Study Of Natural Ventilation Effect And Energy Consumption Simulation For High-rise Residential In Xi'an

With the rapid urbanization and economic growth in China,high-rise residential buildings have become the main form of urban housing.Natural ventilation,as a "zero energy consumption" method of ventilation,plays an important role in improving indoor air quality and indoor space comfort,which has been widely loved.However,the wind and thermal environment outside the high-rise residential buildings are more complicated,thus the households are more inclined to use air-conditioning and other means to create a stable and comfortable indoor living environment.Therefore,creating a healthy,environmentally friendly living space that people are willing to accept,using natural ventilation to reduce building energy consumption and improve indoor air quality has become the focus of architects nowadays.Firstly,The open problems of indoor natural ventilation for high-rise buildings in Xi'an and the major factors influencing the effects of natural ventilation were obtained by investigating the current status of high-rise residential buildings and making questionnaire to probe the effects of natural ventilation presently,combining with the unique regional climate characteristics of Xi'an.According to the survey results,this article adopted the average indoor wind speed and the mean age of air as evaluation criterion to research the effects of indoor natural ventilation for high-rise residential buildings under different building densities and different opening area of windows by employing the FLUENT numerical simulation method.And the accuracy of simulation results has been verified with the help of on-site measurement.Simulated and experimental results show that the effectsof indoor natural ventilation for high-rise residential buildings does not deteriorate as the building density increases,while the effects of indoor ventilation is the best when the building density is 15%;moreover,the effects of natural ventilation in the master bedroom and the opening area of single side windows are positively correlated,and the ventilation in the master bedroom is the least affected by that when the building density is 15%.All the conclusions show that the best building density can guarantee the best effect of natural ventilation under the premise of saving land resources.Finally,the De ST-Vent Plus software has been employed to simulate and analyze the influence of inter-building effect and the speed of outdoor flow on energy consumption for residential building respectively.IBE index has been used to quantify the accuracy of energy consumption estimation.It is indicated that buildings in Xi'an has good potential of natural ventilation,and the monthly energy saving rate can reach up to 45.6%.The inter-building effect has a significant impact on the energy consumption of residential buildings,and it has the greatest impact in summer;the energy consumption of high-rise residential buildings is positively correlated with the building density,while the accuracy of building energy consumption estimation is reduced,which error rate can up to 75.5%;the energy consumption of residential buildings is negatively correlated with the outdoor wind speed.However,the IBE index value of building energy consumption is quite large for the annual average wind speed is 2 m/s in Xi'an.Thus,the accuracy of building energy consumption estimates will be low without taking the inter-building effects into account.All the research results above may provide reference and guidance for planning and design of residential district and estimation of building energy consumption.