Sonocrystallization Technique to Optimizing the Crystallization Process of PCM CaCl&lt;sub&gt;2&lt;/sub&gt;.6H&lt;sub&gt;2&lt;/sub&gt;O

Palittin, Ivylentine Datu; Kurniati, Nani; Sutjahja, Inge Magdalena; Kurnia, Dadang

doi:10.4028/www.scientific.net/amr.1112.559

Cited by 4 publications

(4 citation statements)

References 5 publications

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“…It was found that SrCl 2 ·6H 2 O exerted the best effect on CaCl 2 ·6H 2 O, this result was consistence with paper [25]. Palittin [26] adopted sonocrystallization method which used ultrasound radiation for promoting CaCl 2 ·6H 2 O to crystallize and results indicated this technique made crystals have uniform distribution and dense arrangement. Analogously, Miyasaka et al [27] observed that ultrasound irradiation exceled in controlling primary nucleation of Na 2 HPO 4 ·12H 2 O and suggested that nucleation induced by ultrasound was probably the main cause of temperature rise.…”

Section: Supercooling Of Salt Hydratesmentioning

confidence: 49%

Inorganic Salt Hydrate for Thermal Energy Storage

et al. 2017

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Using phase change materials (PCMs) for thermal energy storage has always been a hot topic within the research community due to their excellent performance on energy conservation such as energy efficiency in buildings, solar domestic hot water systems, textile industry, biomedical and food agroindustry. Several literatures have reported phase change materials concerning various aspects. Among these materials, salt hydrates are worthy of exploring due to their high-energy storage density, rational price, multiple sources and relatively good thermal conductivity. This paper reviews the present state of salt hydrates PCMs targeting classification, properties, defects, possible solutions as well as their idiographic features which are suitable for applications. In addition, new trends of future research are also indicated.

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Section: Supercooling Of Salt Hydratesmentioning

confidence: 49%

Inorganic Salt Hydrate for Thermal Energy Storage

et al. 2017

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“…In the case of CaCl 2 ·6H 2 O, the increase in mechanical energy by mechanical treatment led to a decrease in the supercooling degree [50]. The results of the use of ultrasound irradiation in CaCl 2 ·6H 2 O are not as clear and meaningful as water or salt [51][52], although they show similar bubble formation.…”

Section: Resultsmentioning

confidence: 99%

Electrofreezing of the phase-change material CaCl2•6H2O and its impact on supercooling and the nucleation time

Sutjahja

Rahman

Putri

et al. 2019

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This paper reports electrofreezing experiments on the inorganic phase-change material (PCM) CaCl 2 ·6H 2 O by using an insulated copper electrode that is commonly sold in the market. The effect of the applied voltage or electric field to the nucleation process is measured by the nucleation temperature, freezing temperature, supercooling degree, induction time, time for supercooling, and time for crystallisation. It is found that, compared to the zero field, the freezing temperature remains nearly constant while the nucleation temperature increases with increasing applied field, leading to a reduction in the supercooling degree. The decrease in the supercooling degree is approximately 6 K for an applied voltage of V = 5.0 kV or E = 10 7 V m -1 . With the increase in the applied field the induction time decreased considerably along with reduction of the measured data spread as compared to the no-voltage case, while the crystallisation time for the phase transformation prolonged. The overall phenomena are analysed in terms of modification of the Gibbs free energy for crystallisation owing to the applied field, with the mechanism involving bubble generation and formation of a copper-chloride complex. 364A common way to initiate the solidification process and reduce the supercooling of PCMs, and in particular, a salt hydrate, from the solution is by seeding or adding an appropriate nucleating agent, usually in the form of nanoparticle powders, to form a stable suspension with the salt hydrate solution [12]. Lane [13] reported that the choice of the nucleating agent is usually by trial and error, guided by intuition or experience, and by using the chemical dopants which are ready in stock and on a laboratory shelf. From the crystallographic perspective, the nucleators of CaCl 2 ·6H 2 O are classified as isomorphic and non-isostructural nucleators [13]. In general, the nucleator can impact the change in thermophysical parameters, such as the supercooling temperature, supercooling degree, specific heat, and the latent heat enthalpy. Recently, Sutjahja et al. [14] reported the effectiveness of 1 wt% CuO to reduce the supercooling degree and further modify the thermal parameters of CaCl 2 ·6H 2 O by graphite and CuO dopants, although logical explanations for their effectiveness apparent do not exist.The effect of electrical energy on the behaviour of supercooled fluids has been studied since two decades ago [15][16] and is commonly called electrofreezing or electronucleation; see [17][18][19] for the review and references therein. In most of the past experiments water droplets were mainly exposed to high-voltage electric fields, with the success expressed by higher nucleation temperatures, reduction in the supercooling degree, lowering the induction times, and increased nucleation probability. Recently, the effectiveness of electrofreezing has also been reported for some other materials, such as erythritol polyalcohol [20], tetra-n-butyl ammonium bromide (TBAB) clathrate hydrates [21][22], tetrahydrofuran (THF) clathrate ...

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“…Compared with organic and eutectic PCMs, low-cost inorganic PCMs have a high latent heat of fusion, high thermal conductivity, small volume change, and narrow phasechange temperature range. However, supercooling is one of the drawbacks of inorganic PCMs, leading to operating temperature delay and phase separation [5,[7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

“…Among the additives, SrCL 2 •6H 2 O showed the best performance in preventing supercooling. Palittin [10] adopted sonocrystallization by using ultrasound radiation to crystallize CaCl 2 •6H 2 O. In order to minimize phase segregation, thickener agents have been used.…”

Section: Introductionmentioning

confidence: 99%

Thermophysical Properties of Inorganic Phase-Change Materials Based on MnCl2·4H2O

et al. 2022

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Manganese (II) chloride tetrahydrate, classified as an inorganic phase-change material (PCM), can be used as a thermal energy storage material, saving and releasing thermal energy during its phase transitions. In this study, thermophysical properties, such as phase change temperatures, latent heat, and thermal conductivities, of four types of MnCl2·4H2O PCMs were investigated under single and dual phases (liquid-, solid-, and dual-phase PCMs) using differential scanning calorimetry (DSC) and a heat flow meter. PCMs with a liquid or dual phases exhibited superheating issues, and their melting temperatures were 7 to 10 °C higher than the reference melting temperatures. The PCMs had latent heats between 146 and 176 J/g in the temperature range of 23 to 45 °C under the endothermic process. Severe supercooling during the exothermic process was observed in all as-received specimens, but was mitigated in the homogenization-treated specimen, which sustained an increase in solidification temperature of about 15 °C compared with the as-received and treated PCMs. The diffusivities of PCMs were between 9.76 × 10−6 and 2.35 × 10−5 mm2/s. The diffusivities of the PCMs in the solid phase were higher than those in the liquid phase. During the initial holding time of the endothermic process, the PCM in the liquid phase could not be fully solidified due to an insufficient initial holding time and very low diffusivity, which caused superheating during the DSC measurement. Moreover, in the exothermic process, a fast cooling rate of 5 °C/min and low thermal diffusivity caused supercooling. In particular, the diffusivity of the liquid PCM was lower than those of the solid PCM and other PCMs, which caused extremely high supercooling during the DSC measurement. This paper provides the thermophysical properties of MnCl2·4H2O PCMs, which are not available in the literature. The homogeneity of PCMs in their initial states and their heating/cooling rates were identified, and constitute important factors for accurately measuring the thermophysical properties of PCMs.

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Sonocrystallization Technique to Optimizing the Crystallization Process of PCM CaCl<sub>2</sub>.6H<sub>2</sub>O

Cited by 4 publications

References 5 publications

Inorganic Salt Hydrate for Thermal Energy Storage

Inorganic Salt Hydrate for Thermal Energy Storage

Electrofreezing of the phase-change material CaCl2•6H2O and its impact on supercooling and the nucleation time

Thermophysical Properties of Inorganic Phase-Change Materials Based on MnCl2·4H2O

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