不同孔洞形式多孔砖当量导热系数模拟分析

Simulated analysis of equivalent thermal conductivity of porous bricks with different hole forms

依据导热系数概念,对当量导热系数进行定义。通过热模拟有限元分析软件Fluent,研究模拟分析过程中的步骤与技巧,针对单一多孔砖进行热工性能的模拟,对比分析影响多孔砖孔洞形式的6大因素即孔型、矩形长宽比、孔排数、孔列数、孔洞排列方式、孔洞率,分析6种因素对多孔砖当量导热系数的作用情况及影响原理,结果表明,孔型的选取应采用矩形孔;进行孔洞优化设计应在规范容许范围内增大矩形孔的长宽比,同时宜适当增加多孔砖的孔排数或孔列数;孔洞排列应采用交错布置的方式,且保证矩形孔长边垂直热传递方向;应在规范容许条件下尽量增大多孔砖孔洞率,并且确保力学强度达到使用需求。

The concept of equivalent thermal conductivity is introduced into the analogical thermal conductivity coefficient.With the help of the finite element thermal simulation software Fluent,the method and operation used in the simulation analysis are mastered,and the thermal performance of single porous brick is simulated and analyzed.Through the comparative analysis of six factors of porous brick's pore form,i.e.pore shape,rectangular length-width ratio,pore row number,pore arrangement pattern and pore rate,the influence degree and mechanism of the six factors on the equivalent thermal conductivity of brick body are explored.The results show that the pore shape should be rectangular.The optimal design of the pores should increase the length-width ratio of the rectangular pores within the allowable range of the specification,and the number of rows or columns of the porous brick should be appropriately increased.Pore arrangement should adopt staggered arrangement,ensuring the long side of the rectangular pore is vertical to heat transfer direction pore arrangement.The porosity of the porous brick should be maximized under the conditions allowed by the specification,ensuing that the mechanical strength can meet the use requirements..