Pressure exchange ejector

Abstract

The present application provides a kind of pressure exchange ejector, including ejector shell, adjustable supersonic nozzle driven by first electric push rod is equipped in the ejector shell, and adjustable cone driven by second electric push rod is equipped in the ejector shell, the adjustable cone is arranged in adjustable supersonic nozzle relative to the end of second electric push rod and is slidably connected with adjustable supersonic nozzle, the mixing chamber entrance and the mixing chamber outlet are further equipped in the ejector shell, the first conical part is set on adjustable supersonic nozzle corresponding to the mixing chamber entrance, and the second conical part is set on adjustable cone corresponding to the mixing chamber outlet;The present application has the following beneficial effects: the present application can adjust the position of adjustable supersonic nozzle and adjustable cone in real time to further adjust key area, maintain the original pressure recovery capability while maintaining a higher entrainment coefficient, i.e. entrainment coefficient is adaptive, can solve the problem of low performance and efficiency of ejector under non-design condition.

Description

Technical Field

[0001] This invention relates to the field of ejector technology, and in particular to a pressure-exchange ejector. Background Technology

[0002] An ejector is a fluid machinery device where a high-pressure fluid, passing through the ejector nozzle, forms a high-speed jet that exchanges momentum with a low-pressure fluid, increasing the pressure of the low-pressure fluid to medium or even high pressure. The high-pressure fluid is called the main ejector fluid (also known as the working fluid or primary fluid); the low-pressure fluid is called the entrained fluid (also known as the ejector fluid or secondary fluid); the fluid resulting from their mixture is called the mixed fluid. The ejection coefficient is a key indicator of ejector performance, defined as the ratio of the mass flow rate of the entrained fluid to the mass flow rate of the main ejector fluid. In the compressor's operating conditions, the medium is... Natural gas can provide a working gas pressure and the required ejector outlet gas pressure, which is on the order of 4 MPa. The required ejector outlet gas pressure cannot be lower than a certain value, and the pressure loss must be small. In addition, the natural gas venting pressure of the compressor dry gas seal stage is on the order of 0.1 MPa, which is at least ten times higher than the previous two pressures. That is, the compression ratio and expansion ratio are very large. The problem is that the energy loss, i.e. the pressure loss, caused by the complex action of the supersonic mixing process is large. For a large compression ratio, it is also difficult to reach the required ejector outlet gas pressure through the diffuser chamber.

[0003] The operating conditions of the compressor will change, and the mass flow rate and pressure of the vented natural gas in the dry gas seal stage will also change accordingly. Depending on the different operating speeds of the compressor and the different seals of different circuits, the expected venting volume of the natural gas in the dry gas seal stage varies within a certain range. For traditional constant area ejectors, the ejection performance is constant when the operating conditions remain unchanged under the pressure setting. However, when the operating conditions change, the venting flow rate of the natural gas in the dry gas seal stage will change with the operating speed of the compressor, and the ejection performance of the ejector will change significantly. It is difficult to ensure that the vented natural gas can be recovered to the greatest extent and achieve a large ejection coefficient and high recovery efficiency. The above problems cannot be solved by using traditional ejectors. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a pressure exchange ejector to solve the problem that the prior art cannot guarantee the maximum recovery of vented natural gas.

[0005] To achieve the above and other related objectives, the present invention provides the following technical solution:

[0006] A pressure-exchange ejector includes an ejector housing. The ejector housing contains an adjustable supersonic nozzle driven by a first electric actuator and an adjustable cone driven by a second electric actuator. The end of the adjustable cone opposite to the second electric actuator passes through the adjustable supersonic nozzle and is slidably connected to it. The ejector housing also contains a mixing chamber inlet and a mixing chamber outlet. The adjustable supersonic nozzle has a first conical portion corresponding to the mixing chamber inlet, the adjustable cone has a second conical portion corresponding to the mixing chamber outlet, and the adjustable cone also has a third conical portion corresponding to the throat and outlet of the adjustable supersonic nozzle.

[0007] In one embodiment of the present invention, the ejector housing includes a first housing and a second housing integrally formed with the first housing. The first housing is provided with a first mounting chamber and an intake chamber in sequence. The second housing is provided with a mixing chamber, a diffuser chamber, an exhaust chamber and a second mounting chamber in sequence. The connection between the first housing and the second housing is the inlet of the mixing chamber. The first electric push rod is located in the first mounting chamber and is installed in the first housing through a first adjusting block. The second electric push rod is located in the second mounting chamber and is installed in the second housing through a second adjusting block.

[0008] In one embodiment of the present invention, a first slider is provided at the connection between the first electric push rod and the adjustable supersonic nozzle, and is slidably connected to the first mounting chamber. A second slider is provided at the connection between the second electric push rod and the adjustable cone, and is slidably connected to the second mounting chamber. In this technical solution, the adjustable supersonic nozzle can move more stably under the sliding action of the first slider in the first mounting chamber, and the adjustable cone can move more stably under the sliding action of the second slider in the second mounting chamber.

[0009] In one embodiment of the present invention, the adjustable cone includes a first cone located within a second housing and a second cone located within a first housing. The second cone is disposed on the first cone and integrally formed with the first cone. The third cone is disposed on the second cone and integrally formed with the second cone. The first cone and the second cone are connected by a bearing. A rotor is sleeved on the surface of the bearing. A plurality of blades are uniformly distributed circumferentially on the circumferential side of the rotor. In this technical solution, the rotation of the rotor will drive the blades to rotate, thereby enabling the ejected gas and the main ejected gas ejected from the adjustable supersonic nozzle to be mixed, thus improving the mixing efficiency.

[0010] In one embodiment of the present invention, the first housing is provided with a first air inlet pipe communicating with the inhalation chamber and a second air inlet pipe communicating with the first mounting chamber. The adjustable supersonic nozzle is provided with an air inlet corresponding to the second air inlet pipe. A low-pressure air inlet pipe is connected to the first air inlet pipe and a high-pressure air inlet pipe is connected to the second air inlet pipe.

[0011] In one embodiment of the present invention, a first pressure gauge and a first flow meter are sequentially provided on the low-pressure intake pipe, and a first control valve for controlling the opening and closing of the low-pressure intake pipe is also installed on the low-pressure intake pipe. In this technical solution, the first pressure gauge and the first flow meter can detect the pressure and flow rate of the injected gas in the low-pressure intake pipe.

[0012] In one embodiment of the present invention, the high-pressure intake pipeline includes a first high-pressure intake branch and a second high-pressure intake branch connected to each other. A second pressure gauge and a second flow meter are sequentially provided on the first high-pressure intake branch. A second control valve for controlling the on / off state of the first high-pressure intake branch is provided on the first high-pressure intake branch. A first pressure regulating valve and a second pressure regulating valve are sequentially provided on the second high-pressure intake branch. An outlet pipe connected to the outlet chamber and the second high-pressure intake branch is also provided on the second housing. In this technical solution, the second pressure gauge and the second flow meter can detect the pressure and flow rate of the main ejector gas in the first high-pressure intake branch.

[0013] In one embodiment of the present invention, a first flange is installed at the end of the first housing opposite to the second housing, a second flange is sleeved on the surface of the first housing facing the second housing and located between the first air inlet pipe and the second air inlet pipe, a third flange is installed at the end of the second housing opposite to the first housing, and a fourth flange is installed on the first air inlet pipe, the second air inlet pipe and the air outlet pipe.

[0014] As described above, the pressure exchange ejector of the present invention has the following beneficial effects:

[0015] This invention utilizes an adjustable supersonic nozzle and an adjustable cone, driven by an electric push rod, to move relative to or in opposite directions. This allows for changes in the area of ​​the throat, outlet, mixing chamber inlet, and outlet of the adjustable supersonic nozzle. By adjusting the positions of the adjustable supersonic nozzle and the adjustable cone in real time, key areas can be adjusted. This maintains the original pressure recovery capability while preserving a high ejector coefficient, i.e., an adaptive ejector coefficient. This solves the problem of low ejector performance and efficiency under non-design conditions, thereby ensuring maximum recovery of vented natural gas. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the pressure exchange ejector disclosed in an embodiment of the present invention;

[0017] Figure 2 This is a top-view perspective view of the pressure exchange ejector disclosed in an embodiment of the present invention;

[0018] Figure 3This is a frontal sectional vertical schematic diagram of the pressure exchange ejector disclosed in an embodiment of the present invention;

[0019] Figure 4 This is a front cross-sectional view of the first housing in the pressure exchange ejector disclosed in an embodiment of the present invention;

[0020] Figure 5 The pressure exchange ejector disclosed in the embodiments of the present invention Figure 4 Enlarged view of point A in the middle;

[0021] Figure 6 This is a front cross-sectional view of the second housing in the pressure exchange ejector disclosed in an embodiment of the present invention;

[0022] Figure 7 The pressure exchange ejector disclosed in the embodiments of the present invention Figure 6 Enlarged view of point B in the middle;

[0023] Figure 8 This is a three-dimensional schematic diagram of the adjustable cone in the pressure exchange ejector disclosed in an embodiment of the present invention;

[0024] Figure 9 This is a three-dimensional schematic diagram of the rotor in the pressure exchange ejector disclosed in an embodiment of the present invention;

[0025] Figure 10 This is a front cross-sectional schematic diagram of the mixing chamber and the diffuser chamber in the pressure exchange ejector disclosed in an embodiment of the present invention;

[0026] Figure 11 This is a schematic diagram of the control flow in the pressure exchange ejector disclosed in an embodiment of the present invention.

[0027] Component designation explanation

[0028] 1. Ejector housing; 101. First housing; 102. Second housing; 2. First inlet pipe; 3. Second inlet pipe; 4. Outlet pipe; 5. First flange; 6. Second flange; 7. Third flange; 8. Fourth flange; 9. Low-pressure inlet pipe; 10. First pressure gauge; 11. First flow meter; 12. First control valve; 13. First high-pressure inlet branch; 14. Second high-pressure inlet branch; 15. Second pressure gauge; 16. Second flow meter; 17. Second control valve; 18. First pressure regulating valve; 19. Second pressure regulating valve; 20. First adjusting block; 21. First electric push rod; 2 2. Adjustable supersonic nozzle; 23. Adjustable cone; 2301. First cone; 2302. Second cone; 24. Second electric push rod; 25. Second adjusting block; 26. First mounting chamber; 27. Inhalation chamber; 28. First slider; 29. ​​Air inlet; 30. First conical section; 31. Throat; 32. Third conical section; 33. Air outlet; 34. Mixing chamber inlet; 35. Diffusion chamber; 36. Air outlet chamber; 37. Second slider; 38. Second mounting chamber; 39. Rotor; 40. Mixing chamber; 41. Mixing chamber outlet; 42. Second conical section; 43. Bearing; 44. Blade. Detailed Implementation

[0029] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. It should be noted that, unless otherwise specified, the following embodiments and features described herein can be combined with each other.

[0030] Please see Figures 1 to 9 This invention provides a pressure exchange ejector, comprising an ejector housing 1. The ejector housing 1 contains an adjustable supersonic nozzle 22 driven by a first electric push rod 21 and an adjustable cone 23 driven by a second electric push rod 24. The adjustable cone 23 is a complex conical column. The end of the adjustable cone 23 opposite to the second electric push rod 24 passes through the adjustable supersonic nozzle 22 and is slidably connected to it. A groove is provided at the connection between the adjustable supersonic nozzle 22 and the first slider 28, allowing for slidable connection with the adjustable cone 23. The ejector housing 1 also contains a mixing chamber inlet 34 and a mixing chamber outlet 41. The adjustable supersonic nozzle 22 has a first conical portion 30 corresponding to the mixing chamber inlet 34, and the adjustable cone 23 has a second conical portion 42 corresponding to the mixing chamber outlet 41. The mixing chamber 40 is divided into a contraction section and a straight section, with the straight section located at the mixing chamber outlet 41. For details, please refer to [link to relevant documentation]. Figure 10 The adjustable cone 23 is also provided with a third cone-shaped part 32 corresponding to the throat 31 and the air outlet 33 of the adjustable supersonic nozzle 22.

[0031] The ejector housing 1 includes a first housing 101 and a second housing 102 integrally formed with the first housing 101. The first housing 101 is provided with a first mounting chamber 26 and a suction chamber 27 in sequence. The second housing 102 is provided with a mixing chamber 40, a diffuser chamber 35, an exhaust chamber 36 and a second mounting chamber 38 in sequence. The first mounting chamber 26 and the suction chamber 27 are arranged in sequence along the length of the first housing 101. The mixing chamber 40, the diffuser chamber 35, the exhaust chamber 36 and the second mounting chamber 38 are arranged in sequence along the length of the second housing 102. The connection between the first housing 101 and the second housing 102 is the mixing chamber inlet 34. The first electric push rod 21 is located in the first mounting chamber 26 and is installed in the first housing 101 through the first adjusting block 20. The second electric push rod 24 is located in the second mounting chamber 38 and is installed in the second housing 102 through the second adjusting block 25.

[0032] The adjusting block allows for the adjustment of the positions of the first electric push rod 21 and the second electric push rod 24 during installation. This enables fine-tuning of the positions of the adjustable supersonic nozzle 22 and the adjustable cone 23 in the initial state of the ejector. Combined with the linear displacement encoder built into the electric push rod, the adjustment of both is performed according to the design ratio, ensuring the ejection effect and achieving self-adjustment of the ejection coefficient. A first slider 28, slidably connected to the first mounting chamber 26, is located at the connection between the first electric push rod 21 and the adjustable supersonic nozzle 22. A second slider 37, slidably connected to the second mounting chamber 38, is located at the connection between the second electric push rod 24 and the adjustable cone 23. The sliding action of the first slider 28 within the first mounting chamber 26 makes the movement of the adjustable supersonic nozzle 22 more stable, and the sliding action of the second slider 37 within the second mounting chamber makes the movement of the adjustable cone 23 more stable.

[0033] exist Figure 8 and Figure 9In the adjustable cone 23, there are a first cone 2301 and a second cone 2302 located within the second housing 102. A second cone 42 is disposed on the first cone 2301 and integrally formed with it. A third cone 32 is disposed on the second cone 2302 and integrally formed with it. The first cone 2301 and the second cone 2302 are connected by a bearing 43. A rotor 39 is sleeved on the surface of the bearing 43. A plurality of blades 44 are evenly distributed circumferentially on the circumferential side of the rotor 39. The rotation of the blades will cause the blades 44 to rotate, thereby mixing the ejected gas and the main ejected gas ejected from the adjustable supersonic nozzle 22, which improves the mixing efficiency. A first flange 5 is installed at the end of the first housing 101 opposite to the second housing 102. A second flange 6 is fitted on the surface of the end of the first housing 101 facing the second housing 102, located between the first intake pipe 2 and the second intake pipe 3. A third flange 7 is installed at the end of the second housing 102 opposite to the first housing 101. A fourth flange 8 is installed on the first intake pipe 2, the second intake pipe 3 and the exhaust pipe 4.

[0034] exist Figure 1 In the first housing 101, a first air inlet pipe 2 connected to the suction chamber 27 and a second air inlet pipe 3 connected to the first mounting chamber 26 are provided. An air inlet 29 is provided on the adjustable supersonic nozzle 22 corresponding to the second air inlet pipe 3. A low-pressure air inlet pipe 9 is connected to the first air inlet pipe 2, and a high-pressure air inlet pipe 3 is connected to the second air inlet pipe 3. A first pressure gauge 10 and a first flow meter 11 are sequentially provided on the low-pressure air inlet pipe 9. The pressure and flow rate of the ejected gas in the low-pressure air inlet pipe 9 can be detected by the first pressure gauge 10 and the first flow meter 11. A first control valve 12 for controlling the opening and closing of the low-pressure air inlet pipe 9 is also installed on the low-pressure air inlet pipe 9. The gas pipeline includes a first high-pressure gas inlet branch 13 and a second high-pressure gas inlet branch 14 that are interconnected. The first high-pressure gas inlet branch 13 is equipped with a second pressure gauge 15 and a second flow meter 16 in sequence. The pressure and flow rate of the main ejector gas in the first high-pressure gas inlet branch 13 can be detected by the second pressure gauge 15 and the second flow meter 16. The first high-pressure gas inlet branch 13 is equipped with a second control valve 17 for controlling the opening and closing of the first high-pressure gas inlet branch 13. The second high-pressure gas inlet branch 14 is equipped with a first pressure regulating valve 18 and a second pressure regulating valve 19 in sequence. The second housing 102 is also equipped with an outlet pipe 4 that is connected to the outlet chamber 36 and the second high-pressure gas inlet branch 14.

[0035] The first pressure gauge 10, the first flow meter 11, the second pressure gauge 15, and the second flow meter 16 are all connected to the calculator. The calculator, the first control valve 12, the second control valve 17, the first pressure regulating valve 18, and the second pressure regulating valve 19 are all connected to the controller. When the ejector is used, the measurement information from the first pressure gauge 10, the first flow meter 11, the second pressure gauge 15, and the second flow meter 16 is sent to the calculator. The measured information includes the pressure and flow rate of the ejected gas (low-pressure natural gas) in the low-pressure intake pipe 9 and the pressure and flow rate of the main ejected gas (mainstream natural gas) in the first high-pressure intake branch 13. The calculator outputs control commands to the controller based on the measurement information. The controller controls the opening of the first control valve 12 and the second control valve 17 to control the flow rates of the ejected gas and the main ejected gas. The controller also adjusts the opening of the first pressure regulating valve 18 and the second pressure regulating valve 19 to match the pressure in the second high-pressure intake branch 14 with the pressure of the ejector outlet gas. For details, please refer to [link to relevant documentation]. Figure 11 .

[0036] Furthermore, when using the ejector, the adjustable supersonic nozzle 22 and the adjustable cone 23 are positioned by the first electric push rod 21 and the second electric push rod 24, respectively. When the mass flow rate of the ejected gas decreases, the two are adjusted synchronously and proportionally to move in opposite directions, while simultaneously controlling the proportional reduction of the area of ​​the throat 31, outlet 33, mixing chamber inlet 34, and mixing chamber outlet 41 (straight section of mixing chamber 40) of the adjustable supersonic nozzle 22. When the mass flow rate of the ejected gas increases, the two are adjusted synchronously and proportionally to move in opposite directions, while simultaneously controlling the proportional increase of the area of ​​the four sections. The area is adjusted according to the different mass flow rates of the ejector gas to ensure successful operation of the ejector while maintaining optimal ejector performance. The ejector gas (low-pressure natural gas) is introduced into the first intake pipe 2 through the low-pressure intake pipe 9 and enters the suction chamber 27 through the first intake pipe 2. At the same time, the main ejector gas (mainstream natural gas) is introduced into the second intake pipe 3 through the second high-pressure intake branch 14 and the first high-pressure intake branch 13. The main ejector gas enters the adjustable supersonic nozzle 22 through the second intake pipe 3 and the intake port 29 on the adjustable supersonic nozzle 22.

[0037] This invention utilizes the adjustable supersonic nozzle 22 and adjustable cone 23, driven by an electric push rod, to move relative to or opposite to each other. This allows for changes in the area of ​​the throat 31, outlet 33, mixing chamber inlet 34, and mixing chamber outlet 41 of the adjustable supersonic nozzle 22. By adjusting the positions of the adjustable supersonic nozzle 22 and adjustable cone 23 in real time, key areas can be adjusted, maintaining the original pressure recovery capability while maintaining a high ejector coefficient. This self-adaptive ejector coefficient solves the problem of low ejector performance and efficiency under non-design conditions, thus ensuring maximum recovery of vented natural gas. This invention can be directly applied to natural gas long-distance pipeline compressor stations, has a small footprint, is simple to operate, and avoids the many drawbacks of additional rotating components such as compressors.

[0038] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. All equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this invention should still be covered by the claims of this invention.

Claims

1. A pressure exchange ejector, comprising an ejector housing (1), characterized in that: The ejector housing (1) is provided with an adjustable supersonic nozzle (22) driven by a first electric push rod (21) and an adjustable cone (23) driven by a second electric push rod (24). The end of the adjustable cone (23) opposite to the second electric push rod (24) passes through the adjustable supersonic nozzle (22) and is slidably connected to the adjustable supersonic nozzle (22). The ejector housing (1) is also provided with a mixing chamber inlet (34) and a mixing chamber outlet (41). The adjustable supersonic nozzle (22) is provided with a first conical part (30) corresponding to the mixing chamber inlet (34). The adjustable cone (23) is provided with a second conical part (42) corresponding to the mixing chamber outlet (41). The adjustable cone (23) is also provided with a third conical part (32) corresponding to the throat (31) and the air outlet (33) of the adjustable supersonic nozzle (22).

2. The pressure exchange ejector according to claim 1, characterized in that: The ejector housing (1) includes a first housing (101) and a second housing (102) integrally formed with the first housing (101). The first housing (101) is provided with a first mounting chamber (26) and an intake chamber (27) in sequence. The second housing (102) is provided with a mixing chamber (40), a diffuser chamber (35), an exhaust chamber (36), and a second mounting chamber (38) in sequence. The connection between the first housing (101) and the second housing (102) is the mixing chamber inlet (34). The first electric push rod (21) is located in the first mounting chamber (26) and is installed in the first housing (101) through a first adjusting block (20). The second electric push rod (24) is located in the second mounting chamber (38) and is installed in the second housing (102) through a second adjusting block (25).

3. The pressure exchange ejector according to claim 2, characterized in that: The first electric push rod (21) is provided with a first slider (28) that is slidably connected to the first mounting chamber (26) at the connection between the first electric push rod (21) and the adjustable supersonic nozzle (22), and the second electric push rod (24) is provided with a second slider (37) that is slidably connected to the second mounting chamber at the connection between the second electric push rod (24) and the adjustable cone (23).

4. A pressure exchange ejector according to claim 1, characterized in that: The adjustable cone (23) includes a first cone (2301) located in the second housing (102) and a second cone (2302) located in the first housing (101). The second cone (42) is disposed on the first cone (2301) and integrally formed with the first cone (2301). The third cone (32) is disposed on the second cone (2302) and integrally formed with the second cone (2302). The first cone (2301) and the second cone (2302) are connected by a bearing (43). A rotor (39) is sleeved on the surface of the bearing (43). The rotor (39) has a plurality of blades (44) evenly distributed along the circumferential direction on its circumferential side.

5. A pressure exchange ejector according to claim 2, characterized in that: The first housing (101) is provided with a first air inlet pipe (2) connected to the suction chamber (27) and a second air inlet pipe (3) connected to the first installation chamber (26). The adjustable supersonic nozzle (22) is provided with an air inlet (29) corresponding to the second air inlet pipe (3). A low-pressure air inlet pipe (9) is connected to the first air inlet pipe (2), and a high-pressure air inlet pipe is connected to the second air inlet pipe (3).

6. A pressure exchange ejector according to claim 5, characterized in that: The low-pressure intake pipe (9) is provided with a first pressure gauge (10) and a first flow meter (11) in sequence. The low-pressure intake pipe (9) is also provided with a first control valve (12) for controlling the opening and closing of the low-pressure intake pipe (9).

7. A pressure exchange ejector according to claim 5, characterized in that: The high-pressure intake pipeline includes a first high-pressure intake branch (13) and a second high-pressure intake branch (14) connected to each other. The first high-pressure intake branch (13) is provided with a second pressure gauge (15) and a second flow meter (16) in sequence. The first high-pressure intake branch (13) is provided with a second control valve (17) for controlling the opening and closing of the first high-pressure intake branch (13). The second high-pressure intake branch (14) is provided with a first pressure regulating valve (18) and a second pressure regulating valve (19) in sequence. The second housing (102) is also provided with an exhaust pipe (4) that is connected to the exhaust chamber (36) and the second high-pressure intake branch (14).

8. A pressure exchange ejector according to claim 5, characterized in that: A first flange (5) is installed on the end of the first housing (101) opposite to the second housing (102). A second flange (6) is fitted on the surface of the end of the first housing (101) facing the second housing (102) between the first air inlet pipe (2) and the second air inlet pipe (3). A third flange (7) is installed on the end of the second housing (102) opposite to the first housing (101). A fourth flange (8) is installed on the first air inlet pipe (2), the second air inlet pipe (3) and the air outlet pipe (4).

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