Simulation Optimization And Experimental Research Of Straw Returning Machine Based On Discrete Element Method

China is a large agricultural country.Agriculture is the basis of the national economy.The development of agriculture and rural economy directly affects the sustainable development and social stability of the whole national economy.In recent years,farmers rarely use straw as fuel because of the improvement of the people's living standards.The livestock and animal husbandry farms have gradually replaced the model of family farming.The demand for straw is gradually reduced,and the cost of straw collection is too high.In the season of harvest,farmers burn the straw in the field after the harvest and treatment,which not only causes a lot of waste of resources,but also causes pollution of the environment.Aiming at the problems of serious tool wear,large energy consumption and poor working quality,a kind of energy saving straw returning machine is designed in this paper,and the key parts are designed.Based on discrete element method,the interaction between straw,soil and rotary tiller was simulated and field experiments were carried out.The main contents of this paper are as follows:(1)The key parts of the rotary tiller are designed in detail by adopting the intermediate transmission mode in the structure design of the straw returning machine.In this paper,a lightweight rotary tilling blade with holes is designed with six sections of double helical arrangement.Surfacing welding is used at the edge of rotary tillage cutter,which greatly prolongs the life of rotary tillage cutter.The stiffening rib is designed between the shank and the side cutting surface,which makes the rotary knife stronger,and effectively solves the phenomenon that the side cutting surface of the rotary tiller is easily broken.(2)Based on the discrete element method of EDEM software,the simulation model of the interaction between straw,soil and rotary tiller was established,and the interaction of straw,soil and cutting tool was analyzed from the angle of soil and orange rod movement and rotary tillage knife force,and the soil smoothness was obtained.Straw burying rate and energy consumption.In this paper,three factors and three levels of response surface test were carried out,and the test data were processed and analyzed by Design Expert-Version software.According to the quadratic regression fitting model,the power consumption was drawn,respectively,according to the factors of the advance speed,the rotation speed of the cutter shaft and the depth of rotary tillage.The response surface analysis diagram of straw burying rate was used to obtain the optimal working parameters of the rotary tiller roller and to verify the rationality of the tool roll design.(3)The amount of straw and moisture content were measured.According to the optimal parameter combination obtained by response surface analysis,the field experiment of straw returning machine was carried out,and the rationality of simulation was verified,and compared with the traditional straw returning machine.The results show that the designed straw returning machine has the advantages of wide width,stable tillage depth,straw burying rate,broken soil rate and soil smoothness,which meet the design requirements,and are higher than that of the traditional straw returning machine.Good effect,high efficiency and low power consumption.