The Calculation Approach Of Heat Transfer Of Underground Region And Thermal Bridges For Building Energy Simulation

Building simulation technology is an effective means to research how building envelope influence building energy consumption. With the insulation of building envelope better and better, the heat transfer of underground region and thermal bridges is more and more important. The heat transfer process of them is apparently two dimensional or three dimensional, and can't be simulated in building simulation program. Therefore, it is very important to research new calculated approach. Supposing the thermal characteristic of underground region not varies with temperature, the heat transfer process of underground region is divided into three ones depend on influence factors. The characters of the heat transfer process influenced by difference factors are studied. Based the characters, different approaches are presented to calculate the heat transfer processes. The results can be obtained quickly and is very easy to be implemented into building energy simulation program.The influence factors of thermal bridges are divided into two types: external factors and inner factors. Supposing the thermal characteristic of area of thermal bridges not vary with temperature, the characters of the heat transfer process influenced by external factors and inner factors are studied separately. Based the characters, the equivalence slab for external factor and the equivalence slab for inner factor are presented. The equivalence slabs are obtained quickly and is very easy to be implemented into building energy simulation program.Based on the new calculation approaches, how to establish dynamic heat transfer database of underground region and thermal bridge is studied and the detailed practice is shown.