Thermal conductivity and latent heat thermal energy storage characteristics of paraffin/expanded graphite composite as phase change material
TL;DR: In this paper, the authors determined the proper amount of paraffin ( n -docosane) absorbed into expanded graphite (EG) to obtain form-stable composite as phase change material (PCM), examination of the influence of EG addition on the thermal conductivity using transient hot-wire method and investigation of latent heat thermal energy storage (LHTES) characteristics of Paraffin such as melting time, melting temperature and latent heat capacity using differential scanning calorimetry (DSC) technique.
About: This article is published in Applied Thermal Engineering.The article was published on 2007-06-01. It has received 793 citations till now. The article focuses on the topics: Liquid paraffin & Phase-change material.
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TL;DR: All carbon aerogels with ultralow density and temperature-invariant super-elasticity are fabricated by facile assembling of commercial carbon nanotubes and chemically-converted giant graphene sheets, on the basis of the synergistic effect between elastic CNTs ribs and giant graphene cell walls.
Abstract: All carbon aerogels (up to 1000 cm(3)) with ultralow density (down to 0.16 mg cm(-3)) and temperature-invariant (-190-900 °C) super-elasticity are fabricated by facile assembling of commercial carbon nanotubes (CNTs) and chemically-converted giant graphene sheets, on the basis of the synergistic effect between elastic CNTs ribs and giant graphene cell walls.
1,680 citations
TL;DR: In this article, the different storage concepts are reviewed and classified, and modellization of such systems is reviewed, and all materials considered in literature or plants are listed. But only a few plants in the world have tested high temperature thermal energy storage systems.
Abstract: Concentrated solar thermal power generation is becoming a very attractive renewable energy production system among all the different renewable options, as it has have a better potential for dispatchability. This dispatchability is inevitably linked with an efficient and cost-effective thermal storage system. Thus, of all components, thermal storage is a key one. However, it is also one of the less developed. Only a few plants in the world have tested high temperature thermal energy storage systems. In this paper, the different storage concepts are reviewed and classified. All materials considered in literature or plants are listed. And finally, modellization of such systems is reviewed.
1,445 citations
TL;DR: In this article, the state of the art of phase change materials for thermal energy storage applications is reviewed and an insight into recent efforts to develop new phase change material with enhanced performance and safety.
1,399 citations
TL;DR: In this article, the authors provide a review of solar collectors and thermal energy storage systems, including both non-concentrating collectors and concentrating collectors, in terms of optical optimisation, heat loss reduction, heat recuperation enhancement and different sun-tracking mechanisms.
1,370 citations
TL;DR: A review of experimental/computational studies to enhance the thermal conductivity of phase change materials (PCM) that were conducted over many decades is presented in this paper, where the authors focus on studies that concern with positioning of fixed, stationary high conductivity inserts/structures.
Abstract: A review of experimental/computational studies to enhance the thermal conductivity of phase change materials (PCM) that were conducted over many decades is presented. Thermal management of electronics for aeronautics and space exploration appears to be the original intended application, with later extension to storage of thermal energy for solar thermal applications. The present review will focus on studies that concern with positioning of fixed, stationary high conductivity inserts/structures. Copper, aluminum, nickel, stainless steel and carbon fiber in various forms (fins, honeycomb, wool, brush, etc.) were generally utilized as the materials of the thermal conductivity promoters. The reviewed research studies covered a variety of PCM, operating conditions, heat exchange and thermal energy storage arrangements. The energy storage vessels included isolated thermal storage units (rectangular boxes, cylindrical and annular tubes and spheres) and containers that transferred heat to a moving fluid medium passing through it. A few studies have focused on the marked role of flow regimes that are formed due to the presence of thermally unstable fluid layers that in turn give rise to greater convective mixing and thus expedited melting of PCM. In general, it can be stated that due to utilization of fixed high conductivity inserts/structures, the conducting pathways linking the hot and cold ends must be minimized.
1,028 citations
References
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TL;DR: In this paper, a review of the history of thermal energy storage with solid-liquid phase change has been carried out and three aspects have been the focus of this review: materials, heat transfer and applications.
4,019 citations
TL;DR: In this article, the melting and freezing behavior of various heat-of-fusion storage materials is investigated using the techniques of Thermal Analysis and Differential Scanning Calorimetry.
1,455 citations
TL;DR: In this article, the development of available thermal energy storage (TES) technologies and their individual pros and cons for space and water heating applications are reviewed and compared for low temperature applications, where water is used as a storage medium.
1,156 citations
TL;DR: The use of a latent heat storage system using Phase Change Materials (PCM) is an effective way of storing thermal energy (solar energy, off-peak electricity, industrial waste heat) and has the advantages of high storage density and the isothermal nature of the storage process as discussed by the authors.
Abstract: The use of a latent heat storage system using Phase Change Materials (PCM) is an effective way of storing thermal energy (solar energy, off-peak electricity, industrial waste heat) and has the advantages of high storage density and the isothermal nature of the storage process. It has been demonstrated that, for the development of a latent heat storage system, choice of the PCM plays an important role in addition to heat transfer mechanism. The information on the latent heat storage materials and systems is enormous and published widely in the literatures. In this paper, we make an effort to gather the information from the previous works on PCMs and latent heat storage systems. This review will help to find a suitable PCM for various purposes a suitable heat exchanger with ways to enhance the heat transfer, and it will also help to provide a variety of designs to store the heat using PCMs for different applications, i.e. space heating & cooling, solar cooking, greenhouses, solar water heating and waste heat recovery systems. Measurement techniques of thermophysical properties, studies on thermal cycles for long term stability, corrosion of the PCMs and enhancement of heat transfer in PCM are discussed. New PCM innovations are also included for the awareness of new applications. This paper contains a list of about 250 PCMs and more than 250 references.
638 citations
"Thermal conductivity and latent hea..." refers background or methods in this paper
...24 W/m K for solid paraffin [8,12–14]....
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...Several inorganic and organic PCMs and their mixtures have been investigated as LHTES materials [8–13]....
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...24 W/m K) is its major drawback decreasing the rates of heat stored and released during melting and crystallization processes which in turn limits their utility areas [8,12–14]....
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...Among the investigated PCMs, paraffins have been widely used for LHTES applications due to their large latent heat and proper thermal characteristics such as little or no super cooling, low vapor pressure, good thermal and chemical stability, and self-nucleating behavior [8,12–15]....
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TL;DR: In this article, a supported phase change material (PCM) made of paraffin impregnated by capillary forces in a compressed expansed natural graphite (CENG) matrix is presented.
560 citations
"Thermal conductivity and latent hea..." refers background or methods in this paper
...reported that the paraffin with melting temperatures of 73– 80 C was loaded to the compressed expanded natural graphite (CENG) from 65 to 95 wt% depending on the bulk density of CENG [24]....
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...: 73–80 C)/compressed expanded natural graphite (CENG) as a high and power thermal storage material and they determined the relationship between the thermal conductivity of the composite and the bulk density of CENG [24]....
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...This was attributed to high thermal conductivity of the EG [24,25,29]....
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