Centrifugal pump wear ring sealing structure

Abstract

The invention relates to the field of centrifugal pumps, in particular to a centrifugal pump wear ring sealing structure which is characterized in that a plurality of pump body wear ring pieces are arranged between two pump body wear ring cover rings, and pump body wear ring gaskets are arranged between every two adjacent pump body wear ring pieces and between the pump body wear ring cover rings and the adjacent pump body wear ring pieces respectively; a plurality of impeller wear ring pieces are arranged between the two impeller wear ring cover rings, and impeller wear ring gaskets are arranged between every two adjacent impeller wear ring pieces and between the impeller wear ring cover rings and the adjacent impeller wear ring pieces respectively. Operation gaps are formed between the pump body wear ring cover ring and the impeller wear ring cover ring which correspond to each other and between the pump body wear ring ring piece and the impeller wear ring ring piece which correspond to each other, annular open grooves are formed between the pump body wear ring gasket and the impeller wear ring gasket which correspond to each other, and the operation gaps communicate with the two annular open grooves located in the two opposite sides of the operation gaps. The multiple operation gaps are arranged in a staggered mode in the radial direction, and a continuous H-shaped labyrinth channel is formed between the pump body wear ring and the impeller wear ring.

Description

Technical Field

[0001] The invention relates to the technical field of centrifugal pump sealing, in particular to a centrifugal pump orifice ring sealing structure. Background Art

[0002] In a centrifugal pump, the mouth ring (also known as the sealing ring or clearance ring) is a key structural element located between the pump body and the impeller. Its main function is to prevent fluid leakage, reduce axial force and ensure sealing effect by forming a seal and gap control between the impeller and the pump casing. During the high-speed rotation of the centrifugal pump impeller, a small radial displacement may occur due to thermal expansion, manufacturing errors or installation deviations. If the mouth ring gap is too small, the impeller may directly contact the pump casing, causing severe wear, damage or even pump failure. Appropriate mouth ring gap provides space to accommodate these deviations, prevents mechanical interference between components, and improves the operating reliability and service life of the pump.

[0003] The design of the ring and its clearance size have an important influence on the performance of the centrifugal pump. The size and shape of the centrifugal pump's ring clearance directly affect the pump's leakage, efficiency and operating stability. Especially in the pursuit of high efficiency and low energy consumption of pump design, the optimization of the ring clearance is particularly critical.

[0004] Existing centrifugal pump mouth rings, such as the utility model patent with application number CN201420753542.1, discloses a centrifugal pump impeller mouth ring and pump body sealing ring structure, including an impeller mouth ring and a pump body sealing ring that cooperate with each other, and a labyrinth sealing groove is opened in the outer surface area of ​​the impeller mouth ring.

[0005] The existing centrifugal pump mouth ring is a single-sided groove structure, which only has grooves on the pump body mouth ring or the impeller mouth ring, and cannot effectively prevent liquid backflow and leakage, which affects the efficiency and operation stability of the pump. Summary of the invention

[0006] The object of the present invention is to provide a centrifugal pump mouth ring sealing structure, which improves the hydraulic performance of the pump while ensuring that the mouth ring gap meets the operating clearance, so as to solve the defects mentioned in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A centrifugal pump mouth ring sealing structure comprises a pump body mouth ring and an impeller mouth ring which cooperate with each other, wherein the pump body mouth ring comprises two pump body mouth ring cover rings arranged along the axial direction, a plurality of pump body mouth ring ring sheets arranged evenly at intervals are arranged between the two pump body mouth ring cover rings, and a pump body mouth ring gasket is arranged between two adjacent pump body mouth ring ring sheets and between the pump body mouth ring cover ring and the adjacent pump body mouth ring ring sheets; the impeller mouth ring comprises two impeller mouth ring cover rings arranged along the axial direction, a plurality of impeller mouth ring ring sheets arranged evenly at intervals are arranged between the two impeller mouth ring cover rings, the impeller mouth ring sheets correspond to the pump body mouth ring sheets one by one, and an impeller mouth ring gasket is arranged between two adjacent impeller mouth ring ring sheets and between the impeller mouth ring cover ring and the adjacent impeller mouth ring ring sheets.

[0009] As a further improvement, operating gaps are respectively provided between the corresponding pump body ring cover ring and the impeller ring cover ring, and between the corresponding pump body ring sheet and the impeller ring sheet, and annular grooves are respectively provided between the corresponding pump body ring gasket and the impeller ring gasket, and the operating gap connects the two annular grooves located on opposite sides thereof.

[0010] As a further improvement, the plurality of operating gaps are staggered in the radial direction.

[0011] As a further improvement, the radial width of the operating gap is A, the axial thickness of the pump body mouth ring gasket and the impeller mouth ring gasket are both B, the axial thickness of the pump body mouth ring sheet and the impeller mouth ring sheet are both C, the minimum radial distance between the operating gap and the inner circumferential wall of the annular groove and the minimum radial distance between the operating gap and the outer circumferential wall of the annular groove are both D, the minimum radial distance between two adjacent operating gaps is E, and the maximum axial displacement of the impeller is S; D≥4A, E≥2D, B≥S, C≥2B.

[0012] As a further improvement, the pump body mouth ring cover ring, the pump body mouth ring ring sheet, and the pump body mouth ring gasket are coaxially arranged and fit in pairs; the impeller mouth ring cover ring, the impeller mouth ring ring sheet, and the impeller mouth ring gasket are coaxially arranged and fit in pairs.

[0013] As a further improvement, the pump body mouth ring piece includes a pump body mouth ring piece I and a pump body mouth ring piece II with different inner diameters, and the pump body mouth ring piece I and the pump body mouth ring piece II are arranged alternately.

[0014] As a further improvement, the impeller mouth ring segment includes an impeller mouth ring segment I and an impeller mouth ring segment II with different outer diameters, and the impeller mouth ring segment I and the impeller mouth ring segment II are arranged alternately.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] Multiple operating gaps are staggered radially to form a continuous H-shaped labyrinth channel between the pump body ring and the impeller ring, which effectively improves the anti-backflow and anti-leakage capabilities between the pump body ring and the impeller ring, thereby improving the efficiency and operation stability of the centrifugal pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0019] Figure 2 yes Figure 1 An enlarged schematic diagram of the pump body mouth ring and impeller mouth ring in part I.

[0020] Figure 3 It is a schematic diagram of the existing mouth ring structure.

[0021] Figure 4 This is the performance curve of the existing pump under the mouth ring.

[0022] Figure 5 Schematic diagram of the improved design of the mouth ring structure with L=22mm.

[0023] Figure 6 Schematic diagram of the improved design of the mouth ring structure with L=25mm.

[0024] Figure 7 Schematic diagram of the improved design of the mouth ring structure with L=38mm.

[0025] Figure 8 This is the flow-head curve.

[0026] Fig. 9 This is the flow-shaft power curve.

[0027] Fig.10 This is the flow-pump efficiency curve.

[0028] In the figure: 1-pump casing; 2-impeller; 3-pump body mouth ring; 4-impeller mouth ring; 5-pump body mouth ring cover ring; 6-pump body mouth ring ring piece; 7-pump body mouth ring gasket; 8-impeller mouth ring cover ring; 9-impeller mouth ring ring piece; 10-impeller mouth ring gasket; 11-operating clearance; 12-annular groove; 61-pump body mouth ring ring piece I; 62-pump body mouth ring ring piece II; 91-impeller mouth ring ring piece I; 92-impeller mouth ring ring piece II. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0030] like Figure 1 and Figure 2 As shown, the centrifugal pump mouth ring sealing structure includes a pump body mouth ring 3 and an impeller mouth ring 4 that cooperate with each other, and the pump body mouth ring 3 is nested outside the impeller mouth ring 4; the impeller mouth ring 4 is sleeved on the outer wall of the impeller 2 inlet, and the pump body mouth ring 3 is embedded in the inner wall of the pump casing 1 of the centrifugal pump.

[0031] The pump body mouth ring 3 includes two pump body mouth ring cover rings 5 ​​arranged in the axial direction, a plurality of pump body mouth ring slices 6 arranged evenly spaced are arranged between the two pump body mouth ring cover rings 5, and pump body mouth ring gaskets 7 are respectively arranged between two adjacent pump body mouth ring slices 6 and between the pump body mouth ring cover ring 5 and the adjacent pump body mouth ring slices 6. In this embodiment, the pump body mouth ring cover ring 5, the pump body mouth ring slice 6, and the pump body mouth ring gasket 7 are coaxially arranged in annular shapes and fit in pairs, and the outer diameters of the pump body mouth ring cover ring 5, the pump body mouth ring slice 6, and the pump body mouth ring gasket 7 are consistent, and a step surface for abutting against one of the pump body mouth ring cover rings 5 ​​is provided on the inner wall of the pump housing 1, and the other pump body mouth ring cover ring 5 can be fixedly installed on the pump housing 1 by screws, so that the pump body mouth ring slice 6 and the pump body mouth ring gasket 7 located on the inner side are pressed by the two pump body mouth ring cover rings 5.

[0032] The impeller ring 4 includes two impeller ring cover rings 8 arranged in the axial direction, a plurality of impeller ring segments 9 evenly spaced are arranged between the two impeller ring cover rings 8, the impeller ring segments 9 correspond one to one with the pump body ring segments 6, and impeller ring gaskets 10 are respectively arranged between two adjacent impeller ring segments 9 and between the impeller ring cover ring 8 and the adjacent impeller ring segments 9. In this embodiment, the impeller ring cover ring 8, the impeller ring piece 9, and the impeller ring gasket 10 are coaxially arranged in annular shapes and fit in pairs. The inner diameters of the impeller ring cover ring 8, the impeller ring piece 9, and the impeller ring gasket 10 are consistent. A step surface for abutting one of the impeller ring cover rings 8 is provided on the outer wall at the inlet of the impeller 2. The other impeller ring cover ring 8 can be fixed on the outer wall at the inlet of the impeller 2 by screws, so that the impeller ring piece 9 and the impeller ring gasket 10 located on the inner side are pressed by the two impeller ring cover rings 8.

[0033] An operating gap 11 is provided between the corresponding pump body mouth ring cover ring 5 and the impeller mouth ring cover ring 8, and between the corresponding pump body mouth ring piece 6 and the impeller mouth ring piece 9. The operating gap 11 is a conventional pump mouth ring design gap. An annular groove 12 is provided between the corresponding pump body mouth ring gasket 7 and the impeller mouth ring gasket 10. The operating gap 11 connects the two annular grooves 12 located on the opposite sides thereof.

[0034] In this embodiment, the pump body ring piece 6 includes a pump body ring piece I 61 and a pump body ring piece II 62 with different inner diameters, the inner diameter of the pump body ring piece I 61 is smaller than the inner diameter of the pump body ring piece II 62, and the pump body ring piece I 61 and the pump body ring piece II 62 are staggered; the impeller ring piece 9 includes an impeller ring piece I 91 and an impeller ring piece II 92 with different outer diameters, the outer diameter of the impeller ring piece I 91 is smaller than the outer diameter of the impeller ring piece II 92, the impeller ring piece I 91 and the impeller ring piece II 92 are staggered, and the impeller ring piece The ring piece I91 and the impeller ring piece II92 correspond to the pump body ring piece I61 and the pump body ring piece II62 respectively; the inner diameter of the pump body ring cover ring 5 is consistent with the inner diameter of the pump body ring piece I61 or the inner diameter of the pump body ring piece II62, and the inner diameter of the pump body ring cover ring 5 is inconsistent with the inner diameter of the adjacent pump body ring piece 6; the outer diameter of the impeller ring cover ring 8 is consistent with the outer diameter of the impeller ring piece I91 or the outer diameter of the impeller ring piece II92, and the outer diameter of the impeller ring cover ring 8 is inconsistent with the outer diameter of the adjacent impeller ring piece 9. An operating gap 11 is provided between the corresponding pump body ring cover ring 5 and the impeller ring cover ring 8, between the corresponding pump body ring piece I61 and the impeller ring piece I91, and between the corresponding pump body ring piece II62 and the impeller ring piece II92.

[0035] By adopting the above structure, multiple operating gaps 11 are staggered in the radial direction, thereby forming a continuous H-shaped labyrinth channel between the pump body mouth ring 3 and the impeller mouth ring 4, and the long and short raised tooth structures are arranged alternately. Finally, the axial dimension of the mouth ring is smaller than L, and L is the longest axial design dimension of the mouth ring.

[0036] Under the premise of ensuring that the design of the operating clearance 11 meets the requirements, the anti-backflow and anti-leakage capabilities between the pump body mouth ring 3 and the impeller mouth ring 4 are effectively improved, thereby improving the efficiency and operation stability of the centrifugal pump.

[0037] In this embodiment, the radial width of the operating gap 11 is A; the axial thickness of the pump body ring gasket 7 and the impeller ring gasket 10 is B; the axial thickness of the pump body ring plate 6 and the impeller ring plate 9 is C; the minimum radial distance between the operating gap 11 and the inner circumferential wall of the annular groove 12 and the minimum radial distance between the operating gap 11 and the outer circumferential wall of the annular groove 12 are both D. Specifically, the minimum radial distance between the operating gap 11 and the inner circumferential wall of the annular groove 12 is the minimum radial distance between the outer circumferential wall of the impeller ring plate I91 and the impeller ring gasket 10. The minimum radial distance between the operating gap 11 and the outer peripheral wall of the annular groove 12 is the radial distance between the inner peripheral wall of the pump body mouth ring segment II 62 and the inner peripheral wall of the pump body mouth ring gasket 7; the minimum radial distance between two adjacent operating gaps 11 is E, specifically, the minimum radial distance between two adjacent operating gaps 11 is the radial distance between the inner peripheral wall of the pump body mouth ring segment I 61 and the outer peripheral wall of the impeller mouth ring segment II 92; the maximum axial displacement of the impeller 2 is S; D≥4A, E≥2D, B≥S, C≥2B.

[0038] Taking OHA80-400 pump as an example, the design point flow rate is 284m 3 / h, speed 2980r / min, diameter of the mouth ring gap is 207mm, according to API 610 standard (full name: "Design, Manufacturing and Test Specification for Centrifugal Pumps for Petroleum and Natural Gas Industry"), the gap A = 0.5mm, the axial length L of the mouth ring is 22mm, and the maximum axial design size of the mouth ring is 38mm.

[0039] The distribution of proto-oral rings is as follows Figure 3 As shown, after installation, the performance obtained through CFD calculation is as follows Figure 4 As shown, the highest efficiency is 71.81%.

[0040] The sealing structure of the H-shaped labyrinth channel designed according to the present invention is as follows Figure 5-7 As shown, D = 4A = 2mm, E = 5mm (≥ 2D = 4mm), take the maximum axial displacement of the impeller S = 1mm, B = S = 1mm, C = 2mm (≥ 2B = 2mm), where Figure 5 Middle L = 22mm, Figure 6Middle L = 25mm, Figure 7 In the case of L=38mm, the hydraulic performance under the above different mouth ring conditions was obtained based on the same CFD calculation method. Figure 8 The comparison results of lift under different flow conditions are shown in the figure. It can be seen that the improved mouth ring seal structure improves the lift under each flow condition. Fig. 9 The middle is the shaft power curve. It can be seen that under different flow conditions, the improved design of the ring reduces the shaft power. Fig.10 This is the pump efficiency curve. It can be seen that under different flow conditions, the improved design of the ring improves the pump efficiency and does not change the highest efficiency flow point.

[0041] Table 1 Pump efficiency values ​​under different fluid conditions

[0042]

[0043] The following table shows the efficiency improvement values ​​at different flow rates. It can be seen that increasing the number of stacking layers can continuously improve the pump efficiency. For example, at a rated flow rate of 284m 3 / h, the efficiency improvement value increased from 5.44% to 6.87%, so when using the patented method of the present invention, the number of ring stacking layers can be increased as much as possible under the condition allowed by L.

[0044]

[0045] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope 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 mouth ring sealing structure, comprising a pump body mouth ring and an impeller mouth ring that cooperate with each other, characterized in that: The pump body mouth ring comprises two pump body mouth ring cover rings arranged along the axial direction, a plurality of pump body mouth ring ring sheets arranged evenly at intervals are arranged between the two pump body mouth ring cover rings, and a pump body mouth ring gasket is respectively arranged between two adjacent pump body mouth ring ring sheets and between the pump body mouth ring cover ring and the adjacent pump body mouth ring ring sheet; the impeller mouth ring comprises two impeller mouth ring cover rings arranged along the axial direction, a plurality of impeller mouth ring ring sheets arranged evenly at intervals are arranged between the two impeller mouth ring cover rings, the impeller mouth ring sheets correspond one to one with the pump body mouth ring sheets, and an impeller mouth ring gasket is respectively arranged between two adjacent impeller mouth ring ring sheets and between the impeller mouth ring cover ring and the adjacent impeller mouth ring ring sheet.

2. The centrifugal pump port ring sealing structure according to claim 1, characterized in that: An operating gap is provided between the corresponding pump body ring cover ring and the impeller ring cover ring, and between the corresponding pump body ring sheet and the impeller ring sheet, and an annular groove is provided between the corresponding pump body ring gasket and the impeller ring gasket, and the operating gap connects the two annular grooves located on opposite sides thereof.

3. The centrifugal pump port ring sealing structure according to claim 2, characterized in that: The plurality of operating gaps are staggeredly arranged along the radial direction.

4. The centrifugal pump port ring sealing structure according to claim 3, characterized in that: The radial width of the operating gap is A, the axial thickness of the pump body ring gasket and the impeller ring gasket is B, the axial thickness of the pump body ring plate and the impeller ring plate is C, the minimum radial distance between the operating gap and the inner peripheral wall of the annular groove and the minimum radial distance between the operating gap and the outer peripheral wall of the annular groove are D, the minimum radial distance between two adjacent operating gaps is E, and the maximum axial displacement of the impeller is S; D≥4A, E≥2D, B≥S, C≥2B.

5. The centrifugal pump port ring sealing structure according to claim 1, characterized in that: The pump body mouth ring cover ring, the pump body mouth ring ring sheet, and the pump body mouth ring gasket are coaxially arranged and fit in pairs; the impeller mouth ring cover ring, the impeller mouth ring ring sheet, and the impeller mouth ring gasket are coaxially arranged and fit in pairs.

6. The centrifugal pump port ring sealing structure according to claim 1, characterized in that: The pump body mouth ring piece comprises a pump body mouth ring piece I and a pump body mouth ring piece II with different inner diameters, and the pump body mouth ring piece I and the pump body mouth ring piece II are arranged alternately.

7. The centrifugal pump port ring sealing structure according to claim 1, characterized in that: The impeller mouth ring piece comprises an impeller mouth ring piece I and an impeller mouth ring piece II with different outer diameters, and the impeller mouth ring piece I and the impeller mouth ring piece II are arranged alternately.

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