微波加热干燥煤泥热质传递及其能耗特性分析  

Heat and mass transfer and energy consumption for microwave drying of coal slime

作　　者：王光宇[1,2] 张锴[1,2] 张凯华[1,2] 张东柯[3] WANG Guangyu;ZHANG Kai;ZHANG Kaihua;ZHANG Dongke(Beijing Key Laboratory of Emission Surveillance and Control for Thermal Power Generation,North China Electric Power University,Beijing 102206,China;Key Laboratory of Power Station Energy Transfer Conversion and System(North China Electric Power University),Ministry of Education,Beijing 102206,China;Centre for Energy(M473),The University of Western Australia,Western Australia 6009,Australia)

机构地区：[1]华北电力大学热电生产过程污染物监测与控制北京市重点实验室,北京102206 [2]华北电力大学电站能量传递转化与系统教育部重点实验室,北京102206 [3]西澳大学能源中心(M473),澳大利亚西澳大利亚6009

出　　处：《化工学报》2023年第6期2382-2390,共9页CIESC Journal

基　　金：国家自然科学基金联合基金重点项目(U1910215)。

摘　　要：采用微波加热方法考察了煤泥干燥过程基本特征及其热量和质量传递特性,阐述了不同阶段动力学和能耗变化基本规律。结果表明煤泥微波干燥可以分为预热升温、恒速干燥和降速干燥三个阶段,其中自由水主要在预热升温和恒速阶段去除,而结合水则在降速阶段去除。恒速和降速干燥阶段的动力学特征可以采用线性模型和修正的Page模型(Ⅰ)分别描述,进而获得所选样品在降速阶段的表观活化能为3.23 W/g。样品在恒速干燥阶段脱水能耗(2.94~5.90 kJ/g)明显低于预热升温和降速干燥阶段,且脱水能耗随着微波功率(500~800 W)增大或初始质量(150~300 g)增加而逐渐降低。The basic characteristics of the coal slime drying process and its heat and mass transfer characteristics were investigated by microwave heating method,and the basic laws of dynamics and energy consumption changes in different stages were expounded.The results show that the process of microwave drying of coal slime may be divided into three stages,i.e.,preheating stage,constant-rate drying stage and decreasing-rate drying stage.The free water within coal slim is removed mainly in the both preheating stage and constant-rate drying stage,whilst the bound water is removed in the decreasing-rate drying stage.The linear model and modified PageⅠmodel can be used to describe the corresponding kinetic processes in the constant-rate and decreasing-rate stage,respectively.Furthermore,the apparent activation energy of the selected sample in the decreasing-rate stage is obtained as 3.23 W/g.The energy consumption in the constant-rate drying stage ranges from 2.94 kJ/g to 5.90 kJ/g,which is significantly lower than that in the preheating or decreasing-rate drying stage.The energy consumption is decreased gradually with the increase of microwave power ranging from 500 W to 800 W or initial mass from 150 g to 300 g.

关 键 词：煤泥 微波 干燥 传递过程 动力学 能耗 

分 类 号：TQ536[化学工程—煤化学工程]