Abstract:

In order for efficient chemisorption heat storage system, an activated carbon fiber (ACF)-LiCl composite sorbent was developed while silica sol (SS) was used for shaping. Morphologies records, sorption kinetics and heat storage performance of ACF-LiCl composite sorbent were investigated. Samples with different salt contents were fabricated to store low-temperature thermal heat by impregnation methods. According to the test of the solution leakage phenomenon, the best sample was determined to be ACFLi30. Through the experimental study, thermal conductivity, specific surface area, pore volume and pore diameter were obtained. Sorption kinetics and equilibrium sorption capacity under conditions of multi temperature and relative humidity were studied by utilizing constant temperature and humidity chamber. The water uptake of ACFLi30 sample can be up to 1.1 g/g. Energy storage density was measured by simultaneous thermal analyzer. ACFLi30 sample had the good energy storage performance with 1.08 kW·h/kg mass energy storage density and 588.2 kW·h/m³ volumetric energy storage density. Compared with expanded vermiculite and activated alumina matrix, composite sorbent with ACF matrix has advantage in volumetric energy storage density. As a consequence, ACF-LiCl is promising sorbent in the field of chemisorption heat storage.

Key words: activated carbon fiber, sorbent, lithium chloride, adsorption, desorption, heat storage

摘要：

研制了一种以活性碳纤维毡为基质、氯化锂（LiCl）为吸湿盐的复合吸附剂，并辅以硅溶胶进行固化成型。该复合吸附剂可用于以水为吸附质的热化学吸附储热系统，并对其微观结构、吸附性能和储热性能进行了表征研究。制备了不同含盐量的复合吸附剂样品，并根据样品的溶液泄漏现象，确定ACFLi30为最佳样品。通过试验测量，获得ACFLi30样品的热导率、孔比表面积、孔体积和孔径等参数。并对多种温湿度工况下的平衡和动态吸附性能进行测试，研究了不同温湿度条件下样品的吸附特性。结果表明样品的吸水量可达1.1 g/g（20℃、75% RH）。利用同步热分析仪测试了复合吸附剂的储热密度，ACFLi30的质量和体积储热密度分别达到1.08 kW·h/kg和588.2 kW·h/m³。与膨胀蛭石和活性氧化铝等基质相比，活性碳纤维毡基质在体积储热密度更具优势。

关键词: 活性碳纤维毡, 吸附剂, 氯化锂, 吸附, 解吸, 储热