Direct Absorption Volumetric Molten Salt Receiver With Integral Storage

Abstract

A new design is presented for a concentrating solar power central receiver system with integrated thermal storage. Concentrated sunlight penetrates and is absorbed within a passive molten salt pool, also acting as a single-tank assisted thermocline storage system. The receiver has a relatively small aperture, open to the environment without requiring a transparent window to isolate the system, exhibiting low losses while achieving high temperatures needed for efficient power generation. The use of an insulated divider plate provides a physical and thermal barrier to separate the hot and cold salt layers within the receiver. The position of the divider plate is controlled throughout the day to enhance the natural thermocline which forms within the salt. As a result, continuous, high temperature heat extraction is possible even as the average temperature of the salt is declining. Experimental results are presented for an optically heated 5 L capacity sodium-potassium nitrate salt volumetric receiver equipped with a movable divider plate. Topics: Absorption, Storage