Particle Handling in Particle-Based Pumped Thermal Energy Storage

Abstract A novel pumped thermal electricity storage system utilizes low-cost solid particles as storage media that can deliver high-temperature heat and generate power by a high-efficiency power cycle. A counterflow direct contact gas/particle fluidized bed heat exchanger is a key component in the storage system, facilitating efficient heat transfer between high-temperature media and working fluids. A comprehensive hydrodynamic analysis of the particle fluidized bed within the heat exchanger has been conducted, optimizing key parameters such as pressure drops, air superficial velocities, minimum fluidization velocities, and fluidization regimes. To ensure optimal fluidization conditions, an air distributor has been designed and fabricated. Particle handling mechanical systems that efficiently deliver particles at high temperatures are essential in the thermal storage system. Components such as L-valve, screw conveyor, and pneumatic conveyer were designed, fabricated, and tested for a prototype laboratory-scale fluidized bed heat exchanger system.