Solar thermal receiver with concentric tube modules

Abstract

A solar thermal receiver with concentric tube modules is disclosed. The outer two tubes (101, 102) of each module form an annular gap (104) for the inlet flow (109) of a heat transfer fluid (HTF). A third inner tube (103) allows for the outlet flow (108) of the HTF. Each of the concentric tube modules is bottom-supported so as to allow for thermal expansion. Embodiments may include a structural element (750) to mitigate oscillation of the concentric tube modules and/or a top-mounted bell-shaped cap (534).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 61 / 406,384, filed Oct. 25, 2010, which is hereby incorporated herein by reference in its entirety for all purposes.TECHNICAL FIELD[0002]Embodiments pertain to solar thermal receivers with concentric tube modules for converting concentrated sunlight into heat.BACKGROUND ART[0003]Solar-Thermal Receivers convert concentrated sunlight, e.g., as coming from a heliostat field, into heat and are cooled by a heat transfer fluid (HTF) such as molten salt, oil, or water. In the prior art one example includes, a receiver having one or more panels of parallel absorber tubes. Fluid flow through said panels may be parallel or in an alternate / serpentine fashion. This may result in an additional part count, e.g., valves, manifolds; complex drainage procedures; added costs; and a significant pressure drop within the receiver.DISCLOSURE OF INVENTION[0004]Emb...

AI Technical Summary

Benefits of technology

[0008]This design may allow for fewer tubes than previous receivers, as a relatively greater volume of HTF may be passed through the modules while maintaining adequate receiver characteristics such as a good heat transfer coefficient and low pressure drop. The reduced supports required by this receiver design may allow for thermal deflection. The reduced supports may also allow for the addition of more tube modules, and greater HTF flow, at the same weight as other solar thermal receivers. Alternatively, the reduced supports may allow for the creation of a lighter solar thermal receiver, which may also reduce tower costs. In embodiments where the tube modules and / or headers are manufactured separately, the number of tube module welds required may decrease. Additionally, the solar thermal receiver may be broken up into parts for greater shipping efficiency.

[0009]One exemplary embodiment may include drain valves located in the bottom of the receiver modules. In the exemplary bottom-supported module, the number of drain valves may be reduced compared to prior art solar thermal receivers as the design does not include a flow path that includes several up and down serpentine passes of HTF where freeze points may be created at the low point of any U-bend created. In an exemplary embodiment, the receiver modules may contain no bottom-connected U-bends.

Problems solved by technology

This may result in an additional part count, e.g., valves, manifolds; complex drainage procedures; added costs; and a significant pressure drop within the receiver.

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