| In recent years,Xinjiang has relied on its resource advantages to vigorously develop its special industries and adjust its industrial structure,and the grape industry has developed rapidly and healthily,becoming one of the world’s three largest grape "paradise growing areas" along with Bordeaux,France and California,USA.In the process of grape cultivation,the amount and type of fertilizer applied have certain influence on the yield and quality of grapes.The reasonable application of stable fertilizer and granular fertilizer can effectively improve the yield of grapes and improve the soil structure,enhance soil activity,improve soil fertility,and have a positive effect on the sustainable use of land.However,the manual fertilization process is labor-intensive,inefficient,and ineffective in mixing stable fertilizer with granular fertilizer.Therefore,this thesis combines the requirements of grape fertilization operation,based on the determination of the material characteristics of stable fertilizer and granular fertilizer,and adopts the research idea of theoretical analysis,simulation and experimental verification of the mixing and discharging process of stable fertilizer and granular fertilizer to carry out research on the mixing and discharging device of stable fertilizer and granular fertilizer in Xinjiang vineyard.The main research contents are as follows.(1)Determination of material properties of stable fertilizer and granular fertilizer.The parameters of density,rest angle,water content,collision recovery coefficient,elastic modulus and friction coefficient of the fertilizers were determined by physical tests,in which the density of stable fertilizer was 1.4310g/cm3 and that of urea was 1.2672g/cm3;the rest angle of stable fertilizer was 42.63° and that of urea was 31.40°;the water content of stable fertilizer was 17.51%and that of urea was 0.073%.Collision recovery coefficient:0.4529 for urea-45 steel,0.1566 for urea-stable fertilizer,0.3831 for urea-urea;static friction coefficient:0.25 for urea-45 steel,0.7900 for urea-stable fertilizer,0.32 for urea-urea;0.5300 for stable fertilizer-45 steel,0.65 for stable fertilizer-stable fertilizer.(2)The overall scheme of the mixed fertilizer discharge device of stable fertilizer and granular fertilizer is determined and the mixed fertilizer discharge process is analyzed.Combined with the user’s needs and the functional requirements of the device,the overall structure of the vineyard stall fertilizer and granular fertilizer mixing and discharging device was designed,the working principle of the device was elaborated,the force situation of the granular fertilizer in the outer groove wheel discharger and the stall fertilizer in the scraper feeding part was analyzed,the transport and mixing of the stall fertilizer and granular fertilizer in the spiral churn was studied,the speed of the outer groove wheel discharging shaft,the speed of the spiral churn,the speed of the scraper shaft The influence of the parameters such as the speed of the outer groove wheel discharge shaft,the speed of the spiral churn,the speed of the scraper shaft,the horizontal distance between the granular fertilizer discharge port and the churn discharge port on the mixing performance of the device was obtained.(3)Design of key components of the fertilizer mixing and discharging device and simulation analysis of the fertilizer discharging process.The design of key components of the mixed fertilizer discharge device,such as the outer groove wheel fertilizer discharge component,the scraper fertilizer discharge component and the spiral churn fertilizer discharge component,was completed,and the structural and operating parameters of the mixed fertilizer discharge device were determined,and the fertilizer discharge process of the mixed fertilizer discharge device was simulated and analyzed with the discrete element method.The optimum combination of the four influencing factors was determined as follows:scraper shaft speed of 20.00r/min,stirrer shaft speed of 184.00r/min,outer groove wheel discharge shaft speed of 52.00r/min,and the horizontal distance between granular fertilizer discharge port and stirrer discharge port of 816.00mm.The uniformity of fertilizer mixing reaches 92.99%.(4)Trial production and test of mixed fertilizer discharge device.The average fertilizer mixing uniformity of the mixed fertilizer and granular fertilizer discharge device was 95.32%,with an average error of 2.50%compared with the optimal value of the numerical simulation,which was in line with the design requirements.The test results showed that the coefficient of variation of fertilizer application uniformity was 8.64%,the coefficient of variation of fertilizer discharge stability was 5.48%,and the breakage rate was 0.The test results of each index conformed to the national standard and could provide reference for the research of fertilizer application technology in Xinjiang vineyard. |
