The Phase Change Matters e-mail newsletter is a weekly summary of the latest news and research on phase change materials and thermal energy storage. To subscribe, visit www.puretemp.com/subscribe. For more frequent updates, follow @puretemp on Twitter or visit the Phase Change Matters blog, www.puretemp.com/pcmatters.
MANUFACTURING
RAL members are encouraged to spread the word on quality standards
One of the challenges faced by PCM manufacturers is a negative perception of the material fed by occasional reports of PCM systems that do not perform as well as expected. To address that concern, the RAL Quality Association PCM is recommending that member companies inform potential customers about the performance standards established by RAL. Potential customers may not be aware that such standards exist.
While RAL certification of PCM products and systems is available, the objective of the RAL recommendation is not to suggest to customers that RAL certification is required, but rather to increase awareness that standards exist to distinguish between good and bad quality products.
An excerpt from the association’s letter to members:
“The Quality Association PCM (Gütegemeinschaft PCM e.V.) was founded to develop meaningful and transparent quality specifications for phase change materials, monitor compliance with these specifications and award the RAL Quality Mark Phase Change Materials to those products that do comply. The overall objective is to build up customer confidence in phase change materials and to make sure that the products live up to the customers’ expectations with regards to performance and longevity. …
“In order to achieve full customer satisfaction and raise confidence in our technology, we recommend pointing to the criteria laid down in Quality Assurance RAL-GZ 896 whenever you participate in a tender or talk to potential clients. It is the customers´ decision if they want to apply these criteria, but they should be aware of them at least. The latest version of RAL-GZ 896 is available to the public on our website (https://www.pcm-ral.org/pcm/en/quality-testing-specifications-pcm/).”
The RAL Quality Association PCM was established in 2004 to develop standards for the PCM industry. Members include Axiotherm, Microtek Laboratories, Rubitherm, Croda Europe, va-Q-tec, PCM Technology, Global-Systems Europe, Sasol, Sunamp, Pluss Advanced Technologies and PureTemp LLC. The association will hold its next meeting Nov. 5 in Dusseldorf, Germany.
NEW PRODUCTS
New adaptek panels, pouches cover temperature range from 6°C to 43°C
Microtek Laboratories Inc. of Dayton, Ohio, recently introduced a new line of PCM-equipped pouches and panels for use in temperature-controlled shipping. Tim Riazzi, Microtek president, answered a few questions about the adaptek line by email.
Q: What prompted the decision to develop the adaptek pouches and panels?
A: “Because we are at the forefront of thermal management solutions and have the ability to control thermal energy for a variety of applications, we were regularly approached about developing new and different ways to provide thermal management in other forms and for new industries. As manufacturers continue to introduce innovative new products, we feel it is imperative that logistics keeps pace to ensure their safe and affordable delivery. In response, we created adaptek panels and pouches, to further enhance and extend temperature management and control.”
Q: What types of PCM are used?
A: “Depending on the application, we are incorporating both alkanes and methyl esters in the adaptek panels and pouches as well as a wide range of temperatures from 6°C to 43°C.
Q: What materials are used to contain the PCM?
A: “At this time our processes and materials are proprietary, and we are treating them as a trade secret.”
Q: When were the products officially launched?
A: “The initial launch our panels was at the end of Q3 2018 and the launch of our pouches was Q1 of this year. The full line of the adaptek panels and pouches were not fully a full commercialized until the end of Q2 of this year.”
Q: What applications/markets are the pouches aimed at?
A: “Currently both adaptek lines are mostly being used in the pharmaceutical and life sciences industries, but we have had interest from a wide variety of industries.”
Q: Have you received inquiries for unexpected uses, such as transporting high-value chocolates or cheese?
A: “We have had a lot of interest from a diverse group of companies covering a wide variety of industries, but because of non-disclosure agreements we cannot give any specifics.”
Q: Are you selling these mostly in bulk to large customers — or to a mix of large-, medium- and small companies and individual consumers?
A: “We have not had much interest from individuals, but the inquiries have come from companies has come from a mix of large, medium, and small companies. It has been very exciting to see interest from such a wide variety of companies and industries.”
Q: Do you have plans to seek RAL certification for the products?
A: “I would say no.”
PATENTS
Heat battery assemblies and monitoring systems therefor
U.S. patent application 20190316851 (applicant Sunamp Ltd., Edinburgh, Scotland):
“There are herein described energy storage systems. More particularly there are provided thermal energy storage systems comprising battery assemblies containing phase change materials and a monitoring system therefor. In addition there are provided thermal stores comprising battery assemblies having integral control means for management of the thermal energy provided by the battery assembly.”
Cooling electronic devices in a data center
U.S. patent application 20190327859 (applicant Google LLC, Mountain View, Calif.):
“A server tray package includes a motherboard assembly that includes a plurality of data center electronic devices, the plurality of data center electronic devices including at least one heat generating processor device; and a liquid cold plate assembly. The liquid cold plate assembly includes a base portion mounted to the motherboard assembly, the base portion and motherboard assembly defining a volume that at least partially encloses the plurality of data center electronic devices; and a top portion mounted to the base portion and including a heat transfer member shaped to thermally contact the heat generating processor device, the heat transfer member including an inlet port and an outlet port that are in fluid communication with a cooling liquid flow path defined through the heat transfer member.”
Cooling systems for vehicle interior surfaces
U.S. patent application 20190322305 (applicant Toyota Motor Engineering & Manufacturing North America Inc., Plano, Texas):
“A vehicle steering wheel includes a first volume of phase change material and a second volume of phase change material spaced apart from the first volume of phase change material. The first volume of phase change material contains a greater mass of phase change material than the second volume of phase change material. A first wall forms a rim of the steering wheel. The first wall is in direct contact with both the first volume of phase change material and the second volume of phase change material, so as to facilitate heat transfer between the first volume of phase change material and the second volume of phase change material.”
Fluid for reinforcing clinical wrap
U.S. patent application 20190321217 (applicant Stryker Corp., Kalamazoo, Mich.):
“A reinforcing clinical wrap is provided with integral thermal management. The clinical wrap includes a fluid circuit for a heat transfer medium to circulate between a fluid inlet and a fluid outlet. A shape conforming medium is disposed within a portion of the clinical wrap providing selective reinforcement support of the portion of the clinical wrap to conform to a surface of a patient. Non-limiting examples of the shape conforming medium may include … a phase change material.”
Aqueous polyurethane microgel dispersion
U.S. patent application 20190322879 (applicant Encapsys LLC, Appleton, Wis.):
“The invention describes a method of forming a stable aqueous polyurethane microgel dispersion comprising preparing an oil phase comprising a gel-forming polyol and an isocyanate in approximately stoichiometric proportion by blending the polyol and isocyanate for a time, less than the gel time of the polyol and isocyanate, thereby forming a homogeneous flowable liquid mixture; providing a water phase comprising a surfactant dispersed in water; combining the water phase with the oil phase flowable liquid mixture and subjecting the combined water and oil phases to high shear agitation to form an aqueous emulsion of micro-size droplets of the oil phase flowable mixture in water; and agitating the emulsion for a time sufficient for the micro-size droplets to polymerize, forming a stable aqueous suspension of solid polyurethane micro-size gel particles.”
Athletic activity monitoring device with energy capture
U.S. patent application 20190319067 (applicant Nike Inc., Beaverton, Ore.):
“Aspects relate to an energy harvesting device adapted for use by an athlete while exercising. The device may utilize a mass of phase-change material to store heat energy, the stored heat energy subsequently converted into electrical energy by one or more thermoelectric generator modules. The energy harvesting device may be integrated into an item of clothing, and such that the mass of phase change material may store heat energy as the item of clothing is laundered.”
Cold-crystallizing material and method
U.S. patent application 20190316017 (applicant Aalto University Foundation, Aalto, Finland):
“The present invention relates to a cold-crystallizing material having high latent heat, and a method of using the present material for heat storing. The material of the invention comprises of a phase change material and an additive which is preferably a hydrophilic polymer matrix. Preferably, sugar alcohols, such as erythritol or D-mannitol, are used as the phase change material. The polymer of the invention is preferably cross-linked and ionic, i.e. a polyelectrolyte. PCM stores a high amount of heat energy while melting and releases the stored thermal energy by cold-crystallization. Compared to previously studied cold-crystallizing materials, the latent heat of the cold-crystallizing material of the invention is considerably higher, and cold-crystallization is more repeatable in successive melting-crystallization cycles.”
IN BRIEF
• Cranfield University of Cranfield, United Kingdom, has been using a PCM-based heat storage system since March. Marton Geotechnical Services, the U.K. company behind the technology, now plans to commercialize it. Peter Harris, the company’s business development manager, thinks the modular 75kWh systems can be on the market by early 2020.
• Australia’s University of the Sunshine Coast and resource management company Veolia won the Out of the Box category of the Global District Energy Climate Awards last week for a “water battery” featuring 6,000 solar panels and a thermal energy storage tank. The system has cut grid energy on the campus by 40 percent.
• Emirates Central Cooling Systems Corp. (Empower) has begun construction of a new district cooling plant in Dubai. The 47,000 refrigeration ton system includes two thermal energy storage units designed to optimize on- and off-peak energy use.
RESEARCH ROUNDUP
For our full list of recent academic research, see puretemp.com/academic. Here are highlights from the past week:
From Renewable Energy:• An experimental evaluation of thermal behavior of the building envelope using macroencapsulated pcm for energy savings
• Experimental and numerical research on development of synthetic heat storage form incorporating phase change materials to protect concrete in cold weather
• Discharge of a composite metal foam/phase change material to air heat exchanger for a domestic thermal storage unit
From Applied Energy:
• Solidification enhancement with multiple PCMs, cascaded metal foam and nanoparticles in the shell-and-tube energy storage system
From International Journal of Heat and Mass Transfer:
• Experimental study on the thermal behavior of RT-35HC paraffin within copper and Iron-Nickel open cell foams: Energy storage for thermal management of electronics
From Construction and Building Materials:
• Sustainable polymer-based Phase Change Materials for energy efficiency in buildings and their application in aerial lime mortars
From Journal of Cleaner Production:
• Experimental investigation on improvement of latent heat and thermal conductivity of shape-stable phase-change materials using modified fly ash
From Journal of Energy Storage:
• Transient modeling for the prediction of the temperature distribution with phase change material in a salt-gradient solar pond and comparison with experimental data
• Augmenting the productivity of solar still using multiple PCMs as heat energy storage
From IOP Conference Series: Materials Science and Engineering:
• Cementitious plasters for façade finishing with phase change materials and thermochromic pigments
• Analysis of the energy and thermal performance of a radiant cooling panel system with integrated phase change materials in very hot and humid conditions
• The utilization rate of potential heat accumulation capabilities using latent heat of phase-change materials
From Materials & Design:
• Multiple-Criteria Decision Analysis and characterisation of phase change materials for waste heat recovery at high temperature for sustainable energy-intensive industry
From Thermochimica Acta:
• Using co-electrospinning method to regulate phase change temperatures of fatty acid eutectic/polystyrene/fatty acid eutectic form-stable phase change composite nanofibrous membranes for thermal energy storage
From Applied Thermal Engineering:
• Discharging performance enhancement of a phase change material based thermal energy storage device for transport air-conditioning applications
• PCM integrated to external building walls: An optimization study on maximum activation of latent heat
• Thermal performance evaluation of glass window combining silica aerogels and phase change materials for cold climate of China
From Solar Energy Materials and Solar Cells:
• Preparation and characterization of poly (N-methylol acrylamide)/polyethylene glycol composite phase change materials for thermal energy storage
• Enhanced thermal performance of phase change material stabilized with textile-structured carbon scaffolds
• Design of 3D-network montmorillonite nanosheet/stearic acid shape-stabilized phase change materials for solar energy storage
From Minerals:
• Fabrication and Thermal Properties of Capric Acid/Calcinated Iron Tailings/Carbon Nanotubes Composite as Form-Stable Phase Change Materials for Thermal Energy Storage
NETWORKING
Connect with PCM experts and industry leaders on LinkedIn
More than 1,500 people have joined a LinkedIn group devoted to the discussion of phase change material and thermal energy storage. The Phase Change Matters group is an interactive complement to the award-winning blog and newsletter of the same name.
You are invited to join the group and connect with PCM and TES experts from around the world. This month we welcome Alex Keeling, sales and marketing director, Europe, Africa and Middle East, Exam Cold Chain Solutions, Buckingham, United Kingdom; Patricio Cabo, CEO at EQM Solutions, Mar del Plata, Argentina; Lim San Teng, senior manager, Green Building Policy Department, ESG Group, Singapore; Mirko Liberati, production manager at RDC srl, Perugia, Italy; Rama Kotapally, founder at TSilicon,
Bengaluru, India; Sathyanarayanan Subramanian, mechanical/thermal engineer, Roanoke, Va.; Fredrik Lothigius, account manager at Climator Sweden, Skövde, Sweden; Joel Tetlow, managing director at The Uk Energy Guys, Blackburn, United Kingdom; and Paula Rahm, student at Carleton University, Ontario, Canada.