Phase Change Material
Encyclopedia
A phase-change material (PCM) is a substance with a high heat of fusion which, melting and solidifying at a certain temperature, is capable of storing and releasing large amounts of energy. Heat is absorbed or released when the material changes from solid to liquid and vice versa; thus, PCMs are classified as latent heat
storage (LHS) units.
Initially, the solid–liquid PCMs behave like sensible heat
storage (SHS) materials; their temperature rises as they absorb heat. Unlike conventional SHS, however, when PCMs reach the temperature at which they change phase (their melting temperature) they absorb large amounts of heat at an almost constant temperature. The PCM continues to absorb heat without a significant rise in temperature until all the material is transformed to the liquid phase. When the ambient temperature around a liquid material falls, the PCM solidifies, releasing its stored latent heat. A large number of PCMs are available in any required temperature range from −5 up to 190 oC. Within the human comfort range of 20° to 30°C, some PCMs are very effective. They store 5 to 14 times more heat per unit volume than conventional storage materials such as water, masonry or rock.
s (CH3(CH2)2nCOOH)
Whilst this process liberates a small quantity of energy, large surfaces area allows significant (1–2 °C) heating or cooling in buildings. The corresponding materials are wool insulation, earth/clay render finishes, etc.
Volumetric heat capacity
(VHC) J·m−3·K−1
Thermal Inertia (I) = Thermal effusivity (e) J·m−2·K−1·s−1/2
s, fatty acid
s and ester
s, and various paraffin
s (such as octadecane). Recently also ionic liquid
s were investigated as novel PCMs.
As most of the organic solutions are water-free, they can be exposed to air, but all salt based PCM solutions must be encapsulated to prevent water evaporation or uptake. Both types offer certain advantages and disadvantages and if they are correctly applied some of the disadvantages becomes an advantage for certain applications.
They have been used since the late 1800s as a medium for the thermal storage applications. They have been used in such diverse applications as refrigerated transportation for rail and road applications and their physical properties are, therefore, well known.
Unlike the ice storage system, however, the PCM systems can be used with any conventional water chiller
both for a new or alternatively retrofit application. The positive temperature phase change allows centrifugal and absorption chillers as well as the conventional reciprocating and screw chiller systems or even lower ambient conditions utilizing a cooling tower
or dry cooler for charging the TES system.
The temperature range offered by the PCM technology provides a new horizon for the building services and refrigeration engineers regarding medium and high temperature energy storage applications. The scope of this thermal energy application is wide ranging of solar heating, hot water, heating rejection, i.e. cooling tower and dry cooler circuitry thermal energy storage applications.
Since PCMs transform between solid–liquid in thermal cycling, encapsulation naturally become the obvious storage choice.
As phase change materials perform best in small containers, therefore they are usually divided in cells. The cells are shallow to reduce static head – based on the principle of shallow container geometry. The packaging material should conduct heat well; and it should be durable enough to withstand frequent changes in the storage material's volume as phase changes occur. It should also restrict the passage of water through the walls, so the materials will not dry out (or water-out, if the material is hygroscopic). Packaging must also resist leakage and corrosion
. Common packaging materials showing chemical compatibility with room temperature PCMs include stainless steel
, polypropylene
and polyolefin
.
Thermal conductivity is a common property which is targeted for maximisation by creating thermal composites. In this case the basic idea is to increase thermal conductivity by adding a highly conducting solid (such as the copper-mesh) into the relatively low conducting PCM thus increasing overall or bulk (thermal) conductivity. If the PCM is required to flow, the solid must be porous, such as a mesh.
Solid composites such as fibre-glass or kevlar-pre-preg for the aerospace industry usually refer to a fibre (the kevlar or the glass) and a matrix (the glue which solidifies to hold fibres and provide compressive strength). A thermal composite is not so clearly defined, but could similarly refer to a matrix (solid) and the PCM which is of course usually liquid and/or solid depending on conditions.
Latent heat
Latent heat is the heat released or absorbed by a chemical substance or a thermodynamic system during a process that occurs without a change in temperature. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. The term was...
storage (LHS) units.
Characteristics and classification
PCMs latent heat storage can be achieved through solid–solid, solid–liquid, solid–gas and liquid–gas phase change. However, the only phase change used for PCMs is the solid–liquid change. Liquid-gas phase changes are not practical for use as thermal storage due to the large volumes or high pressures required to store the materials when in their gas phase. Liquid–gas transitions do have a higher heat of transformation than solid–liquid transitions. Solid–solid phase changes are typically very slow and have a rather low heat of transformation.Initially, the solid–liquid PCMs behave like sensible heat
Sensible heat
Sensible heat is the energy exchanged by a thermodynamic system that has as its sole effect a change of temperature.The term is used in contrast to a latent heat, which is the amount of energy exchanged that is hidden, meaning it cannot be observed as a change of temperature...
storage (SHS) materials; their temperature rises as they absorb heat. Unlike conventional SHS, however, when PCMs reach the temperature at which they change phase (their melting temperature) they absorb large amounts of heat at an almost constant temperature. The PCM continues to absorb heat without a significant rise in temperature until all the material is transformed to the liquid phase. When the ambient temperature around a liquid material falls, the PCM solidifies, releasing its stored latent heat. A large number of PCMs are available in any required temperature range from −5 up to 190 oC. Within the human comfort range of 20° to 30°C, some PCMs are very effective. They store 5 to 14 times more heat per unit volume than conventional storage materials such as water, masonry or rock.
Organic PCMs
Paraffin (CnH2n+2) and fatty acidFatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
s (CH3(CH2)2nCOOH)
- Advantages
- Freeze without much supercooling
- Ability to melt congruently
- Self nucleating properties
- Compatibility with conventional material of construction
- No segregation
- Chemically stable
- High heat of fusion
- Safe and non-reactive
- Recyclable
- Disadvantages
- Low thermal conductivity in their solid state. High heat transfer rates are required during the freezing cycle
- Volumetric latent heat storage capacity is low
- Flammable. This can be easily alleviated by a proper container
- To obtain reliable phase change points, most manufacturers use technical grade paraffins which are essentially paraffin mixture(s) and are completely refined of oil, resulting in high costs
Inorganic
Salt hydrates (MnH2O)- Advantages
- High volumetric latent heat storage capacity
- Availability and low cost
- Sharp melting point
- High thermal conductivity
- High heat of fusion
- Non-flammable
- Disadvantages
- Change of volume is very high
- Super cooling is major problem in solid–liquid transition
- Nucleating agents are needed and they often become inoperative after repeated cycling
Eutectics
Organic-organic, organic-inorganic, inorganic-inorganic compounds- Advantages
- Eutectics have sharp melting point similar to pure substance
- Volumetric storage density is slightly above organic compounds
- Disadvantages
- Only limited data is available on thermo-physical properties as the use of these materials are very new to thermal storage application
Hygroscopic materials
Many natural building materials are hygroscopic, that is they can absorb (water condenses) and release water (water evaporates). The process is thus:- Condensation (gas to liquid) ΔH<0; enthalpy decreases (exothermic process) gives off heat.
- Vaporization (liquid to gas) ΔH>0; enthalpy increases (endothermic process) absorbs heat (or cools).
Whilst this process liberates a small quantity of energy, large surfaces area allows significant (1–2 °C) heating or cooling in buildings. The corresponding materials are wool insulation, earth/clay render finishes, etc.
Selection criteria
- Thermodynamic properties. The phase change material should possess:
- Melting temperature in the desired operating temperatureOperating temperatureAn operating temperature is the temperature at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the device function and application context, and ranges from the minimum operating temperature to the...
range - High latent heat of fusion per unit volume
- High specific heat, high density and high thermal conductivity
- Small volume changes on phase transformation and small vapor pressure at operating temperatures to reduce the containment problem
- Congruent melting
- Melting temperature in the desired operating temperature
- Kinetic properties
- High nucleation rate to avoid supercooling of the liquid phase
- High rate of crystal growth, so that the system can meet demands of heat recovery from the storage system
- Chemical properties
- Chemical stability
- Complete reversible freeze/melt cycle
- No degradation after a large number of freeze/melt cycle
- Non-corrosiveness, non-toxic, non-flammable and non-explosive materials
- Economic properties
- Low cost
- Availability
Thermophysical properties of selected PCMs
| Material | Organic PCM |
Melting point Melting point The melting point of a solid is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at standard atmospheric pressure... oC Celsius Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death... |
Heat of fusion Enthalpy of fusion The enthalpy of fusion is the change in enthalpy resulting from heating one mole of a substance to change its state from a solid to a liquid. The temperature at which this occurs is the melting point.... kJ·kg Kilogram The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water... −1 |
Heat of fusion Enthalpy of fusion The enthalpy of fusion is the change in enthalpy resulting from heating one mole of a substance to change its state from a solid to a liquid. The temperature at which this occurs is the melting point.... MJ·m−3 |
cp solid kJ·kg−1·K−1 |
cp liquid kJ·kg−1·K−1 |
ρ Density The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight... solid kg·m−3 |
ρ Density The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight... liquid kg·m−3 |
k solid W Watt The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:... ·m Metre The metre , symbol m, is the base unit of length in the International System of Units . Originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole , its definition has been periodically refined to reflect growing knowledge of metrology... −1·K Kelvin The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all... −1 |
VHC Volumetric heat capacity Volumetric heat capacity , also termed volume-specific heat capacity, describes the ability of a given volume of a substance to store internal energy while undergoing a given temperature change, but without undergoing a phase change... solid kJ·m−3 Cubic metre The cubic metre is the SI derived unit of volume. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère... ·K−1 |
VHC Volumetric heat capacity Volumetric heat capacity , also termed volume-specific heat capacity, describes the ability of a given volume of a substance to store internal energy while undergoing a given temperature change, but without undergoing a phase change... liquid kJ·m−3·K−1 |
e solid J Joule The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second... ·m−2 Square metre The square metre or square meter is the SI derived unit of area, with symbol m2 . It is defined as the area of a square whose sides measure exactly one metre... ·K−1·s Second The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock.... −1/2 |
Cost USD·kg−1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water | 0 | 917 | 1,000 | 1.6-2.22 | 4,186 | ||||||||
| Lauric acid Lauric acid Lauric acid , the saturated fatty acid with a 12-carbon atom chain, is a white, powdery solid with a faint odor of bay oil or soap.-Occurrence:... |
1,007 | 862 | ? | ? | |||||||||
| TME Trimethylolethane Trimethylolethane is the organic compound with the formula CH3C3. This colorless solid is a triol, that is it contains three hydroxy functional groups. More specifically, it features three primary alcohol groups in a compact neopentyl structure. Its esters are known for their resistance to heat,... (63%w/w)+H2O(37%w/w) |
1,120 | 1,090 | ? | ? | ? | ||||||||
| Mn(NO3)2·6H2O+MnCl2 Manganese(II) chloride Manganese chloride describes a series of compounds with the formula MnCl2x, where the value of x can be 0, 2, or 4. The tetrahydrate is the most common form of "manganese chloride". MnCl2·4H2O, but the anhydrous form and dihydrate MnCl2·2H2O are also known... ·4H2O(4%w/w) |
2015–25 | 1,795 | 1,728 | ? | ? | ? | |||||||
| Na2SiO3 Sodium silicate Sodium silicate is the common name for a compound sodium metasilicate, Na2SiO3, also known as water glass or liquid glass. It is available in aqueous solution and in solid form and is used in cements, passive fire protection, refractories, textile and lumber processing, and automobiles... ·5H2O |
48 | 1,450 | 1,280 | 0.103−0.128 | |||||||||
| Aluminium Aluminium Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances.... |
? | 2,700 | 2,375 | 237 | ? | ||||||||
| Copper Copper Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish... |
? | 8,940 | 8,020 | 401 | ? | ||||||||
| Gold Gold Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a... |
? | 19,300 | 17,310 | 318 | ? | ||||||||
| Iron Iron Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust... |
1,538 | ? | 7,874 | 6,980 | ? | ||||||||
| Lead Lead Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed... |
? | 11,340 | 10,660 | ? | |||||||||
| Lithium Lithium Lithium is a soft, silver-white metal that belongs to the alkali metal group of chemical elements. It is represented by the symbol Li, and it has the atomic number 3. Under standard conditions it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly... |
? | 534 | 512 | ? | |||||||||
| Silver Silver Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal... |
? | 10,490 | 9,320 | 429 | ? | ||||||||
| Titanium Titanium Titanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color.... |
1,668 | ? | 4,506 | 4,110 | ? | ||||||||
| Zinc Zinc Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2... |
? | 7,140 | 6,570 | 116 | ? |
Volumetric heat capacity
Volumetric heat capacity
Volumetric heat capacity , also termed volume-specific heat capacity, describes the ability of a given volume of a substance to store internal energy while undergoing a given temperature change, but without undergoing a phase change...
(VHC) J·m−3·K−1
Thermal Inertia (I) = Thermal effusivity (e) J·m−2·K−1·s−1/2
Technology, development and encapsulation
The most commonly used PCMs are salt hydrateHydrate
Hydrate is a term used in inorganic chemistry and organic chemistry to indicate that a substance contains water. The chemical state of the water varies widely between hydrates, some of which were so labeled before their chemical structure was understood....
s, fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
s and ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
s, and various paraffin
Paraffin
In chemistry, paraffin is a term that can be used synonymously with "alkane", indicating hydrocarbons with the general formula CnH2n+2. Paraffin wax refers to a mixture of alkanes that falls within the 20 ≤ n ≤ 40 range; they are found in the solid state at room temperature and begin to enter the...
s (such as octadecane). Recently also ionic liquid
Ionic liquid
An ionic liquid is a salt in the liquid state. In some contexts, the term has been restricted to salts whose melting point is below some arbitrary temperature, such as . While ordinary liquids such as water and gasoline are predominantly made of electrically neutral molecules, ILs are largely made...
s were investigated as novel PCMs.
As most of the organic solutions are water-free, they can be exposed to air, but all salt based PCM solutions must be encapsulated to prevent water evaporation or uptake. Both types offer certain advantages and disadvantages and if they are correctly applied some of the disadvantages becomes an advantage for certain applications.
They have been used since the late 1800s as a medium for the thermal storage applications. They have been used in such diverse applications as refrigerated transportation for rail and road applications and their physical properties are, therefore, well known.
Unlike the ice storage system, however, the PCM systems can be used with any conventional water chiller
Chiller
A chiller is a machine that removes heat from a liquid via a vapor-compression or absorption refrigeration cycle. This liquid can then be circulated through a heat exchanger to cool air or equipment as required.-Use in air conditioning:...
both for a new or alternatively retrofit application. The positive temperature phase change allows centrifugal and absorption chillers as well as the conventional reciprocating and screw chiller systems or even lower ambient conditions utilizing a cooling tower
Cooling tower
Cooling towers are heat removal devices used to transfer process waste heat to the atmosphere. Cooling towers may either use the evaporation of water to remove process heat and cool the working fluid to near the wet-bulb air temperature or in the case of closed circuit dry cooling towers rely...
or dry cooler for charging the TES system.
The temperature range offered by the PCM technology provides a new horizon for the building services and refrigeration engineers regarding medium and high temperature energy storage applications. The scope of this thermal energy application is wide ranging of solar heating, hot water, heating rejection, i.e. cooling tower and dry cooler circuitry thermal energy storage applications.
Since PCMs transform between solid–liquid in thermal cycling, encapsulation naturally become the obvious storage choice.
- Encapsulation of PCMs
- Macro-encapsulation: Early development of macro-encapsulation with large volume containment failed due to the poor thermal conductivityThermal conductivityIn physics, thermal conductivity, k, is the property of a material's ability to conduct heat. It appears primarily in Fourier's Law for heat conduction....
of most PCMs. PCMs tend to solidify at the edges of the containers preventing effective heat transfer. - Micro-encapsulation: Micro-encapsulationMicro-encapsulationMicro-encapsulation is a process in which tiny particles or droplets are surrounded by a coating to give small capsules many useful properties. In a relatively simplistic form, a microcapsule is a small sphere with a uniform wall around it...
on the other hand showed no such problem. It allows the PCMs to be incorporated into construction materials, such as concreteConcreteConcrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
, easily and economically. Micro-encapsulated PCMs also provide a portable heat storage system. By coating a microscopic sized PCM with a protective coating, the particles can be suspendedSuspension (chemistry)In chemistry, a suspension is a heterogeneous fluid containing solid particles that are sufficiently large for sedimentation. Usually they must be larger than 1 micrometer. The internal phase is dispersed throughout the external phase through mechanical agitation, with the use of certain...
within a continuous phase such as water. This system can be considered a phase change slurrySlurryA slurry is, in general, a thick suspension of solids in a liquid.-Examples of slurries:Examples of slurries include:* Lahars* A mixture of water and cement to form concrete* A mixture of water, gelling agent, and oxidizers used as an explosive...
(PCS). - Molecular-encapsulation is another technology, developed by Dupont de Nemours that allows a very high concentration of PCM within a polymer compound. It allows storage capacity up to 515 kJ/m2Square metreThe square metre or square meter is the SI derived unit of area, with symbol m2 . It is defined as the area of a square whose sides measure exactly one metre...
for a 5 mmMillimetreThe millimetre is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length....
board (103 MJ/m3Cubic metreThe cubic metre is the SI derived unit of volume. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère...
). Molecular-encapsulation allows drilling and cutting through the material without any PCM leakage.
- Macro-encapsulation: Early development of macro-encapsulation with large volume containment failed due to the poor thermal conductivity
As phase change materials perform best in small containers, therefore they are usually divided in cells. The cells are shallow to reduce static head – based on the principle of shallow container geometry. The packaging material should conduct heat well; and it should be durable enough to withstand frequent changes in the storage material's volume as phase changes occur. It should also restrict the passage of water through the walls, so the materials will not dry out (or water-out, if the material is hygroscopic). Packaging must also resist leakage and corrosion
Corrosion
Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...
. Common packaging materials showing chemical compatibility with room temperature PCMs include stainless steel
Stainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
, polypropylene
Polypropylene
Polypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...
and polyolefin
Polyolefin
A polyolefin is a polymer produced from a simple olefin as a monomer. For example, polyethylene is the polyolefin produced by polymerizing the olefin ethylene. An equivalent term is polyalkene; this is a more modern term, although polyolefin is still used in the petrochemical industry...
.
Thermal composites
Thermal-composites is a term given to combinations of phase change materials (PCMs) and other (usually solid) structures. A simple example is a copper-mesh immersed in a paraffin-wax. The copper-mesh within parraffin-wax can be considered a composite material, dubbed a thermal-composite. Such hybrid materials are created to achieve specific overall or bulk properties.Thermal conductivity is a common property which is targeted for maximisation by creating thermal composites. In this case the basic idea is to increase thermal conductivity by adding a highly conducting solid (such as the copper-mesh) into the relatively low conducting PCM thus increasing overall or bulk (thermal) conductivity. If the PCM is required to flow, the solid must be porous, such as a mesh.
Solid composites such as fibre-glass or kevlar-pre-preg for the aerospace industry usually refer to a fibre (the kevlar or the glass) and a matrix (the glue which solidifies to hold fibres and provide compressive strength). A thermal composite is not so clearly defined, but could similarly refer to a matrix (solid) and the PCM which is of course usually liquid and/or solid depending on conditions.
Applications
Applications of phase change materials include, but are not limited to:- Thermal energy storageThermal energy storageThermal energy storage comprises a number of technologies that store thermal energy in energy storage reservoirs for later use. They can be employed to balance energy demand between day time and night time. The thermal reservoir may be maintained at a temperature above or below that of the...
- Conditioning of buildingsHVACHVAC refers to technology of indoor or automotive environmental comfort. HVAC system design is a major subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer...
, such as 'ice-storage' - Cooling of heat and electrical engines
- Cooling: food, beverages, coffee, wine, milk products, green houses
- Medical applications: transportation of blood, operating tables, hot-cold therapies
- Waste heatWaste heatWaste heat sometimes called Secondary heat or Low-grade heat refers to heat produced by machines, electrical equipment and industrial processes for which no useful application is found. Energy is often produced by a heat engine, running on a source of high-temperature heat...
recovery - Off-peak power utilization: Heating hot water and Cooling
- Heat pumpHeat pumpA heat pump is a machine or device that effectively "moves" thermal energy from one location called the "source," which is at a lower temperature, to another location called the "sink" or "heat sink", which is at a higher temperature. An air conditioner is a particular type of heat pump, but the...
systems - Passive storage in bioclimatic building/architecture (HDPE, paraffin)
- Smoothing exothermicExothermicIn thermodynamics, the term exothermic describes a process or reaction that releases energy from the system, usually in the form of heat, but also in the form of light , electricity , or sound...
temperature peaks in chemical reactions - Solar powerSolar powerSolar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available...
plants - SpacecraftSpacecraftA spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....
thermal systems - Thermal comfortThermal comfortThermal comfort is a term used by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, an international body. It is defined as the state of mind in humans that expresses satisfaction with the surrounding environment...
in vehicles - Thermal protection of electronic devices
- Thermal protection of food: transport, hotel trade, ice-cream, etc.
- Textiles used in clothing
- Computer coolingComputer coolingComputer cooling is required to remove the waste heat produced by computer components, to keep components within their safe operating temperature limits.Various cooling methods help to improve processor performance or reduce the noise of cooling fans....
- Turbine Inlet Chilling with thermal energy storage
- Telecom shelters in tropical regions. They protect the high-value equipment in the shelter by keeping the indoor air temperature below the maximum permissible by absorbing heat generated by power-hungry equipment such as a Base Station SubsystemBase Station SubsystemThe base station subsystem is the section of a traditional cellular telephone network which is responsible for handling traffic and signaling between a mobile phone and the network switching subsystem...
. In case of a power failure to conventional cooling systems, PCMs minimize use of diesel generatorDiesel generatorA diesel generator is the combination of a diesel engine with an electrical generator to generate electrical energy....
s, and this can translate into enormous savings across thousands of telecom sites in tropics.