Systems, methods, and devices for steam production in a power plant using thermal energy storage

Abstract

In various aspects, a method for maintaining steam production in a power plant using heat from a thermal storage medium in lieu of heat obtained from burning natural gas in duct burners and / or a combustion or fission process may be provided. The method may include heating up a thermal storage medium with electric heater elements or hot fluids with a heat exchanger. The method may include storing heat in the thermal storage medium for a period of time. The method may include generating a hot working fluid by transferring stored heat from the thermal storage medium to a working fluid that passes through the thermal storage medium, by means of at least one of convection, conduction, radiation, and transferring heat to a steam generation system directly using radiation. The method may also include using energy of the hot working fluid to generate additional electricity through a steam turbine.

Description

[0001] Attorney Docket No.: Princeton - 103176

[0002] SYSTEMS, METHODS, AND DEVICES FOR STEAM PRODUCTION IN A POWER

[0003] PLANT USING THERMAL ENERGY STORAGE

[0004] CROSS-REFERENCE TO RELATED APPLICATIONS

[0005] The present application claims priority to U.S. Provisional Patent Application 63 / 685,323, filed August 21, 2024 and U.S. Provisional Patent Application 63 / 687,475. filed August 27. 2024. which is incorporated by reference herein by its entirety.

[0006] TECHNICAL FIELD

[0007] The present disclosure is drawn to systems, methods, and devices for steam production in a power plant.

[0008] BACKGROUND

[0009] This section is intended to introduce the reader to various aspects of the art, which maybe related to various aspects of the present disclosure that are described and / or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

[0010] The various aspects discussed herein relate to steam production in power plants, e.g., combined cycle gas turbine (CCGT) power plants. In CCGT power plants, a fuel, commonly natural gas, is burned in a combustion turbine to produce power. Exhaust gas from this combustion turbine is then directed to a heat recovery steam generator (HRSG) to produce steam for additional power generation from a steam turbine. Many CCGTs use duct burners, between the combustion turbine and steam turbine, to generate additional heat to allow the HRSG to increase or maintain steam production with the purpose of increasing power generated. In the United States, for example, about 75% of CCGT power plants use duct burners located between the combustion and steam turbine. The duct burning process leads to higher greenhouse gas emissions (CO2, CH4) and emissions of short-lived air pollutants such as (NOX, SO2). As such, there is a desire to increase power generated while simultaneously reducing greenhouse gas emissions. Attorney Docket No.: Princeton - 103176

[0011] BRIEF SUMMARY

[0012] Various deficiencies in the prior art are addressed below by the disclosed systems, methods, and devices for steam production.

[0013] In various aspects, a method for steam production in a power plant using heat from a thermal storage medium in lieu of heat obtained from burning natural gas in duct burners and / or a combustion or fission process may be provided. The method may include heating up a thermal storage medium with electric heater elements or hot fluids with a heat exchanger. The method may include storing heat in the thermal storage medium for a period of time. The method may include generating a hot working fluid by transferring stored heat from the thermal storage medium to a working fluid that passes through the thermal storage medium, by means of at least one of convection, conduction, radiation, and transferring heat to a steam generation system directly using radiation. The method may also include using energy of the hot working fluid to generate additional electricity through a steam turbine.

[0014] In some embodiments, generating additional electricity may include directing the hot working fluid to a heat recovery steam generator to generate steam or generating steam directly through the thermal storage medium. In some embodiments, the method may further include using a steam regulator and distributor to control steam flows and steam quality for steam generated directly through the thermal storage medium.

[0015] In some embodiments, the power plant may be at least one of a combined cycle gas turbine (CCGT) power plant, coal fired power plant, or a nuclear fission power plant.

[0016] In various aspects, a system for maintaining steam production in a power plant may be provided. The system may include a thermal storage system. The thermal storage system may include a vessel for containing a thermal storage medium. The thermal storage system may also include a thermal storage medium heating subsystem configured to be operably coupled to a generator coupled to a substation coupled to a high-voltage transmission grid and / or a combustion turbine or steam turbine. The thermal storage medium heating subsystem may include heater elements configured to receive electricity from the substation and / or generator to heat up the thermal storage medium and / or a heat exchanger configured to receive a hot fluid.

[0017] The thermal storage system may also include a working fluid input and a working fluid output. The working fluid input may be configured to receive a working fluid at a first temperature. The working fluid output may be configured to output the working fluid at a second temperature greater than the first temperature. The output from the thermal storage system may be configured to be coupled to a heat recovery steam generator or a steam turbine. Attorney Docket No.: Princeton - 103176

[0018] In some embodiments, the working fluid may be a liquid at a standard temperature and pressure. In some embodiments, the working fluid may be a vapor at standard temperature and pressure. In some embodiments, the working fluid may be either air, supercritical CO2 or water. In some embodiments, the output from the thermal storage system may be coupled to the steam turbine. The system may further include a steam regulator and distributor to control steam flows and steam quality from the thermal storage system to the steam turbine.

[0019] In some embodiments, the system may further include a combustion turbine operably coupled to a first electricity generator. The combustion turbine may be configured to receive a fuel from a fuel source. The system may further include a heat recovery steam generator. The heat recovery steam generator may be configured to receive exhaust gases or waste heat from the combustion turbine and generate steam. The system may further include a steam turbine operably coupled to a second electricity generator. The steam turbine may be configured to receive steam from the heat recovery steam generator.

[0020] In some embodiments, the system may further include thermal insulation around at least a portion of the thermal storage system.

[0021] In various aspects, an integrated heat exchanger may be provided. The integrated heat exchanger may include a solid energy storage core including a plurality of openings extending therethrough from a first outer surface to a second outer surface. The solid energy storage core may be formed by a thermal storage material. In some embodiments, the integrated heat exchanger may include piping disposed within the plurality of openings. The piping may include an inlet and an outlet.

[0022] In some embodiments, the thermal storage material may be composed of graphite, a graphite-based composite material, a cementitious composite material, or cement. The thermal storage material may be composed of a thermal storage material other than graphite, a graphitebased material, a cementitious composite material, or cement. In some embodiments, the piping may form a single flow channel from inlet to outlet. The piping may form a plurality of flow channels. Each flow channel may be coupled to the inlet and outlet. The piping may be directly- bonded to the thermal storage material.

[0023] In some embodiments, within each flow channel, there may be a gap between an outer surface of the piping and an inner surface of the thermal storage material forming each opening. Each gap may be filled with an intermediary- heat transfer fluid. The intermediary- heat transfer fluid may be helium, a high thermal conductivity liquid, or a combination thereof.

[0024] In some embodiments, the piping may be composed of a high-temperature, oxidationresistant metal, ceramic, or composite. The piping may be composed of a stainless steel, an Attorney Docket No.: Princeton - 103176

[0025] Inconel alloy, a Haynes alloy, niobium alloy, tungsten alloy. Alumina-Forming Austenitic Stainless Steels, a Ni-Cr alloy or nickel aluminide. The piping may be composed of a ferrous or non-ferrous metal. The piping may be configured to be removable from the plurality of openings.

[0026] In various aspects, a heat exchanger system may be provided. The heat exchanger system may include at least one integrated heat exchanger as described herein. The heat exchanger system may further include a means for heating the thermal storage material.

[0027] In some embodiments, the means for heating the thermal storage material may include joule heating elements disposed around the thermal storage material that heat the thermal storage material by radiation, conduction, or both. The thermal storage material may be composed of an electrically conductive material. The means for heating the thermal storage material may include resistive heating of the electrically conductive material.

[0028] In some embodiments, the means for heating the thermal storage material may include a heat transfer fluid configured to heat the thermal storage material by means of the integrated heat exchanger.

[0029] In some embodiments, the integrated heat exchanger may be configured to transfer heat from the thermal storage material to each flow channel by direct conduction, convection through an intermediary heat transfer fluid, radiation, or a combination thereof.

[0030] In some embodiments, the at least one integrated heat exchanger may include a single integrated heat exchanger. The at least one integrated heat exchanger may include a plurality of integrated heat exchangers, The plurality of integrated heat exchangers may be arranged in series or parallel.

[0031] In some embodiments, the system may further include a fluid disposed within the piping. The fluid may be liquid water at an input to the at least one integrated heat exchanger and steam at an elevated temperature at an output from the at least one integrated heat exchanger.

[0032] In some embodiments, the system may further include a controller configured to regulate fluid flow rate, pressure, residence time, or a combination thereof through the piping to provide steam at the output at a desired fluid pressure and temperature. The system may further include one or more sensors operably coupled to the controller. The one or more sensors may be configured to provide at least a fluid temperature and pressure at the output of the heat exchanger system. The system may further include at least one bypass loop operably coupled to the inlet and outlet of the at least one integrated heat exchanger. Attorney Docket No.: Princeton - 103176

[0033] In various aspects, a method for heat exchanger may be provided. The method may include heating a thermal storage medium. The method may also include transferring heat from the thermal storage medium to a fluid within piping that extends through openings within the thermal storage medium. Heat may be transferred to the fluid via direct conduction, convection through an intermediary7heat transfer fluid, radiation, or a combination thereof.

[0034] In some embodiments, the method may further include providing the fluid to the piping at a supercritical inlet pressure.

[0035] In some embodiments, the method may further include controlling fluid flow7rate, pressure residence time, or a combination thereof of the fluid within the piping to achieve a target output. In some embodiments, the target output may be steam with a fixed constant temperature and a fixed constant pressure. The fixed constant temperature may be a temperature of 100°C-1000°C. The fixed constant pressure may be a pressure of 1-200 bar.

[0036] The target output may be steam with varying temperatures and pressures. The temperatures may be within 200°C-700°C and pressures being 1-200 bar.

[0037] In various aspects a method for maintaining steam production in a power plant using heat from a hot working fluid in heu of heat obtained from burning natural gas in duct burners and / or a combustion or fission process may be provided. The method may include providing an integrated heat exchanger as described herein. The method may also include heating up the thermal storage material using heater elements or hot fluids with the integrated heat exchanger. The method may also include storing heat in the thermal storage material for a period of time. The method may also include generating a hot working fluid by transferring stored heat from the thermal storage material to a w orking fluid that passes through the thermal storage material, by means of at least one of convection, conduction, radiation, and transferring heat to a steam generation system directly using radiation. The method may also include using heat of the hot w orking fluid to generate additional electricity7through a steam turbine.

[0038] In some embodiments, generating additional electricity7may include directing the hot working fluid to a heat recovery7steam generator to generate steam or generating steam directly through the thermal storage material. The method may further include using a steam regulator and distributor to control steam flows and steam quality for steam generated directly through the thermal storage material.

[0039] In some embodiments, the powder plant may be a combined cycle gas turbine (CCGT) power plant, coal fired power plant, or a nuclear fission power plant.

[0040] In various aspects, a system for maintaining steam production in a power plant using heat from a hot working fluid in lieu of heat obtained from burning natural gas in duct burners Attorney Docket No.: Princeton - 103176 and / or a combustion or fission process may be provided. The system may include a thermal storage system. The thermal storage system may include a vessel for containing an integrated heat exchanger. The thermal storage system may also include an integrated heat exchanger as described herein. The integrated heat exchanger may be configured to be operably coupled to a combustion turbine or generator coupled to the combustion turbine. The integrated heat exchanger may be configured to receive a hot fluid from the combustion turbine to heat up the thermal storage material. The output of the integrated heat exchanger may be configured to be coupled to a heat recovery steam generator or steam turbine.

[0041] In some embodiments, the hot fluid may be a liquid at standard temperature and pressure. The hot fluid may be a vapor at standard temperature and pressure. The hot fluid may be air, supercritical CO2 or water.

[0042] In some embodiments, the output from the thermal storage system may be coupled to the steam turbine. The system may further include a steam regulator and distributor to control steam flows and steam quality from the thermal storage system to the steam turbine.

[0043] In some embodiments, the system may further include a combustion turbine operably coupled to a first electricity generator. The combustion turbine may be configured to receive fuel from a fuel source. The system may further include a heat recovery steam generator configured to receive exhaust gases or waste heat from the combustion turbine and generate steam. The system may further include a steam turbine operably coupled to a second electricity generator. The steam turbine may be configured to receive steam from the heat recovery steam generator.

[0044] In some embodiments, the system may further include thermal insulation around at least a portion of the thermal storage system.

[0045] In some embodiments, the system may include at least one sensor operably coupled to the outlet of the integrated heat exchanger. In some embodiments, the at least one sensor may be configured to measure a temperature of the hot fluid. In some embodiments, the at least one sensor may be configured to measure a pressure of the hot fluid.

[0046] In some embodiments, the system may further include a non-transitory computer- readable medium operably coupled to at least one processor. The at least one processor and non-transitory computer-readable medium may be configured to receive measurements from a plurality of sensors. The at least one processor may be configured to control temperature of the hot fluid according to the measurements. The at least one processor may be configured to control pressure of the hot fluid according to the measurements. Attorney Docket No.: Princeton - 103176

[0047] Additional objects, advantages, and novel features of the present disclosure will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the present disclosure. The objects and advantages of the present disclosure may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

[0048] BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with a general description of the present disclosure given above, and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure.

[0050] Figure 1 shows a flow diagram of an embodiment of a method for steam production in a power plant using heat from a thermal storage medium in lieu of heat obtained from burning natural gas in duct burners and / or a combustion or fission process

[0051] Figures 2A and 2B show a block diagram of an embodiment of a system for maintaining steam production in a power plant.

[0052] Figure 3 shows a cross-sectional view of an embodiment of an integrated heat exchanger with a close-up view of an opening.

[0053] Figure 4 shows an isometric view of an embodiment of piping.

[0054] Figure 5A shows a cross-sectional view of an embodiment of an integrated heat exchanger using a single channel liquid tube.

[0055] Figure 5B shows a cross-sectional view of an embodiment of an integrated heat exchanger using a single channel liquid tube.

[0056] Figure 6A shows a cross-sectional view of an embodiment of an integrated heat exchanger using an arrangement of parallel liquid tubes.

[0057] Figure 6B shows a cross-sectional view of an embodiment of an integrated heat exchanger using an arrangement of parallel liquid tubes.

[0058] Figures 7A-7C show cross-sectional views of an embodiment of an integrated heat exchanger.

[0059] Figure 7D shows a cross-sectional view of an embodiment of an integrated heat exchanger from cutting plane A of FIG. 7C.

[0060] Figure 8 shows a flow diagram of an embodiment of a method for heat exchanger. Attorney Docket No.: Princeton - 103176

[0061] Figure 9 shows a flow diagram of an embodiment of a method for steam production using heat from a hot working fluid in lieu of heat obtained from burning natural gas in duct burners and / or a combustion or fission process.

[0062] Figure 10 shows a block diagram of an embodiment of a system for maintaining steam production in a power plant with an integrated heat exchanger.

[0063] Figure 11 shows a block diagram of a computing environment.

[0064] Figure 12 shows a block diagram of an embodiment of a system for maintaining steam production in a power plant.

[0065] It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the sequence of operations as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes of various illustrated components, will be determined in part by the particular intended application and use environment. Certain features of the illustrated embodiments have been enlarged or distorted relative to others to facilitate visualization and clear understanding. In particular, thin features may be thickened, for example, for clarity or illustration.

[0066] DETAILED DESCRIPTION OF THE INVENTION

[0067] The following drawings merely illustrate the principles of the present disclosure. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the present disclosure and are included within its scope. Furthermore, all examples recited herein are principally intended expressly to be only for illustrative purposes to aid the reader in understanding the principles of the present disclosure and the concepts contributed by the inventors to furthering the art and are to be construed as being without limitation to such specifically recited examples and conditions. Additionally, the term, “or,” as used herein, refers to anon-exclusive or, unless otherwise indicated (e.g., “or else” or “or in the alternative”). Also, the various embodiments, described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments.

[0068] The numerous innovative teachings of the present disclosure will be described with particular reference to the presently preferred exemplary' embodiments. However, it should be understood that this class of embodiments provides only a few examples of the many advantageous uses of the innovative teachings herein. In general, statements made in the Attorney Docket No.: Princeton - 103176 specification of the present application do not necessarily limit any of the various claimed inventions. Moreover, some statements may apply to some inventive features but not to others. Those skilled in the art and informed by the teachings herein will realize that the invention is also applicable to other technical areas or embodiments.

[0069] Steam is conventionally generated through the burning of fossil fuels (e.g., coal, natural gas). Burning fossil fuels leads to higher greenhouse gas emissions (CO2, CH4) and emissions of short-lived air pollutants such as NO2 & SO2. It is also expensive. Thermal Energy Storage (TES) when partnered with steam generation offers a new pathway to store excess electricity or heat when economically favorable, and to dispatch this heat in the form of steam for pow er generation or industrial processes at the most optimal periods for costs and emissions reductions.

[0070] Several approaches to high-temperature thermal energy storage have been proposed. For example, one proposal includes an arrangement of electrically conductive refractory bricks that can be charged through Joule heating principles. This raises the temperatures of the bricks and this energy can be stored as thermal energy until it is needed, at which time air can be blown through the system to transfer the heat away from the brickwork. For steam to be produced from such a system, the hot air would need to be run through a heat exchanger.

[0071] Another proposal includes a thermal energy' storage system with energy' stored in firebricks. The bricks are heated radiatively through heater elements placed throughout the brickwork and configured to allow for heat transfer to a working fluid (e.g., air) that would be blown through channels in the brickwork for heat transfer. As described in that proposal, this hot fluid can then be dispatched to a heat exchanger for producing steam as needed.

[0072] While these approaches are functionally capable, their operation requires integration with a secondary’ system, i.e.. a heat exchanger, in order to produce steam for an industrial process or power plant. This often increases system complexity, requires expensive construction work (e.g., ducting), and reduces the modularity of the system. As the heat exchanger piping must be gradually warmed up to prevent thermal shock and cracks in the metal piping, these systems are also slower to generate steam and will be limited in their response time to operating requirements. This is particularly challenging for power plants where increasing penetration of renewable energy' requires increased flexibility from thermal power plants on the grid. As renewable energy' resources such as wind and solar power are weather-dependent, thermal power plants need to respond quickly to grid conditions.

[0073] These approaches are unable to address these issues as they rely on integration with secondary, conventional heat exchangers. Finally, as the approaches described above rely on a Attorney Docket No.: Princeton - 103176 primary fluid (e.g., air) to transfer heat away from the thermal storage medium to the secondary heat exchanger, they must make use of large blowers and compressors that end up increasing system cost through both additional capital cost for these components and operation cost in terms of electrical loads and maintenance. The latter is particularly acute in the case of using air as a working fluid given its poor thermal conductivity'. Therefore, there is a desire to: (1) reduce the start-up time for steam generation systems, (2) reduce the cost of thermal storage systems for steam generation, and (3) improve the efficiency of heat transfer in thermal storage systems from the thermal storage medium to the working fluid.

[0074] According to some embodiments of the disclosed approach, a once-through steam generator may be embedded into a thermal storage unit. This differs from other thermal energy storage (TES) systems that use an intermediary high-temperature fluid (HTF) that is subsequently expelled from the TES unit and passed through a secondary loop with a heat exchanger to generate steam. By removing this intermediate step, one achieves a significant reduction in system complexity, number of mechanical parts (valves, seals, etc.), and piping (and associated costs), while also providing a step improvement in the responsiveness during the production of steam. Depending on the application, one can also use supercritical internal pressures for the water / steam pipes so that one can achieve a marked increase in steam generation efficiency.

[0075] The TES all-in-one steam generator may also be split into multiple stages and piped in series to reduce the overall change in temperature between inlet and outlet which will help to reduce the thermal load cycles. The unit can also be fed with lower grade steam where the once- through piping works as a superheater to raise the temperature to required levels. Finally, for the lower temperature stages, the unit can also be used in reverse where waste steam (or any other HTF) is pumped through and used to heat the thermal storage medium. In this case the unit works as a condenser to extract useful energy left in the HTF.

[0076] It is also envisioned that the various disclosed embodiments may be utilized as a plug and play unit that can be dropped into any site which alloyvs such facilities to keep much of their existing infrastructure (e.g., turbines), but simply replaces the steam from the expensive and emissions intensive burning of fossil fuels.

[0077] In addition, the various disclosed approaches work with any solid TES medium and heating method (e.g., joule heating / HTF heating / induction heating etc.) and takes feedwater straight into the unit. This feedwater is pressurized to the desired pressure and is sent through piping that may serpentine around the thermal storage medium. Attorney Docket No.: Princeton - 103176

[0078] The various embodiments described below provide solutions to several needs. For example, the disclosed systems and methods could be used by combined cycle natural gas power plants that are located across the world including 278,000 MW of CCGT capacity in the United States. Among other things, the disclosed approach allows such facilities to keep their existing infrastructure, but simply replaces the heat from expensive and emissions intensive duct burning of natural gas. It is estimated that replacing duct burning at combined cycle power plants with thermal storage based zero emissions heat has the potential to reduce emissions by up to 25 million tons of CO2 per year in the United States alone.

[0079] Referring now to FIG. 1 , an embodiment of a method for steam production in a power plant using heat from a thermal storage medium in lieu of heat obtained from burning natural gas in duct burners and / or a combustion or fission process (100) is shown. The method may include heating (110) up a thermal storage medium with electric heater elements or hot fluids with a heat exchanger. The method may include storing (120) heat in the thermal storage medium for a period of time. The method may also include generating (130) a hot working fluid by transferring stored heat from the thermal storage medium to a working fluid that passes through the thermal storage medium, by means of at least one of convection, conduction, radiation, and transferring heat to a steam generation system directly using radiation. The method may also include using (140) energy7of the hot working fluid to generate additional electricity through a steam turbine.

[0080] In some embodiments, generating additional electricity includes directing the hot working fluid to a heat recovery steam generator to generate steam or generating steam directly through the thermal storage medium. In some embodiments, the method may further include using a steam regulator and distributor to control steam flows and steam quality7for steam generated directly through the thermal storage medium.

[0081] In some embodiments, the power plant may be at least one of a combined cycle gas turbine power plant, a coal-fired power plant, a nuclear fission power plant, or a geothermal power plant.

[0082] Referring now to FIG. 2A, a block diagram of an embodiment of a system for maintaining steam production in a power plant (200) is shown. As shown, the system may include a thermal storage system (250). The thermal storage system may include a vessel (252) for containing a thermal storage medium. The thermal storage system may include a thermal storage medium heating subsystem (255) configured to be operably coupled to a generator coupled to a substation coupled to a high-voltage transmission grid and / or a combustion turbine or, as shown in FIG. 2A, a steam turbine, the thermal storage medium heating subsystem may Attorney Docket No.: Princeton - 103176 include heater elements configured to receive electricity from the substation and / or generator to heat up the thermal storage medium and / or a heat exchanger configured to receive a hot fluid.

[0083] The thermal storage system may also include a working fluid input (254) and working fluid output (256). The working fluid input may be configured to receive a working fluid at a first temperature. The working fluid output may be configured to output the working fluid at a second temperature. The second temperature may be greater than the first temperature. The output from the thermal storage system may be configured to be coupled to a heat recovery steam generator or steam turbine.

[0084] In some embodiments, the working fluid may be a liquid at a standard temperature and pressure (i.e., 20°C and 1 bar). In some embodiments, the working fluid may be a vapor at standard temperature and pressure. In some embodiments, the working fluid may be air, or supercritical CO2 or water. In some embodiments, the output from the thermal storage system may be coupled to the steam turbine (240). The system may further include a steam regulator (270) and distributor to control steam flows and steam quality from the thermal storage system to the steam turbine.

[0085] The term “steam turbine” as used herein, may refer to conventional steam turbines. However, those skilled in the art and informed by the teachings herein will appreciate that “steam turbine” may correspond to other turbine systems depending on the utilized fluids. For example, in cases where the working fluid is supercritical CO2, the steam turbine may be a CO2 turbine.

[0086] In some embodiments, the system may further include a combustion turbine (220). The combustion turbine may be operably coupled to a first electricity generator (212). The combustion turbine may be configured to receive fuel from a fuel source (225). The system may further include a heat recovery steam generator (230). The heat recover}' steam generator may be configured to receive exhaust gases or waste heat from the combustion turbine and generate steam. The system may further include a steam turbine (240). The steam turbine may be operably coupled to a second electricity generator (214). The steam turbine may be configured to receive steam from the heat recovery steam generator.

[0087] In some embodiments, the system may further include thermal insulation around at least a portion of the thermal storage system to increase the longevity of the heat storage.

[0088] Referring briefly to FIG. 2B, a block diagram of an alternative embodiment of the system for maintaining steam production in a power plant is shown. In this embodiment, the Attorney Docket No.: Princeton - 103176 thermal storage system may be operably coupled to the heat recovery steam generator as opposed to the steam turbine, as shown in FIG. 2A.

[0089] Referring now to FIG. 3, a cross-sectional view of an embodiment of an integrated heat exchanger (300) is shown. The integrated heat exchanger may include a solid energy storage core (310). The solid energy storage core may include a plurality of openings (320) extending therethrough from a first outer surface (330) to a second outer surface (340). The solid energy storage core may be composed of a thermal storage material.

[0090] In some embodiments, the thermal storage material may be composed of graphite, a graphite-based composite material, a cementitious composite material, or cement. The thermal storage material may be composed of a thermal storage material other than graphite, a graphitebased material, a cementitious composite material, or cement.

[0091] The integrated heat exchanger may also include piping (350) disposed within the plurality of openings. The piping may include an inlet (354) and an outlet (356). In some embodiments, the piping may be configured to be removable from the solid energy7storage core.

[0092] Referring briefly to FIG. 4, an isometric view of an embodiment of piping is shown. The piping may include one or more segments (352). Each of the one or more segments (352) may be separated by a segmentation point (355). The segmentation point may provide a connection between each of the one or more segments. The segmentation point may be configured as a coupling, joint or sleeve. For example, the segmentation point may be a mechanical connector, such as a threaded fitting, clamp, or compression joint, that allows adj acent segments to be removably coupled to one another. The removabi li ty of the piping may allow for routine maintenance and / or easy replacement.

[0093] Referring briefly to FIG. 5A and FIG. 5B. the piping may form a single flow channel from inlet to outlet. As shown in FIG. 5B, the single flow channel piping may be weaved through the plurality of openings from inlet to outlet.

[0094] Referring now7to FIG. 6A and FIG. 6B, a cross-sectional view of another embodiment of an integrated heat exchanger is shown. In this embodiment the piping of the integrated heat exchanger forms a plurality of flow channels (612-A), (612-B). Each flow channel is coupled to the inlet (354) and the outlet (356). While only a single inlet and outlet are shown, those skilled in the art and informed by the teachings herein will appreciate that there may be a plurality of inlets and outlets.

[0095] In some embodiments, the piping may be directly bonded to the thermal storage material. As one example, the piping may be thermally bonded to the thermal storage material Attorney Docket No.: Princeton - 103176 by heating the piping to a temperature sufficient to create bonding between the piping surface and the thermal storage material. This bonding may create a metallurgical bond that enhances the heat transfer efficiency. In some embodiments, the piping may be bonded to the thermal storage material by an adhesive. A thermally conductive adhesive may be applied between the outer surface of the piping and the inner surface of the plurality of openings. The adhesive maybe a high-temperature ceramic adhesive, a carbon-based adhesive, or a metallic adhesive compatible with both the piping material and the thermal storage material.

[0096] In embodiments where the thermal storage material is a cementitious material, the piping may be positioned within the plurality of openings before the cementitious material is cured. During the curing process, the cementitious material may form a mechanical and / or chemical bond with the outer surface of the piping. In some embodiments, the outer surface of the piping may be treated with a bonding agent or surface preparation that enhances chemical adhesion with the cementitious composite material. The bonding agent may comprise silane coupling agents, epoxy primers, or other chemical compounds that promote adhesion between the piping material and the cementitious matrix.

[0097] In some embodiments the piping may include surface features such as ridges, grooves, or textured surfaces that provide mechanical interlocking with the cementitious composite material. These mechanical features increase the bonding strength and prevent relative movement between the piping and the thermal storage material.

[0098] In some embodiments, regardless of thermal storage material composition, the piping may be bonded through brazing or welding. Where compatible materials are used, the piping may be brazed or welded to metallic components embedded within or attached to the thermal storage material, creating a permanent metallurgical bond. In some embodiments, the piping may be secured using compression fittings that mechanically clamp the piping against the thermal storage material within the plurality of openings. The piping may be installed at a lower temperature than the operating temperature, such that thermal expansion or contraction during operation creates or enhances the bonding force between the piping and the thermal storage material.

[0099] Referring back to FIG. 3, in some embodiments, within each flow channel, there may be a gap (325) between an outer surface (358) of the piping (350) and an inner surface (360) of the thermal storage material forming each opening. In some embodiments, the gap may be filled with an intermediary heat transfer fluid (e.g., helium). A distance of the gap, d, may be between about 100 pm to 10 cm. The distance may be between about 500 pm to 5 cm. The distance may be between about 1 mm to 1 cm. Attorney Docket No.: Princeton - 103176

[0100] The intermediary heat transfer fluid (e.g., helium, a high thermal conductivity liquid, or combination thereof) may act as a Thermal transistor’. The thermal transistor may serve to regulate the heat transfer from the thermal storage medium to the piping where the working fluid is contained. When the gap is filled with the heat transfer fluid, heat is transferred readily across the gap due to the thermal bridge. When the gap is void of the intermediate heat transfer fluid, heat transfer is minimized and dominated by radiation from the thermal storage material rather than the combination of conduction, convection, and radiation. This can be used to sen e as an “on-off’ switch for heat exchange or to moderate the discharge rate of heat into the working fluid based on the output conditions of the working fluid.

[0101] Varied partial pressures and gas mixtures containing the heat transfer fluid may be selected for the desired properties of the thermal bridge (combinations of He, Argon. Air, N2). In the case of Helium, Helium’s thermal conductivity, largely insensitive to partial pressure, presents a particularly attractive option for the thermal transistor.

[0102] The strength of the thermal transistor can be regulated by pumping systems, for example the system may be first purged down to vacuum or a fluid with low thermal conductivity, then backfilled with the desired heat transfer fluid that increases the rate of heat transfer. In some embodiments, other thermal transitory fluids may include thermally conductive liquids such as liquid metals (e.g., mercury ) or other working fluids.

[0103] One can imagine a situation where a power plant must rapidly switch on and dispatch power to respond to grid conditions. In such a case, relying on radiation alone will result in slower heat transfer between the thermal storage material and the piping, therefore resulting in slower ‘switch-on’ of the pow er plant to generate steam through the device. Instead, pumping the system with an intermediary heat transfer fluid to activate the thermal transistor allows for heat transfer to proceed through a combination of convection, radiation, and conduction, speeding up the time to power production.

[0104] Those skilled in the art will appreciate, such a gap between the thermal storage material and piping may also deliver mechanical benefits, for example, by reducing thermal stresses from mismatch of coefficient of thermal expansion (CTE) for differing materials for the thermal storage medium and piping.

[0105] In some embodiments, the piping may be composed of a high-temperature, oxidationresistant metal, ceramic, or composite. Non-limiting examples of the composition of the piping may include a stainless steel, an Inconel alloy, a Haynes alloy, Alumina-Forming Austenitic Stainless Steels, a Ni-Cr alloy, or nickel aluminide. The piping may be composed of a ferrous Attorney Docket No.: Princeton - 103176 or non-ferrous metal. The piping may be coated or uncoated for oxidation and corrosion resistance.

[0106] In various aspects, a heat exchanger system may be provided. The heat exchanger system may include at least one integrated heat exchanger as described herein. The heat exchanger system may also include a means for heating the thermal storage material.

[0107] In some embodiments, the means for heating the thermal storage material may include joule heating elements. The joule heating elements may be disposed around the thermal storage material and heat the thermal storage material by radiation, conduction, or both.

[0108] The thermal storage material may be composed of an electrically conductive material. Non-limiting examples of the electrically conductive material may include copper, aluminum, silver, gold, chromium, platinum, nickel, or iron. The electrically conductive material may be a metallic alloy, such as, stainless steel, carbon steel, brass (copper-zinc alloy), bronze (coppertin alloy), an Inconel alloy, a Haynes alloy, or Alumina-Forming Austenitic Stainless Steels, or other metallic oxides, carbides or nitrides. The electrically conductive material may be a carbon-based material, for example, a graphitic material.

[0109] In some embodiments, the electrically conductive material may be a conductive ceramic or composite. For example, the conductive ceramics may include titanium carbide, tungsten carbide, tantalum carbide, niobium carbide, or titanium nitride. The conductive composite may be a metal-filled polymer, carbon fiber reinforced composite, or graphite-filled ceramic.

[0110] In some embodiments, when the thermal storage material is composed of an electrically conductive material, the means for heating the thermal storage material may include resistive heating of the electrically conductive material.

[0111] In some embodiments, the means for heating the thermal storage material may include a heat transfer fluid configured to heat the thermal storage material by means of the integrated heat exchanger. The heat exchanger system may be configured to heat the thermal storage material by means of the integrated heat exchanger. The heat exchanger system may be configured to transfer heat from the thermal storage material to each flow channel by direct conduction, convection through an intermediary heat transfer fluid, radiation, or a combination thereof.

[0112] In some embodiments, the at least one integrated heat exchanger may include a single integrated heat exchanger. The at least one integrated heat exchanger may include a plurality of integrated heat exchangers arranged in series. The plurality of integrated heat exchangers Attorney Docket No.: Princeton - 103176 may be arranged in parallel. The plurality of integrated heat exchangers may be arranged in a combination of series and parallel.

[0113] The system may further include a fluid disposed within the piping. The fluid may be air, supercritical CO2 or water. The fluid may be a vapor (e.g., water vapor). The fluid may be liquid water at an input to the at least one integrated heat exchanger and steam at an elevated temperature at an output from the at least one integrated heat exchanger.

[0114] In some embodiments, the heat exchanger system may further include a controller configured to regulate fluid flow rate, pressure, residence time, or a combination thereof through the piping to provide steam at the output at a desired fluid pressure and temperature. In some embodiments, the heat exchanger system may further include one or more sensors operably coupled to the controller. The one or more sensors may be configured to provide at least a fluid temperature and pressure at the output of the heat exchanger system. In some embodiments, the system may further include at least one bypass loop operably coupled to the inlet and outlet of the at least one integrated heat exchanger.

[0115] FIG. 7A. FIG. 7B, and FIG. 7C show another embodiment of an integrated heat exchanger. Referring briefly to FIG. 7D, a cross-sectional view of an embodiment of an integrated heat exchanger from cutting plane A of FIG. 7C is shown. As show n in FIG. 7D, the integrated heat exchanger may also include a controller (390) operably coupled to the integrated heat exchanger. Although the controller is shown as being physically connected to the integrated heat exchanger, it is envisioned the controller may be wirelessly coupled to the integrated heat exchanger. The controller may be configured to adjust and control various parameters within the integrated heat exchanger, for example flow rate and / or pressure.

[0116] Referring now to FIG. 8, a flow diagram of an embodiment of a method for heat exchanger (800) is shown. The method may include heating (810) a thermal storage medium. The method may also include transferring (820) heat from the thermal storage medium to a fluid within piping that extends through openings within the thermal storage medium, heat being transferred to the fluid via direct conduction, convection through an intermediary heat transfer fluid, radiation, or a combination thereof.

[0117] In some embodiments, the method may further include providing the fluid to the piping at a supercritical inlet pressure.

[0118] In some embodiments, the method may further include controlling fluid flow rate, pressure, residence time, or a combination thereof of the fluid within the piping to achieve a target output. The target output may be steam with a fixed constant temperature and a fixed constant pressure. The fixed constant temperature may be a temperature between about 1°C- Attorney Docket No.: Princeton - 103176

[0119] 1000°C. The fixed constant temperature may be a temperature between about 50°C-900°C. The fixed constant temperature may be between about 100°C-800°C. The fixed constant temperature may be between about 250°C-750°C. The fixed constant temperature may be between about 300°C-700°C.

[0120] The fixed constant pressure may be between about 0.01 bar to 1000 bar. The fixed constant pressure may be between about 0.05 bar and 500 bar. The fixed constant pressure may be between about 0.1 bar and 400 bar. The fixed constant pressure may be between about 0.5 bar and 300 bar. The fixed constant pressure may be between about 1 bar and 150 bar.

[0121] In some embodiments, the target output may be steam with varying temperatures and pressures. The temperatures may be within about 200°C-700°C. The pressures may be within about 1 bar and 200 bar.

[0122] Referring now to FIG. 9, a flow-diagram of an embodiment of a method for steam production in a power plant using heat from a hot working fluid in lieu of heat obtained from burning natural gas in duct burners and / or a combustion or fission process (900) is shown. The method may include providing (910) an integrated heat exchanger as described herein. The method may include heating up (920) the thermal storage material with heater elements or hot fluids with the integrated heat exchanger. The method may also include storing (930) heat in the thermal storage material for a period of time. The method may include generating (940) a hot working fluid by transferring stored heat from the thermal storage material to a working fluid that passes through the thermal storage material, by means of at least one of convection, conduction, radiation, and transferring heat to a steam generation system directly using radiation. The method may also include using (950) heat of the hot working fluid to generate additional electricity through a steam turbine.

[0123] In some embodiments, generating additional electricity may include directing the hot w orking fluid to a heat recovery steam generator to generate steam or generating steam directly through the thermal storage material. The method may further include using a steam regulator and distributor to control steam flow s and steam quality' for steam generated directly through the thermal storage material.

[0124] In some embodiments, the power plant may be a combined cycle gas turbine power plant. Those skilled in the art and informed by the teachings herein will appreciate that the power plant may be any suitable power plant, which may include, for example, a coal-fired power plant, a nuclear fission power plant, or a geothermal power plant.

[0125] Referring now to FIG. 10, a block diagram of a system (1000) for maintaining steam production in a power plant that is free of a duct burner is shown. The system may include a Attorney Docket No.: Princeton - 103176 thermal storage system (1050). The thermal storage system may include a vessel (1052) for containing an integrated heat exchanger (1055). The thermal storage system may also include an integrated heat exchanger (1055) as described herein. While the vessel in FIG. 10 is shown as only holding a single integrated heat exchanger, it is envisioned that the vessel may be configured to hold a plurality' of integrated heat exchangers, for example, the vessel may hold three integrated heat exchangers. In embodiments where a plurality of integrated heat exchangers are utilized, the integrated heat exchangers may be arranged in series, parallel, or a combination thereof. The output of the integrated heat exchanger may be configured to be coupled to a heat recovery steam generator or steam turbine.

[0126] In some embodiments, the hot fluid may be a liquid at standard temperature and pressure. The hot fluid may be a vapor at standard temperature and pressure. The hot fluid may be air, supercritical CO2 or water.

[0127] In some embodiments, the output from the thermal storage system may be coupled to the steam turbine. The system may further include a steam regulator and distributor to control steam flows and steam quality from the thermal storage system to the steam turbine.

[0128] In some embodiments, an output from the thermal storage system may be situated to facilitate steam jet cooling to cool water or other fluid media. Here, a steam-jet refrigeration uses a high-pressure steam nozzle to create a deep vacuum over a water pool. Under vacuum, the water “flashes’' (evaporates) at a low temperature, absorbing heat and making chilled water. The vapor is entrained by the steam jet and condensed in a heat exchanger. Such cooling may be used for cooling data centers or other intensive applications.

[0129] Still referring to FIG. 10, the system may further include a combustion turbine (1020) operably coupled to a first electricity generator (1012). The combustion turbine may be configured to receive fuel from a fuel source (1025). The system may further include a heat recovery steam generator (1030). The heat recovery steam generator may be configured to receive exhaust gases or w aste heat from the combustion turbine and generate steam.

[0130] The system may further include a steam turbine (1040). The steam turbine may be operably coupled to a second electricity’ generator (1014). The steam turbine may be configured to receive steam, from the heat recovery steam generator.

[0131] In some embodiments, the system may further include thermal insulation around at least a portion of the thermal storage system. The system may further include at least one sensor operably coupled to the outlet of the integrated heat exchanger. The at least one sensor may be configured to measure a temperature of the hot fluid. The at least one sensor may be configured to measure a pressure of the hot fluid. Attorney Docket No.: Princeton - 103176

[0132] In some embodiments, the system may further include a non-transitory computer- readable medium operably coupled to at least one processor. The at least one processor and non-transitory computer-readable medium may be configured to receive measurements from a plurality of sensors. The at least one processor may be configured to control temperature of the hot fluid according to the measurements. The at least one processor may be configured to control pressure of the hot fluid according to the measurements.

[0133] Refernng now to FIG. 11. a high-level block diagram of a computing device suitable for use within the context of the various embodiments are shown. It is contemplated that the various systems and methods may be implemented via a computing device. That is, the various methods for maintaining steam production in a power plant may utilize a computing device in various embodiments e.g.. for controlling or optimizing a fluid flow rate, pressure, residence time, or a combination thereof of the fluid within the piping to achieve a target output. As depicted in FIG. 11, a computing device (1100) includes a processor element (1103) (e.g., a central processing unit (CPU) and / or other suitable processor(s)), a memory7(1104) (e.g., random access memory (RAM), read only memory7(ROM), and the like), a cooperating module / process (1105), and various input / output device (1106) (e.g., a user input device (such as a keyboard, a keypad, a mouse, and the like), a user output device (such as a display, a speaker, and the like), an input port, an output port, a receiver, a transmitter, and storage devices (e.g., a persistent solid state drive, a hard disk drive, a compact disk drive, and the like)).

[0134] It will be appreciated that the functions depicted and described herein may be implemented in hardware and / or in combination of software and hardware, e.g., using a general-purpose computer, one or more application specific integrated circuits (ASIC), and / or any other hardware equivalents. In one embodiment, the cooperating process (1105) can be loaded into memory (1104) and executed by processor (1103) to implement the functions as discussed herein. Thus, cooperating process (1105) (including associated data structures) can be stored on a computer readable storage medium, e.g., RAM memory, magnetic or optical drive, or diskette, and the like.

[0135] It is contemplated that some of the steps discussed herein may be implemented within hardware, for example, as circuitry that cooperates with the processor to perform various method steps. Portions of the functions / elements described herein may be implemented as a computer program product wherein computer instructions, when processed by a computing device, adapt the operation of the computing device, the various systems for maintaining steam production in a power plant, and / or integrated heat exchangers. Instructions for invoking the methods may be stored in tangible and non-transitory computer readable medium such as fixed Attorney Docket No.: Princeton - 103176 or removable media or memory, and / or stored within a memory within a computing device operating according to the instructions.

[0136] Referring now to FIG. 12, another embodiment of a system (1200) is shown. The system (1200) may include a first system (1210) for maintaining steam production in a power plant. The first system (1210) may include one or more processing units (1211) operably coupled to a memory (1212). a non-transitory computer-readable storage device (1213), a communications interface (1214), and one or more input / output devices (1215) (e.g., a display, a mouse, a keyboard, etc ). The processing unit(s) may be operably coupled to additional components as needed to perform the various tasks.

[0137] As used herein, the term “processing unit’' may refer to any CPU, GPU, core hardware thread, or other processing construct. As used herein, the term “thread” refers to any software or processing unit or arrangement thereof that is configured to support the concurrent execution of multiple operations.

[0138] The first system (1210) may be configured to operably communicate with one or more first remote processing units (1220) that may be used by one or more plant workers (1221) who would like to operate a power plant without the use of a duct burner. The one or more first remote processing units may include a control device, that may be, e.g., a computer that is installed in a control room of a power plant, and has a function to control, for example, fluid flow rate, pressure residence time, or a combination thereof. The one or more first remote processing units may be configured to control and coordinate operation of a combustion turbine, heat recovery steam generator, steam turbine, or thermal storage system.

[0139] The first system may be configured to operably communicate with one or more third remote processing units (1240). The third remote processing units may include, e.g., one or more databases or applications accessible via one or more application programming interfaces (APIs).

[0140] Various modifications may be made to the systems, methods, apparatus, mechanisms, techniques, and portions thereof described herein with respect to the various figures, such modifications being contemplated as being within the scope of the present disclosure. For example, while a specific order of steps or arrangement of functional elements is presented in the various embodiments described herein, various other orders / arrangements of steps or functional elements may be utilized within the context of the various embodiments. Further, while modifications to embodiments may be discussed individually, various embodiments may use multiple modifications contemporaneously or in sequence, compound modifications and the like. Attorney Docket No.: Princeton - 103176

[0141] Although various embodiments which incorporate the teachings of the present disclosure have been shown and described in detail herein, those skilled in the art can readily device many other varied embodiments that still incorporate these teachings. Thus, while the foregoing is directed to various embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof. As such, the appropriate scope of the present disclosure is to be determined according to the claims.

Claims

1. Attorney Docket No.: Princeton - 103176What is claimed is:

1. A method for steam production in a power plant using heat from a thermal storage medium in lieu of heat obtained from burning natural gas in duct burners and / or a combustion or fission process, comprising: heating up a thermal storage medium with electric heater elements or hot fluids with a heat exchanger; storing heat in the thermal storage medium for a period of time; generating a hot working fluid by transferring stored heat from the thermal storage medium to a working fluid that passes through the thermal storage medium, by means of at least one of convection, conduction, radiation, and transferring heat to a steam generation system directly using radiation; and using energy of the hot working fluid to generate additional electricity through a steam turbine.

2. The method of claim 1, wherein generating additional electricity includes directing the hot working fluid to a heat recovery' steam generator to generate steam or generating steam directly through the thermal storage medium.

3. The method of claim 2, further comprising using a steam regulator and distributor to control steam flows and steam quality for steam generated directly through the thermal storage medium.

4. The method of claim 1, wherein the power plant is at least one of a combined cycle gas turbine (CCGT) power plant, a coal fired power plant, or a nuclear fission power plant.

5. A system for maintaining steam production in a power plant, comprising: a thermal storage system including: a vessel for containing a thermal storage medium; a thermal storage medium heating subsystem configured to be operably coupled to a generator coupled to a substation coupled to a high-voltage transmission grid and / or a combustion turbine or steam turbine, the thermal storage medium heating subsystem including heater elements configured to receive electricity from the substation and / or generator to heat up the thermal storage medium and / or a heat exchanger configured to receive a hot fluid;Attorney Docket No.: Princeton - 103176 a working fluid input and a working fluid output, the working fluid input configured to receive a working fluid at a first temperature, the working fluid output configured to output the working fluid at a second temperature greater than the first temperature; and wherein the output from the thermal storage system is configured to be coupled to a heat recovery steam generator or a steam turbine.

6. The system of claim 5, wherein the working fluid is a liquid at a standard temperature and pressure.

7. The system of claim 5, wherein the working fluid is a vapor at standard temperature and pressure.

8. The system of claim 5, wherein the working fluid is either air, supercritical CO2, or water.

9. The system of claim 5. wherein the output from the thermal storage system is coupled to the steam turbine, and wherein the system further comprises a steam regulator and distributor to control steam flows and steam quality from the thermal storage system to the steam turbine.

10. The system of claim 5, further comprising: a combustion turbine operably coupled to a first electricity generator, the combustion turbine configured to receive a fuel from a fuel source; a heat recovery steam generator configured to receive exhaust gases or waste heat from the combustion turbine and generate steam; and a steam turbine operably coupled to a second electricity generator, the steam turbine configured to receive steam from the heat recovery steam generator.

11. The system of claim 5, further comprising thermal insulation around at least a portion of the thermal storage system.Attorney Docket No.: Princeton - 10317612. An integrated heat exchanger, comprising: a solid energy storage core containing a plurality of openings extending therethrough from a first outer surface to a second outer surface, the solid energy storage core composed of a thermal storage material; and piping disposed within the plurality of openings, the piping including an inlet and an outlet.

13. The integrated heat exchanger of claim 12, wherein the thermal storage material is composed of graphite, a graphite-based composite material, a cementitious composite material, or cement.

14. The integrated heat exchanger of claim 12, wherein the thermal storage material is composed of a thermal storage material other than graphite, a graphite-based composite material, a cementitious composite material, or cement.

15. The integrated heat exchanger of claim 12, wherein the piping forms a single flow channel from inlet to outlet.

16. The integrated heat exchanger of claim 12, wherein the piping forms a plurality of flow channels, each flow channel coupled to the inlet and outlet.

17. The integrated heat exchanger of claim 12, wherein the piping is directly bonded to the thermal storage material.

18. The integrated heat exchanger of claim 12, wherein within each flow channel, there is a gap between an outer surface of the piping and an inner surface of the thermal storage material forming each opening.

19. The integrated heat exchanger of claim 18, wherein the gap is filled with an intermediary heat transfer fluid.

20. The integrated heat exchanger of claim 19, wherein the intermediary heat transfer fluid comprises helium, a high thermal conductivity liquid, or a combination thereof.Attorney Docket No.: Princeton - 10317621. The integrated heat exchanger of claim 12, wherein the piping is composed of a high- temperature, oxidation-resistant metal, ceramic, or composite.

22. The integrated heat exchanger of claim 12, wherein the piping is composed of a stainless steel, an Inconel alloy, a Haynes alloy, niobium alloy, tungsten alloy, Alumina- Forming Austenitic Stainless Steels. a Ni-Cr alloy, or nickel aluminide.

23. The integrated heat exchanger of claim 12, wherein the piping is composed of a ferrous or non-ferrous metal.

24. The integrated heat exchanger of claim 12, wherein the piping is configured to be removable from the plurality of openings.

25. A heat exchanger system, comprising: at least one integrated heat exchanger of claim 12; and a means for heating the thermal storage material.

26. The heat exchanger system of claim 25, wherein the means for heating the thermal storage material includes joule heating elements disposed around the thermal storage material that heat the thermal storage material by radiation, conduction, or both.

27. The heat exchanger system of claim 25, wherein the thermal storage material is composed of an electrically conductive material, and the means for heating the thermal storage material includes resistive heating of the electrically conductive material.

28. The heat exchanger system of claim 25, wherein the means for heating the thermal storage material includes a heat transfer fluid configured to heat the thermal storage material by means of the integrated heat exchanger.

29. The heat exchanger system of claim 25. wherein the heat exchanger system is configured to transfer heat from the thermal storage material to each flow channel by direct conduction, convection through an intermediary heat transfer fluid, radiation, or a combination thereof.Attorney Docket No.: Princeton - 10317630. The heat exchanger system of claim 25, wherein the at least one integrated heat exchanger comprises a single integrated heat exchanger.

31. The heat exchanger system of claim 25, wherein the at least one integrated heat exchanger comprises a plurality of integrated heat exchangers arranged in series, parallel, or a combination thereof.

32. The heat exchanger system of claim 25, further comprising a fluid disposed within the piping.

33. The heat exchanger system of claim 32, wherein the fluid is liquid water at an input to the at least one integrated heat exchanger and steam at an elevated temperature at an output from the at least one integrated heat exchanger.

34. The heat exchanger system of claim 33, further comprising a controller configured to regulate fluid flow rate, pressure, residence time, or a combination thereof through the piping to provide steam at the output at a desired fluid pressure and temperature.

35. The heat exchanger system of claim 34, further comprising one or more sensors operably coupled to the controller, the one or more sensors configured to provide at least a fluid temperature and pressure at the output of the heat exchanger system.

36. The heat exchanger system of claim 33, further comprising at least one bypass loop operably coupled to the inlet and outlet of the at least one integrated heat exchanger.

37. A method for heat exchanger, comprising: heating a thermal storage medium; and transferring heat from the thermal storage medium to a fluid within piping that extends through openings within the thermal storage medium, heat being transferred to the fluid via direct conduction, convection through an intermediary heat transfer fluid, radiation, or a combination thereof.

38. The method of claim 37, further comprising providing the fluid to the piping at a supercritical inlet pressure.Attorney Docket No.: Princeton - 10317639. The method of claim 37, further comprising controlling fluid flow rate, pressure, residence time, or a combination thereof of the fluid within the piping to achieve a target output.

40. The method of claim 39, wherein the target output comprises steam with a fixed constant temperature and a fixed constant pressure, the fixed constant temperature is a temperature of 100°C-1000°C and the fixed constant pressure is a pressure of 1-200 bar.

41. The method of claim 39, wherein the target output comprises steam with varying temperatures and pressures, the temperatures being within 200°C-700°C and pressures being 1-200 bar.

42. A method for steam production in a power plant using heat from a hot working fluid in lieu of heat obtained from burning natural gas in duct burners and / or a combustion or fission process, comprising: providing an integrated heat exchanger of claim 12; heating up a thermal storage material with heater elements or hot fluids with the integrated heat exchanger; storing heat in the thermal storage material for a period of time; generating a hot working fluid by transferring stored heat from the thermal storage material to a working fluid that passes through the thermal storage material, by means of at least one of convection, conduction, radiation, and transferring heat to a steam generation system directly using radiation; and using heat of the hot working fluid to generate additional electricity' through a steam turbine.

43. The method of claim 42, wherein generating additional electricity7includes directing the hot working fluid to a heat recovery steam generator to generate steam or generating steam directly through the thermal storage material.

44. The method of claim 43. further comprising using a steam regulator and distributor to control steam flows and steam quality for steam generated directly through the thermal storage material.Attorney Docket No.: Princeton - 10317645. The method of claim 42. wherein the power plant is at least one of a combined cycle gas turbine (CCGT) power plant, a coal fired power plant, or a nuclear fission power plant.

46. A system for maintaining steam production using heat from a hot working fluid in lieu of heat obtained from burning natural gas in duct burners and / or a combustion or fission process, comprising: a thermal storage system including: a vessel for containing an integrated heat exchanger; an integrated heat exchanger of claim 12 configured to be operably coupled to a combustion turbine or generator coupled to the combustion turbine, the integrated heat exchanger configured to receive a hot fluid from the combustion turbine to heat up the thermal storage material; and wherein an output of the integrated heat exchanger is configured to be coupled to a heat recover}' steam generator or steam turbine.

47. The system of claim 46, wherein the hot fluid is a liquid at standard temperature and pressure.

48. The system of claim 46, wherein the hot fluid is a vapor at standard temperature and pressure.

49. The system of claim 46, wherein the hot fluid is air, supercritical CO2, or water.

50. The system of claim 46, wherein the output from the thermal storage system is coupled to the steam turbine, and wherein the system further comprises a steam regulator and distributor to control steam flows and steam quality from the thermal storage system to the steam turbine.

51. The system of claim 46, further comprising: a combustion turbine operably coupled to a first electricity generator, the combustion turbine configured to receive fuel from a fuel source; a heat recovery steam generator configured to receive exhaust gases or waste heat from the combustion turbine and generate steam; and a steam turbine operably coupled to a second electricity generator, the steam turbine configured to receive steam, from the heat recover steam generator.Attorney Docket No.: Princeton - 10317652. The system of claim 46, further comprising thermal insulation around at least a portion of the thermal storage system.

53. The system of claim 46, further comprising at least one sensor operably coupled to the outlet of the integrated heat exchanger.

54. The system of claim 53. wherein the at least one sensor is configured to measure a temperature of the hot fluid.

55. The system of claim 53. wherein the at least one sensor is configured to measure a pressure of the hot fluid.

56. The system of claim 46, further comprising anon-transitory computer-readable medium operably coupled to at least one processor.

57. The system of claim 56, wherein the at least one processor and non -transitory computer- readable medium are configured to receive measurements from a plurality of sensors.

58. The system of claim 57, wherein the at least one processor is configured to control temperature of the hot fluid according to the measurements.

59. The system of claim 57, wherein the at least one processor is configured to control pressure of the hot fluid according to the measurements.

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