Granular flow and thermal performance of Moving Bed Heat Exchangers: Comparison of the Euler-Euler model with experimental results

Abstract

A moving bed heat exchanger (MBHX) is a promising technology option for efficient heat recovery from hot particles and can be used as steam generator for concentrating solar power plants with particle-based thermal energy storage. A moving bed heat exchanger is a tube bundle heat exchanger, in which a granular bulk flows downwards gravity driven while passing the heat exchanger tubes. In the tubes, a heat transfer fluid is heated up, e.g. evaporating water. For the solar specific device in focus, ceramic particles are considered as granular medium. The present contribution addresses the modeling and numerical calculation of such a device with the aim to quantify its thermal performance and to elaborate the determining factors on heat transfer. Furthermore, experimental results are presented and used for model validation.