The Mining Of Overall Thermal Performance Of Envelope Based On Reverse Analysis Of Building Thermal Process

Overall thermal performance of building envelope is the key influence factor of building energy efficiency,whose evaluation is an important link of energy efficiency retrofit.In view of the limitations of thermal performance detection method--lack of entirety and accuracy,this paper presents a novel method for estimating overall thermal performance of building envelope based on actual heating operation data.Through achieving reverse resolution of building thermal processes with the different morphological characteristics of data,the building envelope heat loss component is easy to decompose from building heat consumption,which is used to characterize thermal performance of building envelope.First of all,this paper describes the building thermal process in detail,and based on which opens the idea of building thermal process reverse analysis.From the two aspects of mechanism and data characteristics,the feasibility of reverse analysis is introduced,and this paper describes the method for the two kinds of system of building thermal processes: steady and dynamic process,puts forward two reverse analytic ideas--based on morphological characteristics of dynamic data and based on the morphological characteristics of steady data.Secondly,using the extraction method with steady data morphological features mentioned in this article,the overall thermal performance of building envelope is mined,the ability to extract time series of envelope heat loss is validated with software simulation data,and the average absolute relative error--MAPE remains at 5.3%.The results of the practical case analysis show that the heat loss coefficient of building envelope is compared with the theoretical design value,and the error is 5.9%.To a certain extent,the accuracy and applicability of the method are explained.Finally,as an extension of the engineering application,two groups of real buildings are analyzed,one is a single building,another one is a group of buildings which take the heat station as a unit,the level of overall thermal performance of the building envelope is analyzed,and with the current standard of energy saving under the comparison of theoretical value,whose energy-saving potential are nearly 20%.