scholarly journals Obtainment and Characterization of Metal-Coated Polyethylene Granules as a Basis for the Development of Heat Storage Systems

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 218
Author(s):  
Volodymyr Moravskyi ◽  
Anastasiia Kucherenko ◽  
Marta Kuznetsova ◽  
Ludmila Dulebova ◽  
Emil Spišák
Keyword(s):  
Heat Storage ◽  
Storage Systems ◽  
Storage System ◽  
Polymer Surface ◽  
Copper Ion ◽  
Copper Coating ◽  
X Ray Diffraction ◽  
Heat Accumulator ◽  
Mechanism Of Interaction

The research studied the feasibility of using copper-coated polyethylene granules as a basis for creating efficient heat storage systems. A technology for imparting catalytic properties to a polymer surface by the joint processing of polymer granules and an activator metal in a ball mill with their subsequent metallization in a chemical reducing solution is proposed. The efficiency of copper-coating a polyethylene surface is shown to be largely determined by the activation stage and the assumption regarding the mechanism of interaction of the activator metal with the polymer surface is made. To obtain different amounts of metal on the polyethylene granules, it is proposed that the method of remetallization is used. It was established that the rate of copper ion reduction depends on the number of previous coatings and is determined by the area of interaction of the metal-coated granules with the chemical reducing solution. The obtained metal-coated polyethylene granules were characterized in terms of the viability of using it as a phase transition material for a heat storage system. Using the developed installation that simulates the heat accumulator operation, it was shown that the efficiency of using metal-coated polyethylene granules to create heat storage systems is higher. The copper coating deposited on the polyethylene granules was studied using scanning electron microscopy and X-ray diffraction analysis.

Solid Media Thermal Storage Development and Analysis of Modular Storage Operation Concepts for Parabolic Trough Power Plants

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Doerte Laing ◽  
Wolf-Dieter Steinmann ◽  
Michael Fiß ◽  
Rainer Tamme ◽  
Thomas Brand ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Power Plants ◽  
Heat Storage ◽  
Storage Systems ◽  
Storage System ◽  
Sensible Heat ◽  
Economic Optimization ◽  
Parabolic Trough ◽  
Solid Media ◽  
Exergetic Analysis

Cost-effective integrated storage systems are important components for the accelerated market penetration of solarthermal power plants. Besides extended utilization of the power block, the main benefits of storage systems are improved efficiency of components, and facilitated integration into the electrical grids. For parabolic trough power plants using synthetic oil as the heat transfer medium, the application of solid media sensible heat storage is an attractive option in terms of investment and maintenance costs. For commercial oil trough technology, a solid media sensible heat storage system was developed and tested. One focus of the project was the cost reduction of the heat exchanger; the second focus lies in the energetic and exergetic analysis of modular storage operation concepts, including a cost assessment of these concepts. The results show that technically there are various interesting ways to improve storage performance. However, these efforts do not improve the economical aspect. Therefore, the tube register with straight parallel tubes without additional structures to enhance heat transfer has been identified as the best option concerning manufacturing aspects and investment costs. The results of the energetic and exergetic analysis of modular storage integration and operation concepts show a significant potential for economic optimization. An increase of more than 100% in storage capacity or a reduction of more than a factor of 2 in storage size and therefore investment cost for the storage system was calculated. A complete economical analysis, including the additional costs for this concept on the solar field piping and control, still has to be performed.

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

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4216 ◽  
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.

scholarly journals Characterization of MgSO4 Hydrate for Thermochemical Seasonal Heat Storage

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
V. M. van Essen ◽  
H. A. Zondag ◽  
J. Cot Gores ◽  
L. P. J. Bleijendaal ◽  
M. Bakker ◽  
...  
Keyword(s):  
Water Vapor ◽  
Built Environment ◽  
Vapor Pressure ◽  
Atmospheric Pressure ◽  
Heat Storage ◽  
Storage System ◽  
Water Vapor Pressure ◽  
Salt Hydrates ◽  
Seasonal Heat

Water vapor sorption in salt hydrates is one of the most promising means for compact, low loss, and long-term storage of solar heat in the built environment. One of the most interesting salt hydrates for compact seasonal heat storage is magnesium sulfate heptahydrate (MgSO4⋅7H2O). This paper describes the characterization of MgSO4⋅7H2O to examine its suitability for application in a seasonal heat storage system for the built environment. Both charging (dehydration) and discharging (hydration) behaviors of the material were studied using thermogravimetric differential scanning calorimetry, X-ray diffraction, particle distribution measurements, and scanning electron microscope. The experimental results show that MgSO4⋅7H2O can be dehydrated at temperatures below 150°C, which can be reached by a medium temperature (vacuum tube) collector. Additionally, the material was able to store 2.2 GJ/m3, almost nine times more energy than can be stored in water as sensible heat. On the other hand, the experimental results indicate that the release of the stored heat is more difficult. The amount of water taken up and the energy released by the material turned out to be strongly dependent on the water vapor pressure, temperature, and the total system pressure. The results of this study indicate that the application of MgSO4⋅7H2O at atmospheric pressure is problematic for a heat storage system where heat is released above 40°C using a water vapor pressure of 1.3 kPa. However, first experiments performed in a closed system at low pressure indicate that a small amount of heat can be released at 50°C and a water vapor pressure of 1.3 kPa. If a heat storage system has to operate at atmospheric pressure, then the application of MgSO4⋅7H2O for seasonal heat storage is possible for space heating operating at 25°C and a water vapor pressure of 2.1 kPa.

Effect of Laser Surface Modification on the Crystallinity of Poly(L-Lactic Acid)

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Anubha Bhatla ◽  
Y. Lawrence Yao
Keyword(s):  
Lactic Acid ◽  
Polymer Surface ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
Laser Surface Modification ◽  
Third Harmonic ◽  
X Ray ◽  
Annealing Conditions ◽  
Kinetics Of

Crystallinity of semicrystalline polymers such as aliphatic homopolymer poly(L-lactic acid) (PLLA) affects their degradation and physical properties. In this paper, the effects of laser irradiation using the third harmonic of a Nd:YAG laser on the crystallinity, long-range order, and short-range conformations at the surface of PLLA films are investigated. The factors affecting the transformation are also studied. Detailed characterization of the effect of laser treatment is accomplished using microscopy, X-ray diffraction, and infrared spectroscopy. The cooling rates in the process and the spatial and temporal temperature profiles are numerically examined. The simulation results in conjunction with melting and crystallization kinetics of PLLA are used to understand the effect on sample crystallinity. The effects of laser fluence and annealing conditions on the crystallinity of the processed films are examined. Since degradation profiles depend on crystallinity, laser processing can potentially be used to achieve a modified spatially controlled polymer surface with promising applications such as controlled drug delivery.

Latent Heat Storage for Solar Steam Systems

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Wolf-Dieter Steinmann ◽  
Rainer Tamme
Keyword(s):  
Latent Heat ◽  
Power Plants ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Storage Systems ◽  
Storage System ◽  
Saturation Temperature ◽  
Steam Generation ◽  
Latent Heat Storage ◽  
Research Activities

Solar thermal systems, including direct steam generation in the absorbers, require isothermal energy storage systems. One option to fulfil this requirement is the application of phase change materials (PCMs) to absorb or release energy. The implementation of cost-effective storage systems demands the compensation of the low thermal heat conductivity that is characteristic for the candidate materials for PCM. Solar steam generation for power plants requires latent heat storage systems for a saturation temperature range between 200°C and 320°C. This paper describes the basic concepts investigated and first results of research activities aiming at the demonstration of a storage system using steam provided by parabolic trough collectors.

Advanced Thermal Energy Storage Technology for Parabolic Trough

Solar Energy ◽  
2003 ◽  
Author(s):  
Rainer Tamme ◽  
Doerte Laing ◽  
Wolf-Dieter Steinmann
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Heat Storage ◽  
Storage Systems ◽  
Storage System ◽  
Discharge Process ◽  
Sensible Heat ◽  
Parabolic Trough ◽  
Storage Unit ◽  
Solid Media

The availability of storage capacity plays an important role for the economic success of solar thermal power plants. For today’s parabolic trough power plants, sensible heat storage systems with operation temperatures between 300°C and 390°C can be used. A solid media sensible heat storage system is developed and will be tested in a parabolic trough test loop at PSA, Spain. A simulation tool for the analysis of the transient performance of solid media sensible heat storage systems has been implemented. The computed results show the influence of various parameters describing the storage system. While the effects of the storage material properties are limited, the selected geometry of the storage system is important. The evaluation of a storage system demands the analysis of the complete power plant and not only of the storage unit. Then the capacity of the system is defined by the electric work produced by the power plant, during a discharge process of the storage unit. The choice of the operation strategy for the storage system proves to be essential for the economic optimization.

scholarly journals Development and Characterization of Concrete/PCM/Diatomite Composites for Thermal Energy Storage in CSP/CST Applications

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4410
Author(s):  
Adio Miliozzi ◽  
Franco Dominici ◽  
Mauro Candelori ◽  
Elisabetta Veca ◽  
Raffaele Liberatore ◽  
...  
Keyword(s):  
Energy Storage ◽  
Energy Density ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Power Plants ◽  
Heat Storage ◽  
Low Cost ◽  
Renewable Energy Sources ◽  
Storage System

Thermal energy storage (TES) systems for concentrated solar power plants are essential for the convenience of renewable energy sources in terms of energy dispatchability, economical aspects and their larger use. TES systems based on the use of concrete have been demonstrated to possess good heat exchange characteristics, wide availability of the heat storage medium and low cost. Therefore, the purpose of this work was the development and characterization of a new concrete-based heat storage material containing a concrete mix capable of operating at medium–high temperatures with improved performance. In this work, a small amount of shape-stabilized phase change material (PCM) was included, thus developing a new material capable of storing energy both as sensible and latent heat. This material was therefore characterized thermally and mechanically and showed increased thermal properties such as stored energy density (up to +7%, with a temperature difference of 100 °C at an average operating temperature of 250 °C) when 5 wt% of PCM was added. By taking advantage of these characteristics, particularly the higher energy density, thermal energy storage systems that are more compact and economically feasible can be built to operate within a temperature range of approximately 150–350 °C with a reduction, compared to a concrete-only based thermal energy storage system, of approximately 7% for the required volume and cost.

Energy-Based Modeling of Alternative Energy Storage Systems for Hybrid Vehicles

2011 ◽  
Author(s):  
J. McDonough ◽  
K. Jebakumar ◽  
F. Chiara ◽  
M. Canova ◽  
K. Koprubasi
Keyword(s):  
Energy Storage ◽  
Fuel Economy ◽  
Alternative Energy ◽  
Storage Systems ◽  
Storage System ◽  
Energy Storage System ◽  
Hybrid Vehicles ◽  
Energy Storage Systems ◽  
Fuel Economy Improvement

Alternative energy storage systems (AESS) are receiving considerable interest today for low-cost mild-hybrid vehicles where the electrical system is substituted with mechanical or hydraulic energy storage. As these technologies are being explored, simulation tools become helpful to predict the behavior of the energy storage system during vehicle use, as well as to conduct comparative studies evaluating the energy and power density, fuel economy improvement, system weight and costs. This paper presents an energy-based modeling approach to characterize the low-frequency dynamic behavior of alternative energy storage systems for hybrid vehicle applications, with the ability to predict the energy flows and sources of energy loss during driving operations. The model aims at evaluating the potential, in terms of efficiency and fuel economy improvement, offered by non-electrified energy storage systems, such as mechanical (flywheels) or hydraulic (accumulators). The modeling tool developed is able to provide a characterization of the performance of each of the two systems starting from a characterization of the components energy conversion behavior. The paper includes a simulation study where the performance of a mechanical and hydraulic energy storage system are compared on a forward-oriented hybrid vehicle simulator, with the objective of characterizing and comparing the energy recuperation process and the energy efficiency of the two systems.

scholarly journals Cyclic mechanical stability of thermal energy storage media

2020 ◽  
Vol 205 ◽  
pp. 07008
Author(s):  
Henok Hailemariam ◽  
Frank Wuttke
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Storage ◽  
Mechanical Performance ◽  
Mechanical Stability ◽  
Storage Systems ◽  
Supply And Demand ◽  
Storage System ◽  
Industrial Applications

Closing the gap between supply and demand of energy is one of the biggest challenges of our era. In this aspect, thermal energy storage via borehole thermal energy storage (BTES) and sensible heat storage systems has recently emerged as a practical and encouraging alternative in satisfying the energy requirements of household and industrial applications. The majority of these heat energy storage systems are designed as part of the foundation or sub-structure of buildings with load bearing capabilities, hence their mechanical stability should be carefully studied prior to the design and operation phases of the heat storage system. In this study, the cyclic mechanical performance of a commercial cement-based porous heat storage material is analyzed under different amplitudes of cyclic loading and medium temperatures using a recently developed cyclic thermo-mechanical triaxial device. The results show a significant dependence of the cyclic mechanical behavior of the material, such as in the form of cyclic axial and accumulated plastic strains, on the different thermo-mechanical loading schemes.

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