A blade structure and design method for a rotor

Abstract

The present invention relates to a rotor blade structure and design method, and relates to the technical field of water pumps, including a blade body, which is fixedly mounted on a rotor and close to one end of an impeller. The present invention has the advantage of being able to achieve good heat dissipation effect.

Description

Technical Field

[0001] The present application relates to the technical field of water pumps, and in particular to a blade structure and design method for a rotor. Background Art

[0002] The electronic control board inside the electronic water pump is a key component for controlling and managing the operation of the electronic water pump, which is conducive to the efficient, safe and stable operation of the electronic water pump. During the operation of the electronic water pump, the electronic components on the electronic control board will generate heat during the operation. If the temperature is too high, it will lead to performance degradation, shortened life, and even failure or damage. Summary of the invention

[0003] In view of the deficiencies in the prior art, one of the purposes of the present application is to provide a rotor blade structure and design method, which has the advantage of being able to achieve good heat dissipation effect.

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

[0005] A blade structure for a rotor comprises a blade body, wherein the blade body is fixedly mounted on the rotor and close to one end of an impeller.

[0006] In a preferred example, the present application can be further configured as follows: the blade body includes a connecting portion and a rotating blade, and the rotating blade can be a forward curved blade, a straight outlet blade or a backward curved blade.

[0007] The present application also discloses a design method for a rotor blade structure, including a flow acquisition step to obtain a design flow rate; a water head calculation step to obtain a water head H that can be reached by a water pump, and a water head loss h1 of a rear pump cavity of the water pump. ; Solving step, calculating the geometric parameters of the flow channel of the blade body; judging step, judging whether the meridian plane meets the requirements; trimming step, adjusting the blade parameters; forming step, rounding the blade head and trimming the tail.

[0008] In a preferred example, the present application can be further configured as follows: in the flow acquisition step, assuming that the electronic water pump is in operation, the thermal power of its electric control board is P, and the temperature rise control range ΔT is the maximum value ΔT max According to the definition (1), the leakage of the rear pump chamber Q can be obtained l , the definition (1) is:

[0009] (1);

[0010] In the formula, Q l is the leakage of the rear pump chamber, in m 3 / s; P is thermal power, unit is W; is the fluid density in kg / m 3 ; Cp is the specific heat capacity of the fluid, in J / (kg·℃); ΔT is the change in temperature, in K;

[0011] When the thermal power is P, ΔT is the maximum value ΔT max Under design, the density is determined according to the fluid medium transported by the electronic water pump. and specific heat capacity C p , the rear pump chamber leakage Q can be obtained by definition (1): l , which is the design flow rate.

[0012] In a preferred example, the present application can be further configured as follows: in the step of calculating the water head h, it is known that the water head that the electronic water pump can reach is H. According to the definition formula (2), the water head loss of the rear pump chamber of the electronic water pump can be obtained:

[0013] (2);

[0014] In the formula, h l is the head loss of the rear pump chamber, in m; is the loss coefficient along the way; l i is the length of the pipeline, in m; d i is the pipe diameter, in m; is the local hydraulic loss coefficient; Q l is the leakage of the rear pump chamber, in m 3 / s; g is the value of gravity acceleration, the unit is m / s 2 ; A i is the flow cross-sectional area of ​​the pipe, in m 2 , combined with the head loss of the rear pump cavity, according to the definition (3), h can be obtained.

[0015] (3);

[0016] The water head h that the blade structure needs to reach when the electronic water pump operates under the design conditions can be obtained.

[0017] This application has the following advantages:

[0018] By setting a blade structure on the rotor to increase the reflux volume of the rear pump cavity, the heat dissipation is enhanced, the temperature rise of the electronic control board is reduced, and the service life of the electronic control board is extended, so that the electronic water pump can operate safely, stably and efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the cross-sectional structure of this application.

[0020] Figure 2 This is a schematic diagram of the structure of the blade body (forward curved type) of the present application.

[0021] Figure 3 This is a sample parameter diagram for this application.

[0022] Reference numerals: 1, impeller; 2, rotor; 3, blade body; 31, rotating blade; 32, connecting part. DETAILED DESCRIPTION

[0023] The present application is further described in detail below in conjunction with the accompanying drawings.

[0024] Reference Figure 1 and Figure 2 , is a rotor blade structure disclosed in the present application, including a blade body 3, the blade body 3 is arranged on the rotor 2 and close to one end of the impeller 1, the blade body 3 includes a connecting portion 32 and a rotating blade 31, the rotating blade 31 is fixed on the connecting portion 32, the connecting portion 32 is fixed on the rotor 2, the rotating blade 31 can be a forward curved blade, a straight outlet blade or a backward curved blade. In the present embodiment, the rotating blade 31 is a forward curved blade, and the rotation speed of the rotating blade 31 is consistent with the rotation speed of the impeller 1.

[0025] The present application also discloses a method for designing a rotor blade structure, comprising the following steps: a flow acquisition step, obtaining a design flow rate; a water head calculation step, obtaining a water head H that can be reached by a water pump, obtaining a water head loss h1 in a rear pump cavity of the water pump, ; Solving step, calculate the basic geometric parameters of the blade body flow channel; judging step, judge whether the meridian plane meets the requirements; trimming step, adjust the blade parameters; forming step, round the blade head and trim the tail.

[0026] In the flow acquisition step, assume that the electronic water pump is in operation, the thermal power of its electric control board is P, and the temperature rise control range ΔT is the maximum value ΔT max According to the definition (1), the leakage of the rear pump chamber Q can be obtained l , the definition (1) is:

[0027] (1);

[0028] In the formula, Q l is the leakage of the rear pump chamber, in m 3 / s; P is thermal power, unit is W; is the fluid density in kg / m 3 ; C p is the specific heat capacity of the fluid, in J / (kg·℃); ΔT is the change in temperature, in K;

[0029] When the thermal power is P, ΔT is the maximum value ΔT max Under design, the density is determined according to the fluid medium transported by the electronic water pump. and specific heat capacity C p, the rear pump chamber leakage Q can be obtained by definition (1): l , which is the design flow rate.

[0030] In the step of calculating the water head h, it is known that the water head that the electronic water pump can reach is H. Further, according to the definition formula (2), the water head loss of the rear pump cavity of the electronic water pump can be obtained:

[0031] (2);

[0032] In the formula, h l is the head loss of the rear pump chamber, in m; is the loss coefficient along the way; l i is the length of the pipeline, in m; d i is the pipe diameter, in m; is the local hydraulic loss coefficient; Q l is the leakage of the rear pump chamber, in m 3 / s; g is the value of gravity acceleration, the unit is m / s 2 ; A i is the flow cross-sectional area of ​​the pipe, in m 2 , combined with the head loss of the rear pump cavity, according to the definition (3), h can be obtained.

[0033] (3);

[0034] The water head h that the blade structure needs to reach when the electronic water pump operates under the design conditions can be obtained.

[0035] In the solution step, the basic geometric parameters of the impeller flow channel are designed, such as the design flow rate, design head, speed, fluid density, inlet, pre-swirl state, number of blades, etc. Furthermore, CFturbo automatically solves and obtains the geometric parameters of the blade body flow channel based on the built-in empirical function.

[0036] In the judgment step, the meridian plane of the blade flow channel is set. According to the design requirements, a preliminary design result is formed to observe whether the meridian shape is relatively smooth and whether the design point is within the recommended range, to determine whether the design meets the requirements, and to make adjustments based on the specific situation. The line shape of the meridian plane is modified by the Bezier curve.

[0037] In the trimming step, a free-form surface page is used to layer the blade from the root to the tip. The curvature of the blade bending and the chord length of the blade can be controlled by dragging the control point to change the center line position. The position of the blade profile line can be controlled by changing the center point position of the blade. The thickness of the blade can also be changed by dragging the control point, and the page thickness can be modified in combination with specific data to achieve the optimal design.

[0038] In the forming step, the settings of blade head rounding and tail trimming are set. The rounding pattern is realized by adjusting the positions of Bezier curve control points on different levels and then exporting the model.

[0039] The following is an example of the parameters of a certain pump.

[0040] Assume that the electronic water pump is in operation, the thermal power of its electric control panel P = 70kW, and the temperature rise control range ΔT is the maximum value ΔT max =10K, according to the definition (1), the leakage of the rear pump chamber can be further obtained The definition formula (1) is:

[0041] (1);

[0042] At thermal power P=70kW, ΔT is the maximum value ΔT max =10K design, according to the electronic water pump to deliver the fluid medium is 50% ethylene glycol-water mixture, its density =1060kg / m 3 , specific heat capacity C P =3300 J / (kg·℃), the leakage of the rear pump chamber can be obtained by definition (1): =0.002m 3 / s, that is, the design flow rate of the blade structure is 0.002m 3 / s.

[0043] It is known that the electronic water pump can reach a water head of H = 6.27m. Further, according to the definition formula (2), the water head loss of the rear pump chamber of the electronic water pump can be obtained:

[0044] (2);

[0045] See also Figure 3 , the hydraulic structures dominated by hydraulic loss along the way in the pump body of the electronic water pump are mainly the rear cavity of the impeller cover, the rear cavity of the rotor assembly, and the shaft pores, and their effective hydraulic lengths (i.e., pipeline lengths) are 0.016m, 0.035m, and 0.015m, respectively, and their effective hydraulic diameters (i.e., pipeline diameters) are 0.03m, 0.02m, and 0.01m, respectively, and the loss coefficient along the way is is 0.03. The local loss coefficient dominated by local hydraulic loss is .

[0046] From definition (2), we can get the head loss of the rear pump cavity of the electronic water pump to be 40.72m.

[0047] Furthermore, considering the head loss of the rear pump chamber, the blade structure needs to reach a head of h. According to the definition (3), h can be obtained:

[0048] (3);

[0049] In summary, when the electronic water pump is running under the design conditions, the water head that the blade structure needs to reach is 34.45m. The blade structure on the rotor surface is designed with the help of CFturbo software.

[0050] Design the basic geometric parameters of the impeller flow channel, and the design flow rate is 0.002m 3 / h, design head is 34.45m, speed is 5000r / min, fluid density is 1060kg / m 3 , the number of blades is 4. Furthermore, CFturbo automatically solves and obtains the geometric parameters of the blade body flow channel based on the built-in empirical function.

[0051] Set the meridian plane of the blade flow channel. According to the design requirements, form a preliminary design result, observe whether the meridian shape is relatively smooth and whether the design point is within the recommended range, judge whether the design meets the requirements, and make adjustments based on the specific situation. Modify the line shape of the meridian plane through the Bezier curve.

[0052] The free-form blade is used to divide the blade from the root to the tip into 5 layers, with the hub and the rim each counted as one layer. The curvature of the blade bending and the chord length of the blade can be controlled by dragging the control point to change the center line position. The position of the blade profile line can be controlled by changing the center point position of the blade. The thickness of the blade can also be changed by dragging the control point, and the blade thickness can be modified in combination with specific data to achieve the optimal design.

[0053] The settings for rounding the blade head and trimming the tail. By adjusting the positions of the five control points of the Bezier curve on different levels, the leading and trailing edge lines of the blade are rounded and trimmed, and then the model is exported.

[0054] The implementation principle of this embodiment is: by constructing a blade structure on the rotor surface to increase the reflux volume of the rear pump chamber, strengthen heat dissipation, reduce the temperature rise of the electric control board, and extend the service life of the electric control board.

[0055] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A rotor blade structure, characterized in that: The blade body comprises a blade body, which is fixedly mounted on the rotor and close to one end of the impeller, the blade body comprises a connecting portion and a rotating blade, the connecting portion is fixedly connected to the rotor, and the central axis of the blade body is not parallel to the axis of the rotor; the blade structure is obtained by the following design method: a flow acquisition step, obtaining a design flow rate; Steps to calculate the water head h: obtain the water head H that the pump can reach, and obtain the water head loss h in the rear pump cavity of the water pump l , h=h l -H; solving step, calculating the geometric parameters of the blade body flow channel; judging step, judging whether the meridian surface meets the requirements; trimming step, adjusting the parameters of the blade body; forming step, rounding the rotating blade head and trimming the tail; in the flow acquisition step, assuming that the electronic water pump is in operation, the thermal power of its electronic control board is P, and the temperature rise control range ΔT is the maximum value ΔT max According to the definition (1), the leakage of the rear pump chamber Q can be obtained l , the definition formula (1) is: In the formula, Q l is the leakage of the rear pump chamber, in m 3 / s; P is thermal power, unit is W; ρ is fluid density, unit is kg / m 3 ; C p is the specific heat capacity of the fluid, in J / (kg·℃); ΔT is the change in temperature, in K; When the thermal power is P, ΔT is the maximum value ΔT max Under the design, the density ρ and specific heat capacity C are determined according to the fluid medium transported by the electronic water pump. p , the rear pump chamber leakage Q can be obtained by definition (1): l , that is, the design flow rate; in the step of calculating the water head h, it is known that the water head that the electronic water pump can reach is H. According to the definition formula (2), the water head loss of the rear pump chamber of the electronic water pump can be obtained: In the formula, h l is the head loss of the rear pump chamber, in m; λ is the loss coefficient along the way; l i is the length of the pipeline, in m; d i is the pipe diameter, in m; ζ i is the local hydraulic loss coefficient; Q l is the leakage of the rear pump chamber, in m 3 / s; g is the value of gravity acceleration, the unit is m / s 2 ; A i is the flow cross-sectional area of ​​the pipe, in m 2 , combined with the head loss of the pump cavity behind the pump, according to the definition formula (3), h can be obtained. h=h l -H(3); The water head h that the blade structure needs to reach when the electronic water pump operates under the design conditions can be obtained.

2. A rotor blade structure according to claim 1, characterized in that: The rotating blades can be forward curved blades, straight outlet blades or backward curved blades.

Images