Two-phase heat engine

Abstract

The present disclosure provides systems and methods for generating work. The system and method provide for a unique implementation of an Ericsson cycle. In the solution of the present disclosure, the HTL is mixed with the gas, and the HTL and the gas reach approximately the same temperature after their mixing. The HTL and the gas are mixed at approximately the same pressure and together undergo expansion in the nozzle as a mixture from a first pressure to a second pressure lower than the first pressure. Since the HTL has a much higher heat capacity and the gas is surrounded by the HTL during expansion, the HTL continuously heats the gas during expansion, which results in isothermal or quasi-isothermal expansion in the nozzle. The expansion of the gas causes the mixture within the nozzle to accelerate and converts the kinetic energy of the accelerated mixture into work by using the nozzle in a reaction turbine or by driving a turbine, such as an impulsive turbine, using the injected mixture. When the invention is implemented in a reaction turbine, a non-zero velocity HTL / gas mixture at the outlet of the nozzle is used to separate the mixture by creating a membrane flow on a circular frame and the membrane flow being subjected to the centrifugal force of the frame. The injected gas is cooled in a heat exchanger, such as a regenerator, and is re-compressed while it is cooled in the compressor. The compressed gas is then heated in a heat exchanger (regenerator) before returning to the turbine. The injected HTL is collected to undergo another cycle in the turbine. A portion of the HTL is reheated by passing through an additional heat exchanger with a heat source.

Description

Technical Field

[0001] This disclosure pertains to the field of heat engines, and particularly to the field of heat engines based on mixtures of two materials in different phases. Background Technology

[0002] The following list of references is considered relevant to the currently published topic as background information:

[0003] -WO 2022 / 049573.

[0004] The acknowledgment of the above references in this document should not be construed as implying that these references are related in any way to the patentability of the currently disclosed subject matter. Summary of the Invention

[0005] This disclosure provides systems and methods for generating work. These systems and methods offer a unique implementation of the Ericsson cycle. In the solution of this disclosure, the HTL is mixed with a gas, and the HTL and gas reach the same temperature after mixing. The HTL and gas are mixed at approximately the same pressure, and the HTL and gas, as a mixture, undergo expansion together in a nozzle from a first pressure to a second pressure lower than the first pressure. Because the HTL has a much higher heat capacity, and the gas is surrounded by the HTL during expansion, the HTL continuously heats the gas during expansion, resulting in isothermal or quasi-isothermal expansion in the nozzle. The expansion of the gas causes the mixture within the nozzle to accelerate, and the kinetic energy of the accelerated mixture is converted into work by using the nozzle in a reaction turbine or by using the injected mixture to drive a turbine, such as an impulse turbine. Due to its efficiency, the solution of this invention is more suitable for use in reaction turbines. Reaction turbines achieve high static pressure with minimal head loss. Furthermore, in a reaction turbine, the non-zero velocity HTL / gas mixture at the nozzle exit is used to separate the mixture by forming a film flow on a circular frame, which is then subjected to centrifugal force by the frame. Finally, the reaction turbine avoids the cavitation phenomenon that occurs in impulse turbines. The injected gas is cooled in a heat exchanger, such as a regenerator, and is recompressed while being cooled in a compressor. Optionally, the compression in the compressor is isothermal or quasi-isothermal. The compressed gas is then heated in a heat exchanger (regenerator) before returning to the turbine. The injected HTL is collected to undergo another cycle in the turbine. A portion of the HTL is reheated by passing through an additional heat exchanger with a heat source.

[0006] Therefore, a first aspect of this disclosure provides a method for generating work. The method includes heating a heat transfer liquid (HTL) to a first temperature within a heating volume and delivering the HTL to the inlet of a nozzle at approximately a first pressure. The method also includes compressing a gas to approximately the first pressure using a compressor and heating the compressed gas to approximately the first temperature or below approximately the first temperature but above approximately the second temperature, i.e., a temperature between approximately the second temperature and approximately the first temperature, within a heat receiving section of a heat exchanger. The term "approximately" should be interpreted as a deviation of up to 20%. For example, if a first material is compressed to the pressure of a second material, this can be interpreted as a deviation of the nominal pressure values ​​of the first and second materials within 20%. The same applies to temperature. It should be noted that, in the context of an implementation of the method or system of this disclosure, since the heat-transferring gas is at the first temperature, it is not possible to heat the gas above the first temperature simply by receiving heat from the heat exchanger. The method also includes mixing the HTL at the first pressure and the first temperature with the compressed gas at approximately the first pressure and approximately the first temperature or below approximately the first temperature in the nozzle to obtain a mixture of gas and HTL. It should be noted that the gas can be mixed with the HTL when its temperature is below approximately the first temperature. Therefore, after the mixing, if the gas temperature is below approximately the first temperature, the gas is heated by the HTL to approximately the first temperature. The method also includes allowing the gas in the mixture to undergo isothermal or quasi-isothermal expansion within the nozzle to reach a second pressure lower than the first pressure, thereby accelerating the mixture toward the outlet of the nozzle. The method further includes: injecting the mixture through the outlet to generate mechanical work to separate the mixture; introducing the injected gas into the deheating section of the heat exchanger to exchange heat with the compressed gas leaving the compressor; and guiding the injected HTL toward the heating volume to undergo another cycle.

[0007] In some embodiments of the method, the compression includes isothermal or pseudo-isothermal compression of the gas.

[0008] Another aspect of this disclosure provides a method for implementing a heat engine. The method includes: (i) introducing a heat transfer liquid (HTL) at a first pressure and a first temperature into a nozzle; (ii) isothermally compressing a gas from a second pressure and a second temperature to the first pressure using a compressor, wherein the second pressure and the second temperature are respectively lower than the first pressure and the first temperature; (iii) heating the compressed gas exiting the isothermal compressor at the first pressure and the second temperature to about the first temperature or below about the first temperature but above about the second temperature by passing the compressed gas, which exits the isothermal compressor at the first pressure and the second temperature, through a heat receiving section of a counter-current heat exchanger; (iv) injecting the heated gas exiting the heat receiving section of the heat exchanger into the nozzle to obtain a mixture of HTL and gas, thereby causing the mixture to expand isothermally or quasi-isothermally to the second pressure, resulting in acceleration of the mixture in the nozzle; (v) ejecting the accelerated mixture from the outlet of the nozzle; and (vi) recovering the ejected gas at about the second pressure and about the first temperature to a deheating section of the heat exchanger to exchange heat with the compressed gas exiting the compressor.

[0009] In some embodiments of the method, the gas introduced into the heat exchanger after being injected from the nozzle is repeatedly isothermally or quasi-isothermally compressed, thereby forming a closed-loop flow of gas. That is, after the hot gas injected from the nozzle passes through the heat exchanger and exchanges heat with the cooler and the compressed gas leaving the compressor, the gas is guided to undergo isothermal or quasi-isothermal compression through the compressor as part of the closed-loop operation.

[0010] It should be noted that any combination of the embodiments described with respect to any aspect of this disclosure is applicable. In other words, any aspect of this disclosure can be defined by any combination of the described embodiments. In particular, any of the following embodiments of the method is applicable to any of the above method aspects.

[0011] In some embodiments of this method, delivering the HTL into the nozzle or introducing the HTL into the nozzle includes pressurizing the HTL to approximately the first pressure. After the HTL is ejected from the nozzle, the HTL is at approximately the second pressure. Therefore, in order to undergo another cycle, the HTL needs to be pressurized to approximately the first pressure. This can be accomplished by a pumping unit, or, if the method is implemented in a reaction turbine, the centrifugal force of the turbine creates an intake state and effectively forms a pump that raises the pressure of the HTL to approximately the first pressure. In some embodiments of this method, the gas entering the compressor is ambient air, and the gas leaving the heat exchanger after deheating—that is, the gas that entered the heat exchanger hot and left its cooler—is discharged to the surrounding environment.

[0012] In some embodiments of the method, HTL is selected from a list including: molten salt, hot oil, ethylene glycol, water, molten metal or any combination thereof.

[0013] In some embodiments of the method, the gas is from one of the following: air, nitrogen, argon, or any combination thereof.

[0014] In some embodiments, the method further includes monitoring the HTL temperature. The method also includes controllably releasing gas from a compressed gas reservoir storing compressed gas at approximately the first pressure and approximately the second temperature into the heat receiving section. The controllably releasing the gas is based on the HTL temperature to obtain constant output power.

[0015] In some embodiments, the method further includes monitoring the HTL temperature. The method also includes controllably releasing gas from a compressed gas reservoir storing compressed gas at approximately the first temperature and approximately the first pressure to a location in the gas flow path between the heat exchanger and a nozzle or turbine. That is, the compressed gas reservoir stores hot compressed gas at a location downstream of the heat receiving section of the heat exchanger when needed. The controllable release of the gas is based on the HTL temperature to obtain constant output power.

[0016] In some embodiments, the method further includes supplying compressed gas to a compressed gas reservoir after the compressed gas has been compressed by the compressor. This is typically done during the startup process of the method, which initially fills the compressed gas reservoir with hot or cold compressed gas for later use when needed, i.e., due to HTL temperature changes.

[0017] Specifically, when the HTL temperature drops below the desired operating temperature, this causes thermal expansion to decrease with heating, resulting in the HTL entering the nozzle at a lower volumetric flow rate and mixing with the HTL. To maintain a constant output power, additional gas needs to be added to the circulation, and this additional gas addition is performed by controlling a valve that is opened and closed controllably based on the HTL temperature.

[0018] In some embodiments of the method, the stored gas is at approximately the first pressure and approximately the second temperature. Controllable release of gas from the compressed gas reservoir occurs downstream of the heat receiving section and upstream of or at the nozzle.

[0019] In some embodiments of the method, the compressed stored gas is at approximately the second temperature, wherein the volumetric flow rate from the gas reservoir is determined according to the following formula: And among them, T HTL It is the temperature of HTL. This is the volumetric flow rate of the gas entering the nozzle, and the temperature is measured in Kelvin. In this control system, isobaric heating of the gas results in constant volume and pressure.

[0020] In some embodiments of the method, the compressed stored gas is at approximately the first pressure and approximately the first temperature. The controlled release of gas from the gas reservoir is performed at a location between the end of the heat receiving section and the nozzle, including the flow path of the nozzle.

[0021] In some embodiments, the method further includes maintaining a constant volumetric flow rate of gas in the nozzle within the range of the HTL operating temperature after the gas is heated to the HTL temperature and before the pressure is reduced.

[0022] In some embodiments, the method further includes maintaining equal static pressures at the nozzle inlet, or at a mixing region of the nozzle where the HTL is mixed with the gas, and at a proximal end portion of an outlet region in the nozzle, the outlet region being downstream of the mixing region. In some embodiments, the equal static pressures are higher than 50% of the stagnation pressure.

[0023] In some embodiments of this method, the first temperature, first pressure, second temperature, second pressure, and flow rate are within 30% of their nominal values. That is, these values ​​may deviate by up to 30%.

[0024] In some embodiments of the method, the jetting causes the nozzle to rotate, thereby generating work.

[0025] In some embodiments of the method, the nozzle is part of a reaction turbine, wherein the nozzle is a portion of the turbine located at the outer peripheral edge of the impeller, where the static pressure and stagnation pressure are highest.

[0026] In some embodiments of this method, the injection is performed at a non-zero velocity, which forms a film flow on the injected surface. The film flow on the surface leads to the separation of the gas and HTL.

[0027] In some embodiments, the method further includes separating the HTL from the gas after the injection.

[0028] In some embodiments of the method, the separation involves directing the sprayed mixture onto a curved surface. The collision or engagement of the gas and HTL mixture with the curved surface results in flow on the surface, which is subjected to centrifugal force. This leads to the separation of the HTL and the gas.

[0029] In some implementations, the method also includes retrieving a portion of the sprayed HTL back into the nozzle for another cycle.

[0030] In some embodiments of the method, the turbine is a reaction turbine, and the retraction is performed because the operation of the reaction turbine causes the HTL to be drawn into the nozzle.

[0031] In some implementations of this method, the heat exchanger is a regenerator.

[0032] In some embodiments of the method, the first pressure is higher than about 8 bar, 9 bar, 10 bar, 11 bar or 12 bar, and the first temperature is higher than about 100°C.

[0033] In some embodiments of this method, the flow of the mixture in the nozzle is a supersonic flow.

[0034] In some implementations of this method, the second pressure is environmental pressure.

[0035] In some implementations of this method, the second temperature is the ambient temperature.

[0036] Another aspect of this disclosure provides a system for generating work. The system includes a heating volume for allowing a heat transfer liquid (HTL) to be heated to a first temperature by a heat source. A pump in the system is configured to increase the pressure of the HTL to a first pressure at the first temperature. The pump can be located in various positions within the system. For example, the pump can be located downstream or upstream of the heating volume. Optionally, the inherent centrifugal force of a reaction turbine acts as a pump for at least a portion of the HTL. The at least a portion of the HTL is pumped due to the state induced by the reaction turbine and delivered from a discharge section (described below) to a nozzle, while increasing the pressure of the at least a portion of the HTL from about a second pressure to about a first pressure. If the pump formed by the reaction turbine is the only pump in the system, the system startup process requires external intervention, such as a driver that causes the system startup operation, or a pump that causes the first cycle of the system. The system also includes a compressor, such as an isothermal compressor, configured to compress the gas to about the first pressure. The system also includes a heat exchanger in fluid communication with the compressor and configured to receive compressed gas in a heat-receiving section of the heat exchanger to allow heat transfer to the compressed gas, thereby increasing the temperature of the compressed gas to about the first temperature or below about the first temperature but above about the second temperature. The system also includes a nozzle in fluid communication with the heat exchanger and the HTL pump, the nozzle having an inlet section for receiving the HTL and a mixing section for (i) allowing the HTL at about the first temperature and about the first pressure to be mixed with the gas at about the first temperature and about the first pressure to obtain a mixture, and (ii) allowing the mixture to undergo isothermal expansion to reach a second pressure lower than the first pressure, thereby accelerating the mixture at the nozzle toward the nozzle outlet. The system also includes a turbine, such as a reaction turbine connected to the nozzle or a portion of the nozzle, the turbine mechanism causing rotation due to the acceleration of the mixture, thereby converting the kinetic energy of the mixture into work. The system also includes a separation unit for separating the gas and the HTL. The separation unit includes a collection unit for collecting the injected HTL and guiding it to the inlet of a heating volume, pump, or nozzle to undergo another cycle without reheating the injected HTL. Since the volumetric heat capacity of HTL is approximately 100 times higher than that of a gas, heat transfer from HTL to the gas during isothermal expansion in the nozzle only slightly lowers the HTL temperature. Therefore, HTL can undergo multiple cycles in the nozzle before needing to be reheated.Therefore, the system can be designed to partially guide the HTL accumulated in the collection unit to the heating volume or pump according to the order of their flow path in the system. This can be varied in different implementations of the system, and a portion of the HTL is guided back to the nozzle to undergo another cycle. The injected gas is guided to the deheating section of the heat exchanger to exchange heat with the compressed gas flowing from the compressor in the heat receiving section.

[0037] In some implementations of this system, the cooling gas leaving the heat exchanger's deheating section flows to the compressor, thus forming a closed-loop gas flow.

[0038] In some embodiments of the system, cooling gas leaving the heat exchanger's deheating section flows to the surrounding environment, and a compression mechanism causes gas to be received from the surrounding environment to compress the gas to approximately the first pressure, thereby forming an open system.

[0039] In some implementations of this system, HTL is selected from the group consisting of molten salt, hot oil, molten metal, ethylene glycol, water, or any combination thereof.

[0040] In some embodiments of the system, the gas is selected from the group consisting of air, nitrogen, argon, or any combination thereof.

[0041] In some embodiments, the system further includes a compressed gas reservoir that stores compressed gas at approximately the first pressure and is in fluid communication with a portion of the flow path between the compressor and the heat receiving section. The compressed gas reservoir is configured to controllably release gas based on the sensed temperature of the HTL to obtain either (i) a constant volumetric flow rate injected into the nozzle or (ii) a constant output power.

[0042] In some embodiments, the system further includes a compressed gas reservoir that stores compressed gas at approximately the first pressure and approximately the first temperature, and is in fluid communication with a portion of the flow path between the end of the heat receiving section and the nozzle, including the nozzle. That is, the hot compressed gas from the compressed gas reservoir is in fluid communication with a portion of the flow path downstream of the heat receiving section of the heat exchanger and upstream of the nozzle, or sometimes with the nozzle itself. The gas reservoir is configured to controllably release gas based on the sensed temperature of the HTL to obtain either (i) a constant volumetric flow rate injected into the nozzle or (ii) a constant output power.

[0043] It is important to note that in some embodiments, the compressed gas reservoir is configured to be primarily filled with compressed gas compressed by the system's compressor. After the gas is compressed by the compressor, it is directed to fill the compressed gas reservoir in its hot or cold state, i.e., before or after passing through a heat exchanger. Therefore, the system startup setup may include filling the compressed gas reservoir to allow the system to operate effectively.

[0044] Specifically, when the HTL temperature drops below the desired operating temperature, this causes thermal expansion to decrease with heating, resulting in the HTL entering the nozzle at a lower volumetric flow rate and mixing with the HTL. To maintain a constant flow rate and therefore a constant output power, additional gas needs to be added to the circulation, and this additional gas addition is performed by controlling a valve that is controllably opened and closed based on the HTL temperature.

[0045] In some embodiments, the system further includes a temperature sensor configured to sense the temperature of the HTL at at least one location along the flow path of the HTL to generate HTL temperature data based on that temperature, and to transmit the HTL temperature data to a controller of the compressed gas reservoir to control a valve for performing the controlled release.

[0046] In some embodiments of this system, the temperature sensor is configured to sense the temperature of the HTL at a location along the flow path of the HTL between the HTL being injected from the nozzle and the nozzle inlet, i.e., the location where the HTL enters the nozzle. Any location along the flow path defined above is suitable for sensing the temperature of the HTL.

[0047] In some embodiments of the system, the temperature sensor is configured to sense the temperature of the HTL at at least one location along the flow path of the HTL between the injection of the HTL from the nozzle and the introduction of the HTL into the nozzle.

[0048] In some embodiments of the system, the temperature sensor is configured to sense the temperature of the HTL in the collection unit. That is, the temperature sensor senses the temperature of the HTL accumulated in the collection unit.

[0049] In some embodiments of the system, the temperature sensor is configured to sense the temperature of the HTL at the HTL discharge section that receives the HTL after it is ejected from the nozzle.

[0050] In some embodiments of the system, the compressed gas is at approximately the first pressure and approximately the second temperature. The compressed gas reservoir is in fluid communication with the heat receiving section or a portion upstream of it. That is, the compressed gas reservoir is connected to a portion of the flow path between the compressor and the heat receiving section of the heat exchanger.

[0051] In some embodiments of the system, the compressed gas is at approximately the second temperature, wherein the volumetric flow rate from the compressed gas reservoir is determined according to the following formula: Among them, T HTL It is the temperature of HTL. It is the volumetric flow rate of the gas entering the nozzle, and the temperature is measured in Kelvin.

[0052] In some embodiments of the system, the compressed gas is at approximately the first pressure and approximately the first temperature. The compressed gas reservoir is in fluid communication with the heat removal section or its downstream portion. That is, the hot compressed gas from the compressed gas reservoir is in fluid communication with a portion of the flow path downstream of the heat receiving section of the heat exchanger and upstream of the nozzle, or sometimes in fluid communication with the nozzle itself.

[0053] In some embodiments of the system, the compressed gas reservoir includes a controller configured to maintain a constant volumetric flow rate of gas in the nozzle within the range of the HTL operating temperature.

[0054] In some embodiments of the system, the nozzle is configured to maintain equal static pressure at the nozzle inlet, or at the mixing volume of the nozzle where the gas is mixed with the HTL, and at the proximal end of the outlet region located downstream of the mixing volume. In some embodiments, the equal static pressure is higher than 50% of the stagnant pressure.

[0055] In some implementations of this system, the first temperature, first pressure, second temperature, second pressure, and flow rate are within 30% of their nominal values. That is, these values ​​may deviate by up to 30%.

[0056] In some implementations of this system, the heat source is solar radiation, and the heating volume is configured to receive heat from solar radiation and transfer the heat to the HTL.

[0057] In some implementations of this system, the pump is positioned downstream of the nozzle and upstream of the heating volume.

[0058] In some implementations of this system, the pump is positioned downstream of the heating volume and upstream of the nozzle.

[0059] In some embodiments of the system, the nozzle includes the heating volume.

[0060] In some embodiments of the system, the nozzle includes a de Laval nozzle supersonic contraction-expansion section, i.e., a section defined by an asymmetric hourglass shape. The de Laval nozzle section is defined between a proximal end and a distal end, and wherein the de Laval nozzle section is defined downstream of the mixing section. An optional advantage of the supersonic de Laval nozzle compared to a subsonic nozzle is its higher efficiency and higher output power due to the high mass ratio of the gas / HTL mixture.

[0061] In some implementations of this system, the Laval nozzle has a circular geometry in its cross-section.

[0062] In some implementations of this system, the Laval nozzle cross-section has a rectangular geometry with rounded corners.

[0063] In some embodiments of this system, the proximal ends of the inlet section, mixing section, and Laval nozzle section all have approximately similar maximum cross-sectional areas. Each of these sections has a maximum cross-sectional area defined on a plane perpendicular to the flow direction, i.e., on an approximately similar maximum horizontal cross-section forming a circular shape. It should be noted that, in the context of similar cross-sections, the term "approximately" means a deviation of up to 20% from the nominal cross-sectional area. Typically, the maximum cross-section of the mixing section is slightly larger than the maximum cross-section of the inlet section due to the additional volume of the injected gas.

[0064] In some implementations of this system, the maximum cross-section of the mixing section is up to 20% larger than the maximum cross-section of the inlet section.

[0065] In some embodiments of the system, the maximum cross-section of the mixing portion is the same as the maximum cross-section of the proximal end. That is, the maximum cross-section of the mixing portion is located at its downstreammost portion where it meets the proximal end.

[0066] In some embodiments of this system, the turbine includes the nozzle, and the nozzle rotates together with the impeller to generate work. That is, the accelerated mixture is injected through the nozzle, causing the nozzle to rotate, which results in the generation of work, generating electricity through rotation.

[0067] In some implementations of this system, the turbine is a reaction turbine.

[0068] In some embodiments of the system, the collection unit defines a discharge section for accumulating the separated HTL. A portion of the HTL is drawn from the discharge section into the nozzle due to the operation of the reaction turbine, causing the HTL pressure to increase from the second pressure to the first pressure. That is, there is a pipe connection between the nozzle and the discharge section, and the mixture is drawn into the nozzle by injection, which causes the HTL pressure to increase to approximately the first pressure and results in the delivery of the HTL to the nozzle or the nozzle inlet.

[0069] In some embodiments of this system, the separation unit includes a curved or circular frame onto which the mixture is sprayed. The contact between the mixture and the curved or circular frame results in a film-like flow on the surface of the frame. The flow on the surface experiences centrifugal force exerted by the frame, which leads to HTL and gas separation.

[0070] In some implementations of this system, the heat exchanger is a regenerator.

[0071] In some implementations of this system, a portion of the reaction turbine forms the pump.

[0072] In some embodiments of this system, the pump is positioned or defined between the discharge section and the nozzle. That is, the pump is defined downstream of the discharge section and upstream of the nozzle. The centrifugal force generated by the reaction turbine creates a suction state, which effectively acts as a pump to pump the HTL from the discharge section and deliver the HTL to the nozzle while simultaneously increasing the pressure of the HTL from about the second pressure to about the first pressure.

[0073] In some implementations of the system, the first pressure is above about 8 bar, 9 bar, 10 bar, 11 bar or 12 bar, and the first temperature is above about 100°C.

[0074] In some implementations of this system, the second pressure is environmental pressure.

[0075] In some implementations of the system, the second temperature is the ambient temperature.

[0076] In some implementations of this system, the flow of the mixture in the nozzle is a supersonic flow.

[0077] Any of the above embodiments of the system, or any combination thereof, can be used in any of the above embodiments of the method, or any combination thereof.

[0078] Another aspect of this disclosure provides a nozzle for use in a heat engine. The nozzle includes: an inlet portion for receiving a heat transfer fluid; a mixing portion for mixing the received heat transfer fluid (HTL) with a gas; and a Laval nozzle portion, defined by an asymmetric hourglass shape, between a proximal end and a distal end. The Laval nozzle portion is defined downstream of the mixing portion, which is also defined downstream of the inlet portion. The Laval portion is configured to allow isothermal expansion of the gas at a pressure between a first pressure and a second pressure below the first pressure.

[0079] In some embodiments, the nozzle also includes an injection port for allowing gas to be injected into the mixing section.

[0080] In some embodiments of the nozzle, the inlet section, the mixing section, and the proximal ends of the Laval nozzle section all have approximately similar maximum cross-sectional areas, wherein each maximum cross-section is defined on a plane perpendicular to the flow direction, i.e., on an approximately similar maximum horizontal cross-section forming a circular shape. It should be noted that, in the context of similar cross-sections, the term "approximately" means a deviation of up to 20% from the nominal cross-sectional area. Typically, the maximum cross-section of the mixing section is slightly larger than the maximum cross-section of the inlet section due to the additional volume of the injected gas.

[0081] In some embodiments of the nozzle, the maximum cross-section of the mixing section is up to 20% larger than the maximum cross-section of the inlet section.

[0082] In some embodiments of the nozzle, the maximum cross-section of the mixing section is the same as the maximum cross-section of the proximal end. That is, the maximum cross-section of the mixing section is located at its downstreammost portion where it meets the proximal end.

[0083] Implementation

[0084] The following are alternative embodiments and combinations thereof based on various aspects of this disclosure:

[0085] 1. A method for generating work, the method comprising:

[0086] The heat transfer fluid (HTL) is heated to a first temperature in a heating volume and the HTL is delivered to the inlet of the nozzle under approximately a first pressure.

[0087] The gas is compressed to approximately the first pressure by a compressor, and the compressed gas is heated to approximately the first temperature or below approximately the first temperature in the heat receiving section of a heat exchanger.

[0088] In the nozzle, the HTL at the first pressure and the first temperature is mixed with a compressed gas at about the first pressure and about the first temperature or below the first temperature to obtain a mixture of gas and HTL, wherein, after the mixing, the gas and HTL in the mixture reach approximately the same temperature;

[0089] The gas in the mixture is allowed to undergo isothermal or quasi-isothermal expansion within the nozzle to reach a second pressure lower than the first pressure, thereby accelerating the mixture toward the outlet of the nozzle;

[0090] The mixture is injected through the outlet to generate mechanical work;

[0091] The injected gas is introduced into the heat exchanger's deheating section to exchange heat with the compressed gas leaving the compressor; and

[0092] At least a portion of the sprayed HTL is directed toward the heated volume.

[0093] 2. The method according to embodiment 1, wherein the compression includes isothermal or pseudo-isothermal compression of the gas.

[0094] 3. A method for realizing a heat engine, the method comprising:

[0095] Heat transfer fluid (HTL) is introduced into the nozzle at a first pressure and a first temperature;

[0096] The gas is isothermally compressed from a second pressure and a second temperature to the first pressure using a compressor, wherein the second pressure and the second temperature are lower than the first pressure and the first temperature, respectively.

[0097] The compressed gas is heated to approximately the first temperature by passing the compressed gas that leaves the isothermal compressor at the first pressure and the second temperature through the heat receiving section of the counterflow heat exchanger.

[0098] Heated gas exiting the heat receiving section of the heat exchanger is injected into the nozzle to obtain a mixture of HTL and gas, thereby causing the mixture to expand isothermally or quasi-isothermally to the second pressure, resulting in acceleration of the mixture within the nozzle; and

[0099] The accelerated mixture is ejected from the nozzle outlet;

[0100] The injected gas, at approximately a second pressure and approximately a first temperature, is returned to the deheating section of the heat exchanger to exchange heat with the new compressed gas leaving the compressor.

[0101] 4. The method according to any one of embodiments 1 to 3, wherein the gas introduced into the heat exchanger after being injected into its nozzle is repeatedly compressed isothermally or quasi-isothermally to form a closed-loop flow of gas.

[0102] 5. The method according to any one of embodiments 1 to 3, wherein the gas entering the compressor is air under ambient conditions, and the gas leaving the heat exchanger after heat removal is discharged to the surrounding environment.

[0103] 6. The method according to any one of embodiments 1 to 5, wherein HTL is selected from a list including: molten salt, hot oil, ethylene glycol, water, molten metal or any combination thereof.

[0104] 7. The method according to any one of embodiments 1 to 6, wherein the gas is from one of the following: air, nitrogen, argon, CO2 or any combination thereof.

[0105] 8. The method according to any one of embodiments 1 to 7, including monitoring the HTL temperature; and

[0106] Gas can be controllably released from a compressed gas reservoir storing gas at approximately the first pressure and approximately the second temperature into a portion of the flow path between the compressor and the heat receiving section, or directly and controllably released into the heat receiving section.

[0107] The controlled release is based on the HTL temperature to obtain a constant volumetric flow rate injected into the nozzle.

[0108] 9. The method according to any one of embodiments 1 to 8, including monitoring the HTL temperature; and

[0109] Gas is controllably released from a compressed gas reservoir storing compressed gas at approximately the first pressure and approximately the first temperature into a portion of the flow path between the heat receiving portion and the nozzle, or directly and controllably released into the nozzle.

[0110] The controlled release is based on the HTL temperature to obtain a constant volumetric flow rate injected into the nozzle.

[0111] 10. The method according to embodiment 9, wherein the stored gas is at approximately the first pressure and approximately the second temperature;

[0112] The controllable release includes releasing compressed gas into the heat receiving section.

[0113] 11. The method according to any one of embodiments 8 to 10, wherein the compressed gas is at about the second temperature or about the first temperature, wherein the volumetric flow rate from the gas reservoir is determined according to the following formula: Among them, T HTL It is the temperature of HTL. It is the volumetric flow rate or the first time derivative of the volume of the gas entering the nozzle, and the temperature is measured in Kelvin.

[0114] 12. The method according to embodiment 9, wherein the compressed gas is at approximately the first pressure and approximately the first temperature;

[0115] The controlled release includes releasing the stored gas downstream of the heat receiving section and upstream of the nozzle, or releasing it directly into the nozzle.

[0116] 13. The method according to any one of embodiments 1 to 12, comprising maintaining a constant volumetric flow rate of gas in the nozzle within the range of HTL operating temperature.

[0117] 14. The method according to any one of embodiments 1 to 13 includes maintaining equal static pressure at the nozzle inlet or at the mixing region of the nozzle where HTL is mixed with gas and at the proximal end of the outlet region of the nozzle, the static pressure being higher than 50% of the stagnant pressure.

[0118] 15. The method according to any one of embodiments 1 to 14, wherein the first temperature, the first pressure, the second temperature, the second pressure, and the flow rate are within 30% of their nominal values.

[0119] 16. The method according to any one of embodiments 1 to 15, wherein the injection causes the nozzle to rotate, thereby generating work.

[0120] 17. The method according to embodiment 16, wherein the nozzle is part of a reaction turbine.

[0121] 18. The method according to embodiment 17, wherein the injection is performed at a non-zero velocity, which forms a film flow on the injected surface.

[0122] 19. The method according to any one of embodiments 1 to 18, comprising separating the HTL from the gas after the injection.

[0123] 20. The method according to embodiment 19, wherein the separation includes guiding the sprayed mixture onto a curved surface.

[0124] 21. The method according to any one of embodiments 1 to 20 includes retrieving a portion of the sprayed HTL back into the nozzle to undergo another cycle.

[0125] 22. A system for generating work, the system comprising:

[0126] A heating volume section for allowing a heat transfer liquid (HTL) to be heated to a first temperature by a heat source;

[0127] A pump for increasing the pressure of the HTL at the first temperature to a first pressure;

[0128] A compressor, the compression mechanism causing the gas to be compressed to approximately the first pressure;

[0129] A heat exchanger in fluid communication with a compressor and configured to receive compressed gas into a heat receiving portion of the heat exchanger to allow heat transfer to the compressed gas, thereby increasing the temperature of the compressed gas to about the first temperature or below the first temperature;

[0130] A nozzle, which is in fluid communication with a heat exchanger and an HTL pump, has an inlet portion for receiving the HTL and a mixing portion for (i) allowing the HTL at about the first temperature and about the first pressure to be mixed with the gas at or below the first temperature and at about the first pressure to obtain a mixture, and (ii) allowing the mixture to undergo isothermal expansion to reach a second pressure lower than the first pressure, thereby accelerating the mixture at the nozzle toward the nozzle outlet;

[0131] A turbine mechanism that causes the mixture to rotate due to acceleration, thereby converting the kinetic energy of the mixture into work;

[0132] A separation unit for separating HTL and gas, the separation unit including a collection unit for collecting the injected HTL and allowing the injected HTL to be directed to a heating volume, a pump or a nozzle, or toward a nozzle and a heating volume or a pump.

[0133] The separated injected gas is transferred to the heat exchanger's deheating section to exchange heat with the new compressed gas flowing from the compressor in the heat receiving section.

[0134] 23. In the system according to embodiment 22, the cooling gas leaving the heat exchanger's deheating section flows to the compressor, thereby forming a closed-loop gas flow.

[0135] 24. The system according to embodiment 22, wherein the cooled gas leaving the heat exchanger's deheating section flows to the surrounding environment, and the compression mechanism causes gas to be received from the surrounding environment to compress the gas to approximately the first pressure, thereby forming an open system.

[0136] 25. The system according to any one of embodiments 22 to 24, wherein HTL is selected from the group consisting of molten salt, hot oil, molten metal, ethylene glycol, water, or any combination thereof.

[0137] 26. The system according to any one of embodiments 22 to 25, wherein the gas is selected from the group consisting of air, nitrogen, argon, CO2 or any combination thereof.

[0138] 27. A system according to any one of embodiments 22 to 26, comprising a compressed gas reservoir storing compressed gas at about the first pressure and about the second temperature, and in fluid communication with a flow path portion between the compressor and the heat receiving portion;

[0139] The gas reservoir is configured to release gas in a controlled manner based on the sensed temperature of the HTL to obtain a constant volumetric flow rate injected into the nozzle.

[0140] 28. A system according to any one of embodiments 22 to 27, comprising a compressed gas reservoir storing compressed gas at about the first pressure and about the first temperature, and in fluid communication with a flow path portion between a heat receiving portion and a nozzle;

[0141] The compressed gas reservoir is configured to release gas in a controlled manner based on the sensed temperature of the HTL to obtain a constant volumetric flow rate injected into the nozzle.

[0142] 29. The system according to embodiment 27 or 28 includes a temperature sensor configured to sense the temperature of the HTL at at least one location along the flow path of the HTL to generate HTL temperature data based on the temperature, and to transmit the HTL temperature data to a controller of the compressed gas reservoir to control a valve for performing the controlled release.

[0143] 30. The system according to embodiment 29, wherein the temperature sensor is configured to sense the temperature of the HTL at at least one location along the flow path of the HTL between the injection of the HTL from the nozzle and the introduction of the HTL into the nozzle.

[0144] 31. The system according to embodiment 29 or 30, wherein the temperature sensor is configured to sense the temperature of the HTL in the collection unit.

[0145] 32. The system according to embodiment 30 or 31, wherein the compressed gas is at approximately the first pressure and approximately the second temperature; and

[0146] The compressed gas storage unit is in fluid communication with the heat receiving section.

[0147] 33. A system according to any one of embodiments 30 to 32, wherein the compressed stored gas is at about the second temperature or about the first temperature, wherein the volumetric flow rate from the gas reservoir is determined according to the following formula: Among them, T HTL It is the temperature of HTL. It is the volumetric flow rate or the first time derivative of the volume of the gas entering the nozzle, and the temperature is measured in Kelvin.

[0148] 34. The system according to embodiment 30 or 31, wherein the compressed gas is at approximately the first pressure and approximately the first temperature;

[0149] The gas reservoir is in fluid communication with a portion of the flow path between the heat receiving section and the nozzle, or is in direct fluid communication with the nozzle.

[0150] 35. The system according to any one of embodiments 30 to 34, wherein the controller of the compressed gas reservoir is configured to maintain a constant volumetric flow rate of gas in the nozzle within the range of HTL operating temperature.

[0151] 36. A system according to any one of embodiments 22 to 35, wherein the nozzle is configured to maintain equal static pressure at the nozzle inlet or at the mixing volume of the nozzle where the gas is mixed with HTL and at the proximal end portion of the outlet region downstream of the mixing volume, the static pressure being higher than 50% of the stagnant pressure.

[0152] 37. The system according to any one of embodiments 22 to 36, wherein the first temperature, the first pressure, the second temperature, the second pressure, and the flow rate are within 30% of their nominal values.

[0153] 38. The system according to any one of embodiments 22 to 37, wherein the heat source is solar radiation, and the heating volume is configured to receive heat from solar radiation and transfer the heat to the HTL.

[0154] 39. The system according to any one of embodiments 22 to 38, wherein the pump is disposed downstream of the nozzle and upstream of the heating volume.

[0155] 40. The system according to any one of embodiments 22 to 39, wherein the pump is disposed downstream of the heating volume and upstream of the nozzle.

[0156] 41. The system according to any one of embodiments 22 to 40, wherein the nozzle includes the heating volume.

[0157] 42. The system according to any one of embodiments 22 to 41, wherein the nozzle includes a Laval nozzle portion defined between a proximal end and a distal end, wherein the Laval nozzle portion is defined downstream of the mixing portion.

[0158] 43. The system according to embodiment 42, wherein the proximal ends of the inlet portion, the mixing portion and the Laval nozzle portion all have approximately similar maximum cross-sectional areas, wherein each maximum cross-section is defined on a plane perpendicular to the flow direction.

[0159] 44. In the system according to embodiment 43, the maximum cross-section of the mixing section is up to 20% larger than the maximum cross-section of the inlet section.

[0160] 45. The system according to embodiment 43 or 44, wherein the maximum cross-section of the mixing portion is common to the maximum cross-section of the proximal end.

[0161] 46. ​​The system according to any one of embodiments 22 to 45, wherein the turbine includes the nozzle, and the nozzle rotates together with the turbine to generate work.

[0162] 47. The system according to embodiment 46, wherein the turbine is a reaction turbine.

[0163] 48. The system according to embodiment 47, wherein the collection unit defines a discharge section for accumulating separated HTLs, and the HTLs are drawn from the discharge section into a nozzle due to the operation of the reaction turbine, wherein the drawing in causes the HTLs to enter the nozzle at approximately the first pressure.

[0164] 49. A system according to any one of embodiments 22 to 48, wherein the separation unit includes a curved or circular frame, the mixture is sprayed onto the curved or circular frame, and the engagement of the mixture with the curved or circular frame results in a film flow on the surface of the curved or circular frame.

[0165] 50. A system according to any one of embodiments 22 to 49, which is used in a method according to any one of embodiments 1 to 21.

[0166] 51. A nozzle for use in a heat engine, the nozzle comprising:

[0167] The inlet section is used to receive the heat transfer fluid;

[0168] A mixing section for mixing the received HTL with the gas; and

[0169] A Laval nozzle portion, which is defined between a proximal end and a distal end;

[0170] The Laval nozzle portion is defined downstream of the mixing portion, and the mixing portion is defined downstream of the inlet portion; and

[0171] The Laval portion is configured to allow isothermal expansion of the gas between a first pressure and a second pressure below the first pressure.

[0172] 52. The nozzle according to embodiment 51 includes an injection port for allowing gas to be injected into the mixing section.

[0173] 53. The system according to embodiment 51 or 52, wherein the proximal ends of the inlet portion, the mixing portion and the Laval nozzle portion all have approximately similar maximum cross-sectional areas, wherein each maximum cross-section is defined on a plane perpendicular to the flow direction.

[0174] 54. In the system according to embodiment 53, the maximum cross-section of the mixing portion is up to 20% larger than the maximum cross-section of the inlet portion.

[0175] 55. In the system according to embodiment 53 or 54, the maximum cross-section of the mixing portion is common to the maximum cross-section of the proximal end.

[0176] 56. The method according to any one of embodiments 1 to 21, wherein the delivery or the introduction comprises pressurizing the HTL to about the first pressure.

[0177] 57. The system according to embodiment 47 or 48, wherein a portion of the reaction turbine forms the pump.

[0178] 58. The system according to embodiment 57, wherein the pump is disposed or defined between the discharge section and the nozzle.

[0179] 59. The system according to any one of embodiments 22 to 49 or 57 to 58, wherein the first pressure is higher than about 8 bar or higher than 10 bar, and the first temperature is higher than about 100°C.

[0180] 60. The system according to any one of embodiments 22 to 49 or 57 to 59, wherein the flow of the mixture in the nozzle is a supersonic flow.

[0181] 61. The method according to any one of embodiments 1 to 21, wherein the first pressure is higher than about 8 bar or 10 bar, and the first temperature is higher than about 100°C.

[0182] 62. The method according to any one of embodiments 1 to 21 or 61, wherein the flow of the mixture in the nozzle is a supersonic flow. Attached Figure Description

[0183] To better understand the subject matter disclosed herein and to illustrate how it can be implemented in practice, various embodiments will now be described by way of non-limiting example only with reference to the accompanying drawings, in which:

[0184] Figures 1A to 1B This is a block diagram illustrating different, non-limiting examples of implementations of a system according to one aspect of this disclosure.

[0185] Figure 2 The PV and TS diagrams of the hot oil and N2 mixture at 400°C are shown.

[0186] Figure 3 This is a block diagram illustrating a non-limiting example of an implementation of a system according to one aspect of this disclosure.

[0187] Figure 4 This is a schematic diagram of a non-limiting example of a nozzle used in a heat engine according to one aspect of this disclosure.

[0188] Figure 5A and Figure 5B The diagram shows a different view of a non-limiting example of how a part of the system is implemented, where the turbine is a reaction turbine. Figure 5A This is a top view; Figure 5B This is a cross-sectional view. Detailed Implementation

[0189] The following figures illustrate embodiments and implementations of the invention disclosed herein.

[0190] Figure 1A and Figure 1B This is a block diagram illustrating a non-limiting example of a system for generating work according to one aspect of this disclosure. First, refer to... Figure 1A This system provides a heat engine based on an open or closed Ericsson thermodynamic cycle realized over a two-phase flow. System 100 includes a heating volume 102 configured to receive a heat transfer liquid (HTL) from a preheating reservoir 104 and utilizes heat Q provided by an external heat source. 进入The heat transfer fluid (HTL) is heated. The heat source can be any type capable of heating the HTL, such as waste heat extracted from, for example, exhaust gas, molten salt, hot oil, or steam. The HTL is heated to a first temperature in a heating volume 102 and conveyed to an input reservoir 106, which is in fluid communication with the nozzles of a turbine 108 and configured to introduce the heated HTL into the nozzles at a selected and controlled flow rate. The HTL is pressurized to a first pressure before being introduced into the nozzles, or optionally into the nozzles which are part of the impeller in the reaction turbine 108. The pressure increase of the HTL is performed in a preheating reservoir 104, in the input reservoir 106, by the centrifugal force of the reaction turbine (described further below), at any other location in the flow path between the injection of HTL from the turbine and the reintroduction of HTL through the input reservoir 106, or at two or more of these locations. This is typically performed by a pump (not shown). Therefore, the HTL introduced into the nozzle or the multiple nozzles connected to or as part of the turbine 108 is at a first temperature and a first pressure.

[0191] The system also includes a compressor 110 configured to receive gas at a second pressure and compress the gas to a first pressure. Gas compression by the compressor 110 involves the removal of heat Q from the system. 离开 Optionally, the compression is isothermal or quasi-isothermal. The compressed gas, having a first pressure and a second temperature, is directed to the heat receiving section 111 of the counter-current heat exchanger 112 of system 100. The gas is heated to approximately the first temperature in the heat exchanger 112. This is achieved by exchanging heat with hot gas ejected from the turbine, i.e., the regenerator, as explained further below.

[0192] Gas leaving the heat receiving section 111 of the counter-current heat exchanger 112 and being injected into the mixing section of the nozzle of the turbine 108 is mixed with the HTL to obtain a gas-HTL mixture. Thus, gas having approximately a first temperature and a first pressure is mixed with HTL having the same temperature and pressure. It should be noted that a temperature difference or pressure difference may exist between the gas and the HTL. For example, the gas may be injected into the turbine at a temperature or pressure up to 20% lower than that of the HTL. In the nozzle, the mixture undergoes expansion to reach a second pressure lower than the first pressure. In particular, the gas undergoes isothermal or quasi-isothermal expansion because during expansion, heat from the HTL, whose heat capacity is much greater than that of the gas, is transferred to the gas and keeps the gas at approximately the same temperature. The expansion of the gas causes the mixture to accelerate toward the nozzle outlet. The kinetic energy of the accelerated mixture is used to generate work. Typically, the injected mixture causes the turbine to rotate, thus making the turbine a reaction turbine, and this rotation results in the generation of work, i.e., electricity. As described above, the gas and HTL are injected from the nozzle at a second pressure lower than the first pressure. The mixture is injected at approximately a first temperature and directed to the deheating section 113 of the counter-flow heat exchanger 112 to exchange heat with the gas passing through the heat receiving section 111 of the counter-flow heat exchanger 112. Therefore, the gas exiting the deheating section 113 of the counter-flow heat exchanger 112 is at approximately a second temperature and approximately a second pressure. The gas exiting the deheating section 113 of the counter-flow heat exchanger 112 is directed to the compressor 110 to undergo another cycle in the system. The increase and decrease in temperature of the gas in the heat exchanger 112 are carried out isobarically or near isobarically.

[0193] It should be noted that in some embodiments of this system, the gas is air, and as the gas exits from the heat removal section 113 of the counter-current heat exchanger 112, it is released into the environment, and ambient air is introduced into the compressor 110. Therefore, the system can operate in either a closed or open loop.

[0194] The HTL injected from the nozzle of turbine 108, or only a portion thereof, is directed to preheating reservoir 102 to undergo another cycle in the system.

[0195] Now refer to Figure 1B It shows that, due to the inclusion of a compressed gas reservoir 117 and a separation unit 119, it is related to... Figure 1ADifferent systems exist. Two alternative implementations exist for the compressed gas reservoir 117. In a first alternative implementation, the compressed gas reservoir 117 includes compressed gas, such as air, at approximately a first pressure and approximately a second temperature, and is connected to a flow path between the compressor 110 and the counter-flow heat exchanger 112 to release the compressed gas into the heat receiving section of the counter-flow heat exchanger 112. In a second alternative implementation, the compressed gas reservoir 117 includes hot compressed gas, such as air, at approximately a first temperature and approximately a first pressure, and is connected to a flow path between the counter-flow heat exchanger 112 and the turbine 108 or the nozzle of the turbine 108 to release the hot compressed gas downstream of the heat receiving section of the counter-flow heat exchanger 112. It should be noted that in a typical implementation of the system, only one of the two alternatives to the compressed gas reservoir is used. As will be understood, the connection between the compressed gas reservoir 117 and the standard flow path of the system can be bidirectional. This allows the compressed gas reservoir 117 to be filled with hot or cold compressed gas for later use when needed. This step of filling the compressed gas reservoir 117 can be performed as a preparatory step before standard system operation. The controller (not shown) of the compressed gas reservoir 117 is configured to control the release of gas based on the temperature of the HTL sensed in the collection unit 121 of the separation unit 119 or in the input reservoir 106. Optionally, the compressed gas reservoir 117 has an input terminal connected to the compressor and an output conduit connected to a heat exchanger. Optionally, a control valve located at the output conduit of the compressed gas reservoir controls the flow rate based on flow meter and thermometer readings.

[0196] Separation unit 119 is configured to separate the gas and HTL from the gas-HTL mixture after it has been ejected from the nozzle. For example, separation unit 119 may include a curved surface onto which the mixture is ejected, and the contact with the surface causes the flow on the surface to be subjected to centrifugal force, resulting in separation of the HTL from the gas. The HTL is collected in collection unit 121, which defines a discharge section. A portion of the HTL is delivered back to preheating reservoir 104 and then to heating volume 102 for reheating, while another portion is delivered back to turbine 108 for another cycle. In embodiments where turbine 108 is a reaction turbine, i.e., a system in which the nozzle rotates due to the ejection of the mixture from the nozzle to generate electricity, operation of turbine 108 causes a suction state in the discharge section of collection unit 121, thereby drawing HTL from the discharge section into the nozzle at approximately a first pressure. Furthermore, the portion of the HTL delivered for reheating in the heating volume 102 can be returned to the discharge section at approximately a second pressure, and pumped back to the nozzle at approximately a first pressure due to the suction state caused by the reaction turbine. This is discussed below regarding... Figure 5A and Figure 5B Further examples.

[0197] Optionally, in any of the above embodiments, the operating temperature of the nozzle, i.e., the first temperature, is 100°C or higher; and the operating pressure of the nozzle, i.e., the first pressure, is 10 bar or higher.

[0198] The Ericsson cycle ideally supports Carnot efficiency, and the work produced by the system is Any other heat loss in the turbine can optionally remain as heat in the system. Figure 2 The thermodynamic cycle TS and PV diagrams are depicted. The pseudo-isothermal process allows the HTL to cool several degrees with expansion while supporting high output power. Generally, the HTL can be any liquid carrying heat, such as molten metal, molten salt, hot oil, or water, and can also be a liquid containing soluble materials, such as water containing NaCl, ZnCl2, or NaOH, or other soluble materials known to raise the boiling point, thus allowing, for example, a heat engine to be driven in the aqueous phase at temperatures above 100°C.

[0199] The gas in the system can be air, nitrogen, argon, CO2, helium, or any other gas suitable for realizing such a system.

[0200] In some implementations of the above system, it can be used to provide constant output power at a constant voltage frequency.

[0201] In the Ericsson cycle, isobaric heating maintains pressure regardless of the HTL temperature. Lower HTL temperatures result in less thermal expansion accompanying heating, and consequently, a lower volumetric flow rate of gas injected into the HTL. Increasing the volumetric flow rate does not change the following equation: This is achieved by adding a compressed gas tank or compressed gas reservoir between the compressor and the nozzle (not shown) to store a sufficient amount of additional gas when the HTL is at a cryogenic temperature. Optionally, the gas reservoir is located between the compressor and the heat exchanger at a cryogenic compression temperature. Optionally, the reservoir is located between the heat exchanger and the nozzle to store hot gas. Flow control is achieved via a valve controlled by a control unit fed with data on the monitored HTL temperature in the system.

[0202] Now refer to Figure 3 , Figure 3 This is a block diagram illustrating an implementation of the system, wherein the heat source is in the form of solar radiation.

[0203] Throughout the accompanying drawings of the application, similar elements in different drawings are given similar reference numerals, which are varied by aligning the hundreds digit with the corresponding drawing number. For example, Figure 3 Component 308 in Figure 1 provides the same function as component 108 in Figure 1.

[0204] In this non-limiting example, the heating volume 302 is heated by solar radiation and is part of or located near the turbine 308. Therefore, the HTL cycle can proceed at very low temperature differences due to minimal head loss. For example, the difference between the HTL entering and leaving the turbine 308 can be 10 degrees Celsius or 50 degrees Celsius. In some embodiments, the turbine includes a heating volume, and the entire HTL volume is simultaneously cooled by the turbine and heated by solar radiation, thereby maintaining a constant average temperature. This allows for low-degree temperature reductions. Once solar radiation is no longer available as a heat source, the turbine can be operated using both cold and hot HTL reservoirs as shown in Figure 1 above.

[0205] Now refer to Figure 4 , Figure 4 This is a schematic diagram of a nozzle 320 that can be used in any configuration of the system disclosed herein. The nozzle 320 is formed by three consecutive portions: an inlet portion 322 in fluid communication with a supply of hot and pressurized HTL; a mixing portion 324 configured to mix the HTL with the injected gas; and a de Laval portion 326 undergoing isothermal expansion. The de Laval portion 326 extends between a proximal end 328 bordering the mixing portion 324 and a distal end 330 that typically serves as the nozzle outlet. Due to the unique configuration of the system, the inlet portion 322 of the nozzle 320 is allowed to be as wide as needed and at the same pressure as the beginning of the outlet section of the nozzle where the pressure is highest. The inlet portion 322 and the mixing portion 324 have approximately the same cross-sectional area as the proximal end 328 of the outlet, which typically defines the location of the maximum area and maximum pressure. This also results in the pressure in the inlet portion 322 and the mixing portion 324 being approximately the same as the pressure in the proximal end 328. The slight widening of the cross-section of the mixing portion 324 is less than 20% of the minimum cross-section of the mixing portion 324 and is due to the additional volume of the injected gas. Therefore, the maximum horizontal cross-section of the inlet portion 322 defined on the first plane P1 and the maximum horizontal cross-section of the mixing portion 324 defined on the second plane P2 and the proximal end of the Laval portion 326 have approximately the same area, i.e., a difference of less than 20%.

[0206] Optionally, the Laval nozzle shape is determined according to the Laval equation cited in the following reference: “Thrust Enhancement Through Bubble Injection Into an Expanding-Contracting Nozzle With a Throat”, Sowmitra Singh, Tiffany Fourmeau, Jin Keun Choi, Georges, and L. Chahine, DOI:10.1115 / 1.4026855. This nozzle has been explored for use in marine propulsion at pressures below 10 bar and temperatures below 100°C. Compared to marine propulsion, the thermal cycle of this invention operates at maximum pressure and temperature. Figure 4 It is an optional geometry for Laval two-phase flow nozzles with pressures above 10 bar and temperatures above 100°C. The difference is hidden in the mixture velocity and the nozzle geometry.

[0207] Figure 5A and Figure 5B The diagram shows a different view of a non-limiting example of an implementation of the systems and methods disclosed herein, wherein the turbine is a reaction turbine. Turbine 508 is a five-nozzle reaction turbine. Turbine 508 includes a discharge section 552 as part of a collection unit 521. Discharge section 552 includes HTL collected after being injected from the nozzles. HTL is drawn from discharge section 552 into impeller 554, which generates centrifugal force as it rotates. The suction state that causes HTL to be drawn into impeller 554 is due to the operation of the turbine, i.e., the injection of the mixture through the nozzles. A portion of the HTL in discharge section 552 passes through a heating outlet 553, which guides the HTL to a heating volume, where the HTL is heated. The HTL may pass through a preheating reservoir before reaching the heating volume. The reheated HTL then circulates back to (i) the discharge section 552 through the hot HTL inlet 555, or (ii) directly into the turbine 508 or impeller 554 without mixing with the HTL in the discharge section 552. A gas, such as air or any other suitable gas, is optionally supplied through a gas inlet 556 at the center of the shaft 558 and reaches a nozzle 520 with a contraction-expansion Laval shape located at the outer circumferential diameter of the impeller 554. The acceleration of the mixture drives the turbine 508, and thus the shaft drives an electromagnetic generator. The jet of the mixture exits the nozzle with a non-zero velocity and impacts the circular wall 562 of the turbine 508 housing 564, creating a film flow on the wall that separates the mixture. The HTL flows into the discharge section 552 to circulate back into the impeller 554.

[0208] Unless otherwise specified, “about” throughout the application should be interpreted as a deviation of ±20% from the nominal value or from the nominal reference value. For example, if the value is about 10, it should be understood to be in the range of 8-12. In another example, if the reference is to a first temperature, it should be understood that the temperature may deviate from the first temperature by ±20%, which can be characterized by the temperature of different materials.

[0209] Example

[0210] Without any theoretical constraints, the following is an example of the controlled volume calculation of Therminol 66 and nitrogen (N2) at 400°C for a 100kW solar receiver designed according to the above system implementation.

[0211] Consider the volume of N2 in the inertial frame of reference.

[0212] Step 1: From 3m 3 A controlled volume of N2 reaches the compressor under ambient conditions to begin operation.

[0213] P1V1=nRT1=>n=120.272mol.=>m=3.367Kg of N2

[0214] According to the ideal gas equation PV = nRT, increasing the gas pressure from approximately 1 bar to 40 bar reduces the volume to 0.075 m³. 3 When the process isothermally completes, the heat removed from the gas into the surrounding environment is:

[0215] Q1=W1=P1V1 ln(V2 / V1)=1.107MJ.

[0216] The entropy decreases to dS = Q1 / T = 3.69 kJ / K.

[0217] Step 2: Heat nitrogen and oil to 673K ​​under constant pressure.

[0218] heat capacity is The resulting input heat is:

[0219] Q2 = 3.36 * 1.04 * ΔT N2 =1.33MJ

[0220] And its volume is: 0.075m³ 3 *673K / 300K=0.168m 3

[0221] Step 3: Expansion occurs approximately isothermally, generating work in the process;

[0222] Q3=W3=V3P32 ln(V4 / V3)=0.168m 3 *40Bar*ln(40)=2.48MJ

[0223] The entropy decreases to dS = Q³ / T = 3.69 kJ / K.

[0224] Step 4: Cool N2 at the heat exchanger, Q4 = Q2.

[0225] These steps are in Figure 2 The diagram is described by PV diagrams and TS diagrams.

[0226] The ideal efficiency of this cycle is:

[0227] This is equivalent to a Carnot cycle.

[0228] Assuming 90% isothermal compression and expansion efficiency, the actual efficiency is:

[0229]

[0230] Assuming the turbine's heat losses are retained in the system for reuse, the actual efficiency is:

[0231]

[0232] The final assumption and calculations achieved higher efficiency than the previous isochoric heating cycle, in which only a portion of the heat from the departing gas was recovered.

[0233] This advantage paved the way for highly efficient reaction turbines. Conventionally, HTLs are considered less efficient than impulse turbines, such as the Pelton turbine, because they exit the nozzles of a reaction turbine under load at a non-zero velocity. However, this loss is converted into heat through friction and retained at the turbine for recovery.

Claims

1. A method for generating work, the method comprising: heating a heat transfer liquid (HTL) within the heating volume to a first temperature and delivering the heat transfer liquid to an inlet of a nozzle at about a first pressure; compressing a gas to about the first pressure by a compressor and heating the compressed gas to about the first temperature or below within a heat receiving portion of a heat exchanger; mixing, in the nozzle, the heat-transfer liquid at the first pressure and the first temperature with a compressed gas at about the first pressure and about the first temperature or below about the first temperature to obtain a mixture of gas and heat-transfer liquid, wherein after the mixing, the gas and the heat-transfer liquid in the mixture reach approximately the same temperature; allowing gas in the mixture to undergo isothermal or quasi-isothermal expansion within the nozzle to reach a second pressure lower than the first pressure, thereby accelerating the mixture toward an outlet of the nozzle; ejecting the mixture through the outlet to produce mechanical work; introducing the injected gas into a heat removal portion of the heat exchanger to exchange heat with compressed gas leaving the compressor; and At least a portion of the injected heat transfer liquid is directed towards the heating volume.

2. The method according to claim 1, wherein: The compression comprises isothermal or quasi-isothermal compression of the gas.

3. A method for realizing a heat engine, the method comprising: introducing a heat transfer liquid (HTL) into the nozzle at a first pressure and a first temperature; compressing the gas isothermally from a second pressure and a second temperature to the first pressure by a compressor, wherein the second pressure and the second temperature are lower than the first pressure and the first temperature, respectively; heating compressed gas exiting the isothermal compressor at a first pressure and a second temperature to about the first temperature by passing the compressed gas through a heat receiving portion of a counter-flow heat exchanger; injecting heated gas exiting the heat receiving portion of the heat exchanger into the nozzle to obtain a mixture of heat transfer liquid and gas, thereby isothermally or quasi-isothermally expanding the mixture to the second pressure, thereby causing the mixture to accelerate in the nozzle; and spraying the accelerated mixture from an outlet of the nozzle; The injected gas at about the second pressure and about the first temperature is withdrawn to a heat removal portion of the heat exchanger to exchange heat with new compressed gas exiting the compressor.

4. The method according to any one of claims 1 to 3, wherein: The gas introduced into the heat exchanger after the injection of the gas from the nozzle is repeatedly isothermally or quasi-isothermally compressed, thereby forming a closed-loop flow of the gas.

5. The method according to any one of claims 1 to 3, wherein: The gas entering the compressor is air at ambient conditions and the gas leaving the heat exchanger after heat removal is discharged to the surrounding environment.

6. The method according to any one of claims 1 to 5, wherein: The heat transfer liquid is selected from the list comprising: molten salt, hot oil, glycol, water, molten metal or any combination thereof.

7. The method according to any one of claims 1 to 6, wherein: The gas is one from the list consisting of: air, nitrogen, argon, CO2 or any combination thereof.

8. A method according to any one of claims 1 to 7, comprising monitoring the heat transfer liquid temperature; and controllably releasing gas from a compressed gas storage storing stored gas at about the first pressure and at about the second temperature into a portion of a flow path of the gas between the compressor and the heat receiving portion or directly into the heat receiving portion; in, The controllably releasing is based on the temperature of the heat transfer liquid to achieve a constant volumetric flow rate injected into the nozzle.

9. A method according to any one of claims 1 to 8, comprising monitoring the heat transfer liquid temperature; and controllably releasing gas from a compressed gas reservoir storing compressed gas at about the first pressure and at about the first temperature into a portion of a flow path between the heat receiving portion and the nozzle, or directly into the nozzle; in, The controllably releasing is based on the temperature of the heat transfer liquid to achieve a constant volumetric flow rate injected into the nozzle.

10. The method according to claim 8 or 9, wherein: The volume flow from the gas reservoir is determined according to the following formula: Among them, T HTL is the temperature of the heat transfer liquid, is the volume flow rate or the first time derivative of the volume of gas entering the nozzle, and the temperature is in Kelvin.

11. A method according to any one of claims 1 to 10, comprising maintaining a constant volumetric flow rate of gas in the nozzle over a range of heat transfer liquid operating temperatures.

12. A method according to any one of claims 1 to 11, comprising maintaining equal static pressures at the inlet of the nozzle or at a mixing zone of the nozzle where the heat transfer liquid is mixed with the gas and at the proximal end of the outlet zone in the nozzle, the static pressure being higher than 50% of the stagnation pressure.

13. The method according to any one of claims 1 to 12, wherein: The jet causes the nozzle to rotate, thereby producing work.

14. The method according to claim 13, wherein: The nozzle is part of a reaction turbine.

15. The method according to claim 14, wherein: The injection is performed at a non-zero velocity, which creates a film-like flow on the surface onto which it is injected.

16. A method according to any one of claims 1 to 15, comprising separating heat transfer liquid from gas after said injecting.

17. The method according to claim 16, wherein: The separating includes directing the injected mixture onto a curved surface.

18. The method of any one of claims 1 to 17, comprising withdrawing a portion of the injected heat transfer liquid back into the nozzle to undergo another cycle.

19. The method according to any one of claims 1 to 18, wherein: The first pressure is above about 8 bar and the first temperature is above about 100°C.

20. The method according to any one of claims 1 to 19, wherein: The flow of the mixture in the nozzle is a supersonic flow.

21. A system for generating work, the system comprising: a heating volume for allowing a heat transfer liquid (HTL) to be heated to a first temperature by a heat source; a pump for increasing the pressure of the heat transfer fluid at the first temperature to a first pressure; a compressor configured to compress the gas to about the first pressure; a heat exchanger in fluid communication with the compressor and configured to receive compressed gas into a heat receiving portion of the heat exchanger to allow heat to be transferred to the compressed gas to increase the temperature of the compressed gas to or below about the first temperature; a nozzle in fluid communication with the heat exchanger and the heat transfer liquid pump, the nozzle having an inlet portion for receiving the heat transfer liquid and a mixing portion for (i) allowing the heat transfer liquid at about the first temperature and about the first pressure to mix with the gas at or below about the first temperature and at about the first pressure to obtain a mixture, and (ii) allowing the mixture to undergo isothermal expansion to a second pressure lower than the first pressure, thereby accelerating the mixture at the nozzle toward an outlet of the nozzle; a turbine configured to rotate due to the acceleration of the mixture, thereby converting kinetic energy of the mixture into work; a separation unit for separating the heat transfer liquid from the gas, the separation unit comprising a collection unit for collecting the injected heat transfer liquid and allowing the injected heat transfer liquid to be directed to the heating volume, the pump or the nozzle, or towards the nozzle and one of the heating volume or the pump; The separated injected gas is transferred to the heat removing part of the heat exchanger to exchange heat with new compressed gas flowing from the compressor in the heat receiving part.

22. The system of claim 21, wherein: Cooled gas leaving the heat removal portion of the heat exchanger flows to the compressor, thereby forming a closed loop flow of gas.

23. The system of claim 21, wherein: The cooled gas exiting the heat removal portion of the heat exchanger flows to an ambient environment, and the compressor is configured to receive gas from the ambient environment to compress the gas to about the first pressure, thereby forming an open system.

24. A system according to any one of claims 21 to 23, wherein: The heat transfer liquid is selected from the group consisting of molten salt, hot oil, molten metal, glycol, water, or any combination thereof.

25. A system according to any one of claims 21 to 24, wherein: The gas is selected from the group consisting of air, nitrogen, argon, CO2 or any combination thereof.

26. The system of any one of claims 21 to 25, comprising a compressed gas reservoir storing compressed stored gas at about the first pressure and about the second temperature and in fluid communication with a portion of the flow path between the compressor and the heat receiving portion, or in fluid communication directly with the heat receiving portion; in, The gas reservoir is configured to controllably release gas based on the sensed temperature of the heat transfer liquid to achieve a constant volumetric flow rate injected into the nozzle.

27. The system of any one of claims 21 to 26, comprising a compressed gas reservoir storing compressed stored gas at about the first pressure and about the first temperature and in fluid communication with a portion of the flow path between the heat receiving portion and the nozzle, or in fluid communication directly with the nozzle; in, The gas reservoir is configured to controllably release gas based on the sensed temperature of the heat transfer liquid to achieve a constant volumetric flow rate injected into the nozzle.

28. The system according to claim 26 or 27 comprises a temperature sensor, which is configured to sense the temperature of the heat transfer liquid in at least one position along the flow path of the heat transfer liquid to generate heat transfer liquid temperature data based on the temperature of the heat transfer liquid, and transmit the heat transfer liquid temperature data to the controller of the gas storage device to control the valve used to perform the controlled release.

29. The system of claim 28, wherein: The temperature sensor is configured to sense a temperature of the heat transfer liquid in at least one location along a flow path of the heat transfer liquid between ejection of the heat transfer liquid from the nozzle and introduction of the heat transfer liquid into the nozzle.

30. The system of claim 28 or 29, wherein: The temperature sensor is configured to sense the temperature of the heat transfer liquid in the collection unit.

31. A system according to any one of claims 21 to 30, wherein: The nozzle is configured to maintain equal static pressures above 50% of the stagnation pressure at the inlet of the nozzle or at a mixing volume where gas and heat transfer liquid are mixed and at a proximal end portion of the outlet region downstream of the mixing volume.

32. A system according to any one of claims 21 to 31, wherein: The heat source is solar radiation, and the heating volume is configured to receive heat from the solar radiation and transfer the heat to a heat transfer liquid.

33. A system according to any one of claims 21 to 32, wherein: The pump is arranged downstream of the nozzle and upstream of the heating volume.

34. A system according to any one of claims 21 to 32, wherein: The pump is arranged downstream of the heating volume and upstream of the nozzle.

35. A system according to any one of claims 21 to 34, wherein: The nozzle includes the heating volume.

36. A system according to any one of claims 21 to 35, wherein: The nozzle includes a Laval nozzle portion defined between a proximal end and a distal end, wherein the Laval nozzle portion is defined downstream of the mixing portion.

37. The system of claim 36, wherein: the inlet portion, the mixing portion, and the proximal end of the Laval nozzle portion all have approximately similar maximum cross-sectional areas, wherein each maximum cross-sectional area is defined in a plane perpendicular to a direction of flow; wherein the maximum cross-section of the mixing section is up to 20% greater than the maximum cross-section of the inlet section; and Therein, the maximum cross-section of the mixing portion is common to the maximum cross-section of the proximal end.

38. A system according to any one of claims 21 to 37, wherein: The turbine includes the nozzle, and the nozzle rotates with the turbine to generate work.

39. The system of claim 38, wherein: The turbine is a reaction turbine.

40. The system of claim 39, wherein: The collection unit defines a discharge for accumulating separated heat transfer liquid, and heat transfer liquid is sucked from the discharge into the nozzle due to operation of the reaction turbine, wherein the suction causes the heat transfer liquid to enter the nozzle at about the first pressure.

41. A system according to claim 39 or 40, wherein: A portion of the reaction turbine forms the pump.

42. A system according to any one of claims 21 to 41, wherein: The separation unit comprises a curved or circular frame onto which the mixture is sprayed, the engagement of the mixture with the curved or circular frame causing a film-like flow to be generated on the surface of the curved or circular frame.

43. A system according to any one of claims 21 to 42, wherein: The first pressure is above about 8 bar and the first temperature is above about 100°C.

44. A system according to any one of claims 21 to 43, wherein: The flow of the mixture in the nozzle is a supersonic flow.

45. A system according to any one of claims 21 to 44, for use in a method according to any one of claims 1 to 20.

46. ​​A nozzle for use in a heat engine, the nozzle comprising: an inlet portion for receiving a heat transfer fluid; a mixing section for mixing the received heat transfer fluid with the gas; as well as a Laval nozzle portion defined between the proximal end and the distal end; wherein the Laval nozzle portion is defined downstream of the mixing portion, and the mixing portion is defined downstream of the inlet portion; and The Laval portion is configured to allow isothermal expansion of a gas between a first pressure and a second pressure lower than the first pressure.

47. A nozzle according to claim 46, comprising an injection port for allowing gas to be injected into the mixing section.

48. A system according to claim 46 or 47, wherein: the inlet portion, the mixing portion, and the proximal end of the Laval nozzle portion all have approximately similar maximum cross-sectional areas, wherein each maximum cross-sectional area is defined in a plane perpendicular to a direction of flow; wherein the maximum cross-section of the mixing section is up to 20% greater than the maximum cross-section of the inlet section; and Therein, the maximum cross-section of the mixing portion is common to the maximum cross-section of the proximal end.

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