scholarly journals The Impact of Active and Passive Thermal Management on the Energy Storage Efficiency of Metal Hydride Pairs Based Heat Storage

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3006
Author(s):  
Serge Nyallang Nyamsi ◽  
Ivan Tolj
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Thermal Management ◽  
Metal Hydride ◽  
Heat Storage ◽  
Energy Storage Density ◽  
Storage Efficiency ◽  
Transfer Enhancement ◽  
Storage Density ◽  
Energy Storage Efficiency

Two-tank metal hydride pairs have gained tremendous interest in thermal energy storage systems for concentrating solar power plants or industrial waste heat recovery. Generally, the system’s performance depends on selecting and matching the metal hydride pairs and the thermal management adopted. In this study, the 2D mathematical modeling used to investigate the heat storage system’s performance under different thermal management techniques, including active and passive heat transfer techniques, is analyzed and discussed in detail. The change in the energy storage density, the specific power output, and the energy storage efficiency is studied under different heat transfer measures applied to the two tanks. The results showed that there is a trade-off between the energy storage density and the energy storage efficiency. The adoption of active heat transfer enhancement (convective heat transfer enhancement) leads to a high energy storage density of 670 MJ m−3 (close to the maximum theoretical value of 755.3 MJ m−3). In contrast, the energy storage efficiency decreases dramatically due to the increase in the pumping power. On the other hand, passive heat transfer techniques using the bed’s thermal conductivity enhancers provide a balance between the energy storage density (578 MJ m−3) and the energy efficiency (74%). The utilization of phase change material as an internal heat recovery medium leads to a further reduction in the heat storage performance indicators (142 MJ m−3 and 49%). Nevertheless, such a system combining thermochemical and latent heat storage, if properly optimized, can be promising for thermal energy storage applications.

An effective approach to achieve high energy storage density and efficiency in BNT-based ceramics by doping AgNbO3

2019 ◽  
Vol 48 (48) ◽  
pp. 17864-17873 ◽  
Author(s):  
Hua Wang ◽  
Xiaoli Jiang ◽  
Xiaoqin Liu ◽  
Ruonan Yang ◽  
Yang Yang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Energy Storage ◽  
High Energy ◽  
Frequency Stability ◽  
Energy Storage Density ◽  
Storage Efficiency ◽  
Storage Density ◽  
Energy Storage Efficiency ◽  
High Energy Storage Density ◽  
High Energy Storage

The BNBLT–0.01AN ceramic with the highest energy storage density (Ws) value of ∼1.697 J cm−3 and energy storage efficiency (η) of ∼82.3% exhibits optimal thermal stability and frequency stability.

scholarly journals Improved Energy Storage Performance of All-Organic Composite Dielectric via Constructing Sandwich Structure

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1972
Author(s):  
Mengjia Feng ◽  
Tiandong Zhang ◽  
Chunhui Song ◽  
Changhai Zhang ◽  
Yue Zhang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Sandwich Structure ◽  
Volume Ratio ◽  
High Energy ◽  
Energy Storage Density ◽  
Storage Efficiency ◽  
Storage Density ◽  
Energy Storage Efficiency ◽  
High Dielectric ◽  
High Energy Storage

Improving the energy storage density of dielectrics without sacrificing charge-discharge energy storage efficiency and reliability is crucial to the performance improvement of modern electrical and electronic systems, but traditional methods of doping high-dielectric ceramics cannot achieve high energy storage densities without sacrificing reliability and storage efficiency. Here, an all-organic energy storage dielectric composed of ferroelectric and linear polymer with a sandwich structure is proposed and successfully prepared by the electrostatic spinning method. Additionally, the effect of the ferroelectric/linear volume ratio on the dielectric properties, breakdown, and energy storage is systematically studied. The results show that the structure has good energy storage characteristics with a high energy storage density (9.7 J/cm3) and a high energy storage efficiency (78%). In addition, the energy storage density of the composite dielectric under high energy storage efficiency (90%) is effectively improved (25%). This result provides theoretical analysis and experience for the preparation of multilayer energy storage dielectrics which will promote the development and application of energy storage dielectrics.

scholarly journals Performance of compressed air energy storage system with regenerative heat exchangers

2020 ◽  
Vol 194 ◽  
pp. 01028
Author(s):  
Shibiao Wang ◽  
Wei Liang ◽  
Xi Lai ◽  
Wenqiang Sun
Keyword(s):  
Energy Storage ◽  
Heat Exchangers ◽  
Storage System ◽  
Energy Storage System ◽  
Energy Storage Density ◽  
Storage Efficiency ◽  
Ratio Distribution ◽  
Regenerative Heat ◽  
Storage Density ◽  
Energy Storage Efficiency

In order to improve the heat storage and heat exchange system of advanced adiabatic compressed air energy storage (AA-CAES) system, an AA-CAES system with regenerative heat exchangers (RHEs) is studied. The RHE is used to replace the conventional complex units, including heat exchangers, high temperature tank, and low temperature tank mode. For the AA-CAES with RHEs, the energy storage system is simplified to reduce the heat loss in the heat exchange and storage processes, and thus, the output work, energy storage density, energy storage efficiency of the system are improved. The thermodynamic model is established and the influences of compression ratio distribution, expansion ratio distribution and ambient temperature on the system performance are investigated. The results show that for the AA-CAES with RHEs, when the ratio of compression ratios is 1.14, the input work of the compressor is the minimum, the energy storage efficiency is 66.42%, and the energy storage density is 3.61 kWh/m3. When the ratio of expansion ratios is 0.82, the energy storage efficiency reaches the maximum value of 67.38%, and the energy storage density reaches the maximum value of 3.66 kWh/m3.

scholarly journals Low-Cost High Energy Density Material for Solar Thermal Heat Storage

2020 ◽  
Vol 3 (2) ◽  
pp. 46-56
Author(s):  
Rebhi Damseh
Keyword(s):  
Thermal Conductivity ◽  
Energy Storage ◽  
Energy Density ◽  
Heat Storage ◽  
Low Cost ◽  
High Energy ◽  
Solar Thermal ◽  
Energy Storage Density ◽  
Solar Thermal Energy ◽  
Storage Density

A low-cost and enhanced thermal properties composite material for sensible heat storage in solar thermal energy storage applications is introduced. The proposed material is produced primarily for small scale solar thermal applications. However, it can be utilized for large scale solar thermal plants. The material has the advantages of high thermal conductivity and large energy storage density. The introduced material is composed of a mixture of cement and cast-iron particles. To obtain an optimal mixture, different samples of the material are prepared with different ratios of the cement-iron weights. The thermal conductivity of the produced samples is measured by using the linear heat conduction method. The specific heat capacity of the produced mixtures is calculated by using the Rule of the mixture. The obtained results show that the introduced material has a significant enhancement in thermal conductivity. Where, thermal conductivity as high as ~6.0 W/m.K and energy storage density as high as ~788 Joule/cm3 are achieved. The estimated volume energy density is ~89% higher than that of water. The produced material has the advantage of high energy volume density, being unhazardous, chemically stable, eco-friendly, easy to fabricate, and integrate with solar thermal energy systems and is a low-cost material.

Nano-ZnO decorated ZnSnO3 as efficient fillers in PVDF matrixes: toward simultaneous enhancement of energy storage density and efficiency and improved energy harvesting activity

Nanoscale ◽  
2020 ◽  
Vol 12 (40) ◽  
pp. 20908-20921
Author(s):  
Abhishek Sasmal ◽  
Samar Kumar Medda ◽  
P. Sujatha Devi ◽  
Shrabanee Sen
Keyword(s):  
Energy Storage ◽  
Dielectric Loss ◽  
Energy Harvesting ◽  
Dielectric Permittivity ◽  
Electrical Energy ◽  
Energy Storage Density ◽  
Storage Efficiency ◽  
Storage Density ◽  
Electrical Energy Storage ◽  
And Storage

Along with enhanced dielectric permittivity and suppressed dielectric loss, PVDF-ZnO@ZnSnO3 films showed simultaneous enhancement in electrical energy storage density and storage efficiency compared to PVDF-ZnSnO3 composites.

Giant energy storage efficiency and high recoverable energy storage density achieved in K0.5Na0.5NbO3-Bi(Zn0.5Zr0.5)O3 ceramics

2020 ◽  
Vol 8 (26) ◽  
pp. 8777-8785 ◽  
Author(s):  
Miao Zhang ◽  
Haibo Yang ◽  
Da Li ◽  
Liang Ma ◽  
Ying Lin
Keyword(s):  
Energy Storage ◽  
Power Systems ◽  
Pulsed Power ◽  
Energy Storage Density ◽  
Storage Efficiency ◽  
Promising Candidate ◽  
Environmental Friendliness ◽  
Large Dielectric Constant ◽  
Energy Storage Efficiency ◽  
Recoverable Energy

K0.5Na0.5NbO3 (KNN)-based ceramics, as promising candidate materials that could replace lead-based ceramics, exhibit outstanding potential in pulsed power systems due to their large dielectric constant, high Curie temperature and environmental friendliness.

scholarly journals A Comparative Study of High-Temperature Latent Heat Storage Systems

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6886
Author(s):  
Alok Kumar Ray ◽  
Dibakar Rakshit ◽  
K. Ravi Kumar ◽  
Hal Gurgenci
Keyword(s):  
Heat Flux ◽  
High Temperature ◽  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Heat Storage ◽  
Energy Storage Density ◽  
Latent Heat Storage ◽  
Storage Density ◽  
Ultra High Temperature

High-temperature latent heat storage (LHS) systems using a high-temperature phase change medium (PCM) could be a potential solution for providing dispatchable energy from concentrated solar power (CSP) systems and for storing surplus energy from photovoltaic and wind power. In addition, ultra-high-temperature (>900 oC) latent heat storage (LHS) can provide significant energy storage density and can convert thermal energy to both heat and electric power efficiently. In this context, a 2D heat transfer analysis is performed to capture the thermo-fluidic behavior during melting and solidification of ultra-high-temperature silicon in rectangular domains for different aspect ratios (AR) and heat flux. Fixed domain effective heat capacity formulation has been deployed to numerically model the phase change process using the finite element method (FEM)-based COMSOL Multiphysics. The influence of orientation of geometry and heat flux magnitude on charging and discharge performance has been evaluated. The charging efficiency of the silicon domain is found to decrease with the increase in heat flux. The charging performance of the silicon domain is compared with high-temperature LHS domain containing state of the art salt-based PCM (NaNO3) for aspect ratio (AR) = 1. The charging rate of the NaNO3 domain is observed to be significantly higher compared to the silicon domain of AR = 1, despite having lower thermal diffusivity. However, energy storage density (J/kg) and energy storage rate (J/kgs) for the silicon domain are 1.83 and 2 times more than they are for the NaNO3 domain, respectively, after 3.5 h. An unconventional counterclockwise circular flow is observed in molten silicon, whereas a clockwise circular flow is observed in molten NaNO3 during charging. The present study establishes silicon as a potential PCM for designing an ultra-high-temperature LHS system.

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