Thermal Energy Storage for Medium and High Temperatures: Concepts and Applications

Description

This book provides a descriptive classification of the various concepts, giving characteristic performance data and design fundamentals. Systems based on sensible heat storage, latent heat storage and thermo-chemical processes are presented, including the state of maturity and innovative solutions. Essential for the effective integration of thermal storage systems is the optimal adaption to the specific requirements of an application. This is shown in the second part, where storage solutions for conventional and solar thermal power plants are described. Further examples show the integration into batch processes, mobile applications or options to support the utilization of waste heat. Systems using thermal energy storage for facility scale storage of electricity are also described. Storage systems for medium and high temperatures are an emerging option to improve the energy efficiency of power plants and industrial facilities. Reflecting the wide area of applications in the temperature range from 100 °C to 1200 °C, a large number of storage concepts has been developed. Preface Contents Abbreviations Part I Concepts 1 Introduction 1.1 The Historical Development of Thermal Storage Systems for Medium and High Temperatures 1.2 Application Areas 1.3 Classification of Storage Concepts 1.4 Characterization and Assessment of Storage Systems 1.5 Economic Aspects References 2 Liquid Storage Media 2.1 Candidate Storage Fluids 2.2 Concepts for Liquid Storage Media 2.3 Two Tank Storage Systems 2.3.1 Thermal Oil Systems 2.3.2 Molten Salt Systems 2.3.2.1 Test Facilities 2.3.2.2 Storage Systems in Commercial Facilities 2.3.2.3 Economic Assessment 2.4 Research and Development 2.5 Molten Salts as Liquid Storage Media 2.5.1 Thermophysical Properties 2.5.1.1 Specific Heat 2.5.1.2 Density 2.5.1.3 Thermal Conductivity 2.5.1.4 Dynamic Viscosity 2.5.2 Thermal Stability 2.5.3 Corrosion Behavior 2.5.4 Safety Aspects 2.5.5 Environmental Aspects References 3 Solid Storage Media 3.1 Candidate Storage Materials 3.2 Concepts for Solid-State Storage Systems 3.3 Regenerator Type Storage Systems 3.3.1 Stacked Bricks 3.3.2 Packed Bed 3.3.3 Embedded Heat Exchanger 3.3.4 CellFlux 3.4 Active Storage Systems 3.5 Theoretical Analysis of Regenerator Type Solid Media Storage Systems 3.5.1 Physical Model 3.5.2 Governing Equations 3.5.3 Constitutive Equations 3.5.4 Analytical Solutions 3.5.5 Numerical Solutions References 4 Dual Media Storage 4.1 Types of Dual Media Storages 4.2 Pilot Scale Demonstration of Dual Media Storage Systems 4.3 Theoretical Analysis of Dual Media Storage 4.4 Outlook References 5 Steam Accumulators 5.1 Basic Types of Steam Accumulators 5.1.1 Sliding Pressure Accumulator (Ruths Storage) 5.1.2 Expansion Type Storage 5.1.3 Displacement Accumulator 5.2 Thermodynamics of Steam Accumulators 5.2.1 Sliding Pressure Accumulator 5.2.2 Approximate Solutions for the Sliding Pressure Steam Accumulator 5.2.3 Expansion Type Storage 5.3 Storage Vessels References 6 Latent Heat Energy Storage 6.1 Phase Change Materials 6.2 Concepts for Latent Heat Storage 6.2.1 Extended Heat Transfer Surface Concepts 6.2.1.1 Annular Fins 6.2.1.2 Longitudinal Fins 6.2.1.3 Parallel Plate Geometries 6.2.2 Encapsulation 6.2.2.1 Macroencapsulation 6.2.2.2 Microencapsulation 6.2.3 Intermediate Heat Transfer Fluid 6.2.4 Active Systems 6.3 Modeling of PCM Storage Systems References 7 Thermochemical Energy Storage 7.1 Reaction Systems for Thermochemical Energy Storage 7.1.1 Concentration/dilution Systems 7.1.2 Methane Reforming 7.1.3 Ammonia Synthesis/dissociation 7.1.4 Sulfur Based Systems 7.1.5 Hydroxides 7.1.6 Carbonates 7.1.7 Metal Hydride Systems 7.1.8 Redox Systems References 8 Selection of Storage Concepts 8.1 Operating Temperature Range 8.2 Working Medium 8.3 Technical Development Status 8.4 Other Criteria Part II Applications 9 Concentrating Solar Power Plants 9.1 CSP Systems 9.2 Storage for CSP 9.3 Research and Development Projects 9.4 Commercial CSP Facilities with Integrated Storage 9.5 Role of Thermal Storage for CSP Technology 9.6 Prospects of CSP with Integrated Thermal Storage References 10 Industrial Storage Applications 10.1 Basic Concepts for Improving Industrial Energy Efficiency Through Thermal Storage Systems 10.1.1 Supporting Waste Heat Integration 10.1.2 Increasing the Utilization Factor of Components 10.1.3 Support for Waste Heat Conversion 10.1.4 Integration of Renewable Energy 10.1.5 Increasing the Flexibility of Combined Heat and Power (CHP) Plants 10.1.6 Storage as Thermal Rectifier 10.2 Industrial Application Areas for Thermal Storage Systems 10.3 Examples for the Use of Storage Systems in Industry 10.3.1 Waste Heat Power Generation in the Cement Industry 10.3.2 Autoclaved Building Materials 10.4 Perspectives References 11 Systems for the Storage of Electrical Energy 11.1 State of the Art: Large-Scale Energy Storage 11.2 Basic Concepts for Electrical Energy Storage Based on Heat Storage 11.2.1 Power-To-Heat to Power (PHP) 11.2.2 Compressed Air Energy Storage (CAES) 11.2.2.1 Diabatic CAES 11.2.2.2 Adiabatic CAES 11.2.2.3 Isothermal CAES 11.2.3 Pumped Thermal Energy Storage (PTES) 11.2.3.1 PTES Based on Brayton Cycles 11.2.3.2 PTES Based on Rankine Cycles 11.2.4 Liquid Air Energy Storage (LAES) 11.3 Hybrid Concepts 11.4 Outlook References 12 Integration into Thermal Power Plants 12.1 Early Steam Power Plants 12.2 Modern Power Plants 12.3 Outlook References 13 Power to Heat Storage 13.1 Electrical Heat Storage for Space Heating 13.2 Electrothermal Storage for Process Heat References 14 Mobile Applications 14.1 Energy Supply for the Prime Mover in Vehicles 14.1.1 System Based on Steam Accumulators 14.1.2 Thermochemical Energy Storage: The Honigmann Locomotive 14.1.3 Stirling Systems for Road Vehicles 14.2 Thermal Management of Vehicles 14.3 Space Applications 14.4 Mobile Heat Storage for Heat Supply References Index