CIESC Journal ›› 2021, Vol. 72 ›› Issue (5): 2763-2772.DOI: 10.11949/0438-1157.20201484

• Energy and environmental engineering • Previous Articles     Next Articles

Performance test and numerical study of salt hydrate-based thermochemical heat storage materials at middle-low temperature

LI Wei(),WANG Qiuwang,ZENG Min()   

  1. Key Laboratory of Thermo-Fluid Science and Engineering, Ministry of Education, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, China
  • Received:2020-10-26 Revised:2020-12-02 Online:2021-05-05 Published:2021-05-05
  • Contact: ZENG Min

水合盐基中低温热化学储热材料性能测试及数值研究

李威(),王秋旺,曾敏()   

  1. 西安交通大学能源与动力工程学院,热流科学与工程教育部重点实验室,陕西 西安 710049
  • 通讯作者: 曾敏
  • 作者简介:李威(1993—),男,博士研究生,limingwei93@163.com
  • 基金资助:
    国家自然科学基金面上项目(51776157);中央高校基础研究经费(xzy022020024)

Abstract:

Using hydrated salt K2CO3·1.5H2O and expanded graphite (EG) as chemical heat storage materials and porous matrix respectively, a composite heat storage adsorbent K2CO3@EG was developed. The desorption, adsorption performance and cycle stability of the composite sorbent and pure salt without EG-doping were compared and analyzed. The results show that the desorption temperature of the composite adsorbent is reduced, and the adsorption kinetics of adsorbate is obviously improved, which can effectively avoid deliquescence. After fifteen consecutive desorption-hydration cycle experiments, the heat storage density of pure salt and composite adsorbent decreased by 27.6% and 10.9%, respectively. In addition, the numerical results of the thermal storage unit preliminarily verify the feasibility of the thermal storage system.

Key words: salt-hydrate, thermochemical heat storage, composite sorbent, kinetics, heat transfer, energy storage density, cycle stability

摘要:

以水合盐K2CO3·1.5H2O和膨胀石墨(EG)分别作为化学蓄热材料和多孔基质,研制了复合储热吸附剂K2CO3@EG。对该复合吸附剂和未掺杂膨胀石墨的纯水合盐就脱附储热、吸附性能、循环稳定性等方面进行了对比分析。结果表明,复合吸附剂所需的脱附温度降低,对吸附质的吸附动力学性能也有明显提升且可有效避免潮解现象。经过连续15次的脱附-水合循环实验后,纯盐和复合吸附剂的储热密度分别下降27.6%和10.9%。此外,对储热单元的数值研究结果初步验证了该蓄热体系的可行性。

关键词: 水合盐, 热化学储热, 复合吸附剂, 动力学, 传热, 储热密度, 循环稳定性

CLC Number: