Preparation and Properties of a Composite Phase Change Energy Storage Gypsum Board Based on Capric Acid-Paraffin/Expanded Graphite

Abstract

Energy has become the key material basis of social development. In this work, liquid capric acid-paraffin was evenly adsorbed in the pore structure of expanded graphite (EG) by a physical adsorption method, and the new composite phase change material of capric acid-paraffin/expanded graphite (CA-P/EG) was prepared. The Fourier transform infrared (FT-IR) curves of CA-P/EG composites did not change after 1000 cycles, and there was no new characteristic absorption peak, indicating that CA-P/EG composites have good chemical stability. The results showed that the optimum content of CA-P/EG in a phase change energy storage gypsum board was 20%, and the wet bending strength and compressive strength were 2.42 and 6.45 MPa, respectively. The water absorption was 16.37%, and the apparent density was 1.410 g/cm 3 . In addition, the melting and freezing temperatures were 26.40 and 23.10 °C, and the latent heats of melting and freezing were 27.20 and 25.69 J/g, respectively. It was found that the gypsum board has excellent thermal stability after 400 times of melting−freezing cycling and that the heat storage capacity increases with the increase of the CA-P/EG content and the thickness of the gypsum board.

Preparation and Pore Structure of Energy-Storage Phosphorus Building Gypsum

“…However, the added value of phosphorous building gypsum products is relatively low owing to their poor mechanical properties and quality. Therefore, some researchers [ 15 , 16 , 17 , 18 , 19 ] have tried to use phosphorous building gypsum as an energy-storage building material to better improve its added value. Hua F et al [ 15 ] used Ca-P/EG as the carrier of a paraffin phase-change material and gypsum composite to prepare a phase-change gypsum board.…”

“…Therefore, some researchers [ 15 , 16 , 17 , 18 , 19 ] have tried to use phosphorous building gypsum as an energy-storage building material to better improve its added value. Hua F et al [ 15 ] used Ca-P/EG as the carrier of a paraffin phase-change material and gypsum composite to prepare a phase-change gypsum board. At 20% Ca-P/EG content, the gypsum board showed good thermal stability after 400 cycles of melting and freezing, but its compressive strength decreased by 44.87%.…”

“…In the abovementioned studies [ 15 , 16 , 17 , 18 , 19 ], the poor mechanical properties of energy-storage gypsum were mainly caused by the low strength of the porous phase-change material and the weak combination of the energy-storage aggregate encapsulating the material and gypsum. The leakage of the phase-change material in the energy-storage aggregate interfered with the hydration of the gypsum [ 20 ].…”

Multifunctional Carbon-Based Hybrid Foams for Shape-Stabilization of Phase Change Materials, Thermal Energy Storage, and Electromagnetic Interference Shielding Functions

“…One promising route to enhance the thermal conductivity of the final hybrid product (building component + PCM + ss) is the dispersion of high thermal conductivity additives into the PCM, such as (i) expanded graphite, (ii) carbon nanotubes (CNTs) or nanofibers, (iii) metal, and (iv) ceramic nanoparticles [19][20][21][22]. One other way to achieve the desirable reinforcement of the hybrids is to select a highly conductive ss matrix, such as metal foams and/or ceramic porous/foam structures [23][24][25].…”

Preparation and Characterization of Lauric–Myristic Acid/Expanded Graphite as Composite Phase Change Energy Storage Material

“…Sensible heat storage technology can store and release heat energy by changing the temperature of thermal insulation materials [6], and the technology was relatively mature but the storage density was low. Latent heat energy storage technology utilizes the characteristics of heat energy release and absorption of PCMs during the transition between solid phase and liquid phase [7,8], to achieve the goal of energy storage, temperature control, and energy recovery and reuse and balance the contradiction between energy supply and demand [9]. It has the advantages of high potential heat of phase transition, high energy storage density, and stable temperature output and has a broad application prospect in many fields such as building energy conservation [10,11], solar energy utilization [12][13][14], recycling and utilization of industrial exhaust heat [15], food storage [16], the balance of the electric power, and military infrared camouflage, getting more and more extensive attention.…”