Particles-based thermal energy storage systems for concentrated solar power

In this paper, particles-based thermal energy storage (TES) system for concentrated solar power (CSP) is presented and applied to different CSP plant-layout scenarios. The key-component of this system is the fluidized-bed heat exchanger (DPS-HX) that is used for coupling particles-based storage system to the solar loop and to the power block. Mathematical model is used for the design and thermal performance analysis of the heat exchanger coupled to subcritical and supercritical Rankine steam cycles for small and commercial plant sizes. Among the benefits of particles-based thermal energy storage it can be pointed out no temperature restrictions with no freezing nor temperature degradation, ease of handling and no toxicity. It has been found that particles heat exchanger operates at high efficiency (from 91% to 99% for most of cases) and that power consumption for fluidization purposes are negligible compared to thermal power transferred to the work transfer fluid. For large power plant size, it is preferred distributing particles among different heat exchangers connected in parallel instead of passing whole particles and work transfer fluid through just one heat exchanger component.