Design Of Ultrasonic Vibration Biomass Fuel Molding Device And Experimental Research On Molding Proces

As one of the renewable and environmentally friendly energy sources to replace fossil energy,the development and utilization of biomass fuels can meet the demand of green and low-carbon development and avoid environmental pollution and environmental damage,which is a favorable way to achieve"carbon neutrality"in China.In this study,we designed an ultrasonic vibration biomass fuel molding device based on the material characteristics of corn and rice straw,and studied the physical properties of biomass fuel by single-factor test method and quadratic regression rotational combination test method,and the main research contents and results are as follows:(1)Corn and rice straw material characteristics analysisIn this paper,industrial analysis(initial moisture content,volatile fraction,ash,fixed carbon),elemental analysis(C,H,O,N,S),and chemical component analysis(lignin,cellulose,hemicellulose)were performed for the curing and molding raw materials,and the effects of the results on the ultrasonic vibration biomass fuel molding process were analyzed.The results showed that the percentage of ash in corn straw was 5.74%,which was low and belonged to low ash fuel.The fixed carbon content accounted for 12.82%higher than that of rice straw,due to the higher degree of lignification of corn straw,resulting in a relatively high fixed carbon content;there was no significant difference in the elemental content of both corn and rice straws,with the S elemental content of corn straw accounting for 0.28%greater than that of rice straw at 0.31%.Crop straw has the characteristic of low sulfur element content,and has less influence on SO2 in the atmospheric environment during fuel utilization;the lignin content of corn straw is19.17±0.13%,which is higher,due to the higher degree of cellular lignification of corn straw than that of rice straw.(2)Ultrasonic vibration biomass fuel forming device design and ultrasonic oscillator modal simulation analysisBy analyzing the mechanical differences between ultrasonic-assisted curing molding and traditional biomass compression molding technology,the structural design of the ultrasonic vibration biomass fuel molding device was determined,and the hydraulic control system of the molding device,ultrasonic vibration auxiliary system(ultrasonic generator+ultrasonic oscillator)and other major mechanical structures were designed.The three-dimensional structure of the ultrasonic vibration biomass fuel molding device was optimized,and the processing and assembly of the ultrasonic vibration biomass fuel molding device was completed;and the modal simulation analysis of the key component ultrasonic vibrator was carried out by ANSYS finite element analysis software.(3)Single-factor experimental study of ultrasonic vibration corn and rice straw mixing ratio compression moldingUsing corn and rice straw as molding and compressing raw materials,we analyze the effects of straw mixing ratio,straw particle size,moisture content,single particle mass,molding pressure,ultrasonic compression time and ultrasonic power on the evaluation indexes of biomass molding fuel density,relaxation density,anti-breakage and anti-damage strength,and determine the range of molding parameters to provide a basis for the subsequent ultrasonic vibration biomass fuel molding process.(4)Experimental study of orthogonal rotational combination of ultrasonic vibration biomass fuel molding process parametersBased on the single-factor test,five factors and five levels were determined,and the mathematical regression model of each influencing factor with the density and briquetting resistance of the formed fuel was established by the quadratic orthogonal rotating combination test method,and the significance of the model was verified by ANOVA.The results showed that the main and secondary influences on the density of biomass forming fuel briquettes were forming pressure,ultrasonic power,ultrasonic compression time,corn stover mass ratio,and water content;the main and secondary influences on the shatter resistance of biomass forming fuel briquettes were ultrasonic compression time,forming pressure,water content,corn stover mass ratio,and ultrasonic power.The regression model predicted that when the optimal combination of parameters was 26.62%of corn straw mass,11.81%of water content,4.06 MPa of molding pressure,31.21 S of ultrasonic compression time,and 241.40 W of ultrasonic power,the optimal biomass briquetting fuel was 1328.56 kg/m~3 with 93.87%of shatter resistance under this condition.