scholarly journals Optimization of Material Properties of Phase Change Materials for Latent Heat Thermal Energy Storage

MENDEL ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 47-54
Author(s):  
Michal Brezina ◽  
Lubomir Klimes ◽  
Josef Stetina

Nowadays, people are increasingly interested in renewable energy sources and accumulation of energy for its efficient use. The use of non-renewable resources is progressively decreasing due to their adverse changes in climate conditions and high production of CO2 emissions. This work deals with the problem of heat accumulation by means of the phase change of a material using the Stefan problem, which serves to describe the temperature distribution in the medium and to determine the location of the interface between the solid and liquid phase. This approach is used to determine desired properties and thermal behaviour of the material under different accumulation requirements. The main objective was to create and solve an optimization model in order to determine heat transfer conditions and other parameters to ensure the extrema of thermal behaviour characterization.

Author(s):  
Nancy González-Cervantes ◽  
Mercedes Salazar-Hernández ◽  
Miroslava Cano-Lara ◽  
Carmen Salazar-Hernández

Today, the effective renewable energy sources are research topics, with direct solar radiation being one of the best sources of energy. However, the use of this form of energy is optimized with the development of technologies for storage (TES). One of the proposed techniques for solar energy storage is the application of phase change materials (PCMs). Several candidates of phase change materials such as organic and inorganic and their mixtures have been proposed as energy storage because they have a high latent heat. However, a disadvantage of these materials is their decomposition during storage and energy release cycles, therefore, in this project it is proposed to encapsulate PCMs in mesoporous silica networks in order to increase thermal stability.


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2971
Author(s):  
Rok Koželj ◽  
Eneja Osterman ◽  
Fabrizio Leonforte ◽  
Claudio Del Pero ◽  
Alessandro Miglioli ◽  
...  

When considering the deployment of renewable energy sources in systems, the challenge of their utilization comes from their time instability when a mismatch between production and demand occurs. With the integration of thermal storages into systems that utilize renewable energy sources, such mismatch can be evened out. The use of phase-change materials (PCMs) as thermal storage has a theoretical advantage over the sensible one because of their high latent heat that is released or accumulated during the phase-change process. Therefore, the present paper is a review of latent thermal storages in hydronic systems for heating, cooling and domestic hot water in buildings. The work aims to offer an overview on applications of latent thermal storages coupled with heat pumps and solar collectors. The review shows that phase-change materials improve the release of heat from thermal storage and can supply heat or cold at a desired temperature level for longer time periods. The PCM review ends with the results from one of the Horizon2020 research projects, where indirect electrical storage in the form of thermal storage is considered. The review is a technological outline of the current state-of-the-art technology that could serve as a knowledge base for the practical implementation of latent thermal storages. The paper ends with an overview of energy storage maturity and the objectives from different roadmaps of European bodies.


2013 ◽  
Vol 687 ◽  
pp. 255-261 ◽  
Author(s):  
Sandra Cunha ◽  
José Barroso Aguiar ◽  
Victor Ferreira ◽  
António Tadeu

Increasingly in a society with a high growth rate and standards of comfort, the need to minimize the currently high energy consumption by taking advantage of renewable energy sources arises. The mortars with incorporation of phase change materials (PCM) have the ability to regulate the temperature inside buildings, contributing for an increase in the level of thermal comfort and reduction of the use of heating, ventilation and air conditioning (HVAC) equipment, using only the energy supplied by the sun. However, the incorporation of PCM in mortars modifies some of its characteristics. Therefore, the main objective of this study was the characterization of mortars doped with two different phase change materials. Specific properties of different PCM, such as particle size, shape and enthalpy were studied, as well as the properties of the fresh and hardened state of these mortars. Nine different compositions were developed which were initially doped with microcapsules of PCM A and subsequently doped with microcapsules of PCM B. It was possible to observe that the incorporation of phase change materials in mortars causes differences in properties such as compressive strength, flexural strength and shrinkage. After the study of the behaviour of these mortars with the incorporation of two different phase change materials, it was possible to select the composition with a better compromise between its aesthetic appearance, physical and mechanical characteristics.


2014 ◽  
pp. 13-17
Author(s):  
Zoltán Balla

The renewable energy sources could be used in energy production, while no or only very slightly emit harmful substances to the environment. The solar, wind, hydropower, biomass and heat rational utilization of land contributes to greenhouse gas emissions.Renewable energy sources also reduces the dependence on fossil fuels, thus contributing to increase security of supply. The creation of local jobs to strengthen the area's population retaining ability.


2021 ◽  
Vol 1 (1) ◽  
pp. 7-14
Author(s):  
Qudama M. Q. Al-Yasiri ◽  
Márta Szabó

Phase change materials (PCMs) are increasingly investigated in the last years as successful in many thermal energy storage applications. In the building sector, PCMs are utilised to improve building efficiency by reducing cooling/heating loads and promoting renewable energy sources, such as solar energy. This paper shows the recent research works on integrating PCMs with building envelope for heating purposes. The main PCM categories and their main characteristics are presented, focusing on PCM types applied for building heating applications. The main methods adopted to incorporate PCMs with building elements and materials are mentioned, and the popular passive and active incorporation techniques are discussed. Lastly, the main contribution to building energy saving is discussed in terms of heating applications. The analysed studies indicated that all PCMs could improve the building energy saving in the cold climates by up to 44.16% regardless of their types and techniques. Several conclusions and recommendations are derived from the analysed studies that are believed to be a guideline for further research.


2021 ◽  
Vol 4 (5(112)) ◽  
pp. 12-20
Author(s):  
Olga Khliyeva ◽  
Vitaly Zhelezny ◽  
Aleksey Paskal ◽  
Yana Hlek ◽  
Dmytro Ivchenko

Thermal energy storage (TES) plays an important role in solar heat power systems. The use of phase change materials (PCM) and selecting additives to increase the rate of heat accumulation is a promising way to increase the efficiency and reliability of such systems. The objects of the study were pure paraffin wax (PW) and composite PCMs based on it (containing aluminum and copper wool of 30 and 45 μm in diameter, respectively). An experimental setup with a cylindrical measuring cell was created, which was also considered as a model of a capsule with a thermal storage material. The rate of temperature change in the pure PW sample and samples of composite PCMs was experimentally measured. Two modes of heating and cooling were investigated: from 48 to 59 °C (mode with a phase change) and from 30 to 40 °C (mode without phase changes). Heating time from 48 to 59 °C for the PW sample was 13 min., for the PW samples with the content of aluminum wool of 0.00588 and 0.01780 m3·m-3 − 11 and 10.5 min., for the PW samples with the content of copper wool of 0.00524 and 0.01380 m3·m-3 − 11 and 8 min., correspondingly. The minimum heating time from 30 to 40 °C was 6 min. for the sample of PW with 0.01380 m3·m-3 of copper wool in comparison with 9 min. for the sample of pure PW. The expediency of using copper wool as an additive to thermal storage materials of PW to increase the charging and discharging rate of TES devices without significantly raising their price was confirmed. The presence of metal wool in molten PW suppresses bottom-up convective currents, so the main mechanism of heat transfer is thermal conductivity. This fact will contribute to a faster equalization of the temperature field by the height of heat storage capsules


2020 ◽  
Vol 10 (3) ◽  
pp. 5814-5818
Author(s):  
M. A. Aichouni ◽  
N. F. Alshammari ◽  
N. Ben Khedher ◽  
M. Aichouni

The intermittent nature of renewable energy sources such as solar and wind necessitates integration with energy-storage units to enable realistic applications. In this study, thermal performance enhancement of the finned Cylindrical Thermal Energy Storage (C-TES) with nano-enhanced Phase Change Material (PCM) integrated with the water heating system under Storage, Charging and Discharging (SCD) conditions were investigated experimentally. The effects of the addition of copper oxide (CuO) and aluminum oxide (Al2O3) nanoparticles in PCM on thermal conductivity, specific heat, and on charging and discharging performance rates were theoretically and experimentally investigated and studied in detail. The experimental apparatus utilized paraffin wax as PCM, which was filled in Finned C-TES to conduct the experiments. The experimental results showed a positive improvement compared with the non-nano additive PCM. The significance and originality of this project lies within the evaluation and identification of preferable metal-oxides with higher potential for improving thermal performance.


Author(s):  
Kristīne Šeļepova

Raksta mērķis ir apzināt atjaunojamo energoresursu tiesisko regulējumu, tā atbalsta shēmas un problemātiku. Raksta autore skaidro, vai šo tiesību aizsardzības līmenis ir pietiekams, vai ir pieņemtas nepieciešamās materiālo tiesību normas, kā arī vai ir pietiekoši tiesiskie līdzekļi, kas nodrošina šo tiesību aizsardzības ievērošanu, kā arī nākamos soļus energoresursu liberalizācijas posmos. Use of renewable energy increases independence from imported energy, reduces greenhouse gas emissions, as well as increases security of energy supply. However, energy industry concedes that power becomes more vulnerable because of historical paradigms; independent power base is replaced with production from renewable energy sources. This is due to subsidies in the investment priority being cost-effective renewable resources projects. Thus, it is necessary to develop a solution defining how volatile and unpredictable renewable energy sources integrated into the European electricity market can be, while ensuring safe and uninterrupted power supply.


2020 ◽  
Vol 170 ◽  
pp. 01007
Author(s):  
Marwa El Yassi ◽  
Ikram El Abbassi ◽  
Alexandre Pierre ◽  
Yannick Melinge

Nowadays, buildings sector contributes to climate change by consuming a considerable amount of energy to afford thermal comfort for occupants. Passive cooling techniques are a promising solution to increase the thermal inertia of building envelopes, and reduce temperature fluctuations. The phase change materials, known as PCM, can be efficiently employed to this purpose, because of their high energy storage density. Among the various existing solutions, the present study is dedicated to solid-liquid phase change materials. Temperature evolution (according to their defined temperature range) induces the chemical change of the material and its state. For building applications, the chemical transition can be accomplished from liquid to solid (solidification) and from solid to liquid (melting). In fact, this paper presents a comparative thermal analysis of several test rooms with and without phase change materials embedded in a composite wallboard in different climates. The used PCM consist in a flexible sheet of 5 mm thickness (Energain, manufactured by the company DuPont de Nemours). The main properties of such a commercial solution have been delivered by the manufacturer and from analyses. The room model was validated using laboratory instrumentations and measurements of a test room in four cities: Lyon; Reading and Casablanca. Results indicate that this phase change material board can absorb heat gains and also reduce the indoor air temperature fluctuations during daytime. The aim of the study is to show the benefits of this layer with phase change material and compare it in different climatic zones.


Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3523 ◽  
Author(s):  
Haichao Wang ◽  
Giulia Di Pietro ◽  
Xiaozhou Wu ◽  
Risto Lahdelma ◽  
Vittorio Verda ◽  
...  

Renewable energy sources (RES) are playing an increasingly important role in energy markets around the world. It is necessary to evaluate the benefits from a higher level of RES integration with respect to a more active cross-border transmission system. In particular, this paper focuses on the sustainable energy transitions for Finland and Italy, since they have two extreme climate conditions in Europe and quite different profiles in terms of energy production and demand. We developed a comprehensive energy system model using EnergyPLAN with hourly resolution for a reference year for both countries. The models include electricity, heat and transportation sectors. According to the current base models, new scenarios reflecting an RES increase in total fuel consumption have been proposed. The future shares of renewables are based on each nation’s potential. The outcomes of the new scenarios support the future national plans, showing how decarburization in an energy system can occur in relation to the European Roadmap 2030 and 2050. In addition, possible power transmission between Italy and Finland were investigated according to the vision of an integrated European energy system with more efficient cross-border activities.


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