Abstract
The centrifugal particle receiver (CentRec), a direct absorbing receiver operating with ceramic particles, demonstrated at the Julich solar power tower under solar conditions technical large-scale feasibility, generating particle outlet temperatures up to 965 °C. To push particle based CSP technology further towards commercial application the high particle temperatures have to be transferred to a working fluid, like air. A gas-particle trickle flow direct contact heat exchanger (TFHX) has been identified with great potential for high efficiency heat transfer. Inspired by chemical trickle flow reactors and previous work in literature focusing on the gas-particle TFHX concept for temperatures up to 500 °C, the approach and its applicability for high temperature heat exchanger shall be developed further in future. In preparation for subsequent research activities, the present work focuses on the preliminary selection of suitable packing structures for the TFHX. Packing assessment criteria are defined and used to assess the particle behavior within a variety of 44 different packing geometries. The analysis was performed using the open source DEM software LIGGHTS-PUBLIC whereas at this early stage of investigation gas presence was neglected. In the analysis process the packing structures are assessed with the previously defined assessment criteria and reduced to one type of a favorable geometry type. In conclusion, the advantageous characteristics of the identified geometry type are discussed. The presented study gives a methodical selection for packing structures and first starting point for further investigating in the field of the gas-particle TFHX whereas in subsequent work the influence of gas flow to the particle dynamic must be investigated by experimental and simulation work.
