Single-side double-suction impeller structure

Abstract

The single-side double-suction impeller structure comprises a cover plate, a plurality of front face blades arranged on the front face of the cover plate and a plurality of back face blades arranged on the back face of the cover plate, and the molded lines of the front face blades and the molded lines of the back face blades are the same; a plurality of flow distribution channels are formed in the cover plate, the flow distribution channels are arranged around the center of the cover plate in the circumferential direction at intervals, each flow distribution channel is arranged at the inlet of the corresponding front face blade and the inlet of the corresponding back face blade, and each flow distribution channel is arranged between every two adjacent front face blades and between every two adjacent back face blades. Through the arrangement of the single-side double-suction impeller structure, the single-side double-suction function can be achieved through the impeller structure, and the structure is simple and compact on the premise that good cavitation resistance and axial force balance are guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of impeller structures, and in particular to a single-sided double-suction impeller structure. Background Art

[0002] In the field of centrifugal pumps, single-stage single-suction impellers and single-stage double-suction impellers are two common impeller types. The single-stage single-suction impeller has a simple structure, but under large flow conditions, the anti-cavitation performance is poor and the axial force balance is not good. The single-stage double-suction impeller has better flow and structural stability, better anti-cavitation performance, but the suction section structure is more complicated.

[0003] In view of the above-mentioned related technologies, in the fuel supply and hydraulic medium circulation equipment in the fields of aerospace, marine engineering, etc., good cavitation resistance and good axial force balance are the basis, but the requirements of simple and compact structure must be taken into account. For this reason, a single-sided double-suction impeller structure is proposed. Summary of the invention

[0004] In order to achieve a simple and compact structure, the present application provides a single-sided double-suction impeller structure.

[0005] The single-sided double-suction impeller structure provided in this application adopts the following technical solution: A single-sided double-suction impeller structure comprises a cover plate, a plurality of front blades arranged on the front of the cover plate, and a plurality of back blades arranged on the back of the cover plate, wherein the front blades and the back blades have the same profile; The cover plate is provided with a plurality of flow distribution channels, which are arranged circumferentially around the center of the cover plate, each of which is arranged at the inlet of the front blade and the back blade, and each of which is arranged between two adjacent front blades and two adjacent back blades.

[0006] Preferably, a plurality of drainage channels are provided on the cover plate, and the plurality of drainage channels are circumferentially spaced around the center of the cover plate, each of the drainage channels is communicated with each of the flow distribution channels, and a drainage plate is provided in each of the drainage channels.

[0007] Preferably, the guide plate is formed with a guide slope which is inclined toward the flow distribution channel and toward the back blade side.

[0008] Preferably, the drainage channel and the flow distribution channel are both arranged in a fan shape, and the radii of the upper arc line and the lower arc line of the drainage channel and the flow distribution channel are the same.

[0009] Preferably, the distance between the upper arc line of the flow distribution channel and the ends of the front blade and the back blade inlet is 3-5 mm.

[0010] Preferably, the diameter of the circle formed by the upper arc lines of all the diversion channels and the distribution channels is close to the diameter of the water inlet formed by the front blades.

[0011] Preferably, the front flow rate of the single-sided double-suction impeller structure is q1, the back flow rate of the single-sided double-suction impeller structure is q2, and the single-sided double-suction impeller structure is configured with q2=kq1, wherein k is a constant, k=0.2-0.7; The back flow rate of the single-sided double-suction impeller structure is q2=nsv, where n is the number of distribution channels, s is the effective flow area of ​​the distribution channels, and v is the flow velocity of the distribution channels; The effective flow area of ​​the flow distribution channel is s=wd, where w is the width of the flow distribution channel and d is the thickness of the cover plate; The flow velocity v of the distribution channel is (3.14*n*C*R) / 30, wherein n is the number of distribution channels, C is the correction coefficient, C=1-1.3, and R is the centerline radius of the distribution channel.

[0012] Preferably, a front flow channel is formed between adjacent front blades, and a back flow channel is formed between adjacent back blades, and the flow cross-sectional area of ​​the back flow channel is 0.3 to 0.8 times the flow cross-sectional area of ​​the front flow channel.

[0013] Preferably, the cover plate is provided with splitter blades between adjacent back blades, and the inlet position of the splitter blade is located at one third of the back flow passage.

[0014] Preferably, the splitter blades separate the back flow passage into two splitter passages, and the cover plate is provided with at least one connecting hole in the splitter passage.

[0015] In summary, the present application includes at least one of the following beneficial technical effects: The present application adopts the setting of a single-sided double-suction impeller structure, which can realize the function of single-sided double-suction while ensuring good cavitation resistance and axial force balance, and has a simple and compact structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the installation diagram of the single-sided double-suction impeller structure.

[0017] Figure 2 This is a schematic diagram of the first arrangement of the front blades.

[0018] Figure 3 This is a schematic diagram of the arrangement of the back blades.

[0019] Figure 4 It is a structural schematic diagram of the flow distribution channel.

[0020] Figure 5 This is a schematic diagram of the second arrangement of the front blades.

[0021] Figure 6 It is a schematic diagram of the height of the front blade and the back blade.

[0022] Explanation of the reference numerals: 1. Cover plate; 2. Front blade; 3. Back blade; 4. Mounting shaft hole; 5. Distribution channel; 6. Drainage channel; 7. Drainage plate; 8. Diverter blade; 9. Connecting hole. DETAILED DESCRIPTION

[0023] The following is combined with Figure 1-6 This application is described in further detail.

[0024] A single-sided double-suction impeller structure, referring to Figure 1 As shown, when applied to a semi-open impeller structure or a closed impeller structure, the function of single-side double suction can be realized, and at the same time, the blade structure is specifically designed to achieve the effect of completely balancing the axial forces on both sides.

[0025] Specifically, refer to Figure 2 , Figure 3 and Figure 4 As shown, the single-sided double-suction impeller structure includes a cover plate 1, a plurality of front blades 2 arranged on the front side of the cover plate 1, and a plurality of back blades 3 arranged on the back side of the cover plate 1. The middle part of the cover plate 1 is a mounting shaft hole 4. In one embodiment, the mounting shaft hole 4 is a spline hole. In another embodiment, a flat keyway is provided on the mounting shaft hole 4. The impeller can be assembled to the main shaft of the water pump through the mounting shaft hole 4.

[0026] The profile of each front blade 2 and each back blade 3 is the same, a number of front blades 2 are distributed in a spiral shape around the mounting shaft hole 4 in the center of the cover plate 1, a number of back blades 3 are distributed in a spiral shape around the mounting shaft hole 4 in the center of the cover plate 1, one end of all the front blades 2 and all the back blades 3 close to the mounting shaft hole 4 is an inlet, and the other ends of all the front blades 2 and all the back blades 3 are flush with the outer edge of the cover plate 1.

[0027] A plurality of flow distribution channels 5 are provided on the cover plate 1, and the flow distribution channels 5 penetrate the cover plate 1 in the axial direction. The plurality of flow distribution channels 5 are arranged circumferentially at intervals around the center of the cover plate 1, and each flow distribution channel 5 is arranged at the inlet of the front blade 2 and the back blade 3, and each flow distribution channel 5 is arranged between two adjacent front blades 2 and two adjacent back blades 3.

[0028] The cover plate 1 is provided with a plurality of drainage channels 6, which are arranged circumferentially around the center of the cover plate 1, and each drainage channel 6 is connected to each of the distribution channels 5. Figure 2For reference direction, the drainage channel 6 is arranged on the left side of the distribution channel 5, and a drainage plate 7 is arranged in each drainage channel 6. The drainage plate 7 fills the entire drainage channel 6, and the right edge of the drainage plate 7 is connected with the distribution channel 5. The drainage slope inclined toward the distribution channel 5 toward the side of the back blade 3 is formed on the drainage plate 7. As a result, the water body can be guided by the drainage plate 7 in the drainage channel 6 to enter the distribution channel 5, so that a part of the water body enters the back of the cover plate 1 from the front side of the cover plate 1.

[0029] The flow diversion channel 6 and the flow distribution channel 5 are both arranged in a fan shape, and the radius of the upper arc line and the lower arc line of the flow diversion channel 6 and the flow distribution channel 5 are the same. Among them, the distance between the upper arc line of the flow distribution channel 5 and the end of the inlet of the front blade 2 and the back blade 3 is 3-5mm, and preferably, the distance between the upper arc line of the flow distribution channel 5 and the end of the inlet of the front blade 2 and the back blade 3 is 4mm.

[0030] The diameter of the circle formed by the upper arc lines of all drainage channels 6 and distribution channels 5 is close to the diameter of the water inlet formed by the front blades 2. The approaching here means that the diameter of the circle formed by the upper arc lines of all drainage channels 6 and distribution channels 5 is 1-3mm smaller than the diameter of the water inlet formed by the front blades 2, preferably 2mm.

[0031] By setting the distribution channel 5, the front side of the cover plate 1 and the back side of the cover plate 1 can be connected, a part of the water is discharged through the front blades 2, and the other part of the water enters the back side of the cover plate 1 through the distribution channel 5 and is discharged through the back blades 3, thereby realizing a single-side double-suction impeller structure.

[0032] The following is the design of the front flow and back flow of the single-sided double-suction impeller structure.

[0033] The front flow rate of the single-sided double-suction impeller structure is q1, and the back flow rate of the single-sided double-suction impeller structure is q2. The single-sided double-suction impeller structure is configured with q2=kq1, wherein k is a constant, k=0.2~0.7.

[0034] The back flow rate of the single-sided double-suction impeller structure is q2=nsv, wherein n is the number of the distribution channels 5, s is the effective flow area of ​​the distribution channels 5, and v is the flow velocity of the distribution channels 5.

[0035] The effective flow area of ​​the flow distribution channel 5 is s=wd, wherein w is the width of the flow distribution channel 5 and d is the thickness of the cover plate 1 .

[0036] The flow velocity v of the distribution channel 5 is (3.14*n*C*R) / 30, wherein n is the number of the distribution channels 5 , C is the correction coefficient, C=1-1.3, and R is the centerline radius of the distribution channel 5 .

[0037] A front flow channel is formed between adjacent front blades 2, and a back flow channel is formed between adjacent back blades 3. In order to achieve the same pressure gradient between the front blades 2 and the back blades 3, the profiles of the front blades 2 and the back blades 3 are the same, but the front flow rate is smaller than the back flow rate. In order to reduce the axial vortex of the distribution channel 5 and improve the efficiency, the flow cross-sectional area of ​​the back flow channel is reduced. In one embodiment, the flow cross-sectional area of ​​the back flow channel is 0.3 to 0.8 times the flow cross-sectional area of ​​the front flow channel, and the flow cross-sectional area of ​​the back flow channel is preferably 0.5 times the flow cross-sectional area of ​​the front flow channel.

[0038] It is worth noting that the cover plate 1 is provided with a splitter blade 8 between adjacent back blades 3. The inlet position of the splitter blade 8 is located at one-third of the back flow channel. The inlet placement angle of the splitter blade 8 is (20°~29°)-C, where C=(2°-5°). The splitter blade 8 separates the back flow channel into two splitter channels. The cover plate 1 is provided with at least one connecting hole 9 in the splitter channel. In this embodiment, two connecting holes 9 are provided in each splitter channel. The residual axial force can be further eliminated by providing the connecting holes 9. The connecting holes 9 are arranged on both sides of the splitter blade 8, which can achieve pressure balance on both sides of the splitter blade 8.

[0039] The front blades 2 and the back blades 3 are arranged as follows.

[0040] Reference Figure 5 and Figure 6 As shown, the angle of the inlet placement angle a1 of the front blade 2 is (19°-35°)-C1, where C1=2°-5°, the angle of the wrap angle b of the front blade 2 is (110°-150°)+C2, where C2=(2°-5°), and the water inlet velocity u1 of the front blade 2 is =πD1n1 / 60, where D1 is the water inlet diameter of the front blade 2, and the water inlet of the front blade 2 here refers to the water inlet formed by the ends of all the front blades 2, and n1 is the number of front blades 2.

[0041] The outlet height of the front blade 2 is h1 = K b (2gH) 1 / 2 / n1, where K b is the correction parameter, H is the pump head, and n1 is the number of front blades 2.

[0042] In the design of the front blade 2, the front blade 2 inlet height is higher than the front blade 2 outlet height, the back blade 3 outlet height h2 is lower than the front blade 2 outlet height h1, and the back blade 3 inlet height is lower than the back blade 3 outlet height h2.

[0043] In order to further improve the cavitation resistance, the single-sided double-suction impeller structure of the present application can be used in combination with an inducer, which is arranged at the front side of the single-sided double-suction impeller, and the outlet angle of the blades in the inducer is close to the inclination angle of the guide plate 7, so as to Figure 5 As a reference angle, the outlet edge of the blade in the inducer is offset to the left by 3°-5° in the circumferential direction of the distribution channel 5.

[0044] Therefore, the present application adopts the setting of a single-sided double-suction impeller structure, and the impeller structure can achieve the function of single-sided double suction while ensuring good cavitation resistance and axial force balance, and the structure is simple and compact.

[0045] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A single-sided double-suction impeller structure, characterized in that: It comprises a cover plate (1), a plurality of front blades (2) arranged on the front side of the cover plate (1), and a plurality of back blades (3) arranged on the back side of the cover plate (1), wherein the front blades (2) and the back blades (3) have the same profile. The cover plate (1) is provided with a plurality of flow distribution channels (5), which are arranged circumferentially and spaced apart around the center of the cover plate (1), each of the flow distribution channels (5) being arranged at the inlet of the front blade (2) and the back blade (3), and each of the flow distribution channels (5) being arranged between two adjacent front blades (2) and two adjacent back blades (3).

2. A single-sided double-suction impeller structure according to claim 1, characterized in that: The cover plate (1) is provided with a plurality of drainage channels (6), which are arranged at intervals in the circumferential direction around the center of the cover plate (1), each of the drainage channels (6) is communicated with each of the flow distribution channels (5), and a drainage plate (7) is arranged in each of the drainage channels (6).

3. A single-sided double-suction impeller structure according to claim 2, characterized in that: The guide plate (7) is formed with a guide slope which is inclined toward the flow distribution channel (5) and toward the side of the back blade (3).

4. The single-sided double-suction impeller structure according to claim 2, characterized in that: The drainage channel (6) and the distribution channel (5) are both arranged in a fan shape, and the radii of the upper arc line and the lower arc line of the drainage channel (6) and the distribution channel (5) are the same.

5. The single-sided double-suction impeller structure according to claim 4, characterized in that: The distance between the upper arc line of the distribution channel (5) and the ends of the inlets of the front blade (2) and the back blade (3) is 3-5 mm.

6. The single-sided double-suction impeller structure according to claim 4, characterized in that: The diameter of the circle formed by the upper arc lines of all the drainage channels (6) and the distribution channels (5) is close to the diameter of the water inlet formed by the front blades (2).

7. The single-sided double-suction impeller structure according to claim 1, characterized in that: The front flow rate of the single-sided double-suction impeller structure is q1, and the back flow rate of the single-sided double-suction impeller structure is q2. The single-sided double-suction impeller structure is configured with q2=kq1, wherein k is a constant, k=0.2-0.7; The back flow rate of the single-sided double-suction impeller structure is q2=nsv, wherein n is the number of the distribution channels (5), s is the effective flow area of ​​the distribution channels (5), and v is the flow velocity of the distribution channels (5); The effective flow area of ​​the flow distribution channel (5) is s=wd, wherein w is the width of the flow distribution channel (5) and d is the thickness of the cover plate (1); The flow velocity v of the distribution channel (5) is (3.14*n*C*R) / 30, wherein n is the number of the distribution channels (5), C is the correction coefficient, C=1-1.3, and R is the centerline radius of the distribution channel (5).

8. The single-sided double-suction impeller structure according to claim 1, characterized in that: A front flow channel is formed between adjacent front blades (2), and a back flow channel is formed between adjacent back blades (3), and the flow cross-sectional area of ​​the back flow channel is 0.3 to 0.8 times the flow cross-sectional area of ​​the front flow channel.

9. The single-sided double-suction impeller structure according to claim 8, characterized in that: The cover plate (1) is provided with a splitter blade (8) between adjacent back blades (3), and the inlet position of the splitter blade (8) is located at one third of the back flow passage.

10. The single-sided double-suction impeller structure according to claim 9, characterized in that: The splitter blade (8) divides the back flow passage into two splitter passages, and the cover plate (1) is provided with at least one connecting hole (9) in the splitter passage.

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