建筑构件热阻计算方法

针对空心砌块平均热阻理论计算方法的简单近似性,分析了其计算结果的不确定性,提出用CFD数值模拟、采用有限体积法的计算方法分析建筑构件的热工性能.并分别运用热流计法与热箱法对某内插保温层混凝土空心砌块进行热阻测试,以检验理论计算方法与数值模拟计算方法的准确性.通过理论计算、数值模拟及试验验证分析得到:采用理论计算方法分析建筑构件热工性能具有不确定性,所得结果与热流计法和热箱法的试验结果误差分别为36.6％和33.8％；采用CFD数值模拟方法计算结果误差分别为0.3％和2.4％,表明该方法对建筑构件热工性能的计算不仅能够满足精度要求,还具有应用范围广、结果直观等优点.

Calculation methods on thermal resistance of building components

Considering the simple approximation of a theoretical calculation method on the average thermal resistance of hollow block,the uncertainty of the results calculated by this method was analyzed.A novel calculation method based on CFD(computational fluid dynamics) numerical simulation with finite volume method is proposed to evaluate the thermal characteristics of building components.The accuracy comparison between the CFD numerical method and the theoretical method was conducted by using heat flow meter method and hotbox method to test the thermal resistance of a concrete hollow block with inserting thermal insulation layer.Through the analysis of theoretical method,CFD numerical method and experimental validation,it is concluded that the thermal characteristics of building components from theoretical calculation method quoted in the paper are of uncertainty,the result errors of which are 36.6% and 33.8% in respect to the results of heat flow meter method and hotbox method.The result errors of CFD numerical simulation method are 0.3% and 2.4% respectively;the accuracy of the numerical simulation method is satisfactory,meanwhile,the method has advantages of wide application fields and visualized result presentation.