Study On The Thermal Performance Of Envelope And Intelligent Control System Of Artifical Cold Source In Building

The function of building is to yield an agreeable indoor micro-climate that makes people feel comfortable. However ,in the modern society ,there is a conflict between the increasingly went short of energy and the highly thermal comfort. Thus , finding a balance point between the low energy and high thermal comfort in building is a hot topic .In the thesis , composite wall ,intelligent envelope ,artifical cold source control system in HV&AC etc and such the elements used in the modern ecotypic architecture are selected as the objects to make research, in which the cut-in points are the factors that influence the building thermal load and the human thermal comfort.The main contents are summarized as follows:(1) The transient thermal characteristic and the sensitive factors of composite wall are analyzed with method of FDR;With the finite element method ,the affected zone of rectangle thermal bridge in steady state is studied; furthermore ,the impact of mean radiant temperature on human thermal comfort and the energy consumption in building are analyzed with the thermal comfort model developed by the Fanger . Under the typical meteorologic condition in summer and winter ,the temperature of inner surface of composite wall is simulated .(2)The thermal performance of solar wall in different mode,such as the heat collection and pre-heating in winter ,heat insulation in summer, ventilation in spring and autumn are analyzed respectively by coupling the solid heat conduct and hydrokinetics with CFD technology ,moreover,the sensitive factors such as material ,height, thickness of air gap, vent area of trombe wall are investigated; the prediction models of thermal performance about trombe wall are given with the methods of artifical neural net and regression equations .(3)With the detailed analysis of the thermal process in glass double facade ,the system governing equations are solved by combing the CFD model with the optical model and transparent system model .The parametric study is carried out on the sensitive factors,such as the position of louver, louver salt angle, width of facade, area of vent ,solar irradiation, outdoor temperature, wind orientation .During the research , the optimal dimension is presented . With the CFD simulation results ,the dimensionless model founded on theπtheorem and the regression equations about convective heat transfer coefficients based on gray model are put forward. Furthermore, the thermal performance of double skin facade that operates in the modes of heat preservation in winter and air exchange and ventilation in spring and autumn are also discussed.(4)With the simulation results and the principle of decoupling and human thermal comfort , the compound-control strategy and the fuzzy self-adaption arithmetic are presented to design the artifical cold source control system ,in which the S7-300 PLC is used as the center controller .