High pressure multi-stage centrifugal pump with streamlined pump cover

Abstract

The high-pressure multistage centrifugal pump with streamlined pump cover comprises an inlet guide vane installed on the inner side wall of the inlet of the inlet pump cover and spaced from the flow guide cone, first and second guide vanes respectively arranged on the two opposite sides of the middle partition plate, a booster ring connected to the outlet side of the outlet partition plate and forming a tapered flow channel with the outlet partition plate, the tapered flow channel being uniformly provided with a plurality of booster blades, a double-hump streamlined structure arranged on the inner side wall of the inlet of the inlet pump cover, and a composite streamlined structure arranged on the inner side wall of the outlet pump cover. Compared with the prior art, the high-pressure multistage centrifugal pump with streamlined pump cover effectively solves the problems of low efficiency and energy consumption, high cavitation, vibration and noise, and narrow high-efficiency operation range by optimizing the streamlined structure of the inlet pump cover and the outlet pump cover.

Description

Technical Field

[0001] This invention relates to the field of fluid machinery technology, specifically to a centrifugal pump, and more specifically to a high-pressure multistage centrifugal pump with a streamlined pump cover. Background Technology

[0002] In centrifugal pump design, particularly in core components such as impellers, blades, and pump covers, streamlined structures effectively enhance the pump's overall performance. For example, they reduce friction and impact losses within the flow channel, promoting smooth liquid flow and efficiently converting kinetic energy into static pressure energy. Secondly, they increase the inlet flow area, reduce inlet velocity, increase inlet pressure, and lower the required net positive suction head (NPSH). Thirdly, they optimize flow, avoiding vortices and flow separation, and reducing flow pulsation. Fourthly, they enable the pump to maintain high efficiency under various flow conditions, resulting in a wider high-efficiency range. In summary, streamlined structures, by optimizing the liquid flow path, are a core technological means for centrifugal pumps to achieve efficient, stable, and reliable operation. Although the initial manufacturing cost may be slightly higher, the long-term energy savings and reduced maintenance costs make centrifugal pumps with good streamlined designs a preferred choice in many industrial and application scenarios. Therefore, rationally optimizing the design of structures such as the pump cover of multi-stage centrifugal pumps, such as obtaining a high-pressure multi-stage centrifugal pump with a streamlined pump cover, to improve the overall efficiency of centrifugal pumps is particularly important.

[0003] Existing technology CN103161750A discloses a sand removal pump that improves the material formulation of the impeller and pump cover, as well as the blade profile of the impeller, thereby increasing the wear resistance of the pump cover and reducing the scouring effect of the medium exiting the impeller on the pump, thus increasing the service life of the pump. The improved material has a significantly increased hardness, which in turn increases the wear resistance of the parts. Tests show that the material properties of this invention are far superior to those of existing sand removal pumps, with HRC≥55 and HBW≥600. The shape of the flow channel and the blade shape are designed to reduce the impact of particles on the flow channel wall and blades, thereby reducing wear on the pump cover. The pump blades are optimized using two-phase flow theory to improve the trajectory of the pumped medium and reduce the collision and wear of the medium on the pump wall. In other words, the design of this invention effectively solves the problems of easy wear, low efficiency, and high energy consumption in existing sand removal pumps.

[0004] The aforementioned prior art relates to the application of centrifugal pumps. However, the above structure has design limitations, and in the actual application of centrifugal pumps, there are still problems such as low efficiency and energy consumption, high cavitation, unstable vibration and noise, and narrow high-efficiency operating range. Therefore, in order to address these problems, the inventors propose a high-pressure multistage centrifugal pump with a streamlined pump cover. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a high-pressure multistage centrifugal pump with a streamlined pump cover.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A high-pressure multistage centrifugal pump with a streamlined pump cover includes a pump shaft, inlet guide vanes, inlet pump cover, impeller, first guide vanes, second guide vanes, intermediate casing, outlet baffle, pressure ring, outlet pump cover, intermediate baffle, guide cone, coupling, and sealing body. The inlet pump cover, intermediate casing, and outlet pump cover are sequentially connected in series on the outside of the pump shaft to form the pump body. The guide cone is located on the inlet side of the pump shaft, and the coupling is located on the other side of the pump shaft. The impeller, intermediate baffle, outlet baffle, pressure ring, and sealing body are arranged in the middle of the pump shaft. The intermediate baffle connects multiple... The impeller is divided into multiple stages; the outlet baffle, the booster ring, and the outlet pump cover form a cavity; the feature is that: the inlet guide vane is installed on the inner inlet wall of the inlet pump cover, and there is a gap between it and the guide cone; the two opposite sides of the intermediate baffle are respectively provided with the first guide vane and the second guide vane; the booster ring is connected to the outlet side of the outlet baffle, and a gradually narrowing flow channel with multiple booster blades is formed between it and the outlet baffle; the inner inlet wall of the inlet pump cover is provided with a double-hump streamlined structure, and the inner wall of the outlet pump cover is provided with a composite streamlined structure.

[0008] Furthermore, the outline of the double-hump streamlined structure includes points A, B, C, D, E, F, and G arranged sequentially from the inlet side to the outlet side of the inlet pump cover. Among them, curves AB, CD, DE, EF, and GH are line segment structures, while curves BC and FG form the hump section, which is a curved curve.

[0009] Furthermore, the slopes of curves AB, CD, DE, EF, and GH are k1, k2, k3, k4, and k5, respectively, where k1 = k4 and k2 = k5.

[0010] Furthermore, 0 < k1 + k2 ≤ 2.

[0011] Furthermore, points B, C, F, and G are on the same straight line, so k3 = 0.

[0012] Furthermore, curves BC and FG are part of a hyperbola, and the minimum distance between curve BC and the pump shaft is H1, and the minimum distance between curve FG and the pump shaft is H2, where H1 > H2.

[0013] Furthermore, the axial lengths of curves BC and FG are L1 and L2, respectively, where L1 > L2.

[0014] Furthermore, the inlet guide vane is installed on the side of curve DE, the axial length of curve DE is L, and the axial length of the inlet guide vane is L3, where L > 1.2L3.

[0015] Furthermore, the outline of the composite streamlined structure includes points J, K, and L arranged sequentially from the radial inner side to the radial outer side of the outlet pump cover, where curve JK is a line segment structure and curve KL is a curved curve structure.

[0016] Furthermore, curve KL is part of the golden spiral.

[0017] Furthermore, curve JK is tangent to curve KL at point K.

[0018] Furthermore, the outlet baffle is provided with multiple rings of drainage holes with a gradually narrowing cross-section and evenly distributed in annular shape along the axial direction, wherein the diameter of the drainage holes in each ring is different.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. In this invention, the outlet baffle, the booster ring, and the outlet pump cover form an oral cavity; the inlet guide vane is installed on the inlet inner wall of the inlet pump cover, spaced apart from the guide cone; the two opposite sides of the intermediate baffle are respectively provided with a first guide vane and a second guide vane; the booster ring is connected to the outlet side of the outlet baffle, and a gradually narrowing flow channel with multiple booster blades evenly distributed is formed between it and the outlet baffle; the inlet inner wall of the inlet pump cover is provided with a double-hump streamlined structure, and the inner wall of the outlet pump cover is provided with a composite streamlined structure; the optimization of the inlet pump cover, outlet pump cover, and outlet structure effectively improves efficiency and reduces energy consumption, improves cavitation performance, achieves stable operation and low vibration and noise, and widens the high-efficiency operating range.

[0021] 2. The outline of the double-hump streamlined structure in this invention includes points A, B, C, D, E, F, and G sequentially arranged from the inlet side of the inlet pump cover to the outlet side. Curves AB, CD, DE, EF, and GH are line segments, while curves BC and FG form the hump, which are curved curves. The slopes of curves AB, CD, DE, EF, and GH are k1, k2, k3, k4, and k5, respectively, where k1 = k4, k2 = k5, and 0 < k1 + k2 ≤ 2. Points B, C, F, and G are on the same straight line, and k3 = 0. Curves BC, CD, DE, EF, and GH form the hump, which is a curved curve. Line FG is part of a hyperbola, and the minimum distance between curve BC and the pump shaft is H1, and the minimum distance between curve FG and the pump shaft is H2, where H1 > H2; the axial lengths of curve BC and curve FG are L1 and L2, respectively, where L1 > L2; the inlet guide vane is installed on the side of curve DE, the axial length of curve DE is L, and the axial length of the inlet guide vane is L3, where L > 1.2L3; the above-mentioned double-hump streamline enables the pump to operate stably under more demanding suction conditions, reduces cavitation damage to the impeller, increases the inlet flow area, reduces the inlet velocity, and increases the inlet pressure, thereby reducing the required net positive suction head (NPSH) and improving cavitation performance.

[0022] 3. The contour lines of the composite streamlined structure in this invention include points J, K, and L, which are sequentially arranged from the radially inner side to the radially outer side of the outlet pump cover. Curve JK is a line segment structure, and curve KL is a curved curve structure. Curve KL is a part of the golden spiral. Curve JK and curve KL are tangent at point K. The above structure optimizes the outlet flow, avoids vortices and flow separation, reduces liquid flow pulses, improves operational reliability, extends the life of mechanical seals and bearings, and improves the working environment, thereby achieving stable operation and low vibration and noise.

[0023] 4. In this invention, the outlet baffle is provided with multiple rings of drainage holes with a gradually narrowing cross section and evenly distributed in annular shape. The diameter of the drainage holes in each ring is different, which is very beneficial for pumps whose flow rate may change in actual working conditions. This allows the pump to maintain a high frequency under different flow conditions, with a wider high-efficiency range and a broader high-efficiency operating range. Attached Figure Description

[0024] 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. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the multi-stage centrifugal pump of the present invention;

[0026] Figure 2 This is an enlarged schematic diagram of the double-hump streamlined structure of the present invention;

[0027] Figure 3 This is an enlarged schematic diagram of the composite streamlined structure of the present invention.

[0028] The reference numerals in the above figures are as follows: 1. Pump shaft; 2. Inlet guide vane; 3. Inlet pump cover; 4. Impeller; 5. First guide vane; 6. Second guide vane; 7. Intermediate casing; 8. Outlet baffle; 9. Pressure boosting ring; 10. Pressure boosting blade; 11. Outlet pump cover; 12. Intermediate baffle; 13. Guide cone; 14. Coupling; 15. Double-hump streamlined structure; 16. Drain hole; 17. Composite streamlined structure; 18. Sealing body; 19. The slopes of curves AB, CD, DE, EF, and GH are k1, k2, k3, k4, and k5, respectively; the minimum distance H1 between curve BC and pump shaft 1; the minimum distance H2 between curve FG and pump shaft 1; the axial lengths L1 and L2 of curves BC and FG, respectively; the axial length L of curve DE; and the axial length L3 of inlet guide vane 2. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The present invention will now be described in further detail with reference to the accompanying drawings.

[0031] like Figure 1-3As shown, a high-pressure multistage centrifugal pump with a streamlined pump cover includes a pump shaft 1, an inlet guide vane 2, an inlet pump cover 3, an impeller 4, a first guide vane 5, a second guide vane 6, an intermediate shell 7, an outlet baffle 8, a pressure ring 9, an outlet pump cover 11, an intermediate baffle 12, a guide cone 13, a coupling 14, and a sealing body 18. The inlet pump cover 3, the intermediate shell 7, and the outlet pump cover 11 are sequentially connected in series on the outside of the pump shaft 1 to form the pump body. The guide cone 13 is located on the inlet side of the pump shaft 1, and the coupling 14 is located on the other side of the pump shaft 1. The impeller 4, the intermediate baffle 12, the outlet baffle 8, the pressure ring 9, and the sealing body 18 are arranged in the middle of the pump shaft 1. The intermediate partition 12 divides multiple impellers 4 into multi-stage impellers; the outlet partition 8, the booster ring 9, and the outlet pump cover 11 form a cavity; characterized in that: the inlet guide vane 2 is installed on the inlet inner wall of the inlet pump cover 3, and is spaced apart from the guide cone 13; the two opposite sides of the intermediate partition 12 are respectively provided with the first guide vane 5 and the second guide vane 6; the booster ring 9 is connected to the outlet side of the outlet partition 8, and a gradually narrowing flow channel with multiple booster blades 10 evenly distributed is formed between it and the outlet partition 8; the inlet inner wall of the inlet pump cover 3 is provided with a double-hump streamlined structure 15, and the inner wall of the outlet pump cover 11 is provided with a composite streamlined structure 17.

[0032] Furthermore, the outline of the double-hump streamlined structure 15 includes points A, B, C, D, E, F, and G arranged sequentially from the inlet side to the outlet side of the inlet pump cover 3. Among them, curves AB, CD, DE, EF, and GH are line segment structures, and curves BC and FG form the hump section as curved curves.

[0033] Furthermore, the slopes of curves AB, CD, DE, EF, and GH are k1, k2, k3, k4, and k5, respectively, where k1 = k4 and k2 = k5.

[0034] Furthermore, 0 < k1 + k2 ≤ 2.

[0035] Furthermore, points B, C, F, and G are on the same straight line, so k3 = 0.

[0036] Furthermore, curves BC and FG are part of a hyperbola, and the minimum distance between curve BC and pump shaft 1 is H1, and the minimum distance between curve FG and pump shaft 1 is H2, where H1 > H2.

[0037] Furthermore, the axial lengths of curves BC and FG are L1 and L2, respectively, where L1 > L2.

[0038] Furthermore, the inlet guide vane 2 is installed on the side of the curve DE, the axial length of the curve DE is L, and the axial length of the inlet guide vane 2 is L3, where L > 1.2L3.

[0039] Furthermore, the outline of the composite streamlined structure 17 includes points J, K, and L arranged sequentially from the radial inner side to the radial outer side of the outlet pump cover 11, wherein curve JK is a line segment structure and curve KL is a curved curve structure.

[0040] Furthermore, curve KL is part of the golden spiral.

[0041] Furthermore, curve JK is tangent to curve KL at point K.

[0042] Furthermore, the outlet baffle 8 is provided with multiple rings of drainage holes 16 with a gradually narrowing cross section and evenly distributed in annular shape, wherein the diameter of the drainage holes in each ring is different.

[0043] In this invention, the outlet baffle, the booster ring, and the outlet pump cover form an oral cavity; the inlet guide vane is installed on the inner inlet wall of the inlet pump cover, spaced apart from the guide cone; the two opposite sides of the intermediate baffle are respectively provided with a first guide vane and a second guide vane; the booster ring is connected to the outlet side of the outlet baffle, forming a tapered flow channel with multiple booster blades evenly distributed between it and the outlet baffle; the inner inlet wall of the inlet pump cover is provided with a double-hump streamlined structure, and the inner wall of the outlet pump cover is provided with a composite streamlined structure; the optimization of the inlet pump cover, outlet pump cover, and outlet structure effectively improves efficiency and reduces energy consumption, improves cavitation performance, achieves stable operation and low vibration and noise, and widens the high-efficiency operating range.

[0044] In this invention, the outline of the double-hump streamlined structure includes points A, B, C, D, E, F, and G sequentially arranged from the inlet side of the inlet pump cover to the outlet side. Curves AB, CD, DE, EF, and GH are line segments, while curves BC and FG form the hump, which are curved curves. The slopes of curves AB, CD, DE, EF, and GH are k1, k2, k3, k4, and k5, respectively, where k1 = k4, k2 = k5, 0 < k1 + k2 ≤ 2, points B, C, F, and G are on the same straight line, and k3 = 0. Curves BC and FG form the hump, which is a curved curve. FG is part of a hyperbola, and the minimum distance between curve BC and the pump shaft is H1, and the minimum distance between curve FG and the pump shaft is H2, where H1 > H2; the axial lengths of curve BC and curve FG are L1 and L2, respectively, where L1 > L2; the inlet guide vane is installed on the side of curve DE, the axial length of curve DE is L, and the axial length of the inlet guide vane is L3, where L > 1.2L3; the above-mentioned double-hump streamline enables the pump to operate stably under more demanding suction conditions, reduces cavitation damage to the impeller, increases the inlet flow area, reduces the inlet velocity, and increases the inlet pressure, thereby reducing the required net positive suction head (NPSH) and improving cavitation performance.

[0045] The contour lines of the composite streamlined structure in this invention include points J, K, and L, which are sequentially arranged from the radially inner side to the radially outer side of the outlet pump cover. Curve JK is a line segment structure, and curve KL is a curved curve structure. Curve KL is a part of the golden spiral. Curves JK and KL are tangent at point K. The above structure optimizes the outlet flow, avoids vortices and flow separation, reduces liquid flow pulses, improves operational reliability, extends the life of mechanical seals and bearings, and improves the working environment, thereby achieving stable operation and low vibration and noise.

[0046] In this invention, the outlet baffle is provided with multiple rings of drainage holes with a gradually narrowing cross section and evenly distributed in annular shape. The diameter of the drainage holes in each ring is different, which is very beneficial for pumps whose flow rate may change in actual working conditions. This allows the pump to maintain a high frequency under different flow conditions, with a wider high-efficiency range and a broader high-efficiency operating range.

[0047] The above embodiments are illustrative of the present invention and not intended to limit the invention. It is understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-pressure multistage centrifugal pump with a streamlined pump cover, comprising a pump shaft (1), an inlet guide vane (2), an inlet pump cover (3), an impeller (4), a first guide vane (5), a second guide vane (6), an intermediate casing (7), an outlet baffle (8), a pressure ring (9), an outlet pump cover (11), an intermediate baffle (12), a guide cone (13), a coupling (14), and a sealing body (18); the inlet pump cover (3), the intermediate casing (7), and the outlet pump cover (11) are arranged sequentially. A pump body is formed by connecting the pump shaft (1) in series on the outside of the pump shaft (1). A guide cone (13) is located on the inlet side of the pump shaft (1), and a coupling (14) is located on the other side of the pump shaft (1). Impellers (4), intermediate partitions (12), outlet partitions (8), pressure rings (9), and sealing bodies (18) are arranged in the middle of the pump shaft (1). The intermediate partitions (12) divide multiple impellers (4) into multiple stages of impellers. The outlet partitions (8), pressure rings (9), and outlet pump covers (11) form an oral cavity. The pump body is characterized by: The inlet guide vane (2) is installed on the inner wall of the inlet of the inlet pump cover (3) and is spaced apart from the guide cone (13); the two opposite sides of the middle partition plate (12) are respectively provided with the first guide vane (5) and the second guide vane (6); the pressure ring (9) is connected to the outlet side of the outlet partition plate (8) and forms a gradually narrowing flow channel with multiple pressure boosting blades (10) evenly distributed between it and the outlet partition plate (8); the inner wall of the inlet of the inlet pump cover (3) is provided with a double-hump streamlined structure (15) and the inner wall of the outlet pump cover (11) is provided with a composite streamlined structure (17).

2. A high-pressure multistage centrifugal pump with a streamlined pump cover as described in claim 1, characterized in that, The outline of the double-hump streamlined structure (15) includes points A, B, C, D, E, F and G arranged sequentially from the inlet side to the outlet side of the inlet pump cover (3). Among them, curves AB, CD, DE, EF and GH are line segment structures, and curves BC and FG form the hump part as curved curves.

3. A high-pressure multistage centrifugal pump with a streamlined pump cover as described in claim 2, characterized in that, The slopes of curves AB, CD, DE, EF, and GH are k1, k2, k3, k4, and k5, respectively, where k1 = k4 and k2 = k5.

4. A high-pressure multistage centrifugal pump with a streamlined pump cover as described in claim 3, characterized in that, 0 < k1 + k2 ≤ 2.

5. A high-pressure multistage centrifugal pump with a streamlined pump cover as described in claim 3, characterized in that, Points B, C, F, and G are on the same straight line, and k3 = 0.

6. A high-pressure multistage centrifugal pump with a streamlined pump cover as described in claim 2, characterized in that, Curves BC and FG are part of a hyperbola, and the minimum distance between curve BC and pump shaft (1) is H1, and the minimum distance between curve FG and pump shaft (1) is H2, where H1 > H2.

7. A high-pressure multistage centrifugal pump with a streamlined pump cover as described in claim 2, characterized in that, The axial lengths of curves BC and FG are L1 and L2, respectively, where L1 > L2.

8. A high-pressure multistage centrifugal pump with a streamlined pump cover as described in claim 2, characterized in that, The inlet guide vane (2) is installed on the side of the curve DE. The axial length of the curve DE is L, and the axial length of the inlet guide vane (2) is L3, where L > 1.2L3.

9. A high-pressure multistage centrifugal pump with a streamlined pump cover as described in claim 1, characterized in that, The outline of the composite streamlined structure (17) includes points J, K and L arranged sequentially from the radial inner side to the radial outer side of the outlet pump cover (11), where curve JK is a line segment structure and curve KL is a curved curve structure.

10. A high-pressure multistage centrifugal pump with a streamlined pump cover as described in claim 9, characterized in that, Curve KL is part of the golden spiral.

11. A high-pressure multistage centrifugal pump with a streamlined pump cover as described in claim 10, characterized in that, Curve JK is tangent to curve KL at point K.

12. A high-pressure multistage centrifugal pump with a streamlined pump cover as described in claim 1, characterized in that, The outlet baffle (8) is provided with multiple rings of drainage holes (16) with a gradually narrowing cross section and evenly distributed in annular shape, wherein the diameter of the drainage holes in each ring is different.

Images