A method for hydraulic design of submersible pump

Abstract

This application relates to a hydraulic design method for submersible pumps, and pertains to the technical field of pumps. The meridional streamline function of the impeller satisfies the following relationship: Let the meridional streamline function be F(x), then... When 0 <x<x 1 hour, When x 1 <x<x 2 hour, When x 2 <x<x 3 hour, In the formula: x is the horizontal distance from the impeller inlet; x 1 It is the horizontal distance between the intersection of the inlet arc segment and the straight segment and the impeller inlet; x 2 It is the horizontal distance between the intersection of the arc segment and the straight segment at the outlet and the impeller inlet; x 3 It is the horizontal length of the entire impeller meridional plane; k is a coefficient, and c is a constant. This application has the advantages of reducing wear caused by the impact of silt on the guide shell, and improving the pump's operational reliability and service life.

Description

A Hydraulic Design Method for Submersible Pumps Technical Field

[0001] This application relates to the technical field of pumps, particularly to a hydraulic design method for submersible pumps. Background Art

[0002] High-speed submersible pumps for wells are important equipment for extracting groundwater and are widely used in rural areas, factories, mines, water supply companies, geothermal development, oil fields and other places or fields. At present, the multi-stage centrifugal pump hydraulic models adopted by high-speed submersible pumps for wells are generally designed according to the conditions of clear water medium, with good hydraulic efficiency and medium passing ability. However, in the actual application process, the water body transported by the centrifugal pump contains a large amount of sediment. When the sediment-carrying water body enters the guide vane, it will impact the guide shell. Under long-term action, the guide shell will be worn and damaged, thus affecting the operation of the entire high-speed submersible pump for wells. Summary of the Invention

[0003] Aiming at the deficiencies existing in the prior art, one of the purposes of this application is to provide a hydraulic design method for submersible pumps, which has the advantages of being able to reduce the wear caused by the impact of sediment on the guide shell, and improving the operation reliability and service life of the pump.

[0004] The above purpose of this application is achieved through the following technical solutions:

[0005] A hydraulic design method for submersible pumps, where the meridian streamline function of the impeller conforms to the following relationship:

[0006] Let the meridian streamline function be F(x), then

[0007] When 0 < x < x1,

[0008] When x1 < x < x2,

[0009] When x2 < x < x3,

[0010] In the formula: x is the horizontal distance from the impeller inlet; x1 is the horizontal distance between the intersection of the inlet arc section and the straight line section and the impeller inlet; x2 is the horizontal distance between the intersection of the outlet arc section and the straight line section and the impeller inlet; x3 is the horizontal length of the entire impeller meridian plane; k is a coefficient, and c is a constant value.

[0011] This application can be further configured in a preferred example as follows: The specific parameter formula of the impeller is as follows:

[0012]

[0013] d2 = 9.35K(n) s / 100) -1 / 2 (Q / n) 1 / 3 (6)

[0014]

[0015] d5 = d3 - 2b1 - 2b2; (8)

[0016]

[0017]

[0018]

[0019] 1.1≤S1 / S2≤1.3; (12)

[0020]

[0021] In the formula: d1 is the impeller hub diameter; M n [τ] is the torque; [τ] is the allowable shear stress of the material; d2 is the impeller inlet diameter; n s d1 is the pump's specific speed; K is the correction coefficient; Q is the design flow rate; n is the rotational speed; b1 is the thickness of the front cover plate; b2 is the impeller clearance; d3 is the inner diameter of the guide shell; b3 is the dynamic and static clearance; θ is the impeller outlet tilt angle; d5 is the impeller outlet diameter.

[0022] In a preferred embodiment, this application can be further configured such that: the guide vane inlet placement angle β should satisfy...

[0023] The beneficial effects of this invention are: the well submersible pump designed using this method extends the service life of the pump in media containing solid particles, and effectively improves the operational reliability and hydraulic performance of the submersible pump, thus having a better application prospect in groundwater extraction. Attached Figure Description

[0024] Figure 1 is a meridional view of the impeller of the present invention;

[0025] Figure 2 is a radial view of the impeller and guide vanes of the present invention.

[0026] Reference numerals: 1. Impeller; 2. Guide shell. Detailed Implementation

[0027] The present application will be further described in detail below with reference to the accompanying drawings.

[0028] Referring to FIGS. 1 and 2, a submersible pump hydraulic design method disclosed in the present application is provided. In this method, the impeller outlet section is an arc section, which is beneficial to increasing the internal flow-through area of the impeller and improving the hydraulic efficiency of the impeller. The fluid medium in the impeller directly enters the guide vane, reducing the impact on the guide shell and extending the service life of the submersible pump for high-speed wells. To avoid wear and damage of the guide shell, the present invention determines the impeller meridian geometry through the following functional relationship.

[0029]

[0030] When 0 < x < x1,

[0031] When x1 < x < x2,

[0032] When x2 < x < x3,

[0033] In the formula: x is the horizontal distance from the impeller inlet, unit: m; x1 is the horizontal distance from the intersection of the inlet arc section and the straight line section to the impeller inlet, unit: m; x2 is the horizontal distance from the intersection of the outlet arc section and the straight line section to the impeller inlet, unit: m; x3 is the horizontal length of the entire impeller meridian, unit: m; k is a coefficient related to the velocity distribution. When mainly considering efficiency, k = 0.08 - 0.1; when considering both efficiency and cavitation, k = 0.06 - 0.08; when mainly considering cavitation, k = 0.04 - 0.06; c is a constant value, generally taking 0 < c < tanθ, where θ is the impeller outlet inclination angle.

[0034] The specific parameter formulas of the impeller are as follows: <00QQ108>

[0035]

[0036] d2 = 9.35K(n s / 100) -1 / 2 (Q / n) 1 / 3 ; (6)

[0037]

[0038] d5 = d3 - 2b1 - 2b2; (8)

[0039]

[0040]

[0041]

[0042] 1.1≤S1 / S2≤1.3; (12)

[0043]

[0044] x1 = (0.45 ~ 0.55)x2; (14)

[0045]

[0046] x3 = (1.9 ~ 2.1)x2; (16)

[0047] In the formula: d1 is the impeller hub diameter, in meters (m); M n [τ] is torque, unit: N·m; [τ] is the allowable shear stress of the material, unit: Pa; d2 is the impeller inlet diameter, unit: m; n s ... 3 / s; n is the rotational speed, unit: r / min; b1 is the thickness of the front cover plate, unit: mm; b2 is the impeller clearance, unit: mm, generally greater than 1.5mm; d3 is the inner diameter of the guide shell, unit: m; b3 is the dynamic and static clearance, unit: mm; θ is the impeller outlet tilt angle, unit: degrees; d5 is the impeller outlet diameter, unit: m.

[0048] The guide vane inlet placement angle β should meet the following requirements.

[0049] The implementation principle of this embodiment is as follows: the above design can extend the service life of the pump in media containing solid particles, and effectively improve the operational reliability and hydraulic performance of the submersible pump, and has better application prospects when extracting groundwater.

[0050] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A hydraulic design method for a submersible pump, characterized in that: The meridional streamline function of the impeller satisfies the following relationship: Let the meridional streamline function be F(x), then When \(0 \lt x \lt x_1\), (2) When x1 < x < x2, When x2 < x < x3, (4) Where: x is the horizontal distance from the impeller inlet; x1 is the horizontal distance from the intersection of the inlet arc segment and the straight segment to the impeller inlet; x2 is the horizontal distance from the intersection of the outlet arc segment and the straight segment to the impeller inlet; x3 is the horizontal length of the entire impeller meridional plane; k is a coefficient, and c is a constant value; the specific impeller parameters are as follows: In the formula: d1 is the impeller hub diameter; Torque; The allowable shear stress of the material; The impeller inlet diameter; is the pump's specific speed; K is the correction factor; Q is the design flow rate; n is the rotational speed; b1 is the thickness of the front cover plate; b2 is the impeller clearance. d3 is the diameter of the inner wall of the guide shell; b3 is the dynamic-static gap; d5 is the impeller outlet inclination angle; d5 is the impeller outlet diameter; guide vane inlet placement angle. Should meet

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