Large-scale bulb tubular pump device having structure capable of suppressing tail vortices

Abstract

Provided in the present invention is a large-scale bulb tubular pump device having a structure capable of suppressing tail vortices, the device comprising a bulb body located in a bulb body flow chann

Description

[0001] The present invention relates to the technical field of bulb tubular pumps, and in particular, to a large bulb tubular pump device configured for suppressing tail vortex structures. BACKGROUND

[0002] Large bulb tubular pumps, as highly efficient hydraulic machinery, are widely applied in fields such as large water conservancy projects, urban water supply, and sewage treatment. In these applications, stability and high efficiency of a pump device are crucial for operation of the entire system. However, during operation of a tubular pump, complex vortex structures are often generated in its tail flow field. Especially in large and even extra-large tubular pump units, vibration and noise caused by tail vortices become more severe, which significantly impacts system stability. In addition, such vortices may further cause hydraulic losses, and affect overall efficiency of the pump, thereby imposing negative impacts on long-term operation of the device.

[0003] In existing large bulb tubular pump units, specific bulb structures are typically adopted to suppress vortices. A ratio of a length of a tail of a bulb to a maximum diameter of the bulb typically ranges from 0.5 to 1.5. However, for large or extra-large bulb tubular pump units, it is usually difficult to effectively eliminate tail vortices. Increasing the length of the tail of the bulb can, to some extent, mitigate the vortices caused by flow separation, but it may lead to an increase in both the size and weight of the bulb, which poses a great challenge to fixation and structural stability of the bulb. In addition, due to the influence of components such as a support structure of the bulb, adverse flow patterns including flow deflection and secondary flow are also relatively obvious. Therefore, designing a more efficient and simple-structured tail vortex suppression structure has become an urgent issue to be solved in the field of large bulb tubular pumps. SUMMARY

[0004] In response to the shortcomings of the prior art, the present invention provides a large bulb tubular pump device configured for suppressing tail vortex structures. By integrating a tail of a bulb with a diversion pier, not only an effective support structure is provided for the lengthened bulb, but also mechanical strength and stability of the entire device are enhanced. The reasonable design of the diversion pier ensures that no obvious local flow loss occurs when a fluid passes through this region, while improving durability of equipment. An extension line of a contour of the tail of the bulb is tangent to a thickness of the diversion pier, which can effectively reduce vortex intensity in a wake flow field, thereby improving operational efficiency of the pump device, reducing vibration and noise, and extending service life of the equipment.

[0005] The present invention achieves the above technical objectives through the following technical means.

[0006] A large bulb tubular pump device configured for suppressing tail vortex structures includes a bulb located in a bulb flow passage and a diversion pier located in an outlet flow passage. The diversion pier is located behind the bulb, and one end of the diversion pier extends to a contour of a tail of the bulb, for reducing flow losses between the diversion pier and the tail of the bulb;

[0007] an extension line of the contour of the tail of the bulb is tangent to the diversion pier to suppress generation of tail vortices;

[0008] the bulb is supported in the bulb flow passage by an upper support and a lower support, and an upper part and a lower part of one end of the diversion pier are respectively connected to the upper support and the lower support, to evenly divide each of the bulb flow passage and the outlet flow passage into two parts to suppress flow deflection, avoid adverse flow patterns in the flow field, and ensure that a fluid flows out stably and efficiently along a predetermined path;

[0009] the bulb includes a guide vane diffuser section, a cylindrical section, and a tail cone section, where the guide vane diffuser section, the cylindrical section, and the tail cone section are connected sequentially in a flow direction; a surface of the guide vane diffuser section is configured to mount guide vanes, the cylindrical section is configured to accommodate a power unit, and one end of the diversion pier extends to the tail cone section; and

[0010] a minimum distance from a tangent point between an extension line of the tail cone section and the diversion pier to the cylindrical section is h, and a diameter of a tangent point position is d2, meeting the following relations: l4=(6~9)d, d2=(0.2~0.6)d,

[0011] where d is an outer diameter of the cylindrical section, and a length of the tail cone section is 12=0.5 U.

[0012] The length of the tail cone section is l2=(3~4.5)d, which greatly extends the length of the bulb, slows down diffusion and separation of the fluid in the flow passages, and effectively suppresses the generation of the tail vortices. The bulb is truncated at a position where it is integrated with the diversion pier, which reduces both length and weight of the bulb on the premise of ensuring flow stability, and lowers manufacturing costs.

[0013] Furthermore, the upper support and the lower support are hollow structures, and the hollow structures of the upper support and the lower support are respectively in communication with an interior of the cylindrical section of the bulb for the convenience of equipment maintenance; an axial length 1g of the upper support is greater than an axial length Is of the lower support, where ls=(3.8~4.2)D, ls=(1.5~2.0)D, and D is a diameter of an impeller at a front end of the bulb.

[0014] Furthermore, a distance from one side of the upper support or one side of the lower support adjacent to an impeller to a center of the impeller is 15=(1.5~2.0)D, where D is a diameter of the impeller, for shifting positions of the upper support and the lower support backward relative to the center of the impeller, which can reduce impact losses of the fluid and improve operational efficiency of the device.

[0015] Furthermore, one end of the diversion pier is in a shape of a step, with the upper part of the step connected to the upper support and the lower part of the step connected to the lower support, an axial length of the upper part of the step of the diversion pier is 17=(4.5-5.5)D, an axial length of the lower part of the step of the diversion pier is 19=(6.8-7.7)D, and le+ h= h+ b.

[0016] Furthermore, a front half of the tail cone section connected to the cylindrical section is a hollow steel structure, and a rear half of the tail cone section is a concrete structure.

[0017] The present invention has the following advantages.

[0018] 1. The large bulb tubular pump device configured for suppressing tail vortex structures described in the present invention provides an effective support structure for the lengthened bulb by integrating the tail of the bulb with the diversion pier, and further enhances the mechanical strength and stability of the entire device. The reasonable design of the diversion pier ensures that no obvious local vortices are generated when the fluid passes through this region, while improving the durability of the equipment.

[0019] 2. The large bulb tubular pump device configured for suppressing tail vortex structures described in the present invention has a significantly extended length of the tail cone section of the bulb, which significantly mitigates the flow separation and vortices at the tail of the bulb, reduces energy loss in a wake region, guides the flow field more smoothly, and enhances overall hydraulic performance. The upper and lower support structure not only extends the effective length of the support, but also optimizes flow diversion while supporting the bulb. This upper and lower support structure can effectively suppress residual circumferential velocities at outlets of the guide vanes, thereby reducing formation of vortices and resulting energy loss.

[0020] 3. In the large bulb tubular pump device configured for suppressing tail vortex structures described in the present invention, the integration of the upper and lower support structure and the diversion pier evenly divides each of the bulb flow passage and the outlet flow passage into two parts, which can effectively suppress the flow deflection, avoid the adverse flow patterns in the flow field, and ensure that the fluid flows out stably and efficiently along the predetermined path.

[0021] 4. In the large bulb tubular pump device configured for suppressing tail vortex structures described in the present invention, the position of the support structure is shifted backward relative to the impeller, which can reduce the impact losses of the fluid. The bulb is truncated at the position where it is integrated with the diversion pier, which reduces both the length and weight of the bulb on the premise of ensuring the flow stability, and lowers the manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to provide a clearer explanation of the embodiments of the present invention or the technical solutions in the prior art, a brief introduction will be given to the accompanying drawings required for the description of the embodiments or the prior art. The accompanying drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, it is obvious that other drawings can be obtained based on these drawings without creative labor.

[0023] FIG. 1 is a schematic structural diagram of a bulb tubular pump in the prior art.

[0024] FIG. 2 is a schematic structural diagram of a large bulb tubular pump device configured for suppressing tail vortex structures according to the present invention.

[0025] FIG. 3 is a schematic structural diagram of a bulb according to the present invention.

[0026] FIG. 4 is a schematic structural diagram of upper and lower supports and a diversion pier according to the present invention.

[0027] FIG. 5 is a velocity flow field distribution diagram of a bulb tubular pump device in the prior art.

[0028] FIG. 6 is a velocity flow field distribution diagram of a bulb tubular pump device according to the present invention.

[0029] FIG. 7 is a schematic diagram of tail vortices at a tail of a bulb of a bulb tubular pump in the prior art.

[0030] FIG. 8 is a schematic diagram of tail vortices at a tail of a bulb of a bulb tubular pump device designed in the present invention.

[0031] In the drawings:

[0032] 1-Inlet flow passage; 2-Impeller flow passage; 3-Guide vane flow passage; 4-Bulb flow passage; 5-Outlet flow passage; 6-Inlet diversion pier; 7-Impeller; 8-Guide vane; 9-Upper support; 10-Diversion pier; 11-Lower support; 12-Bulb. 12-1-Guide vane diffuser section; 12-2-Cylindrical section; 12-3-Tail cone section. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0034] In the description of the present invention, it should be understood that terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "axial", "radial", "vertical", "horizontal", "inside", "outside", and other directional or positional relationships referred to are based on the directional or positional relationships shown in the accompanying drawings, only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 to the present invention. In addition, terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implying the number of technical features indicated. Thus, features limited to "first" and "second" may each explicitly or implicitly include one or more of the features. In the description of the present invention, "a plurality of' means two or more, unless otherwise specifically limited.

[0035] In the present invention, unless otherwise specified and limited, terms such as "mount", "connected", "connect", and "fix" should be broadly understood, for example, there may be a fixed connection, a detachable connection, or an integral connection; there may be a mechanical connection or an electrical connection; there may be a direct connection, an indirect connection through an intermediate medium, or an internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0036] As shown in FIG. 1, a structure of a bulb tubular pump in the prior art includes an inlet flow passage 1, an impeller flow passage 2, a guide vane flow passage 3, a bulb flow passage 4, and an outlet flow passage 5 that are in communication sequentially in a flow direction. The inlet flow passage 1 is configured with an inlet diversion pier 6, and a bulb 12 is supported in the bulb flow passage 4 by an upper support 9 and a lower support 11. One end of the bulb 12 is configured with guide vanes 8, and the guide vanes 8 are located in the guide vane flow passage 3. A rotatable impeller 7 is mounted at one end of the bulb 12, and the impeller 7 is located in the impeller flow passage 2. A diversion pier 10 is placed in the outlet flow passage 5, located in front of the bulb 12, and not connected to the diversion pier 10, thus producing complex vortices. Moreover, a ratio of a length of a tail of the existing bulb 12 to a maximum diameter of the bulb typically ranges from 0.5 to 1.5. The bulb 12 is configured with a power device, and the power device includes a motor, a rotating shaft, a coupling, a power supply device, and the like. A multi-stage motor is adopted as the motor, and a three-phase AC power supply is adopted for power supply.

[0037] As shown in FIG. 2, in a large bulb tubular pump device configured for suppressing tail vortex structures according to the present invention, one end of the diversion pier 10 extends to a contour of the tail of the bulb 12, which can reduce flow losses between the diversion pier 10 and the tail of the bulb 12, and ensure that no obvious local flow loss occurs when a fluid passes through this region, while improving durability of equipment.

[0038] As shown in FIG. 3, an extension line of the contour of the tail of the bulb 12 is tangent to two side surfaces of the diversion pier 10. A length of a tail cone section 12-3 of the bulb is greatly extended, which significantly mitigates flow separation and vortices at the tail of the bulb, reduces energy loss in a wake region, guides the flow field more smoothly, and enhances overall hydraulic performance, thereby suppressing generation of tail vortices. The bulb 12 includes a guide vane diffuser section 12-1, a cylindrical section 12-2, and a tail cone section 12-3. The guide vane diffuser section 12-1, the cylindrical section 12-2, and the tail cone section 12-3 are connected sequentially in the flow direction. A surface of the guide vane diffuser section 12-1 is configured to mount guide vanes 8, the cylindrical section 12-2 is configured to accommodate a power unit, and one end of the diversion pier 10 extends to the tail cone section 12-3.

[0039] A front half of the tail cone section 12-3 connected to the cylindrical section 12-2 is a hollow steel structure, and a rear half of the tail cone section 12-3 is a concrete structure, which provides high structural strength and a relatively low economic cost.

[0040] A minimum distance from a tangent point between an extension line of the tail cone section 12-3 and the diversion pier 10 to the cylindrical section 12-2 is I4, and a diameter of the tangent point position is d2, meeting the following relations: l4=(6~9)d, d2=(0.2~0.6)d,

[0041] where d is an outer diameter of the cylindrical section 12-2, and a length of the tail cone section (12-3) is 12=0.5 14.

[0042] The bulb tubular pump unit described in the present invention is a large or extra-large bulb tubular pump unit, and the ratio of the length of the tail of the bulb to the diameter of the bulb exceeds 3. Therefore, the length of the tail cone section 12-3 is 12=0.5 I4, which means that the length of the tail cone section 12-3 is 12=(3-4.5)d. The bulb 12 described in the present invention is a bulb of the large or extra-large bulb tubular pump unit.

[0043] As shown in FIG. 4, the bulb 12 is supported in the bulb flow passage 4 by the upper support 9 and the lower support 11. Upper and lower parts of one end of the diversion pier 10 are respectively connected to the upper support 9 and the lower support 11, to evenly divide each of the bulb flow passage 4 and the outlet flow passage 5 into two parts to suppress flow deflection. The upper support 9 and the lower support 11 not only extend the effective length of the support, but also optimize flow diversion while supporting the bulb. This upper and lower support structure can effectively suppress residual circumferential velocities at outlets of the guide vanes, thereby reducing formation of vortices and resulting energy loss.

[0044] Both the upper support 9 and the lower support 11 are hollow structures, and the hollow structures of the upper support 9 and the lower support 11 are respectively in communication with an interior of the cylindrical section 12-2 of the bulb 12, which can facilitate maintenance personnel to enter the bulb 12 for maintenance. An axial length h of the upper support 9 is greater than an axial length Is of the lower support 11, where 16=(3.8~4.2)D, ls=(1.5~2.0)D, and D is a diameter of the impeller 7 at a front end of the bulb 12.

[0045] As shown in FIG. 4, a distance from a left side of the upper support 9 or a left side of the lower support 11 adjacent to an impeller 7 to a center of the impeller 7 is 15=(1.5~2.0)D, where D is a diameter of the impeller 7. Compared with the structure in the prior art, the position of the support structure of the present invention is shifted backward relative to the impeller, which can reduce impact losses of the fluid and improve operational efficiency of the device. One end of the diversion pier 10 is in a shape of a step, with the upper part of the step connected to the upper support 9 and the lower part of the step connected to the lower support 11. An axial length of the upper part of the step of the diversion pier 10 is 17=(4.5-5.5)D, an axial length of the lower part of the step of the diversion pier 10 is 19=(6.8-7.7)D, and le+ h= h+ I9. The diversion pier 10 is made of concrete, which can reduce costs and enhance the structural strength. A thickness ho of the upper support 9, lower support 11, and diversion pier 10 is equal to the diameter d2 at the tangent point position of the extension line of the tail cone section.

[0046] The tail of the bulb 12 is integrated with the diversion pier 10, and the diversion pier is utilized to provide effective support for the tail of the lengthened bulb, and to enhance the mechanical strength and stability of the overall device. The integration of the upper support 9, the lower support 11, and the diversion pier 10 evenly divides each of the bulb flow passage and the outlet flow passage into two parts, which can effectively suppress the flow deflection, avoid the adverse flow patterns in the flow field, and ensure that the fluid flows out stably and efficiently along a predetermined path.

[0047] When the system is operating, the motor drives the impeller 7 of the pump device to rotate. The fluid enters through the inlet flow passage 1, is pressurized by the impeller, and enters the guide vane flow passage 3. The guide vanes recover the circulation of the fluid to reduce helical motion of the fluid. Subsequently, the fluid enters the bulb flow passage 4, passes through the bulb 12, the upper support 9, the lower support 11, the diversion pier 10, and the bulb flow passage 4 to achieve flow diversion and diffusion effects, and flows out from the outlet flow passage 5.

[0048] In this case, the diameter of the impeller is 400 mm, an impeller rotational speed is 875 rpm, an inlet flow rate is 580 L / s, an overall length of the flow passages is 8.4 m, and a head is 2.85 m. The dimensions of the bulb are as follows: 11=0.43 m, d=0.41 m, 12=1.875 m, d2=0.12 m, and 14=3.75 m. The dimensions of the upper and lower supports and the diversion pier are as follows: 16=1.73 m, 17=2.03 m, h=0.72 m, 19=3.04 m, and ho=O. 12 m. The distance from the support to the center of the impeller is 15=0.62 m.

[0049] In this case, conversion is carried out in accordance with the similarity criteria. For a prototype unit, the diameter of the impeller is 5.25 m, the rotational speed is 62.5 rpm, the design point head is 2.5 m, and the inlet flow rate is 100 m3 / s, indicating that the prototype unit belongs to an extra-large bulb tubular pump unit.

[0050] FIG. 5 and FIG. 6 show velocity contour plots and vector diagrams on axial meridian planes for large bulb tubular pump devices adopting the traditional bulb structure and the present invention respectively in this case. It can be clearly seen that, as shown in FIG. 5 and FIG. 7, when the traditional bulb structure is used, the velocity distribution of the tail flow field is uneven, there is an obvious large vortex region at the tail of the bulb, and the flow deflection is also quite severe. As shown in FIG. 6 and FIG. 8, the bulb tubular pump designed according to the present invention has a uniform velocity distribution in the tail flow field, without obvious vortices or backflow, indicating a significant improvement in the flow pattern. By comparing hydraulic losses and efficiency, it can be concluded that in the bulb tubular pump device using the present invention, hydraulic losses in the bulb flow passage and the outlet flow passage are significantly reduced, resulting in an overall efficiency improvement of 8.6%.

[0051] It should be understood that although this specification is described according to various embodiments, not each of the embodiments merely contains an independent technical solution. The description in this specification is only for clarity, and those skilled in the art should consider the specification as a whole. The technical solutions in the various embodiments can also be appropriately combined to form other embodiments that those skilled in the art can understand.

[0052] The series of detailed explanations listed above are only specific explanations of the feasible embodiments of the present invention, and they are not intended to limit the scope of protection of the present invention. Any equivalent embodiments or variations that do not depart from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A large bulb tubular pump device configured for suppressing tail vortex structures, comprising a bulb (12) located in a bulb flow passage (4) and a diversion pier (10) located in an outlet flow passage (5), the diversion pier (10) being located behind the bulb (12), characterized in that one end of the diversion pier (10) extends to a contour of a tail of the bulb (12), for reducing flow losses between the diversion pier (10) and the tail of the bulb (12);an extension line of the contour of the tail of the bulb (12) is tangent to the diversion pier (10) to suppress generation of tail vortices;the bulb (12) is supported in the bulb flow passage (4) by an upper support (9) and a lower support (11), and an upper part and a lower part of the one end of the diversion pier (10) are respectively connected to the upper support (9) and the lower support (11), to evenly divide each of the bulb flow passage (4) and the outlet flow passage (5) into two parts to suppress flow deflection;the bulb (12) comprises a guide vane diffuser section (12-1), a cylindrical section (12-2), and a tail cone section (12-3), and the guide vane diffuser section (12-1), the cylindrical section (12-2), and the tail cone section (12-3) are connected sequentially in a flow direction, a surface of the guide vane diffuser section (12-1) is configured to mount guide vanes (8), the cylindrical section (12-2) is configured to accommodate a power unit, and the one end of the diversion pier (10) extends to the tail cone section (12-3); anda minimum distance from a tangent point between an extension line of the tail cone section (12-3) and the diversion pier (10) to the cylindrical section (12-2) is U, and a diameter of a tangent point position is d2, meeting the following relations:l4=(6~9)d,d2=(0.2~0.6)d,wherein d is an outer diameter of the cylindrical section (12-2), anda length of the tail cone section (12-3) is 12=0.5 I4.

2. The large bulb tubular pump device configured for suppressing the tail vortex structures according to claim 1, characterized in that the upper support (9) and the lower support (11) are hollow structures, the hollow structures of the upper support (9) and the lower support (11) are respectively in communication with an interior of the cylindrical section (12-2) of the bulb (12), and an axial length U of the upper support (9) is greater than an axial length Is of the lower support (11), wherein 16=(3.8~4.2)D, ls=(1.5~2.0)D, and D is a diameter of an impeller (7) at a front end of the bulb (12).

3. The large bulb tubular pump device configured for suppressing the tail vortex structures according to claim 1, characterized in that a distance from one side of the upper support (9) or one side of the lower support (11) adjacent to an impeller (7) to a center of the impeller (7) is 15=(1.5~2.0)D, wherein D is a diameter of the impeller (7).

4. The large bulb tubular pump device configured for suppressing the tail vortex structures according to claim 2, characterized in that the one end of the diversion pier (10) is in a shape of a step, with the upper part of the step connected to the upper support (9) and the lower part of the step connected to the lower support (11), an axial length of the upper part of the step of the diversion pier (10) is 17=(4.5-5.5)D, an axial length of the lower part of the step of the diversion pier (10) is 19=(6.8-7.7)D, and k+ h= h+ I9.

5. The large bulb tubular pump device configured for suppressing the tail vortex structures according to claim 1, characterized in that a front half of the tail cone section (12-3) connected to the cylindrical section (12-2) is a hollow steel structure, and a rear half of the tail cone section (12-3) is a concrete structure.

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