scholarly journals A Novel Method for the Synthesis of Binary Molten Salt Nanofluids Adding SiO2 Nanoparticles

2020 ◽  
Author(s):  
Joohyun Seo
Keyword(s):  
Heat Capacity ◽  
Sample Preparation ◽  
Phase Change ◽  
Specific Heat ◽  
Molten Salt ◽  
Specific Heat Capacity ◽  
Sio2 Nanoparticles ◽  
Bottom Surface ◽  
Unexpected Result ◽  
Novel Method

Abstract In this study, the new method has been suggested for the synthesis of a binary molten salt eutectic adding nanoparticles (i.e. molten salt nanofluids). Solar salt (i.e. NaNO 3 -KNO 3 , 60:40 by weight) adding 10nm of SiO 2 nanoparticles was prepared to measure the specific heat capacity of molten salt nanofluids by a modulated differential scanning calorimeter (MDSC). In previous studies the sample preparation of a molten salt eutectic follows the same procedure. Each chemical of a molten salt eutectic and nanoparticles is dissolved in an aqueous solution. These homogeneous salts are completely mixed by a sonication. Nano-mixtures are scrapped off the bottom surface of a vial after drying. However, there are complex steps in the process of getting fresh molten salt eutectic nanofluids before MDSC measurements. An unexpected result is able to occur due to phase change (i.e. solid-liquid-solid) at each step and then it has an affect on the specific heat capacity of molten salt nanofluids. A suggested novel method (i.e. Liquid-to-Liquid) can not only prevent unexpected errors (e.g. the possibility of contamination) by phase change in the sample preparation, but also enhance the specific heat capacity of molten salt nanofluids.

Thermal Analysis of Phase Change Material Based Heat Transfer Fluid in Solar Thermal Collector

2020 ◽  
Author(s):  
Tyler J. E. O’Neil ◽  
Celine S. L. Lim ◽  
Sarvenaz Sobhansarbandi
Keyword(s):  
Heat Capacity ◽  
Phase Change ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Phase Change Materials ◽  
Solar Thermal ◽  
Heat Transfer Fluid ◽  
Liquid Form ◽  
High Specific Heat ◽  
Multi Walled Carbon Nanotubes

Abstract Phase change materials (PCMs) are commonly used as energy storage mediums in solar thermal systems. This paper investigates the mixture of PCM doped with nanoparticles to be used as HTFs directly integrated in a U-pipe ETC to be applied in solar thermal collectors. The selected type of PCM-HTF in this study is erythritol (C4H10O4), with high specific heat capacity in liquid form, as well as its unique sub-cooling behavior. In order to overcome the low thermal conductivity of erythritol and further enhance specific heat capacity, a weight concentration of 1% multi-walled carbon nanotubes (MWCNT) is added. Additionally, to insure even distribution of MWCNT and consistent properties of the HTF, triethanolamine (TEA) is proposed to be incorporated as a dispersant. The samples were each tested in a Thermogravimetric Analyzer (TGA) and Differential Scanning Calorimeter (DSC) to analyze their thermal properties. The results from the DSC tests show 12.4% enhancement of specific heat capacity of the proposed HTF mixture as well as nearly 5° C depression of freezing onset temperature. This study allows for the optimization of the operating temperature range of the collector when integrated with these materials, where direct heat gain can be obtained in the collector.

scholarly journals The Effects of Nanoparticles on the Specific Heat Capacity of Molten Salts

2018 ◽  
Vol 5 ◽  
pp. 56-65
Author(s):  
Alexander Foldi ◽  
Duy Khang Simba Nguyen ◽  
Yeong Cherng Yap
Keyword(s):  
Heat Capacity ◽  
Thermal Properties ◽  
Specific Heat ◽  
Molten Salt ◽  
Specific Heat Capacity ◽  
Molten Salts ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Efficiency Increase ◽  
Solar Power Plants

The desire to increase the efficiency of existing renewable energy sources has been thoroughly researched over the past years. This meta study aimed to investigate existing methods used by previous researchers to increase the Specific Heat Capacity of Molten Salt used for Concentrated Solar Power Plants. Investigations into nanoparticles were explored because of the effect of particle size and concentration can potentially increase the specific heat capacity of the molten salt. Numerous nanoparticles have shown to improve the thermal properties such as Silica (SiO2), Alumina (Al2O3), Titania (TiO2). Our summation was that the addition of nanoparticles into Molten Salts shows an increase in desired thermal properties of the Molten Salts. An efficiency increase of up to 28% was noted in the SHC (Cp) of the Molten Salts when Nanoparticles of 60nm were introduced.

scholarly journals Increment of specific heat capacity of solar salt with SiO2 nanoparticles

2014 ◽  
Vol 9 (1) ◽  
pp. 582 ◽  
Author(s):  
Patricia Andreu-Cabedo ◽  
Rosa Mondragon ◽  
Leonor Hernandez ◽  
Raul Martinez-Cuenca ◽  
Luis Cabedo ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Sio2 Nanoparticles ◽  
Solar Salt

scholarly journals The Effect of In Situ Synthesis of MgO Nanoparticles on the Thermal Properties of Ternary Nitrate

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5737
Author(s):  
Zhiyu Tong ◽  
Linfeng Li ◽  
Yuanyuan Li ◽  
Qingmeng Wang ◽  
Xiaomin Cheng
Keyword(s):  
Heat Transfer ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Specific Heat ◽  
Molten Salt ◽  
Specific Heat Capacity ◽  
Ternary Eutectic ◽  
Mgo Nanoparticles ◽  
Nitrate System

The multiple eutectic nitrates with a low melting point are widely used in the field of solar thermal utilization due to their good thermophysical properties. The addition of nanoparticles can improve the heat transfer and heat storage performance of nitrate. This article explored the effect of MgO nanoparticles on the thermal properties of ternary eutectic nitrates. As a result of the decomposition reaction of the Mg(OH)2 precursor at high temperature, MgO nanoparticles were synthesized in situ in the LiNO3–NaNO3–KNO3 ternary eutectic nitrate system. XRD and Raman results showed that MgO nanoparticles were successfully synthesized in situ in the ternary nitrate system. SEM and EDS results showed no obvious agglomeration. The specific heat capacity of the modified salt is significantly increased. When the content of MgO nanoparticles is 2 wt %, the specific heat of the modified salt in the solid phase and the specific heat in the liquid phase increased by 51.54% and 44.50%, respectively. The heat transfer performance of the modified salt is also significantly improved. When the content of MgO nanoparticles is 5 wt %, the thermal diffusion coefficient of the modified salt is increased by 39.3%. This study also discussed the enhancement mechanism of the specific heat capacity of the molten salt by the nanoparticles mainly due to the higher specific surface energy of MgO and the semi-solid layer that formed between the MgO nanoparticles and the molten salt.

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