Numerical Simulation For Complicated Heat Transfer Performance Of Hollow Brick With Different Height Sizes

This article uses three-dimensional self-programming code to make anumerical simulation of complicated heat transfer including conduction,convection and radiation in hollow brick walls on four hollow brick height of240×115×90,240×115×115,240×115×140and240×115×165mm,which havea total of200kinds of configuration (each height50kinds). The aim is atrevealing the influence of hollow brick height on the equivalent thermalconductivity of building walls when the hole number, arrangement, length andwidth are at the same. Meanwhile, two hollow brick height of240×115×115,240×115×140mm are selected to analyze the influence of theoutside convection heat-transfer coefficient on the equivalent thermalconductivity of hollow bricks. The simulation results give certain guidance forthe structure selection of hollow bricks and the building energy efficiency. Thenumerical simulation shows that:1. The rule of the equivalent thermal conductivity of hollow bricks whichhave the same height sizes with the hole number changing is basically at thesame. Given the hole number in width, the equivalent thermal conductivity of hollow bricks decreases and then increases with increasing hole number inlength.2. With the increasing of the height, the equivalent thermal conductivity ofhollow bricks which have different height sizes has a downward trend, exceptfrom individual brick type. Given the hole number in width, drop ratio increasesand then decreases with increasing hole number in length, in which the biggestdrop is of6.1%.3. The best constructions of hollow bricks which have the different heightsizes are all L05W4H1.4. For selected two hollow brick height of240×115×115,240×115×140mm, the outside convective heat exchange coefficient has nearly no effect onthe equivalent thermal conductivity, in which the biggest change rate is less than2.0%.