A full-operating ejector

Abstract

The present application discloses a full-operating-condition ejector, which relates to the technical field of ejectors, and includes a plurality of sub-ejectors arranged in parallel; the sub-ejector includes a nozzle front end tube, a nozzle inlet is provided on the nozzle front end tube, the nozzle inlet on the nozzle front end tube is connected to a high-pressure inlet, a low-pressure chamber is provided at one end of the nozzle front end tube, and a low-pressure inlet is provided on the low-pressure chamber; the nozzle is located in the low-pressure chamber, a mixing chamber connected to the low-pressure chamber is provided at one end of the nozzle, and a medium-pressure outlet is provided at one end of the mixing chamber; the regulating core is located in the mixing chamber, and the end of the regulating core close to the nozzle is conical; the other end of the nozzle front end tube is closed, and an actuator is provided at this end, and the actuator drives the regulating core to move axially through a valve stem, and the valve stem is connected to the regulating core. In this way, the problem of the decrease of the ejection ratio under the variable operating conditions of the traditional adjustable ejector is solved, and the area ratio is converted into a controllable favorable factor to achieve the regulation of the flow load under the full operating conditions.

Description

Technical Field

[0001] The present application relates to the technical field of ejectors, and in particular to a full-operating ejector. Background Art

[0002] Traditional adjustable ejectors such as Figure 1 As shown, only the area of ​​the nozzle can be changed during the adjustment process. In other words, only the high-pressure steam intake can be adjusted when the pressure and temperature conditions remain unchanged.

[0003] The adjustment core moves and the nozzle area changes, but the purpose is only to change the flow output. The best injection ratio cannot be calculated through online calculation. Only by changing the nozzle area, the area ratio of the nozzle outlet and the mixing chamber changes, which leads to a change in the internal area ratio, making the area ratio uncontrollable and deviating from the optimal value, which worsens the injection effect.

[0004] Usually, in the design of ejectors, the best area ratio (mixing chamber cross-sectional area / nozzle cross-sectional area) is selected, that is, the ejection ratio (low-pressure flow / high-pressure flow) is maximized. Once the area ratio changes, increases or decreases, the ejection ratio will decrease until there is no ejection.

[0005] The pressure and temperature of the high pressure inlet, low pressure inlet and medium pressure outlet determine the optimal area ratio and the maximum ejection ratio. If any parameter changes during operation, the ejection effect will be affected or the "no ejection" phenomenon will occur.

[0006] Traditional products can only be used under low parameter conditions because the regulating valve stem is at the high-pressure end and it is difficult to seal against high-temperature and high-pressure media.

[0007] In order to solve the above problems, the inventors have improved the existing technical solutions and proposed a "full-operating-condition ejector" solution. Utility Model Content

[0008] In order to solve the problems existing in traditional adjustable ejectors, the area ratio is converted into a controllable favorable factor. By changing the nozzle area and the area ratio of the mixing chamber and the nozzle, the area ratio is always kept in the optimal state, thereby achieving controllable adjustment of the flow load under all operating conditions. Therefore, the present application provides an ejector under all operating conditions.

[0009] The present application provides a full-operating condition ejector adopts the following technical solution.

[0010] A full-operating ejector, comprising: a plurality of sub-ejectors arranged in parallel;

[0011] The sub-ejector comprises a nozzle front end tube, a nozzle inlet is provided on the nozzle front end tube, the nozzle inlet on the nozzle front end tube is connected with a high-pressure inlet, a low-pressure chamber is provided at the front end of the nozzle front end tube, and a low-pressure inlet is provided on the low-pressure chamber; a nozzle is provided at the front end of the nozzle front end tube, the nozzle is located in the low-pressure chamber, a mixing chamber is provided at the front end of the low-pressure chamber, and a medium-pressure outlet is provided at the front end of the mixing chamber; an adjusting core is provided in the mixing chamber at the front end of the nozzle, and the adjusting core is tapered at one end close to the nozzle;

[0012] The rear end of the nozzle front end tube is closed and has an actuator at this end. The actuator drives the regulating core to move axially through the valve stem. The valve stem penetrates the nozzle front end tube and the nozzle and is connected to the regulating core.

[0013] By adopting the above technical solution, the actuator drives the adjustment core to move axially, and the nozzle area is changed by adjusting the core to be close to or away from the nozzle. The area ratio of the mixing chamber and the nozzle is changed through this adjustment method. This adjustment method does not need to change the cross-sectional area of ​​the mixing chamber, has a simpler structure, is easy to implement, has low manufacturing cost and good reliability.

[0014] Optionally, several nozzle inlets are opened along the circumferential direction of the nozzle front end tube, a high-pressure inlet pipe is coaxially arranged on the periphery of the nozzle front end tube, a high-pressure inlet is opened on the high-pressure inlet pipe, both ends of the high-pressure inlet pipe are sealed with the outer wall of the nozzle front end tube to form a high-pressure cavity, and the high-pressure cavity is connected to the nozzle inlet.

[0015] By adopting the above technical solution, the high-pressure chamber and the multiple nozzle inlets are arranged, which is conducive to improving the stability of the high-pressure medium entering the nozzle front end tube, ensuring that the high-pressure medium can be sprayed out from the nozzle in a stable and balanced manner.

[0016] Optionally, the middle diameter of the nozzle is smaller than the diameters at both ends.

[0017] Optionally, a pressure relief block is provided on the valve stem. The pressure relief block is inside the front end tube of the nozzle, located at the rear end position of the nozzle inlet, and slidingly fits with the inner wall gap of the front end tube of the nozzle.

[0018] By adopting the above technical solution and setting the pressure relief block, the leakage of the high-pressure medium is limited.

[0019] Optionally, a pressure relief chamber is formed between the pressure relief block and the rear end of the front end tube of the nozzle, and the pressure relief chamber is connected to the low-pressure inlet through the pressure relief pipe.

[0020] By adopting the above technical solution, a small amount of high-pressure medium leaks through the pressure relief block and enters the pressure relief chamber. The high-pressure medium in the pressure relief chamber can be connected to the low-pressure inlet through the pressure relief pipe to achieve pressure relief.

[0021] Optionally, the pressure relief block includes a plurality of pressure relief plates arranged at intervals, and the edge of the pressure relief plate close to one end of the pressure relief chamber is chamfered, a gap is set between the edge of the pressure relief plate and the inner wall of the front end tube of the nozzle, and a vortex groove is formed between each two adjacent pressure relief plates.

[0022] By adopting the above technical solution, multiple pressure relief plates are arranged at intervals, and the edge chamfer of the pressure relief plate near one end of the pressure relief chamber is arranged to form a multi-stage vortex groove, which can reduce the pressure of the leaked high-pressure medium step by step, play a throttling role, and after consuming kinetic energy and pressure energy in each stage of the vortex groove, it enters the next stage until it flows out of the last stage and enters the pressure relief chamber. Since the pressure in the pressure relief chamber is close to the pressure of the low-pressure inlet, the sealing problem of the valve stem can be well solved. And because the pressure of the pressure relief chamber is approximately equal to the pressure of the low-pressure inlet, that is, the nozzle outlet, the thrust on the regulating core is balanced. Therefore, there is no need to use a large thrust actuator.

[0023] Optionally, a bracket for supporting the regulating core is provided at the medium-pressure outlet.

[0024] By adopting the above technical solution, the setting of the bracket plays an effective supporting role at the front end of the adjusting core.

[0025] Optionally, the horizontal cross-sections at both ends of the bracket are conical.

[0026] By adopting the above technical solution and through the conical design, the blocking interference to the medium-pressure medium can be reduced.

[0027] Optionally, the low-pressure inlet of each sub-ejector is provided with a check valve.

[0028] By adopting the above technical solution and setting the check valve, it is possible to prevent the high-pressure or medium-pressure medium from flowing back into the pipeline where the low-pressure medium is located.

[0029] Optionally, the high-pressure inlets of several sub-ejectors are connected to the high-pressure steam inlet pipe, the low-pressure inlets of several sub-ejectors are connected to the low-pressure steam inlet pipe, and the medium-pressure outlets of several sub-ejectors are connected to the medium-pressure steam outlet pipe.

[0030] By adopting the above technical solution, several sub-ejectors are connected in parallel to form a full-operating condition ejector. The concept of a full-operating condition ejector means that the ejector can achieve efficient operation under all operating conditions, that is, according to the actual operating parameters, the maximum set opening of each ejector is continuously corrected so that it always operates under the optimal area ratio. The adjustment of the total output is achieved by changing the opening of the sub-ejector and the number of units put into use.

[0031] In summary, this application at least includes the following beneficial effects:

[0032] 1. The actuator drives the adjusting core to move axially, and the nozzle area is changed by adjusting the core close to or away from the nozzle. This adjustment method changes the area ratio of the mixing chamber to the nozzle. This adjustment method does not need to change the cross-sectional area of ​​the mixing chamber, has a simpler structure, is easy to implement, has low manufacturing cost, and has good reliability.

[0033] 2. The pressure relief block includes a plurality of pressure relief plates arranged at intervals, and the edge chamfer of the pressure relief plate near one end of the pressure relief chamber is set, and a gap is set between the edge of the pressure relief plate and the inner wall of the nozzle front end tube, and a vortex groove is formed between each adjacent pressure relief plate. Multiple pressure relief plates are arranged at intervals, and the edge chamfer of the pressure relief plate near one end of the pressure relief chamber forms a multi-stage vortex groove, which can reduce the pressure of the leaked high-pressure medium step by step, play a throttling role, and after consuming kinetic energy and pressure energy in each stage of the vortex groove, it enters the next stage until the last stage flows out and enters the pressure relief chamber. Since the pressure in the pressure relief chamber is close to the pressure of the low-pressure inlet, the sealing problem of the valve stem can be well solved. And since the pressure of the pressure relief chamber is approximately equal to the pressure of the low-pressure inlet, that is, the nozzle outlet, the thrust on the regulating core is balanced. Therefore, there is no need to use a large thrust actuator.

[0034] 3. Each sub-ejector is equipped with a check valve at its low-pressure inlet. The check valve can prevent the high-pressure or medium-pressure medium from flowing back into the pipeline where the low-pressure medium is located.

[0035] 4. The high-pressure inlets of several sub-ejectors are connected to the high-pressure steam inlet pipe, the low-pressure inlets of several sub-ejectors are connected to the low-pressure steam inlet pipe, and the medium-pressure outlets of several sub-ejectors are connected to the medium-pressure steam outlet pipe. Several sub-ejectors are connected in parallel to form a full-operating condition ejector. The optimal area ratio and total output under each operating condition can be adjusted by controlling the opening and closing state of each sub-ejector nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 It is a schematic diagram of the structure of a traditional adjustable ejector.

[0038] Figure 2 It is a schematic diagram of the sub-ejector structure.

[0039] Figure 3 It is a schematic diagram of the structure of the sub-ejector (including the operator).

[0040] Figure 4 It is a schematic diagram of the pressure relief block.

[0041] Figure 5 It is a schematic diagram of an ejector in full working condition.

[0042] Explanation of the reference numerals in the accompanying drawings: 1. nozzle inlet; 2. high-pressure inlet; 3. high-pressure chamber; 4. low-pressure chamber; 5. low-pressure inlet; 6. nozzle; 7. mixing chamber; 8. medium-pressure outlet; 9. adjusting core; 10. actuator; 11. valve stem; 12. pressure relief block; 13. pressure relief chamber; 14. pressure relief pipe; 15. pressure relief plate; 16. vortex groove; 17. bracket; 18. high-pressure steam inlet pipe; 19. low-pressure steam inlet pipe; 20. medium-pressure steam outlet pipe; 21. check valve. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0044] The following is combined with Figures 1 to 5 This application is described in further detail.

[0045] The embodiment of the present application discloses a full-operating-condition ejector.

[0046] Reference Figures 1 to 5 , a full-operating condition ejector, comprising: a plurality of sub-ejectors.

[0047] The sub-ejector includes a nozzle front end tube, on which a nozzle inlet 1 is provided, and a plurality of nozzle inlets 1 are provided along the circumferential direction of the nozzle front end tube. A high-pressure inlet pipe is coaxially fixedly provided on the outer periphery of the nozzle front end tube, and a high-pressure inlet 2 is provided on the high-pressure inlet pipe. Both ends of the high-pressure inlet pipe are sealed with the outer wall of the nozzle front end tube to form a high-pressure chamber 3, and the high-pressure chamber 3 is connected to the plurality of nozzle inlets 1. The arrangement of the high-pressure chamber 3 and the plurality of nozzle inlets 1 is conducive to improving the stability of the high-pressure medium entering the nozzle front end tube, and ensuring that the high-pressure medium can be stably and balancedly ejected from the nozzle 6.

[0048] A low-pressure chamber 4 is fixedly arranged at the front end of the nozzle front end tube, a low-pressure inlet 5 is opened on the low-pressure chamber 4, a nozzle 6 is arranged at the front end of the nozzle front end tube, the middle diameter of the nozzle 6 is smaller than the diameter at both ends, the nozzle 6 is located in the low-pressure chamber 4, the front end of the low-pressure chamber 4 is connected to a mixing chamber 7, and a medium-pressure outlet 8 is opened at the front end of the mixing chamber 7.

[0049] An adjusting core 9 is arranged in the mixing chamber 7 at the front end of the nozzle 6 , and the end of the adjusting core 9 close to the nozzle 6 is tapered.

[0050] The rear end of the nozzle front end tube is closed, and an actuator 10 is provided at this end. The valve stem 11 passes through the nozzle front end tube and the nozzle 6. The front end of the valve stem 11 is fixedly connected to the adjusting core 9. The actuator 10 drives the adjusting core 9 to move axially through the valve stem 11.

[0051] The actuator 10 drives the adjustment core 9 to move axially, and the area of ​​the nozzle 6 is changed by adjusting the core 9 to be close to or away from the nozzle 6. This adjustment method changes the area ratio of the mixing chamber 7 to the nozzle 6. This adjustment method does not need to change the cross-sectional area of ​​the mixing chamber, has a simpler structure, is easy to implement, has a low manufacturing cost, and has good reliability.

[0052] A pressure relief block 12 is fixedly provided on the valve stem 11. The pressure relief block 12 is a multi-stage vortex groove. The pressure relief block 12 is in the front end tube of the nozzle, located at the rear end of the nozzle inlet 1, and slidingly fits with the inner wall gap of the front end tube of the nozzle. The leakage of the high-pressure medium is limited by the setting of the pressure relief block 12.

[0053] A pressure relief chamber 13 is formed between the pressure relief block 12 and the rear end of the front end tube of the nozzle. The pressure relief chamber 13 is connected to the low pressure inlet 5 through the pressure relief pipe 14. A small amount of high pressure medium leaks through the pressure relief block 12 and enters the pressure relief chamber 13. The high pressure medium in the pressure relief chamber 13 can be connected to the low pressure inlet 5 through the pressure relief pipe 14 to achieve pressure relief. The pressure relief block 12 includes a plurality of pressure relief plates 15 arranged at intervals, and the edge of the pressure relief plate 15 near one end of the pressure relief chamber 13 is chamfered, and a gap is set between the edge of the pressure relief plate 15 and the inner wall of the front end tube of the nozzle. A vortex groove 16 is formed between each adjacent two pressure relief plates 15. The plurality of pressure relief plates 15 arranged at intervals and the edge of the pressure relief plate 15 near one end of the pressure relief chamber 13 are chamfered, forming a multi-stage vortex groove, which can reduce the pressure of the leaked high pressure medium step by step, and play a throttling role. After consuming kinetic energy and pressure energy in each stage of the vortex groove 16, it enters the next stage until it flows out of the last stage and enters the pressure relief chamber 13. Since the pressure in the pressure relief chamber 13 is close to the pressure of the low pressure inlet 5, the sealing problem of the valve stem 11 can be well solved. And since the pressure in the pressure relief chamber 13 is approximately equal to the pressure of the low pressure inlet 5, i.e., the outlet of the nozzle 6, the thrust on the regulating core 9 is balanced, so there is no need to select a high thrust actuator 10.

[0054] A bracket 17 for supporting the regulating core 9 is provided at the medium pressure outlet 8. The arrangement of the bracket 17 plays an effective supporting role at the front end of the regulating core 9. The horizontal cross-sections at both ends of the bracket 17 are both conical. The number of brackets 17 is generally two or four symmetrically distributed. The conical design can reduce the blocking interference to the medium pressure medium.

[0055] For each working condition, there is an optimal area ratio, which can be calculated online in real time by the operator. By changing the stroke of the regulating core 9, the area of ​​the nozzle 6 can be changed, while the area of ​​the mixing chamber 7 remains unchanged, that is, the ratio of the two can be changed, so that adaptive adjustment can be continuously performed to keep the area ratio at the optimal value.

[0056] The full-operating condition ejector is composed of several sub-ejectors arranged in parallel, so that the optimal area ratio can be adjusted under each operating condition.

[0057] The regulation of flow load is achieved by changing the number of units put into use, that is, this full-condition adaptable ejector requires the use of multiple sub-ejectors. The high-pressure inlets 2 of several sub-ejectors are connected to the high-pressure steam inlet pipe 18, the low-pressure inlets 5 of several sub-ejectors are connected to the low-pressure steam inlet pipe 19, and the medium-pressure outlets 8 of several sub-ejectors are connected to the medium-pressure steam outlet pipe 20. Several sub-ejectors are connected in parallel to form a full-condition ejector. By controlling the opening and closing states of several sub-ejector nozzles 6, the optimal area ratio under each working condition is adjusted. The concept of a full-condition ejector means that the ejector can achieve efficient operation under all working conditions, that is, according to the actual operating parameters, the maximum set opening of each ejector is continuously corrected so that it always operates under the optimal area ratio. The regulation of the total output is achieved by changing the opening of the sub-ejectors and the number of units put into use.

[0058] A check valve 21 is provided at the low-pressure inlet 5 of each sub-ejector. The check valve 21 can prevent the high-pressure or medium-pressure medium from flowing back to the pipeline where the low-pressure medium is located.

[0059] By changing the opening of the nozzle 6 and adjusting the area ratio, the ideal area ratio is calculated based on the online parameters, that is, an ideal nozzle opening is determined, and this ideal opening is set as the maximum opening of each sub-ejector in a timely manner online. The total output is adjusted by jointly adjusting the opening of each sub-ejector and the number of units put into use.

[0060] In order to accurately adjust the flow rate, one needs to be in a "half-open" state for tracking and adjustment, and the others are either fully open, i.e., in the best state, or fully closed. The operator continuously gives the best opening as the maximum opening, and sends a signal to each actuator 10 to make it continuously adjusted. When the half-open state reaches the maximum opening, the next one is automatically switched on. With the fluctuation of the parameters, the best opening, i.e., the maximum opening, of each one changes continuously to adapt to the parameters.

[0061] In the description of the present utility model, it should be understood that the terms "front end", "one end", "middle", "rear end", "two ends", "ends" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In the description of the present utility model, unless otherwise specified and limited, it should be noted that the term "connection" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the internal connection of two elements, it can be a direct connection, or it can be an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0062] The above are only preferred embodiments of the utility model and are not intended to limit the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A full-operating ejector, characterized in that: include: A plurality of sub-ejectors arranged in parallel; The sub-ejector comprises a nozzle front end tube, a nozzle inlet is provided on the nozzle front end tube, the nozzle inlet on the nozzle front end tube is connected with a high-pressure inlet, a low-pressure cavity is provided at the front end of the nozzle front end tube, and a low-pressure inlet is provided on the low-pressure cavity; A nozzle is arranged at the front end of the nozzle front end tube, and the nozzle is located in the low-pressure chamber. The front end of the low-pressure chamber is connected to a mixing chamber, and a medium-pressure outlet is opened at the front end of the mixing chamber. An adjusting core is arranged in the mixing chamber at the front end of the nozzle, and the end of the adjusting core close to the nozzle is conical. The rear end of the nozzle front end tube is closed and has an actuator at this end. The actuator drives the regulating core to move axially through the valve stem. The valve stem penetrates the nozzle front end tube and the nozzle and is connected to the regulating core.

2. A full-operation ejector according to claim 1, characterized in that: The nozzle inlet is provided with a plurality of them along the circumferential direction of the nozzle front end tube, a high-pressure inlet pipe is coaxially arranged on the periphery of the nozzle front end tube, a high-pressure inlet is provided on the high-pressure inlet pipe, both ends of the high-pressure inlet pipe are sealed with the outer wall of the nozzle front end tube to form a high-pressure cavity, and the high-pressure cavity is connected with the nozzle inlet.

3. The full-operation ejector according to claim 1, characterized in that: The middle diameter of the nozzle is smaller than the diameters at both ends.

4. The full-operation ejector according to claim 1, characterized in that: The valve stem is provided with a pressure relief block, which is located in the front end tube of the nozzle, at the rear end of the nozzle inlet, and is slidably matched with the inner wall gap of the front end tube of the nozzle.

5. The full-operation ejector according to claim 4, characterized in that: A pressure relief chamber is formed between the pressure relief block and the rear end of the front end tube of the nozzle, and the pressure relief chamber is connected with the low-pressure inlet through the pressure relief tube.

6. The full-operation ejector according to claim 5, characterized in that: The pressure relief block includes a plurality of pressure relief plates arranged at intervals, and the edge of the pressure relief plate close to one end of the pressure relief chamber is chamfered, a gap is set between the edge of the pressure relief plate and the inner wall of the front end tube of the nozzle, and a vortex groove is formed between every two adjacent pressure relief plates.

7. The full-operation ejector according to claim 1, characterized in that: A bracket for supporting the regulating core is arranged at the medium pressure outlet.

8. The full-operation ejector according to claim 7, characterized in that: The horizontal cross sections of both ends of the bracket are tapered.

9. The full-operation ejector according to claim 1, characterized in that: The low-pressure inlet of each sub-ejector is provided with a check valve.

10. The full-operation ejector according to claim 1, characterized in that: The high-pressure inlets of several sub-ejectors are all connected to the high-pressure steam inlet pipe, the low-pressure inlets of several sub-ejectors are all connected to the low-pressure steam inlet pipe, and the medium-pressure outlets of several sub-ejectors are all connected to the medium-pressure steam outlet pipe.

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