High-Temperature Thermal Storage Systems Using Phase Change Materials

Luisa F. Cabeza, N.H. Steven Tay, Luisa Cabeza

• Publisher: Academic Press
• Year: 2017
• Print ISBN: 9780128053232
• eBook ISBN: 9780081009543
• Topic: Technology & Engineering
• Subtopic: Energy
• Index: Technology & Engineering

High-Temperature Thermal Storage Systems Using Phase Change Materials offers an overview of several high-temperature phase change material (PCM) thermal storage systems concepts, developed by several well-known global institutions with increasing interest in high temperature PCM applications such as solar cooling, waste heat and concentrated solar power (CSP). The book is uniquely arranged by concepts rather than categories, and includes advanced topics such as thermal storage material packaging, arrangement of flow bed, analysis of flow and heat transfer in the flow bed, energy storage analysis, storage volume sizing and applications in different temperature ranges.By comparing the varying approaches and results of different research centers and offering state-of-the-art concepts, the authors share new and advanced knowledge from researchers all over the world. This reference will be useful for researchers and academia interested in the concepts and applications and different techniques involved in high temperature PCM thermal storage systems.- Offers coverage of several high temperature PCM thermal storage systems concepts developed by several leading research institutions- Provides new and advanced knowledge from researchers all over the world- Includes a base of material properties throughout

Chapter 1

Introduction

Nguan H. Steven Tay¹, Martin Belusko², Ming Liu² and Frank Bruno³,    ¹Newcastle University Singapore, Singapore, Singapore,    ²University of South Australia, Adelaide, SA, Australia,    ³Research Professor, University of South Australia, Adelaide, SA, Australia

Abstract

This chapter gives a brief outline of thermal energy storage (TES) systems, which predominantly store heat as sensible heat in a substance. However, heat energy can be stored as latent energy during the change of phase of the storage material. This storage materials, known as phase change materials (PCMs) can store a greater amount of energy per unit volume than sensible heat storage systems. Details are given of TES uses in addressing the mismatch between the supply and demand of energy (particularly renewable energy) and also enables access to off-peak electricity tariffs offered during times of low electricity demand, and offers load shifting for the electricity grid. PCMs are also described in some detail. This is followed by a description of each of the following chapters in the book.

Keywords

Thermal energy storage system; phase change material; heat transfer enhancement

Contents

References 3

Thermal energy storage (TES) is the term used to describe the capture and storage of thermal energy for later use. The stored thermal energy may be used for a range of thermal processes including heating, cooling, refrigeration, and high-temperature applications. Of most significance, TES is useful for addressing the mismatch between the supply and the demand of energy, particularly relevant to renewable energy. It also enables access to off-peak electricity tariffs offered during times of low electricity demand and offers load shifting for the electricity grid [1].

Thermal energy storage systems predominantly store heat as sensible heat in a substance. However, during phase change heat energy can be stored as latent energy. Phase change material (PCM) thermal storage systems can store a greater amount of thermal energy per unit volume than sensible heat storage systems [1]. The solid–liquid phase change resulting in melting and solidification can store large amounts of heat or cold if a suitable material is selected [2]. What is perhaps the oldest form of latent energy storage is the harvesting of natural ice or snow from lakes, rivers, and mountains for food preservation, cold drinks, and space cooling. There are records of this practice dating back to 350 years ago [3]. More recently, research is being conducted for PCM TES in concentrated solar power plants [4].

Heat transfer enhancement is a critical component to achieving the full storage potential of PCM storage systems. Fundamentally, this involves reducing the thermal resistance between the PCM at the phase boundary and the heat transfer fluid (HTF) [5,6]. The majority of PCMs are made from low conducting materials. As a result, with the exception of metallic PCMs, one of the major problems of using PCMs in a TES is the low heat transfer of the PCM material. During a phase change process, the phase change starts at the heat transfer surface, causing the solid/liquid boundary of the PCM to move away from the heat transfer surface. This phase changed solid PCM acts as an insulator increasing the thermal resistance, thus reducing the heat transfer to the HTF. The heat transfer through the solid PCM is solely by conduction and due to its low thermal conductivity, the heat transfer rate within the PCM is low [7]. There are a number of traditional techniques that have been investigated to improve the heat transfer rate of PCMs used in thermal storage systems, including finned tubes of different configurations, insertion of a metal matrix into the PCM, using PCM dispersed with high conductivity particles and tube-in-tank [8]. There are also a number of additives that have been investigated to improve heat transfer rates. They include thin aluminum strips, thin wall rings made of steel, porous aluminum, porous graphite matrices, copper chips, and carbon fibers [9]. PCM composite with graphite or other high conducting materials has also been investigated [10]. Although effective, these methods add cost and reduce the storage density of the system. Other methods involve using PCM agitation which “moves” the PCM so that it is dynamic. With this process the resistance in the PCM is reduced and so the heat transfer is enhanced.

The focus of this book is on the application of PCMs for high-temperature thermal processes, particularly Concentrated Solar Power. Part 1 of this book focuses on novel heat transfer enhancement techniques involving dynamic methods developed by the University of South Australia (see Chapter 2: Direct Contact Phase Change Material Thermal Energy Storage and Chapter 3: Dynamic Concept at University of South Australia), German Aerospace Centre (see Chapter 4: Dynamic Concept at German Aerospace Centre) and Fraunhofer Institute of Solar Energy System (see Chapter 5: Dynamic Concept at Fraunhofer), and the applicability of these techniques at high temperature. The design and application of direct contact PCM TES system and dynamic PCM TES system for high temperature will first be discussed in Chapter 2, Direct Contact Phase Change Material Thermal Energy Storage, and Chapter 3, Dynamic Concept at University of South Australia, respectively. The design and development of PCMflux concept will then be presented in Chapter 4, Dynamic Concept at German Aerospace Centre, where a theoretical analysis and experimental investigation will be discussed. Finally, the concept and experimental demonstration of dynamic latent heat storage based on screw heat exchangers will be presented in Chapter 5, Dynamic Concept at Fraunhofer.

Part 2 of this book focuses on the application of PCMs at high temperature in which the PCM is static, and based on research conducted by the University of Lleida (see Chapter 6: Static Concept at University of Lleida) and University of South Australia (see Chapter 7: Static Concept at University of South Australia). Part 3 of this book focuses on the materials (see Chapter 8: Materials for Phase Change Material at High Temperature) and encapsulation (see Chapter 9: Encapsulation of High-Temperature Phase Change Materials) of PCM for high-temperature applications developed and analyzed by the University of South Australia. The last part of this book, part 4, analyzes the environmental approach of PCMs (see Chapter 10: Environmental Approach, conducted by University of Lleida and University of Antofagasta), and the economical approach of high-temperature storage systems (see Chapter 11: Economic Studies on High-Temperature Phase Change Storage Systems, conducted by University of South Australia).

Overall this book provides an overview for those interested in the latest research associated with using PCMs in high-temperature applications.

References

1. Dincer I, Rosen MA. Thermal energy storage: systems and applications Chichester: Wiley; 2002.

2. Mehling H, Cabeza LF. Heat and cold storage with PCM an up to date introduction into basics and applications Berlin: Springer-Verlag Berlin Heidelberg; 2008.

3. Paksoy HO, editor. Thermal energy storage for sustainable energy consumption [electronic resource]: fundamentals, case studies and design. Dordrecht: Springer; 2007.

4. Liu M, Steven Tay NH, Bell S, et al. Review on concentrating solar power plants and new developments in high temperature thermal energy storage technologies. Renew Sustain Energy Rev. 2016;1(53):1411–1432.

5. Belusko M, Halawa E, Bruno F. Characterising PCM thermal storage systems using the effectiveness-NTU approach. Int J Heat Mass Transf. 2012;55(13–14):3359–3365.

6. Tay NHS, Belusko M, Bruno F. An effectiveness-NTU technique for characterising tube-in-tank phase change thermal energy storage systems. Appl Energy. 2012;91(1):309–319.

7. Wang F, Maidment G, Missenden J, Tozer R. A review of research concerning the use of PCMS in air conditioning and refrigeration engineering. In: Anson M, Ko JM, Lam ESS, eds. Advances in building technology. Oxford: Elsevier; 2002;1273–1280.

8. Agyenim F, Eames P, Smyth M. Experimental study on the melting and solidification behaviour of a medium temperature phase change storage material (erythritol) system augmented with fins to power a LiBr/H₂O absorption cooling system. Renew Energy. 2011;36(1):108–117.

9. Hamada Y, Ohtsu W, Fukai J. Thermal response in thermal energy storage material around heat transfer tubes: effect of additives on heat transfer rates. Sol Energy. 2003;75(4):317–328.

10. Jegadheeswaran S, Pohekar SD. Performance enhancement in latent heat thermal storage system: a review. Renew Sustain Energy Rev. 2009;13(9):2225–2244.

Part I

Dynamic PCM Systems

Outline

Chapter 2 Direct Contact Phase Change Material Thermal Energy Storage

Chapter 3 Dynamic Concept at University of South Australia

Chapter 4 Dynamic Concept at German Aerospace Center

Chapter 5 Dynamic Concept at Fraunhofer

Chapter 2

Direct Contact Phase Change Material Thermal Energy Storage

Martin Belusko¹, Shane Sheoran¹ and Frank Bruno², ¹University of South Australia, Adelaide, SA, Australia, ²Research Professor, University of South Australia, Adelaide, SA, Australia

Abstract

This cha...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of Contributors
• Biographies
• Foreword
• Preface
• Chapter 1. Introduction
• Part I: Dynamic PCM Systems
• Part II: Static PCM Systems
• Part III: High Temperature Materials and Encapsulations
• Part IV: Environmental and Economic Approach
• Index