Preparation And Application Of Fly Ash Matrix Phase Change Materials For Thermal Storage In Building Energy Conservation

With Chinese rapid economic development, energy supply and demand issues arebecoming more prominent. Large-scale development of conventional energy sources, aswell as looking for new alternative energy and energy-saving technology is alsoimperative. Energy storage technology, the use of phase change material is solid-liquidphase change latent heat to store thermal energy has broad application prospects inmany fields. Solid-liquid phase change latent heat storage technology concern becauseof its large energy storage density, storage temperature stability, and use of electricity,solar, waste heat recovery, and other fields have broad application space. Thepreparation phase change energy storage build materials which combined the phasechange material with a porous matrix used in the build envelope, the build indoortemperature fluctuation can be reduced and the indoor temperature can control in thehuman comfort temperature range, thereby reducing building energy consumption andachieving building energy efficiency.This paper introduces a new type of amorphous phase change composites—Cetylalcohol-Decanoic acid as a phase change material, its preparation, storagecharacteristics were measured. DSC measurements show that such composite phasechange material phase change temperature of25.5°C, the latent heat of203J g-1.Selection of building materials of fly ash as a matrix, through2hours of molten phasechange material and fly ash, phase change materials adsorbed on fly ash mass fractionof48%. After solidification of200,500times-thawing cycle experiments and foundthat the phase change material of this composite has a good heat cycle and chemicalstability, phase change material does not leak from the composite phase change materialin the molten state. Composite phase change material properties characterization byscanning electron microscopy method (SEM), X-ray diffraction (XRD), Fouriertransforms infrared spectroscopy (FT-IR), thermal gravimetric analysis (TG) wasmeasured. The test results show that the composite phase change material and fly ashstructure stability, good chemical compatibility, even at high temperature, its thermalstability is also better. To study the heat transfer performance to improve the situationby adding different mass fractions of expanded graphite, which added to the6%expanded graphite improved heat transfer performance.In order to detect the practical performance of the phase-change material, as well as to better promote the application of phase change materials in the building envelopeabove, adding fly ash storage materials and add wallboard specific heat test its heatstorage capacity estimate. Then was housing model with two wall panels constitute theapplication of experimental detection of the inner and outer wall temperature phasechange energy storage material added to reduce the role of the inner and outer walltemperature fluctuations effect and not a member of the housing of the phase changematerial model compared to the peak temperature is reduced approximately4℃and5°C; the peak temperature of the internal space also reduces the4°C. Therefore, as a newtype of composite phase change materials, Cetyl alcohol-Decanoic acid/fly ashcomposite phase change materials can be used in energy-efficient buildings.