建筑外墙保温厚度优化及设计参数化关系研究

Study on Optimization and Relation of Design Parametrization of Insulation Thickness for External Walls of Buildings

考虑太阳辐射得热,运用P1-P2经济模型建立全寿命周期外墙保温最优厚度数学模型,计算了哈尔滨、呼和浩特、兰州、乌鲁木齐4市6种保温系统最优厚度、最优厚度下全寿命周期总费用和净现值,明确并定性定量分析了影响最优厚度的因素。研究结果表明:保温系统最优厚度排序为岩棉>石墨模塑聚苯板>挤塑聚苯板>酚醛板≈泡沫玻璃>硬泡聚氨酯板,最优厚度下净现值排序为石墨模塑聚苯板>岩棉>挤塑聚苯板>硬泡聚氨酯板>酚醛板>泡沫玻璃,经济厚度为32. 9~111. 8mm,生命周期总费用为136. 08~235. 28元/m^2,净现值为1. 70~160. 26元/m^2。在进行建筑节能设计时,辐射吸收率、热桥面积比、生命周期年限、能源价格、能源价格增长率、单位热值费用增大能产生更高的最优厚度和净现值;而基层墙体热阻、市场折现率、保温材料价格、锅炉供热效率、输热管网效率等的增大会导致相应经济指标变小。建筑外墙不同朝向面积比对最优厚度等指标影响较小,在设计时可忽略不予考虑。

Considered the heat gain of solar radiation,the whole life cycle mathematical model for optimal thickness of exterior wall insulation was constructed with the use of the P1-P2 economic model.Also,the optimal thickness,the whole life cycle cost and the net present value under the optimal thickness of 6 insulation systems in H arbin,Hohhot,Lanzhou,and Urumqi were calculated to determine as well as qualitatively and quantitatively analyze factors affecting the optimal thickness.The results show that the optimal insulation thickness of external wall from thick to thin in sequence is RW>SEPX>XPS>PF>FG>PUR;the net present value ordered by the optimal thickness is SEPX>RW>XPS>PUR>PF>F G;and the optimal thickness is ranged from 32.9 mm to 111.8 mm;the whole life cycle cost ranged from 136.08 Yuan/nr to 235.28 Yuan/m^2,and the net present value ranged from 1.70 Yuan/nr to 160.26 Yuan/m^2.When energy conservation is designed,the increase of absorption factor of solar radiation,thermal bridge proportion,fixed number of year of the life cycle,energy prices,the growth rate of energy prices,unit heating value cost can produce optimal thickness and net present value at ahigher level.How ever,the increase of thermal resistance,market discount rate,thermal insulation material price,boiler heating and heat transfer network efficiency might result in the decline in corresponding economic indicators.Orientation of the exteral wall of buildings with a minor influence on the optimal thickness can be neglected in design.