The DIAPR: A High-Pressure, High-Temperature Solar Receiver

A solar central receiver absorbs concentrated sunlight and transfers its energy to a working medium (gas, liquid or solid particles), either in a thermal or a thermochemical process. Various attractive high-performance applications require the solar receiver to supply the working fluid at high temperature (900–1500°C) and high pressure (10–35 bar). As the inner receiver temperature may be well over 1000°C, sunlight concentration at its aperture must be high (4–8 MW/m2), to minimize aperture size and reradiation losses. The Directly Irradiated Annular Pressurized Receiver (DIAPR) is a volumetric (directly irradiated), windowed cavity receiver that operates at aperture flux of up to 10 MW/m2. It is capable of supplying hot gas at a pressure of 10–30 bar and exit temperature of up to 1300°C. The three main innovative components of this receiver are: • a Porcupine absorber, made of a high-temperature ceramic (e.g., alumina); • a Frustum-Like High-Pressure (FLHIP) window, made of fused silica; • a two-stage secondary concentrator followed by the KohinOr light extractor. This paper presents the design principles of the DIAPR, its structure and main components, and examples of experimental and computational results.