Influence Of Frequency Weather And Sunshine Rate On The Dynamic Heat Transfer Characteristics Of Building Envelopes

With the development of economy and technology in China,building energy consumption is increasing.my country’s building energy consumption accounts for nearly 30% of the total energy consumption in society.Especially the HVAC system has an increasing demand for energy,and excessive demand leads to The resources of the entire society tend to decrease year by year,and reducing building energy consumption has become the focus of attention from all walks of life.Studying the dynamic effects of outdoor weather changes on the analysis of indoor temperature and heat transfer and improving building energy efficiency are of great significance.Existing studies have mainly focused on the effects of outdoor temperature,heat preservation methods,and heat transfer parameters of the envelope.In fact,the changing characteristics of cloudy and sunny weather will also cause the envelope structure to absorb solar radiation differently,which will have a greater impact on the heat transfer and heating energy consumption of the envelope structure.To this end,this paper takes the winter climate conditions in Shanghai as the background and the solar altitude change rule on January 15(the coldest month)as the condition to study the dynamic changes of the weather frequency and sunshine rate on the outer wall temperature of the southward room And heat transfer.The convective heat transfer coefficient and the position of the insulation layer have an important influence on the surface temperature of the wall and the heat dissipated into the atmosphere through convection.Therefore,this paper uses numerical simulation calculation methods to focus on the position of the insulation layer,the convective heat transfer coefficient,and the weather.The dynamic analysis of the solar energy absorption by the south outer wall is carried out on the changing frequency and sunshine rate,and the dynamic heat transfer process of the floor slab and the inner partition wall connected with the south outer wall is studied.The research results show that,regardless of internal or external thermal insulation,although the frequency of changes in weather has a significant impact on the heat transfer and internal and external surface temperature of each part of the enclosure structure,it has little effect on the time average effect and can be ignored.The indoor heat absorption of partition walls and floor slabs is less than that of internal thermal insulation under external thermal insulation conditions,but the absorption of indoor heat on the inner surface of external walls is greater than that of internal thermal insulation under external thermal insulation conditions.Whether it is internal or external thermal insulation,when the sunshine rate is 2.5 times,the heat transfer of the wall is not 2.5 times the relationship.Comparing the solar radiation rate of29% and the solar radiation rate of 71%,the heat transfer can be obtained when the number of study days is the same.The heat dissipation of indoor air to each part of the wall under external heat preservation conditions is less than the heat dissipation of indoor air to each part of the wall under internal heat preservation conditions.That is,no matter how the frequency of the weather changes,the average sunshine rate can be used to characterize the solar energy absorption of the solid wall throughout the winter,and the total solar energy absorbed by the wall has a nonlinear relationship with the sunshine rate.