Study On Energy Conservation And Carbon Reduction Design Strategy Of High-rise Office Building In Xi’an

In recent years,a large number of new buildings have been completed,leading to a continuous increase in the existing stock of building area.By 2020,the total existing building area has reached 66 billion m~2,among which the area of public buildings has increased from 3.8 billion m~2in 2000 to 14 billion m~2in 2020,accounting for a large proportion of the total building area.With the continuous growth of the total office building area and energy consumption in the building operation stage,it is of great significance to study the energy saving and carbon reduction of office buildings for the realization of the goal of"double carbon".At present,there is a good theoretical basis for the research on energy conservation of office buildings in cold areas in China,but there is less research on the comprehensive design strategy of energy conservation and carbon reduction for high-rise office buildings with large stock and high energy consumption from the passive and active technology combination.In order to solve the problem of high energy consumption of high-rise office buildings in Xi’an,this paper starts from the perspective of combining passive technology and active technology,takes a typical high-rise office building in Xi’an as the research object,and simulates the annual dynamic energy consumption and energy consumption of each component of the typical building by Design Builder software.To optimize the design of energy conservation and carbon reduction for typical office buildings in Xi’an area,a preliminary idea is proposed and the following researches are carried out:(1)Passive technology is adopted to optimize the design of the building envelope to reduce energy consumption during the operation of the building.The design value of energy saving and carbon reduction for the heat transfer coefficient of the outer window is determined as 1.0W/(m~2·K),the design value of energy saving and carbon reduction for the ratio of the window to wall is determined as 0.5,and the distance and length of the outer sunshade structure are 900mm and 900mm respectively.After optimizing the heat transfer coefficient of external Windows,window-wall ratio and external shading structure,the energy saving rate of building envelope is 13.2%,and the annual energy consumption of heating and cooling per unit area in the annual comprehensive energy consumption of the building is reduced from 29.3%to 26.5%.(2)On the basis of using passive technology to save energy and reduce carbon,continue to use active technology to optimize the design of building energy saving and reducing carbon.Through the installation of a centralized photovoltaic system,solar energy is used to meet part of the electricity demand of lighting and equipment in the running stage of the building,and the daily and monthly data calculation and analysis of the photovoltaic panel power production and building energy consumption added to the photovoltaic system,the photovoltaic panel achieves the best effect of energy saving and carbon reduction at 18°,at which time the total annual output of the photovoltaic system can reach 812,400 k Wh.It can meet 30.0%of the electricity consumption of the lighting and equipment system in the operation stage,and the carbon emission of the building is reduced by 24.3%compared to the initial model.(3)On the basis of improving the external enclosure structure and installing the photovoltaic system,the air source heat pump system is designed to replace the traditional heating and cooling system in order to achieve the purpose of energy saving and carbon reduction.After the application of air source heat pump,compared with the traditional system,the energy consumption of heating and cooling per unit area of the building is reduced by 48.0%,and the total annual energy consumption per unit area is72.07k Wh/(m~2·a).Compared with the benchmark building,the energy saving is 77.1%,which exceeds the energy saving standard of public buildings by 34.5%.At the same time,the carbon emission per unit building area in the operation stage of the building is reduced by 34.4%compared with the initial modelThis paper proposes an energy conservation and carbon reduction design strategy scheme that optimizes the value of heat transfer coefficient,window-wall ratio and outhanging length and distance of external sunshade structure of building envelope,coupled with photovoltaic system and air source heat pump system.This scheme provides data research support for energy conservation and carbon reduction of high-rise office buildings in cold areas by combining active and passive technologies.The overall energy consumption of high-rise office buildings exceeds the energy-saving standard of public buildings and reaches the energy-saving standard of 75%,providing a reference case for the future energy-saving and carbon reduction optimization design of high-rise office buildings in Xi’an.