Corrigendum to “Intrinsic kinetics in local modelling of thermochemical heat storage systems” [Appl. Therm. Eng. 192 (2021) 116880]

Increasing energy prices make space heating more expensive every year in The Organisation for Economic Co-operation and Development (OECD) member countries. Thermochemical heat storage systems (THSS) can be used to reduce residential energy consumption for space heating and to control humidity. Utilizing compressed thermochemical pellets as heat storage materials is a way to increase volumetric energy storage capacity and to improve the performance of the THSS. In this work, expanded natural graphite (ENG), activated carbon (AC), strontium bromide, and magnesium sulphate were mixed in different mass ratios and compressed under applied pressures in a range of 0.77 to 5.2 kN⋅mm−2 to form composite pellets with a diameter of 12 and 25 mm, respectively, and a thickness from 1.5 to 25 mm. These pellets were characterized using thermogravimetric analysis and differential scanning calorimetry. Cyclic tests of hydration at 20 °C and dehydration at 85 °C were conducted to investigate changes in the surface morphology and the heat and mass transfer characteristics of the composite pellets. The permeability and thermal conductivity of the composite pellets were also measured. It was found that the structural stability of the pellets was enhanced by increasing the compression pressure. Utilizing AC and ENG in the composite mixture enhanced the porosity, thermal conductivity, and the permeability of the pellets.

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Optimal Design of Combined Two-Tank Latent and Metal Hydrides-Based Thermochemical Heat Storage Systems for High-Temperature Waste Heat Recovery

Energies ◽

10.3390/en13164216 ◽

2020 ◽

Vol 13 (16) ◽

pp. 4216 ◽

Cited By ~ 1

Author(s):

Serge Nyallang Nyamsi ◽

Mykhaylo Lototskyy ◽

Ivan Tolj

Keyword(s):

Energy Storage ◽

Melting Point ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Heat Storage ◽

Waste Heat ◽

Storage Systems ◽

Storage System ◽

Metal Hydrides ◽

Thermochemical Heat Storage

The integration of thermal energy storage systems (TES) in waste-heat recovery applications shows great potential for energy efficiency improvement. In this study, a 2D mathematical model is formulated to analyze the performance of a two-tank thermochemical heat storage system using metal hydrides pair (Mg2Ni/LaNi5), for high-temperature waste heat recovery. Moreover, the system integrates a phase change material (PCM) to store and restore the heat of reaction of LaNi5. The effects of key properties of the PCM on the dynamics of the heat storage system were analyzed. Then, the TES was optimized using a genetic algorithm-based multi-objective optimization tool (NSGA-II), to maximize the power density, the energy density and storage efficiency simultaneously. The results indicate that the melting point Tm and the effective thermal conductivity of the PCM greatly affect the energy storage density and power output. For the range of melting point Tm = 30–50 °C used in this study, it was shown that a PCM with Tm = 47–49 °C leads to a maximum heat storage performance. Indeed, at that melting point narrow range, the thermodynamic driving force of reaction between metal hydrides during the heat charging and discharging processes is almost equal. The increase in the effective thermal conductivity by the addition of graphite brings about a tradeoff between increasing power output and decreasing the energy storage density. Finally, the hysteresis behavior (the difference between the melting and freezing point) only negatively impacts energy storage and power density during the heat discharging process by up to 9%. This study paves the way for the selection of PCMs for such combined thermochemical-latent heat storage systems.

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The effect of CO2 on Ca(OH)2 and Mg(OH)2 thermochemical heat storage systems

Energy ◽

10.1016/j.energy.2017.02.034 ◽

2017 ◽

Vol 124 ◽

pp. 114-123 ◽

Cited By ~ 14

Author(s):

J. Yan ◽

C.Y. Zhao ◽

Z.H. Pan

Keyword(s):

Heat Storage ◽

Storage Systems ◽

Thermochemical Heat Storage

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Thermodynamic Efficiency of Water Vapor / Solid Chemical Sorption Heat Storage for Buildings: Theoretical Limits and Integration Considerations

10.20944/preprints201904.0079.v1 ◽

2019 ◽

Author(s):

Frédéric Kuznik

Keyword(s):

Energy Efficiency ◽

Water Vapor ◽

Heat Storage ◽

Storage Systems ◽

Thermodynamic Efficiency ◽

Reaction Enthalpy ◽

Available Energy ◽

Thermochemical Heat Storage ◽

Sorption Heat

The theoretical limits of water sorbate based chemical sorption heat storage are investigated in this study. First, a classification of \textit{thermochemical heat storage} is proposed based on bonding typology. Then, thermodynamics of chemical solid/gas sorption is introduced. The analysis of the reaction enthalpy from the literature indicates that this value is only slightly varying for one mole of water. Using this observation, and with the help of thermodynamical considerations, it is possible to derive conclusions on energy efficiency of closed and open heat storage systems. Whatever the salt, the main results are 1) the energy required for evaporation of water is, at least, 65% of the available energy of reaction and 2) the maximum theoretical energy efficiency of the system is about 1.8.

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