Window design for a Small Particle Solar Receiver

Abstract

Central receivers for solar power towers have recently been under intense investigation. They can convert solar radiation into electricity by supplying heat to a standard thermodynamic cycle, commonly the Rankine (steam) cycle for commercial operation. Air-cooled solar central receivers, however, can power gas turbine engines for electrical generation in future applications. A new type of receiver module under consideration consists of an insulated pressure vessel, closed by a single or multiple large quartz glass windows and a small particle/air suspension as a working medium. A critical part of the whole assembly is the window which transmits concentrated solar flux into the receiver. The objective of our study is to analyze which windows, and procedures support safe and efficient operation of future plants with this technology. The main focus of this project is to analyze different materials obtainable from the market, and optimize the window design of one large window to cover the aperture and also for the receiver with multiple windows. A part of this work is carried out by using Finite Element Analysis of quartz glass windows of different shapes using the commercial software Hypermesh and Solidworks. The analysis will be performed taking in to account the load and boundary conditions for the window design. The operating conditions for the receiver will provide a uniform 5 bar pressure distribution on the window. The high pressure makes receiver and window design difficult. In addition to the window design, an appropriate manufacturing procedure for the window has been suggested. This paper presents the design of the quartz window for a prototype small particle receiver. Nomenclature Ts = solar transmittance at normal incidence Iλ