| China’s potatoes acreage and output ranks first in the world.Potatoes planting area will be expanded more than 100 million mu by 2020.So potato precision sowing is the key to promoting potato development in China.Currently,artificial or mechanical planters is mainly cultivation.So that we not achieve fully automation in potato planter,this phenomenon seriously restricted potatoes’ quality and yield.Air-suction planting has many obvious advantages.Not only can achieve precise seeding but also have high operating speed,low replay rate and low leakage rate.However,the existing air-suction planting is only aimed at small and medium grain crops can’t meet potato.The main reasons include: material potato seed characteristics(whole potatos,cut block potatos)have large quality and irregular size;this seeds need high pressure,high speed and large flow;therefore,it is difficult to design and process of fan.In view of this key technical problem,from theoretical and experimental studies were carried out on fan internal structure and airflow field,obtain the structure and operating parameters of fan that meet the potato sowing needs,achieve air-suction planting technology of potato.The main research contents of this article are as follows:(1)Through mechanical and FLUENT simulation analysis,establish a mathematical model that describes inlet fan pressure about internal structural parameters,considering internal structure and external factors of fan.Determine the radius of volute tongue,rotating speed,the distance between volute tongue and impeller t,the inlet installation angle of blade,the outlet installation angle of blade are main factors.(2)Using simulation test methods,Through SolidWorks three-dimensional software to change fan structure model,change the combination of influencing factors under structural parameters corresponding to the fan inlet pressure each time,and analyze the test data through analysis of variance.fan turbine structure with volute radius of 34.45 mm,volute tongue and impeller spacing of 76.50 mm,blade inlet installation angle of 15.47° and blade outlet installation angle of 106.82° was obtained.(3)Verified the aerodynamic performance of new fan through CFD aerodynamic performance test.Verification tests show that aerodynamic performances are total pressure,static pressure,efficiency,shaft power significantly improved.And processing new fan for bench verification tests,the new fan meet the sowing requirements of potato from bench verification test.Average qualified index was 96.1%,multiple-seeding index was 1.8% and missing-seeding index was 1.5%,all within the allowable range and has better sowing effect.The optimized fan can provide continuous and stable negative pressure to the metering device to meet operational requirements.(4)Fan’s bearing outside fan temperature,bearing temperature and bearing temperature reaches a steady state during long time run at high speed from performance evaluation.Analysis signal to determine bearing conditions and failures through bearing mounted on bearing measured vibration signal bearing.Realize the timely feedback on the working condition of fan,so that air-suction potato planter to maintain a good working condition.The relevant research in this paper provides an effective solution to design and research of air-suction potato planter fan.It provides theoretical support and technical reference for design improvement and optimization of potato planter,and promotes the further development of mechanized planting of potato. |
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