Study On The Dynamic Heat Load Of Civil Buildings In Northern Region

At present,the central heating system is the main form of heating in urban areas in northern China.Although the growth trend of central heating energy consumption has slowed down in recent years,it is still the main part of China's building energy consumption.The heating effect of the existing central heating system is not ideal.The heat supply of the heat source does not match the heat demand of the heating building.The phenomenon of excessive heating and uneven heating and heating is widespread,which not only increases the heating energy consumption,but also affects heating quality.The heat supply to the heating system is regulated according to the building heat load.Therefore,it is necessary to accurately calculate the building heat load.This paper proposes a heat load calculation method that is convenient for engineering applications-indoor dynamic heat load method.This method focuses on the influence of the building's own characteristics and outdoor weather conditions on the heat load,It introduces the equivalent value of outdoor air comprehensive temperature,instead of the interaction of outdoor air temperature and solar radiation,establishing a theoretical model and obtaining the changing rule of the dynamic indoor heat load.The dynamic heat load changes regularly so that the heat load can be accurately predicted.This paper focuses on the different influences of the building's own characteristics and outdoor weather conditions on the load.Outdoor weather conditions are complex and changeable.Air Temperature,humidity,wind speed,atmospheric transparency,cloud content,solar radiation intensity and so on all change at any time.Moreover,various factors have different degrees of relationship,some factors indirectly affect the heat load through other factors.Through the research,we find out the relationship between each factor,and express the degree of their influence directly by the formula.For the influence of outdoor air temperature and solar radiation on indoor environment,when calculating the hourly heat load through the external wall or roof,the combined outdoor air temperature is chosen as the calculated outdoor temperature,in which the influence of night radiation was also taken into account.When the heat load is calculated by hour by hour through the door and window,the heat loss formed by the heat transfer of temperature difference and the heat gain from the solar radiation directly through the door and window are calculated respectively.Taking the public buildings in Changchun as a case.This paper applies the indoor dynamic heat load calculation method studied in this paper to obtain the hourly heat load and dynamic curve of the building.Finally,it compares with the traditional heat load calculation method and analyzes the two methods.The data can be obtained by the indoor dynamic heat load calculation method to better meet the building needs.The study of indoor dynamic heat load provides a reliable basis for the design and operation adjustment of the central heating system,thus achieving the purpose of“on-demand heating”.This can not only improve the current heating technology level,improve the heating quality,but also avoid energy waste,save energy consumption,reduce emissions of pollutants,improve the ecological crisis.