Methodology for the calculation of response factors through experimental tests and validation with simulation

One of the most simple and intuitive methods employed to characterise a building solution in transient regime is based on the use of response factors. Its acquisition by calculation is an appropriate approach when the thermo-physical properties of the materials are known. However, in a great number of building products these data are not available and thus large errors in the calculation may be incurred, which cannot be quantified.In this work, a dynamic testing method is presented inside a guarded hot-box unit, where the response factors of a wall can be obtained without requiring the corresponding material properties.This method has been validated by means of a finite volumes simulation code for a wall which thermal characteristics are perfectly defined. Although the errors committed when adding the response factors and comparing them with the transmittance values are higher in the experiment than in the numerical analysis, there is a good agreement between the heat flows obtained experimentally and with the simulation.     

缀铝箔聚苯板空心墙体保温性能的测试与分析

以聚苯板夹芯墙体为对照,对缀铝箔聚苯板空心墙体保温性能进行了测试。测试结果表明,聚苯板夹芯墙体和缀铝箔聚苯板空心墙体的传热系数分别为0.43W/(m·2K)和0.31W/(m·2K),均具有较好的保温性能;2种墙体的传热系数与理论计算的相比分别增大了43.3%和24.0%;理论计算和实际测试的聚苯板夹芯墙体的传热系数比缀铝箔聚苯板空心墙体分别提高20.0%和38.7%,表明缀铝箔聚苯板空心墙体的热工性能更好,受环境因素的影响较小。     

一种新型墙体热工测试系统的研究

通过对现有建筑维护结构的传热系数现场检测技术的分析与研究,提出了一种新型的墙体传热系数现场检测系统.采用此新型系统对不同厚度的XPS保温板和墙体进行现场测试,将测试结果与理论值进行对比,检验了此系统的可行性以及准确性.并且在检测XPS保温板传热系数时进行了温度修正,提高测试系统的精确度.     

Experimental and numerical investigation of a hollow brick filled with perlite insulation

The present study is focused on the investigation of the effective thermal properties of a modern vertically perforated masonry unit filled with perlite insulation. Based on measurements and numerical calculations, the thermal performance of the new hollow brick was determined. The authors suggest to use the following parameters for this building material: equivalent heat capacity equal to 855.1 J/kg K, equivalent heat conductivity equal to 0.09 W/mK and equivalent density equal to 653.15 kg/m³. The dependence of the equivalent thermal resistance of the whole wall made of this brick and mortar, is shown for different mortar joint thicknesses. All results, presented in this paper, can be used in energy balance calculations for buildings made of masonry unit.     

建筑外墙热工性能和节能设计分析

本文介绍福建省常用外墙材料的隔热保温构造形式和热工性能试验分析结果,并对我省建筑外墙的墙体节能提出看法和建议。     

Thermal dynamic transfer properties of the opaque envelope: Analytical and numerical tools for the assessment of the response to summer outdoor conditions

The reliable estimation of buildings energy needs for cooling is a crucial issue in the implementation of the EPB Directive 2010/31/EU (formerly 2002/91/EC), especially in central and southern Europe climates. On this purpose one of the main topics is to predict the behavior of the opaque envelope subjected to variable boundary conditions. The EN ISO 13786:2007 technical standard assumes sinusoidal boundary conditions and introduces dynamic thermal characteristics.The aim of this paper is to assess the deviation arising by the use of different approaches for the calculation of the dynamic thermal characteristics of an opaque envelope element under periodic non sinusoidal boundary conditions. The EN ISO 13786 procedure has been firstly applied by decomposing the external forcing temperature by means of the Fast Fourier Transform (FFT) analysis. A comparison with different approaches, such as Finite Difference Methods (FDM) and Transfer Function Methods (TFM), has been carried out.The predictions of the EN ISO 13786 with a sinusoidal forcing temperature (i.e., standard approach) have also been assessed, comparing the results to the ones obtained through the FFT analysis. Furthermore, corrections to the periodic thermal transmittance and to the time shift have been proposed, in order to improve the explicative worth of those parameters.     

大空间建筑室内热环境CFD模拟中壁温及室温的求解

应用PHOENICS软件模拟某体育馆的室内热环境,将壁温作为模拟的第一类边界条件。建立了室内表面对流辐射耦合换热方程,着重讨论了采用表面换热分析法求解表面传热系数以求解壁温的方法。因壁温计算和室温计算互相耦合,采用迭代计算的方法求解壁温和室温。模拟计算结果与实测结果基本吻合。