Experimental evaluation at pilot plant scale of multiple PCMs (cascaded) vs. single PCM configuration for thermal energy storage

摘要

The present paper provides on one hand, a literature review of the different studies available in thescientific literature where the concept of multiple phase change materials (PCM) configuration, alsonamed cascaded or multi-stage, has been presented and on the other hand, an experimental evaluationof the advantages of using the multiple PCM configuration instead of the single PCM configuration inthermal energy storage (TES) systems at pilot plant to fill the gap of experimental and high scales studieson this concept in the literature. Two PCM with melting temperatures in a temperature range of 150e200 C were selected due to their high value of heat of fusion and compared: d-mannitol and hydroquinone.Three configurations were evaluated: (1) single PCM with hydroquinone, (2) single PCM with dmannitoland (3) multiple PCM with hydroquinone and d-mannitol. A discussion regarding the results onthe specific energy stored and effectiveness as well as the evolution of the PCM and heat transfer fluid(HTF) through the time and at different and representative locations of the facility is presented. Resultsshowed that the multiple PCMs configuration introduced an effectiveness enhancement of 19.36% ifcompared with single PCM configuration as well as a higher uniformity on the HTF temperature differencebetween the inlet and outlet.