Submersible pump with improved inlet flow pattern and method of regulating the same

Abstract

The application discloses a submersible pump for improving inlet flow state and a regulating method thereof, which comprises a water pump, a flow guide assembly, a control assembly and a pressure sensing assembly. The flow guide assembly is connected to the inlet section of the water pump, the control assembly is connected to the flow guide assembly and regulates the inlet direction of fluid, and the pressure sensing assembly comprises a pressure sensing device connected to the flow guide assembly and directly contacting the inlet flow field to measure the flow rate. The application utilizes two different flow guide vanes corresponding to different working conditions to eliminate the pre-rotation of the inlet flow field and prevent the generation of submerged vortex and surface vortex.

Description

Technical Field

[0001] This invention relates to the field of submersible pumps, and in particular to a submersible pump and a method for improving the inlet flow pattern. Background Technology

[0002] Submersible pumps are widely used in water conservancy projects, urban drainage, and agricultural irrigation. However, submersible pumps are quite sensitive to the inlet flow conditions. Under low flow or low water level conditions, the pre-swirl of the water flow at the inlet section can cause submerged vortices or surface vortices to be generated in the inlet flow field. The presence of these vortices will lead to a decrease in pump power, head, and efficiency, and will also increase pump noise, vibration, and hydraulic excitation force, endangering the safe operation of the pump.

[0003] Therefore, how to improve and adjust the inlet flow pattern of submersible pumps, eliminate inlet flow field pre-swirl, prevent the generation of submerged vortices and surface vortices, and thus improve the overall performance of submersible pumps under low flow conditions has become an urgent problem to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to provide a submersible pump and its adjustment method that improves the inlet flow pattern, eliminates inlet flow field pre-swirl, prevents the generation of submerged vortices and surface vortices, and improves the overall performance of the submersible pump under low flow conditions.

[0005] To achieve the above objectives, the present invention provides a submersible pump and its adjustment method for improving inlet flow, comprising a water pump, and further comprising a flow guiding component, a control component, and a pressure sensing component.

[0006] The flow guiding component is connected to the inlet section of the water pump;

[0007] The control component is connected to the flow guiding component and includes gears and a drive device to adjust the direction of the fluid inlet;

[0008] The pressure sensing component includes a pressure sensing device connected to a flow guiding component, which directly contacts the inlet flow field to measure the flow velocity.

[0009] Furthermore, the flow guiding assembly includes an electric valve, a flow guiding pipe, a flow guiding ring, and flow guiding blades;

[0010] The guide ring is installed at the inlet section of the water pump and is connected to the inlet flange by bolts;

[0011] The drainage pipeline connects the guide ring at the inlet section of the water pump to the outlet of the water pump;

[0012] The electric valve is installed on the flow guide pipe to control the flow rate within the flow guide pipe;

[0013] The guide vanes are disposed inside the guide ring.

[0014] Furthermore, the control component includes a first gear, a second gear, a third gear, and a drive device;

[0015] The first gear is connected to the guide vanes via a rotating shaft;

[0016] The drive device is connected to the third gear and drives the first gear through the second gear.

[0017] Furthermore, the pressure sensing assembly includes a pressure sensing device, a first pressure sensor, and a second pressure sensor.

[0018] The pressure sensing device is connected to the inner side of the flow guide ring and directly contacts the inlet flow field;

[0019] The first pressure sensor is located at the bottom of the pressure sensing device, perpendicular to the axis and facing the inlet flow direction;

[0020] The second pressure sensor is located on the back of the pressure sensing device, perpendicular to the flow field pre-swirl direction and facing the incoming flow.

[0021] Furthermore, the method for adjusting the submersible pump to improve the inlet flow pattern includes the following steps:

[0022] Step 1: Determine whether the import conditions are Condition 1 (complex) or Condition 2 (simple).

[0023] For operating condition 1:

[0024] Step 2: Install the guide ring with adjustable blades;

[0025] Step 3: The diversion pipeline transports the fluid from the water pump outlet to the guide ring;

[0026] Step 4: The guide ring diverts the fluid introduced from the drainage pipe to the adjustable blades;

[0027] Step 5: The pressure sensing device measures the inlet fluid pressure to obtain the angle α3 between the pre-swirl direction of the inlet flow field and the radial tangent direction, as well as the flow velocity v on the inlet plane. xy The signal is fed back to the control components and electric valves, and the measurement formula is:

[0028]

[0029] Where F is the pressure on the pressure sensor, ρ is the fluid density, A is the area of ​​the pressure sensor, g is the gravitational acceleration, and h is the water depth at the location of the pressure sensor;

[0030] The flow velocity vector measured by the pressure sensor is V z The flow velocity vector measured by the pressure sensor is V. x Under ideal conditions, the velocity vector of the flow without pre-spinning is V.t ,but

[0031]

[0032] Where Q is the pump flow rate, A p Let v be the flow area at the pump inlet, then the actual velocity vector is:

[0033] |v|=|v t |

[0034] Then there is

[0035]

[0036] α2=90°-α1

[0037] |v xy |=cosα2|v|

[0038]

[0039] Step Six: The electric valve receives the inlet planar flow velocity V xy Adjust the opening of the drainage pipe to control the flow velocity of the guide ring to be equal to or greater than the flow velocity V of the inlet flow field on the inlet plane. xy The calculation method is as follows:

[0040]

[0041] Among them, V d Q is the outlet velocity of the guide ring. d For the flow rate of the guide loop, A d The outlet area of ​​the guide ring;

[0042] Step 7: Using the guide ring with adjustable blades, the control assembly receives the process pre-swirl angle α3 from the pressure sensor, and adjusts the angle of the adjustable blades to α3 + Δα, where Δα is 5–15°; For operating condition 2:

[0043] Step 2: Install a guide ring with fixed blades for operating condition 2;

[0044] Step 3: The diversion pipeline transports the fluid from the water pump outlet to the guide ring;

[0045] Step 4: The guide ring diverts the fluid introduced from the drainage pipe to the fixed blades;

[0046] Step 5: The pressure sensor measures the inlet fluid pressure to obtain the flow velocity v on the inlet plane of the flow field. xy The signal is then fed back to the electric valve, and the measurement formula is:

[0047]

[0048] Where F is the pressure on the pressure sensor, ρ is the fluid density, A is the area of ​​the pressure sensor, g is the gravitational acceleration, and h is the water depth at the location of the pressure sensor;

[0049] The flow velocity vector measured by pressure sensor 7-1 is V z The flow velocity vector measured by pressure sensor 7-2 is V. x Under ideal conditions, the velocity vector of the flow without pre-spinning is V. t ,but

[0050]

[0051] Where Q is the pump flow rate, A p Let v be the flow area at the pump inlet, then the actual velocity vector is:

[0052] |v|=|v t |

[0053] Then there is

[0054]

[0055] α2=90°-α1

[0056] |v xy |=cosα2|v|

[0057] Step Six: The electric valve receives the flow velocity v on the inlet plane. xy Adjust the opening of the guide pipe to control the flow velocity of the guide ring to be equal to or greater than the flow velocity V of the inlet flow field on the inlet plane. xy The calculation method is as follows:

[0058]

[0059] Among them, V d Q is the outlet velocity of the guide ring. d For the flow rate of the guide loop, A d The outlet area of ​​the guide ring;

[0060] Step 7: Using a guide ring with fixed blades, set the angle of the fixed blades to between 95° and 105°;

[0061] The submersible pump structure adjustment for improving inlet flow pattern is complete. The submersible pump and its adjustment method for improving inlet flow pattern provided by this invention utilize corresponding adjustable or fixed blades to eliminate inlet flow field pre-swirl, prevent submerged vortices or surface vortices, and improve the overall performance of the submersible pump for different inlet conditions. Attached Figure Description

[0062] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0063] Figure 1 A schematic diagram of the structure of the submersible pump for improving inlet flow provided by the present invention;

[0064] Figure 2 This is a schematic diagram of the flow guiding path of the flow guiding ring in this invention;

[0065] Figure 3 This is a schematic diagram of the overall structure of the guide ring with adjustable blades in this invention;

[0066] Figure 4 This is a partial structural diagram of the guide ring with adjustable blades in this invention;

[0067] Figure 5 This is a schematic diagram of the adjustment method for the adjustable blades in this invention;

[0068] Figure 6 This is a schematic diagram of the overall structure of the guide ring with fixed blades in this invention;

[0069] Figure 7 This is a partial structural diagram of the guide ring with fixed blades in this invention;

[0070] Figure 8 This is a schematic diagram of the method for measuring flow field data using a pressure sensing device in this invention:

[0071] Figure 9 This is a schematic diagram of the adjustable blade angle adjustment in this invention;

[0072] Figure 10 This is a flowchart illustrating the adjustment process of the present invention.

[0073] Reference numerals in the attached drawings: 1. Electric valve; 2. Drainage pipe; 3. Bolt; 4. Guide ring; 4-1. Guide ring with adjustable blades; 4-2. Guide ring with fixed blades; 5. Inlet section; 5-1. Inlet flange; 6. Guide blades; 6-1. Adjustable blades; 6-2. Fixed blades; 7. Pressure sensing device; 7-1. First pressure sensor; 7-2. Second pressure sensor; 8. First gear; 9. Second gear; 10. Third gear; 11. Drive device; 12. Annular guide groove. Detailed Implementation

[0074] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0075] See Figure 1The present invention provides a submersible pump structure for improving inlet flow, comprising a flow guiding component, a control component, and a pressure sensing component. The flow guiding component, control component, and pressure sensing component are respectively mounted on the water pump. The flow guiding component is connected to the inlet section 5 of the water pump. The control component, connected to the flow guiding component, includes a gear and a drive device 11 to adjust the fluid inlet direction. The pressure sensing component, including a pressure sensing device 7 connected to the flow guiding component, directly contacts the inlet flow field to measure the flow velocity.

[0076] Specifically, the flow guiding assembly includes an electric valve 1, a flow guiding pipe 2, a flow guiding ring 4, and flow guiding vanes 6. The flow guiding pipe 2 connects the flow guiding ring 4 at the pump inlet section 5 and the pump outlet, guiding the fluid from the pump outlet into the flow guiding ring 4. When the electric valve 1 is at its maximum opening, the flow rate of the flow guiding pipe 2 does not exceed 1% of the pump's rated flow rate.

[0077] Meanwhile, electric valve 1 is installed on drainage pipe 2 to control the flow rate in drainage pipe 2.

[0078] Meanwhile, the guide ring 4 is connected to the inlet section 5, and is connected to the inlet flange 5-1 via bolts 3; see also Figure 2 The guide ring 4 has an annular guide groove 12 inside, and the adjacent guide blades 6 are slotted and connected to the annular guide groove 12 to divert the fluid introduced in the guide pipe 2 to each blade.

[0079] See Figure 4 and Figure 5 The control assembly includes a first gear 8, a second gear 9, a third gear 10, a drive unit 11, and guide vanes 6. The first gear 8 is connected to the guide vanes 6 via a rotating shaft, and the drive unit 11 is connected to the third gear 10. The second gear 9 drives the first gear 8 to adjust the opening of the guide vanes.

[0080] See Figure 4 and Figure 8 The pressure sensing assembly includes a pressure sensing device 7, a first pressure sensor 7-1, and a second pressure sensor 7-2. The pressure sensing device 7 is connected to the inner side of the guide ring and directly contacts the inlet flow field, used to measure and calculate the flow conditions of the inlet pre-swirling flow field.

[0081] The first sensor 7-1 and the second sensor 7-2 are resistance strain gauges. The first pressure sensor 7-1 is located at the bottom of the pressure sensing device 7, perpendicular to the axis and facing the inlet flow direction; the second pressure sensor 7-2 is located on the back of the pressure sensing device 7, perpendicular to the flow field pre-rotation direction and facing the inlet flow. The first sensor 7-1 and the second sensor 7-2 are used to measure the flow velocity.

[0082] The main steps for adjusting the submersible pump structure for improving inlet flow provided by this invention are as follows.

[0083] Step 1: Determine whether the pump inlet condition is Condition 1 or Condition 2.

[0084] Among them, operating condition 1 is characterized by complex inlet conditions, mainly including: ① the pump inlet is submerged at a shallow depth, and the inlet flow field is easily affected by water surface fluctuations; ② the installation environment is a natural water body, and the flow state such as flow rate and velocity changes frequently; ③ the application scenario where complex flow phenomena such as vortices and turbulence frequently occur.

[0085] Condition 2 is characterized by simple inlet conditions, mainly: ① The pump inlet is submerged at a large depth, and the inlet flow field is not easily affected by water surface fluctuations; ② The installation environment is an artificial facility such as a water storage tank, where the flow state, such as flow rate and velocity, is relatively stable; ③ It is an application scenario where complex flow phenomena such as vortices and turbulence are less likely to occur.

[0086] When the import conditions meet condition 1:

[0087] Step Two: See Figure 3 Install a guide ring 4-1 with adjustable blades 6-1.

[0088] Install the guide ring 4-1 on the inlet section 5, connect the inlet section flange 5-1 with bolts 3, and connect the drainage pipe 2.

[0089] Step 3: The diversion pipe 2 transports the fluid from the water pump outlet to the guide ring 4-1 with adjustable blades 6-1.

[0090] Step 4: The guide ring diverts the fluid introduced from the drainage pipe to the adjustable blade 6-1.

[0091] The flow guide pipe 2 guides the fluid into the flow guide ring 4-1. The annular flow guide groove 12 inside the flow guide ring 4-1 is connected to the slotted connection between the adjacent adjustable blades 6-1. The flow guide ring 4-1 diverts the introduced fluid to each adjustable blade 6-1 through the annular flow guide groove 12.

[0092] Step 5: Pressure sensor 7 measures the inlet fluid pressure, obtains flow field velocity data, and feeds the signal back to the control components and electric valve 1.

[0093] A first pressure sensor 7-1, perpendicular to the axis and facing the inlet flow direction, is installed at the bottom of the pressure sensing device 7, and a second pressure sensor 7-2, perpendicular to the flow field pre-swirl direction and facing the inlet flow, is installed at the back. The first pressure sensor 7-1 and the second sensor 7-2 measure the flow velocity, and the measurement formula is as follows:

[0094]

[0095] Where F is the pressure on the pressure sensor, ρ is the fluid density, A is the area of ​​the pressure sensor, g is the gravitational acceleration, and h is the water depth at the location of the pressure sensor;

[0096] The flow velocity vector measured by pressure sensor 7-1 is V z The flow velocity vector measured by pressure sensor 7-2 is V. x Under ideal conditions, the velocity vector of the flow without pre-spinning is V. t Then there is

[0097]

[0098] Where Q is the pump flow rate, A p Let v be the flow area at the pump inlet, then the actual velocity vector is:

[0099] |v|=|v t |

[0100] Then there is

[0101]

[0102] α2=90°-α1

[0103] |v xy |=cosα2|v|

[0104]

[0105] This yields the angle α3 between the pre-swirl direction and the radial tangent on the inlet plane, as well as the flow velocity v on the inlet plane. xy .

[0106] Step Six: Electric valve 1 receives the flow velocity v on the inlet plane. xy Adjust the opening of the drainage pipe 2 to control the flow rate of the guide ring.

[0107] Based on the flow velocity v of the inlet flow field on the inlet plane fed back by pressure sensor 7 xy Electric valve 1 will adjust the opening to control the flow rate, so that the guiding flow velocity of the guide ring 4-1 is equal to or slightly greater than the flow velocity v of the inlet flow field on the inlet plane. xy The specific calculation method is as follows:

[0108]

[0109] Among them, V d Q is the outlet velocity of the guide ring. d For the flow rate of the guide loop, A d The outlet area of ​​the guide ring.

[0110] The outlet area A of the guide ring d The design should also take into account the limitations of the above formula.

[0111] A d=2πR*H

[0112] Where R is the inner radius of the guide ring and H is the groove height of the guide ring.

[0113] Step Seven: See Figure 8 The angle of the adjustable blades 6-1 can be adjusted using the guide ring 4-1 with adjustable blades 6-1.

[0114] The adjustable blade 6-1 is connected to the first gear 8 via a rotating shaft, and the drive device 11 is connected to the third gear 10, driving the first gear 8 through the second gear 9, thereby adjusting the blade opening. The control component receives the process pre-swirl angle α3 from the pressure sensor and adjusts the angle of the adjustable blade to α3 + Δα, where Δα is 5–15°. This ensures that the guiding direction of the adjustable blade 6-1 is slightly greater than the inlet pre-swirl direction, thus counteracting the energy of the inlet pre-swirl flow field, eliminating pre-swirl, and preventing the formation of submerged vortices or surface vortices.

[0115] When the import conditions meet operating condition 2:

[0116] Step Two: See Figure 6 Install the guide ring 4-2 with fixed blades 6-2.

[0117] Install the guide ring 4-2 on the inlet section 5, connect the inlet section flange 5-1 with bolts 3, and connect the drainage pipe 2.

[0118] Step 3: The diversion pipe 2 transports the fluid from the water pump outlet to the guide ring 4-2 with fixed blades 6-2.

[0119] Step 4: The guide ring diverts the fluid introduced by the drainage pipe to the fixed blade 6-2.

[0120] The flow guide pipe 2 guides the fluid into the flow guide ring 4-2. The annular flow guide groove 12 inside the flow guide ring 4-2 is connected to the slotted connection between the adjacent adjustable blades 6-2. The flow guide ring 4-2 diverts the introduced fluid to each adjustable blade 6-2 through the annular flow guide groove 12.

[0121] Step 5: Pressure sensor 7 measures the inlet fluid pressure, obtains flow field velocity data, and feeds the signal back to the control components and electric valve 1.

[0122] A first pressure sensor 7-1, perpendicular to the axis and facing the inlet flow direction, is installed at the bottom of the pressure sensing device 7, and a second pressure sensor 7-2, perpendicular to the flow field pre-swirl direction and facing the inlet flow, is installed at the back. The first pressure sensor 7-1 and the second sensor 7-2 measure the flow velocity, and the measurement formula is as follows:

[0123]

[0124] Where F is the pressure on the pressure sensor, ρ is the fluid density, A is the area of ​​the pressure sensor, g is the gravitational acceleration, and h is the water depth at the location of the pressure sensor;

[0125] The flow velocity vector measured by pressure sensor 7-1 is V z The flow velocity vector measured by pressure sensor 7-2 is V. x Under ideal conditions, the velocity vector of the flow without pre-spinning is V. t Then there is

[0126]

[0127] Where Q is the pump flow rate, A p Let v be the flow area at the pump inlet, then the actual velocity vector is:

[0128] |v|=|v t |

[0129] Then there is

[0130]

[0131] α2=90°-α1

[0132] |v xy |=cosα2|v|

[0133] Thus, the flow velocity v on the inlet plane is obtained. xy .

[0134] Step Six: Electric valve 1 receives the flow velocity v on the inlet plane. xy Adjust the opening of the guide pipe (2) to control the flow rate of the guide ring 4-2.

[0135] Based on the flow velocity v of the inlet flow field on the inlet plane fed back by pressure sensor 7 xy Electric valve 1 will adjust the opening to control the flow rate, so that the guiding flow velocity of the guide ring 4-2 is equal to or slightly greater than the flow velocity v of the inlet flow field on the inlet plane. xy The specific calculation method is as follows:

[0136]

[0137] Among them, V d Q is the outlet velocity of the guide ring. d For the flow rate of the guide loop, A d Let A be the outlet area of ​​the guide ring. d The design should also take into account the limitations of the above formula.

[0138] A d =2πR*H

[0139] Where R is the inner radius of the guide ring and H is the groove height of the guide ring.

[0140] Step 7: Utilize the guide ring 4-2 of the fixed blade 6-2; the guide angle of the fixed blade 6-2 can be designed to be between 95° and 105°; the cross-sectional shape of the blade is streamlined, which can better exert the guiding effect and reduce energy loss.

[0141] The foregoing has shown and described 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 to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for regulating the flow state of the inlet of a submersible pump, the submersible pump comprising a pump body, further comprising a flow guide assembly connected to the inlet section (5) of the pump body, comprising a flow guide ring (4) and an electric valve (1) for regulating the flow size of the flow guide ring; a control assembly connected to the flow guide ring (4), comprising a gear (8, 9, 10) and a driving device (11) for regulating the flow direction of the inlet; a pressure sensing assembly for measuring the pressure of the inlet flow, comprising a pressure sensing device (7) for obtaining the flow velocity of the inlet flow field; the flow guide assembly comprises an electric valve (1), a flow guide pipeline (2), a flow guide ring (4), and flow guide vanes (6); the pressure sensing assembly comprises a pressure sensing device (7), a first pressure sensor (7-1) and a second pressure sensor (7-2); the pressure sensing device (7) is connected to the inner side of the flow guide ring (4) and directly contacts the inlet flow field; the first pressure sensor (7-1) is arranged at the bottom of the pressure sensing device (7) perpendicular to the shaft and faces the inlet flow direction; the second pressure sensor (7-2) is arranged at the back of the pressure sensing device (7) perpendicular to the pre-rotation direction of the flow field and faces the inlet flow; the regulating method comprises the following steps; Step 1: judging the inlet condition as working condition 1, complex inlet condition, or working condition 2, simple inlet condition; for working condition 1: Step 2: installing a flow guide ring (4-1) with adjustable vanes (6-1); Step 3: the flow guide pipeline (2) transports the fluid from the outlet of the water pump to the flow guide ring (4-1); Step 4: the flow guide ring (4) divides the fluid introduced by the flow guide pipeline into adjustable vanes (6-1); then there is for working condition 2: Step 2: installing a flow guide ring (4-2) with fixed vanes (6-2) for working condition 2; Step 3: the flow guide pipeline (2) transports the fluid from the outlet of the water pump to the flow guide ring (4-2); Step 4: the flow guide ring (4) divides the fluid introduced by the flow pipeline into fixed vanes (6-2); then there is Step 7: using the flow guide ring (4-2) with fixed vanes (6-2), setting the angle of the fixed vanes (6-2) to be between 95-105°; the structure regulation of the submersible pump for improving the inlet flow state is completed.

2. The method for regulating the flow state of the inlet of a submersible pump according to claim 1, wherein the flow guide ring (4) is arranged at the inlet section (5) of the water pump and connected to the inlet flange (5-1) by bolts (3); the flow guide pipeline (2) is connected to the flow guide ring (4) of the inlet section of the water pump and the outlet of the water pump; the electric valve (1) is arranged on the flow guide pipeline (2) to control the flow size in the flow guide pipeline; the flow guide vanes (6) are arranged in the flow guide ring (4); the control assembly comprises a first gear (8), a second gear (9), a third gear (10), and a driving device (11); the first gear (8) is connected to the flow guide vanes (6) through a rotating shaft; the driving device (11) is connected to the third gear (10) and drives the first gear (8) through the second gear (9). ​ ​ ​ ​ ​ ​ characterized in that ​ ​ ​ ​ ​ ​ Step five: the pressure sensor device (7) measures the inlet fluid pressure, and gets the angle between the pre-rotation direction of the inlet flow field and the tangential direction of the radial direction , and the flow velocity on the inlet plane , and feeds the signal back to the control assembly and the electric valve (1), and the measurement formula is: where F is the pressure experienced by the pressure sensor, where p is the fluid density, A is the pressure sensor area, g is the acceleration due to gravity, and h is the water depth at the location of the pressure sensor. The flow velocity vector measured by the first pressure sensor (7-1) is The flow velocity vector measured by the second pressure sensor (7-2) is The flow velocity vector in the ideal condition without pre-whirl is then where Q is the flow rate of the pump, A is the flow area of the water pump inlet, and V is the actual velocity vector : ​ Step six: the electric valve (1) receives the inlet plane flow rate , adjusts the flow pipe opening, controls the flow rate of the flow guide ring (4-1) to be equal to or greater than the flow rate of the inlet flow field on the inlet plane , the calculation method is: wherein, is the flow rate at the outlet of the flow ring, is the flow rate at the outlet of the flow ring, is the area of the outlet of the flow ring; Step seven: control the assembly to receive the feedback of the flow pre-rotation angle from the pressure sensing device (7) by using the flow guide ring (4-1) with adjustable blades (6-1) , adjust the angle of the adjustable blades (6-1) to , wherein, 5~15°; ​ ​ ​ ​ Step five: the pressure sensor device (7) measures the fluid pressure at the inlet, obtaining the flow rate at the inlet plane of the flow field and feeds the signal back to the electric valve (1), the measurement formula being: where F is the pressure experienced by the pressure sensor, where p is the fluid density, A is the pressure sensor area, g is the acceleration due to gravity, and h is the water depth at the location of the pressure sensor. The flow velocity vector measured by the first pressure sensor (7-1) is The flow velocity vector measured by the second pressure sensor (7-2) is The flow velocity vector in the ideal case without pre-swirl is then where Q is the flow rate of the pump, A is the flow area of the water pump inlet, and V is the actual velocity vector : ​ Step six: The electric valve (1) receives the flow rate on the inlet plane , adjusts the opening of the flow guide pipe (2), controls the flow rate of the flow guide ring (4-2) to be equal to or greater than the flow rate of the inlet flow field on the inlet plane , the calculation method is: wherein, is the flow rate at the outlet of the flow ring, is the flow rate at the outlet of the flow ring, is the area of the outlet of the flow ring; ​ ​ ​ ​ ​ ​ ​ 3. The conditioning method of an inlet flow of a submersible pump to improve the flow regime according to claim 1, wherein, ​ ​ ​

Images