Study On Preparation And Performance Of Binary Composite Phase Change Energy Storage Concrete

With the rapid development of our country in recent years,China’s energy consumption in the construction industry is huge,the most important of which is the energy consumed by the heating and cooling processes required to maintain the indoor temperature during the construction and use of the building.Implementing building energy efficiency and reducing building energy consumption is an important aspect of the national energy saving strategy.Phase change energy storage technology is one of the important measures to improve energy efficiency.Porous materials are used to adsorb phase change materials,and then phase change concrete is prepared,so that the concrete has a certain energy storage and temperature regulation effect,thereby reducing energy consumption.The main work includes:(1)This article uses melt blending to mix decanoic acid and lauric acid according to a certain mass ratio to prepare a binary composite phase change material.The step cooling curve method,differential scanning calorimetry method and theoretical calculation method are used to select the decanoic acid content as 50% decanoic acid-lauric acid composite phase change material is used as a phase change energy storage material.The phase change temperature is27.4℃,and the latent heat of phase change is 159.64 J/g.The phase change performance is stable after 200 freeze-thaw cycles.(2)Ultralight ceramsite and expanded perlite were used as adsorption carriers to adsorb the decanoic acid-lauric acid composite phase change material,and the vacuum adsorption was selected after studying the adsorption method and adsorption time.The maximum adsorption rates of ultralight ceramsite and expanded perlite under vacuum state were 54.2%and 214.4%,respectively.Testing of the phase change aggregates after adsorption has a phase change effect.A variety of materials are used to encapsulate the phase change aggregate.Finally,an epoxy resin-encapsulated cement powder packaging method is used to encapsulate the phase change ceramsite as the phase change aggregate.(3)Phase change ceramsite is used instead of ordinary ceramsite to prepare phase change ceramsite concrete.The basic properties,mechanical properties and thermodynamic properties of the phase change ceramsite are tested.It is found that as the replacement rate of phase change ceramsite increases,phase change ceramsite The dry apparent density and softening coefficient of concrete increased,and the water absorption decreased.The thermal conductivity of phase change ceramsite concrete is directly proportional to the replacement rate of phase change ceramsite.When completely replaced,the thermal conductivity is0.51,which exceeds the standard required by the code.The compressive strength of phase-change ceramsite concrete increases with the increase of the amount of phase-change ceramsite,and the split tensile strength decreases.The concrete with a phase change ceramsite substitution rate of 75% was selected as the roof building model.It was found that the temperature regulation effect was obvious and the temperature change could be delayed.