Patent Application
20230392876
Not applicable.
Not applicable.
The transition to inexpensive, but intermittent, wind and solar energy demands gigawatt-hours of storage that can then be delivered at the megawatt power level on demand. Because of the looming climate calamity, it will be necessary to cease the burning of fossil fuels. With growing interest in renewable energy resources such as wind and solar energy, there remains the question of how to effectively utilize the currently fossil fueled, industrial settings. Therefore, development of long duration, geographically and spatially agnostic, cost competitive energy storage technology is needed, especially if it can integrate the current infrastructure of the fossil fueled industrial settings.
In one embodiment, the present invention concerns thermal energy storage systems and methods. In particular, the present invention relates to the conversion of fossil-fuel-powered plants into zero-carbon renewable energy storage facilities.
In another embodiment, the present invention concerns an efficient thermal energy storage system wherein the system is designed to allow thermal energy to be stored within a dome-shaped thermal storage medium capturing the buoyant heat, thereby improving efficiency of the system.
In another embodiment, the present invention concerns a thermal energy storage repository with a reversible air blower, electrical heater, steam generator placed in a single heat exchanger duct wherein the heat exchanger duct is horizontally configured.
In another embodiment, the present invention concerns a thermal energy storage method for efficient operation of the thermal energy storage system.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
In the drawings, which are not necessarily drawn to scale, like numerals may describe substantially similar components throughout the several views. Like numerals having different letter suffixes may represent different instances of substantially similar components. The drawings illustrate generally, by way of example, but not by way of limitation, a detailed description of certain embodiments discussed in the present document.
Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed method, structure, or system. Further, the terms and phrases used herein are not intended to be limiting, but rather to provide an understandable description of the invention.
The thermal energy storage repository 200 may have a radial configuration. The radial configuration helps with storing energy as heat radiates outward from the center. In particular, the thermal energy storage repository may be dome-shaped, tapered or conical-shaped due to the radial configuration. The dome or conical-shaped thermal energy storage repository 200 is advantageous due to buoyant hot air rising to the top of the thermal storage medium 232 where it is immobilized by the impermeable membrane 262. The heat is retained by the thermal insulation layer 234. The thermal energy storage repository 200 may also be closed-loop and thereby improving energy efficiency.
In another example, the thermal energy storage repository 200 may also take on spherical configuration which may improve efficiency at retaining heat. The thermal storage medium 232 may be a porous particle bed wherein the porous particle bed may be comprised of granite gravel. The thermal storage medium 232 may also comprised of other material or combinations of materials resulting in a porous particle. In one example, the thermal storage medium is made of granite gravel having 5 cm diameter particles. In yet other examples, the particles may be greater than or less than 5 cm in diameter. The said particles may take on a spherical, oval, toroidal, or a combination thereof.
The thermal insulation layer 234 comprises materials suitable to provide further insulation and thereby helps to retain the buoyant hot air rising. The thermal insulation layer 234 may comprise of different material composition. In one example, the thermal insulation layer 234 has a fiberglass layer positioned on top and a fine silty sand layer positioned at the bottom. In another example, the thermal insulation layer 234 has a fiberglass layer positioned on the interior side and a fine silty sand layer positioned on the exterior side.
The toroidal return duct 236 may be positioned interior with respect to the thermal insulation layer 234. The toroidal return duct 236 may be made of concrete, firebrick, or clay. In one example, the toroidal return duct 236 comprises compositions from any two of the concrete, firebrick, or clay material. In another example, the toroidal return duct 236 comprises concrete, firebrick, and clay. It is noted that the combination of compositions that make up the toroidal return duct 236 may combine in a homogenous manner due to individual materials mixing well together. However, the toroidal return duct 236 may also comprise regions of individual compositions making up the entirety of the toroidal return duct 236. The heat exchanger duct 238 may be made of material that can withstand temperature up to 500° C. In one example, the heat exchanger duct 238 is made of stainless steel. The central core 240 may be either an open duct or a vertically-oriented column of large sized particles to allow for enhanced air flow. Central core 240 may have low permeability. In one example, central core 240 is perforated for radial air flow into the thermal storage medium 232; wherein central core 240 takes on a plate-steel structure. In another example, central core 240 may comprise of a refractory brick withstanding a maximum temperature of 800° C.
Steam generator 242 and electrical heater 243 module may be a standard pipe heater exchanger, resistance heater, microwave, or similar heater. The steam generator 242 and electrical heater 243 module may withstand a maximum temperature of 1100° C. The air blower 244 is reversible and may be made from standard equipment from the power industry. The air blower 244 may withstand temperatures of up to 500° C. The air return duct 246 may be made of stainless steel. In other examples, the air return duct 246 may also be made of standard equipment from the power industry. The pressurized steam to turbine or other industrial process 248 is transported using standard stainless-steel steam pipes with fiberglass insulation. The pipes may be able to withstand a maximum temperature of 600° C. The impermeable membrane 262 may be made of fiberglass cloth. The impermeable membrane 262 may be made of other insulating material. The member may withstand a maximum temperature of 800° C. The power supply 250 may be interchangeably referred to as the electrical supply may come from a high-voltage transmission line. In one example, the power supply 250 comes from renewable resources. The said renewable resource may further come from solar, wind, or hydro or a combination thereof.
The thermal energy storage repository 300 comprises a thermal storage medium 332, a thermal insulation layer 334, a steam generator 344, an electrical heater 340, an air blower 342, an air return duct 346, pressurized steam to turbine or other industrial process 348, a power supply 350, and an impermeable membrane 362.
Additionally, the thermal energy storage repository 300 may further comprise a toroidal return duct, a central core, and a heat exchanger duct which are not shown in
The thermal energy storage repository 300 may have a radial configuration. The radial configuration helps with storing energy has heat radiates outward from the center. In particular, the thermal energy storage repository may be dome-shaped, tapered or conical-shaped due to the said radial configuration. The dome or conical-shaped thermal energy storage repository 300 is advantageous due to buoyant hot air rising to the top of the thermal storage medium 332 where it is immobilized by the impermeable membrane 362. The heat is retained by the thermal insulation layer 334. The thermal energy storage repository 300 may also be closed-loop and thereby improving energy efficiency.
In another example, the thermal energy storage repository 300 may also take on spherical configuration which theoretically may improve efficiency at retaining heat.
The thermal storage medium 332 may be a porous particle bed wherein the porous particle bed may comprise of granite gravel. The thermal storage medium 332 may also comprise other material or combination of materials resulting in particle bed being porous. In one example, the thermal storage medium is made of granite gravel having 5 cm diameter particles. In yet other examples, the particles may be greater than or less than 5 cm in diameter. The particles may take on a spherical, oval, toroidal, or a combination thereof.
The thermal insulation layer 334 comprises materials suitable to provide further insulation and thereby helps to retain the buoyant hot air rising. The thermal insulation layer 334 may comprise of different material composition. In one example, the thermal insulation layer 334 has a fiberglass layer positioned on top and a fine silty sand layer positioned at the bottom. In another example, the thermal insulation layer 334 has a fiberglass layer positioned on the interior side and a fine silty sand layer positioned on the exterior side.
The toroidal return duct may be positioned interior with respect to the thermal insulation layer 304. The toroidal return duct may be made of concrete, firebrick, or clay. In one example, the toroidal return duct comprises compositions from any two of the concrete, firebrick, or clay material. In another example, the toroidal return duct comprises concrete, firebrick, and clay. It is noted that the combination of compositions that make up the toroidal return duct may combine in a homogenous manner due to individual materials mixing well together. However, the toroidal return duct may also comprise regions of individual compositions making up the entirety of the toroidal return duct. The heat exchanger duct may be made of material that can withstand temperature up to 500° C. In one example, the heat exchanger duct is made of stainless steel. The central core may be either an open duct or a vertically-oriented column of large sized particles to allow for enhanced air flow. The central core may have low permeability. In one example, the central core is perforated for radial air flow into the thermal storage medium 332; wherein the central core takes on a plate-steel structure. In another example, the central core may comprise of a refractory brick withstanding a maximum temperature of 800° C.
The steam generator 344 and electrical heater 340 module comprises a standard pipe heater exchanger, resistance heater, microwave, or similar heater. The steam generator 344 and electrical heater 340 module may withstand a maximum temperature of 1100° C. The air blower 312 is reversible and may be made from standard equipment from the power industry. The air blower 342 may withstand temperatures of up to 500° C. The air return duct 302 may be made of stainless steel. In other examples, the air return duct may also be made of standard equipment from the power industry. The pressurized steam to turbine or other industrial process is transported using standard stainless-steel steam pipes with fiberglass insulation. The pipes may be able to withstand a maximum temperature of 600° C. The impermeable membrane 362 may be made of fiberglass cloth. The impermeable membrane 362 may be made of other insulating material. The member may withstand a maximum temperature of 800° C. The power supply 350 may be interchangeably referred to as the electrical supply may come from a high-voltage transmission line. In one example, the power supply 350 comes from renewable resources. The said renewable resource may further come from solar, wind, or hydro or a combination thereof.
The angled nature of cap 401 reduces the settling of thermal storage medium 402, which may be gravel or other material as described above. Settling is an issue since, as the packed bed expands and shrinks under thermal cycling, it may settle, thus reducing the air voids in the packed bed. Permeable screens 414-416 may be included to prevent gravel from moving from and within the repository 400.
Also provided is a heat exchanger 406 connected to blower 409 by duct 408. In a preferred embodiment, heat exchanger 406 is embedded within the thermal repository 400. Top 401 and heat exchanger 406 include an insulation barrier 403. An insulated bottom 410 may also be used. Insulation 403 and 410 may be made as described above.
Duct 407, which may be toroidal, is also in communication with air blower 409 and medium 402 through vents 404 and 405. Thus, in operation, heat is added to the repository by employing blower 409 to conduct air via duct 408 into heat exchanger 406 and then into the thermal storage medium 402. Heat is extracted by reversing the direction of flow of blower 409.
It is noted that charging of the thermal energy system 100 may refer to powering electrical heater which will heat air blown by the air blower 244 or 312. In step 510, if it is determined that the available renewable energy source has reached a predetermined threshold, the renewable energy source is used to power the electrical heater. In the energy charging step 512, air is heated in the center of the repository 200 or 300 as in step 514. Heating is expanded radially the region of stored heat as thermal charging takes place in step 516. The rate of heating may be adjusted in this step. When energy charging is complete, the method switches to energy storage mode as in step 518. To use the energy stored, energy discharge takes in place in step 520. In this step, the air blower is reversed at 522 and steam is heated in steam generator. The speed of the air blower may be adjusted in this step. The rate of heating may also be adjusted in this step. In step 526, the steam is discharged to steam turbine, district heating, or other industrial processes. Once step 520 is complete, the method loops back to step 504.
While the foregoing written description enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The disclosure should therefore not be limited by the above-described embodiments, methods, and examples, but by all embodiments and methods within the scope and spirit of the disclosure.
This application claims priority to U.S. Provisional Application No. 63/348,444, filed on Jun. 2, 2022, which is incorporated herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63348444 | Jun 2022 | US |
