Study On Thermal Storage Properties Of Phase Change Material Walllboards With Water-heating System

In the United Nations Framework Convention on Climate Change of2009， our countrysolemnly submitted commitments of energy conservation and greenhouse gas emissionreduction plan till2020. Nowadays, the years of "Twelve-Five" project is coming. In order tospeed up the process of resource-saving and environment-friendly society, China will face amore severe task of energy-saving and emission reduction. Recently, about2billion squaremeters of new buildings were built every year, which is equivalent to40%of new buildings’cement and steel consumption. It can be seen that whether the energy saving object inconstruction industry be come true is able to ease the strain of energy supply and demandsituation in China, which also brings more and more opportunities and challenges.In thissituation, new kinds of phase change materials aimed to reduce the energy consumption inbuildings came into being.PCMs has higher heat capacity and lower thermal conductivity than common buildingmaterials, which can effectively increase the thermal inertia of light building materials, absorband release heat through phase transition process. Under the situation of outdoor temperature,an appropriate phase change temperature and latent heat can be selected and jointed intobuilding envelope, in order to maintain certain temperature and heat flux on building envelopestructure surface, and then achieve energy-consuming reduction. What this paper researcheswas a kind of phase change wallboard with water heating system, into which were added acertain kind of PCM by different methods. Through experiment and simulation of ANSYSdefinite element analysis software, hot water was supplied for8hours, and then stopped8hours. During this period, the heat transfer property, heat absorption and release situation ofdifferent kinds of low temperature hotwater were tested. So the feasibility and superiority ofPCM wallboard with water heated intermittently were proved, as well as the optimizationselection of PCMs, the way and amount of PCM jointed, and the temperature of heatingwater.The research results show that PCMs jointed into wallboard can effectively enhance thethermal resistance and thermal inertia of the wallboard, as well as keep a certain range ofindoor temperature. In theory, shape-stabilized phase change materials can replace the outerinsulation of building; when added the outer insulation material, the heat absorption andrelease ability of phase change wallboard can be improved. In this paper, the major and secondary factors which influence the heat release of PCM wallboard were given. Bycomparing different thickness and location of phase change material in the wallboard, theoptimization solutions of water-heated PCM wallboard can be found. Results in this paper canprovide references and basis for the heat transfer enforcement of phase change materials usedin the wall and floor.