scholarly journals Thermal Stability and Reliability Test of Some Saturated Fatty Acids for Low and Medium Temperature Thermal Energy Storage

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4509
Author(s):  
Abhishek Anand ◽  
Karunesh Kant ◽  
Amritanshu Shukla ◽  
Chang-Ren Chen ◽  
Atul Sharma
Keyword(s):  
Fatty Acids ◽  
Energy Storage ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Saturated Fatty Acids ◽  
Heat Of Fusion ◽  
Gravimetric Analysis ◽  
Ternary Blends ◽  
Latent Heat Storage

Phase change materials have been overwhelmingly used for thermal energy storage applications. Among organics, fatty acids are an important constituent of latent heat storage. Most of the saturated fatty acid PCMs so far studied are either unary or binary constituents of pure fatty acids. In the present study, ternary blends of saturated fatty acids i.e., capric, lauric, myristic, stearic, and palmitic acids have been developed with different weight proportions. A series of 28 ternary blends viz. CA-LA-MA, CA-LA-PA, CA-LA-SA, CA-MA-PA, CA-MA-SA, and CA-PA-SA were prepared and analyzed with differential scanning calorimetry, thermal gravimetric analysis, and Fourier transform infrared spectroscopy. DSC analysis revealed that the prepared materials lie in the 15–30 °C temperature range. Also, 300 thermal melt/freeze cycles were conducted which showed ±10% variation in terms of the melting peak for most of the PCMs, with the average latent heat of fusion between 130 and 170 kJ/kg. The TGA analysis showed that most of the PCMs are thermally stable up to 100 °C and useful for medium-low storage applications, and FTIR analysis showed that the materials are chemically stable after repeated thermal cycles. Based on cycle test performances, the developed materials were found to be reliable for long-term use in building and photovoltaic applications.

scholarly journals Development of Binary Eutectic Organic Phase Change Materials for Solar Thermal Energy Storage Systems

2019 ◽  
Vol 9 (2) ◽  
pp. 2207-2210
Keyword(s):  
Energy Storage ◽  
Melting Point ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solar Thermal ◽  
Heat Of Fusion ◽  
Solar Thermal Energy ◽  
Latent Heat Of Fusion ◽  
High Latent Heat

Solar thermal energy storage unit anchored fatty acids as Phase Change Materials (PCMs) having narrow range of transition temperature and high latent heat of fusion. In this paper, a new novel eutectic PCM was developed by using a fatty acid (acetamide) and non-paraffin organic PCM (acetanilide) for a sharp melting point and high latent heat of fusion. The optimized eutectic PCM may be used for middle temperature range solar thermal energy storage systems. The binary mixture of acetamide and acetanilide at various compositions by mass ratio (wt%) was prepared and optimized experimentally for lowest value of melting point at a eutectic mixture composition of 60 wt% of acetamide and 40 wt% of acetanilide. Eutectic PCM was analyzed by Differential Scanning Calorimetry (DSC) and Field-Emission Scanning Electron Microscopy (FE-SEM). DSC results revealed that optimized eutectic PCM has a sharp melting point of 65.37°C and high latent heat of fusion of 224.67 kJ/kg. Accelerated thermal cycle testing of optimized eutectic PCM was performed for 100 melting and freezing cycles and change in melting temperature and latent heat of fusion was acceptable.

Modelling of latent thermal energy storage systems

2017 ◽  
Vol 8 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Z. Andrássy ◽  
Z. Szánthó
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Cfd Simulation ◽  
Storage System ◽  
Experimental System ◽  
Latent Heat Storage

In this paper phase change materials are presented, as effective thermal energy storage due to their great latent heat storing possibility. The main substance used for thermal energy storage purposes is water. Storing the energy with water is not that effective as with phase change materials, because the temperature of water has to change, and it worsen the heat exchange intensity. On the other hand, with phase change materials the temperature of the material does not have to change due to the latent heat storage possibilities. A buffer tank with two pipe coils filled with phase change materials is investigated with the aim to reduce the storage volume. An own thermodynamic model, a CFD simulation and an experimental system are presented. The models could be validated and the process of phase change could be examined with a life-size thermal energy storage system in the laboratory of the department. The performance of heat absorption and release of the phase change material could be calculated in the function of inlet water temperature and mass flow.

scholarly journals Evaluation of Formate Salt PCM’s for Latent Heat Thermal Energy Storage

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 765
Author(s):  
Samuel Gage ◽  
Prashant Sharan ◽  
Craig Turchi ◽  
Judy Netter
Keyword(s):  
Energy Storage ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Sodium Formate ◽  
Heat Of Fusion ◽  
Ftir Analysis ◽  
Sodium Potassium ◽  
Sodium Calcium ◽  
Calcium Formate

This work examines formate salts as potential phase change materials (PCMs) for middle-high temperature (≤250 °C) latent heat thermal energy storage applications. The thermophysical properties of three formate salts were characterized: pure sodium formate and binary blends of sodium/potassium formate and sodium/calcium formate. The stability of formate PCM’s was evaluated by thermal cycling using differential scanning calorimetry where sodium formate and sodium/potassium formate appeared stable over 600 cycles, while sodium/calcium formate exhibited a monotonic decrease in heat of fusion over the test period. A longer test with sodium formate led to gas release and decomposition of the salt. FTIR analysis of the PCM showed degradation of formate to oxalate. T-history experiments with 50-g PCM quantities demonstrated a bulk supercooling of only 2–3 °C for these salts. Thermal conductivity enhancement of over 700% was achieved by embedding aluminum in the solid PCM. Finally, mild carbon steel was immersed in molten sodium formate for up to 2000 h. Sodium formate was found to be non-corrosive, as calculated by mass loss and confirmed by cross-sectional high-resolution microscopy. FTIR analysis of the PCM after 2000 h shows oxidation at the free surface, while the bulk PCM remained unchanged, further indicating a need to protect the formate from atmospheric exposure when used as a PCM.

Microstructure and thermal characteristics of Mg–Sn alloys as phase change materials for thermal energy storage

RSC Advances ◽  
2016 ◽  
Vol 6 (98) ◽  
pp. 96327-96333 ◽  
Author(s):  
Dong Fang ◽  
Xiaomin Cheng ◽  
Yuanyuan Li ◽  
Zheng Sun
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Thermal Characteristics ◽  
Latent Heat Storage

Latent heat storage proves to be one of the most efficient ways of storing thermal energy.

scholarly journals Eutectic composition of selected phase change materials for thermal energy storage applications

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Olakunle F Isamotu ◽  
Nicholas A Musa ◽  
Joshua B Aluko ◽  
Maclawrence A Oriaifo
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Eutectic Mixture ◽  
Melting Points ◽  
Latent Heat Storage

Latent heat storage in salt mixture has drawn so much attention because of the salt mixture’s capability of storing   large quantity of heat when compared to single salt thereby, making it more feasible for use as phase change material.  However it is worthwhile to find out among various combination of salts forming eutectic   mixtures, the one that has the best energy storage capability by evaluating   and comparing their melting points and latent heat storage. So in this research work, four different types of eutectic mixture of   salts were prepared and experimentally   investigated for the best thermal energy storage capability.  The first eutectic mixture consists of 2.6g of LiNO3, 6.4g of NH4NO3   and 1g of NaNO3. The second eutectic mixture consists of1.75g of LiNO3,   3.9g of NH4NO3 and 1.1g of KNO3. The third one consists of 5.2g of   LiNO3, 13.7g   of NH4NO3 and 1g of NH4Cl) and the fourth one consists of 1.77g of LiNO3, 2.94g of NH4NO3,  1g of NaNO3 and 1g of NaCl. The latent heat and the melting point of the respective salt and their eutectic mixture were determined using digital differential scanning Apparatus.  The results obtained showed that the melting points and latent heats of  the first, second, third and fourth eutectic mixture  were 79.50C and 112kJ/kg,  80.50C and 114kJ/kg,  81.40C and 109kJ/kg,  84.40C and 119kJ/kg respectively.  In view of this, the eutectic mixture of 1.77g of LiNO3, 2.94g of NH4NO3, 1g of NaNO3 and 1g of NaCl with melting point of 84.40C and latent heat of 119KJ/Kg was found to possess the best thermal energy storage capability compared to others..Keywords—Eutectic mixture, Salts, Phase change materials (PCM), Latent heat storage

scholarly journals Review on the Integration of Phase Change Materials in Building Envelopes for Passive Latent Heat Storage

2021 ◽  
Vol 11 (19) ◽  
pp. 9305
Author(s):  
Mohamed Sawadogo ◽  
Marie Duquesne ◽  
Rafik Belarbi ◽  
Ameur El Amine Hamami ◽  
Alexandre Godin
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Storage Systems ◽  
Latent Heat Storage ◽  
Building Envelopes

Latent heat thermal energy storage systems incorporate phase change materials (PCMs) as storage materials. The high energy density of PCMs, their ability to store at nearly constant temperature, and the diversity of available materials make latent heat storage systems particularly competitive technologies for reducing energy consumption in buildings. This work reviews recent experimental and numerical studies on the integration of PCMs in building envelopes for passive energy storage. The results of the different studies show that the use of PCMs can reduce the peak temperature and smooth the thermal load. The integration of PCMs can be done on the entire building envelope (walls, roofs, windows). Despite many advances, some aspects remain to be studied, notably the long-term stability of buildings incorporating PCMs, the issues of moisture and mass transfer, and the consideration of the actual use of the building. Based on this review, we have identified possible contributions to improve the efficiency of passive systems incorporating PCMs. Thus, fatty acids and their eutectic mixtures, combined with natural insulators, such as vegetable fibers, were chosen to make shape-stabilized PCMs composites. These composites can be integrated in buildings as a passive thermal energy storage material.

scholarly journals Comparing water and paraffin PCM as storage mediums for thermal energy storage applications

2019 ◽  
Vol 116 ◽  
pp. 00057
Author(s):  
Christos Pagkalos ◽  
Michalis Gr. Vrachopoulos ◽  
John Konstantaras ◽  
Kostas Lymperis
Keyword(s):  
Energy Storage ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Storage ◽  
Heat Transfer Fluid ◽  
Computational Domain ◽  
Sensible Heat ◽  
Latent Heat Storage ◽  
Storage Mechanism

A CFD analysis is performed in two different heat storage mediums, water and paraffin phase change material (PCM), in order to evaluate and compare the two mediums for use in heating thermal energy storage (HTES) applications. The two mediums use different heat storing mechanisms, namely water uses Sensible Heat Storage, and the PCM Latent heat storage. The applied computational domain represents a single tube of a heat exchanger (HE), and so it comprises of a copper tube with aluminium fins. The geometric characteristics of the domain are taken in accordance with commercially used HE’s for HTES applications [1]. The characteristics studied are the stored energy of the system, the temperature of the heat transfer fluid (HTF) in the outlet and the temperature of the storage medium. The results of the simulations showed that for the same mass of storage mediums, the PCM can store more energy than water, for the same temperature of the HTF, as expected. Also, the temperature of the medium for the sensible heat storage rises linearly with the energy stored inside it, while in the latent heat storage mechanism, the temperature of the medium rises linearly till the melting (or solidification) of it, then stays almost steady until the melting of the whole volume and then rises again until it reaches the temperature of the HTF.

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