An elastic porous housing for reducing pressure pulsation in the dynamic-static interference region of a mixed-flow pump

Abstract

This invention provides an elastic porous shell for reducing pressure pulsation in the dynamic-static interference zone of a mixed-flow pump, belonging to the technical field of mixed-flow pump shells. The elastic porous shell includes a sudden-change section, which is the shell between the guide vane inlet and the impeller blade outlet, and represents the dynamic-static interference zone of the mixed-flow pump. The sudden-change section is an outwardly convex arc-shaped structure, with a porous elastic wall surface on its inner side, and a gas buffer layer between the sudden-change section and the porous elastic wall surface. This invention can significantly reduce pressure pulsation in the dynamic-static interference zone of a mixed-flow pump, thereby improving the efficiency of the mixed-flow pump.

Description

Technical Field

[0001] This invention belongs to the technical field of mixed-flow pump housings, specifically an elastic porous housing for reducing pressure pulsation in the dynamic-static interference zone of a mixed-flow pump. Background Technology

[0002] A guide vane mixed-flow pump, also known as an oblique-flow pump, is a type of vane pump whose performance and structure fall between those of centrifugal and axial-flow pumps. It transports liquids through the combined action of centrifugal force and thrust generated by the impeller's rotation, exhibiting both axial and radial flow characteristics, with the liquid exiting the impeller at an oblique angle. This unique working principle combines the advantages of both centrifugal and axial-flow pumps while overcoming their respective disadvantages, making it a crucial component in modern fluid transport engineering.

[0003] For hydraulic machinery, pressure pulsation in high-load areas is primarily driven by the dynamic-static interference effect between the impeller and the moving guide vanes. The flow-induced noise generated by pressure pulsation not only exacerbates equipment vibration and wear, shortening its service life, but also causes noise pollution, becoming one of the main bottlenecks restricting the industry's energy efficiency and green transformation. Existing methods for optimizing pressure pulsation focus on optimizing the geometric parameters of mechanical equipment such as blades, which are complex to operate and cannot achieve real-time dynamic adjustment. Summary of the Invention

[0004] To address the problems in the prior art, the present invention provides an elastic porous housing for reducing pressure pulsation in the dynamic-static interference zone of a mixed-flow pump.

[0005] Technical solution: An elastic porous shell for reducing pressure pulsation in the dynamic-static interference zone of a mixed-flow pump, the elastic porous shell including a pump casing abrupt change section, the pump casing abrupt change section being the shell between the guide vane inlet and the impeller blade outlet, the pump casing abrupt change section being the dynamic-static interference zone of the mixed-flow pump; the pump casing abrupt change section is an outwardly convex arc-shaped structure, the inner side of the pump casing abrupt change section is provided with a porous elastic wall surface, and a gas buffer layer is provided between the pump casing abrupt change section and the porous elastic wall surface.

[0006] Furthermore, a sealed space is formed between the porous elastic wall and the abrupt change section of the pump casing, and the space is filled with gas as a gas buffer layer. Several micropores that do not penetrate the porous elastic wall are distributed on the porous elastic wall away from the abrupt change section of the pump casing.

[0007] Furthermore, the elastic porous outer shell also includes a uniform pump shell section, which is connected to the abrupt pump shell section. The uniform pump shell section is a shell connected to the guide vane body.

[0008] Furthermore, the flexible porous housing is used in a guide vane mixed-flow pump.

[0009] Furthermore, the outer casing of the guide vane mixed flow pump includes an inlet section casing, an impeller chamber section, a guide vane body section casing, and an outlet bend connected in sequence; the impeller of the guide vane mixed flow pump is located in the impeller chamber, impeller blades are installed on the impeller, and guide vanes are installed on the guide vane body section casing.

[0010] Furthermore, the thickness of the porous elastic wall and the diameter of the micropores on the wall are:

[0011]

[0012]

[0013]

[0014] Where b is the thickness of the porous wall, d is the diameter of the micropores on the porous wall, D is the diameter of the uniform section of the pump casing, Q is the rated flow rate of the mixed flow pump, and V is the flow velocity of the liquid flowing through the mixed flow pump.

[0015] Furthermore, the gas pressure of the sealed gas buffer layer is:

[0016]

[0017] in, For the gas pressure of the sealed buffer layer, V is the saturated vapor pressure of the liquid flowing through the mixed-flow pump; V is the flow velocity of the liquid flowing through the mixed-flow pump. For the rated head of the mixed-flow pump, For emptying, This is the acceleration due to gravity.

[0018] Beneficial effects: The present invention features a porous elastic wall and a gas buffer layer. When the mixed-flow pump is working, the pressure pulsation generated by cavitation causes the porous elastic wall to deform. The gas buffer layer buffers and promotes the conversion of energy into jet kinetic energy and rebound potential energy. The porous elastic wall moves elastically, thereby alleviating the pressure pulsation. The porous structure can not only reduce pressure pulsation and flow-induced noise, but also generate velocity slip and reduce flow friction, thus achieving the purpose of noise reduction and efficiency improvement. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the elastic porous shell used in the present invention to reduce pressure pulsation in the dynamic-static interference region of a mixed-flow pump.

[0020] Among them, 101 is the uniform section of the pump casing; 102 is the abrupt change section of the pump casing; 103 is the porous elastic wall; 104 is the gas buffer layer; 2 is the guide vane; 3 is the impeller blade; and 4 is the outlet bend. Detailed Implementation

[0021] The technical solution of the present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited to the embodiments described.

[0022] Example 1

[0023] This embodiment provides an elastic porous housing for reducing pressure pulsation in the dynamic-static interference zone of a mixed-flow pump. The elastic porous housing is used in a guide vane type mixed-flow pump. The guide vane type mixed-flow pump housing includes an inlet section housing, an impeller chamber section, a guide vane body section housing, and an outlet bend 4 connected in sequence. The impeller of the guide vane type mixed-flow pump is located in the impeller chamber, and impeller blades 3 are installed on the impeller. Guide vanes 2 are installed on the guide vane body section housing.

[0024] The guide vane body section shell is defined as the uniform section 101 of the pump shell; the shell between the inlet of the guide vane 2 and the outlet of the impeller blade 3 is defined as the abrupt change section 102 of the pump shell, which is a dynamic-static interference zone.

[0025] Working principle of guide vane mixed flow pump: The impeller rotates -- the liquid sucked in by the inlet is simultaneously subjected to centrifugal force and axial thrust in the impeller -- the liquid flows out of the impeller at an angle -- enters the guide vane body -- the guide vane adjusts the water flow direction to axial and recovers the rotational kinetic energy -- the water flows through the outlet bend to further convert the kinetic energy into pressure energy -- and finally is discharged smoothly.

[0026] In this embodiment, the pump casing transition section is an outwardly convex arc-shaped structure, and a porous elastic wall is provided on the inner side of the pump casing transition section. A sealed gas buffer layer is provided between the pump casing transition section and the porous elastic wall.

[0027] The design method for porous elastic walls and closed gas buffer layers is as follows:

[0028] Assume a mixed-flow pump with a liquid velocity of 3 m / s, a rated flow rate of 85 m³ / s, and a head of 20 m; the liquid density is 1000. The saturated vapor pressure of the liquid is 2340 Pa.

[0029] (1) The porous elastic wall surface must meet the following requirements:

[0030]

[0031]

[0032]

[0033] Where b is the thickness of the porous wall, d is the diameter of the micropores on the porous wall, D is the diameter of the uniform section of the pump casing, Q is the rated flow rate of the mixed flow pump, and V is the flow velocity of the liquid flowing through the mixed flow pump.

[0034] When D is the diameter of the uniform section of the pump casing (6m); Q is the rated flow rate of the mixed-flow pump (85m³ / s); and V is the water flow velocity (3m / s), then b should be between 0.6mm and 6mm, and we take 1mm; d should be between 0.06mm and 3mm, and we take 0.1mm.

[0035] (2) The sealed gas buffer layer satisfies:

[0036]

[0037] in, For the gas pressure of the sealed buffer layer, V is the saturated vapor pressure of the liquid flowing through the mixed-flow pump; V is the flow velocity of the liquid flowing through the mixed-flow pump. For the rated head of the mixed-flow pump, For emptying, This is the acceleration due to gravity.

[0038] when, The Pa is 2340; V is 3 m / s; The emptying number is set to 0.3. It is 20m. but The range should be 3690Pa~196000Pa, take 100kPa.

[0039] The working principle of porous elastic walls and gas buffer layers: Pressure pulsations caused by cavitation induce deformation of the porous elastic walls, while the gas buffer layer buffers and promotes the conversion of energy into jet kinetic energy and rebound potential energy. The porous elastic walls then undergo elastic movement, thereby alleviating pressure pulsations. The porous structure not only reduces pressure pulsations and flow-induced noise but also generates velocity slip and reduces flow friction, achieving the goal of noise reduction and efficiency improvement.

[0040] After applying this design, the pressure pulsation in the dynamic-static interference zone is significantly reduced, greatly improving the efficiency of the mixed-flow pump.

[0041] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention.

Claims

1. An elastic porous housing for reducing pressure pulsation in the dynamic-static interference region of a mixed-flow pump, characterized in that, The elastic porous outer shell includes a pump casing transition section, which is the shell between the guide vane inlet and the impeller blade outlet. The pump casing transition section is the dynamic and static interference zone of the mixed flow pump. The pump casing transition section is an outwardly convex arc-shaped structure. A porous elastic wall surface is provided on the inner side of the pump casing transition section. A gas buffer layer is provided between the pump casing transition section and the porous elastic wall surface.

2. The elastic porous shell according to claim 1, characterized in that, Several micropores that do not penetrate the porous elastic wall are distributed on the porous elastic wall surface away from the abrupt change section of the pump casing. A sealed space is formed between the porous elastic wall surface and the abrupt change section of the pump casing, and the space is filled with gas as a gas buffer layer.

3. The elastic porous shell according to claim 2, characterized in that, The elastic porous outer shell also includes a uniform pump shell section, which is connected to the abrupt pump shell section. The uniform pump shell section is a shell connected to the guide vane body.

4. The elastic porous shell according to claim 3, characterized in that, The thickness of the porous elastic wall and the diameter of the micropores on the wall are: ； ； ； Where b is the thickness of the porous wall, d is the diameter of the micropores on the porous wall, D is the diameter of the uniform section of the pump casing, Q is the rated flow rate of the mixed flow pump, and V is the flow velocity of the liquid flowing through the mixed flow pump.

5. The elastic porous shell according to claim 3, characterized in that, The gas pressure of the sealed gas buffer layer is: ； in, For the gas pressure of the sealed buffer layer, V is the saturated vapor pressure of the liquid flowing through the mixed-flow pump; V is the flow velocity of the liquid flowing through the mixed-flow pump. For the rated head of the mixed-flow pump, For emptying, The density of the liquid flowing through the mixed-flow pump. This is the acceleration due to gravity.

6. The elastic porous shell according to claim 1, characterized in that, The flexible porous housing is used in guide vane mixed flow pumps.

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