Study On Physical Properties And Storage And Transportation Conditions Of Solid Fuels Formed From Straw Of Sunflower

Sunflower is a kind of crop planted in a large area in north China.As a kind of agricultural waste,sunflower straw has a great use value after the harvest of sunflower crops in rural areas.In this paper,the physical characteristics of sunflower straw hot-pressed solid fuel were studied,the storage environment of the straw was simulated,relevant experimental data were obtained,the appropriate storage environment of the straw and the storage period of the straw were summarized,and the internal finite element analysis of compression was studied,which provided the basis for the design theory of related processing and utilization equipment.The research results show that:(1)In this experiment,straw thermal compression equipment was used to analyze the physical properties of sunflower straw under different temperature,pressure,moisture content and granular test parameters.The contribution of various factors to fuel density in the forming of solid fuel in sunflower straw compaction blocks(from large to small order)is the water content(59.26 %),pressure(32.96 %),temperature(1.59 %),and granularity(0.59 %).At temperatures of 130 to 150 °C,pressures of 80 to 100 MPa,moisture content of 4 % to 8 %,and granules of 0.16 to 0.63 mm,the good molding effect is conducive to large-scale production.(2)In the response surface test design,the generalized distance method was used to optimize the test model,and the optimum molding conditions were: 6.65 % moisture content,140 °C temperature,and 98.17 MPa pressure.Under this test condition,Density,durability,and breakability reached 1.19 g.cm-3,99.81 %,and 99.92 %,respectively,and the optimal results were good.(3)In the storage process of sunflower straw forming fuel,different temperature and humidity have a great influence on the storage effect.During the storage process of temperature and relative humidity in different storage environments,the physical properties of sunflower straw forming fuel changed.The difference of temperature and humidity between North and South is analyzed,and the average annual humidity temperature in seven major regions of China is calculated.In northern China,biological particles can be stored in the open air for a longer period of time under the average annual temperature of 10 to 25 °C and 40 RH to 60 RH storage conditions.(4)Transportation motion analysis of molded straw materials was carried out using simulated vehicle transportation vibration table.In order to determine the effect of road transport on quality defect of sunflower straw forming in the course of transportation,the effect of actual condition on the article was obtained in the laboratory.The vibration frequency of automotive transport materials is between 0.5 and 5.0 HZ.The test results show that the frequency of vibration and material defect are low in the course of packing materials with iron box.(5)In the study of the internal transfer force and heat transfer characteristics of the molding tube,the process of hot pressing molding of sunflower straw is simulated using the finite element ABAQUS software.The software analysis results meet the basic conditions required for molding,and the temperature of the heating sleeve is conducted at 100 °C.Within one minute temperature transfer to the internal temperature field is basically in accordance with the time requirements.Under 100 MPa compression at given pressure,the effect of stress on the bottom surface of the molded straw is stronger than that on the upper surface.The pressure on the lower surface is large,the molding effect is good,the smooth and flat,and the hardness is stronger than the upper surface.Through the experimental study,the process parameters of the hot pressing molding of sunflower straw were optimized,the suitable storage environment of the forming straw and the packaging materials of transporting solid fuel were analyzed,and the internal force and heat transfer characteristics of the cylinder were studied.It provides a reference for other biomass solid forming processing,storage and transportation equipment.