Numerical and experimental study on the solidification of PCM around a vertical axially finned isothermal cylinder
TL;DR: In this paper, the authors presented the results of a numerical and experimental investigation realized on finned tubes with the objective of using them in thermal storage systems, based upon the pure conduction mechanism of heat transfer, the enthalpy formulation approach and the control volume method.
About: This article is published in Applied Thermal Engineering.The article was published on 2001-01-01. It has received 387 citations till now. The article focuses on the topics: Annular fin & Fin.
Citations
More filters
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
Additional excerpts
...[146] use finned tubes in thermal storage systems....
[...]
TL;DR: In this paper, a review of the phase change materials (PCM) and their application in energy storage is presented, where the main advantages of encapsulation are providing large heat transfer area, reduction of the PCMs reactivity towards the outside environment and controlling the changes in volume of the storage materials as phase change occurs.
2,636 citations
Cites background from "Numerical and experimental study on..."
...They, as well as others [64–66] have tested the idea of using finned tubes in which the PCM was placed between the fins....
[...]
...[66] have also studied heat transfer enhancement by using axial fins on the external tube immersed vertically in a PCM....
[...]
TL;DR: In this paper, the phase change problem has been formulated using pure conduction approach but the problem has moved to a different level of complexity with added convection in the melt being accounted for, which makes it difficult for comparison to be made to assess the suitability of PCMs to particular applications.
Abstract: This paper reviews the development of latent heat thermal energy storage systems studied detailing various phase change materials (PCMs) investigated over the last three decades, the heat transfer and enhancement techniques employed in PCMs to effectively charge and discharge latent heat energy and the formulation of the phase change problem. It also examines the geometry and configurations of PCM containers and a series of numerical and experimental tests undertaken to assess the effects of parameters such as the inlet temperature and the mass flow rate of the heat transfer fluid (HTF). It is concluded that most of the phase change problems have been carried out at temperature ranges between 0 °C and 60 °C suitable for domestic heating applications. In terms of problem formulation, the common approach has been the use of enthalpy formulation. Heat transfer in the phase change problem was previously formulated using pure conduction approach but the problem has moved to a different level of complexity with added convection in the melt being accounted for. There is no standard method (such as British Standards or EU standards) developed to test for PCMs, making it difficult for comparison to be made to assess the suitability of PCMs to particular applications. A unified platform such as British Standards, EU standards needs to be developed to ensure same or similar procedure and analysis (performance curves) to allow comparison and knowledge gained from one test to be applied to another.
1,630 citations
Cites background from "Numerical and experimental study on..."
...Commercial paraffin wax [94] 52....
[...]
...Paraffin RT60/RT58 [93,94] 55 to 60 214....
[...]
...Several studies have been conducted to study heat transfer enhancement techniques in phase change materials (PCMs) and include finned tubes of different configurations [59,69,94,97,98, 102,109–112], bubble agitation [112], insertion of a metal matrix into the PCM [113,114], using PCM dispersed with high conductivity particles [115], micro-encapsulation of the PCM [116,117] or shell and tube (multitubes) [99,118]....
[...]
TL;DR: In this paper, the state of the art of phase change materials (PCMs) for storing solar energy is discussed. But, prior to the large-scale practical application of this technology, it is necessary to resolve numerous problems at the research and development stage.
Abstract: The continuous increase in the level of greenhouse gas emissions and the climb in fuel prices are the main driving forces behind efforts to more effectively utilise various sources of renewable energy. In many parts of the world, direct solar radiation is considered to be one of the most prospective sources of energy. However, the large-scale utilisation of this form of energy is possible only if the effective technology for its storage can be developed with acceptable capital and running costs. One of prospective techniques of storing solar energy is the application of phase change materials (PCMs). Unfortunately, prior to the large-scale practical application of this technology, it is necessary to resolve numerous problems at the research and development stage. This paper looks at the current state of research in this particular field, with the main focus being on the assessment of the thermal properties of various PCMs, methods of heat transfer enhancement and design configurations of heat storage facilities to be used as a part of solar passive and active space heating systems, greenhouses and solar cooking.
1,173 citations
Cites background or methods from "Numerical and experimental study on..."
...The influence of finned structures on the process of melting and solidification of PCMs was investigated in [73–84] and works by Velraj et al....
[...]
...[83] studied theoretically and experimentally the solidification process around a vertical tube with longitudinal fins and a heat carrier flowing inside the tube....
[...]
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.
793 citations
Cites methods from "Numerical and experimental study on..."
...conductivity problem of paraffins as PCMs, studies have been carried out with the purpose of developing LHTES systems with unfinned and finned configurations [16–19], dispersing high conductivity particles [20] and inserting a metal matrix into paraffin wax [21]....
[...]
References
More filters
Book•
01 Jan 1980
TL;DR: In this article, the authors focus on heat and mass transfer, fluid flow, chemical reaction, and other related processes that occur in engineering equipment, the natural environment, and living organisms.
Abstract: This book focuses on heat and mass transfer, fluid flow, chemical reaction, and other related processes that occur in engineering equipment, the natural environment, and living organisms. Using simple algebra and elementary calculus, the author develops numerical methods for predicting these processes mainly based on physical considerations. Through this approach, readers will develop a deeper understanding of the underlying physical aspects of heat transfer and fluid flow as well as improve their ability to analyze and interpret computed results.
21,858 citations
1,508 citations
1,419 citations
TL;DR: A three-time level implicit scheme, which is unconditionally stable and convergent, is employed for the numerical solution of phase change problems, on the basis of an analytical approach consisting in the approximation of the latent heat effect by a large heat capacity over a small temperature range as discussed by the authors.
500 citations
TL;DR: An implicit scheme for one dimensional problems, based upon the above development, is described which can cope with any size phase change temperature range and the influence of internal heating, simultaneously.
486 citations