Analysis And Application Of The Coupled Heat And Moisture Transfer Characteristics On Architectural Heritages

Water is the main cause of destruction on architectural heritages,which may result in diseases and accelerate the physical,chemical and biological destruction effect on the heritages,directly or indirectly.The transfer and accumulation of water in architecture materials are driven by heat transfer,so many diseases of architectural heritages,such as evaporation,condensation,salting out,freeze-thaw cycle,and mold growth,are directly or indirectly related to the heat and moisture transfer and accumulation in it.The process of heat and moisture transfer in architecture heritages will determine the effectiveness and durability of the protection strategies in most ways.So,it’s very important to predict and evaluate characteristics of it on architecture sites.Current researches have proved that,heat and moisture transfer in porous materials is an interactive and coupling process,which is known as “coupled heat and moisture transfer theory”.Based on this theory,researchers can grasp the law of hydrothermal transfer in porous materials,predicting the possible distribution of water and heat by simulation.In this study,the heat and moisture transfer simulation was used in architectural protection,to evaluate the hydrothermal state of architecture sites,and an assistance tool for architectural heritage protection was developped to verify and apply this theory’s function.Now,existing coupled heat and moisture transfer simulation tools can not fully meet the special needs of architectural heritages’ protection.So,based on the theory of hydrothermal coupled transfer,combining with real cases’ researches and model derivation,we designed and developed a simulation software for heat and moisture transfer simulation,which is applicable to architectural heritages,combing with relevant evaluation criterions,forming an assistance tool for architectural heritage protection.This tool will be helpful to the application and promotion of new technology on architrctural heritages’ preventive conservation.Firstly,we identified the internal relationship between heat,moisture and architectural diseases by investigating real cases;Then,based on the basic numerical model,a two-dimensional equilibrium equation of coupled heat and moisture transfer on interior and boundary conditions is established,and calculation method for this equation is given;In order to make this calculation method applicable to general cases and researchers,we designed an assistance tool in the order of main functions,operation logic and interface standards;Then we used computer languages to develop the interface and internal calculation program,and completing the development of the assiatance tool by the hybrid programming of calculation program and interface;After that,a comparasion of the simulation value and the actual measurement value of real case was conducted to vertify the feasibility and accuracy of this tool;At last,through the application of this tool in general architectural heritages case,it is proved that this assistance tool can paly a role in architectural protection,and provide technical support for analysis and ecaluation of architectural heritages.Development of this tool was an interdisciplinary explore.Through the simulation,analysis and software development,we can grasp the real-time hydrothermal fluctuations,evaluate the effectiveness and risk of the protection strategies.This study will not only provide scientific support to the preventive conservation of architectural heritages,but also promote the technology innovation of architectural protection,providing the scientific development of this field.Words: 55,000;Figures and tables:(85).