Abstract
Use of valley electricity for thermochemical energy storage that can be applied to building refrigeration is an important method for adjusting the natural fluctuations in the power grid and improving the energy efficiency of the system. This paper proposes an absorption thermochemical energy storage cycle of double compression coupled with two-stage generation to reduce the generation temperature and achieve a higher coefficient of performance and energy storage density. Based on the thermophysical properties of LiBr/H_2O and LiNO_3-[BMIM] NO_3/H_2O, the thermodynamic performance of this cycle under various working conditions was studied by MATLAB. The results showed that under the same working conditions, the temperature of the generator using LiNO_3-[BMIM]NO_3/H_2O was 34 K lower than that using LiBr/H_2O. The coefficient of performance of this new cycle using LiNO_3-[BMIM]NO_3/H_2O was obtained at 12.5, which was much greater than that using LiBr/H_2O at 7.9. Moreover, the former also achieved a larger energy storage density of 406 kJ/kg. The cycle using the LiNO_3-[BMIM]NO_3/H_2O working fluid not only exhibited better performance, but was also able to effectively use valley electricity and play the role of "peak cutting and valley filling".
NSTL
Elsevier