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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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Research roundup: Dynamic behavior of PCM-27; Al2O3, SiO2 and TiO2 nano-inclusions; coacervation microencapsulation; more

Ben Welter - Tuesday, August 14, 2018

From International Journal of Thermal Sciences:

An experimental and a numerical analysis of the dynamic behavior of PCM-27 included inside a vertical enclosure: Application in space heating purposes

From Journal of Molecular Liquids:

Thermal conductivity enhancement in organic phase change material (phenol-water system) upon addition of Al2O3, SiO2 and TiO2 nano-inclusions

From Applied Thermal Engineering:

Experimental and numerical investigations of nano-additives enhanced paraffin in a shell-and-tube heat exchanger: A comparative study
Three-dimensional numerical and experimental investigation of the behavior of solar salts within thermal storage devices during phase change

From Energy Conversion and Management:

Formulation of a model predictive control algorithm to enhance the performance of a latent heat solar thermal system
Performance assessment of a new hydrogen cooled prismatic battery pack arrangement for hydrogen hybrid electric vehicles

From Carbohydrate Polymers:

Chitosan composite microencapsulated comb-like polymeric phase change material via coacervation microencapsulation

From Renewable Energy:

Analytical Considerations on Optimization of Cascaded Heat Transfer Process for Thermal Storage System with Principles of Thermodynamics

From Proceedings of Microscopy & Microanalysis 2018:

In-Situ TEM Observation of Crystallization in Phase-Change Material

From International Journal of Energy Research:

Fraunhofer LBF develops composite PCM to lower dashboard temperature

Ben Welter - Monday, August 13, 2018

Structure of Fraunhofer's Smart Cover Panel.

Researchers at the Fraunhofer Institute for Structural Durability and System Reliability LBF in Darmstadt, Germany, have developed a new phase change composite material designed to reduce the surface temperature of dashboards in vehicles. 

Springer Professional of Germany has a good summary [translated from the German original]:

"The composite is suitable for a temperature phase transition and consists of a carrier material made of polyethylene, which can store energy. The filler graphite, on the other hand, ensures rapid heat dissipation. In a cyclic process of heating and cooling phases, the scientists were able to achieve a temperature reduction of 46 percent or 41 degrees Celsius compared to a conventional polypropylene-talc compound dashboard."

Fraunhofer, of course, offers a more detailed look [also translated from German]:

"To demonstrate the benefits of the new material, the scientists built this component into the dashboard of an electric vehicle to subsequently create a cycle of heating and cooling phases. The cooling was provided by Peltier elements. These electrothermal transducers are in turn cooled by external fans. The energy for Peltier elements and coolers comes from an additional 12 V battery powered by photovoltaic power.

"The energy released during the phase transition was used by the LBF researchers to switch on the Peltier elements only for a certain period of time. In this way, the fans do not have to constantly run at maximum power. By appropriate regulation, the cooling system is coupled to the temperature in the material. This should lead to a higher life expectancy of the electronic components. Thanks to a clever setting of the starting point of the working group, the Smart Cover Panel is controlled by the sunlight itself. This means that cooling only starts in hot summer days, and in winter the coveted warmth stays in the dashboard."

https://www.lbf.fraunhofer.de/de/presse/presseinformationen/phase-changing-material-mehr-komfort-und-reichweite-elektromobilitaet.html

Patent application: Cooling system for vehicle interior surfaces

Ben Welter - Sunday, August 12, 2018

U.S. patent application 20180222517 (applicant Toyota Motor Engineering & Manufacturing North America Inc., Erlanger, Ky.):

"A vehicle component 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. The component also includes a thermally-conductive structure 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."

http://www.freepatentsonline.com/20180222517.pdf

Patent application: Fuel cell freeze protection device and system

Ben Welter - Monday, August 06, 2018

U.S. patent application 20180219237 (applicant Ford Motor Co., Dearborn, Mich.)

"A fuel cell system including a fuel cell stack, a coolant loop and a thermal battery. The coolant loop is configured to flow a coolant liquid therethrough. The thermal battery includes a phase change material configured to absorb heat generated by the fuel cell stack or coolant liquid and to latently store the heat during a first mode of operation the fuel cell system."

http://www.freepatentsonline.com/20180219237.pdf

Related:

Vehicle occupant cooling system (applicant Toyota Motor Engineering & Manufacturing North America Inc., Erlanger, Kentucky)

Solar-powered concept camper uses PCM to keep passengers comfortable

Ben Welter - Monday, July 02, 2018

Dethleffs' e.home concept camperDethleffs GmbH & Co.'s solar-powered concept camper, introduced last year, is one of four winners in the transportation category of the German Innovation Award 2018. The "e.home" features 334 square feet of thin solar panels and a heating system that uses phase change materials to absorb heat when the outside temperature rises above 79° F. Fully equipped, its driving range on a full charge is just over 100 miles.

Christoph Gawalleck, technical director at Dethleffs, oversaw the two-year development of the e-home. He answered a few question via email:

Q: Describe the phase change material used in the vehicle.

A: “The PCM is Micronal from BASF. But BASF sold this business unit to Microtek Laboratories in May 2017. It is a paraffin. The melting point is 26°C, the solidification takes place at 23° C.”

Cross section of PCM panel used in Dethleffs e.homeQ: How is the PCM contained?

A: “The PCM is in aluminum plates that are shaped like corrugated cardboard [right]. So the heat can be passed very quickly to the PCM. The plate contains 4 kilograms of Micronal per square meter.”

Q: How much PCM is used in the camper?

A: “Approximately 35 kilograms.”

Q: Have you collected data on how well the PCM manages temperatures in the camper? Has it met expectations?

A: “The vehicle was at many shows last year, so the tests are still running at the moment.”

Q: What was the development team's great challenge?

A: “The biggest challenge was to get access to the battery capacity of the vehicle in addition to the solar cells.”

Q: Are there plans to commercialize the e.home camper?

A: “The vehicle was meant to present our ideas to customers and match them with their wishes. Of course, various individual elements, such as connectivity, will be incorporated into production vehicles.”

Q: Are there plans to use PCM technology in other Dethleffs campers?

A: “This is not known until the tests have been completed.”

Patent application: System and method of heat management for vehicle

Ben Welter - Monday, June 11, 2018

U.S. patent application 20180156146 (applicants Hyundai Motor Co. and Kia Motors Corp., Seoul, South Korea):

"A system of heat management of a vehicle may include a cooling line in which coolant cooling an engine flows therethrough; an exhaust heat retrieving apparatus for retrieving heat of exhaust gas discharged from a combustion chamber of the engine through operation fluid; a heat storage apparatus which stores heat of exhaust gas retrieved by the exhaust heat retrieving apparatus using the operation fluid and includes phase change material; a coolant heat exchanger in which heat stored in the heat storage apparatus and the coolant are heat-exchanged; a driving information detector for detecting a driving information including a temperature of the coolant and a temperature of the phase change material; and a controller for controlling the temperature of the coolant through the exhaust heat retrieving apparatus or the heat storage apparatus based on the temperature of the coolant and the temperature of the phase change material when the vehicle starts."

http://www.freepatentsonline.com/20180156146.pdf

Related patent applications:

Method and system for exhaust heat recovery (Ford Global Technologies)
HVAC systems for electrically powered vehicles (BorgWarner Inc.)

Patent application: Electric vehicle powered by capacitive energy storage modules

Ben Welter - Wednesday, May 16, 2018

U.S. patent application 20180126857 (applicant: Capacitor Sciences Inc., Menlo Park, Calif.):

"The invention relates to a capacitor based energy storage module and an electric vehicle using the same. For providing an electric vehicle which can meet the requirements of long distance running and rapid acceleration at the same time, the electric vehicle of present invention comprising: An electric control unit controlling all operations of the electric vehicle; An energy storage unit having one or more energy devices based on meta-capacitor which provides needed electric energy of the electric vehicle; A DC-DC converter receiving control signal from said electric control unit to convert the energy from said energy storage unit then provide to motor; A motor converting the electric energy into mechanical energy to drive the wheels; Wheels are driven by the motor to make the electric vehicle run. ... [The] capacitive energy storage module may include a cooling mechanism in thermal contact with the capacitive energy storage device and/or the DC-voltage converter. Such a cooling mechanism may be, e.g., a passive cooling mechanism, an active cooling system using air, water, ethylene glycol as a coolant; phase-change material, or any combination thereof."

http://www.freepatentsonline.com/20180126857.pdf

Patent application: Thermal management system for fuel cell vehicle

Ben Welter - Tuesday, May 01, 2018

U.S. patent application 20180114998 (applicant Hyundai Motor Co., Seoul, South Korea):

"A thermal management system for a fuel cell vehicle includes a first line including a coolant pump and a fuel cell stack, a second line including a coolant heater and a phase change material (PCM) and connected to the first line to form a first loop in which the coolant pump, the stack, the coolant heater, and the PCM are arranged, a third line including a radiator and connected to the first line to form a second loop in which the coolant pump, the stack, and the radiator are arranged, and an opening and closing valve opening and closing each of the first line, the second line, and the third line to allow the coolant to circulate in at least one of the first loop and the second loop, wherein the PCM is configured to be heat-exchanged with the coolant heater and the coolant."

http://www.freepatentsonline.com/20180114998.pdf

PCM keeps Embry-Riddle’s EcoCAR entry running cool

Ben Welter - Monday, April 30, 2018

Batteries used in hybrid and electric cars work hard and run hot. Traditional cooling systems use an array of pumps, heat exchangers, cooling fans and hoses to manage that heat. Florida’s Embry-Riddle Aeronautical University needed something lighter and simpler for its entry in the Department of Energy’s EcoCAR 3 competition.

The solution: an aluminum cooling plate filled with biobased phase change material.

A team of mechanical engineering students at the school designed and built the plate under the direction of Sandra Boetcher, associate professor of mechanical engineering.

The school’s EcoCAR entry required that the plate use a PCM with a peak melting point of 45 degrees Celsius (113 degrees F). To achieve that temperature, the team selected two commercially available PCMs – PureTemp 37 and PureTemp 48 – and mixed them together.

Embry-Riddle cold plateBoetcher explains the photo at right:

“That’s the inside of the plate before we sealed the aluminum lid on it. On the inside is a copper tube. At the time we put this in the car, we were under a strict deadline and did not have time to redo the bending of the copper tube. The copper tube feeds a cold ethylene-glycol/water mixture as backup for when the PCM has completely melted and needs to resolidify while the car is driving.

“I was concerned that the copper tube didn’t provide enough coverage of the area, but that cold plate has been in the car for the past 2.5 years and it works great. Actually, the back-up pump that runs the ethylene-glycol/water through the copper tube rarely even turns on which means that under our test-driving conditions, the cold plate is acting 100 percent passive. The terrible part of the PCM is that it loves to leak. We feel that there has been some leaking.”

The plate is lighter and simpler than a water-cooled system. “It doesn’t take any energy to run,” said Patrick Currier, an associate professor who advises the EcoCAR team. “We’re not wasting power cooling things. This is a totally passive system, so unless it leaks, it can’t fail.”

Embry-Riddle filed for a U.S. patent on the device in 2015.

“The diagrams in the patent are similar to what we have in the EcoCAR right now, although the geometry is a little different,” Boetcher said. “The research we are conducting is still on-going. The applications we envision could be anything that requires PCM – battery cooling, building technologies, etc.”

Embry-Riddle is one of 16 North American universities challenged to redesign a 2016 Chevrolet Camaro into a hybrid-electric car to reduce environmental impact, while maintaining the “muscle and performance” the car is known for. 

The teams have had four years to develop their entries. The cars will be put to the test in a variety of events in Arizona and California in May. Winners will be chosen in 40-plus categories at an awards ceremony in Hollywood on May 22, with more than $100,000 in prize money at stake.

Embry-Riddle EcoCAR entry

https://news.erau.edu/headlines/shape-shifters-lightweight-technology-keeps-batteries-cool-supporting-eco-vehicles

Patent application: Tube with a reservoir of PCM for a heat exchanger

Ben Welter - Monday, April 23, 2018

U.S. patent application 20180106555 (applicant Valeo Systemes Thermiques, Le Mesnil Saint-Denis, France):

Valeo patent drawing"A tube with a reservoir of phase-change material [1] for a heat exchange bundle of a heat exchanger, said tube with a reservoir of phase-change material comprising: two flow plates [3] configured to be assembled with one another in a sealed manner and to form at least one conduit in which a first heat transfer fluid flows; at least one reservoir plate, said reservoir plate being configured to be assembled in a sealed manner onto an external face of one of the two flow plates so as to form housings for the phase-change material; and a filling duct for the phase-change material, one end of said filling duct opening into one of the edges of said tube with a reservoir of phase-change material, said filling duct being formed by a filling spout of the reservoir plate towards the outside and by the external face of one of the two flow plates, said filling duct further comprising a plug, said filling duct and said plug being contained within a volume of width smaller than or equal to the width of the tube with a reservoir of phase-change material and of height less than or equal to the height of the housings of the phase-change material."

http://www.freepatentsonline.com/20180106555.pdf