Apparatus for collecting, intensifying and storing solar energy

Page 1scan →

United States Patent (19)

Nilsson, Sr.

54 apparatus for collecting,

Intensfying and storing solar

Energy

(75) Inventor: Jack E. Nilsson, Sr., Easley, S.C.

73) Assignee: Seige Corporation, Greenville, S.C.

Related U.S. Application Data 63 Continuation-in-part of Ser. No. 57,733, Jul. 16, 1979,

51 int.C.'................................................. F24J 3/02 52) U.S. C. .................................... 126/430; 126/435;

290,851 12/1883 Calner ................................. 126/438 1,599,481 9/1926 Marcuse ........ ... 126/438 1,661,473 3/1928 Goddard et al. . ... 126/438 1,951,403 3/1934 Goddard ........... ... 126/440 4,010,732 3/1977 Sawata et al. ... 60/641 4,043,315 8/1977 Cooper...... ... 126/440 4,056,093 11/1977 Barger ................................. 26/440

4,106,479 8/1978 Rogers ................................ 126/439

Foreign patent documents

472427 12/1950 Italy .................................... 126/438

Primary Examiner-Larry Jones

Attorney, Agent, or Firm-Dority & Flint

A method and apparatus for collecting, intensifying and storing solar energy which includes a hollow spherical vessel 10 having a polished reflective interior surface. A window 32 is provided in the wall of the vessel for allowing concentrated rays from the sun to enter into the interior of the vessel and be absorbed by a solar collector 20. The collector includes a substantially black (or a selective coating) heat absorbing surface, carried by a spherical member 16 which is centrally located within the spherical vessel. Heat absorbing media 18 such as metal shots are carried within the spherical member and change from a solid state to a liquid state as it absorbs the solar energy. The heat absorbing media 18 cause radiant energy to be radiated. radially in a symmetric beam pattern to the reflective vessel wall where the radiation is reflected back to the spherical member 16. The reflected radiant energy, in conjunction with the sun's rays, intensify the tempera ture of the heat absorbing media, producing a thermal power supply.

7 Claims, 5 Drawing Figures

Drawings

Page 2drawing sheetscan →

Page 3drawing sheetscan →

Page 4drawing sheetscan →

Page 5scan →

ment, in the form of metal shots is carried in the spheri

APPARATUS FOR COLLECTING, INTENSIFYING cal container for absorbing and storing the thermal AND STORING SOLAR ENERGY energy collected by the solar collector causing radiant energy to be emitted from the spherical container. A

This is a continuation-in-part application of copend 5 polished reflective surface is carried on the interior wall ing U.S. patent application, Ser. No. 06/057,733 entitled of the spherical vessel for reflecting the radiant energy "Method and Apparatus for Collecting, Intensifying back to the spherical container intensifying the temper and Storing Solar Energy' filed in the United States ature of the heat absorbing means.

Patent and Trademark Office on July 16, 1979, now Normally, the heat absorbing means begins in a solid U.S. Pat. No. 4,280,482. 10 state; and as the intensity of the temperature supplied by BACKGROUND OF THE INVENTION the rays from the sun and the reflected radiant energy. increases, it is changed from a solid to a liquid state. As

The present invention relates to a method and appara a result of the radiant energy being reflected back and tus for storing solar energy and, more particularly, to a forth between the exterior wall of the spherical con method and apparatus for collecting, intensifying, and 15 tainer and the interior wall of the vessel, the spherical storing solar energy for subsequent use. Heretofore, container with the heat absorbing means therein is energy as a source of power has normally been col raised to very high temperatures. Transfer tubes are lected by solar collector panels mounted on structures carried within the spherical container through which a in open space through which fluid such as air or liquid heat transferring fluid passes for removing heat from passes for transferring the collected thermal heat to a 20 the molten heat absorbing means for use as a source of storage chamber for subsequent use. These storage beds thermal power. A vacuum is provided in the space may take many different configurations, and one partic between the external wall of the spherical vessel. A ular configuration utilized are rock beds that are posi vacuum is also provided in the interior of the spherical tioned below the building. One problem with rock beds container.

is that they are not a very efficient means of storing high 25 In another embodiment, heat is removed from the temperatures. While these storage chambers heretofore molten heat absorbing means by selectively opening a utilized may be satisfactory for heating buildings and door for allowing radiant energy to pass therethrough the like, they would not be satisfactory for operating and strike a radiant exchanger.

power plants. Accordingly, it is an important object of the present In U.S. Pat. No. 4,056,093, there is disclosed a solar 30 invention to provide a method and apparatus of produc heating unit which includes a double wall boiler having ing a high intensity source of thermal power from solar a pair of spaced inner and outer hemispherical walls energy.

defining a closed chamber therebetween in which liquid Another important object of the present invention is that is to be heated is carried. Solar energy passes to provide an apparatus for collecting, intensifying, and through a lens system for heating the liquid. 35 storing solar energy which is clean and extremely sim In U.S. Pat. No. 4,043,315, there is disclosed an omni ple in operation.

directional solar heater collector having a transparent, Still another important object of the present inven spherical outer shell. A spherical inner shell is carried tion is to provide a power source which utilizes solar within the outer shell and contains a plurality of light energy in combination with reflected radiant energy to magnifying lens spaced along the periphery thereof. A produce a high intensity thermal supply. plurality of heat collecting elements is carried within These and other objects and advantages of the inven the inner shell spaced from the magnifying lens so that tion will be come apparent upon reference to the fol maximum light and heat intensity focuses upon these lowing specification, attendant claims and drawings. elements.

In U.S. Pat. Nos. 1,169,839, 1661,473, and 1,599,481, 45 BRIEF DESCRIPTION OF THE DRAWINGS there are disclosed other solar heaters and accumulators FIG. 1 is a sectional view of a solar power source in which a liquid is heated by the rays of the sun utiliz constructed in accordance with the present invention. ing lens systems and reflecting mirrors. FIG. 2 is a sectional view of a modified form of the One problem with the majority of the solar heaters invention.

heretofore utilized is that they do not generate and store 50 FIG. 3 is a schematic illustration showing a solar cell temperatures of sufficient intensity for operation of constructed in accordance with the present invention power plants and the like during periods of time of being utilized for heating hot water and/or steam for darkness or during inclement weather when clouds and residential or industrial use.

the like reduce the solar rays received by the collector. 55 FIG. 4 is a schematic illustration showing a solar cell SUMMARY OF THE INVENTION constructed in accordance with the present invention being utilized in an industrial application such as a

A method and apparatus for collecting, intensifying, major power generation plant, and and storing thermal energy which includes a hollow FIG. 5 is a sectional view of a modified form of the spherical vessel having an interior wall. A window is invention.

provided in the wall of the vessel for allowing concen DESCRIPTION OF A PREFERRED trated rays from the sun to enter into the interior of the EMBODIMENT vessel. A spherical container is centrally located within the vessel and has a solar collector carried thereon. The Referring in more detail to the drawings, there is solar collector, in one particular embodiment, is coni illustrated in FIG. 1 a solar power cell constructed in cally shaped and has a substantially black (or selective 65 accordance with the present invention which includes a coating) surface thereon for receiving and absorbing the hollow spherical vessel 10 constructed of any suitable rays passing through the window of the spherical ves material such as stainless steel that has a reflective pol sel. Heat absorbing means, in one particular embodi ished coating 12 provided on an interior wall thereof.

Page 6scan →

This coating can be any suitable highly reflective sur Any suitable optical system can be utilized for con face such as polished stainless steel or a mirror surface. centrating the rays of sun and focusing them on the Carried within the spherical vessel 10 is a solar col collective surface 20. It has been found that parabolic lector generally designated by the reference character mirrors can be positioned for concentrating the sun's 14, that will be referred to hereinafter as an emitter. The 5 rays and directing them through the iris assembly. The emitter includes a spherical member 16 that is filled purpose of the iris assembly is to regulate the amount of with heat absorbing material 18. Adjacent one side of concentrated rays that are supplied to the interior of the the spherical member 16 and extending into the interior spherical vessel.

The spherical vessel, as previously mentioned, may thereof is a conical-shaped member 20 (or other desir able geometric shape) that has a closed bottom 22 adja 10 be constructed of any suitable material such as stainless cent the large diameter end thereof. The interior wall 24 asteel; and as a result of being spherical in shape, there is high volume to surface ratio which minimizes heat of the conical-shaped member is coated with a substan losses to the outside, and it also tends to naturally focus tially black (or selective surface) heat absorbing surface reflective 24 which is provided for receiving and absorbing ther 15 for strikingpatternsthe of radiant heat to the center thereof emitter surface.

mal energy.

The rays from the sun are directed by converging beThere are many suitable surface coatings 12 that can utilized having satisfactory reflecting properties; and mirrors. 26 through an iris assembly 28 which can be in one particular embodiment, a silver coating is uti opened and closed for controlling the flow of rays lized. However, it is to be understood that other coat therethrough. A secondary mirror 30 reflects the con 20 ings such as aluminum, centrated rays of sunlight through an optical window 32 num reflective coatingsgold, copper, radium, and plati provided in the wall 10 of the spherical vessel. As the monoxide coated over the silveralso could be utilized. Silicon rays enter into the spherical vessel 10, they strike the tive surface from the severe thermalprotectwill the reflec environment en black solar collecting surface 24 carried on the interior countered within the spherical vessel 10. To minimize of the conical-shaped member which absorbs the ther 25 heat losses, the exterior of the vessel is polished or mal energy therefrom. This thermal energy is then coated producing a reflective surface.

transferred by means of conduction to the heat absorb In one particular embodiment, the coating on the ing material 18 carried within the spherical container interior of the conical member 20 is a carbon, however, 16. The heat absorbing material may be in the form of other suitable low emissivity-type material such as py metal shots which would become molten when the 30 rolytic graphite can be utilized for absorbing thermal system is operational. Material such as aluminum, cop energy. The fluid heat transfer media that flows per, brass, bronze, and other suitable metals would pro through the tubes 36 and the coil 38 may also be any vide good stability, be non-stratifying, and possess good suitable material such as Dowtherm, Therminol, liquid latent heat content characteristics. sodium, carbon dioxide, high pressure water, etc. The spherical container 16 has a low emissivity value 35 In order to increase the efficiency of storing thermal and is placed in or near the center of the interior of the energy in the solar cell, the spherical vessel 10 can be spherical vessel, and it is supported on a post 34. This concentrically located within another spherical vessel post assembly 34 has passages extending therethrough 40. The interior wall 42 of the spherical vessel 40 has a through which tubes 36 extend from outside of the reflective coating similar to the reflective coating 12 spherical vessel 10 to the interior of the spherical con provided on the interior wall of the spherical vessel 10 tainer 16 providing communication with a coil or other for reflecting the radiant energy back towards the emit transfer tube configurations 38 that are carried within ter 14 as shown by the broken lines and arrows. A vac the container. Fluid flows through the tubes 36 and the uum is also provided between the external surface of the transfer tubes 38 for transferring the stored thermal vessel 10 and the interior surface of the spherical vessel energy collected by the heat absorbing media 18 exter 45 40. Like reference numberals are used for the same and nally of the spherical vessel 10. The post 34 can be similar elements. Multiple spherical vessels may also be constructed of any suitable material that is a poor con utilized.

ductor of heat so as to minimize the loss of thermal In FIG. 4, the solar cell is illustrated as being utilized energy from the emitter outside of the spherical vessel. for heating water or generating steam in a tank for home One suitable material is marionite. 50 consumption and industrial use. The solar cell can be In operation, the rays of the sun are focused by the relatively small when being used for heating water. mirror system through the optical window 32 to the The heat transfer media is pumped through the tubes substantially black collective surface 24 of the conical 36 by means of a pump 44. As the fluid passes through member 20. The metallic heat absorbing material 18 the coils 38, it absorbs thermal energy from the molten absorbs thermal energy from the conical-shaped mem 55 metal 18 and is conveyed through tubes to a coil 46 ber 20. As it absorbs the thermal energy, it radiates provided in a steam generating tank 48. As the heat radiant energy radially outwardly therefrom, as shown transfer media is fed through the coil 46, it causes water by the broken arrows. This radiant energy is reflected 50 carried therein to boil to generate steam that is ex back by the mirror surface 12 carried on the interior of hausted out pipe 52. The heat transfer media is carried the spherical vessel. As a result of the reflected radiant 60 within a closed tubular system extending between the energy and the incoming solar energy passing through pump 44 and the tank 48. A reservoir 54 is provided for the window 32, the two sources of energy work in supplying the heat transfer media to the tubes 36. unison intensifying the temperature of the heat absorb Makeup water is supplied through tube 56 to the steam ing material 18, producing an intense source of thermal 65 generating tank 48.

energy. In order to minimize heat losses, a vacuum is application 4,wherein

In FIG. the solar cell is shown in an industrial the heat transfer media is fed provided in the space between the emitter 14 and the through interior wall of the spherical vessel 10. The interior of output ofthethetubes 36 to a steam generating tank 48. The steam generating tank is, in turn, fed di the emitter is also evacuated of air.

Page 7scan →

rectly to a steam turbine 58 which drives a generator 60 a double-acting cylinder so that when pressurized fluid for generating electrical power. Of course, it is to be is fed into the bottom thereof, it forces the piston rod 93 understood that the solar cell could be utilized in many upward causing the camming member 88c to engage the different industrial applications, and the application bottom of the doors 88a and 88b opening the doors to shown in FIGS. 3 and 4 are examples of such use. The permit radiant energy to pass therethrough. It can be entire assembly, such as illustrated in FIG. 4, can be seen that as the piston rod 93 is raised, the radiant ex located underground so as to minimize thermal losses, changer 89 is moved vertically upwardly closer to the or it can be carried within a concrete housing as illus emitter 84. . . . . . . . . .

trated in FIG. 3. Fluid such as water is pumped under pressure by Energy can be removed from the molten metal 18 in 10 means of a pump 94 through an inlet pipe 96. The fluid other forms than thermal. For example, a thermocouple is pressurized by the pump 94 to a pressure of 60 p.s.i. or thermonic generator can convert thermal energy to The fluid exits from the radiant exchanger 89 through a electrical energy for removal. pipe 98 and flows through a steam flow control valve Referring in more detail to FIG. 5 of the drawings, 100. As the fluid passes through the radiant exchanger, there is illustrated a modified form of the invention. The 15 it is heated from approximately 60' F. up to 250F. This thermal storage apparatus includes an outer housing 70 pressurized water then passes through the valve 100 and which has a spherical upper portion. An opening is flashes into steam in the pipe 102. As it flashes into provided adjacent the top of the housing through which steam, it drops to a pressure of approximately 15 p.s.i. thermal energy is directed by any suitable means such as The steam then is fed through any suitable receiver such disclosed in FIG. 1. The outer shell 70 may be con 20 as a steam drum 104 and is fed out of the top through structed of any suitable material such as carbon steel. valves 106 to any suitable device for utilizing the steam. The bottom portion of the outer shell terminates into a Any condensation collecting in the steam drum 104 is cylindrical housing 72. drained out the bottom through pipe 106 and is either Positioned and spaced from the outer shell 70 is an fed back to a water reservoir. 108 provided adjacent the intermediate shell 74 wich is also spherical in shape, 25 bottom of the structure or discharged. except adjacent the bottom thereof which terminates in The entire structure, as shown in FIG. 5, is positioned a cylindrical housing 76. at the particular latitude angle for the area where it is Positioned between the outer shell 70 and the inner located for maximizing the reception of rays from the shell 74 is diatomaceous earth 78 which has a K factor sun. In the particular embodiment illustrated, it is held of 0.05. ‘. .. . 30 in the position shown by a steel structure 110 that is An opening is provided in the upper surface of the bolted together and secured to the outer shell 70. intermediate shell in which a quartz window 80 is posi If it is desired to use a metallic phase change medium tioned for allowing the thermal rays to project there in the emitter so as to create temperatures above ap through and impinge upon a collector 82 carried within proximately 1,000 F., then instead of providing a vac a spherical emitter 84. A vacuum is provided in the 35 uum between the emitter shell 84 and the intermediate space between the emitter 84 and the intermediate shell shell 74, glass beads or aluminum foil flakes are posi 74, and it also extends into the upper portion of the tioned between the two shells to produce a temperature emitter. gradient drop to prevent damage to the reflective sur A metallic phase change medium 86 is carried within faces provided on the inner wall of the intermediate the emitter 84, and it can be any suitable material such shell 74 and the outer wall of the emitter 84. as aluminum which goes from a solid state to a liquid In operation, rays from the sun are directed in a con state as it absorbs thermal energy from the collector 82 centrated form by any suitable means through the win that floats on top thereof. The collector 82 is a fluid dow 80 so that they strike on the collector 82. As the carbon black surface. collector 82 absorbs the thermal energy, it causes the The outer surface of the emitter is a polished steel 45 metallic phase change medium to go from a solid state surface, and the inner surface of the intermediate layer to a liquid state. Since the carbon black collector 82 74 is also a polished surface. In one particular embodi floats on the metallic phase change medium 86, it con ment, mirror surfaces are provided instead of the pol tinues to cover the entire upper surface of the metallic ished reflective surfaces. phase change medium 86 as the phase change medium Positioned in the cylinder 76 below the spherical 50 expands and contracts.

emitter 84 is a means for controlling the transfer of After the phase change medium 86 has stored suffi radiant energy from the emitter generally designated by cient thermal energy, the emitter 84 begins to glow the reference character 88. similar to a radiant heater. The amount of radiant en The means 88 includes a pair of hinged doors 88a and 55 ergy removed from the emitter 84 is controlled by ma 88b which are selectively opened and closed by means nipulating the doors 88a and 88b. When the doors are of camming surfaces 88c that are, in turn, supported on open, radiant energy passes through the openings pro top of a radiant exchanger 89 that is circular in shape vided therein, heating the fluid or water flowing and rests on a support plate 92. The radiant exchanger through the radiant exchanger 89. This causes the pres 89 is hollow so that any suitable fluid can be pumped surized water to be heated. As previously mentioned, therethrough for transferring heat being absorbed the heated water then is passed through a valve 100 and thereby. The upper surface of the radiant exchanger is a flashes to steam in the pipe 102 for subsequent use as a black heat absorbing surface. Insulation 91 of any suit source of energy.

able type is carried on top of the rectangular shaped While a preferred embodiment of the invention has hinged doors 88a and 88b for preventing the transfer of been described using specific terms, such description is radiant energy from the emitter 84 when the doors are 65 for illustrative purposes only, and it is to be understood closed. The support plate 92 is, in turn, supported on a that changes and variations may be made without de piston rod 93 that extends out of a hydraulically or parting from the spirit or scope of the following claims. pneumatically operated cylinder 90. The cylinder 90 is What is claimed is:

Page 8scan →

1. An apparatus for collecting, intensifying or sustain means positioned between said radiant exchanger and ing, and storing solar energy comprising: said container for controlling the transfer of radiant a hollow vessel having an interior wall; energy from said container to said radiant ex a window provided in said wall of said vessel for changer.

allowing concentrated rays from the sun to enter 5 3. The apparatus as set forth in claim 2 further com into the interior of said vessel; prising:

a solar collector carried adjacent the center of said a housing wall being spaced from and enclosing said vessel spaced from the interior walls of said vessel, hollow vessel, and said solar collector including; thermal insulation carried between said housing wall (i) a container, O and said vessel providing an insulating layer. (ii) a substantially black fluid heat absorbing sur 4. The apparatus as set forth in claim 3 further com face positioned for being contacted by said rays prising:

passing through said window, said layer of thermal insulation being diatomaceous (iii) heat absorbing means carried in said container earth.

5. The apparatus as set forth in claim 2 further com supporting said substantially black fluid heat 15 prising:

absorbing surface for absorbing and storing ther mal energy from said heat absorbing surface and said means for controlling the transfer of radiant for heating said container causing radiant energy energy from said container to said radiant ex to be emitted from said container, and . changer including an adjustable door. (iv) said heat absorbing means being metal that 20 6. The apparatus as set forth in claim 5 further com goes from a solid state to a liquid state upon prising:

absorbing thermal energy from said substantially said adjustable door including, black heat absorbing surface, and (i) a plurality of hinged doors; and a polished reflective surface carried on an interior (ii) means for selectively opening and closing said wall of said vessel for reflecting radiant energy 25 doors.

back to said container intensifying the temperature 7. The apparatus as set forth in claim 6 further com of said heat absorbing means. prising: V 2. The apparatus as set forth in claim 1 further com means for moving said radiant exchanger closer to prising: said container asit saidis doors opened.

a radiant exchanger spaced from said container, 30