Properties of Bulk Materials for High-Temperature Air-Sand Heat Exchangers
Abstract
Dispatchability of CSP and a further reduction of levelized electricity costs are strong incentives for the development of cost-efficient technical solutions for thermal storage systems. A heat storage system using fine-grained particles as its storage material is a technology option that offers novel low-cost solutions. The implementation of this concept however depends on a viable concept for an air-to-particle heat exchanger, a component that is needed to heat up the particle flow and that is not available on the market today. SolarInstitut Jülich (SIJ) and the German Aerospace Centre (DLR) are developing and testing a new air-to-particle heat exchanger (Warerkar et al., 2009). Relevant problems include high temperature gradients in sand and frame structure, the pressure drop through the heat exchanger, the thermodynamic behavior and the fluid dynamic interaction within the bulk material.