Research On Passive Energy-saving Design Of Green Public Buildings In Hot Summer And Cold Winter Areas Based On DeST Simulation

In recent years,with economic growth and improve people's living standards in China,building energy consumption has been stubbornly high,energy consumption of building operation accounts for about 20%in total social energy consumption in our country,harsh reality of high energy consumption,low efficiency,energy shortage has become an important factor restricting development of city and social sustainable development.Vigorously developing green buildings has become an important way of ecological civilization construction and energy saving and emission reduction in China.Under this background,based on evaluation criteria of green buildings,this paper studies passive technology around climate and regional characteristics in hot summer and cold winter areas and energy consumption characteristics of public buildings,and simulates it with DeST software,hoping that through study of this topic for building energy-saving design to provide reference value.This paper first introduces concept of green building and passive energy-saving design and current development situation in China,and points out significance of passive green building energy-saving design.It analyzes our country present green building appraisal standard insufficiency and obtains building energy conservation development direction and goal through contrast research on international and domestic main green building evaluation standard and energy part.Then combining with evaluation standard of green building in our country and germany,design requirements of passive energy saving of green building are summed up.Then it analyzes extreme climate in hot summer and cold winter,high temperature in summer,cold winter,high relative humidity in winter and summer,and relatively poor climatic conditions.At the same time,it points out that hot summer and cold winter area is an economically developed area with dense population and high performance requirements for buildings.Then by analyzing energy consumption characteristics of typical urban public buildings in hot summer and cold winter area,it points out that air conditioning energy consumption and lighting energy consumption are two most important parts of building energy consumption in hot summer and cold winter area,Accounting for more than 60%.Finally,heat transfer characteristics of buildings in hot summer and cold winter area are introduced.The design methods of thermal insulation in summer hot and cold winter regions are summarized.Then,passive technical measures are studied.Specific technical measures and methods of passive energy saving in hot summer and cold winter area are discussed.Passive technical means such as planning and design,shape design,thermal performance improvement of enclosure structure,natural ventilation,natural lighting and building shading are analyzed in detail.Main elements include:(1)Energy saving in building planning and body design.In planning and design of building,we should comprehensively consider factors such as layout,orientation,spacing and so on,and take into account reasonable organization of natural ventilation of site by reasonably controlling body shape coefficient,window/wall ratio etc.to maximize combination of planning and design with energy-saving technologies and energy use.(2)Envelop structure energy saving.Improving thermal performance of walls,roofs,doors and windows is primary factor to be considered in passive design of buildings.From aspects of energy-saving technology types,advantages and disadvantages of energy-saving materials and technical performance parameters,the author analyzes and studied wall energy-saving technology,roof energy-saving technology,outer window energy-saving technology etc.(3)Natural draft.This paper mainly puts forward two kinds of common ventilation methods:wind pressure ventilation and hot pressure ventilation.According to different ventilation forms,corresponding energy-saving strategies are put forward.(4)Natural lighting strategy.This paper mainly introduces two common natural lighting strategies,side window lighting and skylight lighting,and analyzes their advantages and disadvantages respectively.(5)Building shading.This paper introduces classification of architectural sunshade and compares its advantages and disadvantages.Design principle of building shading is summarized.Finally,through software simulation,the passive design factors such as building orientation,ratio of window to wall,ventilation,and thermal performance of external walls,exterior windows,and roofs in the envelope structure were quantitatively analyzed using DeST software.The influence of different passive design strategies on building energy consumption was obtained.The economical analysis was used to obtain the suitable thickness of the insulation layer of the model,in which the thickness of the better insulation layer for the external wall is 40mm,and the thickness of the better insulation layer for the roof is 60mm;finally,some passive design factors are orthogonally tested,which finding out the influence of different factors on building energy consumption,thus providing passive architectural design focus for architects.This paper systematically summarizes and analyzes the passive energy saving design strategy in hot summer and cold winter area,and conducts quantitative analysis on some passive design factors,which provides some ideas and directions for the passive energy-saving design of buildings in the area.