平壁,球形壁砌体非稳态热损失计算

本文对平壁、球形壁砌体的非稳态传热计算用有限差分法进行了分析,提出平壁多层砌体的外表面温度、界面层温度以及砌体内部温度场计算公式。提出球形壁砌体的温度场和外表面层温度计算公式。用计算机进行了实例计算,结果表明,外表面层温度计算值与实测值误差仅为8.6％,吻合较好。     

强对流铝材热处理炉过程控制模型研究

以S厂铝卷退火炉为研究对象,建立了强制循环热处理炉的数学模型。计算时将其复杂的加热过程划分为定热流和恒温过程两个阶段。分别采用不同的处理方法,由两个阶段的组合模拟出整个加热过程。本模型主要包括料卷、炉墙等几个小模型。用差分方法得到料卷非稳态导热的高离散化线性方程组,并采用“逐线迭代法”进行求解。多层炉墙一维传热不同材料的相邻结点间采用“调和平均”法处理。该模型计算得到的料卷温度分布与实际给定及操作曲线相吻合,证明本模型适用于低温强制对流的热处理炉。     

多层炉墙的稳态热损失计算

本文讨论稳态条件下多层炉墙的热计算。利用割线法、抛物线法和幂级数法三种解析逼近法进行多层炉墙的热计算,并举实例示出了用三种解析逼近法进行热计算的程序。与传统的试算法相比,本文的解析热计算法运算速度快,精度高。     

耐火材料导热系数与炉内温度的关系及其炉壁温度计算

多层耐火材料结构式工业炉炉壁耐火材料的导热系数随其炉内温度的变化而不同。针对平板炉壁型、矩形截面炉壁型和圆筒形截面炉壁型3种不同形状结构的工业炉，介绍了多层耐火材料结构式工业炉炉壁耐火材料在炉内温度变化条件下炉壁温度分布的计算方法。给出了实际计算例。     

白介素-2联合生脉注射液治疗肝癌栓塞化疗后临床观察

导出了在稳态导热下单层、2层、3层以及多层平壁耐火材料炉衬及圆筒形炉衬单层、2层耐火材料炉衬的经济厚度计算公式，可供炉子设计及节能改造时参考。     

圆筒形苯加氢改质炉炉尾超温治理研究

对存在尾部严重超温的圆筒形化工炉，通过应用多喷口旋流燃烧技术，大大改善炉内温度分布和传热状况，不仅彻底解决起温问题，而且提高炉子热利用率１０％，节约了能源。     

室状加热炉金属加热过程的数值模拟

本文对室状炉内金属加热过程进行二维、非稳态传热的数值计算。根据一定的加热工艺,建立计算模型。该模型可计算任一时刻金属内部的温度分布及主要的加热参数,可使实际加热工艺得到优化,给出最短加热时间及具体的热工参数。     

微型计算机在测量热处理炉热损失中的应用

在节能工作中,为减少热处理炉炉墙的导热引起的热损失,须首先知道热处理设备的热损失状况。在对企业开展能量平衡的工作中,碰到了计算炉墙导热损失中的关键问题是层间温度的估算。因为层间温度无法直接测量,根据“能量平衡统一规定”的要求,层间温度采用试算法。试算法盲目性大、计算繁杂、且要凭经验。采用该法估算一面炉墙     

室状中热炉金属加热过程的数值模拟

本文对室状炉内金属加热过程进行二维、非稳态传热的数值计算。根据一定的加热工艺，建立计算模型。该模型可计算任一时刻金属内部的温度分布及主要的加热的参数，可使实际加热工艺得到优化，给出最短加热时间及具体的热工参数。     

卧式燃油燃气炉炉胆传热计算方法的比较研究

对卧式燃油燃气锅炉或加热炉,炉胆传热计算是热力计算中的重要计算,其主要目的是确定炉胆出口烟温。本文对已有的卧式内燃燃油燃气锅炉炉胆传热计算公式进行了比较,提出了适合加热炉炉胆传热计算的方法和简化算法。     

Estimation for inner surface geometry of furnace wall using inverse process combined with grey prediction model

In this work the inner surface geometry of a cylindrical furnace wall is estimated using inverse process method combined with grey prediction model. In estimating process a virtual area extended from the inner surface of furnace wall is used for analysis. The heat conduction equation and the boundary condition are first discretized by finite difference method to form a linear matrix equation; the inverse model is then optimized by linear least-squares error method and the temperatures of virtual boundary are obtained from a few of measured temperatures in furnace wall using the linear inverse model; and finally the temperature distribution of system is got by direct process and the inner surface geometry of furnace wall can be estimated accordingly. The result shows that using inverse process combined with grey prediction model the geometry can be exactly estimated from relatively small number of measured temperatures. Moreover, the effects of measurement error, location, and number of measured points on the estimation for inner surface geometry of furnace wall are discussed in detail.     

Experimental investigation on simultaneous measurement of temperature distributions and radiative properties in an oil-fired tunnel furnace by radiation analysis

The paper reports experimental investigations on simultaneous measurement of temperature distribution and radiative properties in an oil-fired tunnel furnace by radiation analysis. Two color CCD cameras were used to obtain visible thermal radiation in the furnace. A radiation imaging model was established by the calculation of radiative transfer equation in the furnace. The temperature distribution and radiative properties can be obtained from the inversion of the radiative imaging model. The validity of radiative imaging model was verified by the numerical analysis of cavity radiation and isothermal system radiation, and the accuracy of reconstruction method was validated by simulation reconstruction. The experimental analysis was divided into two parts. Firstly, the temperatures of wall surface were calculated from the radiative image of refractory wall and compared with the measured temperature of a thermocouple. The difference between the two methods was only about 20 K. Secondly, the temperature distributions in the furnace, absorption coefficients of combustion medium, and emissivities of refractory wall were reconstructed. Because of a single burner in the tunnel furnace, the temperature distributions in the XY vertical sections in the furnace were with temperature higher in the center and lower near the refractory wall surface, and the temperatures decreased along the length of the tunnel furnace. The measured emissivity of refractory wall showed that the refractory material of RPA-MC30 is with high reflectivity in visible spectrum.     

用不同模型研究炉壁黑度对炉膛内热交换的影响

给出了加热炉和锅炉炉膛内炉气分别为灰体和非灰体的零维段法模型,并用这些模型分别研究了加热炉和锅炉内炉壁黑度变化对炉内热交换的影响。结果表明,当假设加热炉内的炉气为灰体时,无论炉壁是否为辐射绝热面,金属所得的热流都不随炉壁黑度的变化而变,但当加热炉内的炉气为非灰气体时,金属所得的热流随炉壁黑度的增大而增加,这与高辐射率涂料在加热炉上的应用实践是一致的。当炉气温度为定值时,锅炉内的炉壁温度随壁炉黑度的增大而升高,而炉壁吸热量不随炉壁黑度的变化而变。图5参7     

Effect of Furnace Thermal Configuration on Optical Fiber Heating and Drawing

ABSTRACT

The thermal configuration of the draw furnace, which involves the wall temperature profile, the temperature level, and the length of the heated zone, is an important aspect in high-speed optical fiber manufacture. This article presents a computational study on the effect of the furnace thermal configuration on the draw process and on physical quantities such as velocity and temperature difference across the preform/fiber, tension, and neck-down profile. Considering a cylindrical graphite furnace, the study solves a conjugate problem, which involves both the moving silica glass rod or fiber and the inert gases in the furnace. The flow and heat transfer in the two regions is linked due to the boundary conditions at the surface of the glass. Force balance conditions are used to determine the neck-down profile. A fairly versatile finite-difference numerical scheme is employed to consider different temperature distributions along the furnace wall, as well as a range of heating-region lengths. Besides the flow and thermal transport, the tension in the fiber and thermally induced defects that affect fiber quality are also calculated. A range of fiber draw speeds is also considered, and the effect on the variables that determine the fiber characteristics is studied.     

300MW直流炉顶棚进口集箱引出管系的改进

由于炉膛燃烧不理想导致水冷壁出口管的热偏差,使进入顶棚进口集箱的引入管的工质产生了较大的温差。这种热偏差在顶棚入口集箱形成了轴向壁温差,使顶棚入口集箱引出管座承受了附加的超过其工作温度下许用应力的热膨胀载荷,从而使刚度较大的集箱上层接管产生了较大的附加弯曲应力,最终导致了上层接管根部的永久性变形和角焊缝裂纹。分析这种应力产生的原因,在实际中对顶棚进口集箱引出管上层接管结构进行了改进,在运行中收到了很好的效果。     

环形加热炉热工过程CFD数值模拟及其应用

借助CFD商业软件CFX，考虑流动、辐射、燃烧等，对宝钢环形加热炉的热工过程进行了数值模拟，得到了炉膛内的温度、速度矢量等热工参数的分布图。通过简化处理，对环形加热炉各控制段内的加热过程进行了模拟分析，并根据所得到的管坯表面辐射热流、热电偶温度及管坯表面温度研究了各个段总括热吸收率的分布情况，主要分析了总括热吸收率在管坯圆周方向、长度方向以及各个段之间的变化规律。     

基于燃烧与水动力耦合模型的锅炉蒸汽管超温特性研究

提出一种基于燃烧与水动力耦合模型的锅炉蒸汽管壁温度数值模拟方法,对某660 MW超临界切圆燃烧锅炉壁温进行了计算分析。以均匀外壁温为边界条件,利用Fluent软件模拟了煤粉气固流动、燃烧和辐射等过程,获得了炉内不同位置受热管的传热热流。再以热流分布为边界,采用MATLAB软件建立了工质流动及气-壁-汽换热方程组,Fluent软件重新计算的壁温边界。通过编写模型间的网格映射函数,实现壁温的耦合计算。研究表明:壁温计算值与实测值的最大相对误差在2%以内;炉膛出口残余旋转使水平烟道左侧和右上方热流较大,高温再热器和末级过热器的外壁温沿炉宽方向呈双峰分布;高温再热器整级受热管出口壁温的峰谷差值远高于末级过热器,实际运行中应特别注意高温再热器靠烟道左侧管屏外圈管子向火侧弯头处的超温。     

2008t/h四角燃烧煤粉锅炉烟温偏差实炉测试分析

大型四角切圆燃烧锅炉的烟、汽温度偏差对其安全运行具有重要影响。在2008t/h锅炉上,对不同负荷工况下炉膛上部屏区烟温及屏式过热器壁温进行了测试。结果表明,汽温左高右低,大致成W型分布形态,而烟温呈M型分布,与汽温分布状态峰谷反向对应。认为炉膛上部空间残余旋转形成沿屏区宽度烟气流量的不均匀分布,因而烟气对受热面的冲刷强度不同,导致屏间烟气换热量存有差异,这是烟、汽温偏差产生的根本原因。