Showing papers by "Yutang Fang published in 2016"

A capric–palmitic–stearic acid ternary eutectic mixture/expanded graphite composite phase change material for thermal energy storage

Abstract: This paper demonstrated a capric acid–palmitic acid–stearic acid ternary eutectic mixture/expanded graphite (CA–PA–SA/EG) composite phase change material (PCM) for low-temperature heat storage. The CA–PA–SA ternary eutectic mixture with a mass ratio of CA:PA:SA = 79.3:14.7:6.0 was prepared firstly, and its mass ratio in the CA–PA–SA/EG composite can reach as high as 90%. The melting and freezing temperatures of CA–PA–SA/EG composite were 21.33 °C and 19.01 °C, and the corresponding latent heat were 131.7 kJ kg −1 and 127.2 kJ kg −1 . The CA–PA–SA/EG composite powders can be formed into round blocks by dry pressing easily, with much higher thermal conductivity than CA–PA–SA. Thermal performance test showed that the increasing thermal conductivity of CA–PA–SA could obviously decrease the melting/cooling time. Thermal property characterizations after 500 heating/cooling cycles test indicated that CA–PA–SA/EG composite PCM had excellent thermal reliability. Based on all these results, CA–PA–SA/EG composite PCM is a promising material for low-temperature thermal energy storage applications.

Preparation and Thermal Performance of Silica/n-Tetradecane Microencapsulated Phase Change Material for Cold Energy Storage

Abstract: A novel silica (SiO2)/n-tetradecane microencapsulated phase change material (MEPCM) was synthesized by in situ interfacial polycondensation. The influences of the amount of the composite emulsifier and the mass ratio of n-tetradecane and tetraethyl silicate on the MEPCM performance were systematically investigated. The morphology, chemical structure, and composition of the MEPCM were characterized by scanning electron microscopy and energy dispersive X-ray spectrometer, Fourier transform infrared spectroscopy, and X-ray diffraction, and its thermal performance and thermal stability were measured by differential scanning calorimetry and thermogravimetric analysis. The results showed that the n-tetradecane core material was successfully encapsulated by silica shell material with encapsulation ratio of 62.04%. The MEPCM had a melting enthalpy of 140.5 kJ kg–1 and thermal conductivity of 0.139 W m–1 K–1. Because of its excellent thermal performance and thermal stability, silica/n-tetradecane MEPCM displays a ...

Inorganic/organic composite casing layer nanometer phase-change capsule cool-storage fluid and preparation method thereof

Abstract: The invention belongs to the field of a phase change material technology for cool storage, and discloses an inorganic/organic composite casing layer nanometer phase-change capsule cool-storage fluid and a preparation method thereof. The preparation method comprises the following steps: hydrolysis and condensation are carried out for metal alkoxide, modification is carried out with an organosilicon coupling agent, modified metal oxide sol is obtained; a styrene monomer, an acrylic ester comonomer, a chain transferring agent, an initiator and an alkane core material are mixed for forming an oil phase, the oil phase is added into an emulsifier and deionized water for forming a water phase, homogeneous emulsification is carried out, and miniemulsion is obtained; the miniemulsion is heated to 40-80 DEG C, in situ polymerization is carried out for 10-50 minutes, the modified metal oxide sol is added drop by drop, and after a reaction, a composite casing layer nanometer phase change capsule emulsion is obtained; the emulsion is added into an antifreeze, water is added for dilution, and the product is obtained. Metal oxide and organic polymers are compounded into a casing layer; the product has the advantages of high heat conduction performance, high specific heat capacity and good mechanical stability at the same time, and the product can be used as phase-change cool-storage fluid for cool storage air-conditionings.

Method for reducing condensate depression of hydrous salt phase change material by adding antisolvent

Abstract: The invention belongs to the technical field of phase change materials and discloses a method for reducing condensate depression of hydrous salt phase change material by adding an antisolvent. The method for reducing the condensate depression of the hydrous salt phase change material by adding the antisolvent comprises the following steps: in a closed device, adding hydrous salt powder, degassing, so as to remove the air and water vapour, and introducing nitrogen for protection; heating the hydrous salt to be completely molten, then adding the antisolvent, stirring, and uniformly mixing, so as to obtain mixed liquor; and cooling the mixed liquor until the hydrous salt is completely crystallized, so that the hydrous salt phase change material with the condensate depression reduced is obtained. The method for reducing the condensate depression of the hydrous salt phase change material by adding the antisolvent has the advantages that the antisolvent is added, so that solubility of the hydrous salt can be reduced, supersaturation driving force of a hydrous salt solution is increased, and the condensate depression of the hydrous salt solution is reduced; meanwhile, the antisolvent is not externally replenished, a melting process is thorough, and the obtained system is stable in properties, so that the method disclosed by the invention has a good application prospect.