heat engine

Abstract

A method for converting heat to mechanical work includes: supplying an inflow heat transfer fluid (HTF) at a first temperature to a mixing chamber; supplying an inflow compressed gas at a second temperature to the mixing chamber; allowing the gas and the HTF to mix to produce a gas-HTF mixture; allowing the HTF in the gas-HTF mixture to heat the gas and the gas in the gas-HTF mixture to undergo isothermal expansion; restricting a volume of the gas-HTF mixture, thereby increasing the pressure of the gas and accelerating the flow of the gas-HTF mixture; and ejecting the gas-HTF mixture through a nozzle, thereby converting the heat of the HTF to kinetic energy and using the kinetic energy to generate mechanical work. Related apparatus and methods are also described.

Description

[Technical Field]

[0001] Related Applications This application is a continuation-in-part of U.S. Provisional Patent Application No. 63 / 184,928, filed May 6, 2021, which is a continuation-in-part of U.S. Provisional Patent Application No. 63 / 074,485, filed September 4, 2020, the contents of all of which are incorporated by reference as if fully set forth herein in their entireties.

[0002] The present disclosure, in some embodiments thereof, relates to heat engines, and more particularly, but not exclusively, to systems and methods for operating heat engines using a mixture of gas and fluid. [Background technology]

[0003] Further background art includes: U.S. Patent No. 5,598,700 to Varshay et al. "Innovative Concepts for High-Speed ​​Underwater Propulsion," Alon Gany, International Journal of Energetic Materials and Chemical Propulsion, 17(2):83-109(2018), and Paper “Theoretical Performance Evaluation of a Marine Solid Propellant Water‐Breathing Ramjet Propulsor”, Nachum E. Eisen and Alon Gany, J. Mar. Sci. Eng. 2020, 8, 8; doi:10.3390 / jmse8010008.

[0004] The disclosures of all references cited above and throughout this specification, as well as all references cited within those references, are hereby incorporated by reference. Summary of the Invention [Means for solving the problem]

[0005] The present disclosure, in some embodiments thereof, relates to external heat engines, and more particularly, but not exclusively, to systems and methods for operating external heat engines using a mixture of gas and fluid.

[0006] According to an aspect of some embodiments of the present disclosure, there is provided a method for converting heat to mechanical work, the method including: supplying an inflow heat transfer fluid (HTF) at a first temperature to a mixing chamber; supplying an inflow compressed gas at a second temperature to the mixing chamber; allowing the gas and the HTF to mix to produce a gas-HTF mixture; allowing the HTF in the gas-HTF mixture to heat the gas and the gas in the gas-HTF mixture to expand isothermally; restricting a volume of the gas-HTF mixture, thereby increasing the pressure of the gas and accelerating the flow of the gas-HTF mixture; and ejecting the gas-HTF mixture from a nozzle, thereby converting the heat of the HTF to kinetic energy; and using the kinetic energy to generate mechanical work.

[0007] According to some embodiments of the present disclosure, the mechanical work is used to drive an electrical generator.

[0008] According to some embodiments of the present disclosure, mechanical work is used to drive a compressor to compress the incoming compressed gas.

[0009] According to some embodiments of the present disclosure, the first temperature of the inlet HTF is greater than 90 degrees Celsius.

[0010] According to some embodiments of the present disclosure, the second temperature of the input gas is lower than the first temperature.

[0011] According to some embodiments of the present disclosure, providing the inlet gas, providing the inlet HTF, and allowing the mixture of the gas and HTF to flow through the nozzles includes providing the inlet gas to a plurality of mixing chambers, providing the inlet HTF to a plurality of mixing chambers, allowing the mixture of the gas and HTF to flow through a plurality of nozzles, and using motion of the plurality of nozzles to generate work.

[0012] According to some embodiments of the present disclosure, the gas is quasi-isochorically heated by the HTF.

[0013] According to some embodiments of the present disclosure, the gas is isochorically heated by the HTF.

[0014] According to some embodiments of the present disclosure, the generation of kinetic energy is controlled by controlling a parameter selected from the group consisting of the pressure of the incoming compressed gas, the flow rate of the incoming gas, the flow rate of the incoming HTF, the size of the nozzle, and the shape of the nozzle.

[0015] According to an aspect of some embodiments of the present disclosure, there is provided an apparatus for generating mechanical work, the apparatus including a heat engine having a heat transfer fluid (HTF) input port for receiving a HTF, a gas injection port for injecting a gas into the HTF, a chamber for mixing the gas and the HTF to generate a mixture of the gas and the HTF, a nozzle for ejecting the mixture of the gas and the HTF, and a rotor, wherein the heat engine includes one or more nozzles, and when the mixture of the gas and the HTF is ejected through the one or more nozzles, the rotor rotates in reaction to the ejection of the mixture of the gas and the HTF, thereby generating mechanical work.

[0016] According to some embodiments of the present disclosure, an apparatus includes a plurality of heat engines and a plurality of nozzles.

[0017] According to some embodiments of the present disclosure, the rotor includes a plurality of arms.

[0018] According to some embodiments of the present disclosure, the heat engine is designed to withstand HTF temperatures in excess of 200 degrees Celsius.

[0019] According to some embodiments of the present disclosure, the heat engine is designed to withstand HTF, including molten salts.

[0020] According to some embodiments of the present disclosure, the heat engine is designed to prevent cavitation of the gas and HTF mixture.

[0021] According to an aspect of some embodiments of the present disclosure, there is provided a method for operating a heat engine, the method including supplying a heat transfer fluid (HTF) to the heat engine, supplying a gas to the heat engine, accelerating the HTF in the heat engine by allowing an isothermal expansion of the gas in a mixture of the gas and the HTF, and generating work using the accelerated HTF.

[0022] According to some embodiments of the present disclosure, the isothermal expansion is a quasi-isothermal expansion.

[0023] According to some embodiments of the present disclosure, isochoric heating of the gas is induced before allowing for isothermal or quasi-isothermal expansion.

[0024] According to some embodiments of the present disclosure, the heat engine includes a nozzle.

[0025] According to some embodiments of the present disclosure, delivering HTF includes delivering HTF at a temperature greater than 50 degrees Celsius.

[0026] According to some embodiments of the present disclosure, supplying HTF includes supplying HTF at ambient temperature.

[0027] According to some embodiments of the present disclosure, mixing the gas and the HTF includes providing the gas at a pressure greater than ambient pressure.

[0028] According to some embodiments of the present disclosure, mixing the gas and the HTF includes providing the gas at a temperature above ambient temperature.

[0029] According to some embodiments of the present disclosure, mixing the gas and the HTF includes providing the gas at ambient temperature.

[0030] According to some embodiments of the present disclosure, mixing the gas and the HTF includes providing the gas at a temperature above ambient temperature.

[0031] According to some embodiments of the present disclosure, the work generated is used to pressurize a gas.

[0032] According to some embodiments of the present disclosure, hot gases exiting the heat engine are used to heat the HTF.

[0033] According to some embodiments of the present disclosure, the hot gases exiting the heat engine are used to drive a further heat engine.

[0034] According to an aspect of some embodiments of the present disclosure, there is provided a heat engine including an input for a heat transfer fluid (HTF), a gas injector for injecting gas into the HTF, a zone for accelerating the HTF within the heat engine by isothermal expansion of gas in the mixture of the gas and the HTF, and an output of the mixture of the gas and the HTF.

[0035] According to some embodiments of the present disclosure, the system includes a zone for isochoric heating of the gas in the mixture of gas and HTF.

[0036] According to some embodiments of the present disclosure, the heat engine includes progressively narrower sections of the heat engine for isothermal expansion of a gas.

[0037] According to some embodiments of the present disclosure, the heat engine includes a section of the heat engine for isochoric heating of a gas.

[0038] According to some embodiments of the present disclosure, the heat engine includes a nozzle through which the HTF flows.

[0039] According to some embodiments of the present disclosure, an engine is mechanically connected to provide power to supply pressurized gas to the gas injector.

[0040] According to some embodiments of the present disclosure, the engine is connected to generate electricity to power the pressurized gas to supply the pressurized gas to the gas injector.

[0041] According to one aspect of some embodiments of the present disclosure, there is provided a method for generating rotational force, the method comprising: attaching a heat engine according to any one of claims 30 to 35 to at least one rotor arm; and supplying a fluid and a pressurized gas to the heat engine to rotate the rotor arm.

[0042] According to some embodiments of the present disclosure, supplying a fluid includes supplying a heated fluid at a temperature above ambient temperature.

[0043] According to some embodiments of the present disclosure, supplying the pressurized gas includes supplying the pressurized gas and injecting the pressurized gas into the fluid at a radial distance from the axis of rotation of the rotor arm that is less than the radial distance of the nozzle.

[0044] According to some embodiments of the present disclosure, supplying pressurized gas includes supplying pressurized gas and injecting the pressurized gas into the fluid at a location prior to the fluid input to the nozzle.

[0045] According to some embodiments of the present disclosure, the location at which pressurized gas is injected into the fluid is selected so that the flow of fluid flowing outward along the arm does not interfere with drawing HTF from the HTF source into the arm.

[0046] According to some embodiments of the present disclosure, the location at which the pressurized gas is injected into the fluid is selected so that the HTF flowing outward along the arm drags the gas towards the nozzle.

[0047] According to an aspect of some embodiments of the present disclosure, there is provided a method of operating a heat engine, the method including: supplying gas at a first temperature and a first pressure to a heating chamber; isochorically heating the gas in the heating chamber to a second temperature higher than the first temperature by heat transfer from a heat transfer fluid (HTF), thereby raising the pressure of the gas to the second pressure higher than the first pressure; supplying the heated and pressurized gas to a pressure chamber containing the HTF; and using the pressure to produce a flow of HTF to operate the engine.

[0048] According to some embodiments of the present disclosure, this involves mixing the HTF with a heated and pressurized gas in a pressure chamber.

[0049] According to some embodiments of the present disclosure, the method includes collecting HTF exiting the engine and returning the collected HTF to a pressure chamber.

[0050] According to some embodiments of the present disclosure, the method includes heating the HTF by using a heat source selected from the group consisting of solar panels, concentrated solar receivers, geothermal sources, electric heaters, exothermic chemical reactions, mechanical friction, and waste heat.

[0051] According to some embodiments of the present disclosure, the engine provides energy to compress gas at ambient pressure at a first pressure in the gas chamber, and supplying gas at the first temperature and first pressure to the heating chamber includes supplying from an HTF chamber.

[0052] According to some embodiments of the present disclosure, the HTF comprises a fluid selected from the group consisting of water, oil, molten salt, and molten metal.

[0053] According to an aspect of some embodiments of the present disclosure, there is provided a method for converting heat to mechanical work, the method including: supplying an inflow heat transfer fluid (HTF) to a mixing chamber; supplying an inflow compressed gas to the mixing chamber; allowing the gas and the HTF to mix to produce a gas-HTF mixture; allowing isothermal expansion of the gas in the gas-HTF mixture, thereby reducing the pressure of the gas and accelerating the flow of the gas-HTF mixture; ejecting the gas-HTF mixture from a nozzle, thereby converting the heat of the HTF to kinetic energy; and using the kinetic energy to generate electricity.

[0054] According to an aspect of some embodiments of the present disclosure, there is provided a method of continuous isothermal compression including: supplying a heat transfer fluid (HTF) to an HTF input of an HTF flow pipe; rotating the pipe, thereby creating centrifugal forces in the HTF to flow from the input to a second, more distal radial location; supplying a gas to a gas input of the pipe, thereby mixing the gas and the HTF, and compressing the gas as it flows along the pipe due to the increased centrifugal forces created by the rotation of the pipe; and transferring heat of compression to the HTF, thereby allowing the gas to maintain its temperature during compression.

[0055] According to an aspect of some embodiments of the present disclosure, there is provided a system including: a heating chamber containing a gas at a first temperature and a first pressure; a heater for heating the gas, thereby increasing the temperature and pressure of the gas; a pressure chamber configured to receive the heated and pressurized gas and containing a heat transfer fluid (HTF), the pressure chamber including a mixing element for mixing the HTF with the gas and an opening for exiting the HTF at an accelerated rate involving isothermal expansion of the gas; and an engine configured to receive the accelerated HTF and generate work.

[0056] According to an aspect of some embodiments of the present disclosure, there is provided a method for operating a heat engine, the method including supplying a heat transfer fluid (HTF) to an input section of the heat engine, mixing a gas and the HTF in an injection section of the heat engine downstream of the input section, accelerating the HTF in the heat engine by allowing an isothermal expansion of the gas in the gas-HTF mixture, and generating work using the accelerated HTF.

[0057] According to some embodiments of the present disclosure, isochoric heating of the gas is induced before allowing isothermal expansion.

[0058] According to some embodiments of the present disclosure, isothermal compression of the gas is induced before allowing isochoric heating of the gas.

[0059] According to some embodiments of the present disclosure, the heat engine includes a nozzle.

[0060] According to some embodiments of the present disclosure, delivering HTF includes delivering HTF at a temperature above 0 degrees Celsius.

[0061] According to some embodiments of the present disclosure, delivering HTF includes delivering HTF at a temperature greater than 50 degrees Celsius.

[0062] According to some embodiments of the present disclosure, providing HTF includes providing HTF at a temperature greater than 250 degrees Celsius.

[0063] According to some embodiments of the present disclosure, mixing the gas and the HTF includes providing the gas at a pressure greater than ambient pressure.

[0064] According to some embodiments of the present disclosure, mixing the gas and the HTF includes providing the gas at a temperature above ambient temperature.

[0065] According to some embodiments of the present disclosure, the work generated is used to pressurize a gas.

[0066] According to some embodiments of the present disclosure, the work generated includes the production of electricity.

[0067] According to some embodiments of the present disclosure, the work generated includes the production of mechanical work.

[0068] According to an aspect of some embodiments of the present disclosure, there is provided a heat engine including an input for a heat transfer fluid (HTF), a gas injector for injecting gas into the HTF, a zone for accelerating the HTF within the heat engine by isothermal expansion of gas in the mixture of the gas and the HTF, and an output of the mixture of the gas and the HTF.

[0069] According to some embodiments of the present disclosure, the system includes a zone for isochoric heating of the gas in the mixture of gas and HTF.

[0070] According to some embodiments of the present disclosure, the heat engine includes progressively narrower sections of the heat engine for isothermal expansion of a gas.

[0071] According to some embodiments of the present disclosure, the heat engine includes a section of the heat engine for isochoric heating of a gas.

[0072] According to some embodiments of the present disclosure, the heat engine includes a nozzle through which the HTF flows.

[0073] According to some embodiments of the present disclosure, a source of heated HTF is included.

[0074] According to some embodiments of the present disclosure, a source of pressurized gas is included.

[0075] According to some embodiments of the present disclosure, an engine is mechanically connected to provide power to supply pressurized gas to the gas injector.

[0076] In accordance with an aspect of some embodiments of the present disclosure, there is provided a method of generating a rotational force, the method including attaching a nozzle to at least one rotor arm and supplying a fluid and pressurized gas to the nozzle to rotate the rotor arm.

[0077] According to some embodiments of the present disclosure, supplying a heated fluid includes supplying a heated fluid at a temperature above ambient temperature.

[0078] According to some embodiments of the present disclosure, supplying the pressurized gas includes supplying the pressurized gas and injecting the pressurized gas into the fluid at a radial distance from the axis of rotation of the rotor arm that is less than the radial distance of the nozzle.

[0079] According to some embodiments of the present disclosure, supplying pressurized gas includes supplying pressurized gas and injecting the pressurized gas into the fluid at a location prior to the location of the fluid input to the nozzle.

[0080] According to some embodiments of the present disclosure, the location at which pressurized gas is injected into the fluid is selected so that the flow of fluid flowing outward along the arm does not interfere with drawing HTF from the HTF source into the arm.

[0081] According to some embodiments of the present disclosure, the location at which the pressurized gas is injected into the fluid is selected so that the HTF flowing outward along the arm drags the gas towards the nozzle.

[0082] According to an aspect of some embodiments of the present disclosure, there is provided a method of operating a heat engine, the method including: supplying gas at a first temperature and a first pressure to a heating chamber; isochorically heating the gas in the heating chamber to a second temperature higher than the first temperature by heat transfer from a heat transfer fluid (HTF), thereby raising the pressure of the gas to the second pressure higher than the first pressure; supplying the heated and pressurized gas to a pressure chamber containing the HTF; and using the pressure to produce a flow of HTF to operate the engine.

[0083] According to some embodiments of the present disclosure, this involves mixing the HTF with a heated and pressurized gas in a pressure chamber.

[0084] According to some embodiments of the present disclosure, the method includes storing the HTF and the heated and pressurized gas in a pressure chamber.

[0085] According to some embodiments of the present disclosure, the engine includes a turbine.

[0086] According to some embodiments of the present disclosure, the method includes collecting HTF exiting the engine and returning the collected HTF to a pressure chamber.

[0087] According to some embodiments of the present disclosure, the method includes heating the HTF by using a heat source selected from the group consisting of solar panels, concentrated solar receivers, geothermal sources, electric heaters, exothermic chemical reactions, mechanical friction, and waste heat.

[0088] According to some embodiments of the present disclosure, the engine provides energy to compress gas at ambient pressure in the heating chamber at a first pressure.

[0089] According to some embodiments of the present disclosure, the engine provides energy to compress gas at ambient pressure at a first pressure in the gas chamber, and supplying gas at the first temperature and first pressure to the heating chamber includes supplying from an HTF chamber.

[0090] According to some embodiments of the present disclosure, the gas is air.

[0091] According to some embodiments of the present disclosure, the gas is nitrogen.

[0092] According to some embodiments of the present disclosure, the HTF comprises a fluid selected from the group consisting of water, oil, molten salt, and molten metal.

[0093] According to some embodiments of the present disclosure, the second temperature is greater than 370 Kelvin.

[0094] According to an aspect of some embodiments of the present disclosure, there is provided a system including: a heating chamber containing a gas at a first temperature and a first pressure; a heater for heating the gas, thereby increasing the temperature and pressure of the gas; a pressure chamber configured to receive the heated and pressurized gas and containing a heat transfer fluid (HTF), the pressure chamber including a mixing element for mixing the HTF with the gas and an opening for exiting the HTF at an accelerated rate involving isothermal expansion of the gas; and an engine configured to receive the accelerated HTF and generate work.

[0095] According to some embodiments of the present disclosure, the system further includes a mixer for mixing the pressurized gas and the HTF within the pressure chamber.

[0096] According to some embodiments of the present disclosure, the engine further includes an HTF chamber for collecting HTF exiting the engine.

[0097] According to some embodiments of the present disclosure, the method further includes a pump for delivering the collected HTF to the pressure chamber.

[0098] According to some embodiments of the present disclosure, the method further includes a heat source for heating the HTF pumped from the HTF chamber to the pressure chamber.

[0099] According to some embodiments of the present disclosure, the heat source comprises a heat source selected from the group consisting of a solar panel, a concentrated solar receiver, an electric heater, an exothermic chemical reaction, mechanical friction, geothermal heat, and waste heat.

[0100] According to some embodiments of the present disclosure, the engine has a turbine.

[0101] According to some embodiments of the present disclosure, the engine generates electricity.

[0102] According to some embodiments of the present disclosure, the engine generates mechanical work.

[0103] According to some embodiments of the present disclosure, the engine compresses a gas.

[0104] According to some embodiments of the present disclosure, the heating chamber includes an engine for providing electricity connected to a pump for pressurizing the gas in the heating chamber.

[0105] According to some embodiments of the present disclosure, the heating chamber further includes a gas chamber for storing the gas at the first temperature and the first pressure prior to supplying the gas at the first temperature and the first pressure to the heating chamber.

[0106] According to some embodiments of the present disclosure, the engine provides electricity by connecting to a pump for pressurizing gas in the gas chamber.

[0107] According to some embodiments of the present disclosure, the engine is mechanically connected to drive a pump for pressurizing gas in the gas chamber.

[0108] According to some embodiments of the present disclosure, the device includes an additional chamber connected to the gas chamber for storing pressurized gas from the gas chamber.

[0109] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, exemplary methods and / or materials are described below. In case of conflict, the patent specification, including definitions, will control. Furthermore, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

[0110] Several embodiments of the present disclosure are herein described, by way of example only, with reference to the accompanying drawings. With particular reference now to the drawings in detail, it is emphasized that the details shown are by way of example and for the purpose of illustrative discussion of embodiments of the present disclosure. In this regard, the description using the drawings will make apparent to those skilled in the art how embodiments of the present disclosure may be practiced. [Brief explanation of the drawings]

[0111] [Figure 1A] FIG. 1 illustrates a simplified flowchart of a method according to an exemplary embodiment. [Figure 1B] FIG. 1 illustrates a simplified flowchart of a method according to an exemplary embodiment. [Figure 1C] FIG. 1 illustrates a simplified block diagram of a heat engine in accordance with an illustrative embodiment; [Figure 1D] FIG. 1 illustrates a simplified block diagram of a heat engine in accordance with an illustrative embodiment; [Figure 1E] 1 is a simplified diagram of an exemplary embodiment; [Figure 2] 1A and 1B are PV and TS diagrams of an exemplary embodiment; [Figure 3] 1 is a simplified diagram of an exemplary embodiment; [Figure 4A] 1 is a simplified diagram of a system for converting heat to work by creating a vacuum in accordance with an illustrative embodiment; [Figure 4B] 1 is a simplified diagram of a heat engine for use in an energy generation system according to an illustrative embodiment; [Figure 4C] 1 is a simplified diagram of the use of a chamber to mix a heated fluid and a gas according to an exemplary embodiment. [Figure 4D] FIG. 1 is a simplified diagram of the use of two chambers according to an exemplary embodiment. [Figure 4E] 1 is a simplified diagram of the use of a chamber to mix a heated fluid and a gas according to an exemplary embodiment. [Figure 4F] FIG. 1 is a simplified diagram of the use of two chambers according to an exemplary embodiment. [Figure 5]FIG. 1 is a simplified diagram of the use of a nozzle as a heat engine according to an illustrative embodiment; [Figure 6] 1 is a simplified diagram of an exemplary embodiment heat engine for use in an energy generation setting according to an exemplary embodiment. [Figures 7A-7D] 1 is a simplified diagram of a heat engine configured like a jet engine in accordance with an illustrative embodiment; [Figure 8A] 1 is a simplified diagram of an apparatus configured like multiple jet engines in accordance with an illustrative embodiment; [Figure 8B] 1 is a simplified diagram of a reaction device in accordance with an illustrative embodiment; [Figure 8C] 1 is a simplified diagram of a reaction device in accordance with an illustrative embodiment; [Figure 9] 1 is a simplified diagram of a combined reaction and impulse heat engine turbine in accordance with an illustrative embodiment; FIG. [Figure 10A] 1 is a simplified diagram of an apparatus for continuous isothermal compression of a gas according to an illustrative embodiment; [Figure 10B] 1 is a simplified diagram of an apparatus for continuous isothermal compression of a gas according to an illustrative embodiment; [Figure 11] FIG. 1 is a simplified diagram of an energy generation system using a combination heat engine and compressed air generator in accordance with an illustrative embodiment. [Figure 12A] 1 is a photograph of a water jet without added air or gas according to an example embodiment; [Figure 12B] 10 is a photograph of a water jet with the addition of air or gas according to an example embodiment; [Figure 13] FIG. 1 illustrates a simplified flowchart of a method according to an exemplary embodiment. [Figure 14] 1 is a simplified diagram of a system according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0112] The present disclosure, in some embodiments thereof, relates to heat engines, and more particularly, but not exclusively, to systems and methods for operating heat engines using a mixture of gas and fluid.

[0113] overview One aspect of some embodiments involves mixing two materials: a first material with a high heat capacity and a second material with one or more properties that can be used to convert the thermal energy of the high heat capacity material into mechanical energy.

[0114] In some embodiments, the property used to convert thermal energy of the high heat capacity material into mechanical energy is the compressibility of the second material.

[0115] A non-limiting example of two such materials is a liquid as the first material and a gas as the second material. Liquids typically have a higher heat capacity than gases. Gases are compressible, while liquids typically are not.

[0116] When a liquid and a gas are mixed, there may be a heat exchange between the liquid and the gas, especially if the gas is mixed into the liquid in the form of multiple bubbles.

[0117] As a non-limiting example, when a liquid is hotter than a gas, the gas heats up. When heating occurs in a sealed chamber, the gas heats up to the temperature of the liquid, and the temperature of the liquid changes only slightly because the gas has a lower heat capacity than the liquid. As the gas heats up, the pressure of the gas increases. The gas-liquid mixture now has usable mechanical energy.

[0118] In some embodiments, it does not matter if the liquid or fluid is initially hotter than the gas. The compressed air may be injected into a liquid or fluid that is at the same temperature as the compressed air. The liquid or fluid maintains the gas-fluid mixture at approximately the same temperature as the initial temperature of the fluid, even during the expansion of the gas, due to the greater heat capacity of the fluid. The fluid prevents the gas from cooling due to the expansion.

[0119] In some embodiments, the chamber containing the gas and liquid mixture is a sealed chamber, hi some embodiments, the sealed chamber is optionally opened when use of mechanical energy is desired.

[0120] In some embodiments, the chamber can have an opening, and gas can be continuously supplied to the chamber through one or more gas inlets, liquid can be continuously supplied to the chamber through one or more liquid inlets, and the gas and liquid mixture can be continuously ejected through one or more outlets or nozzles.

[0121] In some embodiments, the property of the first material is a high heat capacity, ie, a higher heat capacity than the second material.

[0122] In some embodiments, a property of the second material is that it is compressible.

[0123] In some embodiments, the property of the second material is a low heat capacity, ie, a lower heat capacity than the first material.

[0124] In some embodiments, the property of the first material is incompressibility or very low compressibility.

[0125] In some embodiments, a property of the second material is that it does not dissolve in the first material.

[0126] In some embodiments, the property of the second material is that it is less soluble in the first material, e.g., less than 10 percent of the second material can dissolve in the first material under operating conditions, such as the temperature and pressure, of the heat engine.

[0127] One aspect of some embodiments relates to mixing a fluid and a gas in an external heat engine, where the gas provides a compressible and / or expandable component in the gas-fluid mixture and the fluid provides a component with a much higher heat capacity than the gas.

[0128] In some embodiments, the fluid is at a higher temperature than the gas and the fluid heats the gas.

[0129] In some embodiments, the volume is kept constant or nearly constant, and thus the pressure increases as the fluid heats the gas.

[0130] In some embodiments, the temperature is held constant or nearly constant, so that the fluid heats the gas, causing it to expand and accelerate the flow of the gas-fluid mixture.

[0131] In some embodiments, a mixture of gas and fluid is compressed, and the pressure increases substantially isothermally because the compression of the gas does not provide enough heat to substantially heat the fluid.

[0132] An aspect of some embodiments relates to mixing a fluid and a gas in a heat engine, accelerating the fluid by isothermal expansion of the gas, and using the accelerated fluid to generate work.

[0133] The various figures of this application illustrate various aspects as follows:

[0134] 1A-1D illustrate a method and block diagram of a heat engine according to an exemplary embodiment, and FIG. 2 illustrates the method using graphs commonly used to describe thermodynamic systems.

[0135] 1E, 3, and 4A-4F illustrate the generation of energy using the process of one embodiment, optionally in conjunction with an energy storage system.

[0136] 5 and 6 illustrate the use of heat engine embodiments to generate energy, and optionally in conjunction with an energy storage system.

[0137] 7A-7D, 8A-8C, and 9 illustrate the use of heat engine embodiments to generate energy.

[0138] 10A and 10B illustrate the use of one or more rotating arms to continuously isothermally or near-isothermally compress a gas, which can optionally be used as a source of compressed gas for a variety of applications, including one or more of the heat engines and processes for producing energy described in the previous figures.

[0139] FIG. 11 illustrates that a compressor such as that illustrated in FIGS. 10A and 10B and a heat engine such as that illustrated in FIGS. 7A-7D, 8A-8C, and 9 work together to generate energy.

[0140] Many engines work by compressing a gas, i.e., increasing its pressure, and then heating it, i.e., increasing its pressure even more. Compression and heating increase the energy content of the gas. Such engines then use the concentrated energy to produce work by expanding the heated, compressed gas.

[0141] However, the heat capacity of gas is not as great as that of liquid.

[0142] Furthermore, as gas expands it cools and loses energy.

[0143] The term "air" in all grammatical forms is used interchangeably with the term "gas" and its corresponding grammatical forms throughout this specification and claims.

[0144] The use of "example" and "for example" in all grammatical forms is used interchangeably throughout this specification and claims with the use of "non-limiting example" and its corresponding grammatical forms.

[0145] In some embodiments, the heat engines described in Figures 7A-7D, 8A-8C, 9, and 14 are optionally operated continuously and supplied with compressed air from a source and / or chamber such as those described with reference to Figures 1E, 3, 4A-4F, 5, and 6. This is in contrast to systems that fill a chamber with compressed air and then shut down and refill the chamber from the source once the pressure in the chamber is depleted.

[0146] In some embodiments, the processes described herein are used when gases are used in conjunction with liquids, potentially offering the advantage that the gas expands nearly isothermally.

[0147] In some embodiments, the processes described herein are used when gases are used in conjunction with fluids, in the sense that fluids, as a non-limiting example of a liquid, expand less than gases, potentially offering the advantage that gases expand nearly isothermally.

[0148] The term isothermal in all grammatical forms is used in this specification and claims to mean that the temperature drop of a gas-fluid mixture is much less than the temperature drop without the temperature stabilizing effect of the fluid.

[0149] Note that without the temperature stabilizing effect of the fluid, the expansion of the gas would be adiabatic or isentropic.

[0150] In some embodiments, the gas is heated isochorically.

[0151] An isochoric process, also called a constant volume process, isochoric process, or isometric process, is a thermodynamic process in which the volume of a closed system undergoing such a process remains constant.

[0152] When a gas is heated isovolumically, the pressure increases with heating because the gas does not expand. Note that as the gas expands, some temperature drop or loss of heat occurs.

[0153] In some embodiments, heat engines are described herein as using isothermal expansion to capture more work from the expansion of a gas.

[0154] In some embodiments, isochoric heating is described herein as having more work in heating a gas than a non-isochoric process.

[0155] In some embodiments, isochoric heating is used to heat the gas and isothermal expansion is used to generate work.

[0156] In some embodiments, a mixture of gas and fluid is used to generate work, potentially benefiting from the advantages of the gas process described above, and imparting kinetic energy to the fluid, which may suitably power some types of engines, such as turbines, which use the kinetic energy of the gas or liquid to cause rotation.

[0157] A mixture of fluid and gas may be denser than gas alone and may be able to impart more moment to the turbine blades.

[0158] One aspect of some embodiments relates to heat engines that generate kinetic energy, potentially benefiting from the above advantages of gas processes.

[0159] In some embodiments, the kinetic energy is used to rotate and power an electrical generator.

[0160] In some embodiments, kinetic energy is used to rotate and power mechanical devices.

[0161] In some embodiments, kinetic energy is used to feed back into the heat engine by, by way of example and not limitation, the following:

[0162] Rotating a shaft used to force pressurized gas into an engine. In addition to the energy to pressurize the gas, the thermal energy added by the fluid can provide excess energy compared to the energy used to pressurize the gas.

[0163] Providing electricity to operate a pump to supply pressurized gas to the engine. In addition to the energy to pressurize the gas, the thermal energy added by the fluid can provide excess energy compared to the energy used to pressurize the gas.

[0164] An aspect of some embodiments relates to selecting and controlling the size of fluid droplets in a hot fluid and gas mixture within an engine to maintain the fluid heating the gas as the mixture passes through the engine.

[0165] In some embodiments, the size of the fluid droplets is controlled by determining the diameter of the holes through which the hot fluid is injected into the engine. In some embodiments, the selected hole diameter optionally takes into account the surface tension of the fluid at the desired temperature to produce droplets of the desired size.

[0166] An aspect of some embodiments relates to using heat from sources such as solar energy and / or waste heat and / or geothermal heat to operate a heat engine.

[0167] The above improvements for generating work from compressed and / or heated gas mixed with a fluid are suitable for using heat from a variety of sources, including waste heat from industrial processes and from solar energy devices such as concentrated solar energy devices and thermal solar panels.

[0168] An aspect of some embodiments relates to storing energy in the form of compressed gas or heat, and releasing the stored energy in a manner that potentially benefits from the above advantages of gas processes.

[0169] In some embodiments, the stored energy is released in a more efficient manner than previously possible.

[0170] Make work output continuous

[0171] It should be noted that chambers for containing fluids and gases are described herein with reference to various embodiments. The chambers typically have valves at their openings that are typically operated to open to allow fluid or gas or compressed gas to enter and close to allow a process to occur within the chamber without the fluid or gas leaving the chamber during the process.

[0172] For example, some chambers undergo a process described as isochoric heating. Isochoric or constant volume heating occurs when the chamber is closed so that no fluid or gas can leave the chamber, thereby keeping the volume constant.

[0173] It should be noted that the chambers described herein may be closed at some stages of the process and open at other stages. In some embodiments, to generate energy without the chambers being shut down to complete stages of the process, two or more chambers may be used to perform the same process, such that one chamber may be closed and not providing fluids and gases to perform work while another chamber is open and providing fluids and gases to perform work, resulting in a greater continuous output of work.

[0174] Engine type

[0175] The expansion of the gas in the fluid-gas mixture obtained by the methods described herein can power a variety of engines, all of which are intended to be included in the variations of the embodiments described herein, including, as some non-limiting examples, turbines, Kaplan design turbines, Pelton wheels, hydroelectric turbines, high temperature thermal oil turbines, ramjet engines, and jet engines.

[0176] heat source

[0177] A variety of heat sources can supply heat to fluids and gases using the methods described herein, and all such heat sources are intended to be included in the embodiment variations described herein, including, as some non-limiting examples, solar thermal, concentrated solar thermal, geothermal, waste heat from industrial processes, and heat from fossil fuels.

[0178] For example, we are not aware of any highly efficient engines with efficiencies above 33% for use in the solar power sector, e.g., at temperatures below 850 K and with capacities below 20 MW. Efficient heat engines, such as steam turbines, exist, but their capacities exceed 20 MW, requiring large energy sources or solar power plants and significant investments. Small steam turbines (<1 MW) typically have efficiencies below 20%.

[0179] Small, efficient engines could enable the use of distributed concentrated solar power, potentially reducing costs to less than 3¢ / kWh through economies of scale, similar to solar power generation, paving the way for 50% solar energy in the U.S. by 2050, compared to the current 10% solar energy, according to the National Renewable Energy Laboratory's (NREL) SunShot initiative.

[0180] Current small heat engines, such as Stirling engines, steam turbine engines, and gas turbines, are typically inefficient at 850K (less than 25% efficiency) and are typically expensive.

[0181] There are no known cost-effective engines for small capacities, such as less than 3 MW, at costs below $750 / kW.

[0182] A potential advantage of heat engines according to some embodiments described herein is that they may be more cost-effective than existing engines, at least up to a capacity of 15 MW.

[0183] A potential advantage of heat engines according to some embodiments described herein is that the use of fluids in addition to gases in the engine may reduce the size of the engine by up to three orders of magnitude.

[0184] In some solar energy systems, solar energy is converted into heat at a typical temperature of about 850 K, a low energy density compared to that of fossil fuels. Known heat engines typically operate with gases, which perform two functions: 1) performing the thermodynamic work of expansion and compression, and 2) transporting energy to the engine. Because gases have a relatively low heat capacity per volume, expansion of the gas in the engine is accompanied by a decrease in temperature. This contrasts with Carnot's description of an ideal engine, in which gas expansion occurs isothermally. Deviations from this ideal Carnot engine lead to a decrease in efficiency.

[0185] An aspect of some embodiments relates to a heat engine in which a heat transfer fluid supplies heat to a gas inside the engine during thermodynamic expansion and compression, resulting in isothermal or near isothermal expansion and compression and improved efficiency.

[0186] The term Carnot engine describes the theoretically most efficient work that can be done by a pump and turbine at constant temperature by isothermal compression and isothermal expansion.

[0187] Reference is now made to FIG. 1A, which illustrates a simplified flowchart of a method according to an exemplary embodiment.

[0188] FIG. 1A is intended to illustrate a thermal process that can extract more work from a compressed gas than would be extracted if the expansion of the gas were not isothermal.

[0189] The method illustrated by FIG. 1A includes: supplying a fluid (140); supplying gas (141); Combining gases and fluids (143); Allowing for isothermal expansion of gases and fluids (147), and This generates work (148). Includes.

[0190] In some embodiments, the method includes isochoric heating of the gas prior to the isothermal expansion (147).

[0191] Reference is now made to FIG. 1B, which illustrates a simplified flowchart of a method according to an exemplary embodiment.

[0192] FIG. 1B is intended to illustrate a thermal process that can extract more work from a compressed gas than would be extracted if the heating of the gas were not isochoric.

[0193] FIG. 1B also shows an optional stage of isothermal expansion that may extract more work from the compressed gas than would be extracted if the expansion were not isothermal.

[0194] The method illustrated by FIG. supplying a hot fluid (160); supplying gas (161); Combining gases and fluids (163); isochoric heating (165); Allowing the gas to expand (167), and This generates work (168). Includes.

[0195] In some embodiments, allowing the gas to expand (167) includes allowing the gas to expand isothermally.

[0196] Reference is now made to Figure 1C, which is a simplified block diagram of a heat engine in accordance with an illustrative embodiment.

[0197] FIG. 1C is intended to show a general heat engine in which pressurized gas and fluid are combined to produce work.

[0198] In the heat engine of FIG. 1C, pressurized gas 150 and fluid 151 are combined in combiner 152 .

[0199] The pressurized gas expands at or near isothermal expansion 153 and also accelerates the fluid.

[0200] Because the heat capacity of a fluid per volume is much greater than that of a gas, the temperature of the gas-fluid combination does not change as much as it would if the gas alone expanded without the presence of the fluid.

[0201] The work generated potentially benefits from the mass of the accelerated fluid, which is typically larger than the mass of the gas.

[0202] Reference is now made to FIG. 1D, an illustration of a simplified block diagram of a heat engine in accordance with an illustrative embodiment.

[0203] FIG. 1D is intended to show a general heat engine in which a gas and a heated fluid are combined to produce work.

[0204] In the heat engine of FIG. 1D, gas 155 and heating fluid 156 are combined in combiner 157 .

[0205] The gas is heated by heat transfer from the fluid in a volume 158 that does not allow expansion of the gas. The heating is or near isochoric heating.

[0206] An isochoric process, also called a constant volume process, isochoric process, or isometric process, is a thermodynamic process in which the volume of a closed system undergoing such a process remains constant.

[0207] In some embodiments, the heat capacity of the fluid is much greater than the heat capacity of the gas, so the temperature of the gas-fluid combination does not change significantly.

[0208] Following isochoric heating, the pressurized gas is allowed to expand under near or near isothermal expansion 159, also accelerating the fluid.

[0209] The work generated potentially benefits from the mass of the accelerated fluid, which is typically larger than the mass of the gas.

[0210] Isothermal or near-isothermal compression and isothermal or near-isothermal expansion can be achieved. 100% isothermal work capacity is PVlan (P / P0) Joules. By mixing a fluid with the gas as it is compressed or expanded, the fluid's thermal mass is added to the gas, achieving 50% to nearly 100% isothermal compression and expansion. The fluid is optionally a very high temperature heat transfer fluid (HTF) that is compressed and / or expanded at temperatures above 50°C, above 100°C, or above 350°C, maintaining the gas temperature at approximately 750°C or higher, up to 1500°C. Substantially isothermal compression and expansion of the gas is achieved by mixing the liquid and gas in a chamber during the isothermal process. The large heat capacity of the liquid keeps the gas temperature nearly constant. For example, injecting air as bubbles into water or spraying water into the air are two efficient ways to increase the surface area between the air and water to enable isothermal expansion and compression of the air. The liquid can optionally be a high temperature heat transfer fluid, some non-limiting examples include oil at 700K or molten salt at 830K or above.

[0211] A large chamber at a constant temperature allows for slow pressure changes, making a very efficient isothermal process possible. Heat transfer between the fluid and gas through the bubbles or droplets is very high, making an isothermal process possible. The high heat transfer coefficient of gas bubbles in a fluid or fluid droplets in a gas allows isothermal expansion to be achieved as a rapid process. For example, a 10-fold volume expansion in 1 second can be achieved isothermally with an initial droplet size of 1 mm.

[0212] Various examples of heat engines that benefit from the properties of isothermal processes are described herein.

[0213] Some example aspects relate to the storage and conversion of solar energy and the conversion of waste heat to electricity.

[0214] Some example embodiments involve using a hot incompressible fluid (e.g., molten salt or thermal oil) mixed with a gas to isothermally expand the gas at high temperature to generate work.

[0215] One aspect of some embodiments relates to generating electricity. Hydroelectric turbines, in which pressurized water drives a generator, have a typical efficiency of 90% and are one of the most efficient and cost-effective energy converters.

[0216] Hydroelectric energy storage, in which water is pumped to high altitudes and used to generate electricity, has a power conversion efficiency of approximately 70% to 80% and is considered an efficient energy storage method.

[0217] Described herein are energy storage embodiments using chambers in which potential energy (altitude difference) is converted into pressure and temperature differences. In such exemplary storage systems, water or some other fluid is pumped from a low-pressure chamber to a high-pressure chamber by a hydropump. The high-pressure chamber contains air or some other compressible gas within a sealed chamber. In some embodiments, the air is adiabatically compressed (isentropically), and the compression of the air also heats the air; thus, the compressed, heated air stores energy in the form of heat and pressure. In some embodiments, the air is compressed and heated both by the compression alone and by a heat source (e.g., solar, waste, or geothermal), and the compressed, heated air stores energy in the form of heat and pressure. During the discharge phase, water flows from the high-pressure chamber through a hydroelectric turbine to the low-pressure chamber, recovering energy. In terms of electricity, such systems recover most of the electrical energy. Such systems have reported round-trip efficiencies of approximately 70% to 80%.

[0218] Before describing at least one embodiment of the present disclosure in detail, it is to be understood that the disclosure is not necessarily limited in its application to the details of construction and arrangement of components and / or methods set forth in the following description and / or illustrated in the drawings and / or examples. The disclosure is capable of other embodiments or of being practiced or carried out in various ways.

[0219] Exemplary embodiment methods and systems using large high temperature and pressure chambers

[0220] Reference is now made to FIG. 1E, which is a simplified diagram of an exemplary embodiment.

[0221] FIG. 1E shows a system including low pressure chambers 1, 4, high pressure chambers 2, 3, a pump 110, and a turbine 112 for using thermal energy to compress air and convert it into electricity.

[0222] As a general example, consider the hydroelectric energy storage system shown in Figure IE, which includes a first chamber 1 at ambient pressure and temperature. By way of a non-limiting example, first chamber 1 may be a 50 cubic meter tank at least partially filled with a fluid 114 at a pressure of 1 bar and a temperature of 300 K. First chamber 1 is connected through a pump 110 to a second chamber 2 that is at least partially filled with a gas 116, e.g., air.

[0223] Actuating pump 110 forces fluid 114 into second chamber 116, optionally isothermally compressing gas 116. The pumped fluid is shown as fluid 122 in second chamber 116.

[0224] From second chamber 116, pressurized air can optionally be filled into chamber 5 and stored under pressure in chamber 6.

[0225] In some embodiments, isothermal compression within chamber 6 may release heat to the environment, as indicated by arrow 121 .

[0226] Reverse pressure release from chamber 6 to a second chamber 2 that is at least partially filled with a fluid 122, e.g., water 122, can drive a water turbine (not shown) to generate electricity (not included in the drawings).

[0227] High pressure gas can be stored and used to feed turbines and convert them into electricity.

[0228] In some embodiments, the third chamber 3 contains a hot liquid 124, for example molten salt at 850K or thermal oil at 700K or water under pressure at a temperature just below its boiling point.

[0229] Turbine 112, in some embodiments a turbine that is chemically resistant and designed for the working fluid and operating temperature, is used as a hydroelectric turbine to generate electricity by converting rotation caused by the flow into electricity. Turbine 112 is connected to a third chamber 3 and to a fourth chamber 4 at low pressure, for example, ambient pressure or 1 bar.

[0230] Such designs may use Francis turbines, Kaplan turbines, Pelton wheels, Tesla turbines, and similar designs used for hydroelectric turbines for the turbine 112, and in some embodiments may use materials typically used for molten salt and / or high temperature thermal oil pumps.

[0231] In some embodiments, the electricity generated by the turbine 112 can be used to operate the pump 110 .

[0232] In some embodiments, the turbine 112 is optionally connected by a shaft 126 to the pump 110 directly or by a gear to control the flow rate of the pump 110. Work is generated as the pressure in the third chamber 3 increases, and the shaft 126 drives the pump 110.

[0233] Exemplary operating conditions for the system shown in FIG. 1E may include, by way of some non-limiting examples:

[0234] Water at room temperature and / or ambient pressure in a first chamber 1, referred to herein as State 1, is pumped into a second chamber 2, which may have air 116 in whole or in part, and the air may be isothermally compressed to a pressure above ambient, such as 40 bar, 100 bar, 300 bar, or other value, referred to herein as State 2.

[0235] In some embodiments, isothermal or near isothermal compression can be optionally maintained by spraying water in the second chamber 2 or circulating air bubbles in the second chamber 2 under increasing pressure.

[0236] In some embodiments, isothermal compression is maintained if the heat capacity of the water is significantly greater than the heat capacity of the compressed air. Such a condition is optionally achieved using a sufficient amount of water.

[0237] The water compresses the air and causes it to flow from the second chamber 2 through air pipes into chambers 5 and 6.

[0238] In some embodiments, chamber 5 is optionally smaller than chamber 6, possibly by a ratio defined by the operating temperature.

[0239] In some embodiments, chamber 5 is optionally used to drive turbine 112, and chamber 6 is used to further store compressed air that can later be used to drive turbine 112 to generate electricity between second chamber 2 and first chamber 1.

[0240] In some embodiments, water spray can be used in chambers 5 and / or 6 to cool the compressed air to allow isothermal compression.

[0241] In some embodiments, chamber 5 has a heated pipe inlet, and the flow of molten salt through the heated pipe optionally increases the temperature. As the temperature increases and chamber 5 is sealed, the pressure increases. At 300 K and 40 bar, a pressure of 113 bar at 850 K is reached, referred to herein as State 3.

[0242] In state 3, the third chamber 3 is optionally partially filled with molten salt. The pressure in the third chamber 3 is increased to 113 bar by opening the air flow between the third chamber 3 and chamber 5, optionally without flow.

[0243] When flow is allowed between the third chamber 3 and the fourth chamber 4, work is generated and, in some embodiments, rotates the shaft 126. Within the fourth chamber 4, the air expands isothermally to ambient pressure, reaching a state referred to as State 4.

[0244] In some embodiments, the isothermal expansion of the air is achieved by spraying molten salt or circulating gas bubbles in the third chamber 3.

[0245] Optionally, high pressures can be avoided by initially setting a lower pressure in chamber 3, e.g., initially 15 bar at 300 K, then 42.5 bar at 850 K, or any other pressure that results in the desired energy conversion. A numerical example is calculated as follows:

[0246] Numerical example for 113 bar: First chamber 1 and second chamber 2 each have a size of 50 cubic meters. A volume of air at 1 bar pressure is compressed in second chamber 2 to a volume of 1.25 cubic meters of air at 40 bar in this example. This isothermal compressed air is taken into chambers 5 and 6 at room temperature. Once the air is compressed, the chambers are sealed and, optionally, water is discharged from second chamber 116 to first chamber 1 for reuse in compressing the air into chamber 6, and optionally into the cassette in chamber 6.

[0247] Focusing on chambers 5 and 6, the molten salt is at 850 K compared to room temperature of 300 K. Such a ratio leads to a ratio of the work that can be done by the isothermal process, which leads to a desired size ratio between the two chambers.

[0248] The work required to compress air to 40 bar is

number

[0249] A portion of the molten salt is used to heat air taken in at 40 bar in chamber 5. After the air has been heated to 850 K at a pressure of 40 bar in chamber 5, the pressure increases by the temperature ratio to 40*850 / 300=113 bar, and the total work that can be done by the same volume of air through isothermal expansion increases by the following factor:

number

[0250] The above calculations show that only 1 / 3.62 = 27% of the compressed air is potentially required to generate the work of compression. The volume of the heating chamber 5 in this example is only 27% of the volume of compressed air in the second chamber 2.

[0251] In the example of 1.25 cubic meters of compressed air at 40 bar in second chamber 2, chamber 5 may be 0.345 cubic meters and chamber 6 may be 0.9 cubic meters.

[0252] To extract work from the hot compressed air, the hot compressed air is injected, optionally as bubbles or by other mixing methods, into a third chamber 3, which is optionally filled completely with molten salt, thereby pressurizing the chamber 3 to 113 bar. The pressure of the molten salt in the third chamber 3 optionally induces a flow, driving a turbine 112 to generate work. The pressure reduction along with the flow causes an isothermal expansion of the air volume.

[0253] In some embodiments, mechanical work is optionally transferred by shaft 126 to a cooler (e.g., 300 K) portion of the system, where pump 110 optionally compresses the air isothermally. As calculated above, this work is potentially sufficient to compress the entire 50 cubic meters of air from ambient pressure to 1.25 cubic meters at 40 bar, filling chambers 5 and 6.

[0254] The above process optionally continues until all chambers 6 are filled.

[0255] In some embodiments, the chamber 6 may be, for example, 50 m 3 The energy can be one large chamber with a volume of 100 psi, optionally partially discharging as chamber 3 empties and refills. The process is optionally repeated until the pressure in large chamber 6 drops to, for example, ambient pressure. Using such a large chamber can be cost-effective. This energy can fill 3.62 chambers 6 with compressed air at 40 bar. Chamber 1 is at 1 bar, and chamber 2 is at 40 bar, allowing compressed air to be stored in chambers 6.

[0256] In some embodiments, the chamber 6 may be several chambers. In some embodiments, valves allow pressurized gas to flow individually into one or more of the several chambers 6, and pressurized gas to flow individually out of one or more of the several chambers 6.

[0257] In some embodiments, having two chambers 5, 5B allows one chamber to be compressed (filled) while the other chamber is decompressed (discharged), potentially allowing for more continuous flow in the turbine 112 and pump 110.

[0258] In some embodiments, the system is augmented to increase overall capacity.

[0259] Optionally, more than one chamber 5, 5B may be used simultaneously for discharge, increasing the power output of the turbine 112.

[0260] Note that in some cases the air is optionally at ambient temperature when it enters chamber 5. This can be achieved by pre-cooling second chamber 2 with water spray or a heat exchanger.

[0261] In some embodiments, instead of refilling the second chamber 2 and the third chamber 3, the direction of the pump 110 and the turbine 112 is optionally reversed, so that the high-pressure chambers become the first chamber 1 and the fourth chamber 4. Optionally, air flow can be directed into the new, higher-pressure first chamber 1 and the fourth chamber 4. In such a scenario, once the third chamber 3 is emptied and the fourth chamber 4 is filled, the fourth chamber 4 is optionally sealed, and air is optionally injected into the fourth chamber 4 to increase its pressure. The flow from the fourth chamber 4 can drive the turbine 112 while returning to the third chamber 3. This cycle optionally repeats, with the chambers acting like a two-piston engine, pushing the turbine in the same direction of rotation.

[0262] In some cases, the change in pressure gradient does not necessarily cause turbine 112 and pump 110 to operate in the opposite direction. In some embodiments, the operating direction can be maintained by additional piping connecting new high-pressure chambers 1 and 4 to the same high-pressure side of pump 110 and turbine 112, such as when chambers 2 and 3 are at high pressure.

[0263] Reference is further made to FIG. 2, which shows a PV diagram and a TS diagram of an exemplary embodiment.

[0264] FIG. 2 illustrates the thermodynamic processes occurring in the exemplary embodiment system as a PV (Pressure-Volume) diagram 202 and a TS (Temperature-Entropy) diagram 222 .

[0265] PV diagram 202 shows the volume [m 3 ] and Y axis 203 of pressure [bar].

[0266] The TS diagram 222 has an X-axis 224 of entropy S [MJ / K] and a Y-axis 203 of temperature [Kelvin].

[0267] The values ​​shown in diagrams 202, 222 are according to the exemplary embodiment described below, and the processes described are those of the exemplary embodiment.

[0268] In State 1 (references 206, 226) above, the system is at 300 K and air is isothermally compressed, for example to 40 bar, optionally with the injection of a water spray. By injecting water at or near the same temperature as the air, the large heat capacity of the water keeps the compressed air at a near constant temperature as the pressure is reduced, hence the expansion is called isothermal.

[0269] As the heat leaves the system (see Q1(Out) 211), the system reaches State 2 (references 207, 227).

[0270] Air is then injected as bubbles into the molten salt at, for example, 850 K, potentially exhibiting ideal or near-ideal gas expansion. As a non-limiting calculation example, consider a pressurized air volume of 50 cubic meters at 40 bar.

[0271] Air expands slowly as its volume increases due to the flow. Air is heated at constant volume,

number

[0272] Finally, as the molten salt flows towards the lower pressure, the bubbles or sprays produce work through isothermal expansion, increasing in volume and driving the turbine. The system relaxes to ambient pressure of 1 bar at State 4 (209, 229).

[0273] In some embodiments, as shown in FIG. 1E, turbine 112 is optionally connected by shaft 126 to pump 110, which optionally isothermally compresses air between state 1 and state 2.

[0274] The same process is shown in TS diagram 222.

[0275] In some embodiments, the pump 110 is electrically driven and the turbine 112 between the third chamber 3 and the fourth chamber 4 is connected to a generator motor as well as other turbine electrical systems.

[0276] Example of total efficiency calculation:

number

[0277] The potential loss in the system is 850K of heat in state 4, which can be described by the following equation:

number

[0278] Q4 is the heat input to the gas to heat it to a temperature equal to the temperature of the fluid.

[0279] In some embodiments, this heat can optionally be recaptured by heating air at State 2 or by heating water during eventual power generation in a turbine.

[0280] The hot water at this stage may be highly expansive compared to ambient temperature. The water at this stage may optionally be brought to 90 degrees Celsius, for example, using waste heat.

[0281] The efficiency achieved by isothermal expansion can reach 90%. Isothermal expansion is about half the efficiency of the full compression-expansion cycle described above, and without heat recovery as described above,

number

[0282] By recapturing 50% of the Q4 heat (Q4 is the heat used to heat the gas exiting the system, which recapture is optionally achieved by using a heat exchanger between the exiting air at 850K and chamber 5), the efficiency is

number

[0283] Power Consumption

[0284] In some cases, it is actually desirable to inject a large amount of air to increase productivity, at the potential cost of lower air temperature.

[0285] In some embodiments, thermal compensation is optionally provided, for example, by concentrated photovoltaics at the solar receiver. For solar applications, heat transfer fluid (HTF), such as molten salt, thermal oil, etc., from the solar receiver can be used as the thermal fluid in chambers 3 and 4 to drive the heat engines.

[0286] In some embodiments, two different fluids may optionally be used. In some embodiments, a heat exchanger is used to transfer heat from the solar HTF to the engine HTF.

[0287] In solar applications, an engine such as pump 110 in FIG. 1E runs all day and stores power as compressed air (or other gas) in a chamber such as chamber 6, which can later be converted into electricity using a water turbine.

[0288] In some embodiments, the engine may be operatively connected to an electrical generator, such as a turbine 112, and the generated electrical energy may be stored in a battery.

[0289] In some embodiments, a thermal storage reservoir may be part of the solar energy system, and the HTF of the turbine 112 may receive heat from the thermal storage reservoir, allowing for continuous operation.

[0290] In some embodiments, the temperature rise of the engine HTF depends on the cooling rate of the engine HTF, which depends on the capacity (power produced) and heat loss of the engine. In some embodiments, the heat exchange between the solar HTF and the engine HTF can occur on each cycle or as the engine HTF cools.

[0291] In some embodiments, the heat source is waste heat from an industrial heat source.

[0292] In some embodiments, a geothermal heat source may be used.

[0293] In some embodiments, as a non-limiting example shown in Figure IE, the temperature of the molten salt in chamber 3 drops as the air expands, for example from 850 K to 700 K. This 150 K drop can optionally be compensated for by a heat source (for example, a solar receiver).

[0294] In some embodiments, the temperature difference in the HTF is less than 1 degree due to the large heat capacity of the HTF compared to the work produced per cycle. In such cases, chambers 3 and 4 can perform hundreds of cycles before cooling down and requiring reheating of the oil.

[0295] In an exemplary embodiment for solar applications, the above allows the solar HTF to reheat the engine HTF after many cycles (tens or hundreds of cycles). The extended time to heat up results in a potential reduction in mass flow rate and / or a potential reduction in cost due to a reduced number of reheat events.

[0296] In some embodiments, after chamber 3 is emptied, as part of the refill process, a pump (not shown) circulates molten salt (fluid 128) from chamber 4 through solar receiver 130 and back to chamber 3, where the temperature of the molten salt (liquid 124) potentially rises, optionally back to 850 K. In such an example, Q2 + Q3 = 37015 MJ (1031 kWh) is the receiver's heat input over the duration of each cycle. For a one-hour cycle, this translates to 1.031 MWh.

[0297] Rate discussion

[0298] In the above example, the receiver is 3 The discharge of the air chamber 6 generates heat of Q2+Q3=1.031 MWh.

[0299] In some embodiments, for example, for a solar receiver or waste heat collector with a thermal power of 1.03 MW, 3 Chambers 1 and 2 can be fully pumped in one hour. At the same time, the system optionally fills 3.62 such chambers to 40 bar during that hour, with Chambers 1 and 2 optionally operating for 113 cycles. Implementing such a rate may be difficult. Increasing the number of chambers in the system can support similar heat input power over longer cycle durations. For example, a system of 10 Chambers 1 and 10 Chambers 2 used with the same 1 MW receiver would receive the same total heat input power of 1 MW, potentially allowing for 5 minutes per cycle. Dividing a system like the one shown in Figure 1E into two groups of five subsystems may allow one set of five chambers 6 to be pumped while the other set of five chambers 6 is filled.

[0300] In some embodiments, by adding multiple systems in parallel, the duration of the cycle can be extended to any desired period.

[0301] In some embodiments, during the final discharge of chamber 6 through the turbine, a 1.03 MW solar receiver can potentially provide 1.03 MWh*0.45*6 hours=2.781 MWh / day of electricity without heat recovery, or 1.03 MWh*0.55*6 hours=3.4 MWh / day at 55% efficiency when 50% of the heat is recovered.

[0302] Dynamic Power Range:

[0303] The molten salt turbine and water pump can potentially operate over a wide range of pressure differentials. For example, during the first discharge cycle, the pressure difference between chambers 3 and 5 is 113 bar and drops to about 2 bar, while during the final discharge cycle, the pressure difference is <10 bar and drops to about 2 bar. The pump can potentially produce pressures from 2 bar to 40 bar.

[0304] To overcome such challenges, some embodiments may optionally use a Kaplan turbine, which can optionally change the angle of the blades in response to changes in pressure differential, which may increase the range of optimal pressure differential.

[0305] Optionally, when using a Pelton wheel, the nozzles designed to convert pressure into kinetic energy of the flow can be adjusted and / or replaced with different nozzles depending on the pressure differential between and within cycles.

[0306] Optionally, gears between the pump and turbine can convert power as needed to keep both the pump and turbine operating optimally.

[0307] Reducing the pressure in the high temperature chamber (3):

[0308] Molten salt (or other high temperature fluid) drives the pump and storage. In the above example, the work done is 2670 MJ, which can be achieved by molten salt at various pressures and volumes according to the following formula:

number

[0309] 50m operating at 113 bar 3 An exemplary list of possible pressure and volume values ​​corresponding to the above example of a volume of 0.01 MPa includes the following: [Table 1]

[0310] Reduction of hot chamber volume and pressure by sequential air injection.

[0311] Thus far, we have described a balanced system in which all chambers may be simultaneously refilled by hot and cold cycles, optionally including a molten salt chamber 3 having a volume on the order of that of the water chamber 2, e.g., the volumes listed in the table above.

[0312] In some embodiments, chamber 5 optionally contains enough air to fill chamber 3 .

[0313] In some embodiments, the molten salt in chamber 3 allows the input and output cycles to be completed faster than the input and output cycles of water chamber 1, potentially reducing the volume of chamber 3 by the ratio of input cycle time to output cycle time.

[0314] In some embodiments, the duration of the cold cycle is optionally kept synchronized with the duration of the hot cycle, for example, a ten times faster fill-drain results in a ten times smaller volume for chamber 3 and chamber 5.

[0315] In some embodiments, smaller chambers 3, 4, and 5 may optionally be used, for example, with the system shown in FIG.

[0316] Reference is now made to FIG. 3, which is a simplified diagram of an exemplary embodiment.

[0317] FIG. 3 shows a system including cold chambers 301, 302, hot chambers 303, 304, a pump 310, and a turbine 312 for using thermal energy to compress air and convert it into electricity.

[0318] FIG. 3 shows an exemplary embodiment that uses high-rate high-temperature cycling to reduce the volume of chambers 3, 4, and 5 shown with reference to FIG. 1E.

[0319] FIG. 3 shows the cassette of chamber 6 of FIG. 1E replaced with an optionally larger chamber 306.

[0320] In some embodiments, chamber 305 is optionally attached to the bottom of chamber 303 .

[0321] A non-limiting example of energy flow in the system of FIG. 3 will now be described.

[0322] Water at ambient temperature (e.g., about 300 K) and / or pressure in chamber 301 in State 1 is pumped into chamber 302, which may contain, in whole or in part, air 316, and the air may be isothermally compressed to a pressure above ambient pressure, such as 40 bar, 100 bar, 300 bar, or other value at ambient temperature, by being exposed to a fluid with a large heat capacity that maintains a nearly constant temperature throughout the expansion, transitioning from State 1 to State 2. The compressed air in State 2 is optionally stored in chamber 306 in State 2, for example, at a pressure of 40 bar and ambient temperature, e.g., 300 K. In some embodiments, the air is exposed to the fluid in chamber 3 by bubbling. In some embodiments, the fluid is sprayed into the air in chamber 3.

[0323] Pressurized air is optionally sent from chamber 306 to chamber 305, after which valve 315 is closed and hot fluid or air or fluid / gas mixture heated by heat source 314 is sent to chamber 315 and / or chamber 303, heating the pressurized air as the fluid / air mixture reaches state 3 within chamber 303. For example, chamber 303 is heated to a temperature of 850 K and a pressure of 113 bar, with a pressure of 0.02 m 3 The molten salt is contained in the

[0324] Molten salt at a temperature of 850 K and a pressure of 113 bar is used to drive turbine 312 and is pumped into chamber 304, losing pressure and / or temperature. By way of non-limiting example, chamber 304 may contain molten salt at a temperature of 700 K and an ambient temperature, e.g., 300 K.

[0325] In some embodiments, the chamber 304 is 0.02 m 3 may have a volume of

[0326] In some embodiments, the heat source 314 may be a solar receiver and / or some other heat input.

[0327] In some embodiments, a shaft transfers energy from the turbine 312 to the pump 310. In some embodiments, the turbine 312 generates electricity, which is supplied to the pump 310 in addition to other users of the generated electricity.

[0328] Such designs may use for the turbine 312 Francis turbines, Kaplan turbines, Pelton wheels, Tesla turbines, and similar designs used in hydroelectric turbines.

[0329] In some embodiments, prior to filling chamber 303, chamber 305 is optionally filled with cold air, for example and without limitation at a pressure of 40 bar. Chamber 305 may remain hot from a previous cycle. In such a case, the heat transfer rate between the air and the walls of chamber 305 is optionally designed to be slower than the rapid filling of chamber 305 with air and sealing of chamber 305.

[0330] For example, air at a pressure of 40 bar is added to the air in chamber 305. The air is heated to a pressure of 113 bar in chamber 305. If the volume of chamber 303 is 20 liters, chamber 305 can optionally have a volume of 20 liters / 113 = 0.18 liters.

[0331] When the valve between chambers 306 and 305 is opened, the pressure can equilibrate quickly, eg, within milliseconds, faster than typical heat transfer rates, and the temperature rise can be eliminated or greatly reduced.

[0332] In some embodiments, several such chambers 305 and 303 are used sequentially so that continuous or near continuous powering of the turbine is achieved. Similar to a car engine, there are optionally two, three, four, or other numbers of chambers, optionally filled at different times, and optionally with equal phase differences between their cycles.

[0333] In some cases, an additional piping system is used, optionally connected in reverse (e.g., chamber 303 is connected to the low pressure side of turbine 312, chamber 304 is connected to the high pressure side of turbine 312, and similarly for chambers 301 and 302). In such cases, when chambers 303 and 301 are empty, valves are flipped to switch between chambers 301 and 302, and between chambers 303 and 304. In such an exemplary configuration, chamber 304 is also optionally connected at its bottom to chamber 305. As in the previous example (50m 3The pumping time for each chamber 303 for the same power generation may be proportional to the size and number of chambers. For 10 chambers of 20 liter volume (for each chamber 305 and 303), the pumping time may be 10*3600 / 50000*20=14 seconds.

[0334] A trade-off between volume and pressure can also be made by using high velocity air injection to reduce pressure while increasing the size of chambers 303 and 305 .

[0335] Converting heat into work by creating a vacuum

[0336] Thus far, methods have been described for using heat to create a pressure gradient to generate mechanical work. These methods have involved the use of high temperature and high pressure chambers, which can be expensive. Furthermore, turbines, which operate at high temperatures and with media that can be corrosive, can be expensive. There may be advantages to eliminating the use of turbines and / or the use of high temperature and / or high pressure chambers.

[0337] Reference is now made to FIG. 4A, which is a simplified diagram of a system for converting heat to work by creating a vacuum, according to an illustrative embodiment.

[0338] Figure 4A shows a system that is partially similar to the system of Figure 3. The parts that are similar to Figure 3 are chamber (1) 401, pump 410, chamber (2) 402, and chamber (6) 406.

[0339] FIG. 4A also shows chamber (3) 403 and valve 415, which allows either chamber (2) 402 or chamber (6) 406 to supply pressurized gas to chamber (3) 403, depending on the setting of the valve.

[0340] FIG. 4A illustrates, by way of example and not limitation, a 50 m volume filled with water at ambient conditions, e.g., 300 K and 1 bar. 34 shows chamber (1) 401 at ambient conditions. The selection of ambient conditions is merely an example. A pump 410 transfers water from chamber (1) 401 to chamber (2) 402, which contains sealed air or some other gas. The air is isothermally compressed by the pumped water, for example, by using a water spray or by circulating air bubbles in the water. As a non-limiting example, compressed air at 40 bar is optionally collected in chamber (6) 406. The compressed air from chamber (6) 406 is used to increase the pressure in chamber (3) 403, for example, to 40 bar.

[0341] Hot air from an optional solar receiver 414 or some other heat source, such as a waste heat source 414, is optionally transferred to chamber 4. The hot air has a temperature of 850K, as a non-limiting example.

[0342] The chamber (4) 404 is optionally sealed and the air is optionally cooled to ambient temperature, for example 300K, by spraying with water.

[0343] In some embodiments, water from chamber (3) 403 is provided to act as cooling water. The pressure in chamber (4) 404 can be reduced from 1 bar to 0.353 bar by a factor of 300K / 850K. Turbine 412 performs mechanical work by converting the pressure difference between chamber (3) 403 and chamber (4) 404 into rotation of shaft 416.

[0344] Such designs may use for the turbine 412 Francis turbines, Kaplan turbines, Pelton wheels, Tesla turbines, and similar designs used in hydroelectric turbines.

[0345] It should be noted that the work done by turbine 412 is proportional to the natural logarithm (ln) of the pressure difference across the turbine, and therefore reducing the pressure in chamber (4) 404 by approximately a factor of three increases the potential work done by approximately ln(3) = approximately 1.1, e.g., adding approximately ln(40 bar / 1 bar) = ln40 = approximately 3.7, resulting in an improvement in work of approximately 1.1 / 3.7 = approximately 30%.

[0346] In some embodiments, the expansion of the air or gas within chamber (3) 403 is an isothermal process in which the fluid maintains a near-steady state temperature.

[0347] In some embodiments, the expansion of air or gas within chamber (4) 404 is an isothermal process in which a near-constant temperature is maintained by the atomization of water or other fluid.

[0348] The vacuum method may use repeated cycles of refilling the chamber.

[0349] Power regulation between turbine and pump

[0350] In some of the described methods and systems, a shaft is optionally connected between the turbine that generates the work and the pump that is used to compress the air to generate the work. Using a shaft to directly connect the turbine and the pump may not allow for power regulation between the pump and the turbine.

[0351] In some cases, the shaft is optionally connected to a gearbox (not shown) that provides several options for the rotational speed ratio between the turbine rotation and the pump rotation, allowing a wider dynamic range to potentially achieve higher efficiencies.

[0352] In some cases, the gearbox can optionally cover the entire range of rotation ratios associated with the maximum pressure required on the pump side, which in the example above is 40 bar, with the minimum pressure difference across the turbine.

[0353] In some embodiments, the hydropump includes a pressure compensation pump to allow for compression of air over a wide range of pressure differentials.

[0354] In some embodiments, air is compressed from 1 bar in chamber 301 to 40 bar in chamber 302, with the pump providing a pressure differential between 1 and 40 bar.

[0355] In the example described, for example, when chamber 6 306 in Figure 3 is nearly empty and has a pressure of, say, 2 bar, the pressure of the gas increases after heating to, say, 4.7 bar at 700 K, so that the turbine also operates during the last cycle. In such a case, the system in Figure 3 can use a gear ratio of 10, where the turbine is 10 times faster than the pump, to provide enough energy for the pump.

[0356] In some embodiments, as the pressure differential across the turbine decreases, the gear ratio between the turbine and the pump increases.

[0357] At the other end of the pressure change during use of chamber (6) 406, during the first cycle of the system, chamber (6) 406 has a pressure of, for example, 40 bar, which is heated in chamber (3) 303 of Figure 3 and increases to 93 bar.

[0358] In some cases, at that point, the pump 310 may operate on a substantially empty chamber (2) 302 in Figure 3. Under such conditions, the rotation ratio is about 1 / 10, making the pump faster.

[0359] In some embodiments, achieving a double-order dynamic range (ratio of 0.1 to 10 over the rotational range) can be achieved with pump designs such as Kaplan pumps, which may allow for a wider efficiency range by varying the angle of the turbine blades.

[0360] In some cases, the turbine is a Kaplan design turbine.

[0361] Reduced operating pressure

[0362] In some systems, it may be preferable to operate at lower pressures than those listed above. For example, injecting 17.6 bar cold air into 370°C thermal oil will produce a 40 bar operating pressure driving a 40 bar turbine. In another example, injecting 8.75 bar cold air into 370°C thermal oil will produce a 20 bar operating pressure, allowing the turbine to be driven by a turbine designed for 20 bar.

[0363] Maintaining high turbine efficiency through dynamic load changes with pressure drop

[0364] When the high-temperature chamber (3) 303 in FIG. 3 or the high-temperature chamber (4) 403 in FIG. 3 discharges, the pressure drops from its maximum to a lower pressure, optionally to a minimum value at which the turbine 312 can operate. The lower pressure can be near ambient pressure or somewhat higher. As the pressure drops, the velocity of the HTF exiting the nozzle and driving the turbine decreases. For a turbine, maximum efficiency occurs when the fluid velocity is twice the turbine's tangential velocity. Conventional turbines typically operate for a constant load defined by the system's head pressure. In such conventional systems, a drop in pressure for a constant load (corresponding to a high pressure) slows the turbine's rotation and reduces its efficiency. In some cases, the turbine is connected to a power generation unit. In such cases, the turbine's load is defined by the amount of power it produces. Reducing power generation in line with the pressure drop can maintain the linear velocity of the turbine blade tips at 50% of the fluid velocity, maintaining maximum efficiency. This effect can be achieved by the power generation unit's electrical control system. Optionally, a mechanical element such as a piston driven by the pressure of the HTF can control the electrical load and replace the electrical control system, since the reduction in load coincides with a reduction in pressure.

[0365] Such control is analogous to an electric vehicle's generator connected to the brakes of an electric vehicle: Higher brake pressure causes the generator to generate more electricity (by increasing the load, it produces more electrical energy). Reducing brake pressure reduces the load on the generator.

[0366] In some embodiments, the turbine is connected by a shaft to a pump that stores the energy as compressed air. In such cases, the mechanical element that reduces the load on the turbine as the pressure of the HTF decreases is similar to a brake pad on a car. As the pressure across the turbine increases, the load to maintain the turbine's speed at an optimal value relative to the speed of the HTF increases.

[0367] In some embodiments, mechanical gearing between the turbine and the pump may maintain optimal turbine speed across the entire dynamic pressure range, or at least better turbine speed across the dynamic pressure range than without gearing.

[0368] In some embodiments, a pressure compensated pump is used to efficiently pump over a wide range of pressure differentials.

[0369] One aspect of the examples described herein takes as an example the combination of air as the compressible gas with fluids such as water and / or thermal oil and / or molten salt. However, such concepts can be implemented with any gas, such as CO, N, steam, etc. The heat transfer fluid can be any useful fluid, such as those used in concentrated solar power plants or nuclear power plants, including, for example, molten sodium.

[0370] The ideal Carnot cycle is based on an isothermal process, however the same concept can also be implemented through an isobaric expansion or compression of a gas which pushes a fluid in chamber 3 to drive a turbine.

[0371] In some cases, the demand-based release of compressed gas from chamber 6 into water chamber 3 is used to drive a hydroelectric turbine, which converts the pressure of the stored gas into electricity. In such a process, the expansion of the gas may depend on the temperature of the water.

[0372] In some embodiments, heating the water to a high temperature can improve the efficiency of the exemplary device. For example, 50 m 3 A gas at 200 K may have 25% more energy (converted to electricity) than a gas at 300 K under the same conditions. Taking advantage of the large heat capacity and low rate of heat loss of water, it may be possible to heat the water at the end of the energy storage phase.

[0373] In the solar receiver example, when the sun sets, the salt that received heat during the day may still be hot, but as molten salt it may not be hot enough to drive a turbine.

[0374] In some embodiments, residual heat from the salt is optionally transferred to the water chamber to raise the temperature of the water.

[0375] In some embodiments, the turbine has a minimum pressure value at which it can operate efficiently, and this minimum pressure can maintain the residual pressure of the hot gases and HTF in Chamber 3 or Chamber 4. This pressure can be recovered by connecting pipes between Chambers 3 and 4 and Chamber 2, bypassing the turbine and directly increasing the pressure in Chamber 2 for storage.

[0376] In some embodiments, the use of residual pressure occurs before the gas cools.

[0377] According to the example cycle above, chambers 3 and 4 are left with hot gas (e.g., air) after gas expansion is complete, and the heat of that air may be wasted when the chambers are refilled with HTF during the next cycle.

[0378] In some embodiments, heat loss is prevented by heating chamber 5 after filling it with compressed cold air. In such embodiments, the pressure in chamber 5 increases with heating, reducing heat transfer from the fluid, e.g., oil.

[0379] In some embodiments, such as solar applications, a larger chamber 5 is used that provides enough air to operate throughout the day. Such an air supply may be 10, 50, or 100 m 3 The temperature of chamber 5 may increase slightly by using the residual heat in chambers 3 and 4 to heat chamber 5 during each engine cycle, but the waste heat may be recycled. In some embodiments, chamber 5 is refilled at night using a hydropump.

[0380] Reference is now made to Figure 4B, which is a simplified diagram of a heat engine for use in an energy generation system according to an illustrative embodiment.

[0381] FIG. 4B shows a heat receiver 421, such as a solar receiver, optionally integrated with a thermal storage tank, chamber (0) 422, and an oil-driven HTF engine 423. In the exemplary embodiment of FIG. 4B, thermal oil, such as Therminol® 66, at a temperature of 400 degrees Celsius is used to drive a 100 kW turbine 423. A shaft 424 connects the turbine 423 to a pump 425, which compresses fluid in chambers (1) 426 and (2) 427, which contain an initial amount of air, to provide initial compressed air to one or more chambers (6) 428. In some embodiments, the shaft 424 is also connected to a generator 428 to generate electricity, which is stored in a battery 435 or fed to a grid 436.

[0382] Heated fluid, such as Therminol® 66, from the receiver 421 is collected in chamber (3) 431.

[0383] Compressed air from chamber (6) 428 or chamber (2) 427 is fed into chamber (5) 433A. When chamber (5) 433A is sealed, heated fluid from chamber (3) 431 is fed into chamber (5) 433A where it heats the compressed air and the pressure increases by a factor of the temperature. The heated fluid and gas flow to turbine 423 where work is produced and used as previously described.

[0384] Such designs may use for the turbine 423 Francis turbines, Kaplan turbines, Pelton wheels, Tesla turbines, and similar designs used in hydroelectric turbines.

[0385] In some embodiments, fluid is then charged into chamber (4) 432. When air pressure is charged into chamber (5) 433B and chamber (5) 433B is sealed, the fluid in chamber (4) 432 is supplied to chamber (5) 433B, increasing the pressure due to heating from the fluid from chamber (4) 432. The pressurized fluid and gas then drive turbine 423.

[0386] In some embodiments, the fluid returns to chamber (3) 431 to complete the cycle and start the cycle over again.

[0387] 4B includes an HTF reservoir chamber (7) 429. The HTF reservoir chamber (7) 429 optionally collects oil after one or more cycles in the turbine 423.

[0388] In some embodiments, at the end of the day, air pressure is used to transfer the HTF collected in HTF reservoir chamber (7) 429 to heat receiver 421 or chamber (0) 422 for reheating.

[0389] In some embodiments, chambers that may contain hot fluids and / or gases and pipes that may conduct hot gases are optionally insulated 430. The insulated components may optionally include chamber (3) 431, chamber (4) 432, chamber (5) 433A, 433B, and optional chamber (7) 429.

[0390] Calculations for a controlled volume of Therminol® 66 at 400°C designed for a 100kW solar receiver:

[0391] Consider the volume of air in the inertial reference frame.

[0392] Step 1: At ambient conditions, 3 m 3 Start with a controlled volume of air.

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[0393] According to the ideal gas equation PV=nRT, increasing the pressure of a gas from approximately 1 bar to 40 bar will increase its volume by 0.075 m 3 When the process is isothermal, the heat lost from the gas to the surroundings is Q1 = W1 = P1V1ln(V2 / V1) = 1.107 MJ.

[0394] Step 2: Heat the gas to 673 K with oil at constant volume. Assume the air to oil volume ratio is 4 / 96. Using 4% air instead of 2% results in less than 1% pressure loss and heat capacity

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[0395] The air and oil temperatures are both 673 K. The heat absorbed by the air is Q2=mC V ΔT=3.51Kg*0.81*373K=1.06MJ and the pressure increases to P2=673*40bar / 300=89.7bar for an ideal gas.

[0396] Step 3: For approximately isothermal expansion, the calculation is Q3=W3=V3P3ln(V4 / V3)=0.0375m 3 *89.7 bar*ln(89.7)=3.02MJ is.

[0397] The total energy expended is Q2 + Q3 = 1.06 MJ + 3.02 MJ = 4.08 MJ.

number

[0398] Q2+Q3=0.075m 3 The change in oil temperature due to oil and ΔT oil = 1 K. In some embodiments, the temperature of the oil drops by 1 Kelvin and can therefore be used again to further heat the gas in another cycle.

[0399] The ideal efficiency is

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[0400] In some embodiments, heat recovery from chamber 4 is achieved by a heat exchanger between exhaust air at operating temperature, for example about 400° C., and chamber 6 after it has been filled and sealed.

[0401] Q3=W3 is converted into kinetic energy of the fluid,

number

[0402] In an exemplary embodiment, 0.1 MW th Having a heat supply of (0.1 MJ / sec) means that the time it takes for chamber (3) 431 to empty and switch to chamber (4) 432 is 4.08 [MJ] / 0.1 [MJ / sec] = 40.8 seconds.

[0403] In some embodiments, such a solar receiver and HTF engine can use a thermal storage reservoir, where solar radiation is used to heat the thermal storage reservoir, which can then drive the HTF engine on demand.

[0404] In some embodiments, battery storage can be used instead of a thermal accumulator by powering the HTF engine when solar radiation is available and charging the battery for use when demand arises.

[0405] In some embodiments, compressed air in one or more chambers (6) 428 is used to store energy.

[0406] In some embodiments, when sunlight is unavailable for days longer than the aforementioned energy storage capacity, the HTF engine can run on hydrogen, biogas, natural gas, or any other fuel source. In this way, the system can operate 24 / 7 and replace energy systems that run solely on fossil fuels (gas, coal, etc.), allowing such systems to collect solar power when available, shift it to stored energy stored by the system, and eventually shift to fuel use when neither solar nor stored energy is available. Replacing fossil fuel turbines with a multi-source energy system can reduce the overall cost of the grid system.

[0407] In some embodiments, low quality waste heat at temperatures above ambient temperature, for example above 373 K, powers the HTF engine.

[0408] In some embodiments, hot water at a temperature below the boiling point can be used as HTF to drive a turbine, i.e., to convert pressure to electricity using a hydroelectric motor (not shown) connected to chamber (2) 427. In this case, the hot water increases pressure, increasing power output.

[0409] Description of chamber (3) 431, chamber (4) 432, and chamber (5) 433 in FIG. 4B:

[0410] In some embodiments, the use of chambers (5) 433A and 433B in Figure 4B is eliminated, and unheated pressurized air is supplied from the top of sealed chambers (3) 431 and (4) 432 before the heated fluid is supplied, heating the air and increasing the pressure. Eliminating chamber (5) 433 can reduce cost and complexity. Figure 4C shows optional configurations and chamber configurations for such a system.

[0411] Reference is now made to FIG. 4C, which is a simplified diagram of the use of a chamber to mix a heated fluid and a gas, according to an exemplary embodiment.

[0412] 4C shows chamber 441. Valve 442 can be opened to supply heated fluid to chamber 441. Valve 442 can then be closed. Valve 443 can be opened to supply compressed air to chamber 441. Valve 443 can then be closed to prevent loss of pressure. The heated fluid heats the compressed air in chamber 441 in an isochoric process because gas cannot expand and fluid cannot be compressed.

[0413] In some embodiments, chamber 441 also optionally has a pump 444 that mixes air and fluid within chamber 441. In some embodiments, pump 444 can pump fluid from the bottom of chamber 441 and spray the fluid onto the top of chamber 441.

[0414] In some embodiments, pump 444 draws air from the top of chamber 441 and injects it as bubbles into the fluid at the bottom of chamber 441, where the air is heated in the process of bubbling through the fluid.

[0415] Chamber 441 has an outlet 445 that, when opened, allows fluids and gases to rush into an engine, such as HTF engine 423 shown in Figure 4B.

[0416] Reference is now made to FIG. 4D, which is a simplified illustration of the use of two chambers according to an exemplary embodiment.

[0417] FIG. 4D shows chamber (3) 452 and chamber (4) 453 (without chamber (1) 426 and chamber (2) 427 as described with reference to FIG. 4B).

[0418] In some embodiments, partially filling chamber (4) 453 leaves enough volume to inject cold air instead of air from chamber (5) 433B in FIG. 4B. Once the cold air is injected, chamber (4) 453 is sealed and an optional oil spray pump (or bubble pump) as shown in FIG. 4C is activated until the air temperature reaches that of the oil. An oil valve is then opened, allowing oil to flow through a heat engine 459, such as a Pelton wheel shown in FIG. 4B, causing the heat engine to rotate. The oil is optionally drained through a drain back to chamber (3) 452.

[0419] In some embodiments, the oil passes through a collection chamber 451 .

[0420] In some embodiments, the oil passes through a heat storage tank 451 or solar receiver 451 for reheating. Reheating can occur with each cycle or after many cycles to increase the temperature differential.

[0421] Chamber (3) 452 is then sealed, cold air is injected and the process is repeated.

[0422] FIG. 4D shows a configuration in which two chambers can alternately supply heated fluid and gas to drive a heat engine.

[0423] FIG. 4D shows nozzles 457, 458, 459 for supplying flow to a heat engine 459.

[0424] Such designs can be used for heat engines 459, such as turbines, Francis turbines, Kaplan turbines, Pelton wheels, Tesla turbines, and similar designs used in hydroelectric turbines.

[0425] Reference is now made to FIG. 4E, which is a simplified diagram of the use of a chamber to mix a heated fluid and a gas, according to an exemplary embodiment.

[0426] 4E shows a vertically disposed chamber 483 with a thin pipe 484 that is open at the top and bottom. The pipe 484 is connected at the top to a plate 485 that divides the chamber 483 into an upper portion above the plate 485 and a lower portion below the plate 485.

[0427] Valve 481 can be opened to provide heated fluid to chamber 483. Valve 481 can then be closed.

[0428] In some embodiments, the heating fluid is provided so that it typically occupies approximately 95% of the volume of chamber 483 .

[0429] In some embodiments, the heating fluid is filled so that it does not extend above the plate 485 .

[0430] Valve 482 can be opened to supply compressed air to chamber 483. Valve 482 can then be closed to prevent loss of pressure. The heating fluid heats the compressed air in chamber 483 in an isochoric process because gas cannot expand and fluid cannot be compressed.

[0431] Heated fluid is located all around and inside pipe 484. When valve 485 at the bottom of chamber 483 is opened, heated and pressurized air expands through pipe 484, forcing the fluid out of chamber 483. As the air passes through the pipe, the expansion of the pressurized gas occurs nearly isothermally, during which the expanding gas must cool; in this case, the expanding gas receives heat from a source of high temperature and large heat capacity, namely the pipe and its surrounding oil.

[0432] Fluid exiting through valve 485 rushes into an engine, such as HTF engine 423 shown in FIG. 4B.

[0433] Reference is now made to FIG. 4F, which is a simplified diagram of the use of two chambers according to an exemplary embodiment.

[0434] FIG. 4F shows first and second chambers 470A and 470B, pipes 469A and 469B for supplying compressed air, a nozzle 466 for injecting the HTF stream into the Pelton wheel 465, an optional basin 467 for collecting spent HTF, and valves 468 for controlling the flow of gas and HTF.

[0435] FIG. 4F shows an exemplary configuration with two pipes for each chamber.

[0436] In some embodiments, partial filling of first chamber 470A with fluid leaves enough volume to inject air through pipe 469A. Once the air is injected, first chamber 470A is sealed and the temperature of the air reaches that of the HTF. Valve 468 is then opened, allowing the HTF to flow to a heat engine, such as a Pelton wheel 465, which rotates. The HTF optionally drains into basin 467 and from there into second chamber 470B.

[0437] In some embodiments, the HTF is optionally collected in basin 467.

[0438] In some embodiments, the HTF passes through a thermal storage or solar receiver (not shown) for reheating, which can occur with each cycle or after many cycles to increase the temperature differential.

[0439] The second chamber 470B is then sealed and cold air is injected through pipe 469B and the process is repeated.

[0440] FIG. 4F shows a configuration in which two chambers can alternately supply HTF to drive the heat engine.

[0441] 4E and 4F, and other exemplary configurations described herein, the HTF may flow into and out of the chamber by gravity. In some embodiments, a pump can pump the HTF into the chamber.

[0442] Such designs can use turbines, Francis turbines, Kaplan turbines, Pelton wheels, Tesla turbines, and similar designs used for hydroelectric turbines for the heat engine 465 .

[0443] Droplet size and velocity to maintain a near-isothermal process:

[0444] Q3 = W3 are the heat that needs to be supplied and the work that is produced, respectively, over the isothermal expansion process. The heat Q3 is transferred from the oil droplets to the gas (air or other gas). For simplicity, we show the example of a 15 kW Pelton wheel supporting a total net power output of 6 kW (leading to an efficiency of 40% due to the initial pressure input and losses), which can be applied to any other turbine.

[0445] The heat transferred is

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[0446] Note that in some embodiments, the heat transfer rate corresponds to the power generated.

[0447] In some embodiments, no control system is used to control the spray pump. In some embodiments, a shaft or separate mechanical or electrical wiring without a control system connects the main shaft of the Pelton wheel to the spray pump. When power generation is high, the spray pump operates at a high volume, and when power generation is low, the spray pump sprays at a low volume.

[0448] In some embodiments, a control system is optionally used to control the spray rate relative to pressure and flow rate changes at the Pelton wheel.

[0449] The parameters to consider in relation to oil atomization are droplet size and velocity: if the droplet size is too small, the heat capacity of the droplets will be reduced, which can lead to lower temperatures and reduced efficiency; if the droplet size is too large, the surface area to volume ratio of the droplets will be reduced, which can reduce the heat transfer rate.

[0450] In some embodiments, the change in droplet size is dependent on the velocity of the droplets provided to maintain a constant oil volume and / or mass and / or heat capacity ratio.

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[0451] Droplet size calculation:

[0452] The size of the droplet affects the terminal velocity of the droplet, the duration of the droplet in air, and the rate of heat transfer from the droplet.

[0453] For example, with an average pressure of 20 bar, an oil temperature of 673 K, and a temperature difference of 10 degrees before the oil returns to the flow, the following range of values ​​can be expected: [Table 2] Here, "Nu" represents the Nusselt number, and "t" represents the heating time to the final temperature.

[0454] The propagation distance in the table above is equal to the terminal velocity times the time to final temperature.

[0455] In some embodiments, one or more of the approximate size of the chamber, length, diameter, and width, are optionally selected to be equal to the propagation distance, which is the terminal velocity times the time to final temperature.

[0456] From the above calculations, we can see that for a chamber several meters in size, the effective diameter of the droplets is 5 mm or more, provided the air is maintained at a temperature at least 20 degrees lower than the oil temperature, where a 5 mm diameter droplet has a propagation length of 3.7 centimeters before its temperature drops by 10 degrees. Therefore, droplets larger than 1 mm in diameter can allow for a higher temperature difference.

[0457] Nozzle for mixing gas and fluid into a jet

[0458] In some cases, instead of mixing the gas and HTF in the chamber, the gas is optionally injected into the nozzle along with the flow of HTF.

[0459] One method of mixing air and fluid can be as described in the "Underwater two phase ramjet engine" (Hezi Varshay and Alon Gany, U.S. Patent No. 5,598,700), which proposes a motor for boats where air is injected into a nozzle and undergoes isothermal expansion, converting pressure into kinetic energy of the water.

[0460] However, the above propulsion uses water at ambient temperature.

[0461] Exemplary Embodiments of Jets

[0462] In some embodiments described herein, air and a hot fluid are mixed.

[0463] Reference is now made to Figure 5, which is a simplified illustration of the use of a nozzle as a heat engine in accordance with an illustrative embodiment.

[0464] FIG. 5 shows an exemplary embodiment in which a nozzle 530 suitable for operation with air and thermal oil at high temperatures, e.g., 700 K, can replace chambers 5 and 3 described with reference to FIG. 1E and further embodiments in which high temperature HTF is used to heat compressed air.

[0465] Air at ambient temperature, for example 300K, is optionally compressed in chamber 502 to for example 40 bar and, optionally without expansion, is heated in chamber 505 to a temperature of for example 700K, reaching a pressure of 93.3 bar.

[0466] High temperature thermal oil 521 at 700 K flows into nozzle 530. Air 522 at 700 K is injected into nozzle 530. As the air expands isothermally, the air pressure is converted into kinetic energy in the oil. The high velocity thermal oil optionally drives an engine such as a turbine 532 to generate work.

[0467] In some embodiments, the engine is a rotating Pelton wheel, optionally connected to a shaft 526, which optionally drives a hydropump between two chambers, such as chamber 501 and chamber 502, to generate pressurized air. In some embodiments, the pressurized air is stored in chamber 506. The above process is similar to that described in FIG. 1D.

[0468] Such designs can use turbines, Francis turbines, Kaplan turbines, Pelton wheels, Tesla turbines, and similar designs used for hydroelectric turbines for the heat engine 532 .

[0469] In some embodiments, the oil may be collected in a collection chamber 525 for reuse and / or to separate the oil from the air.

[0470] Note that the air does not need to be injected under pressure. The gas can be injected without pressure, and pressure can be created by heating without expansion, also known as isochoric heating. The gas can be injected without pressure, and pressure can be created by heating with limited expansion, which is close to isochoric heating.

[0471] A potential advantage of such a system and method over previously described systems and methods is the higher output power that can be extracted. Another advantage is more continuous operation (longer cycles), no need for large chambers 3 and / or 4, and no need for large amounts of heat transfer fluid. Fully continuous operation methods are also described.

[0472] Reference is now made to FIG. 6, which is a simplified diagram of an exemplary embodiment heat engine for use in an energy generation setting according to an exemplary embodiment.

[0473] Figure 6 shows a closed-loop cycle for a fixed jet configuration in which a gas 622, such as air, is injected into a nozzle 630 that receives the input of a heated HTF 621, forming an isothermally expanding bubble. The velocity of the HTF jet increases due to the expansion of the gas, converting the pressure of the heated gas into kinetic energy for the HTF.

[0474] In some embodiments, an engine 632, such as an impulse turbine or Pelton wheel, is used to convert the velocity of the HTF into rotation of a shaft 626 that drives a pump 610. The pump 610 optionally pumps a fluid, such as water, into the chamber 602, pressurizing the air within the chamber 602. In some embodiments, the pressurized air is stored in a storage chamber 606.

[0475] Such designs may use turbines, Francis turbines, Kaplan turbines, Pelton wheels, Tesla turbines, and similar designs used in hydroelectric turbines for the engine 632 .

[0476] In some cases, the air 622 injected into the nozzle 630 is optionally preheated in a heating chamber 605 to provide isochoric heating of the air in a sealed chamber. Optionally, the air is preheated by spraying the HTF or bubbling a gas through the HTF.

[0477] In some cases, a valve 607 is used to prevent high pressure gas from returning to the chamber 606 .

[0478] Optionally, a circulation pump (not shown) returns the HTF to the nozzle 630 after the engine 632, optionally at a desired pressure and velocity.

[0479] Optionally, the circulation pump passes the HTF through heat exchanger 627 for reheating. Optionally, the circulation pump replaces cold HTF with hot HTF from the regenerator.

[0480] An example of a rotating jet engine-like configuration

[0481] In some embodiments, the jets directly rotate a shaft that is connected to a generator and / or pump for generating air pressure and storing compressed air.

[0482] Reference is now made to Figures 7A-7D, which are simplified diagrams of a heat engine configured like a jet engine, according to an illustrative embodiment.

[0483] 7A shows a configuration of two jet nozzles 702A, 702B rotating within or above a ring-shaped HTF pool 704. A potential advantage of such a configuration is that it can generate power continuously (as opposed to some sealed chamber configurations where, in some embodiments, the pressure may decay exponentially with the duty cycle).

[0484] In various embodiments, one, two, or more nozzles can optionally rotate within or on a ring-shaped HTF pool 704 to generate rotational torque that is transmitted to a shaft 706 connected to a generator unit 708 or pump 708. Air is supplied 710 from an air supply 712, passes through a central axis, through arms 714, and reaches the nozzles 702A, 702B.

[0485] In some embodiments, the air expands isothermally within the nozzles 702A, 702B, causing the shaft 706 to rotate and generate work as electrical and / or mechanical work.

[0486] By way of example and not limitation, FIG. 7A shows a top view of two nozzles 702A, 702B rotating a main shaft 706 connected to a generator 708 or pump 708 or hydropump 708 .

[0487] In various embodiments, any number of nozzles 702 can be connected to generate more power.

[0488] In some embodiments, a valve 716 can be used to open and close to supply air from the air supply 712 to the nozzles 702A, 702B.

[0489] It should be noted with respect to Figure 7A, and with respect to Figures 8A-8C, 9, 10A, 10B, 11, and 14 described below, that the number of arms 714 and nozzles 702A, 702B is not limited to two. Any integer number of arms and nozzles should be understood, and two arms 714 and two nozzles 702A, 702B are merely a non-limiting example.

[0490] It should be noted that in some embodiments, compressed air from sources and / or chambers such as those described with reference to Figures 1E, 3, 4A-4F, 5, and 6 can be used to provide compressed air to power the heat engines described in Figures 7A-7D, 8A-8C, 9, and 14.

[0491] In some embodiments, compressed air is supplied from a source and / or chamber such as those described with reference to Figures 1E, 3, 4A-4F, 5, and 6, and the heat engines described in Figures 7A-7D, 8A-8C, 9, and 14 are optionally used continuously. This is in contrast to systems that fill a chamber with compressed air and then stop to refill the chamber from the source once the pressure in the chamber is depleted.

[0492] Some non-limiting example operating parameters for the configuration shown in FIG. 7A include:

[0493] Example 1: The HTF is at a high temperature, for example 670K, or in the range of 100C to 1500C, and the pressurized air can be supplied at a pressure of 5 bar and at a high temperature of 670K or in the range of 100C to 1500C.

[0494] Example 2: The HTF may be at a high temperature, for example 670 K, and the pressurized air may be supplied at a pressure of 5 bar and at ambient temperature. In some embodiments, the air is heated when mixed with the heated HTF.

[0495] Example 3: The HTF may be at ambient temperature, e.g., 21 C, and pressurized air may be supplied at 5 bar pressure and ambient temperature. In some embodiments, the pressurized air may be supplied from a pressurized air source. In some embodiments, the pressurized air source may be used to store energy in the form of pressurized air, as described with reference to Figures 1E, 3, 4A-4B, 5, and 6, and the configuration of Figure 7A may be used to generate energy, e.g., in the form of electricity.

[0496] The configuration of FIG. 7A may provide one or more of the following advantages:

[0497] It is not necessary to use an HTF pump to continuously supply HTF to the nozzles 702A, 702B. When the nozzles are operating, centrifugal force carries the HTF along the arm 714 to the nozzles 702A, 702B, and suction from the HTF carried to the nozzles draws the HTF from the HTF pool 704.

[0498] Operation of the nozzle can optionally be initiated by supplying heated HTF to the input of the nozzle, by a hand pump, or by a starter pump which does not need to be used if the arm is rotating.

[0499] In some embodiments, rotation can be initiated by supplying compressed air to the nozzle.

[0500] Note that as the arm 714 in the configuration of FIG. 7A rotates, the flow of HTF along the arm 714 toward the nozzles 702A, 702B is accelerated along the arm 714, creating a suction force that, in some embodiments, may serve to draw HTF from the HTF pool 704 toward the nozzles 702A, 702B.

[0501] The pressure profile along the radial arm 714 that supplies the HTF to the nozzles 702A, 702B increases along the arm 714.

[0502] In some embodiments, compressed gas is injected into the HTF at a location along arm 714.

[0503] In some embodiments, the flow of HTF along the arm can create a suction force that draws gas into the arm. The suction action of the flowing HTF plus the pressure of the pressurized gas creates a specific pressure at the injection location.

[0504] In some embodiments, the injection location is selected so that the HTF and gas flow outward along arm 714 , creating a suction force that draws the HTF from HTF pool 704 into arm 714 .

[0505] In some embodiments, the injection location is selected so that the flow of HTF drags the air bubbles toward nozzles 702A and 702B.

[0506] The pressure profile in the radial arm 714 that supplies the HTF to the nozzles 702A, 702B increases along the radial arm, with greater pressure the further away from the center of rotation.

[0507] In some embodiments, injecting air into the HTF along the radial arms 714 at an air temperature lower than the HTF temperature causes the air to heat with increasing pressure. HTF, being a fluid, is incompressible and prevents the expansion of the air, resulting in isochoric heating of the air with the flow of HTF toward the nozzles 702A, 702B.

[0508] In some embodiments, the air bubbles may reach the nozzles 702A, 702B at the same or smaller size than when injected into the arm 714.

[0509] In some embodiments, the air bubbles may arrive at the nozzles 702A, 702B at the same temperature as the HTF.

[0510] Note that as arm 714 rotates, centrifugal force is exerted on the HTF. Because fluids are typically denser than gases, and even denser than compressed gases, the HTF is pushed away from the axis of rotation, and the gas bubbles are pushed towards the axis of rotation according to Archimedes' principle.

[0511] In some embodiments, for the bubble to reach the nozzle, the drag force on the bubble due to the HTF dragging the bubble with the HTF flow must be greater than the Archimedes force pushing the bubble against the HTF flow.

[0512] In some embodiments, when the bubble is adjacent to the nozzles 702A, 702B, the bubble size may be smaller than when injected into the arm, and the Archimedes force may be lower than at the injection point.

[0513] The following parameters may typically interact in an embodiment such as that shown by FIG. 7A: centrifugal force, which depends on the distance along the arm and the rotational speed; the gas pressure of the bubbles, Arm rotation speed, the radial flow velocity of the HTF, Drag coefficient of HTF dragging bubbles with its flow Bubble size affects the drag coefficient, Bubble air mass, which together with bubble air pressure influences bubble size, the radial distance from the center of rotation to the gas injection location, and The radial position of the nozzle.

[0514] A non-limiting example calculation is given below: This example shows the nozzle at a radial distance r2, referred to herein as Position 2, where:

number

[0515] If the bubble pressure is P2 at the nozzle and P1 at the injection position, the centrifugal force F=mω 2 Due to r, P2=2*P1.

[0516] If we assume that the temperature of the air doubles while flowing between r1 and r2, the volume of the bubble remains unchanged, which corresponds to a bubble undergoing isochoric heating, V bubble_2 =V bubble_1 is.

[0517] The drag force is

number

number

[0518] The centrifugal force acting on the HTF is F cent =mω 2 r, and according to Archimedes' principle, this force acts in the opposite direction on the bubble, pushing it towards the axis of rotation, where m is the mass of the HTF displaced by the bubble and ω is the rotational velocity.

number

number

[0519] In some embodiments, the drag force of the HTF on the bubble is greater than the centrifugal force, causing the bubble to flow radially with a positive velocity.

[0520] F cent_r2 <F D_r2 which is held true for all values ​​of r between r1 and r2, including r=r2.

[0521] The following relationship is found between bubble size, HTF velocity, and further system parameters:

number

[0522] In some embodiments, the above U HTF lower than, for example, U HTF An HTF flow rate value of 50% of the saturation value is used, which still allows the bubbles to reach the nozzle but slows them down on the way.

[0523] In some embodiments, the pressure of the gas increases with the radial flow of the HTF, compressing the air with the flow, potentially reducing or eliminating the need to initially compress the inlet air used in such embodiments. Using the radial flow to compress the air can reduce the initial pressure of the compressed air, which may simplify the system and / or improve energy efficiency. In some embodiments, uncompressed gas is added to the HTF and compressed as it flows with the HTF to a location of higher pressure, such as by, but not limited to, adding gas to rotating arm 714, whose rotation pressurizes the gas as it flows outward along the rotating arm.

[0524] control

[0525] Control of the heat engines described herein is optionally provided by controlling several input parameters.

[0526] In some embodiments, the rotational speed of such a heat engine is controlled by controlling the pressure of the inlet gas, optionally by controlling a valve that controls the pressure and / or flow rate of the inlet gas.

[0527] In some embodiments, such heat engine rotation speed is optionally achieved by controlling the velocity of the incoming HTF.

[0528] In some embodiments, the rotational speed of such a heat engine is optionally achieved by controlling the size and / or shape of an adjustable nozzle.

[0529] In some embodiments, the control is optionally performed to increase the efficiency of an energy generation system that uses a heat engine as described herein.

[0530] In some embodiments, the control is optionally performed to increase the efficiency of the energy generation system, the efficiency being calculated as described elsewhere herein.

[0531] Isochoric or quasi-isochoric heating

[0532] Several embodiments of isochoric heating are described herein. However, in some embodiments, a quasi-isochoric heating process is applied even when quasi-isochoric heating is not as efficient as isochoric heating. An exemplary embodiment using a quasi-isochoric heating process may include heating a gas where some expansion occurs during heating, followed by compression of the gas. Overall, the result of the process is a hotter gas at the same or nearly the same volume, as with isochoric heating, because the gas is being heated and the final volume of the gas remains nearly the same.

[0533] The above process can be achieved with a flow of increasing pressure, which heats the gas, causing it to expand and then compress, eventually reaching the same pressure, volume, and temperature as in the isochoric heating case.

[0534] In the exemplary embodiment, the process involves isobaric heating of the gas, for example in a pipe such as rotating arm 714, followed by adiabatic compression while the gas expands.

[0535] In some embodiments, quasi-isochoric heating is achieved along a rotating pipe, such as arm 714, where centrifugal forces create increased pressure on the flowing fluid and gas mixture.

[0536] 7B, 7C, and 7D show cross-sectional side views of three exemplary embodiment configurations of nozzles associated with pools 724, 734, 744 of HTF.

[0537] Figures 7B, 7C, and 7D show nozzles 722, 732, 742 attached to mounts 721, 731, 741. In the non-limiting examples of Figures 7B, 7C, and 7D, the mounts include a pressurized air supply.

[0538] 7B, 7C, and 7D show nozzles 722, 732, 742 that provide forward thrust forces 726, 736, 746 that can be used to rotate shaft 706 of FIG. 7A and generate work.

[0539] Figures 7B and 7C show nozzles 722, 732 with heated HTF supplies 723, 733 at their front ends. In the embodiments of Figures 7B and 7C, the HTF supplied to nozzles 722, 732 is at a desired temperature for supply to nozzle 742. In some embodiments illustrated by Figures 7B and 7C, the HTF in HTF pools 724, 734 may be unheated, or the HTF may be heated as it is supplied to nozzles 722, 732. In some embodiments illustrated by Figures 7B and 7C, the HTF in HTF pools 724, 734 may be heated to a desired temperature.

[0540] Figure 7D shows a nozzle 742 moving through a pool of HTF 744. In the embodiment of Figure 7D, the HTF in the HTF pool 744 is at a desired temperature for delivery to the nozzle 742. In some embodiments, the HTF in the HTF pool 744 is heated to a desired temperature.

[0541] FIG. 7B shows a nozzle configuration in which the nozzle 722 moves above the pool 704 of HTF.

[0542] FIG. 7C shows a nozzle configuration in which nozzle 732 is above the surface of pool 704 of HTF.

[0543] FIG. 7D shows a nozzle configuration in which the nozzle 742 is immersed in a pool 704 of HTF.

[0544] 7C and 7D show nozzles 732, 742 with HTFs flowing 734, 744 directly into HTF pool 704. FIG. 7B shows nozzle 722 ejecting HTFs 724 into the air, where they fall into HTF pool 704.

[0545] In some embodiments, fins 735, 745 or baffles 735, 745 are placed in the HTF pool to rotate the flow 734 exiting the nozzles 732, 742 in a manner similar to the flow in the cup of a Pelton turbine. Such fins reduce the velocity of the HTF in the HTF pool 704, potentially providing resistance to the HTF exit 734, 744 from the nozzles 732, 742 and potentially increasing the forward thrust 736, 746 provided by the nozzles 732, 742, potentially increasing efficiency. In some embodiments, the fins 735, 745 are optionally designed to interrupt the mixing flow of the HTF flow lines 737, 747 to eliminate circulating flow of the HTF in the pool. Eliminating such flow in the pool can reduce drag on the nozzles 742 operating in the HTF pool 744.

[0546] In some embodiments, the HTF in the HTF pool is oil, molten salt, or other fluid at high temperature and ambient pressure, for example, 670 K. In some embodiments, the HTF is exchanged or reheated when its temperature drops below a certain temperature.

[0547] In such a nozzle, increased airflow increases power.

[0548] In some embodiments, such as that shown in Figure 7D, the nozzle velocity in the HTF pool is 10-50 meters per second. As the nozzle velocity increases, power increases until drag limits efficiency.

[0549] In some embodiments, the initial pressure of the injected air 721 is greater than 2 bar, optionally greater than 10 bar, 20 bar, or 40 bar. One parameter relevant to a nozzle engine is the air flow in grams per second. Typical values ​​are 20-40 grams per second for a 2 kW power engine. Increasing the air flow increases thrust (power). A 20 kW engine can be implemented by injecting a 400 gram per second air supply into a single nozzle rotating at a speed of 20 meters per second. The air flow velocity within the nozzle is typically less than 0.3% of the mass of the HTF, and after decompression, the air typically has a volume less than 70% of the volume of the air and HTF. Note that increasing the inlet area increases the nozzle thrust.

[0550] A potential problem with a configuration such as that shown in Figure 7D, where the nozzle is immersed in HTF, is drag, which can reduce engine efficiency by 50%. In some embodiments, drag is optionally reduced by reducing rotational speed.

[0551] In some embodiments, drag is reduced by placing the nozzle mostly outside the HTF, with only the nozzle outlet touching the surface of the HTF, as shown in Figure 7C. When the nozzle is outside the HTF, the nozzle inlet is connected to a pipe that supplies the HTF, and the nozzle also has a pipe that supplies air.

[0552] In some embodiments, the air supply and / or HTF supply pipes are connected to the nozzle along or through a bar that connects to the axis of rotational symmetry of the nozzle engine.

[0553] Flow direction molding

[0554] In some embodiments, the flow direction shape of a rotating arm, such as rotating arm 714 shown in FIG. 7A, is optionally non-linear.

[0555] In some embodiments, centrifugal and / or Coriolis forces are optionally taken into account when determining the shape of the rotating horizontal pipe.

[0556] Some considerations that can be taken into account are: Preventing cavitation of gas-fluid mixtures; Forces acting on the HTF cause it to separate from the pipe wall; Friction losses caused by fluid friction with the pipe wall, and Maintaining a mixture of gas and fluid and / or preventing bubbles from growing and causing the gas to separate from the fluid and / or preventing bubbles from moving in a direction different from the fluid.

[0557] In some embodiments, the shape of the pipe resembles the path of a ball being thrown radially outward from the center of a rotating carousel towards the edge of the carousel.

[0558] In some embodiments, the geometry of the pipe is designed to reduce the radial velocity of the gas and fluid mixture, which in some embodiments may even reach purely tangential flow at the circumferential ends of the pipe.

[0559] It should be noted that if the gas and fluid mixture flows tangentially when it reaches the nozzle end of the pipe, the gas bubbles may "float" in a direction opposite to the direction of centrifugal force or tangential to the flow of the HTF, potentially separating the gas from the HTF and potentially reducing engine efficiency. In some embodiments, to prevent the gas from separating from the fluid, fins are optionally added to the interior of the pipe and positioned to rotate the flow along the direction of flow. In this way, the gas bubbles are optionally maintained in a uniform mixture with the HTF.

[0560] Reference is now made to Figure 8A, which is a simplified illustration of a multiple jet engine-like configuration of an apparatus in accordance with an illustrative embodiment.

[0561] Figure 8A shows a reaction device 800 having two nozzles 802 and two curved or S-shaped arms 814. Figure 8A also shows a gas or air input 807 that directs air or gas into a pipe 806 that feeds the air or gas into a mixing chamber 808.

[0562] The curved arm 814 receives a fluid input through a fluid inlet 812 in a tank or container 816. The curved arm 814 rotates on a bearing 810.

[0563] In some embodiments, the curved arms 814 are optionally designed and / or shaped to reduce the radial velocity of the gas and fluid mixture, which in some embodiments may even amount to a purely tangential flow at the nozzle 802.

[0564] In some embodiments, the curved arms 814 are optionally designed and / or shaped to reduce and / or eliminate cavitation during mixing of the gas and fluid and / or flow of the mixture.

[0565] In some embodiments, tank or container 816 may optionally be provided with a vent 818. Vent 818 may be used to direct heated gases from container 816 to serve as a heat source for an optional further or second heat engine (not shown) to recover energy from residual heat from the heat engine of FIG.

[0566] In some embodiments, the second heat engine is optionally of the same type as the heat engine of FIG. 8A, optionally operating at different temperature and / or pressure settings.

[0567] Reference is now made to Figures 8B and 8C, which are simplified diagrams of a reaction device according to an illustrative embodiment.

[0568] FIG. 8B is an isometric view and FIG. 8C is a cross-sectional view from above.

[0569] 8B and 8C show an embodiment of a rotor 830 with four nozzles 834. The rotor 830 has an air inlet port 832, an HTF inlet port (not shown), and the cross-sectional view of FIG. 8C also shows the swirl flow path of the gas and fluid mixture from the center of the rotor 830 to the nozzles 834.

[0570] An engine that combines reaction and impulse

[0571] Reaction nozzles such as those shown in Figures 7A-7D (where the nozzle is accelerated by the reaction of the gas and fluid jets) and impulse turbines such as those shown in Figures 5 and 6 can optionally potentially increase efficiency. The gas and fluid jets emerging from the nozzles shown in Figures 7A-7D may have non-zero velocity relative to the outside world, meaning that there is residual energy in the gas and fluid jets that can be recovered.

[0572] In some embodiments, a further impulse engine, such as a Pelton wheel as shown in Figure 5 or Figure 6, can be used to convert this residual kinetic energy into work or electricity.

[0573] In some embodiments, such a secondary impulse engine or Pelton wheel implementation may be a ring around the reaction nozzle, which is also rotatable and rotated by the ejection of the gas-fluid mixture. In some embodiments, the ring may optionally have the same center of rotation as the arms of the reaction turbine.

[0574] Reference is now made to Figure 9, which is a simplified diagram of a combined reaction and impulse heat engine in accordance with an illustrative embodiment.

[0575] Figure 9 is a top view of a heat engine 900 with two reaction nozzles 902 attached to two rotating arms 914 that rotate in a first direction 906 and eject a gas and fluid mixture 903. Figure 9 also shows a ring 916 and fins or cups 904 that capture the ejected gas and fluid mixture 903 and slow the velocity of the ejected gas and fluid mixture 903, in some cases further slowing the velocity of the ejected gas and fluid mixture 903 to zero, with the ring 916 rotating in a second direction 908 opposite the first direction 906.

[0576] In some embodiments, the rotating arm 914 rotates to generate work or electricity for one energy harvester (not shown), and the rotating ring 916 rotates to generate work or electricity for another energy harvester (not shown).

[0577] In some embodiments, the rotating arm 914 and rotating ring 916 are mechanically connected to rotate and generate work or electricity for an energy harvester (not shown).

[0578] FIG. 9 shows an optional gear 910 connecting a rotating arm 914 and a rotating ring 916 for rotary motion to generate work or electricity.

[0579] In some embodiments, the ring rotates at half the rotational speed of the rotating arms, which may provide optimal efficiency in capturing rotational motion to generate work or electricity.

[0580] In some embodiments, the outer ring may optionally include fins in a configuration similar to a Tesla turbine, potentially resisting cavitation. Instead of cups, a dense array of fins, blades, or plates is positioned along the ring. Jets of ejected gas and fluid optionally flow between the blades, causing the ring to rotate due to viscous and / or adhesive forces.

[0581] The HTF engine described herein potentially has excellent efficiency at low temperatures, making it potentially very suitable for obtaining power from waste heat.

[0582] As a non-limiting example, an HTF engine could potentially be combined (secondary) cycle with a conventional generator such as a gas turbine to use its waste heat, thereby increasing the total power available.

[0583] As a non-limiting example, exhaust gases from electrical generators, which may run on gasoline, hydrogen, gas, or diesel, for example, have temperatures in excess of 300°C suitable for use in the HTF engines described herein with efficiencies in excess of 30%.

[0584] The use of clean air as the compressed gas in the heat engines described herein may limit the maximum operating temperature of the thermal oil, optionally used as the HTF, to less than 300°C to avoid spontaneous ignition of the thermal oil HTF and the clean air. This may limit engine efficiency. The exhaust gases may have a low oxygen content.

[0585] In some embodiments, the exhaust gases can optionally be used for one or more heating purposes and can be compressed gases to improve efficiency.

[0586] In some embodiments, the exhaust gases heat the oil HTF, thereby losing heat, cooling, and being compressed by the compressor. Optionally, the exhaust gases may be adiabatically compressed, raising their temperature again, and as the temperature increases, the temperature and expansion efficiency of the HTF increases.

[0587] In some embodiments, the compressor optionally mixes the gas with water, which extracts the heat generated by the compression and maintains the temperature of the gas equal to the temperature of the water, making the compression in the presence of water an isothermal compression.

[0588] The low oxygen content in the exhaust gas may allow the oil to be used while avoiding spontaneous combustion at high temperatures such as 300C, 350C, or 400C, depending on the oxygen concentration in the exhaust gas.

[0589] It should be noted that the heat engines or nozzles or turbines described in Figures 5, 6, 7, 8A-8C, 9, and 10 can also operate at ambient temperature and convert gas or air pressure to kinetic energy through the isothermal expansion of the gas or air. Such conversion can be useful in converting energy stored in the form of pressurized air into work in a continuous process.

[0590] Continuous isothermal compression of gases

[0591] The embodiments described below provide continuous isothermal or quasi-isothermal compression of gas, potentially eliminating the need for a compressed air chamber.

[0592] Several embodiments of isothermal compression of gases are described herein.

[0593] However, in some embodiments, a quasi-isothermal compression process is applied. An exemplary embodiment using a quasi-isothermal compression process involves mixing a cooler gas with a hotter fluid, causing the fluid to heat the gas, followed by further compression of the gas. Overall, the temperature of the gas equalizes with the temperature of the fluid, and then the fluid pressure further compresses the gas, and the final pressure of the gas can be higher than that achieved by, for example, isochoric heating, and approach isothermal compression.

[0594] Reference is now made to FIG. 10A, which is a simplified diagram of an apparatus for continuous isothermal compression of a gas, according to an illustrative embodiment.

[0595] FIG. 10A shows an apparatus 1000 that includes a tank or container 1002 divided into a lower portion 1004 and an upper portion 1006 by a divider 1005 .

[0596] One or more nozzles 1016 are attached to an arm 1014. The arm 1014 is designed to rotate, similar to the arms shown in Figures 7A-7D, 8A-8C, and 9.

[0597] As the arm 1014 and nozzle 1016 rotate, optionally by a mechanical shaft or electric motor (not shown), centrifugal force acts on the fluid within the arm, pushing the fluid towards and out 1022 of the nozzle 1016. The movement of the fluid creates a suction 1024 that draws more fluid 1010 from the lower portion 1004. As the arm rotates, the fluid 1010 is sucked or forced into the upper portion 1006. When the fluid 1010 is added to the upper portion 1006, the air or gas is compressed, increasing the pressure at the top of the container 1002.

[0598] Compressed gas or air can be used, for example, by drawing it through a pipe 1028 which may or may not be equipped with a pressure valve.

[0599] In some embodiments, additional gas or air for continued compression can be supplied to the upper portion 1006 (not shown) through a one-way valve that allows the gas or air to enter the upper portion 1006.

[0600] In some embodiments, additional gas or air for continued compression can be supplied 1018 to the rotating arm 1014 through a pipe 1020. The rotation of the arm 1014 and the discharge 1022 of fluid from the nozzle 1016 optionally draws in additional gas or air, and centrifugal force causes the incoming gas or air to compress even while within the arm 1014.

[0601] Supplying gas or air to the fluid in the rotating arm may increase the force with which the compressed gas and fluid mixture is expelled 1022 from the nozzle 1016. Increasing the force with which the compressed gas and fluid mixture is expelled 1022 from the nozzle 1016 may potentially reduce the force required to rotate the arm 1014, resulting in increased energy efficiency of the device 1000 by requiring less force for the same or higher compression pressure.

[0602] In some embodiments, the float valve 1008 allows fluid accumulating in the upper portion 1006 to flow back into the lower portion 1004 so that it does not accumulate in the upper portion 1006, without releasing compressed gas.

[0603] In some embodiments, the lower portion 1004 is at ambient pressure. Figure 10A shows an optional opening 1012 that allows for equalization of pressure between the lower portion 1004 and the exterior of the container 1002.

[0604] In some embodiments, a motor or machine shaft (not shown) rotates the arm 1014 and nozzle 1016, creating centrifugal force that draws in the fluid 1010. At the top elevation of the vertical (axial) pipe 1026, the pressure is lower than ambient pressure, allowing gas at ambient pressure to enter the pipe at an optionally controlled rate. In some embodiments, the gas flow rate is controlled to be sufficiently small compared to the fluid flow rate to maintain a gas discontinuity in the rotating arm 1014 to maintain centrifugal pressure on the liquid. Pressure increases with radial distance from the center of rotation.

[0605] In some embodiments, the flow rate of the fluid 1010 is optionally greater than 20% of the flow rate of the gas. While centrifugal force compresses the gas, the temperature of the fluid optionally equals the temperature of the gas. Fluids typically have a much greater heat capacity than gases, and therefore the gas assumes the temperature of the fluid.

[0606] In some embodiments, the fluid is at a higher temperature than the gas or air, and the increase in temperature increases the pressure of the gas or air.

[0607] The rotational speed and the distance of the nozzle 1016 from the center increases the output pressure of the gas from the nozzle due to centrifugal force.

[0608] Compressed air collects in the upper part 1006 of the container 1002 and potentially exits continuously through a pressure valve, while fluid returns to the lower part 1004 through a float valve 1008 and is again sucked back into the nozzle 1014.

[0609] In some embodiments, such a device can be a shaft connected to a heat engine such as those shown in Figures 7A-7D, 8A-8C, and 9 to provide compressed gas, so that a portion of the energy generated by the heat engine can provide power for the compression of gas or air in the heat engine.

[0610] A similar arrangement can be implemented in which each of the nozzles is fitted with a compressed air chamber from which compressed gas or air is drawn.

[0611] Reference is now made to FIG. 10B, which is a simplified diagram of an apparatus for continuous isothermal compression of a gas, according to an illustrative embodiment.

[0612] FIG. 10B is a variation of the exemplary embodiment of FIG. 10A.

[0613] Figure 10B shows an apparatus 1040 including a tank or container 1042 with one or more engines or nozzles 1056 attached to an arm 1044. The arm 1044 is designed to rotate, similar to the arms or rotors shown in Figures 7A-7D, 8A-8C, 9, and 10A.

[0614] As the arm 1044 and nozzle 1056 rotate, optionally by a mechanical shaft or electric motor (not shown), centrifugal force acts on the fluid within the arm, pushing the fluid towards and out 1062 of the nozzle 1056. The movement of the fluid creates suction 1060, 1064 that draws the fluid 1050 from the container 1042. As the arm rotates, the fluid 1050 is sucked or forced into the arm 1044, and gas or air 1060 is also drawn into the arm 1044. The air or gas 1060 compresses, increasing the pressure in a pressure chamber 1057 attached to the outlet of the nozzle 1056.

[0615] The compressed gas or air in the pressure chamber 1057 can be used, for example, by drawing it through a pipe 1064 leading to the pressure chamber 1057 and supplying 1070 the compressed gas or air at the outlet of the device 1040, which may or may not have a pressure valve.

[0616] In some embodiments, valve 1058 allows fluid accumulating in pressure chamber 1057 to flow back into container 1042 so that it does not accumulate in pressure chamber 1057 .

[0617] In some embodiments, the container 1042 is at ambient pressure. Figure 10B shows an optional opening 1052 that allows the pressure in the container 1042 to equalize with the outside of the container 1042.

[0618] Figures 7A-7D, 8A-8C and 9 show heat engines that optionally accept compressed gas or air input, and Figures 10A and 10B show compressed air generators.

[0619] A heat engine can be combined with a compressed air generator.

[0620] Reference is now made to Figure 11, which is a simplified diagram of an energy generation system using a combination heat engine and compressed air generator in accordance with an illustrative embodiment.

[0621] FIG. 11 shows a system 1100 that includes a compressed air generator 1102 and a heat engine 1104 .

[0622] The compressed air generator 1102 of Figure 11 includes a first container 1106 with one or more nozzles 1108 on a rotating arm 1110 that draws 1112 fluid 1114 from the first container 1106, sucks 1116 gas or air, and sprays 1118 a mixture of gas and fluid into the first container 1106. This process increases the pressure within the first container 1106.

[0623] Compressed gas flows from the compressed air generator 1102 to the heat engine 1104 through a connecting pipe 1120 .

[0624] In some embodiments, an optional pressure valve 1122 maintains a certain pressure within the first container 1106 for the supply of gas to the heat engine 1104 .

[0625] The heat engine 1104 includes a second container 1124 with one or more nozzles 1126 on a rotating arm 1128. As the arm 1128 rotates, the heat engine pumps 1130 fluid 1132 from the second container 1124 and receives compressed gas or air into the arm 1128 via pipe 1120. The rotation ejects 1134 a mixture of gas and fluid through the nozzle 1126, creating a reaction that rotates the arm 1128 and produces work or energy.

[0626] In some embodiments, the heat engine 1104 powers the compressed air generator 1102 via a mechanical link, such as, by way of non-limiting example, a chain 1136. In some embodiments, the mechanical link may include one or more shafts or gears.

[0627] In some embodiments, the heat engine 1104 is optionally vented 1138 to prevent pressure buildup during operation of the heat engine 1104 .

[0628] In some embodiments, a potentially continuously operating heat engine with heat recovery is provided: A gas such as air, nitrogen, or exhaust gas is continuously isothermally compressed, optionally at room temperature.

[0629] In some embodiments, the gas is optionally isochorically heated before entering the turbine of an isothermal expansion system that acts as a heat engine.

[0630] In some embodiments, room temperature gas is injected and then isochorically heated with flow in a horizontally rotating pipe by centrifugal force.

[0631] In some embodiments, the isothermal expansion of the gas in the nozzle rotates both the isothermal compression unit and the electric motor. The gas exits the nozzle at an elevated temperature and ambient pressure.

[0632] In some embodiments, the heat exchanger optionally extracts heat for isochoric heating of the cryogenic air input, which optionally heats the cryogenic air as the gas expands and is subsequently compressed by the centrifugal force of the rotating HTF.

[0633] In some embodiments, quasi-isochoric compression may be used, for example, isobaric heating of cryogenic air followed by centrifugal adiabatic compression of the HTF, but this may be less efficient than isochoric heating.

[0634] In some embodiments, two combined systems such as those shown in Figures 10A-10B, 11, and 12 are optionally used for continuous charging of a pressure battery and / or continuous discharging of a pressure battery.

[0635] In some embodiments, electricity powers a gas compression unit such as that shown in FIGS. 10A-10B and 11.

[0636] In some embodiments, the heat drives a heat engine described herein, for example, heat engine 1104 of Figure 11, for continuous isothermal compression of gas or air in a pressure tank. The compressed gas or air is optionally later used for continuous discharge in a continuous isothermal expansion unit to generate energy using a heat engine, such as heat engine 1104 of Figure 11.

[0637] In some embodiments, the isothermal expansion of the gas can be carried out at ambient temperature, optionally mixed with water, to convert pressure into electricity.

[0638] In some embodiments, the water is heated, which increases the expansion and the amount of energy extracted, for example in the form of electricity.

[0639] In some embodiments, high temperature HTF is optionally used to generate electricity from both pressure and heat in a continuous mode.

[0640] Reference is now made to Figures 12A and 12B, which are photographs of a water jet with and without added air or gas according to an exemplary embodiment.

[0641] Figure 12B shows how air pressure is converted into kinetic energy.

[0642] The efficiency of the process of extracting energy from a mixture of air or gas and water is calculated as the ratio of the additional energy of the water jet emerging from the nozzle to the isothermal energy of the compressed air. The calculation compares the values ​​at the inlet to the experimental setup with those at the outlet from the nozzle as follows:

number

[0643] Experiments using the nozzle showed efficiencies of over 80% due to the isothermal expansion of gas in water.

[0644] A comparison was made of the load on a load cell connected to a nozzle operated by a flow of HTF only, compared to a flow of HTF with gas or bubbles, at pressures up to 3 bar and gas velocities up to 10 g / sec.

[0645] Figure 12A shows a first water jet 1202 emerging from a nozzle, and Figure 12B shows a second gas and water jet 1204 emerging from the same nozzle, with 10 g / sec of air added to the water at a pressure of 2 bar.

[0646] The distance and height reached by the jets 1202, 1204 indicates that the second jet 1204 has more energy than the first jet 1202.

[0647] Reference is now made to FIG. 13, which is a simplified flowchart of a method according to an exemplary embodiment.

[0648] The method of the exemplary embodiment of FIG. 13 is a method for converting heat to mechanical work, comprising: Providing (1302) an inlet heat transfer fluid (HTF) at a first temperature to a mixing chamber; providing (1304) an inlet compressed gas at a second temperature to the mixing chamber; allowing the gas and the HTF to mix (1306), producing a gas and HTF mixture; allowing the HTF in the gas-HTF mixture to heat the gas and allow the gas in the gas-HTF mixture to expand isothermally (1308); restricting the volume of HTF in the gas and HTF mixture, thereby increasing the pressure of the gas and accelerating the flow of the gas and HTF mixture (1310); ejecting the gas and HTF mixture through a nozzle, thereby converting the heat of the HTF into kinetic energy (1312); Using kinetic energy to produce mechanical work (1314); The method includes:

[0649] Reference is now made to Figure 14, which is a simplified diagram of a system according to an exemplary embodiment.

[0650] The system of Figure 14 includes the energy generating components described herein and additional optional components.

[0651] FIG. 14 shows a heat engine 1402 powering a generator 1408 .

[0652] In some embodiments, the heat engine 1402 may power a compressor 1406 that provides compressed air or gas to the heat engine 1402 .

[0653] In some embodiments, a generator 1408 may power a compressor 1406 that provides compressed air or gas to the heat engine 1402 .

[0654] In some embodiments, a heated fluid is provided 1405 to operate the heat engine 1402. The fluid is heated by a heat source 1412 such as solar heat, geothermal heat, waste heat from power plants, heat from coolants used to cool nuclear power plants, heat from coolants used to cool fossil fuel power plants, combustion of fossil fuels, heat from industrial applications such as cement manufacturing, endothermic chemical reactions, as some non-limiting examples.

[0655] In some embodiments, the heated fluid can optionally be stored in an optional input reservoir 1404 .

[0656] In some embodiments, hot gas or air from the heat engine 1402 can optionally be used to heat a fluid in a preheat reservoir 1410 that potentially captures heat exiting the heat engine 1402, and optionally uses that heat to preheat a fluid intended for use in operating the heat engine 1402.

[0657] In some embodiments, isochoric heating of compressed air occurs in a heat engine 1402. Mechanical energy is generated as the heated air reaches a nozzle in the heat engine and undergoes rotational motion.

[0658] In some embodiments, some of the mechanical energy is used to drive a compressor 1406, optionally via a mechanical shaft or belt or chain drive, and additional mechanical energy is used to power a generator 1408.

[0659] In some embodiments, the generator may also be driven via a mechanical shaft or belt or chain drive.

[0660] In some embodiments, air is used as the gas to be compressed and molten salt is used as the heat transfer fluid, for example at a temperature of 550 degrees Celsius. The hot air emerging from the nozzle may be at near ambient pressure but still hot, for example at a temperature near 550 degrees Celsius, and can optionally be directed to a preheat reservoir 1410 for heat reuse.

[0661] In some embodiments, the exiting hot air can optionally drive a second heat engine (not shown), which in some embodiments is at a lower temperature.

[0662] The system shown in Figure 14 is expected to operate with an efficiency η>40%, calculated as described in the equation above.

[0663] It is expected that many related heat engines will be developed between the filing of this application and the expiration of the patent term, and the scope of the term heat engine is intended to proactively include all such new technologies.

[0664] The term "about" when used herein in reference to an amount or value means "within ±75% of."

[0665] The terms comprise, include, and have and their conjugations mean "including, but not limited to."

[0666] The term "consisting of" is intended to mean "including and limited to."

[0667] The term "consisting essentially of" means that a composition, method, or structure may include additional ingredients, steps, and / or moieties, provided that the additional ingredients, steps, and / or moieties do not materially alter the basic and novel characteristics of the claimed composition, method, or structure.

[0668] As used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. For example, the terms "a unit" or "at least one unit" can include plural units, including combinations thereof.

[0669] The words "example" and "exemplary" are used herein to mean "serving as an example, instance, or illustration." An embodiment described as "example" or "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments and / or as excluding the incorporation of features from other embodiments.

[0670] The word "optionally" is used herein to mean "provided in some embodiments and not provided in other embodiments." Any particular embodiment of the present disclosure may include multiple "optional" features unless such features are inconsistent.

[0671] Throughout this application, various embodiments of the present disclosure may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the present disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all possible subranges as well as individual numerical values ​​within that range. For example, the description of a range such as 1 to 6 should be considered to have specifically disclosed subranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, etc., as well as individual numerical values ​​within that range, e.g., 1, 2, 3, 4, 5, and 6. This is true regardless of the breadth of the range.

[0672] Whenever a numerical range is given herein (e.g., "10-15," "10 to 15," or any pair of numerical values ​​linked by these or other such range designations), it is meant to include any numerical value (fractional or integer) within the stated range limits, inclusive of the upper and lower limits of the range, unless the context clearly dictates otherwise. The phrases "range between a first recited number and a second recited number," and "range from a first recited number to a second recited number" (or other such range terminology) are used interchangeably herein and are meant to include the first recited number and the second recited number, and all fractional and integer numbers therebetween.

[0673] Unless otherwise specified, the numerical values ​​used herein and any numerical ranges based thereon are approximations within reasonable measurement precision and rounding errors understood by one of ordinary skill in the art.

[0674] It should be understood that certain features of the present disclosure that are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the present disclosure that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or with any other described embodiment of the present disclosure, as appropriate. Certain features described in the context of various embodiments should not be considered essential features of those embodiments, unless the embodiment cannot function without those elements.

[0675] While this disclosure has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims.

[0676] It is the intention of the applicants that all publications, patents, and patent applications referenced herein be incorporated by reference in their entirety, as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference herein. Furthermore, citation or identification of any reference in this application should not be construed as an admission that such reference is available as prior art to the present invention. To the extent section headings are used, they should not be construed as necessarily limiting. Additionally, the priority documents of this application are incorporated herein by reference in their entirety.

Claims

1. 1. A method for converting heat to mechanical work, comprising: providing an inlet heat transfer fluid (HTF) at a first temperature to a mixing chamber; supplying an inlet compressed gas at a second temperature to the mixing chamber; allowing the gas and the HTF to mix to produce a gas and HTF mixture; allowing the gas to expand while heating it in the HTF, thereby obtaining an isothermal expansion of the gas in the mixture of the gas and the HTF; restricting the volume of the gas and HTF mixture, thereby accelerating the flow of the gas and HTF mixture; ejecting the mixture of gas and HTF from a nozzle, thereby converting heat of the HTF into kinetic energy; using the kinetic energy to generate mechanical work; wherein the HTF is a liquid; Providing the inlet gas, providing the inlet HTF, and allowing the mixture of the gas and HTF to flow through a nozzle comprises: providing an input gas to a plurality of mixing chambers; providing an influent HTF to said plurality of mixing chambers; allowing the gas and HTF mixture to flow through a plurality of nozzles; generating work using the motion of the plurality of nozzles; A method comprising:

2. The method of claim 1 , wherein the mechanical work is used to drive an electrical generator.

3. The method of claim 1 , wherein the mechanical work is used to drive a compressor for compressing the incoming compressed gas.

4. The method of claim 1 , wherein the first temperature of the inflow HTF is greater than 90 degrees Celsius.

5. The method of claim 1 , wherein the second temperature of the inlet gas is less than the first temperature.

6. The method of claim 1 , wherein the gas is quasi-isochorically heated by the HTF.

7. The method of claim 1 , wherein the gas is isochorically heated by the HTF.

8. The generation of kinetic energy is the pressure of the incoming compressed gas; the flow rate of the inlet gas, flow rate of the influent HTF; the size of the nozzle, and The shape of the nozzle; 10. The method of claim 1, wherein the temperature is controlled by controlling a parameter selected from the group consisting of:

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