Energy storage characteristics and size optimization of Ca(OH)2/CaO reactor with the embedded heating tube bundle
Xuguang Liu, Liqiang Duan, Z. Q. Zhu, Yu Kong, Libo Yang, Biao Chen
Abstract
Thermochemical energy storage performs better than traditional energy storage methods in energy density and long-term storage, and has less energy loss during long-distance storage and transportation. In this paper, the physicochemical model of Ca(OH) 2 /CaO reactor with the embedded heating tube bundle was established, and the thermal storage performance of the reactor was analyzed with the energy storage rate and reaction time. The variation characteristics of vapor partial pressure, temperature and calcium hydroxide concentration at the observation points were studied, and the reaction characteristics of Ca(OH) 2 /CaO reactor were revealed. The influence of reactant voidage on heat storage performance was analyzed and it was found that increasing the voidage within a certain range did not always improve the thermal storage performance, and the maximum energy storage rate was about 0.68 kW when the voidage was 0.65. In addition, the influence of the radius of heating tubes on the thermal storage performance of the reactor was studied firstly, and it was found that properly increasing the radius of heating tubes could promote the thermal storage performance, and when the radius of the heating tube was 14 mm, the energy storage rate was about 0.70 kW. Finally, the comprehensive influences of multi-dimensional size with reaction time of 20000 s as restriction condition were analyzed, and the changes of energy storage rate of the reactor under different sizes were fully revealed, which would provide an important basis for the adaptability adjustment of environmental requirements in the actual application of the reactor. In this paper, the maximum energy storage rate of the reactor with a height of 300 mm, a radius of 162.46 mm and a heating tube radius of 30.92 mm was 1.04 kW.