Stationary, solar-powered boiler for generating steam

This is a continuation of co-pending U.S. application Ser. No. 11/848,839, filed Aug. 31, 2007, the disclosure of which is incorporated herein by reference.

This invention relates to apparatus employing solar energy to power steam boilers, including steam boilers useful in generation of electricity.

This invention provides, in one embodiment, a novel and surprisingly effective solar-powered steam boiler which harnesses the power of solar energy in a unique and highly efficient way to generate steam, which can then be used for various purposes, including for example the generation of electricity. Thus, one embodiment of the invention is a boiler for generating steam, the boiler comprising a substantially enclosed housing configured to contain an amount of water to be boiled, the housing comprising one or more thermally conductive sidewalls which form a substantially enclosed water chamber and a reflection chamber, the reflection chamber including a closed top portion and a opening through which light rays may pass, the opening being vertically disposed below the top portion of the chamber so that the reflection chamber may trap heat, wherein at least one of the thermally conductive sidewalls is disposed so as to divide the water chamber from the reflection chamber; a support structure attached to or integral with the housing, which support structure supports the housing in a substantially fixed position during use of the boiler; and reflecting means for reflecting sunlight through the opening of the reflection chamber and onto a focal point on one or more inner surfaces of the top portion of the reflection chamber.

In another embodiment of the invention, the boiler further comprising a feed conduit sized and configured for controlled feeding of steam under pressure through at least one of the sidewalls and into the top portion of the reflection chamber. In a particular embodiment of the invention, the steam is superheated steam formed within the water chamber during boiler operation. The boiler may further comprise a control valve which terminates the steam feed through the feed conduit when sunlight is not being reflected into the reflection chamber.

In some boiler embodiments of the present invention, the reflecting means comprises a tracking heliostat. In still other embodiments, one or more of the thermally conductive sidewalls of the housing further define, at least in part, a release chamber through which heated gas and/or steam from the reflection chamber may flow before being released into the atmosphere, at least one of the thermally conductive sidewalls of the housing which defines the release chamber placing the release chamber in thermal communication with the water chamber so that at least a portion of the heat in the release chamber generated during boiler operation is absorbed by water when water is present in the water chamber. In another aspect of the invention, the opening of the reflection chamber may be sized and configured so that reflected sunrays from the reflecting means pass through the opening and are incident upon the focal point during daylight hours.

Another embodiment of the present invention is a method of generating steam. This method comprises providing water to a water chamber formed by a substantially stationary boiler housing; reflecting sunlight onto a focal point in a top portion of a reflection chamber, the reflection chamber being defined by at least a portion of the boiler housing and being in thermal communication with the water chamber, the reflection chamber defining the top portion and a bottom opening vertically disposed below the top portion so as to at least partially trap heat in the reflection chamber when sunlight is reflected onto the focal point to thereby transfer heat into the water chamber to generate steam therein; injecting a portion of the steam formed in the water chamber into the top portion of the reflection chamber while sunlight is reflected onto the focal point; and controllably releasing steam from the water chamber.

Still another embodiment of the invention is a method of generating electricity, the method comprising carrying out the method of generating steam as summarized above, and feeding the steam controllably released from the water chamber into a steam turbine to thereby generate electricity.

These and other embodiments and features of this invention will be still further apparent from the ensuing description, figures and appended claims.