汽阳极多管AMTEC辐射与导热模型的研究

针对研制并改进新一代汽阳极多管碱金属热电转换装置(AMTEC)需要准确计算汽阳极多管AMTEC内的辐射和导热损失,以PX-3A型装置为分析对象,利用RadCAD软件计算了装置内各辐射面之间角系数,角系数计算结果满足完整性要求;以此角系数作为输入数据建立了装置辐射与导热模型,计算了不同负载电阻下装置的输出功率、负载电压和BASE管冷端温度等参数,结果表明计算值与文献实验值相吻合,从而验证了模型的正确性和合理性;最后对不同热端温度对转换效率的影响进行了分析,推荐装置热端运行温度为1123 K。     

用电辐射管改造K型炉

<正> 一、前言辐射管作为一种合理的加热元件已在可控气氛炉等热处理设备上普遍使用。据报道,日本现在热处理主要设备都采用辐射管加热技术,尤以连续渗碳炉和万能炉为多。辐射管加热具有以下特点:①生产中可以更换而不影响生产;③功率分布更加合理;③有利于炉内气氛的流动;     

镀锌板生产线退火炉辐射管燃烧实验研究

建造一座模拟退火炉作为煤气燃烧试验装置，通过模拟不同热值的发生炉煤气在炉内辐射管中燃烧，探索辐射管换热性能和烟气热损失大小的变化规律，为将燃烧半水煤气更换成燃烧发生炉煤气提供技术依据。模拟在线辐射管的运行状态，找出改变助燃空气量和排烟负压对辐射管壁温和炉温的影响，寻求一种最佳的运行方案，从而使生产线达到节能降耗目的。     

低温辐射加热炉

本文阐述了低温辐射加热的基本原理和低温辐射传热及加热温度均匀的技术,以此为基础设计出新型干燥炉——低温辐射加热炉。该炉用同一个热源进行辐射与热风复合加热,它既适用于簿的、形状简单的工件加热,又适用于厚的、形状复杂的超大工件的加热。     

陶瓷辐射管烧成炉的研制

介绍某厂研制的陶瓷辐射管烧成炉及在该厂生产中的应用情况。新型炉比常规马弗炉具有明显的经济效益。     

封闭腔不透明表面辐射传递系数统计分析

基于蒙特卡罗法定义封闭腔内不透明表面辐射换热的辐射传递系数,并与角系数、哥布哈特系数进行比较,发现其在反映综合考虑表面材料物性以及空间几何位置的能量传输特性过程中更具有通用性。统计分析辐射传递系数概率分布和置信度水平,推导封闭腔内辐射传递系数的平均相对和绝对误差公式,为用蒙特卡罗法求解辐射换热中所确定的计算精度和计算工作量提供了参考依据。     

耐高温辐射涂料在减压炉上的节能应用

某企业常减压蒸馏装置加热炉的燃料消耗量占炼油装置燃料消耗的比例高达22.6％,通过分析,在12.0Mt/a常减压蒸馏装置一段减压炉辐射室炉衬表面喷涂耐高温辐射涂料,提高辐射传热能力和热效率,以降低燃料消耗量.一段减压炉采用耐高温辐射涂料技术后,提高了炉膛辐射系数,增强了炉衬反射能力.涂层应用的直观体现是加热炉热效率由9...     

对流传热计算中的烟气辐射放热系数α_1

本文提出锅炉对流传热计算中用到的烟气辐射放热系数α_(?)袭用炉内辐射传热的计算公式有误差,因为所对应的温压不同,应予改正。     

引射式中温燃气辐射管热工性能的试验研究

对吸风式直通型辐射管进行了试验研究,该燃气辐射管是由低压引射式大气燃烧器和石英玻璃辐射管组成。介绍了引射式燃烧器的研制过程及其特点,通过试验对燃气辐射管性能进行了研究,分析了燃气负荷、空气系数,在辐射管内加入插入物这几个因素对辐射管的温度分布及热效率的影响规律,为燃气辐射管的工业化应用提供理论依据。     

余热锅炉辐射受热面辐射系数的影响因素

论述了余热锅炉内辐射传热的影响因素,计算得到了烟气入口温度、三原子气体含量、含尘量、饱和蒸汽压力、有效辐射层厚度、积灰厚度等因素对辐射系数C′的影响关系,以此指导余热锅炉的设计。     

延迟焦化加热炉存在问题分析与整改

惠州炼油420×104t/a延迟焦化装置加热炉采用美国FW公司双面辐射斜面阶梯炉,每台加热炉由6个辐射室、1个对流室组成。每个辐射管程设置单独的一个炉膛。共用的对流室安装在辐射室上,用于原料预热和蒸汽过热。该加热炉运行16月后,出现对流炉管结焦、排烟温度上升、部分炉管堵塞等问题。造成对流段结焦的主要影响因素,是回炼催化油浆以及注水温度相对偏低,导致渣油中沥青质析出;排烟温度高的主要影响因素是炉管结焦与对流段取热不足。对此,增加两排对流管、一排注水管、一排低低压蒸汽过热管。操作方面,主要优化措施有:停止催化油浆进焦化回炼,提高注水温度,注水方式从单点注水改为两点注水;同时平稳操作,减少焦粉携带。通过技术改造与操作优化,加热炉运行平稳,排烟温度显著降低,基本消除了加热炉对流段的结焦因素,加热炉在线清焦周期明显延长。     

A Study of the Radiant Heat Exchange within a Controlled-Atmosphere Furnace

Transient three-dimensional heat transfer between a traversing, structured, and rectangular object and an enclosure is studied. This study investigates the heat transfer process that occurs in brazing an aluminum heat exchanger in a controlled-atmosphere furnace. A model's development is discussed with prescribed enclosure temperature boundary conditions. The program determines the radiant heat exchange between gray diffuse surfaces, and solves the three-dimensional conduction equation for a solid with a radiant heat flux boundary condition using an implicit finite-difference method. The structured object's conduction and radiant thermal properties are described by effective values. It was shown that radiative thermal properties of the traversing object and the enclosure's temperature have a strong impact on the object's temperature history. The effective thermal emissivity was found to influence the object's rate of temperature change. The enclosure's temperatures influenced the object's equilibrium temperature. Also, it was shown that the object's position and rotation can alter its temperature distribution, but not as strong as the effect of boundary conditions and thermal properties. In addition to numerical methods, experiments were performed to further understand the process.     

红外辐射材料的研究及其在武钢工业炉上的应用

从高温工业炉强化炉内辐射传热过程的角度出发,分析了工业炉应用红外辐射材料的重要意义。在红外辐射材料的研究、涂料节能机理的研究和实际应用技术的研究等方面,系统地介绍了武钢的研究和实际应用情况。根据武钢20多年的实际应用经验,针对不同工业炉具体的工况条件,合理选择性能优良的红外辐射涂料,能够取得良好的节能、增产和延长炉子使用寿命的效果。     

轴承套圈余热退火辊底炉生产线

轴承套圈余热退火辊底炉生产线是一高度机械化自动化的特大型加热设备。由于受厂房长度限制，设计成长方形的闭环结构，这是本设计的特点之一。从热镦机出来的红热套圈进入料筐、以及热处理各工序的进行、料筐内套圈的翻卸、空料筐的返回等各个阶段全自动运行，构成一热处理生产线的闭环系统。由于是热装炉，可显著节约能源。本生产线另一特点是：加热段采用煤气辐射管加热，而控制降温段和球化段则采用电热辐射管加热，这可显著降低     

Heating Process Simulation of Steel Coil in Bell‐Type Annealing Furnace

This study examines two important parameters: the convective heat‐transfer coefficient and radiative heat‐transfer coefficient, which have a significant impact on coil temperature in a furnace. A new three‐dimensional model is proposed for convective heat transfer, and the factors affecting the Nusselt number (Nu) are studied using the orthogonal test method. Finally, the relationship between the Nu number and flow rate is determined. Considering the complex geometric structure of a furnace, this study uses the Monte Carlo method to calculate the angle factor and obtains the radiant heat flux using a radiation network diagram. The calculated values are applied to steel coil temperatures for accurate boundary conditions. The results show that the temperature simulated by using the mathematical model is in good agreement with the experimental data obtained with the thermocouple insert experiment.     

1550连续退火、电工钢机组炉内辐射管损坏原因分析及对策

宝钢冷轧厂1550单元连续退火机组及电工钢机组的辐射管发现大量破裂现象，并且这种劣化速度很快，平均每个月损坏10～15根。辐射管的损坏严重影响了机组的产能发挥；从辐射管的材质分析入手研究辐射管破裂的原因；并作出相应的改善对策。     

链条炉排加煤粉复合燃烧锅炉炉膛传热计算基本方程

推导了链条炉排加煤粉复合燃烧锅炉炉膛的物擀平衡方程和上下炉膛的烟气热平衡方程，方程中考虑了上下炉膛间的辐射换热。用直接计算辐射换热量的方法，推导了炉膛的辐射换热方程，这些方程联立求解，可进行该类型锅炉炉膛的传热计算。     

The Conceptual Design of a Radiant Chamber and Preliminary Optimization of a Process Tubular Furnace

The design procedure of a process tubular furnace (or fired heater) can generally be divided into three design stages: the preliminary design of furnace, a detailed thermal and hydraulic simulation of the furnace, and final design solution, and the mechanical solution of the furnace (stress analysis, drawings preparation, etc.). The first design stage (the preliminary design of the furnace and cost prediction) is usually connected with a proposal for the customer when only the basic process and furnace design data are usually known. In this design stage, it is appropriate for the furnace designer to not have much detail for a reliable design method. The procedure for the preliminary design of a radiant chamber is usually a main part of such a design method because the radiant chamber represents a basic and dominant part of the modern process tubular furnace. The conceptual (or preliminary) design of the radiant chamber makes up the main part of this process. The presented method is based on standard, time-tested design methods (e.g., the Lobo-Evans method and Belokon's method). It is shown how these standard global design methods can be (for common operating conditions) suitable, generalized, and simplified. It allows for the purpose of the conceptual radiant chamber design the arrangement of the basic heat transfer equation for the radiant chamber. The derived form of the heat transfer equation then allows one to obtain basic process and geometrical radiant chamber characteristics of the given furnace type (cylindrical, box, etc.) iteratively. A developed radiant chamber calculation connected with standard procedures for the design of the furnace convection parts and stack (together with cost predictions) is used, and the method for a quick preliminary evaluation of the influence of the main design and process furnace parameters (dimensions of radiant chamber and convection parts, average heat flux to radiant tubes, absorbed heat in radiant chamber and convection part of furnace, stack size, and fuel consumption) for the total costs was developed. It allows the optimization of the furnace from an investment, operating, or total cost point-of-view in the preliminary design stage of the furnace. The developed method can also be used for the effective solution of the furnace integration into the process. The application of the developed method is demonstrated through a case study—the optimum design of a furnace for a crude atmospheric distillation unit.     

层燃炉后拱对煤结焦的影响

本文通过理论计算针对低长后拱对煤层的辐射作用进行分析，同时对后拱全覆盖及半裸露两种情况下辐射能的变化作了比较，对于特定用户锅炉改造具有指导意义。