The Research On A Simplified Model Of Building Wall Envelope And Calculation Method For Ground-coupled Envelope Heat Transfer

Advanced building and HVAC system simulation techniques provide convenient and low-cost tools for predicting energy and environment performance of building and HVAC system in their design, commissioning, operation and management, and testing and evaluating the control strategies and algorithm in energy management and control systems. A new envelope heat conduction stimulation model which is also called 3R2C thermal network model, based on circuit principle, is used to stimulate and analyze the process of dynamic heat conduction of multiplayer envelope. Firstly, wall's transfer matrix is deduced by Laplace transformation based on 3R2C thermal network model. Secondly, frequency response of transfer matrix is calculated. Thirdly, we make the frequency response of transfer matrix of stimulation model equate the theoretical frequency response of wall transient heat conduction by applying appropriate identification algorithm, from which we can obtain every polynomial's coefficient of model transfer function, then each parameter of resistance and capacitance is calculated by appropriate optimization algorithm. Finally, the envelope response factors,conduction transfer function coefficients and periodic response factors are obtained . Compared to other methods, optimized 3R2C thermal network model method is very simple and efficient, and has high accuracy and fast computation speed.The heat loss from a building foundation to the ground may, in a cold climate, account for up to one third of the transmission heat losses. The increased demand during the last two decades for more precise methods to calculate heating and cooling loads has led to many studies of the transient heat flow to(and from) the ground. This study deals with transient heat transfer of ground-coupled envelope for the slab on the ground case. The theoretical s-transfer function of ground-coupled envelope is deduced by Laplace transformation. A simple polynomial s-transfer function is estimated from the theoretical frequency response of the ground-coupled envelope by frequency domain regression method, then we can calculate transient heat conduction through the ground-coupled envelope. It provides a novel idea to calculate the transient heat transfer from ground-coupled envelope more simply and efficiently.