Numerical study of an energy storage unit based on zeolite-water adsorption for mobilized thermal energy storage

Abstract

Mobile energy storage heating trucks present a promising solution to address current challenges associated with low energy utilization and reliance on a singular heat supply method. This technology seamlessly integrates waste heat recovery and thermal energy utilization, offering potential advantages such as streamlining construction cycles and providing timely energy supply in scenarios with diverse energy demands. To enhance the energy delivery efficiency of mobile heating, this paper employs computational fluid dynamics (CFD) simulation to thoroughly examine the heat accumulator at the core of an adsorption-based mobilized thermal energy storage. Furthermore, the paper conducts simulations and analyses of heat and mass transfer within a zeolite-water accumulator, closely scrutinizing variations in temperature, vapor content, and water content within the zeolite field. The results indicate that, during the heat storage process in the 3 m/s to 5 m/s system, the zeolite sensible heat storage capacity increases by 6.48 %, accompanied by a reduction in latent heat. Specifically, when the inlet steam velocity is 5 m/s compared to 3 m/s, the equilibrium heat transfer time shortens by 24.6 %. Furthermore, for an inlet steam temperature ranging from 180 °C to 220 °C, the average temperature can be elevated by 28.8 °C, resulting in a 10.6 % increase in sensible heat storage capacity. However, the heat storage time experiences a 3.4 % increase. In the exothermic process, with an inlet air velocity of 5 m/s compared to 3 m/s, there is a 22.2 % reduction in latent heat exothermic and a 16.7 % reduction in exothermic time. The inlet air temperature during the exothermic process is 8.9 °C lower than the final temperature of 20 °C, leading to a 3.2 % increase in exothermic quantity and a 20 % improvement in exothermic efficiency.