基于混合正交试验的生物质旋压成型多目标优化

Multi-objective Optimization of the Biomass Densification Process Based on Mixed-level Orthogonal Array Design

生物质是重要的可再生能源资源,通过旋转挤压制备固体生物质成型燃料具有工艺简单、生产率高等优势,但目前该技术应用仍存在着设备能耗高、制品品质不稳定等问题。以具有强制喂料系统的生物质旋压成型设备为研究对象,通过混合水平正交试验,研究了喂料频率、压轮转速、模具长径比、菌渣添加比例和原料含水率对成型设备的生产率、吨料电耗和成品密度的影响规律,并进行了多目标评价优化。结果显示各试验因素均对成型设备的生产率、吨料电耗和成品密度有显著影响,但不同评价指标下的最优组合不一致;多目标优化获得的最优组合为:喂料频率60 Hz,菌渣比例5%,模具长径比6,原料含水率10%,压轮转速65 r/min。试验得到该组合下成型设备的生产率为5.2 t/h,吨料电耗为38.5 k W·h/t,成品密度为0.84 g/cm3,具有较好的综合生产性能。

Biomass is an important renewable energy resource. The preparation of solid biomass briquette fuel by rotary extrusion has the advantages of simple process and high productivity,but there are still some problems in the application of this technology,such as high energy consumption of equipment and unstable quality of products. Taking the biomass spinning molding equipment with forced feeding system as research object,this study analyzed the influence of feed frequency,wheel speed,ratio of mold length to diameter,proportion of bacteria residue and raw material moisture content on productivity of the densification device,energy consumption and product density using mixed horizontal orthogonal testusing and carried out the optimization of multi-objective evaluation. Results showed that all the experimental factors had significant impact on productivity of the densification device,energy consumption and product density. But the optimal combination of different evaluation index was not consistent. The optimal combination of multi-objective optimization result was feed frequency 60 Hz,wheel speed 65 r/min,ratio of mold length to diameter 6,proportion of bacteria residue 5% and raw material moisture content 10%. Testing results indicated that productivity of this combination was 5.2 t/h,energy consumption was 38.5 k W·h/t,and the product density was 0.84 g/cm^3.