Research On Air Tightness And Fresh Air System Of Ultra-low Energy Consumption Buildings In Cold Areas Of Henan Province

The development of passive ultra-low-energy buildings has become a global trend in the field of building energy efficiency,and most countries will be forced to promote by decree.China has accumulated a wealth of technical experience in passive ultra-low energy-consuming buildings.In this paper,the five-party Science and Technology Museum,a demonstration project of ultra-low energy-consuming buildings in cold regions of Henan Province,is taken as the research object,the air tightness of one of the key passive technologies is simulated and analyzed,and the outdoor Air System of passive ultra-low energy consumption building in cold area of Henan Province is studied and some suggestions are given.Firstly,the indoor environment is simulated and calculated by Energy Plus building Energy simulation software,and the natural room temperature and building Energy consumption under different air-tightness are analyzed,and the recommended air-tightness index in cold area of Henan Province is obtained.Secondly,on the premise of good air-tightness of the building,the changing trend of building energy consumption with fresh air demand under natural ventilation,mechanical ventilation and mechanical ventilation with heat recovery is simulated and analyzed,and the best ventilation strategy is proposed.Then,through the field measurement and simulation analysis of the outdoor air heat recovery system of Fivewin Science and Technology Museum,the influence of the system form,air volume and operation strategy on the energy consumption of the system is obtained,the heat recovery form and operation strategy suitable for cold climate region of Henan Province are put forward.Finally,the operating time analysis and investment recovery period calculation of the new air heat recovery system of Fivewin Science and Technology Museum are carried out,and the optimization suggestions of the existing heat recovery system are given.The results show that the air-tightness index of ultra-low energy consumption buildings in cold area of Henan Province should be 0.2 times h^-1?N₅₀?0.6times h^-1.For building ventilation strategy,when the fresh air demand is less than 900m³/h,the window-opening ventilation is preferred;when the fresh air demand is 900m³/h?1500m³/h,the mechanical ventilation without heat recovery is preferred;when the fresh air demand is more than1500m³/h,mechanical Ventilation with heat recovery is preferred.The application potential of the outdoor air heat recovery system in the cold area of Henan Province was evaluated.The results showed that the energy-saving effect of the outdoor air heat recovery system was significant from November to March.The highest energy-saving rate was 55.25%,followed by June,July and August,the energy saving rates were 23.64%,32.82%and 26.83%respectively.Based on the analysis of the minimum economic enthalpy difference,the number of days suitable for fresh air heat recovery is 243 days in cold area of Henan Province.