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 channel and a guide pier located in a water discharge flow channel. The guide pier is located behind the bulb body, and one end of the guide pier extends to the contour of the tail of the bulb body to reduce the flow loss between the guide pier and the tail of the bulb body. An extension line of the contour of the tail of the bulb body is tangent to the thickness of the guide pier, to suppress the generation of tail vortices. In the present invention, by integrating the tail of the bulb body with the guide pier, not only is an effective supporting structure provided for the lengthened bulb body, but the mechanical strength and stability of the entire device are also enhanced. The rational design of the guide pier ensures that no significant local flow loss is generated when a fluid passes through the region, thereby improving durability of the device.

Description

A large bulb-shaped cross-flow pump device capable of suppressing tail vortex structure Technical Field

[0001] This invention relates to the field of bulb-type flow pump technology, and in particular to a large bulb-type flow pump device that can suppress tail vortex structures. Background Technology

[0002] Large bulb-type axial flow pumps, as highly efficient hydraulic machines, are widely used in large-scale water conservancy projects, urban water supply, and sewage treatment. In these applications, the stability and efficiency of the pump unit are crucial to the operation of the entire system. However, during operation, the flow field at the tail of the axial flow pump often generates complex vortex structures. This is especially true in large and even extra-large axial flow pump units, where the vibration and noise caused by the tail vortices are more severe, significantly impacting the stability of the system. Furthermore, these vortices also lead to hydraulic losses, affecting the overall efficiency of the pump and thus adversely affecting the long-term operation of the unit.

[0003] In existing large bulb-type axial flow pump units, specific bulb body structures are typically used to reduce vortices. The ratio of the bulb body's tail length to its maximum diameter is usually between 0.5 and 1.5. However, for large or extra-large bulb-type axial flow pump units, it is often impossible to effectively eliminate tail vortices. Increasing the length of the bulb tail can reduce vortices caused by flow separation to some extent, but it leads to an increase in the size and weight of the bulb, posing a significant challenge to bulb body fixation and structural stability. Furthermore, due to the influence of components such as the bulb body support structure, undesirable flow patterns such as flow deviation and secondary flow are also quite pronounced. Therefore, designing a more efficient and structurally simple tail vortex suppression structure has become an urgent problem to be solved in the field of large bulb-type axial flow pumps. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a large bulb-shaped cross-flow pump device that can suppress tail vortex structures. By integrating the tail of the bulb body with the guide pier, not only is an effective support structure provided for the extended bulb body, but the mechanical strength and stability of the entire device are also enhanced. The rational design of the guide pier ensures that no significant local flow loss occurs when the fluid passes through this area, while also improving the durability of the equipment. The extension line of the bulb body tail profile is tangent to the thickness of the guide pier, which can effectively reduce the vortex intensity of the wake field, thereby improving the operating efficiency of the pump device, reducing vibration and noise, and extending the service life of the equipment.

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

[0006] A large bulb-shaped cross-flow pump device for suppressing tail vortex structure includes a bulb body located in a bulb body flow channel and a guide pier located in a water outlet flow channel. The guide pier is located behind the bulb body, and one end of the guide pier extends to the outline of the tail of the bulb body to reduce flow loss between the guide pier and the tail of the bulb body.

[0007] Furthermore, the extended line of the tail contour of the bulb body is tangent to the guide pier, which is used to suppress the generation of tail vortices.

[0008] Furthermore, the bulb body is supported in the bulb body flow channel by an upper support and a lower support. The upper and lower parts of one end of the guide pier are connected to the upper support and the lower support respectively, which evenly divides the bulb body flow channel and the water outlet flow channel into two parts to suppress flow deviation, avoid undesirable flow conditions in the flow field, and ensure that the fluid flows out stably and efficiently along the predetermined path.

[0009] Furthermore, the bulb body includes a guide vane diffuser section, a cylindrical section, and a tail cone section, which are connected sequentially in the flow direction; the surface of the guide vane diffuser section is used to install guide vanes, the cylindrical section is used to house the power unit, and one end of the flow guide extends to the tail cone section.

[0010] Furthermore, the minimum distance from the point of tangency between the extended line of the tail cone section and the guide pier to the cylindrical section is l4, and the diameter at the point of tangency is d2, satisfying the following relationship:

[0011] Where: d is the outer diameter of the cylindrical section; the length of the tail cone section l2 = 0.5l4.

[0012] The length of the tail cone section, l2, is (3~4.5)d. This significantly extends the length of the bulb body, slowing down the diffusion and separation of the fluid in the flow channel and effectively suppressing the generation of tail vortices. The bulb body is cut off at the point where it merges with the guide pier, reducing the length and weight of the bulb while ensuring flow stability, thus lowering manufacturing costs.

[0013] Furthermore, both the upper and lower supports are hollow structures, and the hollow structures of the upper and lower supports are respectively connected to the cylindrical section of the bulb body to facilitate equipment maintenance; the axial length l6 of the upper support is greater than the axial length l7 of the lower support, where l6 = (3.8~4.2)D, l8 = (1.5~2.0)D, and D is the impeller diameter at the front end of the bulb body.

[0014] Furthermore, the distance l5 from the upper support side or the lower support side to the impeller center is (1.5~2.0)D, where D is the impeller diameter. The purpose is to shift the position of the upper and lower supports relative to the impeller center backward, which can reduce the impact loss of the fluid and improve the operating efficiency of the device.

[0015] Furthermore, one end of the guide pier is stepped, with the upper part of the stepped pier connected to the upper support and the lower part of the stepped pier connected to the lower support. The axial length of the upper part of the stepped pier is l7 = (4.5~5.5)D, and the axial length of the lower part of the stepped pier is l9 = (6.8~7.7)D, and l6+l7 = l8+l9.

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

[0017] The beneficial effects of this invention are as follows:

[0018] 1. The large bulb-shaped cross-flow pump device with tail vortex suppression structure described in this invention provides an effective support structure for the extended bulb body by integrating the tail of the bulb body with the guide pier, which also enhances the mechanical strength and stability of the entire device. The reasonable design of the guide pier ensures that no obvious local vortex is generated when the fluid passes through this area, while improving the durability of the equipment.

[0019] 2. The large bulb-shaped cross-flow pump device with tail vortex suppression structure described in this invention significantly extends the length of the bulb body's tail cone, which significantly improves flow separation and vortex phenomena at the tail of the bulb body, reduces energy loss in the wake region, and provides more stable flow field guidance, thereby improving overall hydraulic performance. The upper and lower support structures not only extend the effective length of the support but also optimize flow guidance while supporting the bulb body. This upper and lower support structure can effectively suppress the residual circumferential velocity at the guide vane outlet, thereby reducing the formation of vortices and the resulting energy loss.

[0020] 3. The large bulb-shaped cross-flow pump device with tail vortex structure described in this invention, in which the upper and lower support structures and the guide piers are combined, evenly divides the bulb body flow channel and the water outlet flow channel into two parts, which can effectively suppress the occurrence of flow deviation, avoid undesirable flow state in the flow field, and ensure that the fluid flows out stably and efficiently along the predetermined path.

[0021] 4. The large bulb-type cross-flow pump device for suppressing tail vortex structure described in this invention has a support structure offset rearward from the impeller, which can reduce fluid impact loss. The bulb body is cut off at the point of fusion with the guide pier, reducing the bulb's length and weight while ensuring flow stability, thus lowering manufacturing costs. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are some embodiments of the present invention. For those skilled in the art, it is obvious that other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 is a schematic diagram of the structure of a bulb-shaped cross-flow pump in the prior art.

[0024] Figure 2 is a schematic diagram of the structure of the large bulb-shaped cross-flow pump device that can suppress tail vortex structure according to the present invention.

[0025] Figure 3 is a schematic diagram of the bulb body structure described in this invention.

[0026] Figure 4 is a schematic diagram of the upper and lower support and guide pier structure described in this invention.

[0027] Figure 5 shows the velocity flow field distribution of a conventional bulb-type cross-flow pump device.

[0028] Figure 6 is a velocity flow field distribution diagram of the bulb-shaped cross-flow pump device of the present invention.

[0029] Figure 7 is a schematic diagram of the vortex at the tail of the bulb in a conventional bulb-type cross-flow pump.

[0030] Figure 8 is a schematic diagram of the vortex at the tail of the bulb body of the bulb-shaped cross-flow pump device designed in this invention.

[0031] In the picture:

[0032] 1-Inlet flow channel; 2-Impeller flow channel; 3-Guide vane flow channel; 4-Bulb body flow channel; 5-Outlet flow channel; 6-Inlet guide vane; 7-Impeller; 8-Guide vane; 9-Upper support; 10-Guide vane; 11-Lower support; 12-Bulb body. 12-1-Guide vane diffuser section; 12-2-Cylindrical section; 12-3-Tail cone section. Detailed Implementation

[0033] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. 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 this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0035] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] As shown in Figure 1, the existing bulb-type cross-flow pump structure includes an inlet channel 1, an impeller channel 2, a guide vane channel 3, a bulb body channel 4, and an outlet channel 5 connected sequentially in the flow direction. An inlet guide vane 6 is placed inside the inlet channel 1. The bulb body 12 is mounted inside the bulb body channel 4 via an upper support 9 and a lower support 11. A guide vane 8 is installed on one end of the bulb body 12, located inside the guide vane channel 3. A rotatable impeller 7 is installed at one end of the bulb body 12, located in the impeller channel 2. A guide vane 10 is placed in the outlet channel 5, positioned in front of the bulb body 12, but not connected to it, thus generating complex vortices. Furthermore, the ratio of the tail length of the existing bulb body 12 to its maximum diameter is typically between 0.5 and 1.5. A power unit is installed inside the bulb body 12, including a motor, a shaft, a coupling, and a power supply. The motor is a multi-stage motor, and the power supply is a three-phase AC power supply.

[0037] As shown in Figure 2, the large bulb cross-flow pump device of the present invention, which can suppress tail vortex structure, has one end of the flow guide 10 extending to the outline of the tail of the bulb body 12, which can reduce the flow loss between the flow guide 10 and the tail of the bulb body 12, ensure that the fluid does not generate obvious local flow loss when passing through this area, and improve the durability of the device.

[0038] As shown in Figure 3, the extended line of the tail contour of the bulb body 12 is tangent to the two sides of the guide pier 10. The length of the tail cone section 12-3 of the bulb body is significantly extended, which significantly improves the flow separation and eddy phenomenon at the tail of the bulb body, reduces energy loss in the wake region, and guides the flow field more smoothly, thereby improving the overall hydraulic performance; it is used to suppress the generation of tail eddies. The bulb body 12 includes a guide vane diffuser section 12-1, a cylindrical section 12-2, and a tail cone section 12-3, which are connected sequentially in the flow direction; the surface of the guide vane diffuser section 12-1 is used to install the guide vane 8, the cylindrical section 12-2 is used to house the power unit, and one end of the guide pier 10 extends to the tail cone section 12-3.

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

[0040] The minimum distance from the point of tangency between the extended line of the tail cone section 12-3 and the guide pier 10 to the cylindrical section 12-2 is l4, and the diameter at the point of tangency is d2, satisfying the following relationship:

[0041] Where: d is the outer diameter of cylindrical segment 12-2;

[0042] The bulb-type axial flow pump unit described in this invention is a large or extra-large bulb-type axial flow pump unit, wherein the ratio of the length of the tail of the bulb body to the diameter of the bulb body exceeds 3. Therefore, the length l2 of the tail cone section 12-3 is 0.5l4, which means the length l2 of the tail cone section 12-3 is (3~4.5)d. The bulb body 12 described in this invention is the bulb body of a large or extra-large bulb-type axial flow pump unit.

[0043] As shown in Figure 4, the bulb body 12 is supported in the bulb body flow channel 4 by an upper support 9 and a lower support 11. The upper and lower parts of one end of the guide vane 10 are connected to the upper support 9 and the lower support 11 respectively, dividing the bulb body flow channel 4 and the outlet flow channel 5 into two equal parts to suppress flow deviation. The upper support 9 and the lower support 11 not only extend the effective length of the support, but also optimize the flow while supporting the bulb body. This upper and lower support structure can effectively suppress the residual circumferential velocity at the guide vane outlet, thereby reducing the formation of vortices and the resulting energy loss.

[0044] Both 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 connected to the cylindrical section 12-2 of the bulb body 12, which allows maintenance personnel to easily enter the bulb body 12 for maintenance. The axial length l6 of the upper support 9 is greater than the axial length l7 of the lower support 11, where l6 = (3.8~4.2)D and l8 = (1.5~2.0)D, and D is the diameter of the impeller 7 at the front end of the bulb body 12.

[0045] As shown in Figure 4, the distance l5 from the left side of the upper support 9 and the left side of the lower support 11 to the center of the impeller 7 is (1.5~2.0)D, where D is the diameter of the impeller 7. Compared to existing structures, the support structure of this invention is offset backward from the impeller, which reduces fluid impact loss and improves the operating efficiency of the device. One end of the guide pier 10 is stepped, with the upper part connected to the upper support 9 and the lower part connected to the lower support 11. The axial length l7 of the upper part of the stepped guide pier 10 is (4.5~5.5)D, and the axial length l9 of the lower part is (6.8~7.7)D, where l6+l7=l8+l9. The guide pier 10 is made of concrete, which reduces cost and increases structural strength. The thickness l of the upper support 9, lower support 11, and guide pier 10 is... 10 The diameter d2 is the same as the diameter at the tangent point of the extended line of the coccyx segment.

[0046] The tail of the bulb body 12 is integrated with the guide pier 10, which provides effective support for the extended tail of the bulb body and enhances the mechanical strength and stability of the overall device. The combination of the upper support 9, the lower support 11, and the guide pier 10 evenly divides the bulb body flow channel and the water outlet flow channel into two parts, effectively suppressing the occurrence of flow deviation, avoiding undesirable flow patterns in the flow field, and ensuring that the fluid flows out stably and efficiently along the predetermined path.

[0047] When the system is running, the motor drives the impeller 7 of the water pump to rotate. The fluid enters through the inlet channel 1, is pressurized by the impeller, and then enters the guide vane channel 3. The guide vanes recover the circulation of the fluid and reduce its spiral motion. Subsequently, the fluid enters the bulb body channel 4, and after being guided and diffused by the bulb body 12, upper support 9, lower support 11, guide pier 10, and the bulb body channel 4, it flows out from the outlet channel 5.

[0048] In this case, the impeller diameter is 400mm, the impeller speed is 875rpm, the inlet flow rate is 580L / s, the overall flow channel length is 8.4m, and the head is 2.85m. The dimensions of the bulb body are: l1 = 0.43m, d = 0.41m, l2 = 1.875m, d2 = 0.12m, l4 = 3.75m. The dimensions of the upper and lower supports and the guide piers are: l6 = 1.73m, l7 = 2.03m, l8 = 0.72m, l9 = 3.04m, l...10 =0.12m, and the distance from the support to the center of the impeller is l5 =0.62m.

[0049] This case study uses similarity criteria for conversion. The actual machine has an impeller diameter of 5.25m, a rotational speed of 62.5rpm, a design head of 2.5m, and an inlet flow rate of 100m³ / h. 3 / s, belonging to the extra-large bulb-shaped cross-flow pump unit.

[0050] Figures 5 and 6 show the velocity distribution cloud maps and vector maps of the axial plane of the traditional bulb body structure and the large bulb-shaped cross-flow pump device of this invention. It is evident from Figures 5 and 7 that, with the traditional bulb body structure, the velocity distribution of the flow field at the tail is uneven, with a significant large-scale vortex region and severe flow deviation. As shown in Figures 6 and 8, the bulb-shaped cross-flow pump designed according to this invention exhibits a uniform velocity distribution at the tail, with no obvious vortices or backflow, indicating a significant improvement in flow characteristics. Comparing hydraulic losses and efficiency, it can be seen that the bulb-shaped cross-flow pump device of this invention significantly reduces hydraulic losses in the bulb body flow channel and the outlet flow channel, 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 every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0052] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A large bulb-shaped cross-flow pump device capable of suppressing tail vortex structures, comprising a bulb body (12) located in a bulb body flow channel (4) and a guide pier (10) located in a water outlet flow channel (5), wherein the guide pier (10) is located behind the bulb body (12), characterized in that, The flow guide (10) extends at one end to the outline of the bulb body (12) to reduce the flow loss between the flow guide (10) and the tail of the bulb body (12).

2. The large bulb-shaped cross-flow pump device capable of suppressing tail vortex structure according to claim 1, characterized in that, The extended line of the tail contour of the bulb body (12) is tangent to the guide block (10) to suppress the generation of tail vortex.

3. The large bulb-shaped cross-flow pump device capable of suppressing tail vortex structure according to claim 1, characterized in that, The bulb body (12) is supported in the bulb body flow channel (4) by the upper support (9) and the lower support (11). The upper and lower parts of one end of the guide pier (10) are connected to the upper support (9) and the lower support (11) respectively, so as to evenly divide the bulb body flow channel (4) and the water outlet flow channel (5) into two parts to suppress the flow deviation.

4. The large bulb-shaped cross-flow pump device capable of suppressing tail vortex structure according to claim 3, characterized in that, The bulb body (12) includes a guide vane diffuser section (12-1), a cylindrical section (12-2), and a tail cone section (12-3), which are connected sequentially in the flow direction; the surface of the guide vane diffuser section (12-1) is used to install guide vanes (8), the cylindrical section (12-2) is used to place the power unit, and one end of the guide vane (10) extends to the tail cone section (12-3).

5. The large bulb-shaped cross-flow pump device capable of suppressing tail vortex structure according to claim 4, characterized in that, The minimum distance from the point of tangency between the extended line of the tail cone section (12-3) and the guide pier (10) to the cylindrical section (12-2) is l4, and the diameter at the point of tangency is d2, satisfying the following relationship: l4=(6~9)dd2=(0.2~0.6)d Where: d is the outer diameter of the cylindrical segment (12-2); The length of the tail cone segment (12-3) is l2 = 0.5l4.

6. The large bulb-shaped cross-flow pump device capable of suppressing tail vortex structure according to claim 3, characterized in that, Both 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 connected to the cylindrical section (12-2) of the bulb body (12). The axial length l6 of the upper support (9) is greater than the axial length l7 of the lower support (11), where l6 = (3.8~4.2)D, l8 = (1.5~2.0)D, and D is the diameter of the impeller (7) at the front end of the bulb body (12).

7. The large bulb-shaped cross-flow pump device capable of suppressing tail vortex structure according to claim 3, characterized in that, The distance from one side of the upper support (9) or the lower support (11) to the center of the impeller (7) is l5 = (1.5~2.0)D, where D is the diameter of the impeller (7).

8. The large bulb-shaped cross-flow pump device capable of suppressing tail vortex structure according to claim 6, characterized in that, One end of the guide pier (10) is stepped, with the upper part of the stepped pier connected to the upper support (9) and the lower part of the stepped pier connected to the lower support (11). The axial length of the upper part of the stepped pier (10) is l7 = (4.5~5.5)D, and the axial length of the lower part of the stepped pier (10) is l9 = (6.8~7.7)D, and l6+l7 = l8+l9.

9. The large bulb-shaped cross-flow pump device capable of suppressing tail vortex structure according to claim 4, characterized in that, The front half of the tail cone section (12-3) connected to the cylindrical section (12-2) is a hollow steel structure, and the rear half of the tail cone section (12-3) is a concrete structure.

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