Fluid accelerator apparatus

Abstract

A fluid accelerator for mixing and pumping one or more fluids through a system. The fluid accelerator includes an adjustable flow through needle that leverages the Coandă effect to lower the required mass flow rate of a motive fluid while increasing the lift pressure of a suction fluid entrained by the motive fluid in the fluid accelerator. The needle can be adjusted within a first motive fluid channel to address changing flow conditions. The needle includes a second motive fluid channel that redirects the flow of a portion of the motive fluid within the first motive fluid channel through the needle into a mixing section, which creates the Coandă effect in the mixing section.

Description

FLUID ACCELERATOR APPERATUSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] None.FIELD OF THE DISCLOSURE

[0002] The present disclosure generally relates to a fluid accelerator for mixing and pumping one or more fluids through a system. More particularly, the fluid accelerator includes an adjustable flow through needle that leverages the Coanda effect to lower the required mass flow rate of a motive fluid while increasing the lift pressure of a suction fluid entrained by the motive fluid in the fluid accelerator. The needle can be adjusted within a first motive fluid channel to address changing flow conditions. The needle includes a second motive fluid channel that redirects the flow of a portion of the motive fluid within the first motive fluid channel through the needle into a mixing section, which creates the Coanda effect in the mixing section.BACKGROUND

[0003] Entrainment devices for converting kinetic energy into pressure recovery exist in various applications and are generally known as ejectors, injectors, jet pumps or thermocompressors. The operation of such devices is generally controlled by a fixed nozzle or an adjustable needle within a fixed nozzle.

[0004] Referring now to FIG. 1, a cross-section view of a conventional ejector 100 is illustrated with a fixed de Laval nozzle 102. A high-pressure fluid enters the ejector 100 through a motive inlet port 101 and is expanded using the fixed nozzle 102. The expanded fluid entrains the suction of another low-pressure fluid through a suction inlet port 103 into a mixing section 105. As the two fluids (which may be the same composition / phase or different1008643.00090068307384compositions / phases) are mixed, the mixed fluid approaches supersonic speed before entering a diffuser 109. As the mixed fluid passes through the diffuser 109, its velocity will rapidly decrease. The kinetic energy is then converted to pressure energy, resulting in a further pressure increase and velocity decrease. When the pressure at an outlet 111 of the ejector 100 approaches a state of critical back pressure, the ejector 100 will enter a choking mode where backflow occurs. As a result, enhancements have been made to the design of the fixed nozzle 102.

[0005] Referring now to FIG. 2, a cross-section view of a conventional ejector 200 is illustrated with an adjustable needle 205 within a fixed nozzle 206. A high-pressure fluid enters the ejector 200 through a motive inlet port 201 and flows through a channel 213 in the fixed nozzle 206 and is expanded by the adjustable needle 205. The expanded fluid entrains the suction of another low-pressure fluid through a suction inlet port 203 into a mixing section 207. As the two fluids are mixed, the mixed fluid approaches supersonic speed before entering a diffuser 211. The adjustable needle 205 facilitates flow control of the high-pressure fluid as it passes through channel 213 in the fixed nozzle 206. Because the velocity of the mixed fluid will decrease as its passes through the diffuser 211, the back pressure will increase and lower the lift pressure needed to entrain the low-pressure fluid into the suction inlet port 203.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The detailed description is described below with reference to the accompanying drawing, in which like elements are referenced with like reference numbers, and in which:

[0007] FIG. 1 is a cross-section view illustrating a conventional ejector with a fixed nozzle.

[0008] FIG. 2 is a cross-section view illustrating a conventional ejector with an adjustable needle within a fixed nozzle.2008643.00090068307384

[0009] FIG. 3A is a cross-section view illustrating a fluid accelerator with an adjustable flow through needle.

[0010] FIG. 3B is an enlarged view illustrating the area 3B circled in FIG. 3A.

[0011] FIG. 4A is a plan view illustrating the adjustable flow through needle in FIG. 3A.

[0012] FIG. 4AB is a cross-section view illustrating the adjustable flow through needle in FIG. 4A along A- A.

[0013] FIG. 5A is a cross-plot illustrating modeled mass flow rate as a function of time for a conventional ejector and the fluid accelerator.

[0014] FIG. 5B is a cross-plot illustrating modeled pressure as a function of time for a conventional ejector and the fluid accelerator.

[0015] FIG. 6A is a cross-plot illustrating motive fluid density for a conventional ejector.

[0016] FIG. 6B is a cross-plot illustrating motive fluid density for the fluid accelerator.

[0017] FIG. 7A is a cross-plot illustrating motive fluid density and motive fluid flow path (with arrows) for a conventional ejector.

[0018] FIG. 7B is a cross-plot illustrating motive fluid density and motive fluid flow path (with arrows) for the fluid accelerator.

[0019] FIG. 8 A is a cross-plot illustrating motive fluid velocity (m / s) for a conventional ejector.

[0020] FIG. 8B is a cross-plot illustrating motive fluid velocity (m / s) for the fluid accelerator.

[0021] FIG. 9A is a cross-plot illustrating motive fluid mass fraction of CO2 vapor for a conventional ejector.3008643.00090068307384

[0022] FIG. 9B is a cross-plot illustrating motive fluid mass fraction of CO2 vapor for the fluid accelerator.

[0023] FIG. 10A is a cross-plot illustrating motive fluid mass flux (m2 / s2) for a conventional ejector.

[0024] FIG. 10B is a cross-plot illustrating motive fluid mass flux (m2 / s2) for the fluid accelerator.DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

[0025] The subject matter of the present disclosure is described with specificity, however, the description itself is not intended to limit the scope of the disclosure. The subject matter thus, might also be embodied in other ways, to include different structures, steps and / or combinations similar to and / or fewer than those described herein, in conjunction with other present or future technologies. Although the term “step” may be used herein to describe different elements of methods employed, the term should not be interpreted as implying any particular order among or between various steps herein disclosed unless otherwise expressly limited by the description to a particular order. Other features and advantages of the disclosed embodiments will be or will become apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional features and advantages be included within the scope of the disclosed embodiments. Further, the illustrated figures described herein are only exemplary and are not intended to assert or imply any limitation with regard to the environment, architecture, design, or process in which different embodiments may be implemented. To the extent that temperatures, pressures and other dimensions are referenced in the following description, those conditions are merely illustrative and are not meant to limit the disclosure. All streams described herein are carried by physical lines.4008643.00090068307384

[0026] The present disclosure overcomes the disadvantages of the prior art with a fluid accelerator, which includes an adjustable flow through needle that leverages the Coanda effect to lower the required mass flow rate of a motive fluid while increasing the lift pressure of a suction fluid entrained by the motive fluid in the accelerator. The needle can be adjusted within a first motive fluid channel to address changing flow conditions. The needle includes a second motive fluid channel that redirects the flow of a portion of the motive fluid within the first motive fluid channel through the needle into a mixing section, which creates the Coanda effect in the mixing section.

[0027] In one embodiment, a fluid accelerator is disclosed, which comprises: i) a body having: a) a first end; b) an open second end; c) a longitudinal passage fluidly connected to the second end; d) a motive inlet port fluidly connected to the longitudinal passage; e) a suction inlet port fluidly connected to the longitudinal passage by a suction fluid channel positioned between the motive inlet port and the second end; and f) a nozzle positioned in the longitudinal passage between the motive inlet port and the second end, the nozzle separating fluid communication between the motive inlet port and the suction inlet port in a section of the longitudinal passage between the motive inlet port and an outlet of the nozzle forming a first motive fluid channel; and ii) an adjustable needle positioned in the longitudinal passage and configured to partially extend through an outlet of the nozzle, the adjustable needle having a first end, an open second end, and a longitudinal passage forming a second motive fluid channel fluidly connecting the first motive fluid channel and the second end of the needle through a plurality of openings positioned between the first end of the needle and the second end of the needle.

[0028] In another embodiment, a method for entraining fluids is disclosed, which comprises: i) directing a motive fluid having a motive fluid pressure through a first motive fluid5008643.00090068307384channel and an outlet of a nozzle; ii) directing a suction fluid having a suction fluid pressure lower than the motive fluid pressure through a suction fluid channel; iii) redirecting a portion of the motive fluid within the first motive fluid channel through a second motive fluid channel extending through the outlet of the nozzle; and iv) entraining the suction fluid with at least one of the motive fluid and the portion of the motive fluid.

[0029] Referring now to FIGS. 3A-3B, a cross-section view of a fluid accelerator 300 with an adjustable flow through needle 302 is illustrated in FIG. 3A and an enlarged view of the area circled in FIG. 3A is illustrated in FIG. 3B. The fluid accelerator 300 includes a body 304 with a first end 306 and an open second end 308 that functions as a discharge outlet for a mixed fluid 309. The first end 306 is preferably threaded for receipt of the flow through needle 302, which is also threaded. The second end 308 is preferably threaded for connecting the fluid accelerator 300 to a system and pumping the mixed fluid 309 through the system. The body 304 includes a longitudinal passage 310 from the first end 306 to the second end 308. The body 304 further includes a motive inlet port 312 fluidly connected to the longitudinal passage 310 and a suction inlet port 314 fluidly connected to the longitudinal passage 310 by a suction fluid channel 311 positioned between the suction inlet port 314 and the second end 308. The motive inlet port 312 is preferably threaded for connection to a motive fluid line adapted to carry a high-pressure motive fluid 313. The suction fluid inlet port 314 is preferably threaded for connection to a suction fluid line adapted to carry a low-pressure suction fluid 315. The high-pressure motive fluid 313 and the low-pressure suction fluid 315 can be the same fluid in different phases or different fluids with the same phase as long as the high-pressure motive fluid 313 enters the motive inlet port 312 at a higher pressure than the low-pressure suction fluid 315 entering the suction fluid inlet port 314.6008643.00090068307384

[0030] The body 304 forms a converging conical nozzle 316 positioned in the longitudinal passage 310 between the motive inlet port 312 and the second end 308. The nozzle 316 separates fluid communication between the motive inlet port 312 and the suction inlet port 314 in a section of the longitudinal passage 310 between the motive inlet port 312 and an outlet 318 of the nozzle 316 forming a first motive fluid channel 320. The flow through needle 302 is positioned in the longitudinal passage 310 and is configured to extend through and open or close the outlet 318 of the nozzle 316 by adjusting the threaded connection with the first end 306 of the body 304. The flow through needle 302 may thus, be adjusted to control flow of the high-pressure motive fluid 313 as it passes from the motive inlet port 312 through the first motive fluid channel 320 and the outlet 318 of the nozzle 316. Alternatively, other means may be employed for securing and adjusting the flow through needle 302 within the longitudinal passage 310 without a threaded connection with the first end 306 of the body 304. The flow through needle 302 includes a first end 322, an open second end 324 and a longitudinal passage forming a second motive fluid channel 326 fluidly connecting the first motive fluid channel 320 and the second end 324 of the flow through needle 302 through a plurality of angled openings 328 positioned between the first end 322 and the second end 324.

[0031] Referring now to FIGS. 4A-4B, the adjustable flow through needle in FIG. 3A is illustrated in a plan view (FIG. 4A) and a cross-section view (FIG. 4B). The plurality of angled openings 328 are preferably positioned closer to the second end 324 than the first end 322. The flow through needle 302 forms a converging conical nozzle 332 between the plurality of angled openings 328 and the second end 324. The converging nozzle 332 is configured to extend sufficiently through the outlet 318 of the nozzle 316 into the mixing section 340 to promote the Coanda effect. An outside diameter 317 of the flow through needle 302 is thus larger than the7008643.00090068307384outlet 318 of the nozzle 316 to enable the flow through needle 302 to open or close the outlet 318 of the nozzle 316 by adjusting the threaded connection with the first end 306 of the body 304.

[0032] In operation, a high-pressure motive fluid 313 enters the fluid accelerator 300 through the motive inlet port 312. The motive fluid 313 proceeds through the first motive fluid channel 320, the outlet 318 of the nozzle 316 and into a mixing section 340 of the longitudinal passage 310. A portion of the motive fluid 313 in the first motive fluid channel 320 is redirected through the plurality of angled openings 328, the second motive fluid channel 326, the second end 324 of the flow through needle 302 and into the mixing section 340. The plurality of angled openings 328 and a pressure differential between the first motive fluid channel 320 and the second motive fluid channel 326 facilitate redirecting a portion of the motive fluid 313 from the first motive fluid channel 320 into the second motive fluid channel 326. As the flow through needle 302 is adjusted toward the mixing chamber 340 to restrict the motive fluid 313 flow from the first motive fluid channel 320 through the outlet 318 of the nozzle 316, the motive fluid 313 redirected from the first motive fluid channel 320 into the second motive fluid channel 326 increases. Conversely, the motive fluid 313 redirected from the first motive fluid channel 320 into the second motive fluid channel 326 decreases as the flow through needle 302 is adjusted away from the mixing chamber 340 to expand the motive fluid 313 flow from the first motive fluid channel 320 through the outlet 318 of the nozzle 316.

[0033] A low-pressure suction fluid 315 enters the fluid accelerator 300 through the suction inlet port 314. As a result of lift pressure, the motive fluid 313 passing through the first motive fluid channel 320 into a mixing section 340 and / or the motive fluid 313 passing through the second motive fluid channel 326 into the mixing section 340 entrains the low-pressure suction fluid 315 from the suction channel 311 into the mixing section 340. The greater the pressure8008643.00090068307384differential between the high-pressure motive fluid 313 and the low-pressure suction fluid 315, the greater the lift pressure and entrainment ratio. The motive fluid 313 and the suction fluid 315 are mixed as they pass through the mixing section 340 at a high velocity to form the mixed fluid 309. The mixed fluid 309 continues through a section of the longitudinal passage 310 that functions as a diffuser 342 and exits the second end 308 of the fluid accelerator 300 that functions as a discharge outlet for the mixed fluid 309. Because the diffuser 342 is conical in design, the mixed fluid 309 is expanded as it passes through the diffuser 342, which lowers the velocity and pressure of the mixed fluid 309.

[0034] Compared to conventional ejectors, the unique design of the adjustable flow through needle 302 leverages the Coanda effect to lower the required mass flow rate of the motive fluid while increasing the lift pressure of the suction fluid entrained by the motive fluid. A computational fluid dynamics (CFD) model was developed to compare the operational efficiency of the conventional ejector illustrated in FIG. 2 and the fluid accelerator illustrated in FIGS. 3A- 3B. The CFD model was developed using experimental data that was based on the multi-stage refrigeration system described in US Patent No. 10,533,793, calibrated to a transcritical CO2 ejector cycle and validated. The results are illustrated in FIGS. 5A / 5B through 10A / 10B and are summarized in Table 1 below. In FIGS. 6A / 6B through 10A / 10B, the motive fluid values are plotted using a grey scale along x / d which represents the distance measured along the horizontal axis divided by the diameter of the mixing chamber and y / d which represents the distance measured along the vertical axis from a centerline of the mixing chamber divided by its diameter.

[0035] As illustrated in Table 1, the modeled suction (lift) pressure is 2% higher with the fluid accelerator compared to the conventional ejector and the modeled motive mass flow rate is reduced by greater than 20%. The entrainment ratio is defined as the mass flow of the suction9008643.00090068307384divided by the mass flow of the motive and the pressure lift ratio is defined as the ratio of the discharge pressure to the suction pressure.Conventional Ejector Fluid AcceleratorMotive Mass Flow, g / s 57.36 45.26Motive Pressure, bar 63.48 63.48Suction Mass Flow, g / s 9.853 9.853Suction Pressure, bar 25.78 26.24Outlet Quality 0.43 0.42Entrainment Ratio 0.1717 0.2176Pressure Lift Ratio 1.176 1.15TABLE 1

[0036] In FIGS. 5A-5B, the cross-plots illustrate the modeled mass flow rate and pressure, respectively, as a function of time for the conventional ejector and the fluid accelerator. The modeled mass flow rate and pressure plots for the conventional ejector fall substantially within the experimental data (measured in experiment) range that was used. A simple comparison demonstrates that a lower mass flow rate and suction pressure are required for the fluid accelerator to achieve the same outlet conditions.

[0037] In FIGS. 6A-6B, the cross-plots illustrate the motive fluid density for the conventional ejector and the fluid accelerator, respectively, as the motive fluid flows around the adjustable needle 205 and through the nozzle 206 in FIG. 6A and as the motive fluid flows around and through the flow-through needle 302 and through the nozzle 316 in FIG. 6B. Likewise, FIGS. 7A-7B plot the motive fluid density for the conventional ejector and the fluid accelerator, respectively, and further illustrate (with arrows) the motive fluid flow path as it flows around the adjustable needle 205 and through the nozzle 206 in FIG. 6A and as it flows around and through the flow-through needle 302 and through the nozzle 316 in FIG. 6B. The fluid accelerator creates10008643.00090068307384a significantly longer motive fluid jet stream in FIG. 7B at x / d > 15 (preventing breakup) compared to the motive fluid jet stream created by the conventional ejector in FIG. 7A at x / d=10.

[0038] In FIGS. 8A-8B, the cross-plots illustrate the motive fluid velocity (m / s) for the conventional ejector and the fluid accelerator, respectively, as the motive fluid flows around the adjustable needle 205 and through the nozzle 206 in FIG. 8A and as the motive fluid flows around and through the flow-through needle 302 and through the nozzle 316 in FIG. 8B. FIG. 8B illustrates a higher motive fluid velocity at x / d=0 to 10 for the fluid accelerator, compared to the conventional ejector in FIG. 8A, which increases the lift pressure of the suction fluid entrained by the motive fluid.

[0039] In FIGS. 9A-9B, the cross-plots illustrate the motive fluid mass fraction of CO2 vapor for the conventional ejector and the fluid accelerator, respectively, as the motive fluid flows around the adjustable needle 205 and through the nozzle 206 in FIG. 9A and as the motive fluid flows around and through the flow-through needle 302 and through the nozzle 316 in FIG. 9B. FIG. 9B illustrates the motive fluid jet stream created by the Coanda effect for the fluid accelerator, which extends to x / d=15, accelerates the CO2 and causes a phase change in both the motive fluid and the suction fluid.

[0040] In FIGS. 10A-10B, the cross-plots illustrate the motive fluid mass flux (m2 / s2) for the conventional ejector and the fluid accelerator, respectively, as the motive fluid flows around the adjustable needle 205 and through the nozzle 206 in FIG. 10A and as the motive fluid flows around and through the flow-through needle 302 and through the nozzle 316 in FIG. 10B. FIG. 10B illustrates a longer motive fluid jet stream extending to x / d=15 for the fluid accelerator compared to the motive fluid jet stream that breaks up at about x / d=10 for the conventional ejector in FIG. 10A11008643.00090068307384

[0041] While the present disclosure has been described in connection with presently preferred embodiments, it will be understood by those skilled in the art that it is not intended to limit the disclosure of those embodiments. The fluid accelerator may be implemented in different systems (e.g., refrigeration, water purification, air diffusers, j et pumps and rocket propulsion) and adjusted under changing flow conditions to improve the operation and control of each system. It is therefore contemplated that various alternative embodiments and modifications may be made to the disclosed embodiments without departing from the spirit and scope of the disclosure defined by the appended claims and equivalents thereof.12008643.00090068307384

Claims

CLAIMS1. A fluid accelerator, which comprises: a body having: a first end; an open second end; a longitudinal passage fluidly connected to the second end; a motive inlet port fluidly connected to the longitudinal passage; a suction inlet port fluidly connected to the longitudinal passage by a suction fluid channel positioned between the motive inlet port and the second end; and a nozzle positioned in the longitudinal passage between the motive inlet port and the second end, the nozzle separating fluid communication between the motive inlet port and the suction inlet port in a section of the longitudinal passage between the motive inlet port and an outlet of the nozzle forming a first motive fluid channel; and an adjustable needle positioned in the longitudinal passage and configured to partially extend through an outlet of the nozzle, the adjustable needle having a first end, an open second end, and a longitudinal passage forming a second motive fluid channel fluidly connecting the first motive fluid channel and the second end of the needle through a plurality of openings positioned between the first end of the needle and the second end of the needle.

2. The fluid accelerator of claim 1, wherein the nozzle is conical.

3. The fluid accelerator of claim 1, wherein a portion of the adjustable needle between the plurality of openings and the open second end is conical.

4. The fluid accelerator of claim 1, wherein each of the plurality of openings is angled between 0 and 45 degrees relative to an axis of the adjustable needle.13008643.000900683073845. The fluid accelerator of claim 1, wherein the first end of the adjustable needle is threadedly connected to the first end of the body.

6. The fluid accelerator of claim 3, wherein a portion of the adjustable needle between the plurality of openings and the open second end is positioned through the nozzle outlet.

7. The fluid accelerator of claim 6, wherein a portion of the adjustable needle between the plurality of openings and the open second end is positioned through the nozzle outlet and the conical portion of the adjustable needle seals the nozzle outlet.

8. A method for entraining fluids, which comprises: directing a motive fluid having a motive fluid pressure through a first motive fluid channel and an outlet of a nozzle; directing a suction fluid having a suction fluid pressure lower than the motive fluid pressure through a suction fluid channel; redirecting a portion of the motive fluid within the first motive fluid channel through a second motive fluid channel extending through the outlet of the nozzle; and entraining the suction fluid with at least one of the motive fluid and the portion of the motive fluid.

9. The method of claim 8, further comprising controlling a flow of the motive fluid through the first motive fluid channel by restricting the flow of the motive fluid through the outlet of the nozzle.

10. The method of claim 9, further comprising controlling a flow of the portion of the motive fluid redirected through the second motive fluid channel by restricting the flow of the motive fluid through the outlet of the nozzle.14008643.0009006830738411 . The method of claim 8, further comprising increasing a lift pressure of the suction fluid by adjusting a position of the second motive fluid channel relative to the outlet of the nozzle.15008643.00090068307384

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