Thermocline packed bed thermal energy storage system
Résumé
Solar energy as a promising and renewable energy source has been applied in diverse filed for human activities. Thermal energy storage (TES) is applied to overcome the intrinsic deficiency of solar energy by migrating the dispatching between the energy supply and demand. The thermocline packed-bed TES system acted as dual-media is alternative to conventional two-tank system, exhibiting excellent cost and heat capacity advantages. It has been widely used, not only for high-temperature applications such as for the concentrated solar power, but also for industrial waste heat recovery at medium-temperature and for low temperature applications in built-environment.This book chapter provides an overview of thermocline packed-bed TES systems, covering the storage mechanisms, packing configurations, and the application temperature ranges. The influencing factors, that is, operational, geometrical, and thermophysical parameters, on the thermal performance of storage system are also surveyed. Some numerical simulation models are presented based on dimensional numbers, phase numbers, ignoring/nonignoring temperature gradient inside particles, etc. In all, the thermocline packed-bed tank with latent-sensible fillers is prospective to be promoted in future industries due to the advantages of low cost, stable performance, and high energy density. The existing challenges are also identified, including the thermocline stability, the packing topology, and the control strategy under variable operational parameters.