Research Of System Identification And Numerical Prediction Methods In Analyzing Heat Transfer Process Of Wall Surface

Two kinds of new research approaches, identification method and numerical method, are applied in this paper to analyze the heat transfer system of wall surface. Including 8 chapters, this paper is composed of two main parts.The first part of this paper, namely, the research of practical identification methods of the heat transfer process of wall surface, is sponsored by the State Natural Science Fund, of which the main content includes:(1)Study the mathematical description of wall surface heat transfer process, as well as its corresponding measure methods of the inputloutput variables, and experiment equipment.(2)Study the sampling, dealing and modeling identification methods of the experiment data.(3)Comparing and analyzing the models obtained by natural conditions and simulating experiments, deriding numerical relation expressions of heat transfer coefficient of ~vall surface with the air-flow related variables, modifying and inspecting the modeling and identification methods, analyzing and modifying the relation expressions of heat transfer coefficient of xvall surface with other variables.One of the new points is that the heat transfer process of wall surface and heat flux meter is viewed as one dynamic system, which is used to avoid the measure difficulties of the flow field fluctuation caused by sensors. The effects of airflo~v, radiation and the temperature difference between wall surface and surrounding air on the heat transfer coefficient of ~vall surface are studied by identification methods, in order to supply the air conditioning load calculation and the ~vall heat analysis with reasonable and accurate methods to measure and anal拁ze heat transfer coefficient of wall surface.The second part of this paper, basing on the experimental research of heat transferprocess of wall surface in the first part, tries to comprehensively apply Numerical Heat Transfer and CFD (Computed Fluid Dynamics) in the numerical calculation of indoor air flow. Its main content includes:(I)According to the shortage of conventional analyze methods, the conjugate indoor heat transfer field is systematically analyzed, and the conjugate solving method of building envelope heat conduction and indoor airflow field is founded. Moreover, we have studied the relations between the indoor field with its Ra number, the heat conduction efficiency of the materials of building envelope, and the height, width of building envelope, and so on.(2)Creating a kind of method to calculate the heat transfer coefficient of building envelope surface.The new point is that the continuity momentum and energy equations are simultaneously solved in the entire solid-fluid domain. With the help of finding the effects of the heat transfer process of building envelope on the indoor environment, solving the indoor flow field and temperature field, the heat convection coefficient of wall surface is obtained at last. This is a king of exploiting work to create a kind of new method to accurately measure and analyze the beat transfer coefficient of wall surface, to supply the rules to choose building envelope in the practical projects of future, to guarantee the correctly designing of building construction, and to build a foundation of a designing software of uilding heat field? It is quite critical to elevating the accuracy of the result of numerical simulation, accurately predicting the air conditioning load, saving the building energy consumption, and improving the level of indoor heat environment and indoor air quality.