主动防堵式免耕播种机作业粉尘特性

    Dust characteristics of active anti-blocking no-tillage planters

    • 摘要: 原茬地免耕覆秸精播机在高速作业过程中,粉尘影响气吸式排种器排种性能,导致播种质量降低。该文对作业粉尘进行物性参数测定,通过理论分析建立粉尘飘移运动学模型,运用CFD-DEM耦合和二次回归正交旋转中心组合试验方法,以作业速度、风向和风速为试验因素,粉尘浓度为评价指标,探究原茬地免耕覆秸精播机作业周围5 m空间内的粉尘分布规律。结果表明:风向和风速对粉尘浓度具有极显著影响(P<0.01),作业速度具有显著影响(P<0.05),影响主次顺序为风速、风向、作业速度;最小粉尘浓度分布空间为清秸防堵种床整备装置上方对应中间播种行0.32 m3的立方体空间范围。田间验证试验结果表明,虚拟仿真与田间试验粉尘分布范围相对误差小于8.6%,仿真分析方法可行,结果可靠。研究结果可为主动防堵式免耕播种机特别是原茬地免耕覆秸精播机防尘式气吸排种系统设计提供理论参考依据。

       

      Abstract: Abstract: No-tillage and straw mulching precision planters can be widely used in the original stubble field. The kind of active anti-blocking precision no-tillage planter is adopted the lateral straw cleaning with the anti-blocking and air suction seeding. The straw cleaning and anti-blocking seed bed preparation device can be used to clean the straw from the surface side before sowing to build a clean seed bed, Then, the air suction seeding devices can be used for the seed metering, suitable for the high-speed no-tillage seeding operation. However, the dust can be generated by the operation of straw cleaning entering into the air suction seeding device. The performance of seed metering can lead to the reduction of seed quality. The same situation can also be found in the other no-till planter air-suction seeders during operation. Therefore, it can be seriously restricted in the application and the high-speed operation of no-till planters. In this study, the physical characteristics parameters of dust in operation were determined to identify the key factors on the dust distribution in the stubble fields. 2BMFJ-5 no-till and straw mulching seeder was taken as a research object. The EDEM and FLUENT software were utilized to develop the coupling interface under the DPM platform. Specifically, the turbulence model was Reliable k-ε and the number of meshes was 21.8 million using numerical simulation, according to the N-S equation. A combined test with the quadratic regression orthogonal center of rotation, and a virtual simulation test were carried out with the operating speed, wind direction, and wind speed as the test factors, while the dust concentration as the evaluation index, in order to explore the dust characteristics in 5 m space around the machine. The results show that the wind direction and wind speed presented an extremely significant effect on the dust concentration, whereas there was a significant effect of on operation speed. The primary influence was ranked in the descending order of the wind speed, wind direction, and operation speed. The interaction of various factors also posed an effect on the dust concentration. Particularly, the interaction of operating speed and wind angle shared a highly significant effect on the mean dust concentration, whereas, the interaction of operating speed and wind speed was a significant effect on the mean dust concentration. The dust was mainly distributed in on the left and right sides of the no-tillage and straw mulching planter in the original stubble field and around the seeding monomer. The secondary distribution was in the front of the machine, above the seeding monomer and above the straw cleaning, and anti-blocking seed bed preparation device. The distribution space of the minimum dust concentration was the cube space, corresponding to the middle seeding row above the straw cleaning and anti-blocking seed bed preparation device. The dust density was (41.99±10.87) mg/m3, in which 86.24%±4.14% of soil particles, 4.15%±1.55% of straw stem, and 9.61%±2.59% of straw leaf. A series of field validation tests were also carried out to verify the simulation. Under the typical natural wind direction and wind speed, the soil hardness of 23.6 kg/cm2, the water content of 20.17%, the straw coverage of 1.97 kg/m2, and the water content of 28.13%, no-tillage and straw mulching planter operation speed of 9 km/h in the original stubble field during the time of sowing in Heilongjiang Province. The results showed that the relative error of dust distribution between the virtual simulation and field test was not greater than 8.6%, indicating the a reliable simulation. This finding can also provide a theoretical reference to design the active straw cleaning and anti-blocking no-tillage planter, especially for the dust proof air suction seeding system of the no-tillage and straw mulching planter in the original stubble field. The air-absorbing seed dischargers can be expected to serve as the high-speed no-tillers.

       

    /

    返回文章
    返回