Guiyin Fang

Preparation and characterization of flame retardant n-hexadecane/silicon dioxide composites as thermal energy storage materials

Flame retardant n-hexadecane/silicon dioxide (SiO(2)) composites as thermal energy storage materials were prepared using sol-gel methods. In the composites, n-hexadecane was used as the phase change material for thermal energy storage, and SiO(2) acted as the supporting material that is fire resistant. In order to further improve flame retardant property of the composites, the expanded graphite (EG) was added in the composites. Fourier transformation infrared spectroscope (FT-IR), X-ray diffractometer (XRD) and scanning electronic microscope (SEM) were used to determine chemical structure, crystalloid phase and microstructure of flame retardant n-hexadecane/SiO(2) composites, respectively. The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetric analysis apparatus (TGA), respectively. The SEM results showed that the n-hexadecane was well dispersed in the porous network of the SiO(2). The DSC results indicated that the melting and solidifying latent heats of the composites are 147.58 and 145.10 kJ/kg when the mass percentage of the n-hexadecane in the composites is 73.3%. The TGA results showed that the loading of the EG increased the charred residue amount of the composites at 700 degrees C, contributing to the improved thermal stability of the composites. It was observed from SEM photographs that the homogeneous and compact charred residue structure after combustion improved the flammability of the composites.

Synthesis and Characterization of Microencapsulated Paraffin Microcapsules as Shape-Stabilized Thermal Energy Storage Materials

This article presents the preparation and characterization of microencapsulated paraffin microcapsules with silicon dioxide (SiO2) shells as thermal energy storage materials. The microcapsules were prepared using a sol-gel method. Paraffin was used as the core material, and SiO2 prepared with methyl triethoxysilane (MTES) acted as the shell material. The morphology and particle size of the microcapsules were investigated using scanning electron microscopy (SEM). The chemical characterization of the microcapsules was measured using Fourier transform infrared spectroscope (FTIR). The crystalloid phase of the microcapsules was measured using X-ray diffraction (XRD). The thermal properties and thermal stability of the microcapsules were analyzed using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The FTIR, XRD, and SEM results showed that the paraffin was encapsulated in the shell of the SiO2. The DSC results indicated that the typical microcapsules melted at 57.96°C with a latent heat of 156.86 kJ/kg and solidified at 55.78°C with a latent heat of 144.09 kJ/kg at microencapsulation ratio of 82.2%. The TGA and DTG results showed that the microcapsules had good thermal stability. The SiO2 shells improved the thermal stability of the microcapsules.

Dynamic characteristics of cool thermal energy storage systems—a review

ABSTRACT Cool thermal energy storage (CTES) plays a significant role in conserving available energy, improving its utilization, and correcting the mismatch that occurs between the supply and demand of energy. It has been employed in many applications, for example, cool storage systems for air-conditioning and natural cooling of energy-efficient building. CTES is widely used in various industrial applications such as food and pharmacy processing, where large short duration loads are often required. This paper presents a review on CTES systems and characteristics. The dynamic characteristics of chilled water storage system, coil pipe cool storage system, packed bed cool storage system, gas hydrate cool storage system, and ice slurry cool storage system are analyzed and discussed. The applications of CTES system are summarized.

Experimental measurement on characteristics of cool storage air conditioning system

The experimental apparatus of cool storage air conditioning system is designed and constructed. The characteristics of cool storage air-conditioning system are experimentally measured. The temperature variation of coolant in the evaporator is presented by experiments. The refrigerant temperature in the evaporator and the compressor discharge temperature are also shown. The cool storage experiments are carried out to measure the refrigeration capacity of the chiller in cool storage mode, and the cool storage capacity in the storage tank. The measured results show that the coolant temperature difference between inlet and outlet in the evaporator, the refrigerant evaporating temperature, discharging temperature of the compressor and the refrigeration capacity of the chiller during cool storage period can maintain stable. The cool storage capacity in the storage tank approximately increases in linearity with cool storage time. This indicates the cool storage air conditioning system can stably operate.