Double-impeller pressure balance type high-lift water pump

Abstract

This utility model provides a dual-impeller pressure-balanced high-lift water pump, which improves the high-pressure stable output efficiency of high-lift, large-size water pumps through a differentiated and synergistic design of the two-stage impellers. It includes a pump body, a main shaft, and a cavity within the pump body. The portion of the cavity near the inlet constitutes the inlet cavity, and the portion near the outlet constitutes the outlet cavity. The main shaft is equipped with a split-flow impeller assembly, including a first-stage impeller and a second-stage impeller. The first-stage impeller has 5-7 blades with an outlet angle β1 = 22° ± 2°. °; the secondary impeller has 9-11 blades, with an exit angle β2 = 18° ± 2°; the blade diameter ratio of the primary impeller to the secondary impeller is 3:2; a flow guide baffle pressure balance chamber is provided between the primary and secondary impellers; the inlet of the flow guide baffle pressure balance chamber is provided with an involute spiral guide groove with a spiral angle α = 25° ± 5°; the flow guide baffle pressure balance chamber is provided with a slag discharge hole with a diameter of 4 mm and an exhaust hole with a diameter of 1.5 mm; a honeycomb damping plate is provided on the outlet side of the flow guide baffle pressure balance chamber.

Description

Technical Field

[0001] This utility model relates to the field of large-size water pumps, specifically to a double-impeller pressure-balanced high-lift water pump. Background Technology

[0002] In water supply systems, industrial circulation, and farmland irrigation, high-lift water pumps are crucial equipment. Traditional single-stage water pumps are limited by cavitation performance and impeller structure; directly increasing the size of the pump and impeller would also increase the chamber space, limiting power and making it difficult to exceed 150m in head. While two-stage pump designs exist in current technology, they still suffer from the following common drawbacks:

[0003] 1. Pressure imbalance problem: The lack of a pressure buffer structure between the two impellers leads to strong fluid pulsation between stages, causing high-frequency vibration of the bearings and shortening the life of the mechanical seal;

[0004] 2. Low energy efficiency: The impeller typically has 5-7 blades, resulting in insufficient impeller suction and mismatched pressure rise capacity, leading to generally low system efficiency.

[0005] 3. When the temperature changes abruptly, the end face specific pressure becomes uncontrolled, which can easily lead to leakage;

[0006] 4. The pump body support is not rigid enough, and it needs to be readjusted when switching power sources. Utility Model Content

[0007] The purpose of this invention is to provide a dual-impeller pressure-balanced high-lift water pump, which can improve the high-pressure stable output efficiency of high-lift, large-size water pumps through the differentiated and coordinated design of the dual-stage impellers.

[0008] The embodiments of this utility model are implemented as follows:

[0009] A dual-impeller pressure-balanced high-lift water pump includes a pump body, a main shaft, and a cavity disposed within the pump body. The portion of the cavity near the inlet end forms the inlet chamber, and the portion near the outlet forms the outlet chamber, wherein:

[0010] The main shaft is equipped with a split-flow impeller assembly, including a first-stage impeller and a second-stage impeller; the first-stage impeller has 5-7 blades with a blade exit angle β1=22°±2°; the second-stage impeller has 9-11 blades with a blade exit angle β2=18°±2°.

[0011] The blade diameter ratio of the primary impeller to the secondary impeller is 3:2; a flow guide baffle pressure balance chamber is provided between the primary impeller and the secondary impeller;

[0012] The inlet of the pressure balance chamber of the flow guide baffle is provided with an involute spiral guide groove with a spiral angle α = 25° ± 5°; the pressure balance chamber of the flow guide baffle is provided with a slag discharge hole with a diameter of 4 mm and an exhaust hole with a diameter of 1.5 mm; the outlet side of the pressure balance chamber of the flow guide baffle is provided with a honeycomb damping plate with a porosity of 40%.

[0013] In a preferred embodiment of the present invention, the hub of the first-stage impeller is provided with 6 radial reinforcing ribs, the thickness of which is 1.2 times the maximum thickness of the blade, and the height of which is 1 / 3 of the depth of the flow channel.

[0014] In a preferred embodiment of this utility model, the honeycomb damping plate is made of TC4 titanium alloy, with a regular hexagonal hole shape, a hole diameter of 1.2 mm, and a plate thickness of 2 mm.

[0015] In a preferred embodiment of the present invention, the sealing ring end face of the pump body is provided with a microporous structure, the micropores are distributed in concentric circles, and the center of the outermost micropores is 0.8mm away from the edge of the sealing surface.

[0016] In a preferred embodiment of this utility model, a shape memory alloy compensation ring is embedded in the groove on the back of the sealing ring.

[0017] At room temperature, the compensation ring and the groove are fitted with a clearance of 0.03mm.

[0018] When the temperature reaches 80℃, the compensation ring and the groove form an interference fit.

[0019] In a preferred embodiment of this utility model, the height difference between the water inlet end and the main shaft mounting plane is 280mm.

[0020] In a preferred embodiment of this utility model, the axis of the water inlet is inclined at a 15° angle to the horizontal plane.

[0021] In a preferred embodiment of this utility model, the bottom of the pump body is provided with a front and rear double support structure, and the water pump can be placed independently and vertically when no power source is installed.

[0022] In a preferred embodiment of this utility model, the depth of the water inlet of the above-mentioned water outlet is 35mm.

[0023] In a preferred embodiment of this utility model, the pump body is a cast iron pump.

[0024] The beneficial effects of this utility model embodiment are:

[0025] 1. The new water pump adopts a two-stage impeller collaborative design. The different number of blades and outlet angle design of the first and second stage impellers form a pressure gradient. At the same time, the first and second stage impellers adopt a 3:2 diameter ratio to achieve efficient energy transfer and solve the problem of limited head of a single impeller.

[0026] 2. A flow guide baffle balance chamber is designed between the primary and secondary impellers. Its involute spiral guide groove design reduces turbulent energy loss. A honeycomb damping plate is designed at the outlet of the flow guide baffle pressure balance chamber to suppress pressure pulsation. The slag discharge hole designed at the top and the exhaust hole designed at the bottom are dual channels to ensure the cleanliness of the chamber. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of a double-impeller pressure-balanced high-lift water pump according to an embodiment of the present utility model;

[0029] Figure 2 This is a top view of the first-stage impeller structure according to an embodiment of the present invention;

[0030] Figure 3 This is a bottom view of the secondary impeller structure according to an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the pressure balance chamber structure of the flow guide baffle in an embodiment of this utility model;

[0032] icon:

[0033] Pump body 100; inlet chamber 110; outlet chamber 120; main shaft 130; primary impeller 140; radial reinforcing rib 141; secondary impeller 150; flow guide baffle pressure balance chamber 160; involute spiral guide groove 161; slag discharge hole 162; vent hole 163; honeycomb damping plate 164; shape memory alloy compensation ring 170; front and rear double support structure 180. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0036] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0037] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0038] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0039] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 utility model based on the specific circumstances.

[0040] First Embodiment

[0041] Please refer to Figure 1-4This embodiment provides a dual-impeller pressure-balanced high-lift water pump, including a pump body 100, a main shaft 130, and a cavity disposed within the pump body 100. The portion of the cavity near the inlet end forms an inlet chamber 110, and the portion near the outlet forms an outlet chamber 120. The main shaft 130 is provided with a flow-dividing impeller assembly, including a primary impeller 140 and a secondary impeller 150. The primary impeller 140 is located in the inlet chamber 110, and the secondary impeller 150 is located in the outlet chamber 120.

[0042] The first-stage impeller 140 has 5-7 blades with a blade outlet angle β1=22°±2°. It creates a low-pressure zone with high flow rate in the inlet chamber 110. At the same time, the fewer blades and the large outlet angle design can reduce inlet backflow loss and enhance steam turbidity protection.

[0043] The secondary impeller 150 has 9-11 blades with an outlet angle β2 = 18° ± 2°. It creates a high-pressure zone in the outlet chamber 120 for stable output. The use of a larger number of blades and a smaller outlet angle enhances centrifugal force, suppresses boundary layer separation, and increases head. The blade diameter ratio of the primary impeller 140 to the secondary impeller 150 is 3:2. The primary impeller with a larger diameter captures kinetic energy, while the secondary impeller with a smaller diameter pressurizes it, thus achieving efficient kinetic energy transfer.

[0044] A flow guide baffle pressure balance chamber 160 is provided between the primary impeller 140 and the secondary impeller 150, located between the inlet chamber 110 and the outlet chamber 120, to ensure axial force balance, symmetrically receive the back pressure of the two impellers, and counteract the hydraulic thrust.

[0045] The inlet of the pressure balance chamber 160 of the flow guide baffle is provided with an involute spiral guide groove 161 with a spiral angle α=25°±5°. The involute shape smoothly guides the fluid to change direction, eliminates the eddy current of the sudden expansion structure, and reduces turbulent energy consumption.

[0046] The pressure balance chamber 160 of the flow guide baffle is provided with a slag discharge hole 162 with a diameter of 4mm. The slag discharge hole 162 is provided for venting and preventing air lock. The venting hole 163 with a diameter of 1.5mm is provided for slag discharge and preventing sedimentation. The 2.5mm hole diameter difference realizes gas-solid separation.

[0047] The outlet side of the pressure balance chamber 160 of the flow guide baffle is provided with a honeycomb damping plate 164, which has a hexagonal array of holes to form acoustic impedance, consume fluid pressure wave energy, and has a porosity of 40% to attenuate the pressure pulsation amplitude.

[0048] Furthermore, the hub of the first-stage impeller 140 is provided with 6 radial reinforcing ribs 141. The thickness of the reinforcing ribs is 1.2 times the maximum thickness of the blades, and the height of the reinforcing ribs is 1 / 3 of the depth of the flow channel. The evenly distributed ribs are used to counteract the centrifugal force of high-speed rotation and can improve the impeller's resistance to deformation.

[0049] The 164 honeycomb damping plate is made of TC4 titanium alloy with regular hexagonal holes, a hole diameter of 1.2mm, and a plate thickness of 2mm, which is superior to circular holes and can improve the turbulent kinetic energy dissipation rate.

[0050] The sealing ring end face of the pump body 100 is provided with a microporous structure. The micropores are distributed in concentric circles. The center of the outermost micropore is 0.8mm away from the edge of the sealing surface, which is used to control the temperature rise of the end face.

[0051] The back groove of the sealing ring is embedded with a shape memory alloy compensation ring 170. At room temperature, the compensation ring and the groove are fitted with a clearance of 0.03mm to allow space for thermal expansion. When the temperature reaches 8℃, the compensation ring and the groove form an interference fit, which provides self-compensation sealing at high temperatures and can maintain a constant end face specific pressure under operating conditions of 0-120℃.

[0052] The height difference between the water inlet end and the mounting plane of the main shaft 130 is 280mm. Compared with the original structure, the suction lift is increased and the self-priming time is reduced. The self-priming time of the original structure is >45s, while the self-priming time of the newly designed water pump is <18s.

[0053] The axis of the water inlet is inclined at a 15° angle to the horizontal plane, which makes installation easier and helps to maintain the natural state of the water inlet pipe.

[0054] The pump body 100 has a front and rear double support structure 180 at its bottom, allowing the pump to be placed vertically independently when no power source is installed, thus improving the interchangeability of the power type. The specific support structure used is not limited.

[0055] The water inlet depth of the outlet is 35mm, which makes it easier to add water for irrigation.

[0056] The pump body 100 is a cast iron pump. The damping characteristics of cast iron can absorb vibration energy, making it suitable for large-size water pumps in this embodiment.

[0057] This specification describes examples of embodiments of the present invention, but does not imply that these embodiments illustrate and describe all possible forms of the present invention. It should be understood that the embodiments in the specification can be implemented in various alternative forms. The drawings are not necessarily drawn to scale; some features may be enlarged or reduced to show details of specific components. The specific structural and functional details disclosed should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to implement the present invention in various forms. Those skilled in the art will understand that multiple features illustrated and described with reference to any of the drawings can be combined with features illustrated in one or more other drawings to form embodiments not explicitly illustrated or described. The illustrated combinations of features provide representative embodiments for typical applications. However, various combinations and variations of features consistent with the teachings of the present invention may be used as needed for specific applications or implementations.

[0058] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A double-impeller pressure-balanced high-lift water pump, comprising a pump body, a main shaft, and a cavity disposed within the pump body, wherein the portion of the cavity near the inlet end constitutes an inlet chamber, and the portion near the outlet end constitutes an outlet chamber, characterized in that: The main shaft is equipped with a split-flow impeller assembly, including a first-stage impeller and a second-stage impeller; the first-stage impeller has 5-7 blades with a blade exit angle β1=22°±2°; the second-stage impeller has 9-11 blades with a blade exit angle β2=18°±2°. The blade diameter ratio of the first-stage impeller to the second-stage impeller is 3:2; a flow guide baffle pressure balance chamber is provided between the first-stage impeller and the second-stage impeller; The inlet of the pressure balance chamber of the flow guide baffle is provided with an involute spiral guide groove with a spiral angle α = 25° ± 5°; the pressure balance chamber of the flow guide baffle is provided with a slag discharge hole with a diameter of 4 mm and an exhaust hole with a diameter of 1.5 mm; the outlet side of the pressure balance chamber of the flow guide baffle is provided with a honeycomb damping plate with a porosity of 40%.

2. The double-impeller pressure-balanced high-lift water pump according to claim 1, characterized in that, The hub of the first-stage impeller is provided with 6 radial reinforcing ribs. The thickness of the reinforcing ribs is 1.2 times the maximum thickness of the blades, and the height of the reinforcing ribs is 1 / 3 of the depth of the flow channel.

3. The double-impeller pressure-balanced high-lift water pump according to claim 1, characterized in that, The honeycomb damping plate is made of TC4 titanium alloy, with regular hexagonal holes, a hole diameter of 1.2mm, and a plate thickness of 2mm.

4. The double-impeller pressure-balanced high-lift water pump according to claim 1, characterized in that, The sealing ring end face of the pump body is provided with a microporous structure. The micropores are distributed in concentric circles, and the center of the outermost micropore is 0.8mm away from the edge of the sealing surface.

5. The double-impeller pressure-balanced high-lift water pump according to claim 4, characterized in that, A shape memory alloy compensation ring is embedded in the groove on the back of the sealing ring; At room temperature, the compensation ring and the groove are fitted with a clearance of 0.03 mm. When the temperature reaches 80°C, the compensation ring and the groove form an interference fit.

6. The double-impeller pressure-balanced high-lift water pump according to claim 1, characterized in that, The height difference between the water inlet end and the main shaft mounting plane is 280mm.

7. The double-impeller pressure-balanced high-lift water pump according to claim 1, characterized in that, The axis of the water inlet is inclined at a 15° angle to the horizontal plane.

8. The double-impeller pressure-balanced high-lift water pump according to claim 1, characterized in that, The pump body is equipped with a front and rear double support structure at the bottom, and the water pump can be placed independently and vertically when no power source is installed.

9. The double-impeller pressure-balanced high-lift water pump according to claim 1, characterized in that, The depth of the water inlet at the outlet is 35mm.

10. The double-impeller pressure-balanced high-lift water pump according to claim 1, characterized in that, The pump body is a cast iron pump.

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