Internal and external fin heat transfer enhancement technique for latent heat thermal energy storage in triplex tube heat exchangers
TL;DR: In this article, heat transfer enhancement technique by using internal and external fins for PCM melting in a triplex tube heat exchanger (TTHX) was investigated numerically.
About: This article is published in Applied Thermal Engineering.The article was published on 2013-04-29. It has received 350 citations till now. The article focuses on the topics: Heat transfer & Annular fin.
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TL;DR: In this paper, the authors present a review on various techniques of heat transfer enhancement in latent heat thermal energy storage (LHTES) systems, which can be achieved through either geometric configuration and/or thermal conductivity enhancement.
Abstract: This paper presents a state-of-the-art review on various techniques of heat transfer enhancement in latent heat thermal energy storage (LHTES) systems. Heat transfer enhancement in LHTES systems can be achieved through either geometric configuration and/or thermal conductivity enhancement. The use of extended surfaces such as fins or heat pipes is a common technique for heat transfer enhancement in LHTES systems and therefore, reviewed in details in this paper. Next, we studied the thermal conductivity enhancement techniques, which include the use of porous materials, nanoparticles with high thermal conductivity, and low-density materials. Finally, studies involving combined techniques for heat transfer enhancement are reviewed in the paper. The paper discusses research gaps in the methods of heat transfer enhancement for LHTES systems and proposed some recommendations.
403 citations
TL;DR: In this paper, the melting process in a triplex-tube heat exchanger with phase-change material (PCM) RT82.26 was numerically investigated using the Fluent 6.3.
363 citations
TL;DR: In this article, a comparative review of phase change material (PCM) based LHS performance enhancement methods is presented, which can be classified into three categories: using high thermal conductivity additives and porous media to enhance PCM thermal conductivities, using finned tubes and encapsulated PCMs to extend heat transfer surface, using multistage or cascaded LHS technique and thermodynamic optimization to improve the heat transfer uniformity.
Abstract: Latent heat storage (LHS) is considered as the most promising technique for thermal energy storage, due to its high energy storage density and nearly constant working temperature. However, the lower thermal conductivity of the phase change material (PCM) used in LHS system seriously weakens thermal energy charging and discharging rates. In order to improve the thermal performance of LHS system, a lot of research on performance enhancement have been carried out. This review paper will concern on the development of PCMs and performance enhancement methods for LHS system in the last decade. The available enhancement methods can be classified into three categories: using high thermal conductivity additives and porous media to enhance PCM thermal conductivity, using finned tubes and encapsulated PCMs to extend heat transfer surface, using multistage or cascaded LHS technique and thermodynamic optimization to improving the heat transfer uniformity. The comparative reviews on PCMs, corresponding performance enhancement methods and their characteristics are presented in present paper. That will help in selecting reliable PCMs and matching suitable performance enhancement method to achieve the best thermal performance for PCM based LHS system. In addition, the research gaps in performance enhancement techniques for LHS systems are also discussed and some recommendations for future research are proposed.
327 citations
TL;DR: In this paper, the augmentation in heat transfer for a shell and tube type LHSU is estimated by carrying out experimental analysis with three longitudinal fins installed on the heat transfer fluid (HTF) tube.
302 citations
TL;DR: In this paper, phase change materials (PCMs) can be applied to several different solar energy systems for the extended heat energy storage which is quite useful as the solar energy is intermittent in nature and is unavailable during the night period.
Abstract: Phase change materials (PCMs) can be applied to several different solar energy systems for the extended heat energy storage which is quite useful as the solar energy is intermittent in nature and is unavailable during the night period Application of PCMs in solar energy systems allows the solar energy to be used at any time even in the absence of the natural solar radiation Thus, the use of PCMs in the solar energy systems can bridge the demand and supply gap of the normal electrical energy This paper deals with the recent advances in PCMs application in different solar energy systems and presents almost all of the emerging areas where the applications of PCM in solar energy systems are urgently required The novel and most recent developments of PCMs in solar thermal energy systems, such as, solar thermal power plants, solar air heater, solar water heater and solar cooker have been duly covered Furthermore, the application of PCMs in heating and cooling of buildings have been presented as well as the investigation of the PCM application in the solar photovoltaic systems for the performance enhancement of PCMs Intrinsically important, from the study it has been found that PCMs have been in use in almost all of the solar energy systems even though their uses are still limited and commercially not available due to several economic and environmental constraints Thus, the paper attempts to present recent and novel approaches by the authors around the world on PCMs applications in the solar energy in well documented forms Based on the findings, future recommendations have also been given to provide the idea and pragmatic concepts for the researcher to work on the areas of research for further improvements in the systems
290 citations
References
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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
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
TL;DR: In this article, the melting of pure gallium in a rectangular cavity has been numerically investigated using the enthalpy-porosity approach for modeling combined convection-diffusion phase change.
Abstract: The melting of pure gallium in a rectangular cavity has been numerically investigated using the enthalpy-porosity approach for modeling combined convection-diffusion phase change. The major advantage of this technique is that it allows a fixed-grid solution of the coupled momentum and energy equations to be undertaken without resorting to variable transformations. In this work, a two-dimensional dynamic model is used and the influence of laminar natural-convection flow on the melting process is considered. Excellent agreement exists between the numerical predictions and experimental results available in the literature. The enthalpy-porosity approach has been found to converge rapidly, and is capable of producing accurate results for both the position and morphology of the melt front at different times with relatively modest computational requirements. These results may be taken to be a sound validation of this technique for modeling isothermal phase changes in metallurgical systems.
1,377 citations
TL;DR: In this paper, various heat transfer enhancement methods for latent heat thermal storage (LHTS) systems are discussed and three different experiments to augment heat transfer were conducted and the findings are reported.
483 citations
TL;DR: In this paper, an experimental energy storage system has been designed using a horizontal concentric tube heat exchanger incorporating a medium temperature phase change material (PCM) Erythritol, with a melting point of 117.7°C.
456 citations
"Internal and external fin heat tran..." refers background in this paper
...[26] studied the heat transfer enhancement by using different fin configurations (control PCM system, circular fin PCM system, and longitudinal fin PCM system) to improve the heat transfer of the PCM....
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