基于系统辨识的多层墙体z-传递函数计算方法

Calculating Method for the Conduction z-Transfer Functions of Multilayer Walls Based on System Identification

基于系统辨识理论提出了从墙体热传导的理论频率响应计算多层墙体z 传递函数的频域回归方法.首先,在所要关心的频率范围内计算出墙体热传导的理论频率响应;然后求解线性方程组得到墙体内外表面吸热及传热的简单的多项式s 传递函数,该多项式传递函数与双曲型s 传递函数在频率特性上是等价的;最后由多项式s 传递函数计算出墙体的z-传递函数.实例比较验证表明:该方法计算简单快捷,精度高.

Frequency domain regression (FDR) method was developed to calculate z-transfer functions of multilayer walls. This method is based on the theoretical frequency characteristics of transient heat conduction through a multiplayer wall to estimate a simple polynomial s-transfer function. The simple polynomial s-transfer function is equivalent to the hyperbolic s-transfer function of the wall in terms of frequency characteristics. First, the frequency characteristics of transient heat conduction of the wall were calculated within the frequency range concerned. Then, a set of linear equations was solved to yield a simple polynomial s-transfer function for internal, cross and external heat conduction. Finally, z-transfer functions were obtained by applying z-transforms on the time-domain response of the polynomial s-transfer function. The comparisons and validations show that this method is simple, efficient, fast and accurate.