A mixed-flow pump inlet flow regulating mechanism

Abstract

This utility model discloses an inlet flow regulating mechanism for a mixed-flow pump, including an inlet flow regulating pipe, a truncated conical tangential blade regulating device, and an annular sealing device. The annular sealing device is located outside the inlet flow regulating pipe, forming a blade mounting section between the inlet flow regulating pipe and the annular sealing device. Each set of truncated conical tangential blade regulating devices includes regulating blades, regulating transmission rods, and stepper motors. The regulating blades are composed of conical flow regulating blades and ball-belt supported mating blades. The conical flow regulating blades are located inside the inlet flow regulating pipe, and the heads of all conical flow regulating blades face the pump inlet side, forming a conical structure facing the pump inlet. One end of the ball-belt supported mating blade passes through the inlet flow regulating pipe and is smoothly connected to the tail of the conical flow regulating blade. The other end of the ball-belt supported mating blade is located inside the blade mounting section and is connected to the stepper motor through the regulating transmission rod.

Description

Technical Field

[0001] This utility model relates to the field of internal flow technology in fluid machinery, specifically to a mixed-flow pump inlet flow regulating mechanism. Background Technology

[0002] A mixed-flow pump is a fluid machine that combines the characteristics of a centrifugal pump and an axial-flow pump. It is widely used in high-flow, medium-head applications such as water diversion projects, municipal drainage, and agricultural irrigation. During operation, the stability of the flow rate in the inlet pipe has a significant impact on the hydraulic performance and operational safety of the mixed-flow pump. Due to factors such as unstable inflow rates in the actual operating pipeline and untimely system adjustments, the inlet flow rate of a mixed-flow pump often fluctuates. When the inlet flow rate is insufficient, the mixed-flow pump is prone to stalling, leading to flow instability; conversely, when the inlet flow rate is excessive, cavitation is exacerbated, damaging the pump body and shortening its lifespan. Furthermore, frequent flow fluctuations cause the mixed-flow pump to deviate from its design operating point, reducing its operating efficiency and increasing system energy consumption. Therefore, real-time and stable adjustment of the inlet flow rate of the mixed-flow pump is crucial to ensuring its stable and efficient operation.

[0003] In existing flow control devices, a typical technology employs a dual-valve structure. The upper valve plate precisely controls the flow rate, while the lower valve plate opens rapidly when approaching the surge point. However, this design is primarily suitable for gas flow environments such as fans. The valve structure is mechanically complex, and the adjustment response speed is still limited by the mechanical transmission mechanism, making it unsuitable for the efficient and rapid adjustment needs of liquid flow, especially in the inlet pipes of mixed-flow pumps. Another typical technology is the telescopic bellows-type throttle valve. This type of technology achieves flow regulation through fully telescopic bellows on both sides. Its structure is relatively complex, and the bellows-type sealing structure requires high-quality sealing materials, which are prone to wear and aging over long-term operation, leading to higher maintenance costs.

[0004] Current flow regulation technologies for mixed-flow pump inlet pipelines mainly rely on traditional butterfly valves, gate valves, and ball valves, which adjust the opening degree through mechanical transmission. While these devices can achieve certain regulation functions, they generally suffer from significant lag in regulation response, complex mechanical structures, high local resistance, and difficult maintenance, failing to meet the practical needs of rapid adaptive and high-precision flow regulation for mixed-flow pump inlet pipelines.

[0005] Therefore, it is necessary to design a flow adaptive regulating device with optimized structure, sensitive adjustment, and easy maintenance, which can adjust the blade opening in real time according to the flow rate in the inlet pipe of the mixed flow pump to keep the inlet flow rate stable and ensure that the mixed flow pump can operate efficiently and safely within a large flow fluctuation range. Utility Model Content

[0006] To address the shortcomings of existing technologies, this application proposes a mixed-flow pump inlet flow regulating mechanism that adjusts the blade opening in real time according to the flow rate in the mixed-flow pump inlet pipe, thereby achieving rapid and stable control of the inlet flow rate and ensuring that the mixed-flow pump can operate efficiently and safely within a large flow fluctuation range.

[0007] The technical solution adopted in this utility model is as follows:

[0008] A mixed-flow pump inlet flow regulating mechanism includes: an inlet flow regulating pipe, a truncated cone tangential blade regulating device, and an annular sealing device;

[0009] The inlet flow regulating pipe is located between the pump inlet and the water delivery pipeline;

[0010] The annular sealing device is located outside the inlet flow regulating pipe, and the cavity between the inlet flow regulating pipe and the annular sealing device is the blade mounting section.

[0011] The truncated cone tangential blade adjustment device is arranged in several groups around the circumference. Each group of truncated cone tangential blade adjustment devices includes an adjustment blade, an adjustment transmission rod, and a stepper motor.

[0012] The regulating blade consists of a conical flow regulating blade and a ball-belt support blade. The conical flow regulating blade is located inside the inlet flow regulating pipe, and the heads of all the conical flow regulating blades face the pump inlet side, forming a conical structure facing the pump inlet.

[0013] One end of the ball belt support blade passes through the inlet flow regulating pipe and is smoothly connected to the tail of the conical flow regulating blade. The other end of the ball belt support blade is located in the blade mounting section and is connected to the stepper motor through the adjusting transmission rod.

[0014] Furthermore, several rectangular through holes are arrayed along the circumferential direction on the inlet flow regulating pipe within the blade installation section. One end of the ball belt supporting the blade passes through the rectangular through holes and smoothly connects to the tail of the conical flow regulating blade.

[0015] Furthermore, the rectangular through hole and the corresponding ball belt support blade maintain a certain clearance fit, the periphery of the through hole is welded to the outer wall with a guide groove, the inner wall of the groove is provided with a lubricating layer, and a rectangular sealing strip is added on the side near the outside of the tube.

[0016] Furthermore, the adjusting transmission rod and the stepper motor are both located on the outer wall of the inlet flow regulating pipe within the blade mounting section, and a sealed outer shell is provided outside the adjusting transmission rod and the stepper motor.

[0017] Furthermore, the aforementioned truncated cone tangential blade adjustment device is equipped with a wireless communication unit, which receives control commands, and the stepper motor drives the adjustment transmission rod according to the control commands.

[0018] Furthermore, the regulating blade is integrally formed from a conical flow regulating blade and a ball belt guide support blade.

[0019] Furthermore, the spherical guide support blade is a long strip cut from a spherical surface, with its center coinciding with the pipeline axis; the radius R of the spherical surface... s ≈2.5r0, where r0 is the inner diameter of the pipe.

[0020] Furthermore, flanges are provided at both ends of the inlet flow regulating pipe, which are used to connect to the inlet of the mixed flow pump and the water delivery pipeline, respectively.

[0021] The beneficial effects of this utility model are:

[0022] The present invention discloses a mixed-flow pump inlet flow regulating mechanism that wirelessly controls the opening of the conical flow regulating blades based on the flow rate in the mixed-flow pump inlet pipe, significantly reducing local head loss and improving the efficiency of the flow regulating device; compared with traditional throttle valves, it reduces the unbalanced force on the blades and improves operational stability; adaptive closed-loop feedback real-time regulation improves the steady-state error of the flow rate, ensuring that the mixed-flow pump can operate efficiently and safely within a large flow fluctuation range. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the flow regulating mechanism of this utility model;

[0024] Figure 2 This utility model flow regulating mechanism is along Figure 1 A three-dimensional sectional view after the GG surface is cut;

[0025] Figure 3 This is a schematic diagram of the main structure of the flow regulating mechanism of this utility model;

[0026] Figure 4 This utility model flow regulating mechanism is along Figure 3 A schematic diagram of the end face section after cutting the KK surface;

[0027] Figure 5 This is a partially enlarged cross-sectional schematic diagram of the truncated cone tangential blade adjustment mechanism in the flow regulation mechanism of this utility model;

[0028] Figure 6 This is a longitudinal sectional view of the assembly of the flow regulating mechanism of this utility model.

[0029] In the diagram, 1. Inlet flow regulating pipe, 2. Annular sealing device, 3. Regulating blade, 4. Regulating transmission rod, 5. Stepper motor, 6. Wireless communication unit, 7. Sealing shell, 8. Sealing device base, 9. Sealing cover plate, 10. Countersunk hole, 11. Sealing ring, 12. Rectangular through hole, 13. Blade mounting section, 14. Flange, 15. Conical flow regulating blade, 16. Ball belt support fitting blade, 17. Guide groove. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this utility model.

[0031] like Figure 1 As shown, the mixed-flow pump inlet flow regulating mechanism designed in this utility model includes an inlet flow regulating pipe 1, a truncated cone tangential blade regulating device, and an annular sealing device 2.

[0032] like Figure 2 As shown, flanges 14 are provided at both ends of the inlet flow regulating pipe 1, which are used to connect to the inlet end of the mixed flow pump and the water supply pipeline, respectively.

[0033] An annular sealing device 2 is provided on the outside of the inlet flow regulating pipe 1, and the annular sealing device 2 is arranged coaxially with the inlet flow regulating pipe 1. The annular sealing device 2 is a semi-closed structure, and a countersunk hole 10 is opened at the open end of the annular sealing device 2. Fasteners are used to cooperate with the countersunk hole 10 to securely connect the sealing cover plate 9 to the open end of the annular sealing device 2. A sealing ring 11 is provided at the connection between the sealing cover plate 9 and the inlet flow regulating pipe 1. The closed end of the annular sealing device 2 is fixedly connected to the outside of the inlet flow regulating pipe by welding. Thus, a cavity is formed between the inlet flow regulating pipe 1 and the annular sealing device 2, and this cavity is the blade mounting section 13.

[0034] like Figure 3 , 4 As shown in Figure 5, several sets of truncated cone tangential blade adjustment devices are installed within the blade mounting section 13. Each set of truncated cone tangential blade adjustment devices includes an adjustment blade 3, an adjustment transmission rod 4, and a stepper motor 5. The specific connection relationships are as follows:

[0035] Several rectangular through holes 12 are arrayed along the circumferential direction on the inlet flow regulating pipe 1 inside the blade mounting section 13, and the rectangular through holes 12 correspond one-to-one with the regulating blades 3.

[0036] The regulating blade 3 is composed of two opposite arc-shaped segments, namely a conical flow regulating blade 15 and a ball-belt support fitting blade 16; wherein, the conical flow regulating blade 15 is located inside the inlet flow regulating pipe 1, and the heads of all the conical flow regulating blades 15 protrude towards the pump inlet side, thus forming a conical structure facing the pump inlet.

[0037] The ball belt support mating blade 16 and the conical flow regulating blade 15 have opposite bending directions. One end of the ball belt support mating blade 16 passes through the rectangular through hole 12 and is smoothly connected to the tail of the conical flow regulating blade 15. The other end of the ball belt support mating blade 16 is located in the blade mounting section 13 and is connected to the stepper motor 5 through the adjusting transmission rod 4.

[0038] The adjusting transmission rod 4 and the stepper motor 5 are both located on the outer wall of the inlet flow regulating pipe 1 within the blade mounting section 13. The adjusting transmission rod 4 and the stepper motor 5 are externally equipped with a sealed housing 7.

[0039] During flow regulation, the connection point between the regulating transmission rod 4 and the stepper motor 5 serves as the fulcrum. The stepper motor 5 drives the regulating transmission rod 4 to rotate towards or away from the inlet flow regulation pipe 1. When the regulating transmission rod 4 rotates towards the inlet flow regulation pipe 1, it causes the regulating blades 3 to move inward tangentially, causing all the conical flow regulation blades 15 of the regulating blades 3 to close and narrow the flow channel. Conversely, when the regulating transmission rod 4 rotates away from the inlet flow regulation pipe 1, it causes the regulating blades 3 to move outward tangentially, causing all the conical flow regulation blades 15 of the regulating blades 3 to separate and widen the flow channel.

[0040] In this embodiment, each rectangular through hole 12 maintains a certain clearance fit with the corresponding ball belt support blade 16. The periphery of the through hole is welded to the outer wall with a guide groove 17. A lubrication layer is provided on the inner wall of the groove, and a rectangular sealing strip is added on the side near the outside of the tube to ensure smooth tangential movement of the blade and good sealing conditions.

[0041] In this embodiment, as Figure 3 and Figure 4 As shown, the truncated cone tangential blade adjustment device is also equipped with a wireless communication unit 6. The wireless communication unit 6 receives control commands, and the stepper motor 5 drives the adjustment transmission rod 4 according to the control commands to realize wireless control of the truncated cone tangential blade adjustment device.

[0042] In this embodiment, the regulating blade 3 is integrally formed from a conical flow regulating blade 15 and a ball belt guide support blade 16. The root of the blade transitions smoothly with the ball belt guide support blade.

[0043] In this embodiment, the spherical guide support blade 16 is a long strip cut from a spherical surface, with its center coinciding with the pipeline axis; the radius R of the spherical surface... s ≈2.5r0 (r0 is the inner diameter of the pipe). The ball belt guide support blades are connected to the adjusting transmission rod 4 by screws. The number of blades N is selected according to the flow rate and adjustment accuracy; in this embodiment, N = 4 blades are selected.

[0044] In this embodiment, as Figure 5 As shown, the stepper motor 5 and the wireless communication unit 6 are fixed to the outside of the pipe and located inside the sealed housing to form a dry cavity. The stepper motor 5 is a waterproof motor, and the wireless communication unit 6 is fixed to the rear end of the motor to establish a data link with the computing unit to complete precise control.

[0045] Based on the above-described device, the adjustment process of this device is as follows:

[0046] Step 1: Zeroing the position. By closing the blades to the maximum extent, the zero point of the flow adaptive regulating device is ensured to be accurate.

[0047] Step 2: Install an electromagnetic or ultrasonic flow meter 10m downstream of the inlet flow regulating pipe 1. The flow meter collects the instantaneous flow rate Q with a sampling period of 50ms. After being converted into a digital signal by an AD converter, it is transmitted to the computing unit.

[0048] Step 3: The calculation unit obtains the flow deviation by comparing the instantaneous flow rate Q with the preset target flow rate, and transmits the real-time position information of the blades in reverse from the wireless communication unit 6.

[0049] Step 4: The blade displacement command is sent to the stepper motor drive module via a wireless communication unit. After receiving the command, the drive module generates a pulse sequence to drive the stepper motor to rotate.

[0050] Step 5: Stepper motor 5 drives each adjusting blade 3 to generate synchronous tangential displacement via adjusting transmission rod 4. After the blades are adjusted and stabilized for 0.2 seconds, the real-time flow rate is measured again. If the flow rate deviation is greater than the predetermined value, the above steps are repeated; otherwise, the current blade position is maintained.

[0051] More preferably, since it is impossible to guarantee that the instantaneous flow rate Q is exactly the same as the preset target flow rate in actual work, the present invention sets a maximum flow rate fluctuation value. When the flow rate deviation is within the range of the maximum flow rate fluctuation value, it is considered that the instantaneous flow rate Q meets the preset target flow rate requirement.

[0052] More preferably, if there is a linear relationship between the momentum of the stepper motor 5, the adjusting transmission rod 4, the adjusting blade 3, the opening degree of the flow regulating device, and the flow rate, then the mathematical formula between momentum and opening degree can be directly derived. In the calculation unit, the control command for the momentum of the stepper motor 5 can be obtained directly based on the flow rate, and the adjustment of the adjusting transmission rod 4 and the adjusting blade 3 can be executed based on the command to meet the target flow rate requirement.

[0053] More preferably, if there is no linear relationship between the motion of the stepper motor 5, the adjusting transmission rod 4, the adjusting blade 3, the opening and closing degree of the flow regulating device, and the flow rate, then an adaptive PID algorithm can be called. An adaptive PID algorithm is built into the calculation unit, and the flow rate deviation and the real-time position of the blade are used as inputs to the adaptive PID algorithm. The PID algorithm obtains the blade displacement command by fitting according to fuzzy rules.

[0054] The above embodiments are only used to illustrate the design concept and features of this utility model, and their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. The protection scope of this utility model is not limited to the above embodiments. Therefore, all equivalent changes or modifications made based on the principles and design ideas disclosed in this utility model are within the protection scope of this utility model.

Claims

1. A mixed-flow pump inlet flow regulating mechanism, characterized in that, include: Inlet flow regulating pipe (1), truncated cone tangential blade regulating device and annular sealing device (2); The inlet flow regulating pipe (1) is located between the pump inlet and the water delivery pipeline; The annular sealing device (2) is located outside the inlet flow regulating pipe (1), and the cavity between the inlet flow regulating pipe (1) and the annular sealing device (2) is the blade mounting section (13). The truncated cone tangential blade adjustment device is arranged in several groups around the circumference. Each group of truncated cone tangential blade adjustment devices includes an adjustment blade (3), an adjustment transmission rod (4), and a stepper motor (5). The regulating blade (3) is composed of a conical flow regulating blade (15) and a ball belt support fitting blade (16). The conical flow regulating blade (15) is located inside the inlet flow regulating pipe (1). The heads of all the conical flow regulating blades (15) face the pump inlet side, forming a conical structure facing the pump inlet. One end of the ball belt support mating blade (16) passes through the inlet flow regulating pipe (1) and is smoothly connected to the tail of the conical flow regulating blade (15). The other end of the ball belt support mating blade (16) is located in the blade mounting section (13) and is connected to the stepper motor (5) through the adjusting transmission rod (4).

2. The mixed-flow pump inlet flow regulating mechanism according to claim 1, characterized in that, Several rectangular through holes (12) are arrayed along the circumferential direction on the inlet flow regulating pipe (1) in the blade installation section (13). One end of the ball belt support and mating blade (16) passes through the rectangular through holes (12) and is smoothly connected to the tail of the conical flow regulating blade (15).

3. The mixed-flow pump inlet flow regulating mechanism according to claim 2, characterized in that, The rectangular through hole (12) and the corresponding ball belt support blade (16) maintain a certain clearance fit. The periphery of the through hole is welded to the outer wall with a guide groove (17). A lubrication layer is provided on the inner wall of the groove, and a rectangular sealing strip is added on the side near the outside of the tube.

4. The mixed-flow pump inlet flow regulating mechanism according to claim 1, characterized in that, The regulating transmission rod (4) and the stepper motor (5) are both located on the outer wall of the inlet flow regulating pipe (1) inside the blade mounting section (13), and a sealed outer shell (7) is provided outside the regulating transmission rod (4) and the stepper motor (5).

5. The mixed-flow pump inlet flow regulating mechanism according to claim 1, characterized in that, The truncated cone tangential blade adjustment device is equipped with a wireless communication unit (6). The wireless communication unit (6) receives control commands, and the stepper motor (5) drives the adjustment transmission rod (4) according to the control commands.

6. The mixed-flow pump inlet flow regulating mechanism according to claim 1, characterized in that, The regulating blade (3) is integrally formed from the conical flow regulating blade (15) and the ball belt guide support blade.

7. The mixed-flow pump inlet flow regulating mechanism according to claim 6, characterized in that, The spherical guide support blade (16) is a long strip cut from a spherical surface, with its center coinciding with the pipeline axis; the radius of the spherical surface R s ≈2.5r0, where r0 is the inner diameter of the pipe.

8. The mixed-flow pump inlet flow regulating mechanism according to claim 1, characterized in that, The inlet flow regulating pipe (1) is equipped with flanges (14) at both ends, which are used to connect to the inlet end of the mixed flow pump and the water supply pipeline, respectively.

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