Simulation Analysis Of The Impact Of Trees On The Residential Thermal Environment And Building Energy Consumption

Urban energy-saving measures have an important impact on the rapid development of the city.As an effective measure to reduce the cooling load of buildings,urban greening has been concerned by people.However,at present,there is a lack of research on the influence of a certain greening form on the regional thermal environment and building energy consumption,and the overall idea is applied to the research of quantitative measures for specific sites or buildings,which will make it impossible to accurately design the greening around buildings in the urban planning stage.Based on the computational fluid dynamics(CFD)software PHOENICS and building energy consumption simulation(BES)software EnergyPlus,this paper establishes the coupling idea of BES and CFD,and quantitatively analyzes the impact on trees around the building and within the community on the thermal environment and residential energy consumption.The theoretical basis and mathematical model of PHOENICS and EnergyPlus are introduced in detail,and the coupling simulation strategy for the research is established.The results show that the mathematical model can accurately predict the regional thermal environment.According to the tree crown height,leaf area index(LAI)and basic layout,different working conditions are set up by using the control variable method.The changes of microclimate environment at 10:00 and 13:00 in the daytime are compared and analyzed.The effects of tree characteristics on the thermal environment of the community are analyzed from air temperature,relative humidity and wind speed respectively Thermal comfort was evaluated and analyzed.The results show that the effects of canopy height,Lai and base layout on air temperature,relative humidity,wind speed and thermal comfort are similar in two different times.The circulation process in the coupling strategy is established,and the ratio of the temperature difference between the outer surfaces of the two buildings is less than 10% as the judgment basis of the circulation,and the numerical simulation is carried out in the period of08:00-18:00.The results showed that with the increase of canopy height and LAI,the air temperature and wind speed decreased,the relative humidity increased,and the basic layout A2 had the greatest impact on the microclimate.Taking a high-rise residential area as an example,the influence of trees on residential energy consumption is analyzed from three aspects of air permeability,cooling load index and residential energy consumption by using coupling simulation method.The results show that the energy consumption of the coupled condition is about 6.5% lower than that of the uncoupled condition.With the increase of canopy height and LAI,the air permeability and cooling load index are reduced correspondingly.In the typical weather month,the coupling condition is about 4% lower than the uncoupled condition,and the order for the influence of tree characteristics and foundation layout on residential energy consumption is: layout > crown height > LAI.This study puts forward a new idea of the study of trees on regional thermal environment,evaluates the impact on different tree characteristics and basic layout on building energy consumption,and provides theoretical support for urban landscape planning and urban energy planning.