On-Site Measurement of Thermal Characteristics of Building Envelopes

摘要：

Since building wall is effected by various factors in the process of construction, its actual thermal transmittance needs a measurement on a site. In this paper, System Identification Method is mainly used as the dynamic test method. The first step is to set up the dynamic thermal model about the building wall, according to the system identification theory and the test characteristic of a wall on a site. The parameters of the model are solved by the Enhanced Least Square Estimation (ELS); the structure of the model is identified by the automatic method; the ill-condition Matrix is solved by Householder transformation. So the computation method is ascertained. The second step is to design the experiment that measures the temperature on the wall and heat-flow through the wall. Through comparing and contrasting test results with theoretical value of the thermal transmittance, the accuracy error about test result of energy saving wall is in 5％. The conclusions are: the dimension of the wall is confirmed; The structure of the building walls dynamic thermal model is not fixed, The automatic identification method is used to identify the best structure.; The noise in the dynamic thermal model is white noise; the results tend to be stable with the increment of the computing data; the time needed to eliminate the effect of the heat storage to test data is different; the time to eliminate heat storage effect is reduced by increasing the cooling or heating load.

关键词： Building wall Thermal transmittance Dynamic thermal model System identification Least square method

作者: J.J. Cheng Y.F.Gong X.S.Zhang F.Yang L.Xie

作者单位: College of Urban Construction and Safety Engineering,Nanjing University of Technology,Nanjing,China College of Urban Construction and Safety Engineering,Nanjing University of Technology,Nanjing,China School of Energy and Environment,Southeast University,Nanjing,China

会议类型: 国际会议

会议名称: The 6th International Symposium on Heating,Ventilating and Air Conditioning(第六届国际暖通空调学术会议)

会议地点: 南京

会议语种:英文

页码: 2039-2046

在线出版日期: 2009-11-06（万方平台首次上网日期，不代表论文的发表时间）