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Author

Ramalingam Velraj

Other affiliations: College of Engineering, Guindy
Bio: Ramalingam Velraj is an academic researcher from Anna University. The author has contributed to research in topics: Thermal energy storage & Phase-change material. The author has an hindex of 41, co-authored 135 publications receiving 6724 citations. Previous affiliations of Ramalingam Velraj include College of Engineering, Guindy.


Papers
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TL;DR: In this article, the problems associated with the selection of a phase change material (PCM) and the various methods used to contain them for space heating and cooling applications are discussed.
Abstract: Efficient and economical technology that can be used to store large amounts of heat or cold in a definite volume is the subject of research for a long time. Thermal storage plays an important role in building energy conservation, which is greatly assisted by the incorporation of latent heat storage (LHS) in building products. LHS in a phase change material (PCM) is very attractive because of its high storage density with small temperature swing. It has been demonstrated that for the development of a latent heat storage system (LHTS) in a building fabric, the choice of the PCM plays an important role in addition to heat transfer mechanism in the PCM. Thermal energy storage in the walls, ceiling and floor of buildings may be enhanced by encapsulating or embedding suitable PCMs within these surfaces. They can either capture solar energy directly or thermal energy through natural convection. Increasing the thermal storage capacity of a building can increase human comfort by decreasing the frequency of internal air temperature swings so that the indoor air temperature is closer to the desired temperature for a longer period of time. This paper aims to gather the information from the earlier works on the developments of PCM's incorporation in building, the problems associated with the selection of PCM and the various methods used to contain them for space heating and cooling applications.

487 citations

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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

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TL;DR: In this paper, the thermal behavior of a packed bed of combined sensible and latent heat thermal energy storage (TES) unit with a constant temperature bath/solar collector is investigated.

357 citations

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TL;DR: In this paper, performance and emission analyses carried out in an unmodified diesel engine fueled with Pongamia pinnata methyl ester (PPME) and its blends with diesel.

315 citations

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TL;DR: In this paper, a shell and finned tube heat exchanger integrated with an IC engine setup to extract heat from the exhaust gas and a thermal energy storage tank used to store the excess energy available is investigated in detail.

278 citations


Cited by
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Journal ArticleDOI
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

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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

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1,682 citations

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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

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TL;DR: In this article, the authors summarized previous works on latent thermal energy storage in building applications, covering PCMs, the impregnation methods, current building applications and their thermal performance analyses, as well as numerical simulation of buildings with PCMs.

1,569 citations