| Guangzhou is a city located in Hot Summer and Warm Winter Zone,as hot days of summer last for a long time in the region,energy consumption of air-conditioners in residential buildings is very high.According to the statistics,air conditioning energy consumption caused by building exterior windows accounts for about 50%,therefore it‘s of great significance to conduct research on energy conservation for external windows.The external windows are not always closed in real life,people tend to open windows for ventilation when the outdoor climate conditions can meet the human thermal comfort requirements,thus the role of natural ventilation should be taken into account when studying the effect of external windows on the energy consumption of residential buildings.This article takes residential buildings in Guangzhou as the research object to study the effect of exterior window performance on building energy consumption under natural ventilation,using dynamic coupling of natural ventilation and building thermal environment model to calculate energy consumption.The main work of the dissertation is as follows:Firstly,introducing how to combine natural ventilation with building energy consumption,meanwhile using PHOENICS software to simulate the distribution of wind pressure on the open surface of the building as the input condition for the ventilation model.Secondly,the main thermal performance of the external windows(heat transfer coefficient and shading coefficient)on building energy consumption were analyzed by simulation.Meanwhile,using the binary linear regression analysis method on the air-conditioning energy consumption of the building and the heat transfer coefficient and shading coefficient of the outer window,concluded that the effect of the external window heat transfer coefficient and shading coefficient on the energy consumption of the building’s air-conditioning is reduced relative to the case without ventilation,the decrease was 5.5% and 13.7% respectively.According to the binary linear regression equation,it can be found that building shading is still one of the key factors that need to be considered in the energy-saving design of building exterior windows in the Hot Summer and Warm Winter regions of southern China.Thirdly,by analying the natural ventilation effect of residential buildings,it can be concluded that the maximum number of hours that can be cooled by natural ventilation in October accounted for 57.4% of the total number of months,and the lowest ventilation hours in July and August accounted for 1.3% and 3.1% respectively.The natural ventilation energy saving rate is between 13%~17% compared to no consideration of natural ventilation,and the natural ventilation energy saving rate is between 13%~17% when calculating the energy consumption of a building using a calculation model with a fixed ventilation and air exchange frequency of 20/h.The indoor heat carried away by ventilation is relatively less since the real natural ventilation effect is worse,therefore the natural ventilation energy saving rate is relatively low.Lastly,analyzing and comparing the effects of common glass windows on building energy consumption and economic benefits,concluded that the payback period of the ordinary insulating glass(6+12A+6),6mm blue heat absorbing glassand 6mm single layer Low-E glass is approximately 11.8 years,0.9 years,and 5.4 years respectively.The cost of energy saving is the highest when 6mm single Low-E glass is recovered,so the use of ordinary insulating glass is the least economical way,and the use of 6mm single-layer Low-E glass is the most costeffective way for residential buildings in Hot Summer and Warm Winter in Guangzhou area. |
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