A centrifugal pump with improved blade shape to improve cavitation resistance

Abstract

The invention discloses a centrifugal pump based on blade shape improvement to improve anti-cavitation performance, which includes an impeller and a volute, wherein the impeller includes a front cover plate, a rear cover plate, a main blade, a first guide blade, and a second guide blade, wherein a plurality of first guide blades and a second guide blade are installed on the inner side surface of the rear cover plate and are located upstream of the main blade; the invention is characterized in that: the first guide blade is arranged on a first adjustment ring, the second guide blade is arranged on a second adjustment ring, and the first adjustment ring and / or the second adjustment ring can rotate circumferentially to adjust the circumferential position and liquid flow angle of the first guide blade relative to the second guide blade, and / or the circumferential position and liquid flow angle of the second guide blade relative to the main blade. The invention can adjust the pressure difference between the pressure surface and the negative pressure surface of the main blade, and adjust the flow state of the liquid flow between the impeller flow channels, thereby effectively improving the anti-cavitation performance of the centrifugal pump, reducing the hydraulic loss of the centrifugal pump, and improving the hydraulic efficiency of the centrifugal pump.

Description

Technical Field

[0001] The invention relates to the technical field of centrifugal pumps, and in particular to a centrifugal pump with improved blade shape to enhance anti-cavitation performance. Background Art

[0002] like Figure 1 As shown, the existing centrifugal pump includes a volute, an impeller, and a motor. The impeller is rotatably installed in the volute. A rotating shaft is installed in the hub of the impeller. The rotating shaft is connected to the motor by transmission. The impeller includes a front cover plate, a rear cover plate, a main blade, a hub, a first guide blade, and a second guide blade. A plurality of main blades are evenly distributed along the circumference and connected between the front cover plate and the rear cover plate. A hub is provided at the center of the rear cover plate. A plurality of first guide blades are evenly distributed along the circumference. A plurality of second guide blades are evenly distributed along the circumference. A plurality of first guide blades and second guide blades are installed on the inner side of the rear cover plate and are located radially inwardly upstream of the main blades. However, the existing centrifugal pumps still have the problems that the relative circumferential position between the guide blades and the main blades, the liquid flow angle cannot be adjusted or the adjustment effect is poor, the anti-cavitation performance is poor, and the hydraulic efficiency needs to be further improved. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a centrifugal pump based on blade shape improvement to improve anti-cavitation performance, which can adjust the relative circumferential position and liquid flow angle between the first guide vane, the second guide vane and the main blade, and can adjust the axial height position of the first guide vane and the second guide vane, so as to adjust the pressure difference between the pressure surface and the negative pressure surface of the main blade, and adjust the liquid flow state between the impeller flow channels, so as to effectively improve the anti-cavitation performance of the centrifugal pump, reduce the hydraulic loss of the centrifugal pump, and improve the hydraulic efficiency of the centrifugal pump.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A centrifugal pump based on blade shape improvement to improve cavitation resistance, comprising a volute, an impeller, and a motor, wherein the impeller is rotatably mounted in the volute, a rotating shaft is mounted in the central hub of the impeller, and the rotating shaft is transmission-connected to the motor, the impeller comprises a front cover plate, a rear cover plate, main blades, a central hub, a first guide blade, and a second guide blade, a plurality of main blades are evenly distributed along the circumferential direction and connected between the front cover plate and the rear cover plate, a central hub is arranged at the center of the rear cover plate, a plurality of first guide blades are evenly distributed along the circumferential direction, a plurality of second guide blades are evenly distributed along the circumferential direction, a plurality of first guide blades and a second guide blade are mounted on the inner side surface of the rear cover plate and are located radially inwardly upstream of the main blade; characterized in that: the first guide blade is arranged on a first adjustment ring, the second guide blade is arranged on a second adjustment ring, and the first adjustment ring and / or the second adjustment ring can rotate along the circumferential direction to adjust the circumferential position and liquid flow angle of the first guide blade relative to the second guide blade, and / or the circumferential position and liquid flow angle of the second guide blade relative to the main blade.

[0006] Furthermore, a first annular boss and a second annular boss are provided on the inner side surface of the rear cover plate, the inner circumferential surface of the first annular boss is provided with a first internal thread, the outer circumferential surface of the first adjustment ring is provided with a first external thread, the first adjustment ring is threadedly connected to the first annular boss so as to be able to rotate circumferentially, thereby adjusting the circumferential position and liquid flow angle of the first guide blade relative to the second guide blade; the inner circumferential surface of the second annular boss is provided with a second internal thread, the outer circumferential surface of the second adjustment ring is provided with a second external thread, the second adjustment ring is threadedly connected to the second annular boss so as to be able to rotate circumferentially, thereby adjusting the circumferential position and liquid flow angle of the second guide blade relative to the main blade.

[0007] Furthermore, a first annular mounting groove is provided on the inner side surface of the rear cover plate and located radially inward of the first annular boss, and the first adjustment ring is rotatably installed in the first annular mounting groove; a second annular mounting groove is provided on the inner side surface of the rear cover plate and located between the first annular boss and the second annular boss, and the second adjustment ring is rotatably installed in the second annular mounting groove.

[0008] Furthermore, the first adjusting ring is provided with one or more first mounting holes, in which a first set screw / bolt is installed for fastening the adjusting ring; the second adjusting ring is provided with one or more second mounting holes, in which a second set screw / bolt is installed for fastening the adjusting ring.

[0009] Furthermore, one side of the main blade is plug-connected to the front cover plate via a plurality of positioning protrusions and slots, and is fastened via a plurality of threaded connectors.

[0010] Furthermore, the top of the first guide blade has a first top edge, and the top of the second guide blade has a second top edge. The first top edge and the second top edge can be adjusted to be approximately located on the same inclined line through the first adjustment ring and the second adjustment ring, and the angle a between the inclined line and the inner side surface of the first adjustment ring or the second adjustment ring is 10-30°.

[0011] Furthermore, under one adjustment condition, the inner side surface of the first adjustment ring is flush with the inner side surface of the second adjustment ring, the maximum axial height of the first guide vane is less than the minimum axial height of the second guide vane, the second guide vane has a maximum axial height H1, and the leading edge of the main blade has an axial height H2, H1=(0.25-0.5)H2; at this time, the inner side surface of the first adjustment ring, the inner side surface of the second adjustment ring, the inner side surface of the first annular boss, and the inner side surface of the second annular boss are flush.

[0012] Furthermore, the first guide blade, the second guide blade and the main blade are all arc-shaped blades. From the radial inside to the radial outside, the first guide blade, the second guide blade and the main blade are arranged at intervals in sequence. The first guide blade has the same bending direction as the main blade, and the second guide blade has an opposite bending direction to the main blade.

[0013] Furthermore, the number of blades of the second guide blades is twice the number of blades of the main blades, the number of blades of the first guide blades is 2-4 times the number of blades of the main blades, and the number of blades of the first guide blades is 1-2 times the number of blades of the second guide blades.

[0014] The centrifugal pump is applicable to various flow conditions and can be a fire pump. The impeller is a centrifugal impeller.

[0015] A centrifugal pump based on blade shape improvement to improve cavitation resistance of the present invention has the following beneficial technical effects:

[0016] (1) The present invention arranges the first guide vane and the second guide vane to be adjustable. Specifically, the adjustable mechanism includes a first adjusting ring, a second adjusting ring, a thread pair, and an annular mounting groove. The relative circumferential position and the liquid flow angle between the first guide vane, the second guide vane, and the main blade can be adjusted, and the axial height position of the first guide vane and the second guide vane can be adjusted. Thus, the pressure difference between the pressure surface and the negative pressure surface of the main blade can be adjusted, and the liquid flow state between the impeller flow channels can be adjusted. This can effectively improve the anti-cavitation performance of the centrifugal pump, reduce the hydraulic loss of the centrifugal pump, and improve the hydraulic efficiency of the centrifugal pump.

[0017] (2) The present invention optimizes the design of specific parameters of the first guide vane and the second guide vane, specifically the design of the angle a, the axial heights H1 and H2, the blade bending direction, and the number of blades, so that the relative circumferential positions and the liquid flow angles between the first guide vane, the second guide vane, and the main blade can be adjusted more efficiently, and the axial height positions of the first guide vane and the second guide vane can be adjusted, so that the pressure difference between the pressure surface and the negative pressure surface of the main blade can be better adjusted, and the flow state of the liquid in the impeller flow channel can be adjusted, so that the anti-cavitation performance of the centrifugal pump can be better improved, the hydraulic loss of the centrifugal pump can be reduced, and the hydraulic efficiency of the centrifugal pump can be improved.

[0018] (3) The adjusting ring and blade installation method provided in the present invention facilitates the installation and disassembly of the adjusting ring and the maintenance of the impeller. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the impeller structure of a centrifugal pump in the prior art;

[0020] Figure 2 The schematic diagram of the impeller structure of the centrifugal pump based on the improvement of the blade shape to improve the anti-cavitation performance of the present invention;

[0021] Figure 3 It is a schematic diagram of a partially enlarged structure of an impeller of a centrifugal pump based on the improvement of the blade shape to improve the anti-cavitation performance of the present invention;

[0022] Figure 4 The diagram is a top view of the structure of the impeller of a centrifugal pump based on the improvement of the blade shape to improve the anti-cavitation performance of the present invention.

[0023] In the figure: front cover plate 1, rear cover plate 2, main blade 3, central hub 4, first guide blade 5, first adjustment ring 6, second guide blade 7, second adjustment ring 8, first annular boss 9, second annular boss 10, first mounting hole 11, second mounting hole 12, top edge 13, first annular mounting groove 15, second annular mounting groove 14. DETAILED DESCRIPTION

[0024] In order to make the technical solution and advantages of the present invention clearer, the technical solution of the present invention will be further described in detail in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present invention, which are only used to explain the present invention, not to limit the present invention. It should be noted that, for the convenience of description, only the parts / structures related to the present invention are shown in the accompanying drawings, and other related parts can refer to the general design. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other to obtain new embodiments.

[0025] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In addition, unless otherwise defined, the technical terms or scientific terms used in the description of the present invention should be the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0026] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0027] like Figure 2-4 As shown, a centrifugal pump based on blade shape improvement to improve cavitation resistance performance includes a volute, an impeller, and a motor. The impeller is rotatably installed in the volute, a rotating shaft is installed in the central hub of the impeller, and the rotating shaft is connected to the motor by transmission. The impeller includes a front cover plate 1, a rear cover plate 2, main blades 3, a central hub 4, a first guide blade 5, and a second guide blade 7. A plurality of main blades 3 are evenly distributed along the circumference and connected between the front cover plate 1 and the rear cover plate 2. A central hub 4 is provided at the center of the rear cover plate 2. A plurality of first guide blades 5 are evenly distributed along the circumference. A plurality of second guide blades 7 are evenly distributed along the circumference. The two guide blades 7 are evenly distributed along the circumferential direction, and a plurality of first guide blades 5 and second guide blades 7 are installed on the inner side surface of the rear cover plate 2 and are located radially inner and upstream of the main blade 3; it is characterized in that: the first guide blade 5 is arranged on the first adjustment ring 6, and the second guide blade 7 is arranged on the second adjustment ring 8, and the first adjustment ring 6 and / or the second adjustment ring 8 can rotate along the circumferential direction to adjust the circumferential position and liquid flow angle of the first guide blade 5 relative to the second guide blade 7, and / or the circumferential position and liquid flow angle of the second guide blade 7 relative to the main blade 3.

[0028] Furthermore, a first annular boss 9 and a second annular boss 10 are provided on the inner side surface of the rear cover plate 2, the inner circumferential surface of the first annular boss 9 is provided with a first internal thread, the outer circumferential surface of the first adjustment ring 6 is provided with a first external thread, the first adjustment ring 6 is threadedly connected to the first annular boss 9 so as to be able to rotate circumferentially, thereby adjusting the circumferential position and liquid flow angle of the first guide blade 5 relative to the second guide blade 7; the inner circumferential surface of the second annular boss 10 is provided with a second internal thread, the outer circumferential surface of the second adjustment ring 8 is provided with a second external thread, the second adjustment ring 8 is threadedly connected to the second annular boss 10 so as to be able to rotate circumferentially, thereby adjusting the circumferential position and liquid flow angle of the second guide blade 7 relative to the main blade 3.

[0029] A first annular mounting groove 15 is provided on the inner side surface of the rear cover plate 2 and located radially inwardly of the first annular boss 9, and the first adjustment ring 6 is rotatably installed in the first annular mounting groove 15. A second annular mounting groove 14 is provided on the inner side surface of the rear cover plate 2 and located between the first annular boss 9 and the second annular boss 10, and the second adjustment ring 8 is rotatably installed in the second annular mounting groove 14.

[0030] The present invention discloses a centrifugal pump with improved anti-cavitation performance based on blade shape improvement. The first guide vane 5 and the second guide vane 7 are set to be adjustable. Specifically, the adjustable mechanism includes a first adjusting ring 6, a second adjusting ring 8, a threaded pair, and an annular mounting groove. The relative circumferential position and the liquid flow angle between the first guide vane 5, the second guide vane 7, and the main blade 3 can be adjusted, and the axial height position of the first guide vane 5 and the second guide vane 7 can be adjusted, so that the pressure difference between the pressure surface and the negative pressure surface of the main blade 3 can be adjusted, and the liquid flow state between the impeller flow channels can be adjusted, so that the anti-cavitation performance of the centrifugal pump can be effectively improved, the hydraulic loss of the centrifugal pump can be reduced, and the hydraulic efficiency of the centrifugal pump can be improved.

[0031] In one embodiment, one or more first mounting holes 11 are formed on the first adjusting ring 6, and a first set screw / bolt is installed in the first mounting hole 11 for fastening the adjusting ring; one or more second mounting holes 12 are formed on the second adjusting ring 8, and a second set screw / bolt is installed in the second mounting hole 12 for fastening the adjusting ring.

[0032] In one embodiment, one side of the main blade 3 is connected to the front cover plate 1 by multiple positioning protrusions and slots (the connection method by multiple positioning protrusions and slots is a prior art), and is fastened by multiple threaded connectors. The present invention is arranged in this installation method to facilitate the installation and removal of the adjustment ring and the maintenance of the impeller.

[0033] Furthermore, the top of the first guide blade 5 has a first top edge, and the top of the second guide blade 7 has a second top edge 13. The first top edge and the second top edge 13 can be adjusted to be approximately located on the same inclined line through the first adjusting ring 6 and the second adjusting ring 8. The angle a between the inclined line and the inner side surface of the first adjusting ring 6 or the second adjusting ring 8 is 15-25°, preferably 20°.

[0034] Under one adjustment condition, the inner side surface of the first adjustment ring 6 is flush with the inner side surface of the second adjustment ring 8, the maximum axial height of the first guide vane 5 is less than the minimum axial height of the second guide vane 7, the second guide vane 7 has a maximum axial height H1, and the leading edge of the main blade 3 has an axial height H2, H1=(0.3-0.5)H2, preferably 0.4; at this time, the inner side surface of the first adjustment ring 6, the inner side surface of the second adjustment ring 8, the inner side surface of the first annular boss 9, and the inner side surface of the second annular boss 10 are flush.

[0035] The present invention optimizes the specific parameters of the first guide vane 5 and the second guide vane 7, specifically the design of the angle a, the axial height H1, and the H2, so that the relative circumferential position and the liquid flow angle between the first guide vane 5, the second guide vane 7, and the main blade 3 can be adjusted more efficiently, and the axial height position of the first guide vane 5 and the second guide vane 7 can be adjusted, so as to better adjust the pressure difference between the pressure surface and the negative pressure surface of the main blade 3, and adjust the flow state of the liquid between the impeller flow channels, so as to better improve the anti-cavitation performance of the centrifugal pump, reduce the hydraulic loss of the centrifugal pump, and improve the hydraulic efficiency of the centrifugal pump.

[0036] Furthermore, the first guide blade 5, the second guide blade 7, and the main blade 3 are all arc-shaped blades. From the radial inside to the radial outside, the first guide blade 5, the second guide blade 7, and the main blade 3 are arranged at intervals in sequence. The first guide blade 5 has the same bending direction as the main blade 3, and the second guide blade 7 has an opposite bending direction to the main blade 3.

[0037] The number of the second guide blades 7 is twice the number of the main blades 3 , the number of the first guide blades 5 is 2-4 times the number of the main blades 3 , and the number of the first guide blades 5 is 1-2 times the number of the second guide blades 7 , preferably 1 time.

[0038] The present invention optimizes the specific parameters of the first guide blade 5 and the second guide blade 7, specifically the design of the blade bending direction and the number of blades, so that the relative circumferential position and the liquid flow angle between the first guide blade 5, the second guide blade 7 and the main blade 3 can be adjusted more efficiently, and the axial height position of the first guide blade 5 and the second guide blade 7 can be adjusted, so as to better adjust the pressure difference between the pressure surface and the negative pressure surface of the main blade 3, and adjust the liquid flow state between the impeller flow channels, so as to better improve the anti-cavitation performance of the centrifugal pump, reduce the hydraulic loss of the centrifugal pump, and improve the hydraulic efficiency of the centrifugal pump.

[0039] The centrifugal pump is applicable to various flow conditions and can be a fire pump. The impeller is a centrifugal impeller.

[0040] A centrifugal pump based on blade shape improvement to improve cavitation resistance of the present invention has the following beneficial technical effects:

[0041] (1) The present invention arranges the first guide vane and the second guide vane to be adjustable. Specifically, the adjustable mechanism includes a first adjusting ring, a second adjusting ring, a thread pair, and an annular mounting groove. The relative circumferential position and the liquid flow angle between the first guide vane, the second guide vane, and the main blade can be adjusted, and the axial height position of the first guide vane and the second guide vane can be adjusted. Thus, the pressure difference between the pressure surface and the negative pressure surface of the main blade can be adjusted, and the liquid flow state between the impeller flow channels can be adjusted. This can effectively improve the anti-cavitation performance of the centrifugal pump, reduce the hydraulic loss of the centrifugal pump, and improve the hydraulic efficiency of the centrifugal pump.

[0042] (2) The present invention optimizes the design of specific parameters of the first guide vane and the second guide vane, specifically the design of the angle a, the axial heights H1 and H2, the blade bending direction, and the number of blades, so that the relative circumferential positions and the liquid flow angles between the first guide vane, the second guide vane, and the main blade can be adjusted more efficiently, and the axial height positions of the first guide vane and the second guide vane can be adjusted, so that the pressure difference between the pressure surface and the negative pressure surface of the main blade can be better adjusted, and the flow state of the liquid in the impeller flow channel can be adjusted, so that the anti-cavitation performance of the centrifugal pump can be better improved, the hydraulic loss of the centrifugal pump can be reduced, and the hydraulic efficiency of the centrifugal pump can be improved.

[0043] (3) The adjusting ring and blade installation method provided in the present invention facilitates the installation and disassembly of the adjusting ring and the maintenance of the impeller.

[0044] The above-mentioned implementation modes are for explanation of the present invention rather than limitation of the present invention. It can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A centrifugal pump with improved blade shape to improve anti-cavitation performance, comprising a volute, an impeller and a motor, wherein the impeller is rotatably mounted in the volute, a rotating shaft is mounted in a central hub of the impeller, and the rotating shaft is drivingly connected to the motor, the impeller comprising a front cover plate (1), a rear cover plate (2), main blades (3), a central hub (4), a first guide blade (5) and a second guide blade (7), a plurality of main blades are evenly distributed along the circumferential direction and connected between the front cover plate and the rear cover plate, a central hub is arranged at the center of the rear cover plate, a plurality of first guide blades are evenly distributed along the circumferential direction, a plurality of second guide blades are evenly distributed along the circumferential direction, and a plurality of first guide blades and a second guide blade are mounted on the inner side surface of the rear cover plate and are located radially inwardly upstream of the main blades; Features: The first guide blade (5) is arranged on the first adjustment ring (6), and the second guide blade (7) is arranged on the second adjustment ring (8). The first adjustment ring and / or the second adjustment ring can rotate in the circumferential direction to adjust the circumferential position and liquid flow angle of the first guide blade relative to the second guide blade, and / or the circumferential position and liquid flow angle of the second guide blade relative to the main blade; the inner side surface of the rear cover plate (2) is provided with a first annular boss (9) and a second annular boss (10), the inner circumferential surface of the first annular boss is provided with a first internal thread, and the second internal thread is provided with a first internal thread. An adjusting ring (6) is provided with a first external thread on its outer circumferential surface, and the first adjusting ring is threadedly connected to the first annular boss so as to be rotatable in the circumferential direction, thereby adjusting the circumferential position and liquid flow angle of the first guide blade (5) relative to the second guide blade (7); a second internal thread is provided on the inner circumferential surface of the second annular boss, and a second external thread is provided on the outer circumferential surface of the second adjusting ring (8), and the second adjusting ring is threadedly connected to the second annular boss so as to be rotatable in the circumferential direction, thereby adjusting the circumferential position and liquid flow angle of the second guide blade relative to the main blade (3).

2. A centrifugal pump with improved blade shape to improve anti-cavitation performance as claimed in claim 1, characterized in that: A first annular mounting groove (15) is provided on the inner side surface of the rear cover plate (2) and is located radially inward of the first annular boss (9), and the first adjustment ring (6) is rotatably mounted in the first annular mounting groove. A second annular mounting groove (14) is provided on the inner side surface of the rear cover plate and is located between the first annular boss and the second annular boss (10), and the second adjustment ring (8) is rotatably mounted in the second annular mounting groove.

3. A centrifugal pump with improved blade shape to improve anti-cavitation performance as claimed in claim 2, characterized in that: The first adjustment ring (6) is provided with one or more first mounting holes (11), in which a first set screw / bolt is installed for fastening the first adjustment ring; the second adjustment ring (8) is provided with one or more second mounting holes (12), in which a second set screw / bolt is installed for fastening the second adjustment ring.

4. A centrifugal pump with improved blade shape to improve anti-cavitation performance as claimed in claim 3, characterized in that: One side of the main blade (3) is plug-connected to the front cover plate (1) via a plurality of positioning protrusions and slots, and is fastened via a plurality of threaded connectors.

5. A centrifugal pump with improved blade shape to improve anti-cavitation performance as claimed in claim 4, characterized in that: The top of the first guide blade (5) has a first top edge, and the top of the second guide blade (7) has a second top edge (13). The first top edge and the second top edge can be adjusted to be located approximately on the same inclined line through a first adjustment ring (6) and a second adjustment ring (8), and the angle a between the inclined line and the inner side surface of the first adjustment ring or the second adjustment ring is 10-30 degrees.

6. A centrifugal pump with improved blade shape to improve anti-cavitation performance as claimed in claim 5, characterized in that: Under one adjustment condition, the inner side surface of the first adjustment ring (6) is flush with the inner side surface of the second adjustment ring (8), the maximum axial height of the first guide blade (5) is less than the minimum axial height of the second guide blade (7), the second guide blade has a maximum axial height H1, and the leading edge of the main blade (3) has an axial height H2, where H1=(0.25-0.5)H2; at this time, the inner side surface of the first adjustment ring, the inner side surface of the second adjustment ring, the inner side surface of the first annular boss (9), and the inner side surface of the second annular boss (10) are flush.

7. A centrifugal pump with improved blade shape to improve anti-cavitation performance as claimed in claim 4 or 6, characterized in that: The first guide blade (5), the second guide blade (7) and the main blade (3) are all arc-shaped blades, and are arranged in sequence with intervals from the radial inside to the radial outside. The first guide blade and the main blade have the same bending direction, and the second guide blade and the main blade have an opposite bending direction.

8. A centrifugal pump with improved blade shape to improve anti-cavitation performance as claimed in claim 7, characterized in that: The number of blades of the second guide blades (7) is twice the number of blades of the main blades (3), the number of blades of the first guide blades (5) is 2-4 times the number of blades of the main blades, and the number of blades of the first guide blades is 1-2 times the number of blades of the second guide blades.

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