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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.

Two Entropy advisors, Dr. Mohammed Farid and Lucas B. Hyman, are pleased to take your questions about PCMs and thermal energy storage. Send your questions to bwelter@puretemp.com. We'll select the best and post the answers here each week.

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Research roundup: Transient energy storage; metal alloys for high-temperature applications; low-cost PCM emulsion; more

Ben Welter - Wednesday, July 12, 2017

Transient thermal energy storage in partitioned enclosures packed with microencapsulated phase change materials [International Communications in Heat and Mass Transfer]

Considerations for the use of metal alloys as phase change materials for high temperature applications [Solar Energy Materials and Solar Cells]

Experimental analysis of a coiled stirred tank containing a low cost PCM emulsion as a thermal energy storage system [Energy]

Fabrication and characterization of novel shape-stabilized synergistic phase change materials based on PHDA/GO composites [Energy]

Fabrication of hard-shell microcapsules containing inorganic materials [International Journal of Refrigeration]

Renewable Energy and Energy Storage Systems [Energy]

Thermal Storage Capacity and Night Ventilation Performance of a Solar Chimney Combined with Different PCMs [International Journal of Photoenergy]

Preparation and characterizations of asphalt/lauric acid blends phase change materials for potential building materials [Construction and Building Materials]

Numerically Study the Performance of An Air—multiple PCMs unit for Free Cooling and Ventilation [Energy and Buildings]

Research roundup: Macro-packed fatty acid ester composites; selective laser sintering; more

Ben Welter - Tuesday, July 11, 2017

From Journal of Industrial and Engineering Chemistry:

Performance evaluation of macro-packed fatty acid ester composites using energy-efficient thermal storage systems

From Procedia Manufacturing:

Selective Laser Sintering of Phase Change Materials for Thermal Energy Storage Applications

From Applied Energy:

Synthesis and characterization of microencapsulated myristic acid–palmitic acid eutectic mixture as phase change material for thermal energy storage
Advances in thermal energy storage materials and their applications towards zero energy buildings: A critical review

From Solar Energy Materials and Solar Cells:

A new strategy for enhanced latent heat energy storage with microencapsulated phase change material saturated in metal foam
Preparation and characterization of hybrid nanocomposite embedded organic methyl ester as phase change material

From Renewable Energy:

Cutting copper fiber/paraffin composite phase change material discharging experimental study based on heat dissipation capability of Li-ion battery

From Lehigh University:

Numerical and Experimental Study of the Melting Process of a Phase Change Material in a Partically Filled Spherical Shell [thesis]

From IEEE Internet Computing:

Thermal Time Shifting: Decreasing Datacenter Cooling Costs with Phase Change Materials

From International Journal of Heat and Mass Transfer:

Numerical modeling of solid-liquid phase change in a closed 2D cavity with density change, elastic wall and natural convection

From Applied Thermal Engineering:

Evaluation of the suitability of different calorimetric methods to determine the enthalpy-temperature curve of granular PCM composites
Heat Transfer Enhancement during Freezing Process of Nano Phase Change Material (NPCM) In a Spherical Capsule
Numerical simulation on thermal characteristics of supercooled salt hydrate PCM for energy storage: Multiphase model

Patent application: Technologies for releasing thermal energy

Ben Welter - Tuesday, July 11, 2017

U.S. patent application 20170188754 (inventor Melissa Zimberg, Maplewood, N.J.):

"A heat unit containing a phase change material consisting of polyethylene glycol and a fatty acid combination of stearic and palmitic acids is disclosed. When heated in a microwave for about four (4) minutes the heat unit reaches a temperature of about 70° C. (158° F.). When placed in an insulated container, the heat unit will, after six (6) hours, have a temperature of about 40° C.-55° C. (104° F.-131° F.). The heat unit is advantageous for maintaining food hot during transport as well as other uses where long term heat emission is needed."

http://www.freepatentsonline.com/20170188754.pdf

UK student honored for designing mobile cooler for fish vendors

Ben Welter - Tuesday, July 11, 2017

Fish vendor basket

A University of Hertfordshire student who designed a fish cooler for street vendors is the runner-up in the UK’s prestigious New Designer of the Year competition. The New Designers exhibition, now in its 32nd year, features the work of top students from the UK’s leading design schools.

Kiran Sunil’s “Machhalee Basket” is essentially an EPS cooler equipped with phase change material. Judges described it as “a sensitively designed product – an example of bottom-up, frugal innovation, demonstrating genuine social impact and purpose.” The award includes a cash prize of £500.

Sunil, 22, was born and raised in the United Kingdom and is of South Indian descent. He recently earned a bachelor's degree in industrial design at Hertfordshire. He discussed details of his final-year project in an email interview.

Kiran Sunil with winning displayQ: What does “Machhalee” mean?

A: "Machhalee" is a Hindi word for “fish.”

Q: How did you come up with the idea?

A: My family and I regularly travel to India usually every 2-3 years, so for me the sight of fish vendors on street corners and at local marketplaces was a common and familiar sight, as it is to native Indians. However it always occurred to me the huge contrast between our experience in places like the UK of buying fish in comparison to theirs. Often their platform was very makeshift, working from the ground unprotected in the baking hot sun and with little to no ice. Generally poor quality.

In conjunction for my dissertation I gained a deeper insight into what I wanted to do for my final project, when I began tackling issues between wealth divides and how this affects the designs that we consume and use. Inspired by the works of Victor Papanek and Emily Pilloton of designing for social change, I decided that for this project I wanted to design something for those less well off in developing countries, those who were in true need of good design. However it was important for me that I didn't want to create a product that revolved around aid. This was about empowerment and strengthening honest business, more importantly I wanted to create a product from the people and for the people.


Q: Did you talk with fish vendors as part of your research?

A: While I wasn’t able to talk directly to fish vendors in India due to the disconnect, I came pretty close. It was important that I design honestly and according to the needs of the vendors. I enlisted the help of many NGOs including the likes of the Selco Foundation in India as well as the National Association of Street Vendors of India, two huge players in my research. With their help I was able to identify all the key needs, patterns and processes in order to create the most appropriate design.

Q: How did you hear about phase change material?

A: One of my visiting lecturers, Ian Hunter from Material Council, mentioned its usage in cheap and effective cooling systems and so it piqued my interest. For a while we gained and lost interest in the idea while the designs developed before finally realizing it massive potential.

Q: How many PCM types did you try before settling on one?

A: I researched PCMs for a duration while doing the project. I moved from organic paraffin wax based ones to salt hydrates and so on. Ultimately I decided that using more environmentally friendly sources such as vegetable and animal fat PCMs would be better due to their stability, sustainability, re-use and wide temperature range. Also it occurred to me that it was possible for these PCMs to be locally manufactured and sourced by farmers, making it possible for them to benefit from the mix as well.

Q: Which PCM are you using and how is it contained?

Sunil basket cutawayA: After getting in contact with your associates at Entropy Solutions, I decided that PureTemp 8 from your range was the most appropriate due to it being agriculturally sourced and having a great heat storage capacity of 178J/g. It was also important that the PCMs be cooled passively at similar temperatures that ice are stored and manufactured in. In this case it was so that Ice vendors were still inclusive in process and could supply and recharge the PCM packs using their facilities at a fixed lease based price to the fish vendors. The fish vendors in turn would use the packs and return them in the evening for recharging, creating a harmonious cold chain.

I decided macroencapsulation was the best and most secure way to go using the plastic pouch method. On top of this the pouches [shown in yellow in cutaway drawing] would sit inside thin sheet metal aluminum containers, adding an extra layer of protection while still allowing for heat conduction
.

Q: What if any insulation material is used in the cooler?

A: The majority of the insulation comes from the medium grade EPS that makes up the main body of the basket. This is a common and cheap material used in the fishing trade and so seemed appropriate. On top of this on the interior the fish sits inside a polyester tarpaulin bag and on the exterior the main body sits inside a secondary woven bamboo basket.

Q: How long did it take you to complete the project, from concept to prototype?

A: About 3½ months. It was part of our second semester and made up our final major project.

Q: What do you estimate the retail cost might be, when in full production?

A: I designed and planned the cooler in such a way for minimal cost with maximum effect. I truly made use of the fruits of India's economy when considering how to do this. All materials are locally sourced and in abundance either by methods of cheap manufacture or locally available materials making it easy to repair and easy/cheap to replace.

On top of this I took into consideration the consumption styles of vendors and realized that what might work best was a lease-based platform. In this case the vendors could buy the basket outright for a small price and were given the opportunity to lease/purchase the PCM packs and display assembly if they required it. All costs considered, I estimate the vendors expenses would be no more than 20 rupees a week.


Q: Do you have plans to commercialize the cooler?

A: A few companies have shown interest in commercializing the cooler. However while it shows great promise and practicality, for now it is just a concept and has room for development and improvement, if it is to be successfully implemented. I believe in an open sourcing philosophy, especially when it comes to the potential for my target audience that it could help.

Q: What do you plan to do with the £500 prize?

A: I plan on using it to re-invest in my career, however I’m not sure entirely how. I might purchase a new laptop, or I could possibly use it for a plane ticket if the opportunity to take my work elsewhere calls!

PCM briefing: Cleanergy lands CSP contract in China; ASHRAE extends global reach

Ben Welter - Monday, July 03, 2017

• Team Sky cyclists competing in this year's Tour de France are using Inuteq's Siku vest to cool down after each stage. The Dutch company's hybrid vest combines PCM and evaporative cooling technologies. Inuteq says it is supplying its cooling products to two other teams: Bahrain Merida and Cannondale Drapac.

Calmac, the New Jersey company whose thermal energy storage tanks help cool more than more than 4,500 buildings worldwide, including the corporate headquarters of JC Penney, Marriott and Google, was profiled in Inc. magazine last week.  

Ember Technologies' temperature-controlled mug is a finalist in the 2017 International Design Excellence Awards in the Kitchen & Accessories category. The winners will be announced Aug. 16 at the International Designers Society of America conference in Atlanta. 

Cleanergy AB of Sweden has signed an agreement to deploy a 200-MW concentrating solar energy project in China. A Cleanergy spokeswoman confirmed that phase change material will be used in the CSP project's thermal storage system but declined to provide details about the PCM. 

Midsize energy and chemical companies are among the least prepared for the disruption that technological innovation and other changes will bring, a new report from Capital One Commercial Bank says.

• A U.S. House appropriations subcommittee last week advanced a bill that would impose deep cuts in renewable energy and efficiency programs at the Department of Energy and eliminate the Advanced Research Projects Agency-Energy, ARPA-E.

ASHRAE has announced the formation of a new ASHRAE Region in Europe and strategic partnerships with two European organizations: the UK-based Chartered Institute of Building Services Engineers and the Belgium-based Federation of European Heating, Ventilation and Air-Conditioning Associations.

• PCM will be among the topics at the 3rd International Conference: Innovative Materials and Smart Technologies for Environmental Safety. The conference will take place Sept. 27-29 in Latvia. The student conference includes a lecture titled "Heat Transfer Enhancement in Phase-Change Materials" by Dr. Gennady Ziskind, professor of mechanical engineering at Ben-Gurion University of the Negev, Israel. 

BASF, Cargill, Procter & Gamble and the Deutsche Gesellschaft für Internationale Zusammenarbeit GmbH have joined together in a development partnership to help establish a sustainable certified and transparent supply chain of coconut oil in the Philippines and Indonesia.  

• New from Zion Market Research: "Temperature Controlled Packaging Market: Global Industry Analysis, Size, Share, Growth, Trends, and Forecasts 2016–2024"

Bio-Based World News reports that the biobased sector of Finland's economy is now worth 60 billion euros. About 60 percent of the sector is rooted in the country's forest industry. 

Effort to commercialize EpiPen container hits unexpected roadblock

Ben Welter - Monday, June 19, 2017

Commercializing an invention can be a herculean task. There are technical hurdles. Funding hurdles. Patent hurdles. Manufacturing hurdles. Regulatory hurdles. Eric and Sandy Wengreen, co-founders of a company working to commercialize a small container that uses phase change material to keep EpiPens close to room temperature, are familiar with all of it.

Sandy and Eric WengreenFirst, the invention:

After their son nearly died of a severe allergic reaction to macadamia nuts a few years ago, the Seattle couple realized the importance of having an EpiPen auto-injector handy at all times. Sandy invented the container, now known as MedShell, to ensure that people can take their EpiPen wherever they go, even if it’s hot or cold outside. It’s not just about being prepared for an unexpected allergic reaction. EpiPens are expensive. Leave one in a hot car or gym bag for a few hours and you’re out $300.

The Wengreens began developing their device, originally called EpiShell, a few years ago. They filed for patents and successfully tested prototypes.

Biobased phase change material is a key component of the MedShell, which is designed to keep EpiPens between 15º and 30º Celsius (59º and 86º Fahrenheit).

“I learned about PCM while I was researching how to change the melting temperatures of liquids,” says Eric, who has a master’s degree in engineering from Stanford University. “I was very happy to discover that Entropy Solutions had already engineered highly reliable PCM. At that point, I realized that I didn't need to re-invent the wheel. Instead, I simply ordered PureTemp samples for prototyping and testing. I also received samples from other PCM manufacturers, but I quickly found out that PureTemp PCM was superior.”

Last fall, after receiving written assurance from the U.S. Food and Drug Administration that the container would not be considered a medical device subject to FDA regulatory requirement, the Wengreens launched an Indiegogo campaign. The fundraising target: A modest $35,000.

Medshell temperature-control container for medicines“My goal was to raise awareness (rather than just raise money),” Eric says. “Most people don't know many medicines have strict storage-temperature requirements. I also wanted to test the market to see if other people cared about protecting their medicines from temperatures that are hotter and colder than the FDA-approved temperature limits.”

The response was strong. Within a few months, the campaign drew hundreds of backers and raised nearly $30,000. Two product videos were watched more than 15,000 times on YouTube. The Wengreens continued to refine the design of the vacuum flask and thermal management system. They began evaluating manufacturing options.

In November, they decided to change the name of the product to MedShell.

“Many people have talked with us about applications beyond epinephrine, the active ingredient in EpiPens,” Eric says. “As a result, we wanted the name to reflect our broader mission to protect many medicines from hot and cold temperatures. … Essentially, the storage-temperature requirements vary depending on the medicine, but the fundamental technology is the same, so MedShell can be adapted to just about any medicine.”

On Dec. 7, Eric alerted Indiegogo backers to an unexpected development:

“Recently, in an abundance of caution, we voluntarily asked the FDA to conduct a second review of our product.  This time, we had detailed product information that was not available during the first review (because we had not finished the design details at the time of the first review). During this second review, the FDA decided that MedShell is a medical device subject to FDA regulatory requirements.”

The FDA’s decision, Eric told backers, “will dramatically delay our launch and increase our expenses.” The Wengreens suspended the Indiegogo campaign and offered refunds to all backers.

The Wengreens announced a new strategy in a January post on Indiegogo: “We now need to find a larger company that has the FDA expertise and resources to bring MedShell to market.” They continue to fund development with money earned from previous inventions.

The regulatory hurdle looms large, but the Wengreens remain committed to commercializing the product.

“Whether MedShell is a medical device is debatable,” Eric says. “Honestly, I don't know exactly what would be required to either convince the FDA that MedShell is not a medical device or meet the FDA's medical-device requirements. I reached out to the FDA for guidance, but I have not gotten specific answers regarding next steps.”

Although they have no plans to reopen the Indiegogo campaign, the Wengreens say they want to make sure supporters have the first opportunity to get the device when it launches. Consumer interest remains strong; MedShell's YouTube videos have now been viewed more than 76,000 times. 

“My goal is to transfer my patents and designs to a company with the resources to remove the FDA uncertainty and bring the product to market,” Eric says. “A larger company is better suited to making the invention widely available.”

Research roundup: Polystyrene microcapsules; vermiculite composites; topology optimization; more

Ben Welter - Friday, June 16, 2017

Polystyrene Microcapsules with Palmitic-Capric Acid Eutectic Mixture as Building Thermal Energy Storage Materials [Energy and Buildings]

Preparation and characterization of capric-palmitic-stearic acid ternary eutectic mixture/expanded vermiculite composites as form-stabilized thermal energy storage materials [Journal of Materials Science and Technology]

Topology optimization for heat transfer enhancement in Latent Heat Thermal Energy Storage [International Journal of Heat and Mass Transfer]

Investigating thermal properties of using nano-tubular ZnO powder in paraffin as phase change material composite for thermal energy storage [Composites Part B: Engineering]

PCM replacement cap keeps insulin pens at the right temperature

Ben Welter - Monday, June 05, 2017

VIVA insulin cap

Insulin pens must be kept between 15° and 30° Celsius to ensure safe and effective injection. An Israeli company has developed a cap that combines phase change material with monitoring electronics to keep these pens from overheating in hot environments.

TempraMed’s first-generation Vivi Cap1 fits over any type of insulin pen and adjusts constantly to keep the insulin at the higher end of room temperature. When the device is exposed to temperatures above 29° C, the bio-based PCM begins to absorb heat and change from solid to liquid. When the ambient temperature falls below 28° C, the PCM starts to return to its solid state, allowing it to regain its heat-absorbing property. A push of a button at the base allows the user to confirm that the insulin is at the proper temperature.

“We are not aware of similar products that are available on the market,” said Ron Nagar, TempraMed president and CEO. “Until now, most commonly used products for ‘keeping insulin cool’ use water evaporation technology, which requires frequent user intervention, and is not effective in closed bags (where medication is commonly carried) or in humid environments.

“With the insulation and PCM we use, we offer very compact solutions (slightly larger than current insulin pen cap) which can maintain the proper conditions for time durations that are typically longer than the exposure expected during daytime or when outdoors, and allow recovery during the night or when back indoors, without user intervention.”

TempraMed is based in Tel Aviv with an office in Washington State. The products are manufactured in Israel.

The FDA- and CE-registered Vivi Cap1 is available now on the company’s website, www.my-vivi.com, at a cost of $49.90. The next generation of Vivi products will be available in the fall: Vivi Epi for epinephrine pens; Vivi Vial for insulin vials; and Vivi Cool 8° C and Vivi Vial 8° C for storing insulin at lower temperatures.

Nagar said TempraMed is working with several distributors to make the products widely available, including retail chains.

http://www.healthline.com/diabetesmine/insulin-cooling-tempramed-giveaway

Patent application: System for energy consumption reduction and cost savings in a building

Ben Welter - Tuesday, May 30, 2017

U.S. patent application 20170146251 (applicant Stasis Group Inc., Woodland, Calif.):

"A system for obtaining energy consumptions, savings and cost reduction in structures adapted for human habitation which includes the utilization of a plurality of mats including phase change material encapsulated within first and second layers of plastic material [3.6, above] having heat transfer capability disposed within the plenum area above a ceiling of a room within a building with the amount of phase change material contained within each mat being between 0.5 lbs. and 0.67 lbs. per square foot. ... [The] solid to liquid transition point for said phase change material is from 72° F. to 76° F. and the liquid to solid transition point for said phase change material is from 71° F. to 68° F."

http://www.freepatentsonline.com/20170146251.pdf

Research roundup: Cenospheres in concrete; form-stable composites with polyacrylic; rice bran distilled fatty acid; more

Ben Welter - Thursday, April 13, 2017

Numerical studies on thermal and electrical performance of a fully wetted absorber PVT collector with PCM as a storage medium [Renewable Energy]

Integrating phase change materials into concrete through microencapsulation using cenospheres [Cement and Concrete Composites]

Testing and performance analysis of micro encapsulated rice bran distilled fatty acid [International Journal of Computer Aided Engineering and Technology]

Enhanced thermal management with microencapsulated phase change material particles infiltrated in cellular metal foam [Energy]

Thermal performance study of form-stable composite phase change material with polyacrylic [AIP Conference Proceedings]

Design and Preparation of Carbon Based Composite Phase Change Material for Energy Piles [Materials]

Single-walled carbon nanotube for shape stabilization and enhanced phase change heat transfer of polyethylene glycol phase change material [Energy Conversion and Management]

Applications of Nanocomposite-Enhanced Phase-Change Materials for Heat Storage [Materials Science Forum]

Fatty acids and related phase change materials for reliable thermal energy storage at moderate temperatures [Solar Energy Materials and Solar Cells]

A study of a eutectic salt of lithium nitrate and sodium chloride (87–13%) for latent heat storage [Solar Energy Materials and Solar Cells]

Thermal stabilization and permanent deformation resistance of LWA/PCM-modified asphalt road surfaces [Construction and Building Materials]