CN103032370B - Efficient asymmetric guide blade body matched with annular pumping chamber - Google Patents

Abstract

The invention discloses an efficient asymmetric guide blade body matched with an annular pumping chamber. The guide blade body consists of blades (1) and a cover plate (2), wherein the guide blade body is installed between an impeller (3) and the annular pumping chamber (4); the blades (1) are fixed on the cover plate (2) and asymmetrically arranged in a circumferential direction; with a first blade as a starting point, in the rotating direction of the impeller, the included angle between the outlet edge of an adjacent blade and the outlet edge of a previous blade is theta, is related to the number of the blades, and is gradually increased from 2 degrees to 50 degrees; a sum of all the included angles is 3600 degrees; an optimal installing angle between a radius of the outlet edge of the first blade and an outlet central line of the annular pumping chamber is 0-150 degrees; inlet and outlet installing angles, wrap angles and other structural parameters of all the blades are the same; and the asymmetric structure is applicable to design of a cylindrical radial guide blade and a twisted spatial guide blade. The asymmetric guide blade body improves hydraulic matching performance of the impeller and the pumping chamber, thus improving the efficiency and the running stability of a pump.

Description

A high-efficiency asymmetric guide vane body matching the annular pressurized water chamber

technical field

The invention relates to a high-efficiency asymmetric guide vane body matched with an annular pressurized water chamber, belonging to the field of fluid machinery.

Background technique

The guide vane body is a device widely used in water pumps. In some water pumps, due to structural and design reasons, it is often necessary to design the pressurized water chamber into an annular structure. Due to the low matching characteristics of the annular pressurized water chamber and the impeller, the fluid in the annular pressurized water chamber produces a large hydraulic loss, resulting in The pump is less efficient. The guide vane body can collect and transport the liquid flowing from the impeller to the downstream, and convert the kinetic energy of part of the liquid flow into pressure energy, eliminating the rotation of the liquid flow and significantly improving the pump efficiency. The traditional guide vane blades adopt a structure uniformly arranged along the circumferential direction. According to the law of fluid flow, the flow out of the guide vane body along the direction of impeller rotation increases gradually. When the blades are uniformly arranged, the flow rate in each flow channel The difference will lead to uneven distribution of liquid velocity, resulting in increased hydraulic loss in the guide vane body, reducing pump efficiency, and even inducing vibration of the pump body, which will affect the stability of the pump operation. The research data also shows that the hydraulic loss in the guide vane body occupies a large proportion in the whole pump.

At present, the research on the guide vane mainly focuses on the optimization of the blade profile, geometric parameters, number of blades and other factors. Huang Hui et al. studied the influence of the outlet diameter of the guide vane body and the placement angle of the blade outlet on the matching characteristics of the impeller and the performance of the pump. Zhang Desheng et al. studied the influence of the number of guide vane blades on pump performance and pressure pulsation in a diagonal flow pump. Zhou Ling et al. conducted research on deep well pumps, and analyzed the influence of guide vanes with two different blade forms, cylindrical and twisted, on pump performance. The current research focuses on the guide vane body with blades evenly arranged along the circumference. The performance of the guide vane has not been studied from the arrangement structure of the blades, so as to further improve the efficiency of the guide vane body and the matching performance with the impeller and the pressure water chamber. Therefore, it is of practical significance to break the traditional design and reconstruct the structure of the guide vane body.

Contents of the invention

In order to improve the efficiency of the guide vane body, the present invention breaks the traditional way of uniform arrangement of blades along the circumferential direction, and proposes a guide vane body in which the blades are asymmetrically arranged along the circumferential direction.

The invention relates to a high-efficiency asymmetric guide vane body matched with an annular pressurized water chamber. The guide vane body is composed of blades and a cover plate, and the guide vane body is installed between the impeller and the annular pressurized water chamber. The blades of the guide vane body are arranged asymmetrically along the circumference, with the first blade as the starting point, along the direction of impeller rotation, the angle between the outlet edge of the adjacent blade and the outlet edge of the previous blade is θ, and the angle is related to the number of blades. Related, gradually increase by 2~5°, and the sum of all included angles is 360°. The structural parameters such as placement angle and wrap angle are the same. The asymmetric structure proposed by the present invention is applicable to the design of cylindrical radial guide vanes and twisted space guide vanes.

The advantages of the present invention are: according to the characteristic that the flow rate of the fluid on the flow section at the outlet of the guide vane body increases along the rotation direction of the water pump, the flow capacity of each flow channel is reconstructed by gradually increasing the angle between the blades, which conforms to the real flow law, The fluid velocity distribution in the guide vane body is uniform, so as to reduce the flow loss inside the pump. The asymmetric arrangement of the guide vane body improves the hydraulic matching performance of the impeller and the pressure water chamber, which can improve the efficiency and operation stability of the pump.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing.

Fig. 1 is a schematic cross-sectional view of the guide vane shaft of the asymmetric mechanism of the present invention.

Fig. 2 is an axial cross-sectional view of a conventional guide vane body with evenly arranged blades.

Detailed ways

As shown in Figure 1, after the vane body is completed according to the traditional design method, the blades are arranged asymmetrically, the blade 1 is fixed on the cover plate 2, and the vane body is installed between the impeller 3 and the annular pressure water chamber 4. When designing cylindrical radial guide vanes and twisted space guide vanes, the blades are arranged asymmetrically along the circumference, taking Figure 1 as an example: the guide vane has 11 blades, starting from the first blade, the second The angle θ between the two blades and the first blade is 22.7°, the angle between the outlet edge of the adjacent blade and the outlet edge of the previous blade increases gradually by 2°, the outlet edge of the first blade and the outlet of the annular pressurized water chamber The optimal placement angle of the center line is 15°, and the structural parameters such as placement angle and wrap angle of all blades are the same. The traditional blade layout is shown in Figure 2, using the same impeller 3 and pressure water chamber 4, and the guide vane blade 1 along the circumference Evenly arranged, the angle between adjacent blades is 32.7°. In this example, the CFD method is used to predict the performance of the pump. Under the same impeller and pressure water chamber conditions, when the asymmetric guide vane body is used, the efficiency of the pump is 1.0% higher than that of the traditional uniformly arranged guide vane body. The guide vane body is completed by precision casting technology, and the position of the guide vane body relative to the pressure water chamber is guaranteed during installation. The invention improves the distribution of the velocity field of the fluid in the guide vane body, makes the distribution of the liquid flow velocity among the flow channels of each blade uniform, reduces the hydraulic loss, and thereby achieves the purpose of reducing the flow loss inside the pump. The asymmetrically arranged guide vane body improves the impeller And the matching performance of the pressure water chamber, thereby improving the efficiency and operation stability of the pump.

Claims (1)

1., for an efficient asymmetric diffuser for the coupling annular pumping chamber in pump, this diffuser is by blade (1), and cover plate (2) forms, and diffuser is installed between impeller (3) and annular pumping chamber (4); It is characterized in that, blade is fixing on the cover board, and blade is asymmetric arrangement along the circumferential direction; With first blade for starting point, along vane rotary direction, the Exit-edge of adjacent blades and the angle of last exit edge of blade are θ, and this angle is relevant with the number of blade, by 2 ~ 5 ⁰increase gradually, and all angle sums are 360 ⁰; Vaned laying angle, cornerite structural parameter identical; Between the Exit-edge place radius of first blade and the center line of discharge of annular pumping chamber, angle is 0 ~ 15 ⁰.