新型热法磷酸燃磷塔传热分析与计算

在介绍新型燃磷塔结构的基础上,提出了计算其理论燃烧温度和烟气排放温度的工程方法。同时分析了燃磷量、过剩空气系数及燃磷塔结构型式等因素对其传热特性的影响。结果表明,在空气过剩系数或空气量不变时,最高燃烧温度和烟气排放温度随燃磷量增加呈单调递增趋势;而在燃磷量一定时,过剩空气系数越大,最高燃烧温度越低,烟气排放温度越高。     

热法磷酸生产过程多尺度模拟

从燃烧热力学、反应-传质机制及全流程综合角度,分析了工艺和结构参数对燃磷塔燃烧特性的影响,探究了黄磷燃烧的“三传一反”机理。结果表明,空气过剩系数取低了会导致燃磷塔中心温度偏高,取高了会导致能源浪费,故取中间值1.5;喷枪角度的增大可以提高预热回收率,但会影响塔体温度分布,故喷枪角度为41°时较佳,喷枪个数为3时,塔内最高温度会下降,燃烧区域增大,优于双喷枪的塔型,但成本上升。该研究优化了燃磷炉热能回收效率,可为工厂内部热法磷酸优化方案提供可靠借鉴。     

热法磷酸生产余热利用装置及其燃烧温度研究

通过对国内外燃磷塔的分析比较，设计了一种具有辐射换热面的新型燃磷塔。实际运行结果表明，该塔不仅能保证磷酸的正常生产，而且可以副产出相当数量饱和蒸汽，实现高效率的余热回收。燃磷塔内的传热以辐射为主，为此提出了一种计算理论燃烧温度和烟气排放温度的工程方法，通过该法计算的理论值和实测数据吻合较好，能满足工程计算的精度要求。     

热法磷酸燃磷塔的节能改造与传热特性研究

针对热法磷酸生产中一方面要求外部供热 ,另一方面又浪费自身燃烧热的现状 ,提出了利用汽包和燃磷塔回收余热的新工艺 ,设计了具有膜式水冷壁的新型燃磷塔 ,使每燃烧 1t黄磷能副产 0 .5MPa蒸汽 5 .96t。借助数值模拟的方法 ,分析了燃磷量、过剩空气系数及结构型式等对燃磷塔传热特性的影响     

膜式水冷壁结构燃磷塔的开发与传质传热的数值模拟(Ⅰ)模型建立

针对热法磷酸生产中一方面要求外部供热,另一方面又浪费自身燃烧热的现状,提出能回收余热的新工艺,开发成功膜式水冷壁结构新型燃磷塔.建立了考虑新型燃磷塔内流动、燃烧、传热过程的三维数学模型,通过数值模拟得到塔内湍流场、温度场和组分浓度场的分布.模拟结果显示,燃磷塔内存在明显的涡流射流结构,磷的燃烧主要在喷磷枪雾化角范围内,塔内最高燃烧温度约为1790 K,出现在喷磷枪轴线上偏离燃磷塔中心的一侧.烟气出口温度约为970 K,与测量值符合较好.     

热法磷酸燃磷塔现状及其与普通工业锅炉的比较

热法磷酸燃磷塔的节能改造是目前磷化工行业的一个重要课题。本文在介绍国内外燃磷塔现状的基础上，将新型燃磷塔与普通工业锅炉进行了比较，比较结果表明，两者在本体机构、传热特性及设计目的等方面存在着差别，这些差别对燃磷塔的优化设计具有一定参考价值。     

用计算法放样制作燃磷水化塔塔体

用计算法放样制作燃磷水化塔塔体,保证了制作质量,满足了热法磷酸工艺要求,节省材料,缩短工期,节省资金.     

回收燃磷水合过程酸雾制试剂磷酸

近几年来,随着我国科技事业的迅速发展,迫切要求我厂在生产工业磷酸的同时,生产试剂磷酸。据了解,国内生产试剂磷酸多为石墨塔设备,而用不锈钢塔设备生产试剂磷酸,还未见报导。我厂热法生产磷酸,系采用不锈钢制燃磷水合塔,为了增加试剂磷酸的生产,提高产品质量。我们分析了磷酸的生产过程,认为在黄磷燃烧水合过程中,生成了大量的酸雾,漂浮于气流之中,未与不锈钢塔壁接触,因而不夹代不锈钢被腐蚀下来的金属离子。故把酸雾冷凝下来得到酸的质量是很高的。为此,在不锈钢制燃磷水合塔后的气流管道上,安装了一台冷却面积为5M~2的石墨冷却器,把酸雾冷凝为液体磷酸。     

新型强制水循环热法磷酸燃磷塔余热回收技术研究

针对传统热法磷酸燃磷塔存在的问题,提出了一种新型的具有强制水循环的盘管式热法磷酸燃烧塔,并分析讨论了其结构、原理和设计要点。该塔在保证产磷酸量的同时,副产了更多的工业蒸汽,提高了余热利用效率,运行更加安全可靠、经济环保。     

膜式水冷壁结构燃磷塔的开发与传质传热的数值模拟（Ⅱ）传热特性影响因素分析

利用已建立的数学模型考察了燃磷量、过剩空气系数、壁面温度、辐射吸收系数对新型燃磷塔的最高燃烧温度、烟气排放温度、壁面最大热流和平均热流的影响.模拟结果表明,无论过剩空气系数固定还是空气流量固定,随燃磷量的增大,最高燃烧温度、烟气出口温度、壁面平均热流和最大热流都呈上升趋势.在燃磷量不变情况下,最高燃烧温度、壁面最大热流和平均热流均随过剩空气系数的增大而减小,但烟气出口温度缓慢增加.壁面温度对最高燃烧温度、壁面最大热流和平均热流影响不明显,但烟气出口温度随壁面温度的升高而增加较大.辐射吸收系数对最高燃烧温度和壁面最大热流影响很大,随辐射吸收系数的增大,最高燃烧温度和烟气出口温度会下降,而壁面最大热流和平均热流会上升.     

加热炉酸露点问题探讨

分析了酸露点腐蚀产生的原理及影响因素,列举了计算露点温度的几种常用方法,并将计算值与工业实际控制值进行比较.认为已有研究成果多针对锅炉燃煤过程,对加热炉燃油过程的计算只有一定的借鉴意义.在此基础上提出应综合各种因素准确测算酸露点,得到具有普遍应用性的计算方法,提高了加热炉燃烧和燃料利用的效率.     

An experimental study on high temperature and low oxygen air combustion

High temperature preheated and diluted air combustion has been confirmed as the technology, mainly applied to industrial furnaces and kilns, for realizing higher thermal efficiency and lower emissions. The purpose of this study was to investigate fundamental aspects of the above-mentioned combustion experimentally and to compare with those in ordinary hydrocarbon combustion with room temperature air. The test items were exhaust gas components of CO, NO_x, flame shape and radical components of CH, OH and C₂, which we measured with gas analyser, camera and ICCD (Intensified Charged-Coupled Device) camera. Many phenomena, as a result, which appeared in the combustion with the oxidizer, low oxygen concentration and extremely high temperature air, such as expansion of the flammable limits, increased flame propagation speed, looked very strange in comparison with those in existing combustion technology. We confirmed that such extraordinary phenomena were believable through a hot-test experiment.     

REMOTE SPECTRAL SENSING OF TEMPERATURE PROFILES IN FLAMES

Knowledge of the temperature profile of the gases produced by the combustion of fossil fuels with air is a desirable step in the thermal protection systems. These gases are generally associated with high temperatures and steep temperature gradients. The measurement of temperature profiles of combustion products are often hard to make using thermocouples and other immersed pyrometers because such probes may have to be immersed in inaccessible and possibly destructive media. Determination of gas temperature profiles from multi-frequency radiative measurements seems an attractive alternative. This could be accomplished by radiative heat transfer probing and the application of the principle of inversion, where inversion is the process of inferring the internal parameters of a system of outside measurements, without the interruption of the combustion system itself.

This paper discusses the development of models to retrieve the temperature distribution in a flame system by remote spectral sensing. Mixed Gray-Gas models were developed to calculate water vapor and carbon dioxide standard emissivities. The evaluation of combustion system spectral radiant flux was simulated and a model was developed and successfully tested for the application of temperature inversion.     

焦炉燃烧室跨越孔温度变化规律的研究

采集相邻5个炭化室跨越孔温度变化的数据,研究了跨越孔温度换向后的稳定性及经历时间的变化规律。跨越孔温度换向后最初急剧下降,之后呈上升趋势,与交换时间具有线性相关关系。换向后15min时的稳定性优于换向后10min时的稳定性。跨越孔温度随结焦周期时间变化的幅度较大,趋势也较明显,呈倒W型双峰曲线变化。对燃烧室温度进行分段拟合,可得到平均温度的最大、最小值及出现时间。     

计算流体力学——改进硫酸装置性能的工具

阐述计算流体力学(CFD)的原理,介绍CFD在硫酸装置中的3则应用案例:冷换热器冷端管板的温度分布,转化器内置热换热器旁路管内的气体分布,焚硫炉内温度及气体分布。通过用CFD彩色编码图详细地形象化表示硫酸装置内部发生的情况,得出结论:分流气体换热器可消除在冷换热器和SO3冷却器中SO3侧的酸冷凝并使SO2侧所夹带的少量酸雾气化,在大型设备中两种不同温度的气流混合不一定适宜,CFD可使硫磺燃烧过程的模拟、焚硫炉几何结构的优化成为可能。     

A comprehensive fractal char combustion model☆

The char combustion mechanisms were analyzed and a comprehensive fractal char combustion model was developed to give a better understanding and better predictions of the char combustion characteristics. Most of the complex factors affecting the char combustion were included, such as the coupling effects between the pore diffusion and the chemical reactions, the evolution of the char pore structures and the variation of the apparent reaction order during combustion, the CO/CO2 ratio in the combustion products and the correction for oxy-char combustion. Eleven different chars were then combusted in two drop tube furnaces with the conversions of the partly burned char samples measured by thermogravimetric analysis. The combustion processes of these chars were simulated with the predicted char conversions matching very well with the measured data which shows that this char combustion model has good accuracy. The apparent reaction order of the char combustion decreases, stabilizes and then increases during the combustion process. The combustion rates in the oxy-mode are general y slower than in the air-mode and the effect of the char-CO2 gasification reac-tion becomes obvious only when the temperature is relatively high and the O2 concentration is relatively low.     

UNIT ORGANIZATION OF CERAMISTS FOR RESEARCH PROMOTION

Some of the phenomena of heat transfer in glass furnaces are reviewed; it is suggested that circulation of the hot non-luminous products of combustion may be an important factor in heat transfer in furnaces, and evidence is given as to the existence and the rapidity of this circulation.