Design method of high-efficiency submersible flow inducer

Abstract

The application provides a design method of high-efficiency submersible flow pusher, which comprises the following steps: determining the diameter D of the impeller and the axial velocity V at the disc surface according to the flow pushing distance and the flow disturbance diameter ′ ; calculating the flow at the disc surface per second and per hour and the thrust T of the impeller; preliminarily selecting the rotating speed n of the impeller; calculating the power required by the flow pushing fluid and estimating the power of the power system according to the mechanical efficiency N%; selecting a suitable power system; if the rotating speed of the power system cannot match the rotating speed n of the impeller, repeatedly modifying the rotating speed n of the impeller until the rotating speed of the impeller is the same as the rotating speed of the power system, so that the impeller and the power system can be completely matched; and finally designing and fixing the installation and fixing device. The axial velocity at the disc surface of the impeller and the thrust per unit area at the disc surface are taken as the design indexes, and the design method of the submersible flow pusher is first proposed. The submersible flow pusher designed by the method has large water flow speed and large flow pushing flow, and the power consumption is lower.

Description

Technical Field

[0001] This invention belongs to the field of submersible propeller technology, specifically relating to a design method for a high-efficiency submersible propeller. Background Technology

[0002] Submersible mixers are flow-generating devices primarily used in municipal sewage and various industrial wastewater treatment biochemical ponds, lakes, and aquaculture ponds. Early submersible mixers in my country were mostly imported products, or modified designs or blade-cuttings of foreign products. Currently, mainstream domestic submersible mixers consist of four main parts: impeller, reducer, submersible motor, and mounting bracket. The impeller is one of the core components of a submersible mixer. Existing impellers all adopt propeller technology; however, submersible mixers designed using propeller theory suffer from high power consumption, low efficiency, and wasted energy exceeding usable energy consumption. The primary function of a propeller is to generate thrust to propel a ship forward; moving water is merely a side effect, and the propulsive effect of a propeller is very weak. Therefore, propeller theory is not suitable for the design of submersible mixers. Furthermore, when designing submersible mixers using propeller theory, impeller diameter and thrust are the main design parameters, but water flow velocity is not included, although water flow velocity is one of the most critical performance characteristics of a submersible mixer.

[0003] Existing publicly available literature on submersible jet propulsion mainly focuses on the mounting method of the support, the material of the impeller, and the manufacturing method. For example, patent CN 111392882 A proposes the impeller shape for a submersible jet propulsion system, suggesting that impellers with higher blade density have better propulsion performance. However, there is currently no publicly available information on the design methodology for submersible jet propulsion systems. Summary of the Invention

[0004] This invention provides a design method for a high-efficiency submersible jet propulsion device, overcoming the current problem of the lack of a design method for a high-efficiency submersible jet propulsion device.

[0005] The design method for the high-efficiency submersible thruster provided by this invention includes the following steps in sequence:

[0006] (1) Determine the impeller diameter D, axial velocity V at the disk surface, and thrust T′ per unit disk area according to the requirements of thrust distance and turbulence diameter;

[0007] (2) Calculate the flow rate at the disk surface per second. And calculate the hourly flow rate at the disk based on the flow rate per second at the disk surface: Q = 3600Q v Calculate the thrust of the impeller.

[0008] (3) Initially select the impeller speed n, so that

[0009] (4) Calculate the power required for the propulsion fluid: P1 = Q v T′, estimate the power of the power source based on mechanical efficiency N%.

[0010] (5) Select a suitable power system. If the speed of the power system cannot match the speed n of the impeller, modify the speed n of the impeller to make the speed of the impeller the same as the speed of the power system.

[0011] (6) Repeat steps (3)-(5) until the impeller and the power system are fully matched;

[0012] (7) Design, installation and fixing devices.

[0013] Preferably, the thrust T′ per unit disk area of ​​the impeller is <25000 N / m. 2 .

[0014] Preferably, the power source can be an underwater motor or a hydraulic motor.

[0015] Preferably, the power source is an underwater motor. If the selected underwater motor has a rotational speed of 5 times or more than the impeller speed, the underwater motor is connected to the impeller through a reducer. By modifying the impeller speed n, the rotational speed of the underwater motor after reduction is made to be the same as the impeller speed n, and the power of the power source is greater than P.

[0016] Preferably, the power source is an underwater motor. If the speed of the underwater motor is less than 5 times the speed of the impeller, the underwater motor is directly connected to the impeller. By modifying the speed n of the impeller, the speed of the underwater motor is made the same as the speed n of the impeller, and the power of the power source is greater than P.

[0017] Preferably, the power source is a hydraulic motor drive, and the speed of the hydraulic motor is made the same as the speed of the impeller by modifying the speed n of the impeller, and the power of the power source is greater than P.

[0018] The beneficial effects of this invention are:

[0019] (1) The design of the submersible jet propeller mainly includes the design of the impeller and the selection of the power system. At present, there is no publicly available information in China that proposes a systematic design method for the submersible jet propeller. The only information disclosed is that the impellers of the submersible jet propeller are designed using propeller theory. The thrust and impeller diameter are the design indicators of the impeller. This patent takes the axial velocity of the impeller disk, the thrust per unit area in the disk, and the impeller diameter as design indicators, and proposes a design method for the submersible jet propeller for the first time.

[0020] (2) Other domestic submersible thrusters use thrust as a design indicator, but the thrust per unit area of ​​the impeller disk is more universally applicable. This patent uses the thrust per unit area of ​​the disk as a design indicator.

[0021] (3) Other domestic submersible jet propellers only consider the thrust and impeller diameter, without considering the water flow velocity. However, the water flow velocity is the design target of the submersible jet propeller. This invention uses the water flow velocity at the disc as the design index, and the jet propulsion effect is better than other submersible jet propellers, with a larger effective jet propulsion distance.

[0022] (4) The submersible thruster designed by the method of the present invention has a large water flow velocity and a large thrust flow rate, but lower power consumption. Detailed Implementation

[0023] To make the purpose, technical solution, and advantages of the invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and should not be construed as limiting the specific scope of protection of the invention.

[0024] The design method for the high-efficiency submersible thruster provided in this embodiment includes the following steps:

[0025] (1) Determine the impeller diameter D, axial velocity V at the disk surface, and thrust T′ per unit disk area according to the requirements of thrust distance and turbulence diameter;

[0026] (2) Calculate the flow rate at the disk surface per second. And calculate the hourly flow rate at the disk based on the flow rate per second at the disk surface: Q = 3600Q v Calculate the thrust of the impeller.

[0027] (3) Initially select the impeller speed n, so that

[0028] (4) Calculate the power required for the propulsion fluid: P1 = Q v T′, estimate the power of the power source based on mechanical efficiency N%.

[0029] (5) Select a suitable power system. If the speed of the power system cannot match the speed n of the impeller, modify the speed n of the impeller to make the speed of the impeller the same as the speed of the power system.

[0030] (6) Repeat steps (3)-(5) until the impeller and the power system are fully matched;

[0031] (7) Design, installation and fixing devices.

[0032] Example 1

[0033] (1) The impeller diameter D is 1000 mm, the axial velocity at the disk surface is V = 0.70 m / s, and the thrust per unit disk area is T′ = 305 N / m. 2 ;

[0034] (2) Flow rate per second at the disk Hourly traffic impeller thrust

[0035] (3) The impeller speed was initially selected as n = 38 rpm.

[0036] (4) Calculate the power required for the propulsion fluid: P1 = Q v T′=167W, estimate the power of the power source based on a mechanical efficiency of 65%.

[0037] (5) In this embodiment, the power system is selected as an underwater motor with a speed of 1450 rpm, a speed ratio of 30 for the reducer, a power source providing a speed of 1450 ÷ 30 = 48.3 rpm, and a motor power of 550 W;

[0038] (6) Modify the impeller design to achieve a required speed n of 48 rpm to match the power system.

[0039] (7) Design, installation and fixing devices.

[0040] Experiments show that when the flow velocity at the disk surface reaches 0.68 m / s, the maximum turbulence diameter is 3.9 m, and the effective axial flow distance (velocity greater than 0.1 m / s) exceeds 25 m. Computational fluid dynamics (CFD) simulations show a turbulence diameter of 3.95 m, an effective axial flow distance of 26 m, and a fluid volume of 7693 m³ / s or higher at a velocity greater than 0.2 m / s. 3 / h, the CFD simulation results and experimental results are in good agreement.

[0041] Example 2

[0042] (1) The impeller diameter D is 1000 mm, the axial velocity at the disk surface is V = 0.70 m / s, and the thrust per unit disk area is T′ = 1000 N / m. 2 ;

[0043] (2) Flow rate per second at the disk Hourly traffic at the trading screen impeller thrust

[0044] (3) The impeller speed n = 90 rpm was initially selected.

[0045] (4) Calculate the power required for the propulsion fluid: P1 = Q v T′=556W, estimate the power of the power source based on a mechanical efficiency of 65%.

[0046] (5) Select the pump model of the hydraulic station as CB-B6, the hydraulic motor model as BM1-80, the hydraulic motor speed as 102rpm, and the power as 1.1KW;

[0047] (6) Modify the impeller design to achieve a required speed n of 102 rpm to match the power system.

[0048] (7) Design, installation and fixing devices.

[0049] CFD simulations show that the velocity reaches over 0.55 m / s at 5 m in front of the impeller, the maximum turbulence diameter is 4.08 m, the effective axial thrust (velocity greater than 0.1 m / s) distance is over 34.8 m, and the fluid volume with a velocity greater than 0.2 m / s is 9846 m³. 3 / h.

[0050] Example 3

[0051] (1) The impeller diameter D is 580 mm, the axial velocity at the disk surface is V = 1.05 m / s, and the thrust per unit disk area is T′ = 3000 N / m. 2 ;

[0052] (2) Flow rate per second at the disk Hourly traffic at the trading screen impeller thrust

[0053] (3) The impeller speed was initially selected as n = 200 rpm.

[0054] (4) Calculate the power required for the propulsion fluid: P1 = Q v T′=833W, estimate the power of the power source based on a mechanical efficiency of 75%.

[0055] (5) The pump model of the hydraulic station selected for the power system is CB-B8, and the hydraulic motor model is BM1-50. The hydraulic motor speed is 205rpm and the power provided is 1.5KW.

[0056] (6) Modify the impeller design to achieve a required speed n of 205 rpm to match the power system.

[0057] (7) Design, installation and fixing devices.

[0058] CFD simulations show that the velocity reaches over 0.7 m / s at 5 m in front of the thruster, the maximum turbulence diameter is 4.24 m, the effective axial thrust (velocity greater than 0.1 m / s) distance is over 31.6 m, and the fluid volume with a velocity greater than 0.2 m / s is 8620 m³. 3 above.

[0059] Example 4

[0060] (1) The impeller diameter D is 500mm, the axial velocity at the disk surface is V = 1.42m / s, and the thrust per unit disk area is T′ = 6000N / m. 2 ;

[0061] (2) Flow rate per second at the disk Hourly traffic at the trading screen impeller thrust

[0062] (3) The impeller speed was initially selected as n = 400 rpm.

[0063] (4) Calculate the power required for the propulsion fluid: P1 = Q v T′=1667W, estimate the power of the power source based on a mechanical efficiency of 50%.

[0064] (5) The hydraulic station pump model is CB-B16 and the hydraulic motor model is BM1-50. The hydraulic motor speed is 410rpm and the power provided is 3.0KW.

[0065] (6) Modify the impeller design to achieve a required speed n of 410 rpm to match the power system.

[0066] (7) Design, installation and fixing devices.

[0067] CFD simulations show that the velocity reaches over 1.3 m / s at 5 m in front of the impeller, the maximum turbulence diameter is 6.0 m, the effective axial impeller distance (velocity greater than 0.1 m / s) is over 35.8 m, and the fluid volume with a velocity greater than 0.2 m / s is 20257 m³. 3 above.

[0068] Example 5

[0069] (1) The impeller diameter D is 630 mm, the axial velocity at the disk surface is V = 1.78 m / s, and the thrust per unit disk area is T′ = 9000 N / m. 2 ;

[0070] (2) Flow rate per second at the disk Hourly traffic at the trading screen impeller thrust

[0071] (3) The impeller speed was initially selected as n = 400 rpm.

[0072] (4) Calculate the power required for the propulsion fluid: P1 = Q v T′ = 5000W, estimate the power of the power source based on a mechanical efficiency of 65%.

[0073] (5) Select an underwater motor with a power of 7.5KW, 10 poles, and a speed of 550rpm;

[0074] (6) Modify the impeller design to achieve a required speed n of 550 rpm to match the power system.

[0075] (7) Design, installation and fixing devices.

[0076] CFD simulations show that the velocity reaches over 1.5 m / s 5 m in front of the thruster, the maximum turbulence diameter is 7.85 m, the effective axial thrust (water velocity greater than 0.1 m / s) distance is over 38 m, and the fluid volume with a velocity greater than 0.2 m / s is 29361 m³. 3 above.

Claims

1. A design method for a high-efficiency submersible thruster, characterized in that, The steps are as follows: (1) Determine the impeller diameter D, axial velocity V at the disk surface, and thrust per unit disk area based on the required thrust distance and turbulence diameter. ; (2) Calculate the flow rate at the disk surface per second. And calculate the hourly flow rate at the disk based on the flow rate at the disk per second. Calculate the thrust of the impeller. ; (3) Initially select the impeller speed n, so that >500; (4) Calculate the power required for the thrust fluid. Estimate the power of the power source based on mechanical efficiency N%. ; (5) Select a power system. The power system can be an underwater motor or a hydraulic motor. If the speed of the power system cannot match the speed n of the impeller, modify the speed n of the impeller so that the speed of the impeller is the same as the speed of the power system. (6) Repeat steps (3)-(5) until the impeller and the power system are fully matched; (7) Design, installation and fixing devices.

2. The design method of the high-efficiency submersible thruster according to claim 1, characterized in that: The thrust per unit disk area of ​​the impeller .

3. The design method of the high-efficiency submersible thruster according to claim 1, characterized in that: The power system uses an underwater motor. If the selected underwater motor's speed is 5 times or more than the impeller's speed, the underwater motor is connected to the impeller via a reducer. By modifying the impeller's speed n, the underwater motor's speed after reduction is made the same as the impeller's speed n, and the power of the power system is greater than P.

4. The design method of the high-efficiency submersible thruster according to claim 1, characterized in that: The power system uses an underwater motor. If the speed of the underwater motor is less than 5 times the speed of the impeller, the underwater motor is directly connected to the impeller. By modifying the speed n of the impeller, the speed of the underwater motor is made the same as the speed n of the impeller, and the power of the power system is greater than P.

5. The design method of the high-efficiency submersible thruster according to claim 1, characterized in that: The power system is driven by a hydraulic motor. By modifying the impeller speed n, the speed of the hydraulic motor is made the same as the speed of the impeller, and the power of the power system is greater than P.

Images