Dehydration kinetics and thermodynamics of magnesium chloride hexahydrate for thermal energy storage

2021 ◽  
Vol 219 ◽  
pp. 110819
Author(s):  
Jiaxing Xu ◽  
Tingxian Li ◽  
Taisen Yan ◽  
Jingwei Chao ◽  
Ruzhu Wang
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Magnesium Chloride ◽  
Dehydration Kinetics ◽  
Kinetics And Thermodynamics ◽  
Magnesium Chloride Hexahydrate ◽  
Chloride Hexahydrate

Numerical Comparison and Sizing of Sensible and Latent Thermal Energy Storage for Compressed Air Energy Storage Systems

2016 ◽  
Author(s):  
Mine Kaya ◽  
Ilker Tari ◽  
Derek K. Baker
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Magnesium Chloride ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Sensible Heat ◽  
Magnesium Chloride Hexahydrate ◽  
Chloride Hexahydrate

Compressed Air Energy Storage is a promising large-scale storage system in part because of its high power rating during discharge. But it is not the cleanest way of storing energy due to the necessity of an external heat source (typically the combustion of natural gas) to heat the air at the turbine inlet. This problem can be overcome with Thermal Energy Storage by storing the thermal energy of air at the compressor exhaust in order to be used for heating air before turbine. In this study, a numerical transient heat transfer model of Thermal Energy Storage is developed and the performance of Thermal Energy Storage is investigated based on heat storage capacity, required time to store unit amount of energy and air temperature profiles at the outlet of Thermal Energy Storage during discharge for the system. High heat storage per volume is necessary for more compact systems. Required time to store unit amount of energy is desired to be short for a fixed volume Thermal Energy Storage in order to maintain continuous operation; on the other hand, air at the outlet (turbine inlet) should be at a high temperature for the longest time possible to supply hot air to turbine. In order to investigate the effects of operating parameters, different volumes of Thermal Energy Storage tank filled with different storage mediums of various sizes are explored. Latent Heat and Sensible Heat Thermal Energy Storage systems are compared using magnesium chloride hexahydrate, paraffin, myristic acid and naphthalene as phase change materials and rock as sensible storage medium. Results show that Latent Heat Thermal Energy Storage gives a better performance than Sensible Heat Thermal Energy Storage. Among phase change materials, magnesium chloride hexahydrate provides the highest heat storage per volume. Required time to store unit amount of energy are comparable among the phase change materials. Magnesium chloride hexahydrate seems promising considering the discharge temperature profile at the Thermal Energy Storage outlet. Capsule size should be kept as small as possible which can be challenging in terms of manufacturing.

Solid/Liquid Phase Change Heat Transfer in Latent Heat Thermal Energy Storage

2009 ◽  
Author(s):  
D. Zhou ◽  
C. Y. Zhao
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Energy Storage ◽  
Phase Change ◽  
Calcium Chloride ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Metal Foams ◽  
Chloride Hexahydrate

Phase change materials (PCMs) have been widely used for thermal energy storage systems due to their capability of storing and releasing large amounts of energy with a small volume and a moderate temperature variation. Most PCMs suffer the common problem of low thermal conductivity, being around 0.2 and 0.5 for paraffin and inorganic salts, respectively, which prolongs the charging and discharging period. In an attempt to improve the thermal conductivity of phase change materials, the graphite or metallic matrix is often embedded within PCMs to enhance the heat transfer. This paper presents an experimental study on heat transfer characteristics of PCMs embedded with open-celled metal foams. In this study both paraffin wax and calcium chloride hexahydrate are employed as the heat storage media. The transient heat transfer behavior is measured. Compared to the results of pure PCMs samples, the investigation shows that the additions of metal foams can double the overall heat transfer rate during the melting process. The results of calcium chloride hexahydrate are also compared with those of paraffin wax.

scholarly journals Corrosion testing of metals in contact with calcium chloride hexahydrate used for thermal energy storage

2017 ◽  
Vol 68 (10) ◽  
pp. 1046-1056 ◽  
Author(s):  
S. J. Ren ◽  
J. Charles ◽  
X. C. Wang ◽  
F. X. Nie ◽  
C. Romero ◽  
...  
Keyword(s):  
Energy Storage ◽  
Calcium Chloride ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Corrosion Testing ◽  
Chloride Hexahydrate

Thermal Energy Discharge Characteristics of a PCM Heat Exchanger with Calcium Chloride Hexahydrate

2009 ◽  
Vol 79-82 ◽  
pp. 1815-1818 ◽  
Author(s):  
Xiao Qin Zhu ◽  
Jin Hu ◽  
Yu Fen Yang ◽  
Zhao Sheng Cao ◽  
Jian Sheng Lu ◽  
...  
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Calcium Chloride ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Main Body ◽  
Discharge Characteristics ◽  
Cold Air ◽  
Tube Heat Exchanger ◽  
Chloride Hexahydrate

Calcium chloride hexahydrate (CaCl2•6H2O) is an important inorganic phase change material used for thermal energy storage or discharge at lower storage temperature. Thermal energy discharge characteristics of a new type of PCM heat exchanger were investigated after thermal energy storage, in which its main body is based on the traditional structure of a shell-and-tube heat exchanger, and is full of PCMs (CaCl2•6H2O) in the tubes. The cold air of 16-17°C with different velocities flowed through the PCM heat exchanger, the temperature distributions of all the test points were measured by means of the experimetal system. The experimental results showed that, since the latent heat of phase transition in the tubes was so large during the process of thermal energy discharge, the time intervals of air temperature that maintained beyond 20°C at the outlet of the PCM heat exchanger were respectively 594min and 717min when the mass velocities of the cold air were 0.132 kg/s and 0.096kg/s, which is one of the important characteristics in the structure of this type of PCM heat exchanger. It can be used in the situations of temperature control or maintenance at the certain temperature, such as greenhouses, air conditioning etc.

scholarly journals Identification of best available thermal energy storage compounds for low-to-moderate temperature storage applications in buildings

2018 ◽  
Vol 68 (331) ◽  
pp. 160 ◽  
Author(s):  
J. Lizana ◽  
R. Chacartegui ◽  
A. Barrios-Padura ◽  
J. M. Valverde ◽  
C. Ortiz
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Energy Storage Materials ◽  
Storage Materials ◽  
Comparative Review ◽  
Chloride Hexahydrate ◽  
Salt Hydrates ◽  
Temperature Storage

Over the last 40 years different thermal energy storage materials have been investigated with the aim of enhancing energy efficiency in buildings, improving systems performance, and increasing the share of renewable energies. However, the main requirements for their efficient implementation are not fully met by most of them. This paper develops a comparative review of thermophysical properties of materials reported in the literature. The results show that the highest volumetric storage capacities for the best available sensible, latent and thermochemical storage materials are 250 MJ/m3, 514 MJ/m3 and 2000 MJ/m3, respectively, corresponding to water, barium hydroxide octahydrate, and magnesium chloride hexahydrate. A group of salt hydrates and inorganic eutectics have been identified as the most promising for the development of competitive thermal storage materials for cooling, heating and comfort applications in the short-term. In the long-term, thermochemical storage materials seem promising. However, additional research efforts are required.

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