| The Yangtze river region belongs to non-central heating area.The area is hot in summer and cold in winter,which results in a bad indoor thermal and humidity environment.Many existing residential buildings have poor air tightness.In the past,there was less heating,the problems of air tightness was not prominent.With the improvement of the thermal performance of the envelope and the comfort requirements of the residents,more and more residential buildings have begun to adopt different heating methods.Air tightness of buildings have became an important factors that influence the energy consumption and indoor thermal environment.Therefore,the problems caused by the airtightness in this area are worthy attention.Fistly,the thesis clarifies the window by opening types and frame types that are common in typical cities of Yangtze River region by literature review and field surveys.Through the tracer gas method and the blower door pressure method,the airtightness of the residential buildings of different ages,window forms and structures in typical cities of the region are measured.Preliminary conclusions are obtained based on the test results.The results show that the window of the old buildings are severely abrasion and weathered,which result in a poorer level of airtightness of the building;the windows of new buildings have a higher level of airtightness when tested at the lab,but it is quite different with the actual airtightness level due to the level of worker installation and the out-of-wall holes are not easy to find during the decoration.Finally,some sugestions are put forward for the above problesms.Secondly,two common types of windows in the Yangtze River region are tested under 120 conditons that based on the theoretical analysis of the air permeability characteristics.The numerical are fitted according to the experimental results to obtain the permeability characteristics parameters under different conditions.The comparison shows that the fitted data are different from the values in the current code,because the values given in the code are based on the empirical values summarized by a large number of projects in the 1990 s and the original data are from the cold regions.But the wind penetration under that conditions is quite different from the energy-saving windows usually used in the Yangtze River regin now.Finally,relative error analysis are calculated between fitted values and 0.67 in the code.Thirdly,using typical residential buildings as a benchmark model,EnergyPlus simulations are used to simulate the heating and air conditioning energy consumption under different air tightness levels,and the relationship between air tightness and the insulation performance of the envelope is explored.Besides,the impact of airconditioning hours,energy consumption of heating and air-conditioning under different air-tightness levels in typical cities in each sub-climate zone were analyzed.In addition,in order to investigate the effect of airtightness on the indoor thermal environment,CFD was used to simulate the effect of air penetration on the indoor temperature field and air speed field.The research results provide a certain reference for further reducing the energy consumption of heating and air conditioning of residential buildings in the Yangtze River region,which can improve the thermal comfort of indoor residents and optimize the indoor thermal environment.Finally,based on the life cycle of the building,taking the annual energy consumption as the analysis object,the life cycle cost analysis is used to analyze the total cost of windows with different airtightness levels.Draws the most economical combination.Next,according to the parameter settings of the benchmark buildings in the energy-saving design standards of different cities in the Yangtze river region,the energy-saving rate after air-tightness improvement is obtained through simulation,and the energy-saving potential of the air-tightness level improvement for typical cities in the future is predicted and evaluated.The thesis looks forward to research on the air-tightness and air-window permeability of buildings in the Yangtze River region by simulation and experimental,which will provide some research basis for improving the energy conservation rate and improving the indoor thermal environment. |
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