气送式高速玉米精量排种器导流涡轮设计与试验

Design and Experiment of Diversion Turbine of Air-assisted High Speed Maize Precision Seed Metering Device

为了提高气送式高速玉米精量排种器的工作性能,设计了3种结构类型的导流涡轮,通过计算流体力学(Computational fluid dynamic,CFD)方法模拟仿真与理论分析得出,导流涡轮可有效提高排种器内部空气的流动性,增大外圈型孔处空气流速流量,增大压覆作用力,且具有较大迎风角和具备曲线结构的导流涡轮C具有较好的扰动性和导流性,效果最佳。为了获得安装有导流涡轮C排种器的最佳性能参数,以工作速度、种子喂入量和气送风压为试验因素,以合格指数、漏播指数和重播指数为试验指标进行三元二次回归正交旋转组合试验,并应用Design-Expert 8.0.6软件对试验数据进行多元回归分析和响应曲面分析,得到了各因素对指标的影响关系。采用多目标优化方法,确定最佳参数组合为:工作速度为9.8 km/h、种子喂入量为1.8 kg/min、气送风压为8 kPa。此时,排种器合格指数最高,其性能指标为合格指数91.32%、漏播指数2.83%、重播指数5.85%。对优化结果进行对比验证试验,在相同条件下与未安装导流涡轮的排种器进行对比表明,安装导流涡轮可以有效提高排种器工作性能。

In order to make the flow field distributed orderly in the air-assisted high speed maize precision seed metering device,thereby improving the working performance of the seed metering device,three kinds of structure type diversion turbine were designed.Through the simulation and theoretical analysis of CFD method,the diversion turbine can effectively improve the air flow inside the seeding device and increase air speed where type hole in outer ring.At the air flow rate,the pressing force was increased,and the C diversion turbine with a large windward angle and a curved structure had better disturbance and guiding,and the effect was optimal.In order to obtain the best performance parameters of the C diversion turbine installed,the operation velocity,quantity of feeding and wind pressure were used as test factors,and the qualified index,the missing index and the multiple index were used as test indicators.A three-factor quadratic rotation orthogonal combination test was performed and the multiple regression analysis and response surface analysis of the test data were carried out by Design-Expert 8.0.6 software,and the influence of various factors on the indicators was obtained.The multi-objective optimization method was used to determine the optimal combination of parameters:the operation velocity was 9.8 km/h,the quantity of feeding was 1.8 kg/min,and wind pressure was 8 kPa and the qualified index of seed metering was the highest.At this time,the qualified index was 91.32%,the missing index was 2.83%,and the multiple index was 5.85%.The comparison verification test was carried out on the optimization results,and the comparison was made under the same conditions with the uninstalled diversion turbine seed metering device,and it was found that the installation of the diversion turbine can effectively improve the working performance of the seed metering device.