基于生命周期成本的墙体外保温层最佳经济厚度确定

Determination of the Optimum Thickness of External Insulation for Walls Based on Life Cycle Costing

墙体外保温是应用最为广泛的节能方法之一,保温材料种类繁多,保温层最佳经济厚度的确定受诸多因素影响。从保温材料的全生命周期出发,结合生命周期成本法,建立能耗数值计算模型,从保温材料的热工性能和经济性能两个方面进行评价,得到8种保温材料应用于成都地区典型基层墙体时对应的总成本、节能率、投资回收期及保温层最佳经济厚度。经数据拟合,得到的最佳经济厚度δ_(i)与导热系数λ和单价C_(i)的关系式为:δ_(i)=-2.63+2.1×10^(6)(λ/C_(i))-1.74×10^(10)(λ/C_(i))~2+5.38×10^(13)(λ/C_(i))^(3),最佳经济厚度对应的最低总成本C_(Ti)与导热系数和单价的关系式为C_(Ti)=113.24λC_(i)+6866.78。所得公式简单实用,可为成都地区建筑节能设计提供参考。

The optimum thickness of external insulation,which is widely used in walls for energy conservation with a wide variety of materials,is determined by various factors.On the basis of the life cycle of the insulation materials,a calculation model of energy consumption was established by means of Life Cycle Costing(LCC)to evaluate such materials from the aspects of its performance in preserving heat and cutting expenses,so as to obtain the total cost,energy saving rate,pay back period and optimum thickness of eight types of insulation materials in Chengdu.With data fitting,the respective relational expressions of the optimum thicknessδ_(i)and the lowest total cost corresponding to the optimum thickness C_(T i)with both thermal conductivityλand unit price C_(i)were obtained,which areδ_(i)=-2.63+2.1×10^(6)(λ/C_(i))-1.74×10^(10)(λ/C_(i))2+5.38×10^(13)(λ/C_(i))_(3)and C_(T i)=113.24λC_(i)+6866.78.The formulae,which are simple and practical,can offer ideas for the energy-saving design of buildings in Chengdu.