SOLAR RECEIVER WITH DIRECT ABSORPTION MEDIA IRRADIATION
A solar receiver having a receiver vessel with a receiver chamber, a receiver cover with a receiver window, a receiver fluid inlet, a receiver fluid outlet, and an absorption media matrix in the receiver chamber. In operation of the solar receiver, incident solar radiation is transmitted through the receiver window to the absorption media matrix. Receiver fluid is circulated through the receiver chamber and the absorption media matrix. Heat is transferred from the absorption media matrix to the receiver fluid.
This invention is in the field of devices and methods for solar energy collection and in particular in the field of devices and methods for the reception and absorption of solar radiation by an absorption media and transfer of the energy of the absorbed solar radiation to a transfer fluid.
There are many prior art devices and methods for the reception and absorption of solar radiation. These prior art devices may provide for the reception and absorption of radiation directly from the sun, or may provide for the reception and absorption of concentrated solar radiation from a solar collector, or both. The received and absorbed radiation may result in the direct generation of electric current, as for a photovoltaic system, or the absorbed solar energy may be transferred to a heat transfer fluid. These prior art devices involve varying levels of initial cost, operation and maintenance cost, operational complexity, operational reliability and efficiency.
It is an objective of the present invention to provide a solar receiver and a method for solar reception and absorption with low initial cost, low operation and maintenance cost, low operational complexity, long operational lifetime, and moderate to high efficiency.
It is a further objective of the present invention to provide a solar receiver and a method for solar reception and absorption that may be used for direct solar irradiation or may be used with concentrated solar radiation from a solar collector.
It is a further objective of the present invention to provide a solar receiver and a method for solar reception and absorption that may provide for the direct irradiation of a solar absorption media which is contained in and enveloped by a receiver fluid.
SUMMARY OF THE INVENTIONThe solar receiver of the present invention is comprised of a receiver vessel with a receiver chamber and a receiver cover with a receiver window, a chamber inlet, a chamber outlet, and an absorption media matrix in the receiver chamber. For an operation of the solar receiver, receiver fluid is circulated through the receiver chamber. The solar receiver may also incorporate chamber baffles which reduce short circuiting of the receiver fluid as it flows through the receiver chamber.
For a preferred embodiment of the solar receiver, the receiver fluid will preferably be air or other low density gas, such as nitrogen or an inert gas, as to increase the transmissivity of the incident solar radiation to the absorption media of the absorption media matrix. However, other embodiments may utilize clear, high transmissivity liquids, such as water, alcohol, molten salt, or light oils. The receiver vessel may have a receiver cover with a receiver window. The receiver cover may be attached to the receiver vessel wall by cover hinges, secured by a cover latch, and sealed against leakage of the receiver fluid from the receiver chamber by a fluid seal between the receiver chamber top and the receiver cover. This embodiment of the solar receiver works particularly well for use with a low pressure gas, such as low pressure air, for a receiver fluid.
A preferred material to be used for the absorption media of the absorption media matrix is a copper wool, a copper-aluminum alloy wool, or other metallic wool having a high thermal absorption rate and a high thermal conductivity. The thermal absorption rate of absorption media may be enhanced by a surface treatment, such as anodization that can be used for a copper-aluminum alloy. For preferred embodiments, the configuration of the absorption media matrix and the characteristics of the absorption media, such as fiber diameter and the total length of fiber per unit volume of absorption media for absorption media in the form of a wool-like fiber matrix, will be selected to provide for the penetration to matrix internal positions, and, therefore, for depth distribution in the absorption media matrix of the incident solar radiation transmitted to the receiver chamber by the receiver window, thereby providing for a more uniform distribution through the absorption media matrix of the energy absorbed from the incident solar radiation. The use of a high thermal conductivity material for the absorption media, such as copper wool, will result in the rapid redistribution of the absorbed energy, which will, in turn, aid in the transfer of the solar energy absorbed by the absorption media matrix to the receiver fluid.
The receiver fluid, which will preferably be a low density compressible fluid, such as air at a pressure only slightly above ambient air pressure, is introduced at a chamber inlet and follows a chamber fluid path through the receiver chamber with chamber baffles minimizing short circuiting of the chamber fluid path. Solar energy absorbed and distributed by the absorption media matrix, which, for preferred embodiments, may fill the receiver chamber, is transferred to the receiver fluid. The heated receiver fluid exits the receiver chamber through the chamber outlet to the discharge conduit which conveys the heated receiver fluid to equipment or devices for further heat exchange or utilization of the energy, such as driving a steam turbine, or other beneficial use of the received solar energy, which uses and applications will be known to persons skilled in the art.
For a preferred embodiment, the receiver window may be a material such as glass or plastic which has a low reflectivity for the incident solar radiation, preferably for a spectrum including high infrared, visible light, and low ultraviolet, regardless of the radiation incidence angle of the solar radiation. In the interest of maximizing the transmission of the incident solar radiation to the absorption media matrix, a course fiber matrix may be preferable for the absorption media of the absorption media matrix. Despite the preferred high thermal conductivity for the absorption media, the better the distribution of the incident solar radiation to the absorption media, the more efficient the energy transfer to the receiver fluid will be as the receiver fluid flow through the receiver chamber and the absorption media matrix occurs. As noted above, a preferred material for the absorption media is a copper wool or other metallic wool, which may have an absorption enhancing surface to darken the surface of the absorption media thereby increasing the rate of absorption and decreasing the rate of reflection of the incident solar radiation from the surface of the absorption media. The receiver window may have a reflective undercoating which will reduce the radiative loss of reflected chamber radiation and the infrared radiative loss of emitted infrared radiation.
A preferred embodiment of the solar receiver of the present invention has a receiver chamber with a horizontal rectangular cross-section and a vertical rectangular cross section. However, other configuration shapes of the receiver vessel and the receiver chamber will be obvious to persons with skill in the art in view of the disclosures made in the specification and the drawings of this application. A receiver chamber containing an absorption media matrix of absorption media and having a receiver cover with a receiver window providing for the transmission of the incident solar radiation to the receiver chamber and for the direct irradiation of the absorption media of the absorption media matrix of high thermal conductivity absorption media material, and providing for the circulation of receiver fluid through the receiver chamber and the absorption media matrix are the principal components of the preferred embodiment of the present invention. The receiver cover may provide for the cleaning, servicing, removal and replacement of the absorption media and the absorption media matrix.
Referring first to
For the preferred embodiment of the solar receiver 1 shown in
A preferred material to be used for the absorption media 21 of the absorption media matrix 11 is a copper wool, a copper-aluminum alloy wool, or other metallic wool having a high thermal absorption rate and a high thermal conductivity. The thermal absorption rate of absorption media 21 may be enhanced by a surface treatment, such as anodization that can be used for a copper-aluminum alloy. For preferred embodiments, the configuration of the absorption media matrix 11 and the characteristics of the absorption media 21, such as fiber diameter and the total length of fiber per unit volume of absorption media 21 for absorption media 21 in the form of a wool-like fiber matrix, may be selected to provide for the penetration of the incident solar radiation 19 to matrix internal positions 20 as shown also on
For the embodiment of the solar receiver shown in
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A preferred embodiment of the solar receiver 1 of the present invention, as shown in
As indicated above, the embodiment of the solar receiver 1 shown in
Alternative embodiments of the receiver vessel 3, particularly embodiments for using air or other gas for the receiver fluid 13, may provide for access to the receiver vessel to be provided by a side, end or bottom access, with a fluid seal to prevent receiver fluid 13 leakage. For such embodiments, the receiver window 6 may be incorporated in the receiver vessel top 8 and not incorporated in a receiver chamber top access 12 shown in
An alternative preferred embodiment of the solar receiver 1 of the present invention is shown in
Embodiments of the solar receiver 1 of the present invention may be used for direct solar irradiation or may be used for concentrated solar radiation from a solar collector. For embodiments used for concentrated solar radiation, attention must be directed to distributing the concentrated radiation over the receiver window 6, selection of material for the absorption media 21, selection of the receiver fluid 13, and providing for a receiver fluid circulation capacity that is compatible with the concentrated radiation intensity and daily and seasonal variations of the radiation intensity. The term “incident solar radiation” as used in this specification, including the claims, shall be defined to include both direct solar radiation and concentrated solar radiation.
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In view of the disclosures of this specification and the drawings, other embodiments and other variations and modifications of the embodiments described above will be obvious to a person skilled in the art. Therefore, the foregoing is intended to be merely illustrative of the invention and the invention is limited only by the following claims and the doctrine of equivalents.
Claims
1. A solar receiver for receiving and absorbing incident solar radiation and transferring energy received and absorbed from the incident solar radiation to a receiver fluid, the solar receiver comprising:
- a receiver vessel having a receiver chamber, a receiver fluid inlet, a receiver fluid outlet, and a receiver window; and
- an absorption media matrix positioned in the receiver chamber, the absorption media matrix being comprised of absorption media.
2. The solar receiver recited in claim 1 wherein the absorption media matrix has physical characteristics providing for penetration of a portion of the incident solar radiation transmitted by the receiver window to the receiver chamber, to positions internal to the absorption media matrix.
3. The solar receiver recited in claim 1 wherein the absorption media comprises a fiber matrix of fibers having a fiber diameter and a total length of fiber per unit volume of absorption media which provide for penetration of a portion of the incident solar radiation transmitted by the receiver window to the receiver chamber, to positions internal to the absorption media matrix.
4. The solar receiver recited in claim 1 wherein the receiver chamber is box shaped.
5. The solar receiver recited in claim 1 wherein the receiver chamber is spiral shaped.
6. The solar receiver recited in claim 1 wherein the receiver chamber is cylindrically shaped and has a curvilinear receiver window.
7. The solar receiver recited in claim 1 wherein the receiver chamber has one or more chamber baffles.
8. The solar receiver recited in claim 1 wherein the receiver chamber has one or more chamber baffles for reducing short circuiting of receiver fluid as it follows a chamber fluid path through the receiver chamber from the receiver fluid inlet to the receiver fluid outlet.
9. The solar receiver recited in claim 1 wherein the receiver window has a reflective undercoating for reducing a radiative loss of reflected chamber radiation and a radiative loss of infrared radiation emitted from the receiver chamber.
10. The solar receiver recited in claim 1 wherein the receiver vessel has a receiver door with a receiver door fluid seal.
11. The solar receiver recited in claim 1 wherein the absorption media is a metallic wool.
12. A method for receiving and absorbing incident solar radiation and transferring energy received and absorbed from the incident solar radiation to a receiver fluid, the method comprising:
- providing a solar receiver having a receiver vessel with a receiver window, a receiver chamber, a receiver fluid inlet, and a receiver fluid outlet, the receiver chamber having an absorption media matrix of absorption media;
- transmitting the receiver fluid through the receiver fluid inlet to the receiver chamber;
- irradiating the receiver window with the incident solar radiation, the receiver window transmitting a first portion of the incident solar radiation to the receiver chamber;
- transmitting a second portion of the first portion of the incident solar radiation through the receiver fluid directly to the absorption media of the absorption media matrix, the receiver fluid having a transmissivity which provides for the transmission of the second portion of the first portion of the incident solar radiation directly to the absorption media of the absorption media matrix without being absorbed by the receiver fluid;
- passing the receiver fluid through the absorption media of the absorption media matrix and transferring heat from the absorption media to the receiver fluid, producing heated receiver fluid; and
- transmitting the heated receiver fluid from the receiver chamber through the receiver fluid outlet.
13. The method recited in claim 12 wherein the absorption media provides for penetration of the second portion of the first portion the incident solar radiation to positions internal to the absorption media matrix.
14. The method recited in claim 12 wherein the absorption media is comprised of a fiber matrix of fibers having a fiber diameter and a total length of fiber per unit volume of absorption media which provide for penetration of the second portion of the first portion of the incident solar radiation to positions internal to the absorption media matrix.
15. The method recited in claim 12 wherein the receiver window has a reflective undercoating for reducing a radiative loss of reflected chamber radiation and a radiative loss of infrared radiation emitted from the receiver chamber.
16. The method recited in claim 12 wherein the receiver vessel has a receiver door with a receiver door fluid seal.
17. The method recited in claim 12 wherein the absorption media is a metallic wool.
Type: Application
Filed: Feb 5, 2014
Publication Date: Aug 6, 2015
Inventor: Neldon P. Johnson (Deseret, UT)
Application Number: 14/173,790