Title :

Performance comparison of two PCM candidates for new concept of compact thermal storage in solar DHW systems

Author(s) :

Fraisse, Gilles [Auteur]
LabOratoire proCédés énergIe bâtimEnt [LOCIE]
Thonon, Maxime [Auteur]
LabOratoire proCédés énergIe bâtimEnt [LOCIE]
Zalewski, Laurent [Auteur]
Laboratoire de Génie Civil et Géo-Environnement (LGCgE) - ULR 4515 [LGCgE]
Leconte, Antoine [Auteur]
Institut National de L'Energie Solaire [INES]
Francois, Eric [Auteur]
Institut National de L'Energie Solaire [INES]
Pailha, Mickael [Auteur]
LabOratoire proCédés énergIe bâtimEnt [LOCIE]
Cloet, David [Auteur]
LabOratoire proCédés énergIe bâtimEnt [LOCIE]
Moracchioli, Robert [Auteur]
Dynamique et Action Territoriales et Environnementales [DATE]
Traonvouez, Luc [Auteur]
Franquet, Erwin [Auteur]
Laboratoire de Polytech Nice-Sophia [Polytech'Lab]

Journal title :

Journal of Energy Storage

Pages :

111198

Publisher :

Elsevier

Publication date :

2024

ISSN :

2352-152X

HAL domain(s) :

Sciences de l'ingénieur [physics]/Autre

English abstract : [en]

The latent heat of phase change allows to increase the energy density compared tosensible storage. In the building sector, it is possible to replace hot water tanks that arebulky due to their cylindrical shape, by smaller ...
Show more >The latent heat of phase change allows to increase the energy density compared tosensible storage. In the building sector, it is possible to replace hot water tanks that arebulky due to their cylindrical shape, by smaller storage volume and parallelepipedgeometry. The idea of the new concept is thus to propose a hybrid and modularstorage component with a cavity containing the phase change material (PCM)delimited by two flat heat exchangers connected by slotted fins. The first step was toprecisely characterize the behavior of the two selected PCMs during melting andsolidification, without and with supercooling (respectively RT58 and PEG6000). Thenext step concerns the modeling of the storage cavity and then the optimization of thenew full-size concept for solar domestic hot water systems. A prototype wasexperimentally tested for the two PCMs under real operating conditions with a reducedsequence of six days allowing the annual performance to be calculated.The experimental results confirm the known limit of PCM concerning its low thermalconductivity, which can penalize the power extracted from the storage duringcontinuous withdrawals. The spacing of the fins thus plays a major role in heat transfer.The evaluation of the annual performances carried out on the prototype shows that thesolar fraction is quite satisfactory, between 40 and 90% depending on the climate inFrance. The distribution of average temperatures observed within the PCM is directlycorrelated with the melting ranges. The RT58 is thus penalized compared to thePEG6000 because the start of the melting takes place at a much lower level (30°Cagainst 52°C), which can lead to more frequent use of back-up. Regarding heatstorage, the much lower density of the RT58 explains the difference in energy stored inthe prototype (+34% for the PEG6000 between 20 and 80°C) knowing that the latentheat and the specific heat are of the same order of magnitude in both cases. Finally,the higher thermal conductivity of PEG6000 favors the heat rate exchanged during thestorage charging and discharging phases.Show less >

Language :

Anglais

Popular science :

Non

ANR Project :

Echangeur stockeur ultra-compact à changement de phase

Collections :

• Laboratoire Génie Civil et géo-Environnement (LGCgE) - ULR 4515

Source :

Harvested from HAL