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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.




Patent application: Lightweight composite overwrapped pressure vessels with sectioned liners

Ben Welter - Monday, July 02, 2018

U.S. patent application 20180180221 (applicant Steelhead Composites LLC, Golden, Colo.):

"The present invention provides a lightweight high pressure vessels that are made from a liner or a liner housing that is overwrapped with a composite material. Unlike conventional high pressure vessels, the lightweight high pressure vessel of the invention includes a liner that comprises a plurality of liner sections without using welding or crimping. In particular, the lightweight high pressure vessels of the invention include a plurality of elements that are combined to form a liner housing and a composite overwrap that provides structural and mechanical strength to maintain integrity of the high pressure vessel. In one particular embodiment, the high pressure vessel of the invention is a diaphragm accumulator. ... [In some embodiments] interior of said accumulator comprises a phase changing material."

Patent application: Gel cosmetic applicator

Ben Welter - Monday, July 02, 2018

Gel applicator patent drawing

U.S. patent application 20180177280 (applicant HCT Group Holdings Ltd., China):

"Cosmetics packaging and applicators including a gel based tip are described. Gel applicators may or may not be provided with a through-hole. In various embodiments, the gel may be a stand-alone gel or may be encapsulated in a membrane. The gel applicator provides a soft feel and may have cooling effect as well. In some embodiments, the applicator is mounted to a platform or a hollow insert and coupled to a container housing the cosmetics product. ... The gel may also include phase change materials which are useful in conveying the cooling sensation, since phase change materials, by definition absorb heat energy when changing phases."

Patent application: Heating control method and heating control device for battery structure

Ben Welter - Monday, July 02, 2018

U.S. patent application 20180183115 (applicant Contemporary Amperex Technology Co. Ltd., Ningde, China):

"A battery system, comprising a battery structure, a heating assembly, and the heating control device according to claim 7, wherein the heating control device is electrically connected with the heating assembly and the battery structure to form a control circuit, and the heating assembly is configured to heat the battery structure under control of the heating control device. ... Preferably, the heating assembly includes a heater, and a resistance of the heater increases as a temperature of the heater increases. Preferably, the heating assembly further includes a phase change material, the heater contacts with the phase change material, the phase change material is capable of changing phase at a phase change temperature, and heat generated by the heater is conducted to the battery structure via the phase change material."

Research roundup: Carbonized wood-based composite; inclined photovoltaic system; nanoparticle-enriched PCM; more

Ben Welter - Monday, July 02, 2018

From Energy:

Low-cost, three-dimension, high thermal conductivity, carbonized wood-based composite phase change materials for thermal energy storage
Coupled Cooling Method for Multiple Latent Heat Thermal Storage Devices Combined with Pre-cooling of Envelope: Model Development and Operation Optimization
Latent and sensible heat analysis of PCM incorporated in a brick for cold and hot climatic conditions, utilizing computational fluid dynamics

From International Journal of Heat and Mass Transfer:

Study on a PEG/epoxy shape-stabilized phase change material: Preparation, thermal properties and thermal storage performance

From Journal of Cleaner Production:

Research on the Application of Phase-change Heat Storage in Centralized Solar Hot Water System

From Applied Thermal Engineering:

Numerical study of an inclined photovoltaic system coupled with phase change material under various operating conditions

From Solar Energy:

Effect of MOF derived hierarchical Co3O4/expanded graphite on thermal performance of stearic acid phase change material
Numerical analysis of a new thermal energy storage system using phase change materials for direct steam parabolic trough solar power plants

From Applied Energy:

Cyclic performance of cascaded and multi-layered solid-PCM shell-and-tube thermal energy storage systems: A case study of the 19.9 MWe Gemasolar CSP plant

From Journal of Energy Storage:

Experimental investigation of transient melting and heat transfer behavior of nanoparticle-enriched PCM in a rectangular enclosure

From Desalination:

Theoretical study on the performance of a solar still system integrated with PCM-PV module for sustainable water and power generation

From Solar Energy Materials and Solar Cells:

Graphene Aerogels Enhanced Phase Change Materials prepared by one-pot method with high thermal conductivity and large latent energy storage
Facile approach to improve solar thermal energy storage efficiency using encapsulated sugar alcohol based phase change material

PCM briefing: Cash infusion for Ice Energy; ASHRAE's new energy audit standard now available

Ben Welter - Monday, July 02, 2018

Ice Energy, make of the Ice Bear and other ice-based energy storage systems, is getting an infusion of cash from a private equity manager. The California startup will receive $40 million from Argo Infrastructure Partners to finance the delivery of its residential and commercial thermal storage contracts.

• "Chemistry for the Non-Chemist," a four-part online course offered by Chemical Watch, promises "a solid introduction to chemistry." The cost: $450.  

ASHRAE Standard 211 is now available for download. The standard "establishes consistent practices for conducting and reporting energy audits for commercial buildings. The standard defines the procedures required to perform Energy Audit Levels 1, 2, and 3; provides a common scope of work for these audit levels for use by building owners and others; c. establishes consistent methodology and minimum rigor of analysis required; and establishes minimum reporting requirements for the results of energy audits." 

Purchase College of New York will get a free replacement for its aging central heating plant, thanks to a collaborative thermal energy storage project from the New York Power Authority and Brenmiller Energy. The R&D project will investigate sensible thermal energy storage as a way to increase the efficiency of a standard combined heat and power system. The new system could save State University of New York $100,000 a year.

Fifty-four academic papers were presented at PCM 2018, the 12th IIR International Conference on Phase Change Materials and Slurries for Refrigeration and Air Conditioning, held in Orford, Canada, last month. "Investigations on the stability of metallic cans for PCM macro-encapsulation," "Investigation of compatibility of organic and inorganic PCMs with the materials of containers" and "Life cycle assessment phase changes of materials, component and system concept" are among the papers posted on the International Institute of Refrigeration website. 

John Lerch, vice president of sales and marketing at thermal energy storage company Axiom Exergy, writes about "5 things utilities should consider for energy storage." 

Wilmar International said it has ceased sourcing from palm oil suppliers allegedly associated with Gama, a company that was accused by Greenpeace of causing deforestation in Indonesia. 

• The Roundtable on Sustainable Palm Oil and Canadian supply chain consultancy Ulula are collaborating to introduce a mobile phone app to report potential workers’ incidents and abuses on palm oil plantations. 

PCM-equipped personal air conditioner set for commercial release in 2019

Ben Welter - Tuesday, June 26, 2018

Developers of a personal air conditioner designed to reduce energy use in office buildings say they’re on track for commercial release next year. The “μX” micro climate system features a phase change material that solidifies at about 18 degrees C to store cooling generated at night for use during the day.

mX early version
The evolution of the μX: an early design ...
Dr. H. Ezzat Khalifa of Syracuse University led the development team, which includes Air Innovations, Cornell University, United Technologies Research Center and Bush Technical LLC. The team has been working on the system since 2015, funded in large part by a $3.2 million grant from the U.S. Energy Department’s Advanced Research Projects Agency-Energy. The New York State Energy Research and Development Authority provided $400,000 in follow-on funding in 2016.

Sam Brown, OEM custom director at Air Innovations, is in charge of bringing the product to market. He and Michael Wetzel, president and CEO at Air Innovations, talked about their company’s role in the project.

Q: Describe the μX system size, components and functionality.

Brown: “The current unit is about twice size of a standard PC computer tower. The unit utilizes a phase change material that melts over time. We then run a fan over the material to create an active cooling effect. A compressor then re-solidifies the PCM in the off-peak hours for future on-demand needs.”

Q: Describe the phase change material used in the system: type, melt point, thermal storage capacity, amount used in each unit.

Brown:Rubitherm, 68F, 8-10 hours, 40 pounds.”

mX early version
... a version displayed at a recent conference ...
Q: Were different PCMs tested, or did the team focus on one from the start?

Wetzel: “Many PCMs were considered and analyzed before settling on Rubitherm, but no others were tested in operating systems.”

Q: Preliminary tests indicate the prototype can remove more than 32W of heat, surpassing the ARPA-E grant target of 23W. Is the final production model likely to hit that higher number?

Wetzel: “23 watts is the target heat removal directly from a person. Our manikin results showed us exceeding that number in all tests. We tested three different diffuser methods. Some achieved as high as 32 watts removed from the manikin. In all cases we are actually generating more than 500 watt-hours of cooling, enough to cool the airstream 8 degrees F for 10 hours.”

Q: The system is now known as "μX." Will that name be used for the commercial product?

Brown: “No, the commercialized name will more closely reflect the manner in which it's utilized.”

Q: What was the greatest technical hurdle the team faced in developing this product?

Wetzel: “There were many challenges on this project. Part of the program required the development of the world’s smallest scroll compressor. This also means that there was no performance data or design simulation data with which to develop the rest of the system. Our partners on the project had to develop simulation tools based on testing each new component. At Air Innovations our main challenges are designing for manufacturability and the integration and testing of off-the-shelf components as alternatives, as some of the elements of the ARPA-E units are not yet commercially available.”

mX early version
... and, finally, says Brown, "where we think the unit will potentially go in final production."
Q: What is happening with the project right now? Is it at the pilot stage?

Brown: “Currently, we are working through ARPA-E and New York State Energy grants to fully develop the technology. We are developing the unit for two scenarios. The primary is for 8-10 hours of cooling in any office environment. The other is for four hours to off-load the grid in metropolitan areas with peak power capacity concerns. Several units have been built and tested in controlled environments. We are currently seeking grant opportunities to support larger field trials.”

Q: Can you offer any details on the timeline, projected price, target market and sales projections?

Brown: “Further human testing will be necessary in order to right-size the final product. The unit will likely be ready for market sometime in 2019. The initial price point of the unit will be higher, and then come down based on quantity and market demand, settling around $2,500. It is our goal to bring to market 250-500 units in the first year.

“The exciting opportunity with the μX technology is that it further expands upon our existing Micro Environments product line. The commercialized unit will be able to control the users’ complete environment while not only offering active cooling and heating, but to control their entire surroundings as seen in our other models. Furthermore, our customers will see an ROI with the μX technology by allowing set points in the summer to run higher and temps to run cooler in the winter, reducing building HVAC power needs with a more personal temperature control directly at the desk. We believe this technology can improve worker productivity by allowing individual control, at all times, of their specific environment.”

PCM briefing: Neck collar uses Outlast to keep wearer cool; thermally responsive bandage heals wounds quickly

Ben Welter - Monday, June 25, 2018

A new neck collar designed for people living with motor neurone disease features Outlast phase change technology to keep the wearer cool. The Heads Up collar supports the collection of small muscles in the neck that are vulnerable to the wasting effects of the disease.

• A Northwestern University team has developed a thermally responsive bandage that quickly heals painful, hard-to-treat sores in people with diabetes. The bandage features a hydrogel that rapidly solidifies when exposed to body temperature, conforming to the shape of the wound.

• In the short term, analysts say crude palm oil prices have likely hit rock bottom. But a Rabobank analyst is projecting reduced production - and higher prices - from 2022 to 2025. 

•  A call for papers has been issued for the Advanced Automotive Battery Conference Europe, to be held in Strasbourg, France, Jan. 27-31, 2019. "Thermal modeling" and "preventing thermal runaway" are among the topics. The deadline for priority consideration is June 29.

Emily Liu, a professor at Rensselaer Polytechnic Institute, was recently selected by the U.S. Department of Energy's Solar Energy Technologies Office to receive a $1.8 million award to study high-temperature molten-salt properties and corrosion mechanisms.

Dr. Robert Brookins, interim CEO at Alexium International Group Ltd., will present an hourlong webinar, "Phase Change Materials: How Can They Help Set Your Company Apart," on June 28. The free event is sponsored by the Industrial Fabrics Association International.  

• Swedish solar company Azelio has launched a demonstrator of its solar energy storage technology. The system uses an aluminum alloy as a thermal storage material. 

In a new directive, the European Commission is calling for at least 32 percent of total EU energy use to come from renewable sources by 2030. The directive, which will require the formal approval of the European Parliament, sets specific annual targets for cooling and heating installations. 

• The agenda is taking shape for the 13th International Conference on Advanced Building Skins, to be held Oct. 1-2 in Bern, Switzerland. Topics include "Energy buffering with phase change materials" and "Thermal performance of phase change materials for the building skin."

Va-Q-tec AG is expanding its Kölleda location in Thuringia, Germany. The company manufactures vacuum isolation panels, phase change materials and passive thermal packaging systems at two plants there.

• MIT Technology Review reports that Alphabet Inc. (Google's parent company) appears to be in talks to spin out Project Malta, a molten-salt energy storage project, in a transaction involving Breakthrough Energy Ventures, Bill Gates’ $1 billion investment fund.

Patent application: Protective headgear comprising temperature control apparatus

Ben Welter - Monday, June 25, 2018

U.S. patent application 20180160761 (applicant Aspire Zone Foundation, Doha, Qatar):

Protective headgear patent drawing"A protective headgear, such as a hard hat, is provided that comprises a protective outer shell, which surrounds the head of a wearer and in so doing defines a space between the head of the wearer and the underside of the outer shell; a heat-absorbing member; and a forced air ventilation apparatus. In use, the heat-absorbing member is positioned within the outer shell in the space formed between the head of the wearer and the outer shell, so that the forced air ventilation apparatus can provide a flow of ambient air from outside of the outer shell over the heat-absorbing pad within the space between the head of the wearer and the underside of the outer shell, thereby creating a cooling circulation of air around the head and face of the wearer. Suitably, the heat-absorbing pad comprises a phase-change material (PCM)."

Patent application: Heat exchanging thermal liquid container

Ben Welter - Monday, June 25, 2018

Drinkware patent drawingU.S. patent application 20180171197 (assignee Curators of the University of Missouri, Columbia, Mo.):

"A heat exchanging thermal liquid container system that comprises a main body at least partially defining a liquid reservoir structured and operable to retain a liquid, and a phase change material (PCM) liner comprising a PCM liner PCM having a selected melting temperature, and/or at least one PCM pod. Each of the at least one PCM pod(s) comprising a respective PCM pod PCM having a respective selected melting temperature. Wherein the PCM liner and/or the at least one PCM pod are disposable within the liquid reservoir such that when a liquid is disposed within the liquid reservoir the liquid will contact at least one of the PCM liner and the at least one PCM pod such that thermal energy can be exchanged between the liquid and the respective at least one of the PCM liner PCM and the at least one PCM pod PCM."

Related: Drinkware and plateware and active temperature control module for same (Ember Technologies Inc.)

Research roundup: Natural convection heat transfer; simulation of hysteresis effects; PCM in roofs; more

Ben Welter - Wednesday, June 20, 2018

From Energy Conversion and Management:

Effect of using nanoparticles on the performance of thermal energy storage of phase change material coupled with air-conditioning unit
Numerical study on the effect of non-uniform magnetic fields on melting and solidification characteristics of NEPCMs in an annulus enclosure
Solidification behavior of binary eutectic phase change material in a vertical finned thermal storage system dispersed with graphene nano-plates

From International Communications in Heat and Mass Transfer:

A method to evaluate natural convection heat transfer in microencapsulated phase change material (MPCM) slurry: An experimental study
Dynamic of plumes and scaling during the melting of a Phase Change Material heated from below

From Applied Thermal Engineering:

Experimental investigation of the thermal performance of heat pipe assisted phase change material for battery thermal management system
Low-temperature macro-encapsulated phase change material based thermal energy storage system without air void space design

From Energy and Buildings:

Modeling and experimental validation of an algorithm for simulation of hysteresis effects in phase change materials for building components
Thermal performance and numerical simulation of geopolymer concrete containing different types of thermoregulating materials for passive building applications

From Solar Energy:

How to enhance thermal energy storage effect of PCM in roofs with varying solar reflectance: Experimental and numerical assessment of a new roof system for passive cooling in different climate conditions

From Energy:

A facile approach to synthesize microencapsulated phase change materials embedded with silver nanoparticle for both thermal energy storage and antimicrobial purpose

From Reference Module in Materials Science and Materials Engineering:

Materials, Design and Development of Latent Heat Storage Systems for Medium and Large-Scale Applications: Issues and Challenges

From Physica A: Statistical Mechanics and its Applications:

Melting process in porous media around two hot cylinders: Numerical study using the lattice Boltzmann method

From Solar Energy Materials and Solar Cells:

Synthesis and characterization of chain-extended and branched polyurethane copolymers as form stable phase change materials for solar thermal conversion storage

From Construction and Building Materials:

Investigation of different materials for macroencapsulation of salt hydrate phase change materials for building purposes

From Journal of Energy Storage:

CFD thermal energy storage enhancement of PCM filling a cylindrical cavity equipped with submerged heating sources
Performance analysis of industrial PCM heat storage lab prototype