河南农业科学 ›› 2023, Vol. 52 ›› Issue (6): 172-180.DOI: 10.15933/j.cnki.1004-3268.2023.06.018

• 农业信息与工程·农产品加工 • 上一篇    

温度和含水率对烟叶热物理特性的影响及其预测模型建立

陈家鼎1,何蓉2,肖庆礼2,袁明2,谭奇忠2,彭奎2,魏硕1,李生春1,2   

  1. (1.河南农业大学烟草学院,河南 郑州 450002;2.重庆中烟工业有限责任公司,重庆 400060)
  • 收稿日期:2022-10-10 出版日期:2023-06-15 发布日期:2023-07-11
  • 通讯作者: 李生春(1972-),男,重庆铜梁人,工程师,主要从事卷烟工厂技术改造、设备管理、卷烟生产等工作。E-mail:lisc02@cncqti.com
  • 作者简介:陈家鼎(1999-),男,河南南阳人,在读硕士研究生,研究方向:烟草调制加工。E-mail:1315746297@qq.com
  • 基金资助:
    重庆中烟工业有限责任公司资助项目(YL202202)

Influence of Temperature and Moisture Content on Thermophysical Properties of Tobacco Leaves and Establishment of Prediction Models

CHEN Jiading1,HE Rong2,XIAO Qingli2,YUAN Ming2,TAN Qizhong2,PENG Kui2,WEI Shuo1,LI Shengchun1,2   

  1. (1.College of Tobacco,Henan Agricultural University,Zhengzhou 450002,China;2.China Tobacco Chongqing Industry Co.,Ltd.,Chongqing 400060,China)
  • Received:2022-10-10 Published:2023-06-15 Online:2023-07-11

摘要: 为全面了解烟叶不同组分的热物理特性,为烘烤、回潮和复烤等热加工工艺设计提供参考,采用热探针法分别测定10~70℃、含水率5%~30%的烤后烟叶叶片及主脉热扩散系数、导热系数、比热容,并分析变化规律,借助MATLAB软件以指数函数形式拟合温度、含水率与烟叶热物理特性参数值之间的相关性,构建烟叶热物理特性参数的经验数学模型,并通过试验进行验证。结果显示:(1)叶片和主脉的密度随含水率的增大而增大,含水率在5%~30% 时,叶片密度为562.79~684.84 kg/m3,主脉密度为908.83~1 045.51 kg/m3;(2)温度和含水率的提高都会使叶片和主脉热扩散系数增大,且含水率贡献率更大,叶片热扩散系数为0.092 33~0.219 00 mm2/s,主脉热扩散系数为0.088 67~0.149 00 mm2/s;(3)叶片和主脉导热系数随温度和含水率的增大而增大,叶片导热系数为0.088 13~0.435 37 W(/m·K),主脉导热系数为0.160 70~0.388 83 W(/m·K);(4)叶片和主脉比热容主要与含水率呈正相关,叶片比热容为1 520.623 44~3 123.569 52 J(/kg·K),主脉比热容为1 618.828 08~2 563.703 20 J(/kg·K);(5)对拟合经验模型进行验证,决定系数(R2)介于0.93~0.99。综上,叶片和主脉的热物理特性差异较大,拟合的指数函数可以作为计算叶片和主脉对应热物理特性参数的经验数学模型。

关键词: 烟叶, 叶片密度, 主脉密度, 热物理特性, 数学模型, 温度, 含水率

Abstract: In order to comprehensively understand the thermophysical properties of different components of tobacco leaves and provide reference for the design of thermal processing technology such as baking,moisture regain and redrying,the thermal diffusion coefficient,thermal conductivity and mass specific heat capacity of post⁃baking tobacco leaves and main veins were measured by the thermal probe method under the temperature from 10 to 70℃ and moisture content from 5% to 30%,respectively,and the variation pattern was analyzed.The correlation between temperature,moisture content and the values of thermophysical properties of tobacco leaves was fitted in the form of exponential function with the help of MATLAB software to construct an empirical mathematical model of the thermophysical properties of tobacco leaves,which was verified by experiments.The results showed that,(1)The density of tobacco leaves and main veins increased with the increase of moisture content.When the moisture content was 5%—30%,the density of leaves was 562.79—684.84 kg/m3,and the density of main veins was 908.83 to 1 045.51 kg/m3;(2)The increase of temperature and moisture content would increase the thermal diffusion coefficient of tobacco leaves and main veins,and the contribution rate of moisture content was greater.The thermal diffusion coefficient of leaves was 0.092 33—0.219 00 mm2/s,and the thermal diffusion coefficient of main veins was 0.088 67—0.149 00 mm2/s;(3)The thermal conductivity of tobacco leaves and main veins increased with the increase of temperature and moisture content.The thermal conductivity of leaves was 0.088 13—0.435 37 W(/m·K),and the thermal conductivity of main veins was 0.160 70—0.388 83 W(/m·K);(4)The mass specific heat capacity of tobacco leaves and main veins was mainly positively related to the moisture content. The mass specific heat capacity of tobacco leaves was 1 520.623 44—3 123.569 52 J(/kg·K),and the mass specific heat capacity of main veins was 1 618.828 08—2 563.703 20 J(/kg·K).(5)For verifying the fitted empirical model,R2 was between 0.93 and 0.99.In summary,the thermophysical properties of leaves and main veins differed greatly,and the fitted exponential function could be used as an empirical mathematical model for calculating the corresponding thermophysical property parameters of tobacco leaves and main veins.

Key words: Tobacco, Leaf density, Main vein density, Thermophysical properties, Mathematical model, Temperature, Moisture content

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