玉米播种机高速射流导种装置设计与试验

Design and Experiment of High-speed Jet Seed Guide Device for Corn Seeder

摘要:

玉米高速播种已成为当前玉米播种的发展趋势,针对高速作业条件下,传统重力式导种装置存在明显局限性,种子与导种管之间的碰撞加剧,导致播种均匀性下降、甚至发生重播和漏播问题,本文设计一种可应用于播种机高速作业的射流导种装置。通过对种子导种全过程的运动分析,确定该装置的主要结构与参数。运用DEM – CFD耦合仿真技术,模拟种子在气流裹挟下的导种过程,并对设计参数进行优化。利用排种器性能试验台验证高速射流导种装置性能。台架试验结果表明:作业速度为12km/ h、株距为25cm、气流速度80m/s时,粒距合格率达到93.2% ,粒距变异系数不高于14.72%。与重力式导种装置相比,高速射流导种装置在高速作业条件下具有更好的播种性能,粒距合格率提高8.1个百分点,粒距变异系数降低6.48个百分点。田间试验结果表明:该高速射流导种装置可适配12.37km/h及以下中高速播种作业,能够满足玉米高速精密播种的作业要求。

Abstract:

High-speed corn seeding has become the current trend in corn planting. Under high-speed operation conditions, the traditional gravity-based seed guiding device has obvious limitations. The collision between the seeds and the seed guiding tube intensifies, resulting in decreased seeding uniformity and even re-seeding and missed seeding phenomena, which have adverse effects on crop yield. To address these challenges, a jet seed guiding device that can be applied to high-speed operation of the seeder was designed. Through kinematic analysis of the entire seed guiding process, the main structure and parameters of the device were determined. Using DEM – CFD coupled simulation technology, the seed guiding process under the influence of air flow was simulated, and the design parameters were optimized. This simulation provided a basis for optimizing the key design parameters, thereby improving the stability of seed flow and seeding uniformity. The performance of the high-speed jet seed guiding device was verified by using the seed distributor performance test bench. Compared with the traditional gravity-based seed guiding device, the high-speed jet seed guiding device showed significant improvement in seeding performance under high-speed operation conditions. The results showed that when the operating speed was 12km/h, the plant spacing was 25cm, and the air flow speed was greater than 80m/s, the qualified particle spacing reached 93.2%, and the coefficient of variation of particle spacing was no more than 14.72% . Compared with the gravity-based seed guiding device, the high-speed jet seed guiding device had better seeding performance under high-speed operation conditions, with an increase of 8.1 percentage points in the qualified particle spacing and a reduction of 6.48 percentage points in the coefficient of variation of particle spacing. This device had important practical application value in promoting the high-quality and efficient development of corn seeding operations and provides strong technical support for the advancement of high-speed precision seeding technology. Field test results showed that the high-speed jet seed guiding device was adaptable to medium-and-high-speed seeding operations at or below 12.37km/h and could satisfy the operational requirements of high-speed precision seeding for corn.