Prefabricated insulated thermal energy storage enclosure

Abstract

A thermally insulated enclosure manufactured in pre-assembled or kit form, and constructed of prefabricated insulated sandwich panels, or structural insulated sandwich panels in some embodiments, rated for relatively high operating temperatures and designed for the storage of thermal energy in solid phase particulate storage medium or media at up to 125 deg C. and possibly higher. Said energy storage medium or media will typically be sand, gravel, or other powder or granulated material, or combination thereof, and optionally some proportion of phase change material. Said insulated enclosure is designed to accommodate a variety of heat transfer device designs in storing solar energy and off-peak-generated electric energy. The primary applications for the invention are expected to be in domestic hot water heating, space heating, and process heating, however in addition the thermal energy retained in the enclosure can also be used in powering the refrigeration cycle in some space cooling systems.

1 . A prefabricated enclosure for storing thermal energy from an external energy source of solar radiation or electricity, or a combination of the two, with said storage to be in a particulate solid phase thermal energy storage medium or media (PTESM) ( 18 ,  19 ), with said enclosure comprising prefabricated insulated panel assemblies for the floor, walls and roof, with said assemblies fabricated as structural insulated sandwich panels with rigid facings ( 1 ,  3 ) and insulative core ( 2 ), with said facings and core being layers of said panel assemblies and bonded together at their contact surfaces and designed to act compositely in resisting the gravity and lateral loading imposed by the aforementioned PTESM over its anticipated operating temperature range, or alternately with said insulative core being a foamed-in-place grade of insulation such as is possible with polyurethane foam and such that said foam self-adheres to said facings with the required adhesive strength, and with the four edges of said panel assemblies prepared in a manner to minimize thermal bridging through such edge connections ( 11 ,  12 ,  11   a    12   a ), and with panel corner edge brackets and attendant fasteners ( 8 ,  9 ) being of the necessary structural strength to connect said insulated sandwich panels to each other in a manner that maintains the structural integrity of said enclosure under all anticipated loadings, and with said enclosure suitable for the installation in its interior of one or more thermal energy input transfer device(s) to transfer thermal energy from said external source to said PTESM and one or more thermal energy output transfer device(s) being in the form of coil(s) of piping design ( 14 ), with or without heat transfer fins to transfer thermal energy from said PTESM either directly or indirectly to the “end use” application of said stored energy, with said end use being for one or a combination of domestic hot water heating, space heating, swimming pool or similar use heating, or in powering the refrigeration cycle by means of thermally-driven coolers in space cooling systems. 
     
     
         2 . A prefabricated enclosure for storing thermal energy as in  claim 1  with said insulative core of said sandwich panels to consist of multiple bonded layers of different insulative materials such that adequate structural and thermal performance is provided by the core in achieving the required structural performance of said sandwich panels as a whole thereby permitting less costly materials to be used where maximum temperature resistance requirements through the thickness of said insulative core is reduced as a result of the temperature gradient that naturally occurs through said sandwich panel assemblies with increasing distance from the aforementioned and heated said PTESM 
     
     
         3 . A prefabricated enclosure for storing thermal energy as in  claim 1 , with solar radiation being the sole aforementioned external energy source and with the aforementioned thermal energy transfer devices provided with the enclosure, and the thermal energy input transfer device(s) being in the form of coil(s) of piping design ( 14 ), with or without heat transfer fins, and with input piping to said device(s) being suitable for attachment to the outlet piping from external solar collectors that form part of the energy collection system of said solar energy source. 
     
     
         4 . A prefabricated enclosure for storing thermal energy as in  claim 1 , with electrical energy being the sole aforementioned external energy source and with the aforementioned thermal energy transfer devices provided with the enclosure, and the thermal energy input transfer device(s) being in the form of electrical resistance wiring. 
     
     
         5 . A prefabricated enclosure for storing thermal energy as in  claim 1 , with solar radiation and electrical energy being the aforementioned external energy sources with the aforementioned thermal energy transfer devices provided with the enclosure, and the thermal energy input transfer device(s) being in the form of coil(s) of piping design ( 14 ), with or without heat transfer fins and also in the form of electrical resistance wiring, such that the aforementioned PTESM can be heated by a combination of external energy sources of solar radiation and electrical energy. 
     
     
         6 . A prefabricated enclosure for storing thermal energy as in  claim 1 , and with the aforementioned thermal energy transfer devices provided with the enclosure, and the thermal energy input transfer device(s) being in the form of hot air ducting. 
     
     
         7 . A prefabricated enclosure for storing thermal energy as in  claim 2  with the aforementioned prefabricated structural sandwich panel assemblies all provided with insulative sleeves ( 16 ) at the locations where the aforementioned piping, wiring, and ducting of the associated aforementioned thermal energy transfer device(s) penetrate said sandwich panels. 
     
     
         8 . A thermal energy storage enclosure as in  claim 1  with the aforementioned prefabricated structural sandwich panel assemblies, panel assembly corner edge brackets, and fasteners, and some or all of the aforementioned internal heat transfer devices with aforementioned associated insulative sleeves all provided in kit form ready for assembly. 
     
     
         9 . A thermal energy storage enclosure as in  claim 1 , but where the aforementioned sandwich wall panel assemblies are not required to act compositely in resisting flexural or shearing stresses resulting from the lateral loading imposed by the aforementioned PTESM over the anticipated temperature range of said PTESM, but rather are braced against external framing ( 13   a ) that provides those strength requirements. 
     
     
         10 . A thermal energy storage enclosure as in  claim 1 , but where the aforementioned sandwich floor panels are not required to act compositely in resisting applied flexural or shearing stresses resulting from the gravity loading imposed by the aforementioned PTESM over the anticipated temperature range of said storage medium but rather are braced against external framing ( 26 ) or other structural floor construction as in a structural concrete slab that provides those strength requirements. 
     
     
         11 . A thermal energy storage enclosure as in  claim 1 , with the aforementioned PTESM being sand or other relatively fine particulate-sized granular matter with the option of achieving increased energy storage capacity provided by some fraction of the volume of said PTESM being displaced by a phase change material. 
     
     
         12 . A thermal energy storage enclosure as in  claim 1 , with the aforementioned PTESM being gravel or other graded and relatively coarser particulate-sized material with the option of achieving increased energy storage capacity provided by some fraction of the volume of said PTESM being displaced by a phase change material. 
     
     
         13 . A thermal energy storage enclosure as in  claim 1 , with the aforementioned PTESM being both sand and gravel or aforementioned alternatives with the two grades of said PTESM being separated from each other by one or more metallic cylindrical fabrication(s) extending between the interior facings of the aforementioned floor and roof sandwich panels of said enclosure with the main heat transfer portions in coil form of the aforementioned heat transfer devices installed inside said cylindrical fabrication(s) and said sand grade or said alternative of said PTESM being placed inside said cylindrical fabrication(s) thereby reducing the possibility of damage to said main portions of heat transfer devices during the filling process of said PTESM, and said gravel grade or said alternative of said PTESM being placed outside said cylindrical fabrication(s) with said separation of grades of PTESM thereby allowing the selective removal of said sand grade or said alternative of said PTESM thereby facilitating access to and possible removal of any said heat transfer devices installed within said fabrication(s) for service and/or replacement and said separation of grades of PTESM also yielding benefits from improved thermal energy storage characteristics of said gravel grade or said alternative of PTESM relative to said sand grade or said alternative of PTESM yet also yielding the benefits of selected use of the sand grade or said alternative PTESM as heretofore described. 
     
     
         14 . A thermal energy storage enclosure as in  claim 13  with some fraction of one or both of the aforementioned grades of PTESM being displaced by a phase change material as a means of achieving increased thermal energy storage capacity. 
     
     
         15 . A thermal energy storage enclosure as in  claim 1  in which provisions are made in the structural design of said enclosure to allow the temporary removal of specific aforementioned prefabricated sandwich roof panel assembly(ies) while maintaining the structural integrity of the overall enclosure structure either through the addition of temporary structural reinforcing elements or the installation of permanent reinforcing elements to adjacent panel assemblies, or a combination of these two methods, with said provisions being made to facilitate the selective removal by means of vacuum or other process the portion of the aforementioned PTESM residing within the aforementioned metallic cylindrical fabrication(s) and encasing the aforementioned heat transfer devices, thereby facilitating access to and possible removal of said heat transfer devices installed within said cylindrical fabrication(s) for service and/or replacement of said heat transfer devices without necessitating the removal of the remainder of said PTESM. 
     
     
         16 . A thermal energy storage enclosure as in  claim 1  with a network of prefabricated conduit to accommodate wiring and temperature sensor devices, with said conduit propitiously positioned within the interior space of said enclosure or provided in kit form for installation during the assembly process of said enclosure, thereby allowing said sensor devices to be securely installed at predetermined locations in the aforementioned PTESM for the purpose of providing data to a process control system that manages the heat transfer processes involved. 
     
     
         17 . Thermal energy storage enclosure as in  claim 1  wherein additional sandwich panel layered components, comprising a high temperature insulative layer ( 5 ) and high temperature protective liner panel ( 6 ), with the latter being in intimate contact with the aforementioned PTESM, are bonded to the aforementioned prefabricated insulated sandwich panel assemblies of the walls, floor and roof of said enclosure to provide added protection against deterioration in the structural and/or thermal performance of said sandwich panel assemblies and hence similar deterioration in the structural and/or thermal performance of said enclosure as a whole assembly, due to upper temperature extremes reached in the aforementioned PTESM that would otherwise cause a reduction in the strength and/or insulative properties of the structural layers and adhesive comprising said insulated sandwich panel assemblies. 
     
     
         18 . Thermal energy storage enclosure as in  claim 1  whereby said enclosure is installed in an exterior setting and wherein the design and specifications, or actual materials for roof framing ( 22 ) and weatherproofing components for the roof and for the walls of said enclosure are provided, with said weatherproofing components comprising conventional roof and wall sheathing ( 22 ,  23 ) and conventional roof coverings, resulting in a conventional “outbuilding” appearance, but with said energy storage enclosure forming the underlying structural form in resisting the additional imposed design loadings of an environmental nature, including wind, snow and seismic loading, and with additional aesthetic requirements met by tailoring the shape of the visible said outbuilding structure, and incorporating trim elements, including facade-style window ( 24 ) and door ( 25 ) elements in providing an appearance that is complementary to the site and adjoining buildings. 
     
     
         19 . Thermal energy storage enclosure in an exterior setting as in  claim 18  wherein the aforementioned sandwich wall panel assemblies of said enclosure are not required to act compositely in resisting applied compression forces in the axis of the facing panels, or flexural or shearing stresses resulting from the lateral loading imposed by both the aforementioned PTESM over the anticipated temperature range of said PTESM and from aforementioned design loadings of an environmental nature, but rather whereby said sandwich wall panel assemblies are braced against external framing ( 13   a ) that provides those strength requirements, with said external framing also serving as the base structural form for attachment of aforementioned wall sheathing and roof framing as required for the aforementioned outbuilding construction. 
     
     
         20 . Thermal energy storage enclosure in an exterior setting as in  claim 18  wherein the external energy source is solar, and the roof of the aforementioned enclosure outbuilding is used as a base structural form for mounting associated solar collectors ( 27 ), and furthermore, as a means of increasing space for said collectors, the roof structure in said outbuilding can be made asymmetrical to preferentially increase space available to said solar collectors.