Simulation And Optimization Analysis Of Typical Thermal Bridges In Passive Houses

Passive housing,as a form of the current low energy consumption buildings,refers to the building which can maintain a comfortable indoor thermal environment without active heating and air conditioning system.Building thermal bridge exists in traditional residential buildings and passive housings,which has great influence on the building energy consumption and the quality of the indoor thermal environment.To solve the thermal bridge thermal dissipation and put forward measures to restrain or eliminate thermal bridge are vital for the popularization and application of passive housing.Good palisade structure and precision construction technology are adopted in passive housing.In order to analyze quantitatively the influence circle of thermal bridge in the passive house compared with the traditional residential in heating season,thermal bridge site steady two-dimensional simulation were conducted for both passive energy-saving and traditional residential using the FLUENT software.The results show that,in the passive energy saving buildings,thermal bridge was inhibited well,and influence scope was greatly reduced.Then,energy consumption simulation was conducted for a typical passive energy saving building in"Zaishuiyifang"residential district in Qinghuangdao City using DeST energy consumption simulation software.In the simulation,with the same conditions of the construction site,thermal perturbation,air conditioning and room function,the parameters of the structure of the model were set according to the passive house standard,75%,65%and 50%energy-saving residential housing standard,respectively.As indicated by the results,it is found that in a heating season,energy can be saved efficiently in passive houses compared to 75%,65%and 50%in energy efficient residential energy-saving residential.The relatively energy saved are 10.98,20.69 and55.31kWh/(m~2·a),respectively.Moreover,energy consumption index were increased as58%,72.3%and 87.4%respectively.It is obvious that in heating season,passive house is more economical than the 75%,65%and 50%energy efficient residential energy-saving residential.Finally,the energy consumption of building thermal bridge was computed with Monte Carlo simulations in the study.The results show that the total heat consumption of thermal bridge in passive energy saving residential was reduced by 42.2%,53.7%and66.9%,compared with 75%,65%and 50%energy saving buildings,repectively.It benefits from the improved palisade structure with insulation material,construction technology,etc,in passive house.It is also calculated that heat due to thermal bridge accounted for 22.1%,27.1%,16.3%and 10.2%of the total heat,in passive house,75%,65%and 50%energy-saving residential respectively.Besides that,energy saving rate is about 91%in passive energy-saving residential.It is worth noting that both the total energy consumption and energy consumption due to thermal bridge were reduced,while the proportion of energy consumption resulted from thermal bridge increased.Therefore,it is particularly important to put forward sepecific measure to restrain the thermal bridge,which definitely can promote the application of passive energy-saving residential and provide a powerful basis for structure optimization.