三种主食热量的测定——燃烧热测定实验的应用

以大米面、小麦粉、玉米面三种常见主食为原料,对三种主食的热量进行测定,探讨主食与不同人群之间的健康问题。实验表明,不同种类的主食所含热量不同,因此适合的人群就不同。实验结果表明大米面、小麦粉和玉米面的燃烧热分别为21083.58 J·g-1、20184.24 J·g-1和19531.89 J·g-1。根据主食热量的大小人们可选择适合自己健康饮食方式。     

氧弹卡计测定食用大豆油热值

为了能够直接测定食用大豆油的燃烧热,采用药用胶囊装取大豆油试样进行测定。利用SHR-15型精密量热计系统地测量了大豆油的燃烧热。采用SWC-ⅡD精密数字温差仪记录时间与温度变化数据,运用Origin6.0数据处理软件并结合雷诺温度校正法得到?T,计算出氧弹卡计的热容和食用大豆油的燃烧热值,此法准确、简便、实用,可用于日常检测工作。     

3种抗病毒药利巴韦林燃烧稳定性研究

选择3种抗病毒药利巴韦林作为研究对象,利用氧弹量热计测定燃烧热,热重分析利巴韦林的燃烧稳定性,建立3种抗病毒药的多指标综合评价体系,以期为抗病毒药燃烧稳定性研究提供科学依据。     

高氯酸羟胺燃烧热的测定及生成热的计算

在转动弹量热计中测定的高氯酸羟胺与草酸二乙酯混合后的燃烧热为-790.07±0.19kcal·mol~(-1);高氯酸羟胺的燃烧热为-78.46±0.22kcal·mol~-;计算出高氯酸羟胺的生成热为-64.98±0.19kcal·mol~(-1)。     

4种阿昔洛韦片燃烧分析

选择4种阿昔洛韦片作为研究对象，利用氧弹量热计测定燃烧热，4种阿昔洛韦片燃烧热大小顺序为：厂家2阿昔洛韦片>厂家1阿昔洛韦片>厂家4阿昔洛韦片>厂家3阿昔洛韦片。4种阿昔洛韦片测试样燃烧热在7 511～104 013.77 J/g之间，CV%<4%,从热重分析结果、阿昔洛韦片燃烧性方面分析，4种阿昔洛韦片燃烧稳定性排序为：厂家3阿昔洛韦片>厂家2阿昔洛韦片>厂家1阿昔洛韦片>厂家4阿昔洛韦片。不同厂家4种阿昔洛韦片分为两大类。熵聚类分析应用于抗病毒药物的分类学研究，这项研究为大规模开发阿昔洛韦片药品资源以及分类研究提供有力地科学依据。热重分析阿昔洛韦片的燃烧稳定性，建立4种阿昔洛韦片的多指标综合评价体系，为阿昔洛韦片燃烧稳定性研究提供有力地科学依据。     

燃烧热测定实验的进一步改进

对传统的氧弹式量热法进行了改进,并且采用计算机控制燃烧热测定实验系统。结果表明,该系统具有精确度高、结果准确、响应快、实验时间大大缩短、且可单独操作完成等特点。整个过程采用人机对活方式,操作简单,易于掌握。     

清开灵胶囊、清肺抑火片、莲花清瘟胶囊燃烧分析

选择清开灵胶囊、清肺抑火片、莲花清瘟胶囊作为研究对象,测定3种清热解毒药燃烧热、燃烧稳定性,建立3种清热解毒药的多指标综合评价体系,为热重分析方法研究食品药品燃烧稳定性评价与研究提供有力的科学依据.     

燃烧热的测定网络课程的教学设计

燃烧热的测定网络课程软件的教学设计,用于辅助学生进行网上预习,设计注重学生参与实验及数据处理过程,达到了相应的训练目的.本文介绍了该网络课程教学设计的开发和应用.     

从燃烧热的测定实验谈物理化学实验教学的育人理念

文章以燃烧热的测定实验为例,围绕三个方面谈物理化学实验教学的育人理念:一是在绿色化学理念指导下,对经典实验教学内容进行优化与完善;二是从量化思维与实验技能训练两方面阐述实验教学过程中学生化学素养的培养;三是结合实验数据的自动化采集及处理,培养学生应用现代信息技术处理数据的能力。凸显绿色化学、提升化学素养、提高综合素质的育人理念贯穿了物理化学实验教学的全过程。     

端基对饱和直链烃燃烧热的影响

本文通过对燃烧热的研究发现不同端基饱和直链烃类的燃烧热都很好地满足同系线性规律；同时也发现端基给电子的能力越小，燃烧热曲线的斜率越大，说明碳链中相应的C－C键的键长越长，键能越小，化合物的生成焓越大。     

煤自燃的分子结构模型探讨

煤自燃主要是由于煤表面活性结构与氧之间相互作用的结果 .通过对煤、氧分子结构特性的分析 ,并根据类似有机结构与氧发生化学反应的条件及过程分析 ,探讨了煤分子表面易于氧化自燃的活性结构 ,归纳出 7种在常温常压下就能与氧发生化学反应的煤分子表面活性基团及其氧化反应热 ,利用煤自然发火实验对推断出的活性基团氧化反应热进行了验证 .在威斯化学结构模型和本田化学结构模型的基础上 ,提出了能够对煤自燃进行描述的煤分子结构模型 ,对煤自然发火机理及其过程的研究具有一定的参考价值 .     

Modelling of combustion characteristics of high ash coal char particles at high pressure: Shrinking reactive core model

Combustion of a single-particle high ash coal char at elevated pressure has been analyzed. A fully transient shrinking reactive core model incorporating a simple mechanistic kinetic scheme is used to study the combustion characteristics of high ash coal char. The model includes heat and mass transfer phenomena, reaction kinetics and intra-particle details. Finite volume method (FVM) has been used to solve partial differential equations representing fully transient conservation equations. The char combustion model predicts the mass-loss profile and burnout time of the char particle at different temperature and oxygen concentration. The computed results are found to agree well with the published experimental findings of pressurized combustion of high ash coal char. The effects of bulk temperature, total pressure and initial particle size on combustion characteristic and burnout time have been examined through model simulation.     

Large-eddy simulation of coal combustion in 15 MW pilot-scale boiler-simulation facility

High-fidelity modeling provides a useful approach to investigate the multiscale multiphysics mechanism in the pulverized coal combustion. This research focuses on understanding the pulverized coal combustion in a pilot-up facility: General electric (GE) 15 MW pilot-scale boiler simulation facility (BSF). The heat flux to the boiler water wall, O₂ concentration, and gas temperature are the quality of interest (QoI's) for this research, as they are the most important parameters for designing a full-scale pulverized coal boiler. Even the heat flux in boiler is largely determined by the heat transfer mechanism, and other detailed multiphysics mechanisms, including multiphase turbulent flow, radiation heat transfer, ash deposition, coal devolatilization, and oxidation, also need to be accounted. This work applies large-eddy simulation (LES) code on high-performance computing facility to simulate pulverized coal combustion in BSF. The physics-based submodel that contains the significant sensitivity for QoI's has been identified using the detailed impact factor analysis on this high-fidelity modeling. Results indicate that the most sensitive submodel on QoI's is the wall-heat-transfer coupling with the ash-deposition model, which allows us to prioritize to improve this submodel in the LES simulation. Thus, ash deposition and wall-heat-transfer processes have been modeled and integrated into coal combustion numerical simulation. The simulation results show quantitative agreement between the simulation with experimental data regarding gas temperature, O₂ concentration, and heat-flux profile across the exposed boiler walls. Another implication of this research is to demonstrate a positive societal impact of extreme computing and accelerate the development of new combustion technology using a capable exascale computing technique.     

造纸黑液和煤泥制备水煤浆的技术研究

将干燥的块状煤泥研磨至不同粒度的煤粉,与造纸黑液按一定比例配制成水煤浆,考察其综合性能指标.当黑液添加量为7.2%,煤粉粒度小于160目时,制备的水煤浆浓度为67.44%,流动性为A级,稳定性达到20d保持良好.改变黑液的pH值,研究其配制的水煤浆,发现废液pH对水煤浆的成浆性没有太大的影响.由于造纸黑液中含有大量有机质,因此还可提高同等条件下水煤浆的燃烧热值.利用GB 213-87测定所制备水煤浆的恒容高位发热量为21.63MJ/kg,低位发热量为15MJ/kg.     

热分析试验评价节煤剂对煤粉燃烧过程的影响

为探究节煤剂产品特性,本文利用热分析方法讨论了3种节煤剂对煤粉燃烧过程的影响。结果表明,添加不同节煤剂,#1、#2、#3煤样着火点分别降低了9.2 ℃、11.2 ℃和88.9 ℃,并且提高放热效率。燃尽指数表明,节煤剂使#1和#2煤样燃尽性能提高,而#3燃尽性能变差。动力学计算表明,节煤剂能够降低煤粉从着火点到最大燃烧速率阶段的反应活化能,从而提高该燃烧过程的反应速率。     

煤粉无焰富氧燃烧的数值模拟方法进展

无焰富氧燃烧是煤粉清洁燃烧技术的前沿发展方向之一,可在捕集高浓度CO₂的同时显著降低NOx排放,并提升富氧燃烧稳定性和热力性能。计算流体力学(CFD)作为燃烧研究的重要手段之一,具有快捷、成本低和数据丰富等优点,有效促进了无焰富氧燃烧技术发展。基于笔者团队对煤粉富氧燃烧和无焰燃烧的多年研究积累,对近十几年来煤粉无焰富氧燃烧CFD模拟方法和模拟研究进展进行了总结:首先强调了煤粉无焰燃烧的试验和数学定义,其由于存在非均相反应而区别于气体燃料无焰燃烧;然后详述了煤粉无焰富氧燃烧CFD模拟方法进展,包括模拟流动、传热、燃烧和污染物生成方面的子模型和机理,其中考虑强烈烟气卷吸的可实现k-ε湍流模型、P1或DO辐射模型及针对富氧气氛修正的WSGG气体辐射模型、CPD挥发分析出模型、考虑湍流与化学反应交互的有限速率EDC均相燃烧模型、针对无焰及富氧燃烧开发验证的均相反应机理、考虑气化反应的多步表面焦炭非均相燃尽模型、含氮化学详细反应机理氮转化模拟、动态自适应反应机理加速算法等可显著提高煤粉无焰富氧燃烧的模拟精度和计算效率。总结了煤粉无焰富氧燃烧在基准对照试验、微观反应区域分析、宏观反应特征、污染物生成及大型化锅炉概念设计方面的模拟研究情况;最后以大涡模拟、燃烧模型、高精度反应机理及动态自适应反应机理、工业应用优化等角度展望了煤粉无焰富氧燃烧CFD研究的发展方向。     

低变质煤富氧低温干馏试验研究

用富氧代替空气与煤气燃烧提供热源,利用燃烧废气与低温干馏过程产生的干馏煤气混合形成高温循环气,对煤进行富氧干馏。试验结果表明,在不改变现行低温干馏炉结构的情况下,富氧干馏完全可行,可大幅提高煤气的有效成分,降低氮含量,煤气热值是空气助燃干馏的2倍以上,煤气放散量减少约3/4。     

Modelling coal combustion: the current position

At the present time, computer models for coal combustion are not sufficiently accurate to enable the design of combustion plant or the selection of a coal based on combustion behaviour. Most comprehensive combustion models can predict with reasonable accuracy flow fields and heat transfer, but usually with a much lesser degree of accuracy than the combustion of the coal particles through to char burnout. Many research programmes are aimed at developing a much more accurate predictive tool for assessing coals specially fired in burners or furnaces employing a range of NO_x abatement technologies. Some of the current developments in CFD coal combustion modelling are outlined here. Particular attention is paid to the first step, where the devolatilisation pre-processor code is used to compute the pyrolysis rate, the yields and the composition of volatiles and char. These parameters are used as inputs to the devolatilisation and volatile combustion sub-models, where various options can be used, and also the char burnout sub-models. The accuracy of the sub-models is examined using data from four well-studied coals, three from the UK and one from the US. The main network devolatilisation codes are compared with experimental data. Two char combustion models have also been investigated in order to compare char burnout predictions and the development of char morphology and surface area during burnout are considered. The applications of these sub-models to two combustion situations were considered. These involve reactions in a drop tube furnace and a low NO_x industrial burner and in both cases, the model predictions were compared with experimental measurements.     

中国动力煤的着火温度与着火热的分布规律

为了寻求动力煤成分分布与煤质着火及稳燃特性之间的函数关系,根据燃烧学的热力着火理论,对国内大型电站煤粉锅炉燃用的166个典型的煤质分析数据进行了数学分析。分析了固态碳(C_gt)和当量气态碳(C_qt 3.67H_ar)比值随V_daf的分布规律及其对煤质着火的影响;根据文献中77个煤质的一维沉降炉实验数据,拟合出煤粉的着火温度与V_ad及A_ad的函数关系,计算分析了本文大数据样本煤质的着火温度及着火热的分布规律,提出将着火热和着火温度作为煤质着火特性的图像分辨新方法。据此分析了各类煤质的着火与稳燃特性。结果表明,本方法能明确地定量区分不同类煤质和同类煤质的着火特性差异,且在理论上给出符合宏观规律的合理解释。