Investigation on properties of phase change foamed concrete mixed with lauric acid-hexadecanol/fumed silica shape-stabilized composite phase change material

• Published in: Construction & building materials Vol. 394; p. 132274
• Main Authors: Wei, Pengfei, Yin, Guansheng, Shi, Minghui, Zhang, Wanqi, Zhang, Jintao, Hao, Wenqian, Feng, Junjie
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 29.08.2023
• Subjects: Composite phase change material; Fumed silica; Heat storage capacity; Phase change foam concrete; Phase change foam concrete; Composite phase change material; Heat storage capacity; Fumed silica
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2023.132274

•Lauric acid-Hexadecanol (LA-HD) binary eutectic PCM were prepared by melt blending.•The validity and accuracy of theoretical calculation of binary eutectic were demonstrated by experiments.•LA-HD/Fumed silica shape-stabilized composite PCM were prepared by porous material adsorption method with hydrophobic fumed silica as the carrier.•Three kinds of composite PCFC wall models were designed and their thermal storage and heat transfer performance were simulated.•The PCFC has a positive significance for the heat storage and heat transfer of the wall and it is better to arrange it inside the walls. This experimental study developed a phase change foamed concrete (PCFC) with suitable temperature regulation and heat storage capabilities utilizing experimental design and numerical simulation. With the porous material adsorption method, a shape-stabilized composite phase change material (PCM) was prepared using fumed silica to absorb Lauric acid-Hexadecanol (LA-HD) binary eutectic. Through the Differential Scanning Calorimetry (DSC), Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectrometer (FT-IR), Thermal Gravimetric Analyzer (TGA) and liquid leakage tests, the results indicate that the best mass ratio of LA to HD in LA-HD binary eutectic is 53:47. The maximum adsorption ratio of fumed silica for LA-HD is 60 % (wt). The adsorption process is only a physical combination without chemical reaction, and the proposed composite PCM has stable morphological structures and physical properties. The effect of composite PCM on the dry density, compressive strength and thermal properties of PCFC was explored by changing the content (5 %, 10 %, 15 %, 20 %, 25 %, 30 %) of composite PCM in PCFC. The finite element software ABAQUS was used to establish the model of the PCFC wall, and its heat storage and temperature regulating performance was studied. The experiment results show that the dry density, compressive strength and thermal conductivity of the PCFC gradually decrease with the increase of composite PCM. When the content of composite PCM is 30 %, the dry density, compressive strength and thermal conductivity reach the minimum values of 579.6 kg/m3, 1.192 MPa and 0.105 W/(m·K), respectively. With the increase of composite PCM, the phase change temperature, latent heat and specific heat capacity of foam concrete also increase. When the content of composite PCM is 30 %, the phase change temperature is 36.13 °C, the latent heat is 35.02 J/g, and the specific heat capacity is 2467 J/(kg·°C). The finite element simulation results show that when the PCFC with 30 % composite PCM is placed in the middle of the wall, the inside surface temperature fluctuation range of the PCFC-wall-2 is 27.293 °C ∼ 28.707 °C, and the temperature difference is 1.414 °C, which is 0.0738 °C and 0.047 °C lower than that of PCFC-wall-1 and PCFC-wall-3, respectively; the time for PCFC-wall-2 to reach the peak and valley temperature is delayed by 0.1667 h than the other two walls. The results indicate that using PCFC in buildings can reduce the energy required for building cooling or heating and affect energy saving and environmental protection. Moreover, PCFCs arranged in the middle of the wall has better heat storage and temperature regulation effect than those arranged on both sides.