Heat and cold storage with PCM

Transcription

1 Harald Mehling Luisa F. Cabeza Heat and cold storage with PCM An up to date introduction into basics and applications With 208 Figures and 28 Tables 4y Springer

2 Contents 1 Basic thermodynamics of thermal energy storage Methods for thermal energy storage Sensible heat Latent heat of solid-liquid phase change Latent heat of liquid-vapor phase change Heat of chemical reactions Potential applications of latent heat storage with solid-liquid phase change Temperature control Storage of heat or cold with high storage density References 9 2 Solid-liquid phase change materials Physical, technical, and economic requirements Classes of materials Overview Detailed discussion Typical material problems and possible solutions Phase separation solved by mixing, gelling, or thickening Subcooling and methods to reduce it Encapsulation to prevent leakage and improve heat transfer Mechanical stability and thermal conductivity improved by composite materials Mechanical stability Thermal conductivity Commercial PCM, PCM composite materials, and encapsulated PCM PCM :..; PCM composite materials PCM composite materials to improve handling and applicability PCM-graphite composites to increase the thermal conductivity Encapsulated PCM Examples of macroencapsulation Examples of microencapsulation References 52 3 Determination of physical and technical properties Definition of material and object properties Stored heat of materials 59

3 XII Contents Basics of calorimetry Problems in doing measurements on PCM Problems in presenting data on PCM Calorimeter types and working principles Differential scanning calorimetry in dynamic mode Differential scanning calorimetry in steps mode Differential scanning calorimetry with temperature modulation (m-dsc) T-History method Heat storage and heat release of PCM-objects Air and other gases as heat transfer medium Water and other liquids as heat transfer medium Mixing calorimeter Setup derived from power compensated DSC Thermal conductivity of materials Stationary methods Dynamic methods Cycling stability of PCM, PCM-composites, and PCM-objects Cycling stability with respect to the stored heat Cycling stability with respect to heat transfer Compatibility of PCM with other materials Corrosion of metals Migration of components in plastics References Heat transfer basics Analytical models dimensional semi-infinite PCM layer dimensional semi-infinite PCM layer with boundary effects Cylindrical and spherical geometry Layer with finite thickness Summary and conclusion for analytical models...; Numerical models dimensional PCM layer Inclusion of subcooling using the enthalpy method Relation between h(t) functions and phase diagrams Modellization using commercial software Comparison of simulated and experimental results dimensional PCM layer without subcooling dimensional PCM layer with subcooling Summary and conclusion References 135

4 Contents XIII 5 Design of latent heat storages Boundary conditions and basic design options Boundary conditions on a storage Basic design options Overview on storage types Storages with heat transfer on the storage surface Insulated environment Construction principle and typical performance Example Heat transfer calculation No insulation and good thermal contact between storage and demand Construction principle and typical performance Example Heat transfer calculation Storages with heat transfer on internal heat transfer surfaces Heat exchanger type Construction principle and typical performance Example Heat transfer calculation Further information Direct contact type Construction principle and typical performance Example Heat transfer calculation Further information Module type Construction principle and typical performance Examples Heat transfer calculation Further information Storages with heat transfer by exchanging the heat storage medium Slurry type Construction principle and typical performance Example Heat transfer calculation Further information Sensible liquid type Construction principle and typical performance Example Heat transfer calculation Further information References 177

5 XIV Contents 6 Integration of active storages into systems Integration goal Integration concepts General concepts Special examples Cascade storages Simulation and optimization of systems References Applications in transport and storage containers Basics Ideal cooling of an object in ambient air Ideal cooling of an insulated object in ambient air Ideal cooling of an insulated object with PCM in ambient air Real cooling of an insulated object with PCM in ambient air Examples Multi purpose transport boxes and containers Thermal management system Containers for food and beverages Medical applications Electronic equipment References Applications for the human body Basics Energy balance of the human body Potential of PCM Methods to apply the PCM Macroencapsulated PCM Microencapsulated PCM Composite materials Examples Pocket heater Vests for different applications Clothes and underwear Kidney belt Plumeaus and sleeping bags Shoe inlets Medical applications References Applications for heating and cooling in buildings Basics of space heating and cooling Human comfort requirements 218

6 Contents XV Heat production, transfer, and storage in buildings Potential of using PCM Potential of PCM for temperature control Potential of PCM for heat or cold storage with high storage density Natural and artificial heat and cold sources Space cooling Space heating Heat-transfer Heating or cooling from a surface Heating or cooling by supplying hot or cold air Examples for space cooling Building materials Gypsum plasterboards with microencapsulated paraffin Plaster with microencapsulated paraffin Concrete with microencapsulated paraffin Panels with shape-stabilized paraffin Building components Ceiling with PCM Blinds with PCM Active systems using air as heat transfer fluid Systems integrated into the ceiling Systems integrated into the wall Systems integrated into the floor Decentralized cooling and ventilation unit Systems integrated into a ventilation channel Active building materials and components using a liquid heat transfer fluid for heat rejection PCM-plaster with capillary sheets Cooling ceiling with PCM-plasterboard Storages with active heat supply and rejection using a liquid heat transfer fluid Heat exchanger and module type storages using artificial ice Heat exchanger and module type storages using other PCM than ice Direct contact type storage using artificial ice A Storages using natural ice and snow Direct contact systems using other PCM Slurry type storages using artificial ice Slurry type storages using other PCM than water / ice Alternative integration concepts Examples for space heating Solar wall 274

7 XVI Contents Daylighting element Floor heating systems Floor heating system with hot water Floor heating system with electrical heating Floor heating system using hot air Solar air heating and ventilation system Storage for heating with hot water Heat exchanger type approach Module type approach Direct contact type approach Slurry type approach Further information References Appendix Index 305