| Rape has been an important crop in China since ancient times and is one of the main sources of oil and energy.At present.China’s rape output and planting area are steadily ranking first in the world.In order to ensure the output of rapeseed,nutrient and other nutrient inputs have gradually increased in recent years.At present,China’s fertilizer production and usage ranks first in the world,and there are widespread over-fertilization and blind fertilization.The continuous development of deep side fertilization technology has changed the traditional fertilizer application mode of artificial fertilizer.Applying fertilizer near the root of the crop and covering it with soil is beneficial to the absorption of fertilizer nutrients near the root when the crop is growing.It also plays a great role in improving the utilization rate of fertilizers,and the amount of fertilization is relatively reduced compared with traditional fertilization methods.In recent years,the high-efficiency transmission effect and excellent distribution effect of the pneumatic distribution system have gradually become prominent,and its application in the field of fertilization has broad prospects.Under the premise of systematically analyzing the domestic and foreign pneumatic distribution technology and the current status of deep-side fertilization research,this topic is completed in accordance with the design concept of "one machine,multiple rows" for the problems of low fertilization quality and poor consistency of displacement in each row The design of the overall pneumatic distribution fertilizer discharge system was selected,and at the same time,an acute-angle deep fertilizer shovel was selected and designed to cooperate with the pneumatic distribution system to complete the side-deep fertilizer application.The rape seeding machine independently developed by the supporting research group is applied to improve the quality and efficiency of rape fertilization.Taking urea as the research object,according to the structural parameters of the rapeseed planter developed by the research group,the number of fertilization rows is the same as that of the sowing row,which is 6 rows.The whole pneumatic distribution system is composed of four parts:jet feeder,elbow,distributor and delivery pipeline.Use EDEM-FLUENT coupling and gas phase simulation to analyze and analyze the main working process.Using 3D printing technology to process the key components of the pneumatic distribution system,build a bench for indoor testing.The main conclusions of this paper are as follows:(1)Taking the urea granules as the model and combining the actual operating conditions,when setting the sowing rate to 30 kg/mu and the operating speed to 12 km/h,the calculated urea mass flow rate is 414 g/s.Under this condition,EDEM-Fluent coupling simulation test was carried out on the state of fertilizer particles after feeding injector.The test results show that the dynamic changes of the model and the changes in the number of particles are generally stable,there is no interruption of the flow,the overall transportation situation is uniform and stable,and the distributor meets the design requirements.Combined with the calculation and design,the main parameters of the proposed pneumatic distribution system are:the diameter of the conveying pipe is 50mm,the bending diameter ratio of the elbow is=1.0,and the overall pressure loss of the system is 3857.609N/m3.(2)In order to design a deep fertilization device with strong versatility and simple structure,the entry angle α is 20 °,the curvature radius is 120 mm,and the entry angle β is 7°.(3)The experiment is based on the wind speed and fertilization rate at the entrance of the feeder.The wind speed at the entrance is set to four levels of 20m/s,25m/s,30m/s,35m/s and 40m/s,and the fertilization rate is set to 0.29kg/s,0.35kg/s and 0.41kg/s.The test results found that when the inlet wind speed ≥30m/s,under different fertilization rate conditions,the average coefficient of variability of each row of this pneumatic distribution fertilizer discharge system is 3.93%,which meets the requirements of fertilization operations.At the same time,the wind speed can be obtained.It is one of the most important influencing factors in the entire fertilizer distribution process of the pneumatic distribution system.Using SPSS to carry out a significant analysis of the impact of the inlet wind speed on the fertilizer discharge situation,it is found that the correlation between the inlet wind speed and the fertilizer discharge situation is significant:when the inlet wind speed is low,20m/s and 25m/s respectively,the amount of fertilizer discharge The difference between the two is significant,and when the inlet wind speed is higher,30m/s,35 and 40m/s,the difference between the amount of fertilizer discharge is not significant,and the amount of fertilizer discharge is less affected by the inlet wind speed.Therefore,to ensure The amount of fertilizer discharged can be controlled,and the fertilizer should be selected at a wind speed ≥30m/s. |
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