Multistage Latent Heat Cold Thermal Energy Storage Design Analysis
2013 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 112, no SI, 1438-1445 p.Article in journal (Refereed) Published
Thermal energy storage in cooling applications contributes to improvements in overall system efficiency as well as to better energy quality management. Latent heat thermal energy storage (LHTES) is used to provide load shifted thermal energy at small temperature swing with high storage density, hence an overall more compact energy system. However, the low thermal conductivity of the majority of the phase change materials (PCMs) necessitates delicate design of the active storage unit to meet power demand (high enough energy extraction/storage per amount of time).
A performance analysis of two LHTES configurations is carried out in this work. Thermal charge and discharge rate of single PCM is compared with multistage LHTES using a cascade design of multiple PCMs at various phase change temperatures in a submerged finned pipe heat exchanger design. The work is conducted with a validated finite element based numerical simulation for evaluation of both full charge/discharge cycle and continuous half charge/discharge cycles.
The results show that in full charge/discharge mode, the thermal performance of a multi-PCM LHTES may be improved by 10% to 40% as compared to that of a homogeneous single-PCM storage unit in terms of thermal charge/discharge rate. This is due to the capability of the multistage LHTES to maintain a higher driving temperature difference for the heat transfer process in the charging and discharging processes. In half charge/discharge cycling mode, however, the thermal power rating performance of multi-PCM storage converges towards that of the single-PCM storage in melting process, reducing thus the multi-PCM enhancement. This work provides preliminary insights to multistage latent heat cold thermal energy storage design with finned pipe heat exchanger.
Place, publisher, year, edition, pages
2013. Vol. 112, no SI, 1438-1445 p.
Thermal energy storage, Phase change material, Multistage storage design
Energy Engineering Energy Systems
IdentifiersURN: urn:nbn:se:kth:diva-117698DOI: 10.1016/j.apenergy.2013.01.054ISI: 000329377800156ScopusID: 2-s2.0-84884210408OAI: oai:DiVA.org:kth-117698DiVA: diva2:602620
4th International Conference on Applied Energy (ICAE),July 01-04, 2012, Suzhou, China
QC 201402102013-02-012013-02-012014-02-10Bibliographically approved