Abstract:In this paper, based on steady-state the multi-furnace linings heat transfer theory, introduced the multi-layer furnace linings of the intramural temperature and thermal density is calculated, using VB programming environment visual programming, the establishment of the thermal conductivity refractory material database , in favor of layers, and types of parameters such as material selection, enter the hot surface temperature and thickness on each layer, to calculate various parameters of the corresponding furnace lining. In practice, the performance stable, attractive interface, the design of industrial furnace lining has a strong guiding role.
Key words:Thermal density; VB; Thermal conductivity; Intramural temperature
图1 软件流程图
3.2 数据库的建立
采用常用的Access建立常见耐火材料的导热系数数据库,仅需一张包含材质名称、系数计算式、特征系数a和b的表。
3.3 软件系统的模块设计
该程序提供了内衬1-5层的五种选择,内壁温度设置300-2000℃范围。热面朝向包括热面垂直、向上及向下对应的炉墙、炉顶及炉底三种选择。
内衬材质选择时,采用调用VB中MSFlexGrid控件显示材质名称和表达式,双击选择材质的同时,将两个特征系数a和b赋值给对应的数组。
1)计算原理
建立多层循环,假定炉墙外壁温度为t(1)=tw+1,由公式(1)和(2),求解出热流密度qs,再根据热流密度公式(3)和导热系数公式(4)或(5),求解出t(2)、t(3),直至tn。求得的t(n)与内壁温度tn比较,两者误差满足给定的条件时,结束循环。
2)程序代码(部分)
‘定义数组
Dim cs As integer
Dim ak As Single
cs=val(Text1.text) ‘根据Option控件选择层数,赋值给text1.text,再传递给cs
ReDim s(1 To cs+1) As Variant '声明动态数组作为临时变量,各层厚度mm
ReDim t(1 To cs+1) As Variant '层间温度℃
ReDim a(1 To cs+1) As Variant '导热系数特征系数a