基于EDEM软件的肥料调配装置关键部件参数优化与试验

为实现播种作业条件下肥料调比的分层深施,以满足不同作物整个生育期的养分供应,设计了肥料调配装置,并通过理论分析的方法确定了各关键部件的主要参数。以挡杆直径及分肥份数为试验因素,合格系数及波动系数为试验指标,分别采用仿真试验及验证试验的方法,进行二因素三水平正交肥料均布器参数优化试验研究,试验结果表明:均肥份数为极显著影响(P0.01),挡杆直径为显著影响(P0.05);肥料均布器最优参数为挡杆直径4 mm,均肥份数16,此时,试验指标合格系数及波动系数的仿真值及试验值分别为0.903、0.928及68.6、78,相对误差分别为2.19%、12.05%,验证试验与仿真试验具有相同的因素指标响应趋势,利用仿真试验进行肥料均布器参数优化具有可行性。该研究为肥料调配装置的设计研究提供了参考。

Parameter optimization and test of key parts of fertilizer allocation device based on EDEM software

Abstract: Because of the covering of a large amount of root and straw after no-tillage sowing, when doing inter-tillage and topdressing, it will cause the rate of seedling injury to increase and affect crop yield, and meanwhile, due to no fertilizer application before no-tillage sowing, so it is very important to supply sufficient fertilizer to meet different crops' nutrient requirements on the growth duration. Relevant research points out that, when the layer spacing and ratio between based fertilizer and seed fertilizer are 6 cm and 3:7 for wheat, the fertilizer can guarantee crop's nutrient requirements in different stages, but for soybean, it is 4-8 cm and 1:2, and other crops are also different. There are many research reports about layered fertilization ditcher in and abroad, but there are few researches on fertilizer allocation device. So, it is very important to design a new fertilizer allocation device with adjustable ratio. The application of prototype simulation technology of granular materials has become simple and easy with the increase of computer operation speed and the introduction of EDEM, and meanwhile, it can shorten the time of research and development cycle and reduce the costs. A new fertilizer allocation device with adjustable ratio, which consists of bevelled tongue outer groove-wheel fertilizer feeder, fertilizer uniform distribution device and fertilizer ratio-adjusting device, has been designed, and it has the function of separating the fertilizer in different layers in adjustable setting proportion, and meanwhile, the main parameters of key parts have been made by theory analysis. In order to enhance the accuracy and stability of fertilizer allocation device with adjustable ratio and analyze the influence on working performance when structure parameters of fertilizer uniform allocation device change, at first, the discrete element simulation model of fertilizer allocation device with adjustable ratio is built by using EDEM and the working process is simulated. The fertilizer particles' space distribution in entrance and exit of fertilizer uniform distribution device indicates the device can enhance the uniformity of particles' space distribution and realize its function. The bar diameter and the divided number are selected as test factors, the qualified index and the wave index were selected as index, and the two-factor and three-level orthogonal parameter optimization test is conducted. The results indicate that, for the 2 test indices, the divided number is very significant (P<0.01) and the bar diameter is significant (P<0.05); the qualified index decreases with the divided number and the bar diameter increasing, and the wave index decreases with the divided number increasing and the bar diameter decreasing; the qualified index is 0.903, the wave index is 68.6, and the fertilizer uniformity distribution device has the best working performance when the bar diameter is 4 mm and the divided number is 16. Second, in order to verify the simulation test results and prove the feasibility of parameter optimization of fertilizer uniform distribution device using simulation test method, different fertilizer uniform distribution devices have been built and the verification test has been carried out with the same test method. The verification test has the same results with the simulation, but in the verification test, the qualified index is 0.928 and the wave index is 78.0 when the optimized structure parameters are also 4 mm bar diameter and divided number of 16. The simulation test and verification test have the same response of factors, and the simulation parameter optimization has been validated which show the simulation test method is feasible. The result has a certain reference value for the research of fertilizer allocation device.