Windows are being evaluated for use in some high temperature solar receivers to reduce radiative and convective losses. The design process of a 1.7 meter diameter quartz dome window is explained to arrive at a window geometry able to maintain acceptable stresses when exposed to pressure differentials. The dome must be able to withstand the operational differential pressures of 0.5 MPa where the efficiency of the solar receiver/power cycle is maximized, and maximum temperatures upwards to 800°C may be observed. Brittle materials like glass need the tensile stresses to be reduced or eliminated to maximize the reliability of the dome window. However, glass does not possess a consistent characteristic strength and it is dependent on the flaw size. The dome mount is critical to maintaining an environmental seal, but careful attention must be taken in the glass-metal interface to minimize tensile bending stresses that can cause a catastrophic or rapid failure.

A method to characterize the strength of the quartz dome is discussed and aides in determining the maximum design stresses allowable during operation of the solar receiver. To determine an accurate model of the dome stress, a statistical analysis based on strength data has been carried out using the Weibull failure probability method. Finite Element Analysis (FEA) analysis of the dome is discussed, and a design trade study of the dome window geometry (ranging from a shallow angle to a full hemisphere) is presented. The combination of these perspectives will give insight on the process to design a glass dome window for this challenging environment and to predict the reliability.

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