污泥干燥模型选择及Weibull分布模型求解与分析  

Selection of sludge drying model and the solution and analysis of Weibull distribution model

作　　者：谷志攀[1] 周思琦 孙辰 阳季春[1] 杨朝宽 陶乐仁[3,4] GU Zhipan;ZHOU Siqi;SUN Chen;YANG Jichun;YANG Chaokuan;TAO Leren(College of Architecture and Civil Engineering,Jiaxing University,Jiaxing 314001,China;College of Biological,Chemical Science and Engineering,Jiaxing University,Jiaxing 314001,China;School of Energy and Power,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering,Shanghai 200093,China)

机构地区：[1]嘉兴学院建筑工程学院,嘉兴314001 [2]嘉兴学院生物与化学工程学院,嘉兴314001 [3]上海理工大学能源与动力工程学院,上海200093 [4]上海市动力工程多相流动与传热重点实验室,上海200093

出　　处：《农业工程学报》2023年第5期166-174,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金青年基金(31901407);浙江省大学生科技创新活动计划(新苗人才计划)(2022R417009);嘉兴市科技计划项目(2022AD10022);嘉兴市哲学社会科学规划课题(JSKGH2022120)。

摘　　要：为了研究污泥薄层干燥的动力学模型、明确薄层干燥模型选取原则、分析模型参数影响因素及在干燥中应用,该研究搭建了污泥干燥试验台,对不同干燥温度(50、75、100、125℃)、不同风速(0.5、1.0、1.5、2.0 m/s)与不同污泥厚度(5、10、15、20mm)的污泥进行干燥试验,利用Weibull分布模型对其干燥动力学曲线进行模拟并分析,建立了风温、风速和污泥厚度与模型参数的定量关系。从原模型与改进模型、因变量与自变量转换、多参数模型及初始条件等4个角度分析,选择Lewis、Page、Two-term exponential和Weibull分布模型进行拟合分析,发现污泥的热风干燥过程服从Weibull分布模型(R2=0.994~0.997),是典型的降速干燥过程,降速阶段存在第一、第二降速段,模型的尺度参数(α)和形状参数(β)均与热风温度、风速和污泥厚度有关;第二降速段扩散系数大于第一降速段扩散系数,第一降速段活化能变化范围为12.91~17.12 kJ/mol,第二降速段活化能变化范围9.56~15.05kJ/mol。研究结果可为污泥干燥工艺参数优化及干燥设备研制提供参考。Sludge contains a lot of water,organic pollutants,and toxic substances after sewage treatment.The proportion of sludge recycling has reached 85%in developed countries,such as Europe and the United States,of which about 60%has been used to improve the soil or crop fertilizers,but less than 10%in China.Among them,the moisture content of sludge can be reduced to realize the recycling and harmless treatment of sludge for land resource utilization.Thermal drying can be utilized to change the chemical structure by heating,and further remove the vicinal and bound water in the sludge.Then,the lower water content of sludge can be obtained to meet the requirements of the agricultural resource utilization of the sludge.The drying kinetic models of sludge were mainly derived from agricultural thin-layer drying.It is unclear on the physical significance of fitting the various parameters in the traditional empirical or semi-empirical drying models.It is a high demand to effectively combine sludge drying and heat-mass transfer during drying.This study aims to establish and then select the dynamic model for the thin-layer drying of sludge,in order to determine the influencing factors of parameters and application.The drying experiments were also carried out at temperatures(50,75,100,and 125℃),wind speeds(0.5,1.0,1.5,and 2.0 m/s),and the sludge thicknesses(5,10,15 and 20 mm).A Thin-layer drying model was proposed for the selection.The drying dynamic curve was simulated using Weibull distribution model.The quantitative relationship was established between the wind temperature,wind speed,thickness,and model parameters.The result demonstrated that the simple model was selected in the thin layer drying model.The original and modified model should not be selected concurrently,in order to avoid the selection of the model that transformed the dependent variable and the parameter,together with the model failing to meet the requirements of the initial conditions.The Weibull distribution model better described hot-air drying.The moisture

关 键 词：干燥 污泥 动力学模型 Weibull分布模型 有效扩散系数 活化能 

分 类 号：X705[环境科学与工程—环境工程]