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Stegall, Nathan

Publications and source records attributed to Stegall, Nathan.

Salt Tank Testbed: a Test Site Designed to Replicate Floor Buckles Observed in Commercial TES Tanks

A test site has been designed and is under construction to replicate the buckling failure ob-served in several in-service storage tanks for nitrate salts operating up to 565°C. In commercial tanks multiple factors have been identified that influence the floors susceptibility to buck-ling, including: the as-manufactured shape of the floor, high compressive stresses due to thermal gradients and/or friction, fluid inventory and absolute temperature. Based on exten-sive modeling analysis it was determined that similar buckles can be reproduced in a scaled test tank (approximately 9x smaller than a representative commercial tank design). To buckle the scaled tank a radial thermal gradient is generated in the tank with a low fluid level, the fluid level is then increased while maintaining the thermal gradient; based on the modeling results just one of these cycles can plastically deform the tank floor. The test site which is under construction is designed to replicate this damaging cycle at lower temperatures. The goal of testing will be to reproduce this damaging cycle and buckle the scaled test tank floor, allowing proper model validation and a methodology for comparing different tank designs at a smaller (and less costly) scale.

25 ENERGY STORAGE↗

Structural frame and solar collector module

Solar collector modules and techniques for their construction are disclosed. In one aspect, a solar collector module includes a reflector and a three-dimensional structural frame that supports the reflector. The structural frame includes a set of primary structural shapes and a set of axial frame members connected between corners of the primary structural shapes forming helical paths for the transmission of torque from one end of the structural frame to the other. In another aspect, a method for assembling a solar collector module includes pre-assembling part of the module.

Eisinger, Joseph↗