Research And Application Of Energy-saving Design For Nearly Zero Energy Residential Buildings In Zhengzhou

With the rapid development of the global economy,the energy crisis and environmental problems have followed.Among them,building energy consumption accounts for a large proportion of energy consumption.In order to solve the energy problem,Developed countries such as Europe and the United States are vigorously promoting the development of building energy efficiency standards and technical strategies.Since the 1980s,the"three-step"strategy for building energy efficiency in China has basically achieved results.At present,our country are moving towards a higher goal——"nearly zero energy buildings".The national standard of nearly zero energy buildings has been promulgated and implemented,but the building energy efficiency design should follow the principle of adapting to local conditions,and the energy-saving design research for nearly zero energy buildings in Zhengzhou is still in its infancy.Based on the above reasons,this paper uses the method of energy consumption simulation to analyze the influencing factors of energy consumption in residential buildings in Zhengzhou.The author designs orthogonal experiments tostudy the primary and secondary relationships between the factors and forms the optimal combination.Researching the first nearly zero energy building in Zhengzhou and verifying its feasibility are for sake of grasping the technical points of energy-saving construction and the use of renewable energy.First of all,the author investigates the literature related to advanced domestic and foreign nearly zero energy technologies.Based on the definition of nearly zero energy buildings,it is concluded that the nearly zero energy buildings should be realized from two aspects:"broaden resource"and"save expense",that is to effectively reduce building energy consumption while making full use of renewable energy.This article analyzes and researches passive and active energy-saving design measures for nearly zero energy buildings,and integrates renewable energy utilization in Zhengzhou.Secondly,by investigating the types of residential buildings in Zhengzhou and combining relevant specifications,setting indoor and outdoor parameters to establish a typical residential building model in Zhengzhou.The author uses Design Builder energy consumption simulation software to analyze the influence of factors such as heat transfer coefficients of exterior walls and roofs,building orientation,comprehensive heat transfer coefficients of exterior windows,solar heat gain coefficient,and north-south window-to-wall ratio on annual heating demand,annual cooling demand and building energy consumption.Then,selectthe above factors that affect building energy consumption,use Minitab software to design L₂₅（5⁶）orthogonal test,and simulate and calculate the building energy consumption under 25 different combinations of factor levels.The primary and secondary relationships that affect the total energy consumption of the building using the range analysis method are:heat transfer coefficient of the external wall>heat transfer coefficient of the external window>north window to wall ratio>south window to wall ratio>north to window solar heat gain coefficient>south to window solar heat gain coefficient,and the lowest factor level combination that selects the total energy consumption of the building is selected.Finally,in combination with the first nearly zero energy demonstration building in Zhengzhou,this paper analyzes the building’s energy-saving construction measures and renewable energy utilization,and through modeling and analysis,calculates that the annual cooling demand is 15.59（k Wh/（m²·a））,the annual heating demand is 9.14（k Wh/（m²·a））,the building energy consumption value is 35（k Wh/（m²·a））,and utilization rate of renewable energy is 53%,which all meet the energy efficiency index requirements of the nearly zero energy residential buildings in"technical standard for nearly zero energy buildings"GB/T 51350-2019.