Design and validation of an air window for a molten salt solar thermal receiver

Abstract

This thesis contributes to the development of Concentrating Solar Power (CSP) receivers and focuses on the design of an efficient aperture. An air window is proposed for use as the aperture of a CSP molten salt receiver to mitigate efficiency losses due to heat and mass transfer. The current state of the art in CSP technology is outlined with emphasis on molten salt storage. An overview of the theory of air window devices is given, and a model is presented which can be used to predict the efficiency of the air window, given by the ratio of prevented heat and mass transfer to aperture power consumption. A design for an experimental test cell is presented, including a method of molten salt simulation and vapor concentration measurement. The test cell demonstrated the ability to lower the mass fraction of vapor outside the aperture by 77.8% ±6.2%. A high rate of cooling was observed in the test cell as the velocity of the air window was increased.