Transactions of the Chinese Society for Agricultural Machinery
基金
公益性行业(农业)科研专项项目(201203015)
'十二五'国家科技支撑计划项目(2011BAD26B0401)
关键词
小型制粒机
喂料器
仿真优化
试验
EDEM
响应面法
small-scale pellet mill
feeder
simulation and optimization
experiment
EDEM
response surface method
