Abstract
Conventional central receiver power tower plants typically use steam or molten salts as the heat collection medium. Recently, attention has returned to using solid particulates in a particle-heating receiver (PHR). In this project we are interested in discrete structure PHR that includes structures, such as an array of wire mesh protrusions in our current design, to increase the residence time of particles falling through the receiver. The meshes should be sized to accommodate the falling particles without exposing too much mesh to concentrated radiation, which might degrade collection efficiency and expose the mesh material to high temperature thermal degradation. The experiment described in this paper was implemented to measure the appropriate exposed length of such discrete porous structures for a PHR.
Particulates are introduced to the model PHR from a perforated plate distributor. As detailed in the body of the paper, a laser and photosensor (responding in units of lux) are used at positions 546 mm and then 1111 mm downstream from the perforated plate to measure the transparency of the flow in a vertical plane across the receiver. The laser light forms a vertical sheet, and its intensity is measured by the photosensor on the opposite side of the receiver. By comparing the lux data with and without particles flowing, the transparency of the particulate curtain can be determined. Different mesh counts have been tested and compared, and plotted for comparison. This research is useful for designers to use when planning a PHR and will inform the proper length of wire meshes to use. This paper reports the results obtained so far including a standard error propagation analysis.