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。     

表面辐射对部分填充吸湿性多孔介质的封闭腔体内热湿耦合传递的影响

根据多孔介质热质传递原理, 基于有限元的方法数值分析了具有表面热辐射的部分填充吸湿性多孔介质的封闭腔体内部自然对流流动及热湿耦合传递过程, 探讨了表面发射率、Rayleigh数和Darcy数等参数对封闭腔体内部自然对流流动及热湿耦合传递过程的影响, 研究结果表明, 壁面热辐射的作用可以提高多孔介质内部的温度, 而且随着表面发射率的增大, 多孔介质内部的水分逐步向其右上角迁移和聚集。另外, Darcy数、多孔介质与空气的热导率比对方腔内部多孔介质的热量传递和水分迁移影响较小。     

大型乙烯裂解炉辐射传热的研究

应用概率统计理论尤其是用蒙特卡罗法对裂解炉管外辐射传热过程温度分布多维模型的开发研究,将计算结果应用到新建或扩建大型裂解炉的设计、采购、建设总承包项目和PMC工程项目管理中,可以提高裂解技术水平、降低投资费用并延长裂解炉运行周期。对于已建成并正在运行的大型裂解炉进行完善和优化,使裂解炉平稳运行,并延长裂解炉的使用寿命。     

浮法玻璃熔窑用新型保温材料及其应用

通过对各类浮法玻璃熔窑保温材料的了解,依据保温材料的选取原则,明确玻璃熔窑传热机理后,再利用计算机软件辅助,得到材料的传热系数、冷面温度和热面温度的曲线图。将目前涌现的几种新型保温材料与传统保温材料进行比较,对比分析证明,采用新型保温材料在节能效果和经济性方面取得效果。     

热管余热锅炉在电石炉炉气余热回收上的应用

文章主要介绍了新型高效换热设备--热管余热化炉用于电石炉炉吃余热回收这一特定工况条件。鉴于电石护存在炉气合尘量大、粘性高、尘拉磨损营村严重等同江,文章从设计的角度这一解决这些难题,提出了与一般水管住炉不同的余热回收方式,并且将设计成功应用到某f 20 000kW的开式电石炉炉气余热回收装工上,通过对设备各项适行指标的测定及分析,阐明了热管余伎俩炉用于电石炉炉气条热回收的经济价值及推广应用前景。     

Al_2O_3-H_2O两相流流体强化换热性能研究

将固体颗粒加入到传统换热介质中形成的固-液两相流流体是一种新型的强化换热介质。设计小型卧式直管加热炉试验装置,用粒径为60 nm,150 nm,55μm质量分数为1%的Al2O3-H2O两相流流体做换热试验,在流量为7,8,9 L/min和炉温为80,100,120,140℃情况下使用计算机对加热直管内、外壁温度和进、出口流体温度数据进行采集和分析。研究发现:固-液两相流流体强化对流传热的效果与颗粒的粒径、流体的流速和加热炉炉温有关。     

水冷壁气化炉温度分布及影响因素分析

对气流床水冷壁气化炉炉壁的温度分布及影响因素进行了计算和分析。建立了气流床水冷壁气化炉的三维传热数学模型,运用有限元方法,计算出水冷壁的温度分布,炉壁导热主要通过渣钉完成;探讨了水冷管内工质传热系数、炉内温度、渣钉间距、鳍片厚度、鳍片宽度及熔渣厚度对渣钉、水冷管、鳍片端部和根部等关键部位的最高温度点温度的影响;为了验证热分析的正确性,在实验室的小型气化炉上进行试验,鳍端背火侧温度计算值与实验测量值吻合良好,误差在5%之内;其计算模型和分析结果可为水冷壁气化炉的设计提供相应依据。     

3-D comparative behaviour of discrete transfer and imaginary planes methods for furnace modelling

The discrete transfer and imaginary planes methods are compared for accuracy and computation time in cartesian and cylindrical enclosures filled with grey gas. The reference solutions are given by the classical zone method. Comparisons are done for surface heat fluxes and gas radiative sources. A wide range of surface emissivities and gas absorption coefficients is analysed. In general, the discrete transfer method reveals superior for accuracy but consumes more computation time. The imaginary planes method loses accuracy when a high number of spatial divisions is used, however it is easy to apply.     

乙烯裂解炉衬里的传热计算研究

总结了乙烯裂解炉的衬里传热计算的原理和方法,对衬里传热计算的相关标准进行分析比较,研究了相关参数的取值并给出参考意见,给出计算程序的编制思路.     

加热炉复合砌筑体界面温度的计算机模拟

依据传热学原理 ,建立了连续式加热炉砌筑体界面温度的传热模型 ,并用有限差分法对模型进行求解 ,利用计算机编程进行数值模拟。该方法对于连续式炉窑的设计及其节能分析具有现实意义     

基于热辐射成像建模求解的管式炉炉管温度检测

准确在线检测管壁表面分布式温度是优化管式炉加热工艺的关键所在。以一台工业管式裂解炉为试验对象,结合辐射图像处理方法,开展了管式炉炉管表面温度可视化检测研究。采用基于Monte Carlo的DRESOR法求解具有复杂边界条件的管式炉辐射成像模型,实现了炉管辐射与火焰辐射、炉壁辐射的解耦计算,对炉管表面温度与热通量分布进行了在线监测,并研究了二者随工质流动方向的变化趋势。经过验证,温度测量误差小于2%,测量误差主要出现在最高和最低温区域。该项研究将有助于指导管式炉燃烧调整,改进加热工艺,提高炉管表面受热均匀性,延长炉管工作寿命。     

加热炉炉壁热损失分析模型

从三维导热模型出发,研究了大型工业加热炉炉壁热损失模型,应用迭代法计算炉墙内外壁面与流体的对流传热系数,从而可以准确计算炉墙的热损失。以链条炉排方箱式燃煤炉为实例,验证了加热炉的空气侧对流传热系数、烟气侧对流传热系数及炉墙传热系数的计算方法。     

Heat flux profile of the furnace wall of a 300 MWe CFB boiler

It is important to properly understand and calculate the distributions of the heat flux and the heat transfer coefficient in a furnace for designing a circulating fluidized bed (CFB) boiler, especially for one with supercritical parameters. An experimental study of the heat transfer in a commercial 300 MWe CFB boiler was conducted in this work. The heat flux from the bed to the waterwall was measured by a heat flux meter at four different heights. The influence of suspension density and bed temperature was analyzed by measuring the pressure profile and temperature profile in the furnace. In addition a numerical modeling study on the two phase flow in the furnace was carried out. The results indicate that the density of the solids suspension was non-uniform in the cross section at a certain height, and decreased gradually with increasing furnace height. Consequently, the distribution of heat flux in the horizontal plane was non-uniform and decreased along the height of the furnace. The heat flux showed a decreasing trend near the center.     

A mathematical simulation of radiant heat transfer in a cylindrical furnace

The radiative heat transfer in a cylindrical furnace was investigated both experimentally and theoretically. The flow pattern within the combustion chamber was measured and found to differ from that of an identical cold model for which extensive theoretical and experimental work had been previously carried out. The Monte Carlo Method was used to solve for the radiative transfer part of the non-linear integro-differential equations describing the combustion and heat transfer in a cylindrical furnace. The radiative heat flux distribution obtained from the simulation agreed well with data obtained from a cylindrical test furnace.     

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。     

Numerical simulation on flow, combustion and heat transfer of ethylene cracking furnaces

With the study object of an 100kt/a SL-II ethylene cracking furnace, this paper used Computational Fluid Dynamics (CFD) method to carry out coupled simulation studies on the flow, combustion, radiative heat transfer and thermal cracking reaction processes in the cracking furnace. The standard k–ε two-equation model was applied to turbulence simulation. The finite-rate/eddy-dissipation model was used for modeling of non-premixed combustion of the bottom burners and premixed combustion of the sidewall burners. The Discrete Ordinates (DO) model was applied to the simulation of radiative heat transfer of furnace. The simulation results show the detailed information about velocity, temperature and concentration fields in the furnace and heat flux distribution on the reactor tubes skin. This work will provide a theoretical basis for the optimization of the geometrical structure and operational parameters of the cracking furnace.     

管式加热炉节能的研究进展

以管式加热炉主要结构的节能为出发点,从改造燃烧器及辐射室结构、优化吹灰技术、研发新型清焦技术以及研制新型空气预热器和新型辐射炉管等方面,综述了目前管式加热炉燃烧器、辐射室、对流室及余热回收系统的节能效果的研究情况,其中增强辐射传热和余热回收能力可有效降低排烟温度,提高加热炉效率,因此其对于管式加热炉的节能更有效。最后对今后管式加热炉的节能研究提出展望。     

碳化硅晶体生长炉辐射换热特性的数值模拟

采用C语言搭建了碳化硅(SiC)晶体生长炉三维温度场数值模拟平台,基于柱坐标系构建生长炉物理模型,采用有限体积法离散数学模型,利用S2S(Surface to Surface)辐射模型考察了生长室内的辐射换热特性,提出判断辐射面可视性的最短距离法. 模拟了电流强度1250 A、电流频率16 kHz条件下的生长炉温度场,定量揭示了生长室内的辐射换热强度;采用标准偏差法研究了线圈结构对晶体内部温度及温度梯度均匀性的影响. 结果表明,螺旋电磁加热线圈容易导致生长炉内部温度场呈非轴对称特性分布;辐射热流较导热热流大102~103倍,辐射换热促使生长室内温度分布均匀;螺旋线圈的布置方式使晶体截面温度呈非轴对称分布,造成温度梯度的均匀性变差,晶体生长过程中容易产生热应力,影响晶体质量.     

Moderne Verfahren zur Berechnung des Strahlungsaustausches in brennstoffbeheizten Röhrenöfen

Modern procedures for calculation of radiational heat transfer in fueled tubular furnaces . The zone method due to Hottel, the Monte-Carlo method and the flux method are of great importance for the calculation of radiational heat transfer in combustion chambers, along with simple zero- to two-dimensional models. Only the first three methods can be used for three-dimensional problems. The zone method and the Monte-Carlo method are mathematically exact, while the flux method gives only approximate values. The radiational heat transfer to the pipes of a cracking furnace is calculated by a simple zero-dimensional zone method to show, for example, that simple models often also give reasonable results.