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The award-winning Phase Change Matters blog tracks the latest news and research on phase change materials and thermal energy storage. E-mail tips and comments to Ben Welter, communications director at Entropy Solutions. Follow the blog on Twitter at @PureTemp. Subscribe to the weekly PCM newsletter. Or join the discussion on LinkedIn.

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PCM briefing: Glacier Tek sponsors wheelchair cyclists in Kenya fundraiser; CCT closer to commercializing silicon battery

Ben Welter - Monday, September 09, 2019

Dom Coleman, Regain trustee and grants officerGlacier Tek LLC of Minneapolis is sponsoring seven quadriplegic cyclists taking part in a fundraising ride in Kenya's Rift Valley next month. The Kenya Cycle Challenge 2019, organized by Regain, a U.K.-registered charity, is on track to raise 80,000 pounds to support quadriplegic athletes in Great Britain. More than 50 riders are expected to participate. The seven sponsored riders will be wearing PureTemp-powered Glacier Tek cooling vests to help them handle the 32º C heat they will likely encounter on the five-day ride. People with spinal cord injuries are vulnerable to heat stress because their bodies cannot send the signals needed to initiate sweating in response to hot conditions. 

• Heat battery manufacturer Sunamp Ltd. is among the exhibitors at the InstallerSCOTLAND trade show in Glasgow, Scotland, on Thursday.

CCT Energy Storage is on track to install its first commercial thermal energy device at a mobile phone base station in Adelaide, South Australia, before the end of the year following an agreement in principle with an Australian infrastructure provider. CCT unveiled its first 24kW device in March, describing it as the world’s first working thermal battery using silicon as a phase change material.  

• Hundreds of Australia’s most environmentally advanced homes will open their doors to visitors on Sunday, Sustainable House Day 2019. At least two of the homes – Farrell’s House in Narara, New South Wales, and the 10 Star Home in Cape Paterson, Victoria – feature phase change technology. More than 33,000 people visited 226 homes across Australia last year.  

PureTemp shows energy-saving potential in EnergyPlus simulations

Ben Welter - Wednesday, August 28, 2019

In EnergyPlus simulations using hysteresis data, the integration of PureTemp phase change materials in a building's suspended ceiling tiles showed potential savings in cooling energy ranging from 5.5 percent to 37.4 percent.

Ceiling tile drawingThe PCM modeling research, conducted at University of Manitoba, also found a reduction in "discomfort hours" from 10 percent to 29 percent, depending on the zone and PCM type.

The researchers set out to investigate the feasibility of integrating PCMs within a suspended ceiling using the hysteresis method in EnergyPlus 8.9. The hysteresis effect, wherein a PCM has different melting/freezing temperature curves, complicates the simulation of PCM use in buildings. The EnergyPlus modeling software was updated in 2017 to include the effect of hysteresis.

Minneapolis-based PureTemp LLC provided the researchers with the thermo-physical properties of PCMs required for modeling in EnergyPlus. Five types of PCMs, namely PCM20 (PureTemp 20), PCM21, PCM22, PCM23 (PureTemp 23), and PCM24, were tested and analyzed. The melting and freezing temperatures of the five PCMs fall within the thermal comfort range and operation of the HVAC system of the building the researchers chose as a case study: the University of Manitoba's new Stanley Pauley Engineering Building.

Miroslava KavgicThe number of each PCM represents the material's peak melting temperature in degrees Celsius. The theoretical properties of PCM21, PCM22 and PCM24 were derived from the actual properties of PureTemp 20, PureTemp 23 and PureTemp 25.

One of the study's authors, Dr. Miroslava Kavgic, right, is an assistant professor of civil engineering at the university. She answered questions about the research by email.

Q: What do you think is the most important finding, as far as impact on manufacturers of PCMs and PCM products?

A: "The findings of our research study suggest a promising future for the applications of PCMs in buildings located in cold climates. Furthermore, our study showed that in addition to already proven cooling energy-saving potential, PCMs can be very efficient in reducing heating energy demand. As a result, the findings from our study can increase application of PCMs in buildings located in the dominant heating climates, and therefore increase the demand for these unique building materials. We also hope that higher demand for PCMs will bring down their price which currently hinders the more extensive application of PCMs in areas with the lower energy prices such as Manitoba."

Q: Why did you choose to use PureTemp data? Was there a preference to use a biobased PCM? Or was data on other products hard to obtain?

EnergyPlus model: enthalpy-temperature method
EnergyPlus PCM model, enthalpy-temperature method
A: "PureTemp shares valuable thermo-physical properties of its PCM products on its website. Furthermore, upon our request PureTemp provided additional information required for the modeling of PCMs in EnergyPlus using hysteresis method. PureTemp also provides other useful information related to various applications and experimental testing of PCMs. Finally, PureTemp’s PCM products are produced from agricultural sources, and they are readily biodegradable and non-toxic. These positive characteristics of the PureTemp’s PCM products can enable the development of environmentally friendly solutions that can significantly reduce buildings’ energy consumption while improving their indoor thermal comfort."

Q: Given the impact of a PCMs hysteresis the final simulation results, is there a standard you’d like the industry to establish for consistent data from the PCM manufacturers?

EnergyPlus model: hysteresis method
EnergyPlus PCM model, hysteresis method

A: "Consistent data from the PCM manufacturers would increase confidence in the modeling results, and this applies to both hysteresis and temperature-enthalpy methods. Moreover, the consistent PCM properties could also be beneficial for the manufacturers as they will allow the end-user to test multiple PCMs and purchase several different materials for real-world implementation. This is particularly important considering the need for numerical analysis before the real-world implementation due to both complex behavior of PCMs and their relatively high price. The sensitivity analysis of the hysteresis input parameters suggests that manufacturers should pay partial attention to the parameters that have high impact on the simulation results."

Q: For future work, is there interest in comparing the same PCM measured with different methods, such as T-history and DSC?

A: "The t-history method is relatively inexpensive and straightforward to measure the phase-change enthalpy of PCM products using considerably larger sample sizes compared to DSC, and therefore for non-uniform PCMs it is a good testing alternative to DSC."

Table 3. Thermo-physical properties of the tested PCM:

Hysteresis properties PCM20 PCM21 PCM22 PCM23 PCM24
Latent heat during the entire phase change process (J/kg) 171,000 189,000 208,000 227,000 207,000
Peak melting temperature (°C) 20 21 22 23 24
Peak freezing temperature (°C) 18 19 20 21 22
Liquid-state thermal conductivity (W/(m∙K)) 0.14 0.143 0.146 0.15 0.15
Solid-state thermal conductivity (W/(m∙K)) 0.23 0.236 0.243 0.25 0.25
Liquid-state density (kg/m3) 680 730 780 830 840
Solid-state density (kg/m3) 950 936 923 910 930
Liquid-state specific heat (J/(kg∙K)) 2150 2096 2043 1990 2140
Solid-state specific heat (J/(kg∙K)) 2070 1993 1916 1840 1915

 

The full version of the paper is available here through the end of September 2019:

https://authors.elsevier.com/a/1ZZ3u4r6KuzlE4

Research roundup: Microencapsulated coconut oil; mixed alkanes microcapsules; low-hydration heat cement slurry; more

Ben Welter - Tuesday, August 27, 2019

From Cellulose:

Microencapsulated organic coconut oil as a natural phase change material for thermo-regulating cellulosic fabrics

From Journal of Physics: Conference Series:

Numerical and experimental investigation of melting process in spherical PCM capsule used for low-temperature thermal energy storage systems

From Energy:

Synthesis and characterization of mixed alkanes microcapsules with phase change temperature below ice point for cryogenic thermal energy storage
Preparation of Low Hydration Heat Cement Slurry with Micro-encapsulated Thermal Control Material

From Applied Thermal Engineering:

A Three-Dimensional Numerical Investigation of a Novel Shallow Bore Ground Heat Exchanger Integrated with Phase Change Material

From Polymer Science:

Preparation of Phase Change Microcapsules with Inorganic/Polymer Hybrid Shell Through a “Two-Step” Reaction

From Solar Energy:

Improved thermal energy storage for nearly zero energy buildings with PCM integration

From Thermal Science and Engineering Progress:

A theoretical and experimental study of a TBAB salt hydrate based cold thermal energy storage in an air conditioning system

From Journal of Energy Storage:

A Review of Phase Change Materials for the Thermal Management and Isothermalisation of Lithium-Ion Cells

From Energy Conversion and Management:

Experimental performance evaluation of a novel designed phase change material integrated manifold heat pipe evacuated tube solar collector system

From Renewable and Sustainable Energy Reviews:

Corrosion mechanisms in molten salt thermal energy storage for concentrating solar power

PCM briefing: ThermoSafe introduces new passive shipper; PCM-cooled rail containers hit market in China

Ben Welter - Saturday, August 24, 2019

ThermoSafe Pegasus ULD shipper• Sonoco ThermoSafe has announced the creation of a passive, temperature-controlled container that will be manufactured by AEROTUF of Charleston, S.C. The Pegasus ULD container will use AEROTUF’s patented AeroTHERM composite material technology, along with a gelled phase change material. "The Pegasus ULD will ultimately provide 2-8, CRT, and frozen temperature ranges depending on the PCM used for durations up to and exceeding five days," said Ben VanderPlas, manager of Engineering and Product Management at ThermoSafe, which is based in Arlington Heights, Ill. A launch date for the product has not been announced.

• The Chinese rail company that worked with the UK's University of Birmingham last year to develop a prototype of PCM-based freight container is bringing the concept to market. Hebei-based transport business CRRC Shijiazhuang sold 49 of the containers to a manufacturer in China this month. The low-emissions freight containers keep payloads cold without the need for fuel-generated refrigeration. "We are delighted to see our cold storage technologies start to make the commercial market," said Yulong Ding, director of the Birmingham Centre for Energy Storage. "We are working with our partners to extend the cold storage technologies to more applications."

Lagunitas Phase Change ale• Here's a co-branding opportunity for a PCM manufacturer with a taste for hops: Lagunitas Brewing Co. of Petaluma, Calif., has introduced Phase Change, "an unfiltered, wet-hop ale packed full of lupulin-drenched Simcoe, Citra & Mosaic hops." The brewer describes the beer as "somewhere between a solid and a liquid... a Phase Change of sorts."  

• More than 170 speakers are lined up for the 14th International Conference on Advanced Building Skins, to be held Oct. 28-29 in Bern, Switzerland. The Japanese architect and Pritzker laureate Shigeru Ban will deliver the keynote address. Thomas Friedrich of Innogration GmbH, Germany, will discuss "collection of thermal energy from the façade" and "decentralized PCM storage elements for saving thermal energy." Damien Mathis of Ai Environnement, Paris, will give a presentation on the "thermal performance of engineered wood flooring impregnated with phase-change materials." The registration fee is 680 euros and includes the conference documentation as well as meals during both days. Participants who register by Aug. 30 will receive a 10 percent discount.

Research roundup: Microencapsulated sugarcane wax; night ventilation; caprylic acid composite; more

Ben Welter - Friday, August 23, 2019

From Chemical Engineering:

Thermal properties and behavior of microencapsulated sugarcane wax phase change material

From Renewable Energy:

Experimental study on the influence of preparation parameters on strengthening stability of phase change materials (PCMs)
Climatic and seasonal suitability of phase change materials coupled with night ventilation for office buildings in Western China

From Applied Energy:

Thermal energy storage (TES) with phase change materials (PCM) in solar power plants (CSP). Concept and plant performance

From Materials Research Express:

Preparation and thermal characteristics of caprylic acid based composite as phase change material for thermal energy storage

From Energy Conversion and Management:

Thermodynamic assessment of an integrated renewable energy multigeneration system including ammonia as hydrogen carrier and phase change material energy storage

From Russian Journal of General Chemistry:

Symmetrical Fatty Dialkyl Carbonates as Potential Green Phase Change Materials: Synthesis and Characterisation

From Journal of Physics: Conference Series:

An Integrated Energy Power Generation with Energy Storage System

From Safety in Extreme Environments:

Review of energy storage technologies in harsh environment

From Materials Today: Proceedings:

Review on performance assessment of phase change materials in buildings for thermal management through passive approach

From International Journal of Environmental Science and Technology:

Sunlight-driven organic phase change material-embedded nanofiller for latent heat solar energy storage

From International Journal of Energy Research:

Application of a ground source heat pump system with PCM‐embedded radiant wall heating for buildings

From Industrial & Engineering Chemistry Research:

Theoretical Evaluation of an Organic Phase Change Material (PCM)-Inserted Dual-Functional Adsorbent for the Recovery of Heat of Adsorption

From Chemical Engineering Journal:

Flame-retardancy and thermal properties of a novel phosphorus-modified PCM for thermal energy storage

From Solar Energy:

Numerical study on charging characteristics of heat pipe-assisted cylindrical capsule for enhancing latent thermal energy storage

From Renewable Energy and Environmental Sustainability:

Use of phase change materials in concrete: current challenges

From Solar Energy Materials and Solar Cells:

Ambient pressure dried flexible silica aerogel for construction of monolithic shape-stabilized phase change materials

From Applied Thermal Engineering:

Preparation and properties of phase change temperature-tuned composite phase change material based on sodium acetate trihydrate–urea/fumed silica for radiant floor heating system

From Sustainable Cities and Societies:

Cardinal orientation and melting temperature effects for PCM-enhanced light-walls in different climates

From Journal of Thermal Analysis and Calorimetry:

Phase change materials (PCMs) for improving solar still productivity: a review

Patent application: Substance delivery device with PCM

Ben Welter - Thursday, August 22, 2019

U.S. patent application 20190254797 (applicant TG Medwise Ltd., Hod HaSharon, Israel):

PCM collar patent drawing"A delivery device includes a collar device for wearing on an animal, a dosing probe disposed on the collar device for delivering a substance therefrom, an actuator configured to deliver the substance from the dosing probe through an opening formed in the dosing probe, a controller in communication with the actuator and configured to control delivery of the substance from the dosing probe, and a sensor in communication with the controller and configured to sense that the collar device is touching fur or skin of the animal and the dosing probe is directed towards fur or skin of the animal."

http://www.freepatentsonline.com/20190254797.pdf

Patent application: Article of clothing with PCM

Ben Welter - Thursday, August 22, 2019

Under Armour patent drawingU.S. patent application 20190254362 (applicant Under Armour Inc., Baltimore, Md.):

"The present invention is directed toward an article of apparel effective to regulate the temperature of the wearer. In an embodiment, the article of apparel includes a base textile with a thermal regulation membrane. The thermal regulation membrane contains a plurality of system-reactive components selectively engaged heat and/or moisture. In an embodiment, the printed coating includes a cooling agent, a phase change material, and a heat dissipation material. In operation, the article of apparel is effective to delay/diminish the rise in skin temperature (compared to a garment lacking the membrane), increasing wearer comfort."

http://www.freepatentsonline.com/20190254362.pdf

Patent application: Ice-based thermal energy storage device

Ben Welter - Thursday, August 22, 2019

U.S. patent application 20190257593 (applicant Boreales Energy, Hérouville-Saint-Clair, France):

"Disclosed is a heat exchange device including a first thermally conductive tube that is hollow over its length, a second thermally conductive tube that is hollow over its length, and including a thermally conductive fin, in which the fin extends lengthwise along the first tube, the fin extends lengthwise along the second tube and the fin extends width-wise between the first tube and the second tube. ... The invention is open to industrial application or useful in the field of heat accumulators, transferring heat between two phase change materials and in particular for storing energy in the form of ice from freshwater or saltwater or brackish water."

http://www.freepatentsonline.com/20190257593.pdf

PCM briefing: Funding for AMP Clean Energy project; 1414 Degrees to test 'SmartFarm" applications

Ben Welter - Monday, August 19, 2019

Innovate UK’s Knowledge Transfer Partnership has awarded funding to a joint effort by AMP Clean Energy and the University of Birmingham to develop a thermal energy storage system. The system will incorporate phase change material developed by the university for use in AMP’s Urban Reserve flexible electricity generation plants, which will turn waste heat into electricity. The amount of funding was not disclosed.

• Geocryologist Christopher Stevens of SRK North America will give a PCM-related presentation at this week's International  Conference on Cold Regions Engineering in Quebec City: "Phase Change Materials – Innovation in Adaptation Technology to Address Permafrost Thaw" (Aug. 21).

• Australian start-up 1414 Degrees has announced a joint project with Nectar Farms to test “SmartFarm” applications of 1414's technology, which stores electricity as thermal energy by heating and melting containers full of silicon. 

Patent application: Temperature regulating polyurethane gel

Ben Welter - Thursday, August 15, 2019

U.S. patent application 20190249058 (applicant Technogel Italia S.r.L., Pozzoleone, Italy):

"A method for the production of a temperature regulating polyurethane gel composition and corresponding articles includes fatty acid esters as a phase change material (PCM) directly incorporated in the fluid phase of a polyurethane gel without encapsulation. The liquid or melted PCM is solved in the polyol component of the gel and is able to crystallize and melt within the gel structure reversibly. The polyurethane gels are under-crosslinked and include an at least nominal three functional ethylene oxide-comprising alkylene oxide polyether polyol with 0 to 40% EO and an isocyanate with an effective functionality of from 1.5 to 3.5. The gels are useful in articles where the gel can be positioned close to the human body for temperature regulating purposes, and especially to improve the sleeping comfort of a resting person."

http://www.freepatentsonline.com/20190249058.pdf