Abstract:
The present invention is a self-contained, solar powered heating and cooling system for a building. The collector has an insulated heating chamber, and a light transmissive cover and a thermostatically controlled vent. The chamber contains absorptive columns standing on the floor. An internal liquid conduit exposes the liquid to the heat within the chamber. The collector is connected to a remote thermal reservoir such that a liquid circuit and a separate gas circuit both circulate heated fluid to the reservoir. Heat can be stored in any of a liquid reservoir, thermal mass reservoir and gas reservoir. Wind powered generators and photovoltaic cells provide power for the system or other applications. The thermal reservoir has heat exchangers which deliver stored heat to the building or operate a heat operated refrigeration machine (e.g., a liquid absorption chiller). Additional self sustaining power sources may optionally be incorporated into the present invention.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to collection systems for self sustaining energy sources. More particularly, the invention comprises a solar thermal collector which heats both gas and liquid in separate circuits and also provides wind and photovoltaic electrical generation. The collector is associated with a thermal reservoir for storing thermal energy. The generator can power a fan and a pump for thermal collection, and optionally augment heat stored in the reservoir with resistive elements powered by the generator. A number of additional self sustaining energy generation systems could easily be adapted to complement solar and wind sources, as well. 
     2. Description of the Prior Art 
     It is desirable to exploit solar energy for heating, ventilating, and air conditioning for economic, practical, and environmental reasons. Systems employing solar power incur neither economic nor environmental fuel costs. In some applications, other sources of power are not readily available. In such applications, a self contained heating, ventilating, and air conditioning system would be both feasible and practical for providing heating, ventilating, and air conditioning services to a building. For example, a house or other building located remotely from readily available electric utility power could be heated, cooled and supplied with electricity by a self contained system. 
     Solar energy may be collected by photovoltaic cells which convert solar energy directly into electrical power. Alternatively, energy may be collected by photothermal collectors which convert solar energy directly into heat. Electricity is quite versatile in that it can be readily converted into either heat or made to generate mechanical energy for driving diverse machines. However, at the current state of the art, efficiency of thermal collectors greatly exceeds that of photovoltaic cells. Therefore, ideally a self contained heating and cooling system is reliant upon photothermal conversion for maximal energy capture and also upon photovoltaic conversion to power ancillary functions necessary to operate fluid heat transfer systems. 
     The prior art presents many attempts made over a long period of time to harness the sun. U.S. Pat. No. 4,098,263, issued to Joseph A. Lanciault on Jul. 4, 1978; U.S. Pat. No. 4,289,117, issued to Harry L. Butcher on Sep. 15, 1981; U.S. Pat. No. 4,333,448, issued to Steven A. Johnson on Jun. 8, 1982; and U.S. Pat. No. 4,526,162, issued to Nobushige Arai on Jul. 2, 1985, describe solar heat collectors, each comprising an enclosure having a cover closing a heating chamber and a fluid conduit disposed within the chamber for recovering entrapped heat. The devices of Lanciault, Johnson and Arai lack the light intercepting structure found in the novel photothermal collector, do not heat both liquid and gas separately and simultaneously, as in the present invention, and lack the supplementary wind and photovoltaic generating capability of the present invention. 
     U.S. Pat. No. 5,275,150, issued to Herman Lai on Jan. 4, 1994, presents a photothermal solar collector which provides a reflective bottom configured to reflect light against tubes containing a liquid being heated. These surfaces and tubes are parallel to the top transparent panel of the collector, rather than being perpendicular thereto, in the manner of the present invention. Lai further does not heat both gas and liquid, as does the present invention. Additionally, the solar collector of Lai lacks supplementary wind and photovoltaic generating capabilities, as seen in the present invention. 
     U.S. Pat. No. 4,551,631, issued to Gaetano T. Trigilion on Nov. 5, 1985; U.S. Pat. No. 5,075,564, issued to John J. Hickey on Dec. 24, 1991; and U.S. Pat. No. 5,394,016, also issued to Hickey on Feb. 28, 1995, describe combined wind and photovoltaic generators. These generators, however, lack photothermal collections capabilities found in the present invention. 
     U.S. Pat. No. 4,421,943, issued to Eric M. Withjack on Dec. 20, 1983, describes a photovoltaic element mounted on a portable base. Withjack lacks photothermal collection capabilities, wind generating capabilities and thermal storage capabilities, as found in the present invention. 
     None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. 
     SUMMARY OF THE INVENTION 
     The present invention provides a highly efficient photothermal solar collector which converts light rays to heat by intercepting these rays and converting them to heat prior to escape of the energy by reflection. The collector includes separate fluid paths for heating both a liquid medium, such as water or glycol alcohol, and a gaseous medium, such as air. The novel collector has a heating chamber having insulated walls and floor, and an insulated, light transmissive cover exposed to sunlight. The chamber contains hollow, open topped, metallic cylinders disposed between the floor of the chamber and proximate the cover. These cylinders are of a dark color for intercepting light rays and absorbing the heat contained therein prior to loss by reflection. A liquid conduit is likewise disposed in the heating chamber so as to also absorb heat entrapped within the chamber. 
     The solar collector also has a wind turbine and photovoltaic panels to provide additional energy in the form of electricity. The electrical energy may be employed to operate controls and fluid motive apparatus such as a pump or fan. If not consumed in moving heated fluids or for the operations of controls, generated electrical energy may be contributed to stored heat energy through resistive elements, or may be stored in batteries. Electrical energy, in excess of the needs of the system, may be directed from the system to commercial powers mains. A backup carbon fueled electricity generator may also be automatically actuated to power needed operations energy and battery charging capability whenever utility supplied electricity is interrupted, not present, or when power generated by the photovoltaic cells and/or wind powered generator is insufficient to maintain system operation. 
     To this end, the collector is connected to a remote thermal reservoir providing liquid storage capability. Heat can thus be stored for subsequent retrieval when the supply thereof exceeds demand. Heated air from the collector can be directed to the thermal reservoir to retain heat not captured by the liquid media. A suitable heat exchange system supplies heat from the reservoir to building space in the winter. 
     In the cooling season, the solar collector contributes to cooling by supplying heat to operate a heat-based cooling system, such as a system including a liquid absorption chiller. Therefore, a relatively uncomplicated, inexpensive device of significant efficiency contributes to both heating and cooling inhabited space. 
     In addition to solar and wind energy, the system can be readily adapted to capture energy from a variety of additional self sustaining sources. 
     Accordingly, it is a principal object of the invention provide a high efficiency photothermal solar collector. 
     It is another object of the invention to proved within the heating chamber apparatus disposed to intercept light and convert the same to heat prior to loss of energy by reflection from within the chamber. 
     It is a further object of the invention to enable both heating and cooling from a single solar energy source. 
     Still another object of the invention is to provide both heat and electrical power so that the heating and cooling system can deliver and remove heat from a building without relying on external power. 
     An additional object of the invention is to heat both a liquid medium and a gaseous medium simultaneously. 
     It is again an object of the invention to provide electrical energy in both the presence and absence of daylight. 
     Yet another object of the invention is to store thermal energy when the supply exceeds the demand. 
     Still another object of the invention is to be automatically controlled by a programmer or computer responsive to remote override adjustments. 
     It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
     FIG. 1 is a diagrammatic, perspective view of the solar collector employed in the present invention. 
     FIG. 2 is an environmental, schematic system diagram of the invention as incorporated into a building heating and cooling system, with internal details of the collector shown in FIG. 1 omitted for clarity. 
     FIG. 3 is a schematic diagram of an optional electrolytic heat source incorporated as a part of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Traditionally, solar energy is collected and used almost simultaneously, with little or no storage except for domestic hot water. However, while the optimal season for collection is summer, the highest demand for energy is for heating in winter. To this point there has been no efficient method for storing solar gain for future use. 
     The present invention offers a solar collection, storage and distribution system which is operative 365 days out of the year, in the collection and/or distribution mode. The collectors are ideally situated for maximum summer time gain, with storage in a combination of liquid, gas and high density solid mass reservoirs, insulated to minimize energy loss. A properly insulated, sufficiently sized thermal reservoir is capable of storing energy during peak collection periods for release during high demand seasons. 
     FIG. 1 shows novel solar collector  10 , which is the principal component of a solar heat source for serving heating and cooling needs of a building (not shown). Collector  10  has a floor  12 , lateral walls  14  projecting upwardly from floor  12 , and a light transmissive cover  16 , defining an enclosed heating chamber  18 . Floor  12  and walls  14  have non-reflective dark, preferably black, coloring within heating chamber  18 , and are insulated against passage of heat from heating chamber  18  in any suitable manner as is known to those skilled in the art. Cover  16  preferably comprises two panes (not separately shown) of glass or a suitable transparent synthetic resin, with a zone of inert gas or vacuum disposed between the two panes, so that cover  16  is also insulated against heat loss from heating chamber  18 . A prototype of solar collector  10  has produced temperatures within heating chamber  18  of 190 degrees Fahrenheit at ambient outside temperatures below 10 degrees Fahrenheit. 
     Heat is collected within heating chamber  18  by both liquid and gaseous media (not shown). An internal conduit  20  passes through heating chamber  18 , conduit  20  is arranged to abut floor  12  and to lie in a winding or circuitous path, thereby exposing a considerable length of conduit  20  within heating chamber  18 . A liquid (not shown) circulates through internal conduit  20 , thereby gaining heat by conductive transfer from the gaseous media in heating chamber  18 . Conduit  20  has an intake end  22  and a discharge end  24  for connecting conduit  20  to a liquid heat exchange circuit (see FIG. 2) utilizing heat obtained from collector  10 . Liquid is introduced to conduit  20  from intake end  22  and is discharged to the building, after heating, through discharge end  24 . 
     Collector  10  also heats air in heating chamber  18  by circulating air through the open portion of heating chamber  18 . Heating chamber  18  contains a plurality of heat transfer cylinders  26  extending upwardly from floor  12  towards and terminating near cover  16 . Each heat transfer cylinder  26  comprises a hollow column, preferably of a metal such as, but not limited to, aluminum, having black, non-reflective interior surfaces. Each heat transfer cylinders  26  has a height and a diameter, the height typically being greater than the diameter. The black, non-reflective surfaces of heat transfer cylinders  26  efficiently intercept light and re-radiated electromagnetic energy which could otherwise escape heating chamber  18 , converting this energy into heat energy which is absorbed by the air moving through and about heat transfer cylinders  26  and heating chamber  18 . While the present invention presents heat transfer cylinders  26  having continuous walls about the perimeter proximate the bottom thereof, it would be evident to one skilled in the art that the walls of heat transfer cylinders  26  could contain apertures proximate the bottom thereof to permit increased air flow therethrough. 
     Although heat transfer cylinders  26  as shown in FIG. 1 appear only at the upper left corner of collector  10 , it should be understood that they are present along substantially the entire extent of floor  12 . Likewise, although conduit  20  is depicted as extending only partially along floor  12  for clarity in FIG. 1, conduit  20 , in actual practice, extends along the entire surface area of floor  12 , with heat transfer cylinders  26  mounted above conduit  20 . Conduit  20  and heat transfer cylinders  26  are soldered, brazed, or otherwise adhered to floor  12 . 
     A limited amount of open space therefore exists within heating chamber  18 . The two fluids, air and liquid, heated within heating chamber  18  are segregated from one another by the walls of conduit  20 . Air is introduced into heating chamber  18  by an intake duct  28  and discharged from heating chamber  18 , as will be explained later, by a discharge duct  30 . 
     Solar collector  10  may be supported on a building surface (not shown) at an angle appropriate for maximally intercepting sunlight by legs  32 . The angle will, of course, vary depending on the latitude of the installation. Alternatively, collector  10  may lie directly against a building surface or otherwise be supported on the building or other supporting frame. Solar collector  10  is protected against overheating by a heat relief valve  34 . Heat relief valve  34  comprises a bimetallic spring (not separately shown) or other suitable thermostatic device capable of detecting a predetermined temperature within heating chamber  18 , which device enables heat relief valve  34  to uncover an opening  36 , enabling air to escape from heating chamber  18  to the exterior of collector  10 . Conversely, electric resistance heating elements  51  may be used to prevent freezing of the system whenever it may be idle during winter months. 
     A spray manifold  38  having a plurality of water release openings  40  is mounted to collector  10  in a position wherein water can be discharged over cover  16  at the highest point. Manifold  38  is connected to a domestic water supply  42  so that should dirt, dust, debris, ice, snow, excess frost, or any other source of frozen water accumulate on cover  16  or photovoltaic cells  46  (to be explained later), the same can be removed or cleared from cover  16  or photovoltaic cells  46  by rinsing with domestic water. This arrangement enables collector  10  to be maintained in a condition exposed to sunlight without requiring a person to ascend the building being served to manually remove the frozen water. 
     Collector  10  also includes a generator  44  and an array of photovoltaic cells  46  mounted either upon collector  10  or nearby. Generator  44  is driven by a wind turbine  48  arranged by a suitable bearing  50  to rotate in the horizontal plane about three hundred sixty degrees. Turbine  48  has a shroud  52  adapted to direct wind advantageously across blades  54 , and vanes  56  for orienting turbine  48  to face into the wind. Conductors  58 ,  60  conduct electrical power derived from generator  44  and photovoltaic cells  46  to the electrical power sub-system where generated power may be stored or immediately utilized. 
     The entire solar heat source utilizing collector  10  is shown schematically in FIG.  2 . The heat source includes a remote thermal reservoir  62  for storing heat generated by solar collector  10 . Reservoir  62  has a liquid reservoir  64  for storing a first fluid, such as water, and a gas reservoir  66  for storing a second fluid, such as air. Gas reservoir  66  preferably surrounds liquid reservoir  64  so that heat energy generated rapidly by warming air in collector  10  can be expeditiously transferred to liquid reservoir  64 . Air contained in gas reservoir  66  surrounding liquid reservoir  64  also tends to serve as insulation reducing loss of heat from liquid reservoir  64 . Thermal mass elements  150  are situated within liquid reservoir  64 . Thermal mass elements  150 , having greater density than the liquid in which they are submerged, therefore greater thermal heat capacity, increase the retentive ability of the reservoir (i.e. the number of BTUs stored per unit volume). For example, lead has a thermal heat capacity ten (10) times greater than that of water. Liquid reservoir  64  is suitably insulated to minimize heat loss from within. Liquid heated in heating chamber  18  is circulated between conduit  20 , (FIG. 1) and liquid reservoir  64  by a liquid supply conduit  68  supplying liquid reservoir  64  from discharge end  24  of conduit  20 , and a liquid return conduit  70  connecting liquid reservoir  64  to intake end  22  of conduit  20 . A closed fluid circuit wherein liquid is heated in solar collector  10 , transported to and stored in thermal reservoir  62 , and returned to solar collector  10  for reheating is thus created by conduits  20 ,  68  and  70  and liquid reservoir  64 . A pump  72  propels liquid through the closed liquid circuit on demand. 
     Similarly, intake duct  28  and discharge duct  30  connect gas reservoir  66  to heating chamber  18  so that a second closed fluid circuit dedicated to a gaseous medium is established between collector  10  and thermal gas reservoir  62 . A fan  74  forces air through the second closed fluid circuit on demand. Thus, liquid and gas are independently passed through and heated by solar collector  10 . 
     Also within thermal reservoir  62  is a thermal mass reservoir  122 . A plurality of thermal rods  124  of a material such as, but not limited to, steel are wrapped with a heat exchanger  126  comprised of tubing of a material such as, but not limited to, copper which carry heated liquid from the closed liquid circuit including internal conduit  20  (FIG.  1 ). Valve  128  diverts fluid from liquid supply conduit  68  to liquid supply conduit  68 A prior to liquid reservoir  64 , supplying heat exchanger  126 . Liquid return conduit  70 A returns cooled liquid to liquid return conduit  70  for return to internal conduit  20 . Check valves  130  within liquid return conduits  70  and  70 A between both liquid reservoir  64  and heat exchanger  126 , respectively, and the juncture of liquid return conduits  70  and  70 A prevent fluid from backing up into the conduit not in current operation. Valve  128  may be used to fully divert flow from liquid reservoir  64  to heat exchanger  126  or partially divert flow so that both liquid reservoir  64  and heat exchanger  126  receive heated liquid simultaneously. 
     The electrical power sub-system of solar collector  10  is seen to include a storage battery  76  and a hydrocarbon powered electricity generator  78 . Battery  76  is located remotely from collector  10  and is connected to conductors  58  and  60  (FIG. 1) by conductor  80  so that power generated at or near solar collector  10  may be stored for subsequent use. Generator  78  is in standby mode and automatically actuates when utility supply electricity is interrupted. Generator  78  may also be connected to a power mains by a power cord and plug  79 , as shown, or by permanent hard wiring (not shown). Generator  78  provides alternative power supply should power generated at solar collector  10  be insufficient to meet electric usage demand of the system. DC power from battery  76  may be connected to respective motors  82 ,  84  of pump  72  and fan  74  by respective conductors  86  and  88 . Battery  76  may also be charged by hydrocarbon fueled generator  78 , as well as trickle charged by photovoltaic cells  46 , or other ancillary power sources (not shown). 
     Motors  82 ,  84  are controlled by suitable switches  90 ,  92 . Although switches  90 ,  92  and other switches employed in the novel heating and cooling system may be manual, it is preferred that system switches be automatic switches, such as relays or other electronic equipment. Relays are conveniently operated from a master controller  94 . Controller  94  may be thermostatically governed, or may, as depicted, be subject to control from a personal computer  96 , either locally by direct connection (not shown) or remotely through a modem (not shown but integral or associated with computer  96 ) and telephone line, shown symbolically at  98 . Although a purely mechanical scheme could be arranged to operate controller  94 , an automated scheme is preferred. Automated schemes, such as those utilizing computer  96  or any programmable controller, are more easily modified. Illustratively, pump  72  and fan  74  are more readily correlated to daily variable duration of sunlight during winter months by a programmable controller. Controller  94  is connected to system power by conductors  100  and to switches  90 ,  92  by control conductors  102 ,  104 . 
     Power available from wind generator  44  and photovoltaic cells  46  may exceed demand arising from controls, pump  72  and fan  74 . If such condition occurs during extreme demand for heat, then electrical energy may be converted into heat energy in liquid reservoir  64  by a resistive heating element  106  and in gas reservoir  66  by a resistive heating element  108 . It would be obvious to one skilled in the art that a resistive heating element could also be applied to thermal mass reservoir  122 , but such transfer would be much less efficient than in liquid reservoir  64  or gas reservoir  66 . Resistive elements  106 ,  108  are connected to system power through conductors  110 ,  112 . Switches  114 ,  116 , both governed by controller  94  through control conductors  118 ,  120 , control conductors  110 ,  112 . Heat energy derived from electrical power supplements that which is available as stored energy from collector  10 . Valve  128  is controlled by control conductor  132 . 
     In addition to the solar and wind driven elements discussed to this point, the system could also include could include additional self sustaining power sources. 
     Referring now to FIG. 3, electricity generated by the photovoltaic cells  46  or wind powered generator  44  may be used to power an electrolytic means for extracting combustible hydrogen and oxygen from water. Electrolysis chamber  142  could be located externally from thermal reservoir  62 . DC power supplied from storage battery  76  by positive conductor  144  and negative conductor  146 , with an appropriate DC to DC power converter for producing a suitable voltage for the electrolytic process, electrolyzes water within electrolysis chamber  142 . Oxygen is conducted by oxygen conduit  148  to oxygen storage tank  150  while hydrogen is conducted by hydrogen conduit  152  to hydrogen storage tank  154 . On demand, oxygen and hydrogen stored in their respective tank  150 ,  154  are conducted to combustion chamber  156  (preferably disposed within thermal reservoir  62 ) by oxygen conduit  148 A and hydrogen conduit  152 A. Ignition of the oxygen/hydrogen mix within combustion chamber  156  is supplied by igniter  158  supplied by conductor  160  from storage battery  76 . Condensate resulting from the combustion of the oxygen/hydrogen mix may, optionally, be collected and returned to electrolysis chamber  142  by water conduit  162 . Alternatively, hydrogen may be conducted to fuel cell  164  by hydrogen conduit  152 B for conversion to electrical energy and incidental heat. Fuel cell  164  could be located external or external of thermal reservoir  62 . It would be obvious to one skilled in the art that alternative electrolytic systems know to the art could be effectively utilized in the present invention. 
     Likewise, various devices and methods (not shown) known to the art for directly producing electrical and/or thermal energy from fissionable materials could be used to supply additional heat and/or electrical power. 
     Alternatively, if electrical energy derived from collector  10  in excess of all heating/cooling demands, excess electrical energy may be diverted by switch  134  to inverter  138  for conversion from DC to AC power and fed to the building&#39;s general electrical lines by transmission lines  140  for use in other applications. Switch  134  is controlled by control conductor  136 . 
     Thus far, the novel solar heat source has been described. Utilization of heat and electrical power derived therefrom will now be described. During the winter heating season, heat is obtained from liquid reservoir  64  by connecting suitable conduits and pump (neither shown) thereto. Heat stored in liquid reservoir  64  may be conducted to any suitable heating equipment, such as hot water baseboard heater  2 , functionally connected with the reservoir incorporating a heat exchanger within liquid reservoir  64 . The conduits may be arranged in any suitable recirculation scheme. Likewise, domestic water could be heated by passing it through copper coils running through liquid reservoir  64 . Of course, a forced air furnace  6  may be connected to liquid reservoir  64 , gas reservoir  66  or thermal mass reservoir  122 , or any combination thereof. 
     In the summer cooling season, heat derived from liquid reservoir  64 , gas reservoir  66 , or thermal mass reservoir  122 , or any combination thereof, is connected to a heat operated air conditioning machine  4 . Machine  4  may be a liquid absorption chiller and associated heat exchanger and air propulsion devices (not shown). Heater  2 , forced air furnace  6  and machine  4  may be located in close proximity to thermal reservoir  62  or remotely, in the later case being suitably connected by conduits (not shown). 
     It would be evident to one skilled in the art that collectors  10  could be mounted in gangs to increase the collection area and that a plurality of thermal reservoirs  62 , could be utilized to increase storage capacity. It would be further evident that any one thermal reservoir  62  need not contain each of a liquid reservoir  64 , a thermal mass reservoir  122 , or electrolytic combustion chamber  156 , but rather, could contain a plurality of any or all. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.