Simulation And Parameter Optimization Of The Working Process Of The Outer Grooved Wheel Fertilizer Distributor Based On Discrete Element Method

The outer grooved wheel fertilizer distributor has the advantages of stable fertilizer discharging,strong adaptability.The outer grooved wheel fertilizer distributor is one of the most widely used fertilizer distributor in the fertilizer machinery at present.It is difficult to accurately control the fertilizer quantity of the outer grooved wheel fertilizer distributor.And its working parameters have an important influence on the amount of fertilizer,It is clear that the relationship between the amount of fertilizer and the working parameters is the key to improve the accuracy of fertilizer application.In the process of fertilizer discharging,there is a phenomenon of intermittent fertilizer discharging in the fertilizer distributor,lead to uneven distribution of fertilizer.How to reduce the phenomenon of fertilizer discharge is the key to improve the uniformity of fertilizer distribution.The working length of the outer grooved wheel,the speed of the fertilizer discharging shaft,and the opening angle of the fertilizer discharging tongue are the test factors,the fertilizing amount and the coefficient of variation of discharge pulsation is the test index.Using discrete element method and two regression orthogonal rotation response surface test,the influence of key working parameters on the discharge rate of fertilizer was studied,optimizing the combination of key working parameters.The main contents of this paper are as follows:(1)Measurement of Physical and Mechanical Parameters of Fertilizer Granules.Including fertilizer particle density,three axis size,elastic modulus,friction coefficient,coefficient of restitution,and the measurement results of the data analysis.(2)Three dimensional model and discrete element filling model of three kinds of fertilizer particles were established.Three dimensional model of outer groove wheel fertilizer device,The filling model of fertilizer particles is introduced into the discrete element software to set up the relevant simulation variables.And the discrete element model of the process of nitrogen fertilizer and fertilizer discharging is set up.(3)Using discrete element method and two regression orthogonal rotation response surface test.Influence of the key working parameters of the outer wheel fertilizer distributoron the fertilizer output was studied.Mathematical model of the relationship between the key working parameters and the amount of fertilizer discharge was established,based on the experimental results,contribution rate of each factor to the test index is obtained.Mean errors of the three groups of simulation and verification tests are 10.04%,12.73%,9.96%.(4)Influence of the key working parameters of the external grooved wheel type fertilizer distributor on the process of fertilizer discharging pulse was studied.The results showed that: the mathematical model of the key working parameters and the variation coefficient of the pulsation of the external grooved wheel fertilizer distributor is established.The most influential factor to the variation coefficient is opening angle followed by rotation rate and working length.Optimum working parameters of the optimized external groove wheel fertilizer distributor are as follows:working length is 45 mm,rotation rate is55r/min and opening angle is 22.5 °,simulation value and the test value of the variation coefficient of the fertilizer discharge pulsation coefficient are 10.89% and 9.55%,simulation test and the verification test have the same response trend.