Modification on hydrated salt‐based phase change composites with carbon fillers for electronic thermal management

Abstract

Summary For electronic thermal management with hydrated salt phase change materials (PCM), supercooling and thermal stability usually inhibit its development. In view of this, novel of disodium hydrogen phosphate dodecahydrate (DSP)‐based composites PCM with miniaturized size is developed to solve these problems. Three kinds of carbon fillers employed as both nucleating agent and heat transfer promoter were added in DSP separately. The influences of carbon fillers' specific surface area, particle size, and adsorption mode on thermal properties of DSP‐based composites PCM were investigated experimentally. The thermal conductive chains of composites PCM were detected by energy dispersive spectroscopy. The supercooling degree was analyzed by melting‐freezing test. Temperature‐regulated property was captured by infrared imager. In the present work, the supercooling degree of GNS/DSP composites PCM is efficiently reduced to 97.24% compared with the pure DSP. Negligible change in phase change temperature of the CNTS/DSP composites PCM was confirmed after 200 times cycles. There was no obvious liquid leakage of DSP when 2 wt% of carbon fillers were added in composites PCM. The enhancement on thermal properties of DSP is a promising strategy for numerous thermal applications.

PHASE CHANGE MATERIALS: TYPES, PROPERTIES and APPLICATIONS in BUILDINGS

“…Salt and salt hydrates are abundant sources in salt lakes or seawater, therefore it is cost-competitive with a price of one percent of paraffin. The fair cost and non-flammable characteristics of inorganic phase change materials provide much greater encouragement for commercialization than organics [25]. Salt…”

Gas film heat transfer as enhancement strategy for phase change materials

“…which means that the heat transfer is controlled by the film. Finally, it is interesting to compare the stationary power predicted by Equation (10) using a film layer and the power from traditional approaches, that is, by direct contact of the solidified layer with the wall and its continuous growth given by Equation (1). By dividing Equation (10) with Equation (1) one obtains the ratio between the density powers as…”

“…Those techniques of heat transfer enhancement based in adapted geometric configurations and extended surfaces; and those techniques in which heat transfer enhancement is attained by directly modifying in some way the thermal conductivity of the PCM. In the first category we have, for example, the use of fins, heat pipes, or fillers, and in the second category we have the use of encapsulation; or microencapsulation of the PCM as well as the use of nanoparticles including nanotubes or nanocomposites . There are copious available literature of the topic and specially in the last advancements in PCMs, and for the interested reader on various techniques of heat transfer enhancement in latent heat thermal energy storage systems it is recommended the up‐to‐date review on the state‐of‐the‐art as well as critical review …”

Preparation and characterization of erythritol/polyaniline form‐stable phase change materials containing silver nanowires

“…But it is believed that large number of nucleating centers, and thus high heterogeneous nucleation rate, are beneficial for the suppression of supercooling. 4,[24][25][26] For example, the supercooling of ME could be decreased to 64°C due to the graphitic surface of graphite foams, and carbon nanotubes provided a great number of nucleating centers. 19 Wang et al 4 also found that the supercooling of ME could be decreased by 83.6% with the help of silica shell with high surface area and the restricted molecular movement caused by a thickener.…”

“…Hence, it is expectable that form-stable PCMs, in which sugar alcohols and polymers act as solid-liquid PCMs and supporting materials, respectively, can exhibit high latent heat storage capacity. 4,[24][25][26] For example, the supercooling of ME could be decreased to 64°C due to the graphitic surface of graphite foams, and carbon nanotubes provided a great number of nucleating centers. For example, the melting points of ME and D-mannitol are about 118°C and 166°C, respectively.…”