Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Paraffins to cut energy consumption in homes

24.09.2014

UPV/EHU-University of the Basque Country researchers develop a compact heat storage prototype that can be easily fitted in buildings

40% of the total consumption of energy in Europe takes place in buildings, so reducing this consumption is becoming increasingly important. Integrating renewables into the energy supply for buildings is a further step towards moving towards this aim.


View of the thermal energy storage prototype

The UPV/EHU research group ENEDI has developed a modular device based on paraffins that allows thermal energy to be stored, thus reducing the total volume of the system by 50% with respect to storage by means of water, traditionally used in buildings.

Thermal energy storage is a common strategy in energy production systems in which the period of production does not coincide with that of consumption. This happens with the production of hot water by means of solar thermal panels, for example; here, hot water is produced during sunlight hours when demand is lower.

It is also the case in residential cogeneration, where heat and electrical power are simultaneously generated but not so demand. In both cases, storing the heat allows production to be decoupled from demand, thus making the integration of these technologies into buildings more flexible. Here, it is normal for periods of energy production not to coincide with those when it is consumed.

Water tanks have been traditionally used to store heat. "They work well," explained Álvaro Campos, a researcher on the project, "and water is very cheap, but large volumes are needed to achieve significant heat storage, which restricts their integration into homes, where the availability of space is very limited."

The UPV/EHU research group ENEDI has developed a prototype with 50% less volume and more flexible in terms of design; it has a prismatic shape, is easy to integrate into buildings and offers optimum use of space. What is more, its modular nature allows the design to be easily changed.

The system is based on the use of latent heat from the solid-liquid phase change of materials known as PCMs (Phase Change Materials). "When we heat these materials they have the capacity, once they reach their phase change temperature, to start changing their state; and by keeping the temperature practically constant, they allow a very high quantity of energy to be stored; that way, we can achieve much greater energy density with smaller heat losses into the atmosphere," explained Campos.

The device uses a commercial paraffin that melts at around 60 ºC. "It is very stable and has a long service life," pointed out Campos.  The paraffin is encapsulated inside aluminium plates which are arranged in such a way that channels are formed between them.

The thermal loading and unloading process is carried out by making water circulate through these channels, so the hot water yields heat to the plates during the loading process and melts the encapsulated material; conversely, cold water is made to circulate through the channels so that the stored heat is recovered and the paraffin solidifies. Campos' proposal solves one of the problems of PCMs which, owing to their low thermal conductivity, tend to take a very long time to yield the heat they have accumulated. "Our design is based on very thin metal plates which allow the heat to be extracted at a speed similar to that of water tanks," he concluded.

According to Campos, one of the most attractive aspects of the system lies in its compact, modular nature. Water tanks need to be cylindrical and slim (tall and thin) if they are to function optimally. "We can achieve much more compact, prismatic shapes that can be fitted into any corner, even inside a false ceiling," he remarked. "All this makes our proposal more than just an alternative to the water tank, because it offers the possibility of fitting a device for storing thermal energy in places and in applications where, owing to a lack of space, the fitting of a water tank may not be feasible," added Campos.

Right now, work is being done to build a full-scale prototype that will be integrated into an experimental facility of the Quality Control in Building Lab (LCCE) of the Government of the Basque Autonomous Community, "to study how the equipment responds under actual operating conditions".

Campos is optimistic about the competitiveness of the device. "We have something that could offer sufficient technical advantages as it is an attractive proposal irrespective of the final price." The group is already working on other potential PCMs that allow greater storage capacity and are cheaper; they include fatty acids and other organic materials.

Additional information
Alvaro Campos-Celador is a Doctor of Engineering, researcher and lecturer at the UPV/EHU-University of the Basque Country and member of the university's consolidated research group ENEDI (Energy in Building). The team is led by Jose María Sala-Lizarraga, Professor of Thermodynamics in the UPV/EHU's Department of Thermal Machines and Engines at the Faculty of Engineering in Bilbao. The research was mainly conducted at the UPV/EHU's University School of Mining and Public Works Engineering and at the Quality Control in Building Lab of the Government of the Basque Autonomous Community, where the Thermal Area is currently being led by ENEDI. This research is registered within the microTES project (ENE2012-38633-C03), in which the University of Oviedo and the University of La Rioja are also participating.

References
1. A. Campos-Celador, G. Diarce, J. Terés-Zubiaga, T. Bandos, A. García-Romero, L.M. López, J.M. Sala, Design of a Finned Plate Latent Heat Thermal Energy Storage System for Domestic Applications, Energy Procedia, 48 (2014) 300-308.
2. Campos-Celador, G. Diarce, I. González-Pino, J.M. Sala, Development and comparative analysis of the modeling of an innovative finned-plate latent heat thermal energy storage system, Energy, 58 (2013) 438-447.

Patents
As a result of this research, an international patent is currently being applied for: Modular latent thermal storage unit (WO 2014016456 A1)
Inventors: ÁLVARO CAMPOS CELADOR, JOSÉ MARÍA SALA LIZARRAGA, LUIS ALFONSO DEL PORTILLO VALDÉS. http://www.google.com/patents/WO2014016456A1?cl=es

Matxalen Sotillo | Eurek Alert!
Further information:
http://www.ehu.es/

More articles from Power and Electrical Engineering:

nachricht Laser sensor LAH-G1 - optical distance sensors with measurement value display
15.08.2017 | WayCon Positionsmesstechnik GmbH

nachricht Engineers find better way to detect nanoparticles
14.08.2017 | Washington University in St. Louis

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

NASA Protects its super heroes from space weather

17.08.2017 | Physics and Astronomy

Spray-on electric rainbows: Making safer electrochromic inks

17.08.2017 | Materials Sciences

Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

17.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>