Impeller and centrifugal pump having the same

Abstract

A kind of impeller, including first cover plate, second cover plate and multiple arc-shaped blades between the first cover plate and second cover plate, the middle part of the first cover plate forms hollow water inlet cavity, edge forms outlet end, the second cover plate can be connected with rotor, characterized by the blade includes main blade and interval arrangement of shunt blade, the inner end of the main blade is close to the inner ring of first cover plate, the outer end is close to the outer edge of first cover plate, the outer end of the shunt blade is close to the outer edge of first cover plate.This application discloses a kind of centrifugal pump.Add shunt blade, the increase of overall blade number can increase water pressure, and will not produce the effect of blockage at inlet;The shunt blade can also produce force on the fluid in the second half, change the flow direction and flow in more ideal direction, thereby increasing the work capacity as a whole, and then the lift of the corresponding centrifugal pump is increased.

Description

Technical Field

[0001] This invention relates to a liquid conveying device, and more particularly to an impeller for use in a water pump. The invention also relates to a water pump with an impeller. Background Technology

[0002] The zero-cold-water function of a gas water heater allows users to have hot water immediately upon turning on the tap, but this requires a water pump to circulate the water and heat the cold water in the heating element. Additionally, some users experience low water flow and pressure, necessitating the use of a water pump to increase the water flow. Therefore, the performance of the water pump plays a crucial role in the comfort of hot water usage for users.

[0003] Existing water heaters generally use centrifugal pumps, which include a pump body, an impeller mounted on the rotor of the pump body, and a volute surrounding the impeller. The volute has an inlet port corresponding to the central cavity and an outlet port for receiving water from the impeller's outlet. Figure 8 and Figure 9 As shown, the impeller 2 includes a first cover plate 21, a second cover plate 22, and a plurality of arc-shaped blades 23 disposed between the first cover plate 21 and the second cover plate 22. The middle part of the first cover plate 21 forms a hollow water inlet cavity 2a, and the edge forms a water outlet end 2b. The blades 23 are all uniformly arranged in the circumferential direction, and each blade 23 has the same length and angle, and the liquid flow rate of each flow channel is the same.

[0004] Currently, the main method to improve the performance of water pumps is to increase the pump power. Therefore, how to improve the pump efficiency and head while maintaining the power is an important research topic for those skilled in the art. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to provide an impeller that can improve work efficiency in view of the above-mentioned technical status.

[0006] The second technical problem to be solved by the present invention is to provide a centrifugal pump that can improve work efficiency.

[0007] The technical solution adopted by the present invention to solve the first technical problem mentioned above is as follows: an impeller, including a first cover plate, a second cover plate and a plurality of arc-shaped blades disposed between the first cover plate and the second cover plate, wherein the first cover plate is provided with a water inlet and the edges of the first cover plate and the second cover plate form a water outlet, wherein the blades include main blades and spaced-apart diverter blades, the inner end of the main blades is close to the inner ring of the first cover plate and the outer end is close to the outer edge of the first cover plate, and the outer end of the diverter blades is close to the outer edge of the first cover plate;

[0008] The aforementioned main blade (231) satisfies the following conditions:

[0009] The position of the point on the arc of the main blade's blade profile is given by the equation θ1=A(r / R2–R3 / R2). B To determine this, the value range of parameter A is 80 to 95, and the value range of parameter B is 0.5 to 0.7.

[0010] The arc of the main blade is represented by polar coordinates, with the projection point of the impeller rotation axis on the XY plane as the pole O, the line connecting the pole O and the point on the arc of the main blade as the polar axis r, and θ1 representing the polar angle of the point on the arc of the main blade.

[0011] The radius of the inner edge point of the arc in the main blade is R3, the outer diameter of the impeller is R2, and the ratio of R3 to R2 is in the range of 0.3 to 0.5. The radius of the outer edge point of the arc in the main blade is R4, and the ratio of R4 to R2 is 0.9 to 1.0.

[0012] The aforementioned splitter blades satisfy the following conditions:

[0013] The mid-arc of the splitter blade is generated by rotating part of the mid-arc of the main blade around the circumference by an angle θ2. The radius of the inner edge point of the mid-arc of the splitter blade is R5, and the radius of the outer edge point of the mid-arc of the main blade is R6. The ratio of R5 to diameter R2 ranges from 0.6 to 0.8, and the ratio of R6 to R2 ranges from 0.9 to 1.0.

[0014] Angle θ3 is the angle formed by the intersection of the arc with radius R5 centered at pole O and the arc of the blade profile of the two adjacent blades with the line connecting pole O. The ratio of angle θ2 to angle θ3 ranges from 0.4 to 0.6.

[0015] Preferably, the ratio of R3 to R2 is in the range of 0.38 to 0.44.

[0016] Preferably, the ratio of R4 to R2 is 0.98.

[0017] Preferably, the value range of parameter A is 82.5 to 91.5.

[0018] Preferably, the value of parameter B is in the range of 0.55 to 0.65.

[0019] Preferably, the ratio of R5 to diameter R2 is in the range of 0.67 to 0.72.

[0020] Preferably, the ratio of R6 to diameter R2 is in the range of 0.95 to 0.98.

[0021] Preferably, the ratio of angle θ2 to angle θ3 is in the range of 0.48 to 0.53.

[0022] Preferably, the main blade and the splitter blade are of equal thickness, the thickness of the main blade is h1, the thickness of the splitter blade is h2, and the ratio of h1 to h2 is in the range of 0.4 to 0.7.

[0023] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: a centrifugal pump, characterized in that it includes a pump body, an impeller disposed on the rotor of the pump body, and a volute disposed on the outer periphery of the impeller, the volute having an inlet port corresponding to the inlet and an outlet port for receiving the water outlet of the impeller.

[0024] Preferably, for ease of manufacturing and improved strength, the second cover plate of the impeller is integral with the rotor, with one side of the blade fixed to the first cover plate and the other side detachably connected to the second cover plate. Of course, the second cover plate and the rotor can also be connected separately.

[0025] Compared with existing technologies, the advantages of this invention are as follows: This invention adds diverting blades, increasing the overall number of blades and thus increasing water pressure. Since the diverting blades are only located in the rear half of the main blades, the water flow area at the impeller inlet is not reduced, preventing blockage. Simultaneously, the outer edge of the main blades is generally in the diffusion section, prone to flow separation and reduced impeller work capacity. Adding diverting blades effectively divides the flow channel in two in the rear half of the main blades, reducing diffusion and suppressing flow separation, thus ensuring work capacity. The diverting blades also exert force on the fluid in the rear half, altering its flow direction to a more ideal direction, thereby increasing overall work capacity and consequently increasing the head of the centrifugal pump.

[0026] The length and tilt angle of the main blade and the splitter blade have been further optimized. In the comparison of the velocity cloud map of the cross-section impeller domain, it can be seen that the low-speed zone of the main blade working surface has basically disappeared, and the jet zone at the outlet has also basically disappeared. The low-speed zone of the original main blade working surface has shifted to the back of the splitter blade and the previous main blade, and the velocity at the leading edge of the back of the main blade has decreased.

[0027] The comparison of velocity contour maps in the volute region shows a significant increase in the outlet velocity of the splitter blades, which is converted into pressure energy within the volute region. At the volute outlet, the low-velocity region decreases, and the velocity gradient weakens. The splitter blades increase the impeller outlet velocity and make its circumferential distribution more uniform, thus reducing the velocity gradient inside the volute to some extent. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of an embodiment.

[0029] Figure 2 for Figure 1 Partially exploded diagram.

[0030] Figure 3 for Figure 2 Exploded view of the intermediate impeller.

[0031] Figure 4 for Figure 3 A magnified view of the middle section of the impeller from another perspective.

[0032] Figure 5 This is a schematic diagram of the impeller in polar coordinates.

[0033] Figure 6 Diagram illustrating the parameters of the main blade.

[0034] Figure 7 This is a diagram illustrating the parameters of the splitter blades.

[0035] Figure 8 This is a schematic diagram of an impeller structure in the prior art.

[0036] Figure 9 This is a schematic diagram of a portion of the impeller structure from another perspective in the prior art.

[0037] Figure 10 A schematic diagram of blade parameters in existing technology Figure 1 .

[0038] Figure 11 A schematic diagram of blade parameters in existing technology Figure 2 .

[0039] Figure 12 A schematic diagram of blade parameters in existing technology Figure 3 .

[0040] Figure 13 The image shows the velocity contour plot of the impeller domain in Comparative Example 1.

[0041] Figure 14 The image shows the velocity contour plot of the impeller domain in Comparative Example 2.

[0042] Figure 15 The velocity contour plot of the impeller domain in the example is shown.

[0043] Figure 16 The image shows the velocity contour plot of the volute domain in Comparative Example 1.

[0044] Figure 17 The velocity contour plot of the volute domain in Comparative Example 2 is shown.

[0045] Figure 18 Velocity contour plot of the cross-section volute domain in the embodiment Detailed Implementation

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0047] like Figure 1, Figure 2 and Figure 3 As shown, the centrifugal pump in this embodiment includes a pump body 1, an impeller 2, and a volute 3 disposed on the outer periphery of the impeller 2. The impeller 2 is disposed on the rotor 11 of the pump body 1.

[0048] In this embodiment, the impeller 2 includes a first cover plate 21, a second cover plate 22, and a plurality of arc-shaped blades 23 disposed between the first cover plate 21 and the second cover plate 22. The first cover plate 21 has a water inlet 2a, and a water outlet 2b is formed between the edges of the first cover plate 21 and the second cover plate 22. The second cover plate 22 can be connected to the rotor 11. The second cover plate 22 of the impeller 2 is integral with the rotor 11. One side of the blades 23 is fixed to the first cover plate 21, and the other side is detachably connected to the second cover plate 22.

[0049] The volute 3 has an inlet port 31 corresponding to the central cavity and an outlet port 32 for receiving the water from the outlet of the impeller 2. The volute 3 is sealed to the pump body 1 by a screw 4.

[0050] Combination Figures 4-7 As shown, the blade 23 in this embodiment includes a main blade 231 and spaced-apart diverter blades 232. The inner end of the main blade 231 is close to the inner ring of the first cover plate 21, and the outer end is close to the outer edge of the first cover plate 21. The outer end of the diverter blade 232 is close to the outer edge of the first cover plate 21.

[0051] The main blade 231 satisfies the following conditions:

[0052] The position of the point on the arc of the main blade 231 is given by the equation θ1=A(r / R2–R3 / R2). B Therefore, the value range for parameter A is determined to be 80–95, with 82.5–91.5 being the preferred value.

[0053] The value range of parameter B is 0.5 to 0.7, with 0.55 to 0.65 being the preferred value.

[0054] The arc of the main blade 231 is represented by polar coordinates. The projection point of the impeller 2 rotation axis on the XY plane is taken as the pole O. The line connecting the pole O and the point on the arc of the main blade is the polar axis r. θ1 represents the polar angle of the point on the arc of the main blade. The rotation direction of the impeller 2 is opposite to the direction of polar angle expansion.

[0055] The radius of the inner edge point of the arc in the main blade is R3, the outer diameter of impeller 2 is R2, and the ratio of R3 to R2 is in the range of 0.3 to 0.5, with 0.38 to 0.44 being preferred.

[0056] The radius of the outer edge point of the arc in the main blade is R4, and the ratio of R4 to R2 is 0.9 to 1.0; in this embodiment, it is 0.98.

[0057] The flow divider blade 232 satisfies the following conditions:

[0058] The mid-arc of the splitter blade 232 is generated by rotating a portion of the mid-arc of the main blade 231 circumferentially by an angle θ2. The radius of the inner edge of the mid-arc of the splitter blade is R5, and the radius of the outer edge of the mid-arc of the main blade is R6. The ratio of R5 to radius R2 is preferably 0.6–0.8, with 0.67–0.72 being preferred. The ratio of R6 to R2 is preferably 0.9–1.0, with 0.95–0.98 being preferred. Angle θ3 is the angle formed by the line connecting the intersection of the arc of the blade with radius R5 centered at the pole O and the mid-arc of the blades of the two adjacent blades 23 to the pole O. The ratio of angle θ2 to angle θ3 is preferably 0.4–0.6, with 0.48–0.53 being preferred.

[0059] Both the main blade 231 and the splitter blade 232 have the same thickness. The thickness of the main blade 231 is h1, and the thickness of the splitter blade 232 is h2. The ratio of h1 to h2 is in the range of 0.4 to 0.7.

[0060] like Figure 8 , Figure 9 and Figure 10 As shown, the impeller parameters in this embodiment are as follows: the inner diameter of the central cavity R1 is 7.5 mm, the outer diameter of the impeller R2 is 21 mm, R3 is 8.8 mm, R4 is 20.5 mm, θ1 is 38.7°, R5 is 14.3 mm, R6 is 20.1 mm, θ2 is 51.4°, and θ3 is 25.7°.

[0061] Comparative Example 1, such as Figures 8-12 As shown, the impeller in this embodiment includes a first cover plate 21, a second cover plate 22, and a plurality of arc-shaped blades 23 disposed between the first cover plate 21 and the second cover plate 22. The middle part of the first cover plate 21 forms a hollow water inlet cavity 2a, and the edge forms a water outlet end 2b. The blades 23 in this embodiment are of equal length.

[0062] In this embodiment, the inner diameter of the central cavity R1 is 7.5 mm, the outer diameter of the impeller R2 is 21 mm, the working surface of the blade consists of two arc segments, R7 and R8, with R7 being 15 mm and R8 being 15.3 mm. The back surface of the blade consists of three arc segments, R9, R10 and R11, with R9 being 3.8 mm, R10 being 14.7 mm and R11 being 13.5 mm. The straight segment m on the back surface of the blade is 1.4 mm, and the corresponding central angle is 40°.

[0063] Comparative Example 2: In this embodiment, the impeller blades do not have diversion blades, only main blades. For other structures and parameters, please refer to Example 1.

[0064] The experimental analysis is as follows:

[0065] refer to Figure 13As shown, this is a cross-sectional velocity contour plot of the impeller domain in Comparative Example 1.

[0066] refer to Figure 14 The figure shows the velocity contour plot of the impeller domain in Comparative Example 2. After optimizing the main blade, the jet region and wake region at the outlet are reduced. However, due to the increased head of the optimized scheme, the blade load is increased, thus increasing the low-velocity region on the blade working surface and the flow velocity on the back of the blade.

[0067] refer to Figure 15 The figure shows the velocity contour plot of the impeller domain in the embodiment. It can be seen that after adding the splitter blade, the low-velocity region of the main blade's working surface essentially disappears, and the jet region at the outlet also essentially disappears. The low-velocity region of the original main blade's working surface shifts towards the back of the splitter blade and the previous main blade, and the velocity at the leading edge of the back of the main blade decreases.

[0068] refer to Figure 16 As shown, this is a velocity contour plot of the cross-section volute domain in Comparative Example 1.

[0069] refer to Figure 17 The figure shows the velocity contour plot of the volute domain in Comparative Example 2. It can be seen that after blade optimization, the exit velocity increases significantly and is converted into pressure energy within the volute domain. At the volute exit, the low-speed region of the optimized blade design is reduced, and the velocity gradient weakens.

[0070] refer to Figure 18 The figure shows a velocity contour plot of the volute region in the embodiment. It can be seen that the splitter blades increase the impeller exit velocity and make the circumferential distribution of the impeller exit velocity more uniform, thus reducing the velocity gradient inside the volute to some extent.

[0071] Conclusion: This embodiment is equivalent to increasing the number of blades. However, simply increasing the number of blades directly reduces the flow area of ​​a single channel. When the number of blades increases significantly, although the pressure increases, the flow rate decreases drastically. Adding splitter blades, because they are only located in the rear half of the original blades, will not cause blockage at the inlet. Furthermore, since the trailing edge of long blades is generally in the diffuser section, flow separation is prone to occur, reducing the impeller's work capacity (pressure). Adding splitter blades is equivalent to dividing the flow channel in two in the rear half of the original blades, reducing its diffuser degree and suppressing flow separation. Simultaneously, the splitter blades can exert force on the fluid in the rear half, changing its flow direction to a more ideal direction, thereby increasing its overall work capacity and thus increasing the head.

[0072] Taking a 60W pump as an example, the head in Comparative Example 1 is 13m, and the head can be increased to 15m after adopting the improved impeller in this embodiment.

Claims

1. An impeller comprising a first cover plate (21), a second cover plate (22), and a plurality of arc-shaped blades (23) disposed between the first cover plate (21) and the second cover plate (22), wherein the first cover plate (21) is provided with an inlet (2a), and an outlet end (2b) is formed between the edges of the first cover plate (21) and the second cover plate (22), characterized in that... The blade (23) includes a main blade (231) and spaced-apart diverter blades (232). The inner end of the main blade (231) is close to the inner ring of the first cover plate (21), and the outer end is close to the outer edge of the first cover plate (21). The outer end of the diverter blade (232) is close to the outer edge of the first cover plate (21). The aforementioned main blade (231) satisfies the following conditions: The position of the point on the arc of the main blade (231) is determined by the equation θ1=A(r / R2–R3 / R2). B To determine this, the value range of parameter A is 80 to 95, and the value range of parameter B is 0.5 to 0.

7. The main blade (231) is represented by polar coordinates. The projection point of the impeller (2) rotation axis on the XY plane is taken as the pole O. The line connecting the pole O and the point on the main blade is the polar axis r. θ1 represents the polar angle of the point on the main blade. The radius of the inner edge point of the arc in the main blade is R3, the outer diameter of the impeller (2) is R2, the ratio of R3 to R2 is 0.3 to 0.5, the radius of the outer edge point of the arc in the main blade is R4, and the ratio of R4 to R2 is 0.9 to 1.

0. The aforementioned splitter blade (232) satisfies the following conditions: The mid-arc of the splitter blade (232) is generated by rotating part of the mid-arc of the main blade (231) around the circumference by an angle θ2. The radius of the inner edge point of the mid-arc of the splitter blade is R5, and the radius of the outer edge point of the mid-arc of the main blade is R6. The ratio of R5 to diameter R2 is in the range of 0.6 to 0.8, and the ratio of R6 to R2 is in the range of 0.9 to 1.

0. Angle θ3 is the angle formed by the intersection of the arc with radius R5 centered at pole O and the arc of the blade profile of the two adjacent blades (23) with the line connecting pole O. The ratio of angle θ2 to angle θ3 is in the range of 0.4 to 0.

6.

2. The impeller according to claim 1, characterized in that... The ratio of R3 to R2 ranges from 0.38 to 0.

44.

3. The impeller according to claim 1, characterized in that... The ratio of R4 to R2 is 0.

98.

4. The impeller according to claim 1, characterized in that... The value range of parameter A is 82.5 to 91.

5.

5. The impeller according to claim 1, characterized in that... The value range of parameter B is 0.55 to 0.

65.

6. The impeller according to claim 1, characterized in that... The ratio of R5 to diameter R2 ranges from 0.67 to 0.

72.

7. The impeller according to claim 1, characterized in that... The ratio of R6 to diameter R2 ranges from 0.95 to 0.

98.

8. The impeller according to claim 1, characterized in that... The ratio of angle θ2 to angle θ3 ranges from 0.48 to 0.

53.

9. The impeller according to claim 1, characterized in that... The main blade (231) and the diverter blade (232) are of equal thickness. The thickness of the main blade (231) is h1, and the thickness of the diverter blade (232) is h2. The ratio of h1 to h2 is in the range of 0.4 to 0.

7.

10. A centrifugal pump having an impeller as described in any one of claims 1 to 9, characterized in that... It includes a pump body (1), an impeller (2) on a rotor (11) of the pump body (1) and a volute (3) on the outer periphery of the impeller (2). The volute (3) has an inlet port (31) corresponding to the inlet (2a) and an outlet port (32) for receiving the water outlet of the impeller (2).

11. The centrifugal pump according to claim 10, characterized in that... The second cover plate (22) of the impeller (2) is an integral part of the rotor (11). One side of the blade (23) is fixed on the first cover plate (21), and the other side is detachably connected to the second cover plate (22).

Images