Abstract:

In the all-solar thermal power generation, the thermochemical energy storage is a key step. In this paper, the choice of energy storage system is analyzed and the basic principle of ammonia-based thermochemical energy storage is introduced. Based on this principle, a mathematical model of an exothermic reactor （ammonia-synthesizing reactor） is established to obtain the curves of the exothermic reactor length versus the reaction temperature, of the reaction temperature versus the molar fraction of ammonia and of the average internal reactor wall temperature versus the exergy and heat energy outputs. Thus, the effects of the inlet gas temperature and flowrate on the ammonia-synthesizing reaction under definite design pressure and hydrogen-to-nitrogen ratio are directly reflected, and the optimized operation parameters to realize maximum exergy and heat energy outputs are determined. Simulated results indicate that the average temperature of the catalyst bed in the reactor is an optimal control parameter to realize maximum exergy and heat energy outputs, and that the exergy and heat energy outputs reach their maximum values at 850 ℃ and 650 ℃, respectively

Key words: thermochemical energy storage, solar thermal power generation, heat storage, exothermic reactor, numerical simulation