Study On The Building Integrated Thermal Inertia And Heating Load Characteristics Under Different Wind Speeds

Energy-saving in buildings has become one of the major issues in the energy field.Making use of the building integrated thermal inertia effectively is an important way to realize the energy-saving in buildings.By the researches and utilization of the integrated thermal inertia,the heating/cooling load designing of HVAC system will be more scientific,the system operation and regulation will be more reasonable.Finally,it will achieve the purpose of energy saving,while improving the indoor thermal comfort.This paper mainly researches on the integrated thermal inertia of a model building through the theoretical and experimental study.The effect of the wind speed on the temperature response is evaluated;the mathematical function model of wind speed and corresponding integrated thermal inertia is formulated;the comparison and analysis of different heating controlling strategies are made.Firstly,this study is based on the understanding of the unsteady heat transfer theory and building thermal characteristic indexes.Combined with the influence factors of building integrated thermal inertia(the outdoor meteorological condition,heat storage body forms,the indoor heat source),a method of model experiment is put forward to study the building integrated thermal inertia.Then the similarity relation of model building is calculated according to the similarity theory.The model experiment is carried out in several operating conditions,when the geometric similarity ratio of building model is 0.5.The time delay,the ratio of temperature attenuation,the storage heat flux density and instantaneous temperature are selected to be the representative parameters,in order to study the effects of wind speed on building integrated thermal inertia.Then according to the relationship between the wind speeds and the characteristic parameters,the linear regression functions are carried out.The function gradients and correction coefficients are used to describe the influence of wind speed and initial conditions.Finally,the indoor temperature characteristics under three kinds of heating regulation mode(constant,peak load shifting,phase jumping)are compared.The scheme of hourly heating regulation is put forward after optimization.The research results show that: the building integrated thermal inertia is a comprehensive parameter related to heat storage body forms,outdoor weather,indoor heat sources and other factors.There is significant time delay and the temperature attenuation between the interior wall and the exterior wall of the building model.As the wind speed increases,the instantaneous temperature of each heat storage body and the total heat storage of the whole building model significantly reduce,but the temperature change trends have no fixed rules.Under different initial conditions,the wind speed affects the characterization parameters in different extent.Phase jumping heating can effectively save energy,while peak load shifting heating can improve the indoor thermal comfort.In summary,the conclusion in the study of the model experiment should be gradually applied to the actual constructions,and the researches on building integrated thermal inertia should be expand and deepen.