Dynamic modeling and response characteristics of a solar-driven polygeneration system coupled with hydrogen and thermal energy storage

Abstract

In this paper, a solar-driven polygeneration system integrated with a solid oxide fuel cell, an absorption chiller, hydrogen storage, and thermal energy storage is proposed for maximally utilizing solar energy and addressing the supply–demand mismatch issue on the time scale. The dynamic model and energy management strategy of the proposed system are constructed, and the short- and mid-term dynamic response characteristics against step perturbations are investigated. Based on eco-office load demands during the typical summer and winter solstices, the long-term dynamic response behaviors of the system load-tracking are also studied. The results demonstrate that: the output dynamic response times are less than 1 s for the photovoltaic, 3–22 s for the proton exchange membrane electrolysis cell, and about 25 s for the solid-oxide fuel cell, all demonstrating short-term transient response characteristics in response to step perturbations of external parameters. In contrast, the dynamic response behaviors of the parabolic trough collector and the absorption chiller elapse 10 to 30 min to reach a stable value in response to the step changes, exhibiting typical mid-term dynamic response characteristics. Furthermore, the outputs of the system could fully satisfy the eco-office load demands in summer, while grid electricity is required to supply parts of power or heat for about 11 h in the morning and evening due to the low solar irradiation and short daylight duration in winter.