The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Yulong Ding - One of the best experts on this subject based on the ideXlab platform.
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Effects of Synthesis Methods on Thermal Performance of Nitrate Salt nanofluid for Concentrating Solar Power
Energy & Fuels, 2020Co-Authors: Yaxuan Xiong, Mingyuan Sun, Yulong DingAbstract:More than thirty thousand tons of molten Salts as efficient heat transfer and thermal energy storage materials, have been employed in a single commercial concentrating solar power plant. Nanopartic...
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simulation study of anomalous thermal properties of molten Nitrate Salt
Powder Technology, 2017Co-Authors: Geng Qiao, Alessio Alexiadis, Yulong DingAbstract:Abstract We performed Molecular Dynamics (MD) simulations to study the mechanism of the specific heat enhancement in Nitrate Salt based nanofluids. 26.6% enhancement of specific heat capacity was observed by introducing nanoparticles into the Salt system. Our simulations showed that the nanoparticles caused a layering effect in the adjacent region of the liquid molten Salt. Hence we attribute the enhancement in the specific heat capacity of molten Salts with the addition of nanoparticles to a previously undiscovered structural arrangement of Salt atoms around the nanoparticles.
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sodium Nitrate diatomite composite materials for thermal energy storage
Solar Energy, 2017Co-Authors: Cenyu Yang, Haisheng Che, Li Cong, Guanghui Leng, Yulong DingAbstract:Abstract The work reported in paper concerns the use of diatomite to form-stabilise sodium Nitrate, a phase change material (PCM) for medium temperature thermal energy storage applications. The composite was found to be able to retain up to 70% of the Nitrate Salt. X-ray diffraction (XRD) analyses suggested an excellent chemical compatibility between diatomite and the Salt. Scanning electron microscope (SEM) analyses demonstrated an even distribution of the Salt within the diatomite structure. Differential scanning calorimetry (DSC) measurements showed that melting temperature of the material was approximately 307.8 °C with a latent heat of 115.79 kJ/kg. Mechanical characterization of the composite material showed a compressive strength of the composite materials as high as 22.17 MPa. The composite materials were found to have a fairly low thermal conductivity of ∼0.5 W/m K and an addition of graphite could give a substantial thermal conductivity enhancement (∼6-fold with an additional of 10 wt% graphite).
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mechanical dispersion of nanoparticles and its effect on the specific heat capacity of impure binary Nitrate Salt mixtures
Nanomaterials, 2015Co-Authors: Mathieu Lasfargues, Qiao Geng, Hui Cao, Yulong DingAbstract:In this study, the effect of nanoparticle concentration was tested for both CuO and TiO2 in eutectic mixture of sodium and potassium Nitrate. Results showed an enhancement in specific heat capacity (Cp) for both types of nanoparticles (+10.48% at 440 °C for 0.1 wt % CuO and +4.95% at 440 °C for 0.5 wt % TiO2) but the behavior toward a rise in concentration was different with CuO displaying its highest enhancement at the lowest concentration whilst TiO2 showed no concentration dependence for three of the four different concentrations tested. The production of cluster of nanoparticles was visible in CuO but not in TiO2. This formation of nanostructure in molten Salt might promote the enhancement in Cp. However, the size and shape of these structures will most likely impact the energy density of the molten Salt.
Z G Wu - One of the best experts on this subject based on the ideXlab platform.
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thermal property characterization of a low melting temperature ternary Nitrate Salt mixture for thermal energy storage systems
Solar Energy Materials and Solar Cells, 2011Co-Authors: C Y Zhao, Z G WuAbstract:Abstract Molten Salts have better thermal properties than synthetic mineral oil, and hence they can be directly used as heat transfer fluids in solar power plants, but in practice their direct applications as heat transfer fluids are constrained due to their high freezing temperature points. In this paper, a class of ternary Nitrate Salt mixtures consisting of 50–80 wt% KNO 3 , 0–25 wt% LiNO 3 and 10–45 wt% Ca(NO 3 ) 2 were processed and tested. Experimental results indicated that some mixtures within this range exhibited excellent thermal properties, such as a low melting point (
Abdessamad Faik - One of the best experts on this subject based on the ideXlab platform.
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corrosion aspects of molten Nitrate Salt based nanofluids for thermal energy storage applications
Solar Energy, 2019Co-Authors: Udayashankar Nithiyanantham, Yaroslav Grosu, Abdelali Zaki, Luis Gonzalezfernandez, J M Igartua, Abdessamad FaikAbstract:Abstract Efficient energy storage is a bottleneck for nearly every renewable energy technology. Thermal energy storage (TES) is widely considered as a relatively simple and reliable method, particularly for concentrated solar power (CSP) plants. Currently, considerable scientific effort is focused on the development of new molten Salt-based nanofluids as storage materials with enhanced thermophysical properties and lower cost for TES purpose. However, an understanding of the effect of nanoparticles on the corrosivity of such nanofluids is practically absent. In the present work, using nanofluids based on eutectic mixture of NaNO3-KNO3 we demonstrate that nanoparticles doping has complex effects on the corrosion rates of carbon steel. In particular, if the negative effect of microbubbles of air trapped between the nanoparticles is not predominant, one can obtain reduced corrosion rates due to the incorporation of the nanoparticles into the oxidation layer. The obtained results are important both for expanding the very limited knowledge on the corrosion aspects of molten Salts-based nanofluids, as well as for comprehensive evaluation of the feasibility of such nanofluids for TES applications.
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A simple method for the inhibition of the corrosion of carbon steel by molten Nitrate Salt for thermal storage in concentrating solar power applications
npj Materials Degradation, 2018Co-Authors: Yaroslav Grosu, Udayashankar Nithiyanantham, Abdelali Zaki, Abdessamad FaikAbstract:Corrosion is an important issue in high-temperature applications such as Concentrated Solar Power (CSP) technology, playing a crucial role in the long-term use of storage tanks, heat exchanger and piping materials which account for a considerable component of the investment costs. While there are many studies regarding the corrosion rates of container materials under the conditions of CSP, there is little progress in the field of their degradation prevention by anticorrosion methods. This work presents an analysis of the corrosion mechanisms between the most economical construction material—carbon steel—and molten Nitrate Salt. A method to protect the carbon steel against corrosion by molten Salt at high temperature was proposed, involving the formation of a calcium carbonate layer on the carbon steel surface. The stability of the layer was tested under isothermal and temperature cycling conditions up to 500 °C, in both inert and air atmospheres in the presence or absence of humidity. The protection method proposed has potential to reduce investment costs for CSP technology. Spraying a thin coat of graphite on carbon steel can significantly improve their resistance to Nitrate Salts at high temperatures. A team led by Yaroslav Grosu and Abdessemad Faik from CIC Energigune in Spain used spray graphitization to coat the surface of a carbon steel before burying it in a Nitrate Salt mixture and heating it above 300 °C. Whether in air or in an inert atmosphere, and whether held above 300 °C in humidity or thermally cycled for 500 h up to 500 °C, the sprayed graphite consistently promoted the formation of stable calcium carbonate crystals at the steel surface. This protective calcium carbonate layer stopped the steel from oxidising. Inhibiting steel corrosion when in contact with molten Salts can help optimise materials for concentrated solar power technology and other high-temperature applications.
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unexpected effect of nanoparticles doping on the corrosivity of molten Nitrate Salt for thermal energy storage
Solar Energy Materials and Solar Cells, 2018Co-Authors: Yaroslav Grosu, Luis Gonzalezfernandez, Nithiyanantham Udayashankar, Oleksandr Bondarchuk, Abdessamad FaikAbstract:Abstract Molten Nitrate Salts are currently the most common mature solution for thermal energy storage at the concentrated solar power (CSP) plants. Enhancing heat capacity and thermal conductivity of molten Salts via doping by inorganic nanoparticles has attracted an explosively increasing interest due to the possibility of a considerable decrease of the investment costs for CSP technology. However, to the best of our knowledge there is almost no information on the effect of such doping on the corrosivity of the molten Salts. In this work we demonstrate that adding small amounts of nanoparticles into the molten Nitrate HitecXL Salt considerably increases its corrosivity and modifies the corrosion mechanisms. A set of advanced techniques such as SEM-EDX, XPS and XRD are applied to get insights into the effect of inorganic nano-additives on the corrosion phenomenon.
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compatibility of a post industrial ceramic with Nitrate molten Salts for use as filler material in a thermocline storage system
Applied Energy, 2013Co-Authors: Nicolas Calvet, Judith C. Gomez, Abdessamad Faik, Stefania Doppiu, Antoine Meffre, Greg C. Glatzmaier, Vladimir V. Roddatis, Xavier PyAbstract:This paper demonstrates the potential of a post-industrial ceramic commercially called Cofalit® as a promising, sustainable, and cheap filler material in a molten Salt direct thermocline storage system. This ceramic, which comes from industrial treatment of asbestos containing waste, demonstrates relevant properties to store thermal energy by sensible heat up to 1100°C and is very inexpensive. In the present study, the compatibility of this ceramic with two different molten Salts—the conventional binary Solar Salt and a promising ternary Nitrate Salt also called HITEC XL—is tested at medium temperature (500°C) under static state. The objective is to develop a molten Salt thermocline direct storage system using low-cost shaped ceramic as filler material. It should significantly decrease the cost of parabolic trough storage systems and simultaneously increase the efficiency of the plants by producing superheated steam at higher temperature.
C Y Zhao - One of the best experts on this subject based on the ideXlab platform.
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thermal property characterization of a low melting temperature ternary Nitrate Salt mixture for thermal energy storage systems
Solar Energy Materials and Solar Cells, 2011Co-Authors: C Y ZhaoAbstract:Abstract Molten Salts have better thermal properties than synthetic mineral oil, and hence they can be directly used as heat transfer fluids in solar power plants, but in practice their direct applications as heat transfer fluids are constrained due to their high freezing temperature points. In this paper, a class of ternary Nitrate Salt mixtures consisting of 50–80 wt% KNO 3 , 0–25 wt% LiNO 3 and 10–45 wt% Ca(NO 3 ) 2 were processed and tested. Experimental results indicated that some mixtures within this range exhibited excellent thermal properties, such as a low melting point (
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thermal property characterization of a low melting temperature ternary Nitrate Salt mixture for thermal energy storage systems
Solar Energy Materials and Solar Cells, 2011Co-Authors: C Y Zhao, Z G WuAbstract:Abstract Molten Salts have better thermal properties than synthetic mineral oil, and hence they can be directly used as heat transfer fluids in solar power plants, but in practice their direct applications as heat transfer fluids are constrained due to their high freezing temperature points. In this paper, a class of ternary Nitrate Salt mixtures consisting of 50–80 wt% KNO 3 , 0–25 wt% LiNO 3 and 10–45 wt% Ca(NO 3 ) 2 were processed and tested. Experimental results indicated that some mixtures within this range exhibited excellent thermal properties, such as a low melting point (
Donghyun Shin - One of the best experts on this subject based on the ideXlab platform.
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size effect of nanoparticle on specific heat in a ternary Nitrate lino3 nano3 kno3 Salt eutectic for thermal energy storage
Applied Thermal Engineering, 2016Co-Authors: Joohyun Seo, Donghyun ShinAbstract:Abstract In this study we investigate the effect of nanoparticles on the specific heat of ternary Nitrate Salt eutectic doped with nanoparticles. Four different sizes of SiO2 nanoparticles were tested: 5 nm, 10 nm, 30 nm, and 60 nm. They were doped into ternary Nitrate Salt eutectic (LiNO3–NaNO3–KNO3) at 1% concentration by weight. Ternary Nitrate Salt eutectic has been considered as advanced thermal energy storage material due to its lower melting point and high thermal stability. Enhancing the specific heat of ternary Nitrate Salt eutectic can greatly increase its thermal storage density. This can not only reduce the material cost but also the size of pipe and storage tanks and, therefore, energy storage cost can be significantly reduced. A modulated differential scanning calorimeter was employed to measure the specific heat of ternary Nitrate Salt eutectic before and after doping with nanoparticles. According to the conventional specific heat model (density weighted rule), the specific heat of ternary Nitrate Salt eutectic should slightly decrease after doping with nanoparticles since the concentration of nanoparticles is very small (∼1% by weight) and the specific heat of nanoparticles is lower than that of ternary Nitrate Salt eutectic. However, the specific heat of the mixture was measured to be enhanced by 13–16% and no significant variation in specific heat was observed with nanoparticle size. From subsequent material characterization study, we observed a large amount of nanometer-sized structure formed by the Salt compound around nanoparticles. Nanostructure has extremely large specific surface area. This can amplify the effect of surface energy on the effective specific heat (which was often negligible on a macroscale) and can be primarily responsible for the enhanced specific heat with doping nanoparticles.
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effect of nanoparticle dispersion on specific heat capacity of a binary Nitrate Salt eutectic for concentrated solar power applications
International Journal of Thermal Sciences, 2013Co-Authors: Bharath Dudda, Donghyun ShinAbstract:Abstract In this study we investigate nanoparticle dispersions in a molten binary Nitrate Salt eutectic. It has been recently reported that nanoparticle dispersions in molten Salt mixtures can significantly enhance the specific heat capacity of the Salt mixtures. These molten Salt mixtures can be used as heat transfer fluid (HTF)/thermal energy storage (TES) in a concentrated solar power (CSP) plant and enhancing their specific heat capacity can significantly reduce the cost of electricity produced by CSP. However, the mechanism for the enhanced specific heat capacity is still under investigation and has not been clearly explained. In this paper, we investigate the effect of nanoparticle size on the specific heat capacity of nanoparticle/molten Salt eutectic mixture. Four different sizes of nanoparticles (5 nm, 10 nm, 30 nm, and 60 nm) were dispersed in a molten Nitrate Salt eutectic at 1% concentration by weight. The molten Nitrate Salt eutectic consisted of sodium Nitrate (NaNO3) and potassium Nitrate (KNO3) at compositions of 60% and 40% by weight. A modulated differential scanning calorimeter (MDSC) was employed to measure the specific heat capacity of the pure molten Salt eutectic and the nanomaterials (pure molten Salt eutectic mixed with nanoparticles). The specific heat capacity of the nanomaterials was enhanced with increase of nanoparticle size. The observed enhancement was found to be 8% for 5 nm, 12% for 10 nm, 19% for 30 nm and 27% for the 60 nm. Material characterization analyses were carried out to investigate microstructural change of the nanomaterials. It was observed that special nanostructures were formed by molten Salt mixtures in the nanomaterial samples and the amount of observed nanostructures was increased with the measured specific heat capacity. This indicates that nanostructures formed in the nanomaterials may be responsible for the enhanced specific heat capacity of the nanomaterials.