| Camellia oleifera is a unique woody oil plant in China,with a long history of planting.The vast majority of Camellia oleifera is planted in the hills and mountains south of the Yangtze River in China.The existing field fertilization device is not suitable,which results in that the fertilization of Camellia oleifera mainly depends on manpower,with low efficiency and high labor intensity.Therefore,it is of great practical significance to carry out the research on the fertilization equipment of Camellia oleifera forest.In this study,based on the study of the physical and mechanical properties of fertilizer particles and the soil of Camellia oleifera woodland,the structure design and technical parameters of the fertilizer applicator are carried out;the kinematic model of granular fertilizer is built based on the discrete element method to obtain the force law in the process of its movement;the spherical model of fertilizer particles and the geometric model of the fertilizer applicator are built,and the working parameters and structural parameters of the fertilizer applicator are carried out The simulation results are verified by experiments,and the optimal working parameters of the machine are determined finally The main research work is as follows:(1)The research work was carried out on the fertilizer particles and soil of the operation object of the fertilizer machine,and the relevant laws of the physical and mechanical properties of the operation object of the fertilizer machine were obtained,which provided the design basis and data support for the subsequent simulation and research of the fertilizer machine.The results are as follows:the average length of compound fertilizer and urea is 3.11mm and 3.04mm,the average width is 2.87mm and 2.51mm,the average thickness is 2.91mm and 2.45mm,the average equivalent diameter is 3.03mm and 2.60mm,the sphericity is 96%and 94%,The moisture content of compound fertilizer and urea is 1.28%and 0.39%respectively,and the arithmetic mean of density of compound fertilizer and urea isl.81g/cm3 and 1.12g/cm3 respectively,respectively It was found that with the increase of soil depth,the hardness of soil decreased gradually,and the maximum hardness of oil tea forest soil was 32 kg/cm2;(2)The overall structure design of the fertilizer applicator was carried out,and the working principle of the fertilizer applicator was introduced.The structure design of the transmission mechanism,the auger and the fertilizer depth adjusting device is carried out.After the structure design of the fertilizer applicator,the technical parameters of the fertilizer applicator are obtained;(3)The discrete element kinematic analysis of fertilizer particles is carried out.Through the contact judgment conditions,the velocity and angular velocity are solved by using the central difference method,and the displacement analysis model at t+At time is derived.When the fertilizer particles move to a new position,the new contact force and contact moment are generated,and the motion law of fertilizer particles in the process of fertilization is further analyzed.According to the mechanical parameters of the fertilizer particles,the spherical model of the fertilizer particles and the geometric model of the fertilizer applicator are established to determine the time step.The orthogonal experiment was designed and analyzed with the amount of fertilizer and the coefficient of variation of fertilizer particle distribution as the index,and the rotation speed of the fertilizer axis,the length of the scraper and the pitch of the auger as the factors.The simulation results show that the effect on the coefficient of variation is the rotation speed of the fertilizer axis,the length of the scraper and the pitch of the winch.When the rotation speed of fertilizer axis is 54 R/min,the length of scraper is 80 mm,and the pitch of winch is 100 mm,the effect of fertilizer application is the best.With the increase of soil depth,the soil moisture first increases,then tends to balance,the maximum moisture content is 20.5%,the minimum moisture content is 12.0%;(4)Through the second regression orthogonal test,the regression model of the distribution coefficient of variation of the rotation speed of the fertilizer axis,the length of the scraper and the pitch of the winch was established,and the analysis of the interaction response of each factor showed that the interaction between the length of the scraper and the pitch of the winch had an obvious effect on the coefficient of variation.The feasibility test of fertilizer application equipment was carried out.The results showed that the fertilizer application equipment of Camellia oleifera could run smoothly in the Camellia oleifera forest,and could adjust the depth of furrow fertilization for different terrain,and could meet the needs of normal fertilization operation of Camellia oleifera.The operation performance parameters of the fertilizer applicator are obtained.When the rotation speed of the fertilizer axis of the fertilizer applicator is 54r/min,the length of the scraper is 80mm,and the pitch of the auger is 100mm,the uniformity of fertilizer application is good,and the amount of fertilizer application is close to the theoretical value,which can be applied to the fertilizer application of the camellia oil forest. |
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