Design of Integrated Heat Exchanger into Solar Absorber for Affordable Small-scale Concentrated Solar Power Generation (SCU)

Abstract

A solar absorber for a concentrated solar power (CSP) dish system includes a cylindrically shaped blackbody cavity receiver fused to a cylindrically shaped heat exchanger shell covering the receiver to form a monolithic cavity receiver and heat exchanger. An exterior surface of the cavity receiver has grooves embedded to create a duct spiraling about the exterior of the cavity receiver so that the duct forms tubes of a tube-style heat exchanger when covered by the heat exchanger shell. An interior diameter of the cavity receiver is greater than or equal to a diameter of an aperture of the cavity receiver, and a longitudinal interior depth of the cavity is greater than or equal to twice the interior diameter of the cavity receiver. The monolithic solar absorber is preferably composed of a ceramic material such as silicon carbide having emissivity greater than 0.9.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority from U.S. Provisional Patent Application 61 / 607,747 filed Mar. 7, 2012, which is incorporated herein by reference.STATEMENT OF GOVERNMENT SPONSORED SUPPORT[0002]This invention was made with Government support under contract SU-83603201 awarded by U.S. Environmental Protection Agency. The Government has certain rights in this invention.FIELD OF THE INVENTION[0003]The present invention relates generally to solar energy devices. More particularly, the invention relates to solar absorbers for concentrated solar power (CSP) dish systems.BACKGROUND OF THE INVENTION[0004]Concentrated Solar Power (CSP) technology seeks to replace fossil fuels in mechanical compression cycles for power generation. Existing dish systems require large areas to achieve sufficient conversion efficiency for the cost of the system. In addition, the conversion efficiencies which have been achieved are limited by the materials and manufact...

AI Technical Summary

Benefits of technology

The invention is a solar absorber for a concentrated solar power (CSP) dish system. It includes a cylindrical blackbody cavity receiver and a cylindrical heat exchanger shell. The cavity receiver has grooves embedded on its exterior surface to create tubes of a tube-style heat exchanger. The interior diameter of the cavity receiver is greater than or equal to the diameter of its aperture, and its longitudinal interior depth is greater than or equal to twice its interior diameter. The cavity receiver and heat exchanger shell are fused to form a monolithic cavity receiver and heat exchanger. The first monolithic ceramic material is silicon carbide or silicon nitride, and the interior diameter of the cavity receiver is equal to the diameter of its aperture. The duct has a rectangular cross-section. The technical effect of this invention is to improve the efficiency of solar energy conversion in CSP dish systems.

Problems solved by technology

Existing dish systems require large areas to achieve sufficient conversion efficiency for the cost of the system.

In addition, the conversion efficiencies which have been achieved are limited by the materials and manufacturing processes used.

Moreover, a solar absorber for small scale CSP has not been economically viable due to high cost for small systems.

The current technologies in the art use metal components in one form or another, which limits the overall performance that can be achieved.

Common high temperature metals will begin to fail around 1300 K and these metals have a low thermal conductivity.

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