玉米收获机籽粒回收装置气流场分布试验研究

为了提高玉米收获机籽粒回收率和减小回收籽粒的含杂率，设计了上置风机振动筛式籽粒回收装置，用于清除轻杂物，促使苞叶翻转并顺利排出机外，并对其气流场的主要影响因素进行试验研究。为探究分风板对回收室内气流场的影响，应用Fluent模块进行仿真分析，仿真结果表明，分风板能够有效改善回收室内气流分布情况。为获取籽粒回收室内气流场的精确分布，在回收室内设置若干个测量点，采用风速仪测量各点处的风速，并观察分析苞叶在气流场作用下的姿态。为探究所设计气流场对籽粒回收率的影响，选取风机转速、出风倾角及作业速度为试验因素，籽粒回收率为评价指标，进行了3因素3水平正交田间试验，利用SPSS软件对试验结果进行方差和均值分析，得到各试验因素对试验指标的影响和主次顺序。试验结果表明，风机转速对籽粒回收率影响最大，出风倾角次之，而作业速度影响不显著。最佳组合为风机转速1 000 r/min，出风倾角15°。 

Experiment and Analysis of Airflow Field Distribution in Corn Harvester Grain Recovery Device

In order to improve corn harvester's grain recovery rate and reduce impurity content of recovered grain，an upper fan shaker-type grain recovery device was designed.Main influencing factors of airflow field were experimentally studied.In addition to removing light debris，the designed airflow field also required that bract leaves could be turned upside down and smoothly discharged out of the machine.In order to explore influence of air distribution plate on airflow field in recycling room，the Fluent module was used for simulation analysis.Simulation results showed that air distribution plate could effectively improve airflow distribution in recycling room.In order to obtain distribution of airflow field in grain recovery room，several measurement points were set in recovery room，wind speed was measured at each point with an anemometer，and posture of bract leaves discharged from peeling device under action of airflow field was observed and analyzed.Fan speed，inclination of wind and operating speed were selected as test factors，and grain recovery rate was an evaluation index.A three-factor and three-level orthogonal field test was performed.The SPSS software was used to analyze variance and mean of test results.Influence of each test factor on test index and order of primary and secondary were obtained.Test results showed that speed of fan had the greatest effect on recovery rate of grain，followed by inclination angle of wind，and effect of operating speed was not significant.The best combination was a fan speed of 1000 r/min and an outflow angle of 15 °.