Analysis and Design of the Volumetric Air Heating Receiver

摘要

Pacific Northwest Laboratory (PNL) has performed a preconceptual design and cost evaluation of a volumetric receiver, a novel approach for producing high temperature air for process heat applications. In this central receiver concept, solar energy is concentrated by a field of heliostats onto the receiver which is located on top of a tower. The concentrated flux is intercepted throughout a matrix of fins or fibers rather than on the surface of the receiver, hence the reference to ''volumetric'' absorption. An exterior row of reflecting fins which act as a ''light valve'' to allow energy to enter the receiver but inhibit thermal radiation and reflection from leaving the receiver is a critical feature of the concept. Ambient air is drawn in through the absorbing array, cooling the receiver and heating the air. The air is then drawn through downcomer piping to heat-exchangers. Through the design evolution of this receiver, several qualitative advantages that made the concept attractive were lost. What had originally been envisioned to be a compact and simple air receiver design turned out to be much larger and more complicated when the preliminary engineering design was completed. A much lower efficiency was also predicted at the end of the study. Due to the complexity of the design, the lower efficiency, and a list of major technical uncertainties discussed in this report, PNL has recommended that the volumetric receiver project be discontinued. (ERA citation 10:044020)