Solar thermal collector cabinet and system for heat storage

Abstract

A solar thermal collection cabinet is disclosed that includes a thermal mass comprising concrete mix and metallic pieces. The cabinet includes a corrugated metallic surface with a black finish that faces solar radiation. A plurality of metallic bolts attaches the black corrugated surface to the thermal mass, to enable good heat conduction to the thermal mass. Channels through the thermal mass enable heat transfer fluid to circulate through the thermal mass, the heat transfer fluid exchange heat for direct utilization, or to transfer heat to a thermal storage reservoir through suitable heat exchanger means. Alternatively, the thermal storage reservoir continuously receives and returns heat exchange fluid whereby over extended periods of time the system approaches a thermal steady state.

1 . A cabinet for collecting solar radiant energy, storing the solar energy as thermal energy, and further for distributing the thermal energy to at least one heat transfer fluid, comprising a cabinet including a front and back wall members comprising a pair of vertical opposed wall members, and two side members comprising a pair of vertical opposed side wall members, the front wall member being transparent to solar thermal radiation, and a top and bottom wall member, the wall members being connected along their perimeters in a fluid impervious fashion forming a sealed box, a thermal mass embedded within the space defined by the wall members, the thermal mass covered by a corrugated black surface interposed between the transparent front wall member and the thermal mass, whereby the black corrugated surface is exposed to solar radiation that passes through the transparent front wall member, wherein the thermal mass and corrugated black surface are recessed behind the front transparent wall member, creating an empty space between the transparent front wall member and the corrugated black surface, the solar cabinet further including ports to enable fluid to enter and exit the empty space between the transparent front wall member and the corrugated black surface, for the purpose of heating the fluid by solar thermal radiation and heat transfer from the corrugated black surface and thermal mass, and where the thermal mass further includes channels for fluid transportation within the thermal mass, for the purpose of transferring heat from the thermal mass to a circulating fluid, the solar cabinet including fluid ports in fluid communication with the channels within the thermal mass. 
     
     
         2 . The solar cabinet of  claim 1  wherein the corrugated black surface is bolted to the underlying thermal mass with black metallic bolts, the black metallic bolts having a large surface area for heat conduction to the thermal mass and a large surface area for radiant solar heat exchange. 
     
     
         3 . The solar cabinet of  claim 1  wherein the thermal mass is a concrete mix with aluminum pieces uniformly distributed within the concrete mix, wherein the concrete mix is both lighter and more heat conductive than the concrete mix without the aluminum pieces. 
     
     
         4 . The solar cabinet of  claim 4  wherein the concrete mix is Portland cement. 
     
     
         5 . The solar cabinet of  claim 1  further including handle means enabling the solar cabinet to be lifted for transportation to an alternate location and rotated to maximize the exposure of the transparent window member to solar radiation. 
     
     
         6 . The solar cabinet of  claim 1  further including hinge means to open the transparent front wall member for cleaning and inspection of the solar thermal cabinet and its components. 
     
     
         7 . The solar cabinet of  claim 1  further including insulation between the back wall member, side wall members, and the thermal mass for the purpose of minimizing thermal loss through the wall members. 
     
     
         8 . The solar collector cabinet of  claim 7  wherein the insulation comprises several layers. 
     
     
         9 . The solar collector cabinet of  claim 7  wherein one insulation layer is a hollow layer defining a gas or evacuated space. 
     
     
         10 . The solar cabinet of  claim 5  wherein the handle means comprises metallic rods embedded through the vertical walls and through the thermal mass. 
     
     
         11 . The solar cabinet of  claim 1  wherein the fluid channels within the thermal mass are serpentine. 
     
     
         12 . The solar cabinet of  claim 3  wherein the aluminum pieces are crushed and compacted recycled aluminum cans. 
     
     
         13 . The solar cabinet of  claim 1  wherein the solar cabinet is in fluid communication with a thermal storage reservoir, through the fluid transfer ports, whereby radiant energy collected by the solar cabinet is transferred by a heat transfer fluid, circulated through the fluid channels in the thermal mass, to the thermal storage reservoir. 
     
     
         14 . The solar cabinet of  claim 1  wherein fluid circulated through the hollow space between the corrugated black surface and the transparent front wall member is in fluid communication with the thermal storage reservoir of  claim 13 , whereby radiant energy is transferred and stored by the thermal storage reservoir. 
     
     
         14 . A thermal mass to absorb heat by conduction, the thermal mass comprising an aggregate including a bonding agent and reinforcing metallic pieces. 
     
     
         15 . The thermal mass of  claim 14  wherein the aggregate is concrete. 
     
     
         16 . The thermal mass of  claim 15  wherein the reinforcing metallic pieces are aluminum.