Abstract:
Abstract: Application of chemical fertilizer is an important part in the process of crop production management. The research showed that precise application of chemical fertilizer had great significance to improving the utilization rate of fertilizer and reducing the amount of fertilizer application. The outer fluted roller fertilizer apparatus is the key carrier in the process of precise variable rate fertilization. In order to optimize the fertilizer performance of the existing outer fluted roller fertilizer apparatus comprehensively, the discrete element simulation technology, orthogonal test and 3D rapid prototyping technology were used in this paper. The straight flute wheel structural was taken as research object, and influence regularity of 4 key structural parameters such as groove wheel radius, groove numbers, effective working length and groove section on fertilizer performance was analyzed. A discrete element simulation platform was set up in this paper for outer fluted roller fertilizer apparatus, which mainly consists of fertilization bin, fertilization box, the outer groove roller, fertilization tongue, fertilization pipe, soil ground and fertilizer particles. In the simulation test, the advancing speed of outer fluted roller fertilizer apparatus was 0.5 m/s, the working height was 500 mm, and the rotation speed of outer fluted roller was 20 r/min. The coefficient of variation of the fertilizer was selected as the performance evaluation index of outer fluted roller fertilizer apparatus. The test results of the interaction of 3 factors showed that there was no interaction between groove wheel radius and groove numbers, and between effective working length and groove numbers, there was a certain interaction between groove wheel radius and number of the grooves. The L18 (37) standard orthogonal table was selected according to the result of interaction. The orthogonal result showed that factors affecting fertilizer performance, from importance to secondary, mainly include groove numbers, groove wheel radius, effective working length, interaction between groove wheel radius and groove numbers, and groove section. The groove numbers had very significant influence on fertilizer performance. The groove wheel radius had significant influence on fertilizer performance. The effective working length, interaction between groove wheel radius and groove numbers, and groove section had no significant influence on fertilizer performance. The optimum combination of parameters is that the groove numbers is 7, the radius of grooves is 30 mm, the effective working length is 20 mm, and the groove section is circular-arc, and the coefficient of variation of the uniformity of fertilizer for this type of outer fluted roller fertilizer apparatus is 1.75%. In order to test the simulation structure parameters optimization results of outer fluted roller fertilizer apparatus, a bench test was carried out under the optimal combination of structural parameters. The bench test mainly consisted of fluted roller fertilizer apparatus, power motor of conveyor belt, power motor of external groove, control box, conveyor belt and ruler. The experimental results showed that the coefficient of variation of fluted roller fertilizer apparatus is 5.48%. Considering that there may be some errors in the bench test, the results of the bench test were basically consistent with the simulation results, which proved that the discrete element method is feasible to optimize the structural parameters of fluted roller fertilizer apparatus. This research results can provide references for optimizing the structural parameters of fluted roller fertilizer apparatus and improving the performance of the fertilizer.