Effects of heating rate on fast pyrolysis of cut filler of cigarette

为考察升温速率对卷烟烟丝快速热解行为的影响,采用热重-质谱联用技术对卷烟烟丝在不同升温速率(200 K·min~(-1)~800 K·min~(-1))下的热解特性进行研究,并建立了不同升温速率下卷烟烟丝的快速热解动力学模型。结果表明:(1)随着升温速率的升高,烟丝各主要成分热分解温度区间的叠加程度、热解速率以及释放特性指数均呈递增趋势,且有不同程度的热滞后现象。(2)引入升温速率校正因子的动力学模型能够克服热滞后所引起的动力学参数偏差,可以更好地预测不同升温速率下卷烟烟丝的快速热解行为。(3)高升温速率下,热解烟气产物中质荷比(m/z)为56(丙烯醛)、79(吡啶)、84(烟碱)、94(苯酚)和117(吲哚)的化合物释放量减小。在高升温速率下卷烟烟丝的快速热解特性与卷烟燃烧的真实状态更为接近,建立的卷烟燃烧数学模型更加准确。In order to study the effects of heating rate on fast pyrolysis of cut filler of cigarette, TGA(Thermogravimetric Analyzer) combined with QMS(Quadrupole Mass Spectrometers) was applied to investigate the pyrolysis characteristics of cut filler of cigarette at different heating rates(200 K·min~(-1)-800 K·min~(-1)), and a kinetic model for the fast pyrolysis of cut filler at different heating rates was developed. The results showed that: 1) With the increase of heating rates, thermal decomposition overlap region, mass loss rate and devolatilization index of each main component in tobacco were raised. Meanwhile, thermal lags of different extents were also observed. 2) The kinetic model overcame the deviation of kinetic parameters caused by thermal lag via introducing a heating rate correction factor, and predicted the fast pyrolysis behaviors of cut filler at different heating rates more accurately. 3) The release of pyrolysis products, such as acrolein(m/z=56),pyridine(m/z=79), nicotine(m/z=84), phenol(m/z=94) and indole(m/z=117) decreased with the increase of heating rate. The fast pyrolysis characteristics of cut filler are closer to the real state of cigarette combustion and the developed mathematical model for tobacco pyrolysis kinetics is more accurate at high heating rate.福建省中烟工业有限责任公司科技创新项目“卷烟燃烧数学模型的建立及其在卷烟减害中的应用”(FJZYJH2013025

用于质子交换膜燃料电池的高温无机质子传导材料研究进展

质子交换膜是质子交换膜燃料电池(PEMFC)的核心部件,其主要作用是传导质子。无机质子传导材料作为一种新型的质子传导介质,近年来逐渐引起了人们的关注。本文主要介绍了小分子磷酸、无机...福建省科技厅重点项目(2016H6024

Comparison between REA model and thin layer drying model based on strip drying kinetics

为了获得最适用于烟草干燥的动力学模型,达到设计、优化和控制烟草干燥过程的目的,采用湿度发生器联用热重技术(TGA)研究了65 ℃ &RH; 15%, 75 ℃ & RH 10%和85℃& RH 5%条件下片烟的干燥动力学行为,并利用REA (Reaction engineering; approach)以及8种经验或半经验的薄层干燥模型分别对不同温湿度条件下的片烟干燥行为进行模拟。结果表明:①干燥温度越高,相对湿度越小时,片烟; 的干燥速率越快,平衡含水率越低;②REA模型预测的片烟干燥动力学曲线与实验曲线能够很好地吻合,尤其是在含水率由20%降至12%阶段;8种薄层干燥; 模型中Two; term模型拟合出的R~2值最大,均方根误差(RMSE)最小,是描述片烟干燥行为较合适的模型;③薄层干燥模型仅仅是获得特定温湿度条件下相对应的动; 力学参数,而REA模型是将温度和湿度作为变量引入模型中,模型中的动力学参数可以描述任意温湿度条件下的片烟干燥动力学行为;④REA模型构造简单,预; 测准确快速,较Two term模型更具有普适性、实用性。In order to select a kinetic model best fit for the design, optimization; and control of tobacco drying process, the drying kinetic behavior of; tobacco strips under the conditions of 65 ℃ & RH 15%, 75 ℃ & RH10%, 85 ℃; & RH 5% was investigated with a humidifier combined with TGA; (Thermogravimetric analyzer). The drying behavior of tobacco strips was; simulated by REA (Reaction engineering approach) model and eight; selected thin layer drying models (semi-empirical or empirical). The; results showed that: 1) With the rise of temperature and decrease of; humidity, the drying rate of strips raised and the equilibrium moisture; content of strips lowered. 2) The drying kinetic curves predicted by REA; model well agreed with experimental curves, especially at the stage when; the moisture content decreased from 20% to 12%. Among eight thin layer; drying models, Two term model was the best for predicting the drying; behavior of strips with the highest R~2 (determination coefficient) and; the lowest RMSE (root mean square error). 3) Thin layer drying model; reflected only the kinetic parameters corresponding to specified drying; conditions, while in the REA model the temperature and humidity served; as variables, it enabled the kinetic parameters in REA model to describe; the drying kinetic behavior at any drying condition. 4) REA model was; simple in structure, fast and accurate in prediction, more universal and; practical than Two term model.福建中烟工业有限公司科技项

Numerical Simulation of Cigarette Smoldering

为了描述卷烟阴燃过程的二维数学模型,用fluEnT软件模拟了卷烟的阴燃过程,包括卷烟燃烧过程中发生的水分蒸发反应,烟草热解和氧化反应,以及质量传递、能量传递和动量传递。分析了不同时刻温度分布,烟气中氧气、一氧化碳、二氧化碳和水蒸气的浓度分布,并将模拟得到的卷烟阴燃线性燃烧速度(lbr)和最高阴燃温度值与实验值进行对比,其中实验测得的lbr为0.38 CM/MIn,而模拟值为0.44CM/MIn,最高温度的实验值和模拟值均在900~1000 k之间,说明模拟值与实验值基本相符。To develop a 2D mathematical model of cigarette smoldering process, the process was simulated with Fluent software, which included water evaporation, tobacco pyrolysis and oxidation reaction, and the transfer of mass, energy and momentum.The temperature distribution at different time and the concentration distribution of O2, CO, CO2and water vapor in the smoke were analyzed.The simulated value of linear burning rate(LBR) of smoldering was of 0.44 cm/minute, the experimental LBR value of 0.38 cm/minute; both the simulated and experimental values of maximum smoldering temperature were in the range of 900-1000 K,which indicated that the simulated values and the experimental values were basically agreed with each other

Research progress in cigarette combustion model

综述国内外有关卷烟燃烧模型的研究进展。认为应在深入研究卷烟燃烧过程和机理的基础上,建立全面系统准确的卷烟燃烧数学模型,以便为工艺改进提供科学依据。Research progress in cigarette combustion model was reviewed.Suggestions were proposed that comprehensive,systematic and accurate mathematical model of cigarette combustion need to be established based on further research in combustion mechanism to improve blending technique

破碎岩土压缩试验中用的柔性边界加载实验机

本实用新型涉及一种柔性边界加载实验机，包括：试验机框架、三个位于试验机框架外的加压装置和压力室缸体，还包括至少一个固定在上盖板的下表面处的超声波位移测量装置，侧面包裹有乳胶膜的试样位于压力室缸体内，其侧面与压力室缸体内壁之间形成一围压压力室，该围压压力室内充满液体或气体；所述轴压活塞环放置在试样上，其外径与压力室缸体的内径相等；所述轴压加载胶囊位于轴压活塞环与上盖板之间，所述的位于实验机框架的下盖板内的平衡压活塞环通过平衡压传力杆与轴压活塞环固定连接在一起，其下方还设置一平衡压加载胶囊；所述三个加压装置分别连通轴压加载胶囊、平衡压加载胶囊及围压压力室中的液体或气体

STUDY AND MANUFACTURE OF FLEXIBLE BOUNDARY LOADING TESTING MACHINE

现有的土力学试验机都是刚性边界加载,也就是等位移边界加载.这种试验机基本上是以研究均匀材料为目的,并且,它主要用于研究材料内部一点的应力-应变状态和强度准则.而实际的土石混合体和破碎岩体内部包含有结构面和节理面等,它们是非均匀、非连续的,在外力的作用下其内部的应力分布是不均匀的.对于这种材料,其真正的受力条件是等应力边界条件.为此,介绍了一种自行研制的三轴试验机--柔性边界加载试验机.该试验装置可以更好地从均匀加载的角度研究非均匀、非连续介质的变形及破坏规律.对这种试验机的原理和设计作了说明;推导出了轴压、围压、平衡压之间的协调关系;同时,还介绍了超声波位移测量系统以及压制试样的装置和压制过程

用于岩土体现场水平推剪试验的装置

本实用新型涉及一种用于岩土体现场水平推剪试验的装置,该装置包括一放置在试体顶端的前枕木和一固定在试坑内侧壁上的后枕木,前、后枕木之间放置一安装有压力表的千斤顶,试体两侧的空隙中分别填充一个密封的金属箱体,该金属箱体接触试体的一面为乳胶膜,其它五个侧面均为金属板;所述两个金属箱体的内部空间充装液体或/和气体,并通过一连通软管连通;所述金属箱体与低压软管的一端连通,该低压软管的另一端与气压表、降压阀和高压气瓶相连;本实用新型保证了所施加的侧向压力的可控性,使得每次的试验结果之间具有更好的可比性,将三维问题转化为真正的平面问题,从而简化试验结果的分析