A novel cascade latent heat thermal energy storage system consisting of erythritol and paraffin wax for deep recovery of medium-temperature industrial waste heat

Yang S., Shao X., Luo J., Baghaei Oskouei S., Bayer Ö., Fan L.

ENERGY, vol.265, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 265
  • Publication Date: 2023
  • Doi Number: 10.1016/j.energy.2022.126359
  • Journal Name: ENERGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Applied Science & Technology Source, Aquatic Science & Fisheries Abstracts (ASFA), CAB Abstracts, Communication Abstracts, Compendex, Computer & Applied Sciences, Environment Index, INSPEC, Metadex, Pollution Abstracts, Public Affairs Index, Veterinary Science Database, Civil Engineering Abstracts
  • Keywords: Cascade latent heat thermal energy storage, Erythritol, Medium temperature, Paraffin wax, Waste heat recovery
  • Middle East Technical University Affiliated: Yes


Recovering medium-temperature (e.g., 150-180 degrees C) industrial waste heat through latent heat thermal energy storage (LHTES) can effectively attenuate the consumption of fossil fuels. However, the LHTES system containing a single medium-temperature phase change material (PCM), e.g., erythritol, cannot absorb the part of heat below the PCM's melting point (-118 degrees C) during the charging process. Meanwhile, a single low-temperature PCM, e.g., paraffin wax, is unable to supply a significant amount of heat at temperatures higher than its melting point upon discharging. Therefore, a cascade LHTES system combining one erythritol unit and two paraffin wax units (melting point of-60 degrees C) was proposed to deeply recover the waste heat during charging and increase the heat supply temperature during discharging. Through prototype testing, the performance of such a cascade system was examined under various working conditions. It was shown that the cascade system could improve the ef-ficiency of the waste heat recovery from 15.8% to 63.4% under the charging condition of 100 L/h and 160 degrees C, as compared to a single-stage erythritol-based system. The average heat supply temperature of the cascade system was also increased from 37 degrees C (at a constant flow rate) to 53.6 degrees C via an active discharging strategy (by tuning the flow rate). This highly efficient cascade LHTES system has great potential for recovery of medium -temperature waste heat towards a decarbonized future of space heating for buildings.