Two-phase isothermal compressor and condenser nozzle

Abstract

The present disclosure provides a nozzle design that allows compression and / or condensation of gas or vapors presence in a liquid entering the nozzle. In the nozzle configuration of the present disclosure, the stream that flows through the nozzle is a two-phase steam and it reaches a supersonic flow before the suction of the additional vapors begins. By the end of the first narrowing section, the flow within the nozzle is supersonic, followed by a first expanding section that further reduces the pressure of the stream and increases the Mach number before the suction section that follows it, which maintains the pressure and the supersonic conditions.

Description

[0001] TWO-PHASE ISOTHERMAL COMPRESSOR AND CONDENSER NOZZLE

[0002] TECHNOLOGICAL FIELD

[0003] The present disclosure is generally in the field of pressurization devices, and more specifically relates to a two-phase nozzle for pressurization of compressible fluids.

[0004] BACKGROUND

[0005] A conventional compressing element for a two-phase media flow may, for example be a Venturi nozzle which is a type of a converging-diverging passive compression device with no moving parts. A self-entrainment venturi nozzle has the same operating principle as a regular venturi nozzle but is also equipped with one or more gas inlets. Typically, a self-entrainment venturi nozzle features a convergent inlet section, a divergent outlet section and possibly a constricted throat therebetween. Generally, Venturi nozzles use a fast-flowing liquid to entrain a nearly quiescent suction compressible fluid (e.g., gas). In a self-entrainment venturi nozzle, the motive stream is accelerated by flowing through the converging section while the pressure of the motive stream is reduced at the end of the converging section beyond ambient pressure, with the highest velocity achieved at the throat of the nozzle. The high velocity of the liquid creates a region of low static pressure and therefore a pressure difference between the liquid at the throat of the nozzle and the suction fluid. The pressure difference draws the suction fluid flow into the nozzle through the gas inlets(s), where the suction and motive streams mix to form a two-phase media, typically in the constricted throat section. A following diverging section may increase the pressure of the gas / liquid mixture. Due to the high volumetric heat capacity of the liquid, the increase in pressure is isothermal or quasiisothermal.

[0006] However, in such nozzles, the flow velocity of the two-phase media is limited to sub-sonic flow, relevant to low pressure levels of compression. Aiming to higher pressures of compression requires higher flow velocities at the suction area, which easily reaches supersonic velocity at high gas / liquid mixture flow rates. This may induce shock waves, which may reduce suction efficiency, output pressure, and total efficiency.

[0007] WO20222 / 234554, WO2024 / 062465 and W02024 / 100669 describe fluid pressurization devices and techniques for an efficient isothermal or quasi-isothermal pressurization of fluids and compression of gas such as atmospheric air or other gases and vapors, which are the working fluid (WF). In that prior art, pressurized Heat Transfer Liquid (HTL) flows in a converging nozzle reducing the pressure to below ambient, sucking vapors or gasses into a diverging mixing chamber, creating a supersonic 2-phase nozzle. Following a reversed De-Laval geometry where the supersonic converging section increases pressure and reduces Mach number to unity, following a diverging subsonic section that retrieves the high-pressure minus head losses and minus the invested work. The mixture is compressed, and the vapor optionally condenses. The compression, and optionally, condensation lead to heat transfer from the WF to the HTL, maintaining A quasi-isothermal compression and condensation. Next, the mixture is separated, resulting in a separated compressed or condensed WF. The HTL passes through a heat exchanger to remove the compression heat and continues to circulate back into the nozzle.

[0008] Figs. 1A-1B show the prior art of two-phase supersonic reversed De-Laval nozzle and a compressor device, respectively.

[0009] Optionally, such a compressor is used as part of a heat pump (as exemplified in Fig. 2), where the liquid-phase WF flows into a recuperator and cools, next to a vaporizer as depicted in the following figure. As teaches the prior art, optionally such a heat pump is part of an isothermal Carnot battery.

[0010] Separating the two fluid mixtures exiting the compressor is challenging and costly. Optionally, the condenser is maintained at a temperature below the saturation temperature (sub-cold), where the compressed WF is at the vapor phase at the compressor. This reduces the separation challenge by separating two different phases. The vapors flow to a condenser for condensation at a lower temperature than the compressor. However, a two-phase separator is a large and costly device. Also, the condenser is a costly device. Another challenge is a non-ideal separation, which results in a small amount of WF that circulates and reaches the inlet of the nozzle, arrests pressure drops (the inlet converging section in Figure 1) and reduces the compression efficiency. Finally, also the condenser is a large and costly component. Here we describe a method and apparatus for a two- phase isothermal compressor, heat pump, and Carnot battery, that doesn’t require a separator and condenser. GENERAL DESCRIPTION

[0011] The present disclosure provides a design of a two-phase nozzle that can be used in compressor, heat pump, or Carnot battery that maintains high efficiency while a portion of vapors or gas phase reaches the inlet converging section. This is relevant for a nonideal separation of two different liquids, and also where the HTL and the WF are the same liquid, which eliminates the need for a separator and condenser. The presence of WF in the nozzle inlet, in the prior art, while reducing the pressure at the converging section WF may evaporate, which arrests the pressure drop and the compression efficiency. In this unique nozzle configuration, the stream that flows through the nozzle reaches a supersonic flow before the suction of the additional vapors begins. By the end of the first narrowing section, the flow within the nozzle is supersonic, followed by a first expanding section that further reduces the pressure of the stream and increases the Mach number before the suction section that follows it, which maintains the pressure and the supersonic conditions.

[0012] Therefore, an aspect of the present disclosure provides a nozzle for pressurizing fluid. The nozzle comprises a nozzle inlet for receiving a two-phase liquid-gas stream or flow into the nozzle (hereinafter, two-phase stream). The two-phase liquid-gas stream entering the nozzle inlet comprises (1) a gas portion of either a heat transfer liquid (HTL), a working fluid (WF) or a combination of HTL and WF; and (2) a liquid portion of said HTL.

[0013] The nozzle further comprises an outlet; a suction fluid inlet; and an arrangement of fluid manipulation sections arranged in fluid communication in a cascaded fashion and defining a flow path of said two-phase stream. It is to be noted that the two-phase flow changes its void fraction along the flow in the nozzle, between a minimum value that can be near-zero up to a maximum value according to the design of the nozzle and the material of the two-phase flow.

[0014] The arrangement of fluid manipulation sections comprises a second fluid manipulation section downstream the nozzle inlet. The second fluid manipulation section can be directly coupled to the nozzle inlet or typically coupled to the nozzle inlet through an additional fluid manipulation section. The second fluid manipulation section comprises an expanding configuration in the direction of said flow path for reducing the two-phase stream pressure below a pressure of a suction fluid, typically WF gas in ambient pressure, while maintaining a supersonic flow of the two-phase stream. The suction fluid is the same material as the WF and typically the same material as the gas of said two-phase stream.

[0015] The arrangement further comprises a third fluid manipulation section downstream the second fluid manipulation section having an expanding configuration, that may be of the same expansion rate profile or different than the second fluid manipulation section, and is configured for receiving the two-phase stream flowing from the second fluid manipulation section at a pressure below the pressure of the suction fluid, or below ambient pressure in which the suction fluid is in. The suction fluid inlet is configured for allowing suction fluid communication between a suction fluid source, that comprises said suction fluid (this can be either the ambient or a tank containing the suction fluid), and said third fluid manipulation section to be mixed with the two-phase stream to thereby obtain two-phase flow at higher gas fraction while maintaining the two-phase supersonic flow at about constant pressure, namely ±20% from a nominal value at the beginning of the third fluid manipulation section, here the pressure value. In other words, the third fluid manipulation section is configured to allow introduction of suction fluid thereinto. The suction fluid inlet can be a conduit, a pipe, or an array of pipes, a perforation arrangement or any other suitable solutions.

[0016] The arrangement further comprises a fourth fluid manipulation section downstream the third fluid manipulation section having a narrowing configuration in the direction of said flow path for increasing the pressure and reducing the Mach number of the two-phase stream. The two-phase stream may reach subsonic flow at about the end of the fourth fluid manipulation section so as to ensure that along the majority of the fourth fluid manipulation section, the two-phase stream flow is supersonic and therefore the pressure increases along the flow path of the two-phase stream therein. The term "about" should be understood that the two-phase stream reaches subsonic flow either slightly before the end of the fourth fluid manipulation section or slightly after the end of the fourth manipulation section, i.e. either at a connecting section to the fifth fluid manipulation section or at the beginning of the fifth fluid manipulation section. In some embodiments, the term "about" in this context should be understood as a distance of ±20% of the entire length of the fourth fluid manipulation section.

[0017] The arrangement further comprises a fifth fluid manipulation section downstream the fourth fluid manipulation section and having an expanding configuration in the direction of said flow path and configured for increasing pressure of the two-phase stream to a pressure above the suction fluid source, e.g. above ambient pressure. The two-phase stream is either maintained in a two-phase state or transitions to a single-phase state at the end of the fifth fluid manipulation section, namely it is either discharged from the nozzle as liquid or liquid with bubbly media therein. The outlet is downstream the fifth fluid manipulation section or is constituted by a distal end thereof and is for discharging the two-phase flow received from the fifth fluid manipulation section, wherein the fluid mixture discharged from the outlet comprises pressurized suction fluid.

[0018] The numbers given to the fluid manipulation sections are used only to differentiate between the sections and to ease the understanding of their arrangement along the flow path. The first fluid manipulation section is absent from the above description as it appears in further specific definitions of the nozzle below. The first manipulation section is upstream the second manipulation section and therefore, for ease of description, the broad definition of the invention does not include a first fluid manipulation section.

[0019] It should be understood that any combination of the described embodiments is contemplated and within the scope of this disclosure. Each aspect, feature, or element disclosed herein may be combined with any other aspect, feature, or element, whether or not explicitly described in combination, unless such combination would be technically impossible or contradictory. In particular, any aspect of the present disclosure can be defined by any combination of the described embodiments.

[0020] In some embodiments, the nozzle further comprises a first fluid manipulation section downstream to the nozzle inlet and upstream the second fluid manipulation section having a narrowing configuration in a direction of said flow path for reducing pressure of the two-phase stream streamed thereinto while accelerating it until reaching supersonic flow, namely Mach=l or above, of said two-phase stream.

[0021] In some embodiments of the nozzle, the suction fluid streamed into the first fluid manipulation section has a subsonic velocity.

[0022] In some embodiments of the nozzle, the fourth fluid manipulation section is configured to reduce the number of the two-phase stream to about Mach=l therealong. The term "about" Mach=l should be understood as a deviation of ±10%, 5%, 4%, 3%, 3%, or 1% of Mach=l.

[0023] In some embodiments of the nozzle, the HTL comprises at least one of water, molten salt, thermal oil, ethylene glycol, molten metal, hydro-carbonate liquids, antifreezing liquids, liquified gases, or any combination thereof. In some embodiments of the nozzle, the suction fluid is gas or vapor.

[0024] In some embodiments of the nozzle, the WF comprises at least one of air, argon, CO2, hydrogen, natural gas, nitrogen, organic vapors, steam, refrigerant gases, gases used in organic Rankine cycle (ORC), or any combination thereof.

[0025] In some embodiments of the nozzle, the suction fluid inlet comprises at least one conduit extending from an exterior thereof into the third fluid manipulation section and configured for channeling the suction fluid into the third fluid manipulation section.

[0026] In some embodiments of the nozzle, the at least one conduit is connectable to an external suction fluid source.

[0027] In some embodiments of the nozzle, said nozzle inlet is configured to be in fluid communication with a two-phase stream source for receiving said two-phase stream in a pressure greater than ambient pressure.

[0028] In some embodiments of the nozzle, the HTL and the WF are the same material. In some other embodiments, the HTL and the WF are different materials and a portion of the HTL is in a vapor phase at the inlet of the nozzle.

[0029] In some embodiments of the nozzle, the geometrical profile of any one of the first, second, third and fourth fluid manipulation sections is controllable; wherein the geometrical profile of any one of the first, second, third and fourth fluid manipulation sections is controlled to maintain about Mach=l along at least one of the second, third and fourth fluid manipulation sections.

[0030] In some embodiments of the nozzle, the geometrical profile is controlled based on temperature of the suction fluid or HTL.

[0031] In some embodiments of the nozzle, the geometrical profile is controlled based on temperature of the HTL.

[0032] In some embodiments of the nozzle, the second fluid manipulation section comprises a different expanding configuration profile than the third manipulation section. Namely, the geometric expansion rate profile of the two sections is different.

[0033] Yet another aspect of the present disclosure provides a system for compressing gas. The system comprises a pump, a nozzle and a separation and / or collection zone. The pump is configured for pumping heat transfer liquid (HTL) to a pressure above the ambient pressure at an inlet of a nozzle. A flow path is defined along the nozzle and the nozzle is characterized according to the following in the downstream direction of said flow path, there can be other neutral parts between each section:

[0034] (i) a first converging subsonic flow section for reducing the pressure of said two-phase flow while accelerating it, reaching a supersonic flow; about Mach=l;

[0035] (ii) a first diverging supersonic flow section that reduces the pressure below ambient pressure.

[0036] (iii) a second diverging section that comprises a gas inlet for allowing suction of ambient gas into the two-phase flow, thereby obtaining a two-phase flow at a higher gas portion while maintaining the flow at about constant pressure, namely ±20% from a nominal value, here the pressure value;

[0037] (iv) a second converging section for increasing the pressure and reducing the Mach number of said two-phase flow;

[0038] (v) a third diverging section for increasing pressure of said mixture above ambient pressure.

[0039] Yet another aspect of the present disclosure provides a system for pressurizing fluid. The system comprises a pump unit for pressurizing two-phase stream above ambient pressure or the pressure of the suction fluid; and at least one nozzle according to any one of the above-described embodiments or any combination thereof that is positioned downstream said pump unit for receiving the pressurized two-phase stream through the nozzle inlet.

[0040] It is to be noted that the following system embodiments apply to both system aspects described and defined above.

[0041] In some embodiments, the system further comprises a pressurized fluid outlet; and a separation zone configured to receive the two-phase stream discharged from said at least one nozzle and separate gaseous phase from liquid phase of the two-phase stream. The pressurized suction fluid, in the form of gaseous phase of the two-phase stream, is directed to said pressurized fluid outlet to be discharged therethrough to optionally be stored in a pressurized fluid storage.

[0042] In some embodiments of the system, the nozzle outlet is configured for allowing discharge of the two-phase flow into the separation zone. In some embodiments of the system, the gas of the two-phase stream condenses at the nozzle outlet.

[0043] In some embodiments, the system is a closed loop system for the HTL or the two- phase stream.

[0044] In some embodiments of the system, the pump unit is controllable to result in a selected pressure of the two-phase stream in at least one of the first, second, third and fourth fluid manipulation sections.

[0045] In some embodiments of the system, the pump unit is controllable in response to a suction fluid temperature data indicative of a temperature of the suction fluid, e.g. the ambient temperature or the temperature of the suction fluid that is stored in its storage.

[0046] Yet another aspect of the present disclosure provides a method for compressing gas. The method comprises the following subsequent steps:

[0047] (i) providing a two-phase liquid-gas flow or stream, e.g. by pumping it, to a pressure above the ambient pressure into a first portion of a flow path;

[0048] (ii) gradually narrowing the flow path of the two-phase flow, thereby reducing the pressure of said two-phase flow and accelerating it until Mach=l or above, of said two-phase flow.

[0049] (iii) streaming two-phase flow or stream through a diverging supersonic section that reduces the pressure below the ambient while accelerating it;

[0050] (iv) allowing ambient gas, e.g. vapor, to be suctioned and mixed with the two- phase flow to obtain two-phase at higher gas fraction while gradually expanding the flow path, thereby maintaining the two-phase supersonic flow at about constant pressure, namely ±20% from a nominal value, here the pressure value;

[0051] (v) gradually narrowing the flow path, thereby increasing the pressure and reducing the Mach number until reaching Mach=l or below;

[0052] (vi) gradually expanding the subsonic flow path, thereby increasing pressure of said mixture above ambient pressure.

[0053] Yet another aspect of the present disclosure provides a method for pressurizing fluid, typically gas. The method comprises the following sequential steps:

[0054] (i) increasing pressure of a two-phase liquid-gas stream or flow, e.g. by pumping it, from a first pressure to a second pressure. The second pressure is typically above ambient pressure. It is to be noted that the gas portion, namely the void fraction of the two-phase flow in this step can be minimal and even near-zero. The two-phase liquid-gas stream that its pressure is increased from the first pressure to the second pressure comprises (1) a gas portion of either a heat transfer liquid, a working fluid (WF) or a combination of HTL and WF, and (2) a liquid portion of said HTL;

[0055] (ii) reducing pressure of the two-phase stream from said second pressure while accelerating it until reaching supersonic flow, namely Mach=l or above. In this section the gas portion, namely the void fraction of the two-phase flow increases;

[0056] (iii) expanding a flow path of the two-phase stream, which is a supersonic flow, to thereby reduce its pressure below a pressure of a suction fluid, typically gas in ambient pressure, while maintaining a supersonic flow of the two- phase stream, the suction fluid is of a same material as the two-phase flow;

[0057] (iv) allowing the suction fluid, typically gas, to flow into the two-phase stream, namely to be sucked and mixed with it to obtain two-phase flow at higher gas fraction while maintaining the two-phase supersonic stream at about constant pressure, namely ±20% from a nominal value of pressure right before said allowing, here the pressure value;

[0058] (v) gradually narrowing the flow path of the two-phase stream, thereby increasing the pressure and reducing the Mach number until reaching about Mach=l, namely ±10% from Mach=l.

[0059] (vi) expanding the flow path of the two-phase stream, thereby increasing pressure of said two-phase stream above suction fluid pressure or above ambient pressure to obtain pressurized discharged stream. The discharged stream may be either two-phase or single-phase stream, in which the gas is condensed.

[0060] It is to be noted that the following method embodiments apply to both method aspects described and defined above.

[0061] In some embodiments of the method, the discharged stream comprises a two- phase stream having a gas or vapors portion and a liquid portion. The method further comprises separating the gas portion and the liquid portion and directing or collecting the gas portion for further use. In some embodiments of the method, the pressurized discharged stream is a single-phase stream. Namely, the gas / vapor condenses along process.

[0062] In some embodiments of the method, the WF and the HTL are of the same material.

[0063] In some embodiments of the method, the two-phase stream or the HTL flows in a closed loop.

[0064] In some embodiments of the method, step (ii) comprises narrowing the flow path of said two-phase stream, e.g. passing it through a converging section of a nozzle.

[0065] In some embodiments of the method, step (iv) comprises introducing the ambient gas through an inlet. The inlet may be in the form of a conduit, a pipe, a plurality of pipes or conduits, perforations, or any other suitable solutions.

[0066] In some embodiments of the method, step (i) comprises pumping said two-phase stream from said first pressure to said second pressure, namely, using a pump to generate the initial pressure and velocity of the two-phase flow.

[0067] In some embodiments of the method, the HTL comprises at least one of water, molten salt, thermal oil, ethylene glycol, molten metal, hydro-carbonate liquids, antifreezing liquids, liquified gases, or any combination thereof.

[0068] In some embodiments of the method, the wherein the WF comprises at least one of air, argon, CO2, hydrogen, natural gas, nitrogen, organic vapors, steam, refrigerant gases, gases used in organic Rankine cycle (ORC), or any combination thereof.

[0069] In some embodiments of the method, the second pressure and a discharge pressure of the pressurized discharged stream are equal within a 10% range, i.e., the values of the two pressures differ up to 10%.

[0070] In some embodiments of the method, the HTL in the two-phase stream temperature is below about 25°C or below about 0°C along at least (ii)-(vi).

[0071] BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: Figs. 1A-1B exemplify prior art configuration of Reverse de-Laval nozzle and compressor system using the nozzle. Fig. 1A shows the nozzle; and Fig. IB shows the compressor system.

[0073] Fig. 2 exemplifies a prior art two-phase heat pump as part of an isothermal Carnot battery.

[0074] Fig- 3 is a schematic illustration of non-limiting examples of a nozzle configuration that allows two-phase flow at the inlet according to an aspect of the present disclosure. The top part of the figure shows an example that includes gas inlet to allow gas to enter into the nozzle and mix with the stream flowing therein; and the bottom part of the figure shows an example where the gas enters through an inner pipe, optionally a plurality of pipes or conduits, e.g., between 10 to 100 pipes or conduits.

[0075] Fig. 4 shows an example of T-S diagram of an isothermal cycle that includes the compressor with the new nozzle configuration, recuperator, and evaporator similar to the cycle depicted in Fig. 2.

[0076] DETAILED DESCRIPTION

[0077] The following detailed description, taken in conjunction with the accompanying drawings, will provide a better understanding of the nature and advantages of the present disclosure. The drawings are provided for illustrative purposes only and are not intended to limit the scope of the invention(s). Various modifications, alternative constructions, and equivalents may be employed without departing from the true spirit and scope of the invention as defined by the appended claims. The specific examples and embodiments described herein are exemplary in nature and are not intended to be limiting, as numerous variations and modifications will be apparent to those skilled in the art.

[0078] Fig. 3 depicts an optional two-phase compression nozzle that operates at two- phase at the inlet. The two-phase stream at the inlet comprises a liquid portion of heat transfer liquid (HTL) and a gaseous portion. The gaseous portion may include working fluid (WF), which may be the same or different material than the HTL, or a gas fraction of the HTL. The nozzle geometry includes:

[0079] 1. A first converging subsonic section that reduces the pressure and allows a portion of the WF to evaporate and / or expand. As the mixture flows velocity increases it reaches Mach=l. 2. At Mach=l, a diverging supersonic section reduces further the pressure and increases the Mach number. As the pressure drops the void fraction increases by expansion and / or by additional evaporation. These changing conditions are solved and designed according to: “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".

[0080] 3. Pressure drops and vapors are sucked into the mixing chamber. The gas or vapor- WF is sucked into the mixture through the boundaries or through a designated pipe or a plurality of pipes or conduits, e.g., between 10 to 100 pipes or conduits. The mixing chamber is diverging to allow vapor volume to be added to the flow. The calculation is done by considering the overall vapor portion (sucked and generated in the nozzle). It is to be noted that this diverging section is different than the diverging section of section 2 and serves a different purpose. In section 2, the diverging configuration results in reduction of pressure and increase of the Mach number while in section 3 the diverging configuration is designed to allow additional vapors to be sucked into the nozzle while maintaining approximately the same pressure.

[0081] 4. A converging supersonic section increases the pressure of the mixture and reduces the Mach to Mach=l . At each cross-section, the gas volume fraction is reduced and needs to be accounted for in the calculation (as in section 2).

[0082] 5. An outlet section having a subsonic diverging geometry that further increases the pressure. The outcome is a compression of a bubbly mixture.

[0083] Optionally, the compression ends with a condensation of the vapors, exiting as a single phase. Optionally the vapors and the HTL are the same liquid. Optionally one can assume a constant temperature difference between 1 and 20 degrees between the HTL and the WF. Optionally the HTL / WF temperature difference in each cross-section is calculated according to the heat transfer rate coefficient, bubble size, and the extracted heat depending on the pressure drop rate. For the isothermal process, the invested work rate equals the heat extraction rate.

[0084] In contrast to the prior art, in the converging inlet section the void (vapor or gas) fraction increases along with the reduction in the pressure. This requires solving the deLaval questions for different vapor / liquid ratios in each cross-section of that section. (For example, according to the disclosure of “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).

[0085] The specific additional vapor portion is optionally extracted from the T-S diagram of the WF. Fig. 4 depicts a T-S diagram, in this example of Butane in an isothermal compression cycle (counterclock direction from point 5-4-3-2-1-6), in a system that includes the compressor, recuperator, and evaporator as depicted in Fig. 2. Points 5-4 depict a compression at the compressor's nozzle, next the WF condenses (points 4-3) at the compressor. Optionally, for different liquids, the WF is maintained as vapor at the compressor, separated from the HTL, and flows to the condenser for condensation. Next, the WF flows to the recuperator where it cools (points 3-2) next to a flash evaporator (points 2-1) and completes evaporation at the evaporator (points 1-6), finally returning to the recuperator for heating (points 6-5). The process continues in a cyclic fashion. The drop between point 2 to point 1 is the flash evaporation and can be considered as a quasiconserved enthalpy process. At equilibrium, the vapor portion is extracted from the partial distance on the phase transition line (marked by the vapor-portion and liquid-portion on the horizontal line for each specific temperature). This additional vapor increases the void fraction and changes the Mach number and the desired De-Laval nozzle geometry at each different section of the nozzle according to the specific vapor portion and pressure at the specific cross-section of the nozzle.

[0086] A system operating on a single fluid two-phase flow is optionally condensing the vapor in the compressor. This eliminates the need for a separator and a condenser. To maintain the compressor at a constant temperature and condensation latent heat and the compression work is extracted as heat by a heat exchanger thermally connected to the compressor.

[0087] The pump is optionally connected to a variable frequency drive (VFD) for controlling the pressure at the neck to allow suction at a broad ambient temperature and sink temperature.

[0088] Optionally the neck of the nozzle is dynamically controlled (changing the diameter) according to the sink and ambient temperatures to maintain Mach=l at the neck. Optionally, other sections in the nozzle are dynamically controlled according to the sink and ambient temperatures to maintain Mach=l at the neck. Optionally, the cold (evaporator) and hot (condenser, compressor) sides of the heat pump are coupled to different sinks to deliver both hot and cooled heat-flows without being thermally coupled to the ambient. Optionally the sink is thermally coupled to the evaporator for a cooling system. Optionally the sink is thermally coupled to the compressor and condenser for heating.

[0089] Optionally, the HTL and the WF are the same liquid. Optionally the HTL and the WF are different liquids and a portion of the WF is at vapor phase at the inlet of the nozzle. In general, the nozzle is designed to be any combination of two-phase liquids at a supersonic velocity in the inlet of the nozzle. Optionally, the HTL and the WF are different liquids and a portion of the HTL is in a vapor phase at the inlet of the nozzle.

[0090] If not defined specifically otherwise, the term "about" throughout the specification should be interpreted as a deviation of ±20% of the nominal value. For example, if the value is about 10, thus it should be understood to be in the range of 8-12.

Claims

CLAIMS1. A nozzle for pressurizing fluid, comprising: a nozzle inlet for receiving a two-phase liquid-gas stream into the nozzle, the two- phase liquid-gas stream entering the nozzle inlet comprises (1) a gas portion of either a heat transfer liquid (HTL), a working fluid (WF) or a combination of HTL and WF, and (2) a liquid portion of said HTL; an outlet; a suction fluid inlet; and an arrangement of fluid manipulation sections arranged in fluid communication in a cascaded fashion and defining a flow path of said two-phase stream; wherein the arrangement comprises: a second fluid manipulation section downstream the nozzle inlet and having an expanding configuration in the direction of said flow path for reducing the two- phase stream pressure below a pressure of a suction fluid while maintaining a supersonic flow of the two-phase stream, the suction fluid is same material as the WF; a third fluid manipulation section downstream the second fluid manipulation section having an expanding configuration and is configured for receiving the two- phase stream flowing from the second fluid manipulation section at a pressure below the pressure of the suction fluid, wherein said suction fluid inlet is configured for allowing suction fluid communication between a suction fluid source, that comprises said suction fluid, and said third fluid manipulation section to be mixed with the two- phase stream to thereby obtain two-phase flow at higher gas fraction while maintaining the two-phase supersonic flow at about constant pressure; a fourth fluid manipulation section downstream the third fluid manipulation section having a narrowing configuration in the direction of said flow path for increasing the pressure and reducing the Mach number of the two-phase stream; a fifth fluid manipulation section downstream the fourth fluid manipulation section and having an expanding configuration in the direction of said flow path and configured for increasing pressure of the two-phase stream to a pressure above the suction fluid source, wherein the two-phase stream is either maintained in a two-phase state or transitions to a single-phase state at the end of the fifth fluid manipulation section; wherein said outlet is downstream the fifth fluid manipulation section or is constituted by a distal end thereof and is for discharging the two-phase flow receivedfrom the fifth fluid manipulation section, wherein the fluid mixture discharged from the outlet comprises pressurized suction fluid.

2. The nozzle of claim 1, further comprising a first fluid manipulation section downstream to the nozzle inlet and upstream the second fluid manipulation section having a narrowing configuration in a direction of said flow path for reducing pressure of the two-phase stream streamed thereinto while accelerating it until reaching supersonic flow of said two-phase stream.

3. The nozzle according to claim 2, wherein the suction fluid streamed into the first fluid manipulation section has a subsonic velocity.

4. The nozzle according to claim 1, or 2 wherein the HTL comprises at least one of water, molten salt, thermal oil, ethylene glycol, molten metal, hydro-carbonate liquids, anti-freezing liquids, liquified gases, or any combination thereof.

5. The nozzle according to any one of the preceding claims, wherein the suction fluid is gas or vapor.

6. The nozzle according to claim 4, wherein the WF comprises at least one of air, argon, CO2, hydrogen, natural gas, nitrogen, organic vapors, steam, refrigerant gases, gases used in organic Rankine cycle (ORC), or any combination thereof.

7. The nozzle according to any one of the preceding claims, wherein the suction fluid inlet comprises at least one conduit extending from an exterior thereof into the third fluid manipulation section and configured for channeling the suction fluid into the third fluid manipulation section.

8. The nozzle according to claim 6, wherein the at least one conduit is connectable to an external suction fluid source.

9. The nozzle according to any one of the preceding claims, wherein said nozzle inlet is configured to be in fluid communication with a two-phase stream source for receiving said two-phase stream in a pressure greater than ambient pressure.

10. The nozzle according to any one of the preceding claims, wherein the HTL and the WF are the same material.

11. The nozzle according to any one of the preceding claims, wherein the geometrical profile of any one of the second, third and fourth fluid manipulation sections is controllable; wherein the geometrical profile of any one of the first, second, third and fourth fluid manipulation sections is controlled to maintain about Mach=l along at least one of the second, third and fourth fluid manipulation sections.

12. The nozzle according to claim 11, wherein the geometrical profile is controlled based on temperature of the suction fluid or sink.

13. The nozzle according to any one of the preceding claims, wherein the second fluid manipulation section comprises a different expanding configuration profile than the third manipulation section.

14. A system for pressurizing fluid, comprising: a pump unit for pressurizing two-phase stream above ambient pressure; at least one nozzle according to any one of claims 1-13 positioned downstream said pump unit for receiving the pressurized two-phase stream through the nozzle inlet.

15. The system of claim 14, further comprising: a pressurized fluid outlet; and a separation zone configured to receive the two-phase stream discharged from said at least one nozzle and separate gaseous phase from liquid phase of the two-phase stream, wherein said pressurized suction fluid, in the form of gaseous phase of the two-phase stream, is directed to said pressurized fluid outlet to be discharged therethrough.

16. The system of claim 14 or 15, wherein the nozzle outlet is configured for allowing discharge of the two-phase flow into the separation zone.

17. The system according to any one of claims 14-16, wherein the gas of the two- phase stream condenses at the nozzle outlet.

18. The system according to any one of claims 14-17, being a closed loop system for the HTL or the two-phase stream.

19. The system according to any one of claims 14-18, wherein the pump unit is controllable to result in a selected pressure of the two-phase stream in at least one of the second, third and fourth fluid manipulation sections.

20. The system according to claim 19, wherein the pump unit is controllable in response to a suction fluid temperature data indicative of a temperature of the suction fluid.

21. A method for pressurizing fluid, the method comprising the following sequential steps:(i) increasing pressure of a two-phase liquid-gas stream from a first pressure to a second pressure, the two-phase liquid-gas stream that its pressure is increased from the first pressure to the second pressure comprises (1) agas portion of either a heat transfer liquid, a working fluid (WF) or a combination of HTL and WF, and (2) a liquid portion of said HTL;(ii) reducing pressure of the two-phase stream from said second pressure while accelerating it until reaching supersonic flow;(iii) expanding a flow path of the two-phase stream to thereby reduce its pressure below a pressure of a suction fluid while maintaining a supersonic flow of the two-phase stream, the suction fluid is of a same material as the two-phase flow;(iv) allowing the suction fluid to flow into the two-phase stream to obtain two- phase flow at higher gas fraction while maintaining the two-phase supersonic stream at about constant pressure;(v) gradually narrowing the flow path of the two-phase stream, thereby increasing the pressure and reducing the Mach number;(vi) expanding the flow path of the two-phase stream, thereby increasing pressure of said two-phase stream above suction fluid pressure or above ambient pressure to obtain pressurized discharged stream.

22. The method of claim 21, wherein the discharged stream comprises a two-phase stream having a gas portion and a liquid portion; wherein the method further comprising separating the gas portion and the liquid portion and directing the gas portion for further use.

23. The method of claim 21 or 22, wherein the pressurized discharged stream is a single-phase stream.

24. The method of any one of claims 21-23, wherein the WF and the HTL are of the same material.

25. The method according to any one of claims 21-24, wherein the two-phase stream flows in a closed loop.

26. The method according to any one of claims 21-25, wherein (ii) comprises narrowing the flow path of said two-phase stream.

27. The method according to any one of claims 21-26, wherein the (iv) comprises introducing the ambient gas through an inlet.

28. The method according to any one of claims 21-27, wherein (i) comprises pumping said two-phase stream from said first pressure to said second pressure.

29. The method according to any one of claims 21-28, wherein the HTL comprises at least one of water, molten salt, thermal oil, ethylene glycol, molten metal, hydrocarbonate liquids, anti-freezing liquids, liquified gases, or any combination thereof.

30. The method according to any one of claims 21-29, wherein the wherein the WF comprises at least one of air, argon, CO2, hydrogen, natural gas, nitrogen, organic vapors, steam, refrigerant gases, gases used in organic Rankine cycle (ORC), or any combination thereof.

31. The method according to any one of claims 21-30, wherein the second pressure and a discharge pressure of the pressurized discharged stream are equal within a 10% range.

32. The method according to any one of claims 21-31, wherein the two-phase stream temperature is below 25°C.

Images