Study On Influence Of Hole Configuration On Thermal Performance Of Hollow Block Based On Dynamic Condition

Beacause of the advantages of energy saving, land saving, waste recycling, eco-friendly, high labor productivity and sustainable development, hollow block has been more and more widely used in building external walls. Since changing internal structures have different influence on thermal performance of hollow blocks, study on the influence of the change of hole configuration on thermal performance becomes an important work. This paper will study the influence of the change of hole configuration on thermal performance, and carry out a kind of hollow block which can achieve the beast thermal performance, analysing building energy saving effect of this hollow block.First of all, this research establishes the hollow block model of numerical calculation, which is verified by experiment. Secondly, under the condition of constant hollow ratio(the consumption of skeleton material is constant) and overall dimension, doing simulation research on thermal performance of hollow blocks with different internal structures to get the structure which can achieve the best thermal performance. Finally, using building energy simulation software EnergyPlus to study the heating energy consumption of the hollow block in a building.According to the research, it is found that under the same hollow ratio, increasing the number of holes perpendicular to heat flux can make time lag and decrement factor increased to 4h and 13.89. It can also decrease the heat flux on internal surface to 5791 KJ/m2, but when the number of holes perpendicular to heat flux is 5, this value can be improved little. Increasing the number of holes perpendicular to heat flux can also decrease the convective and radiation heat on lateral hole wall. Increasing the number of holes paralell to heat flux has no influence on time lag, but decrement factor is decreased to 11.36. Increasing the number of holes can strengthen the effect of thermal bridge, and lead the heat flux on internal surface increased by 34.1%. If it is needed to set holes paralell to heat flux, holes are better staggered to weaken the thermal bridge and improve energy saving effect. Filling different insulation material into holes can increase decrement factor and heat flux on internal surface up to 14.29 and 22%, respectively. However, there is no influence on time lag. When the thermal conductivity and thermal capacity is decreased, time lag can be increased from 4h to 6h, and decrement factor is increased from 13.89 to 45.93. In addition, the heat flux on internal surface can be decreased by 84.1%. In this paper, the hollow block which is obtained by theoretical research can decrease 27.64 GJ heating energy in heating season. Compared with the original block,the heating energy is decreased by 7.2%.The results of this study will play a guiding role in the design and production of hollow block, and contribute to the energy saving in buildings.