Design method for changing cast guide vane into welded guide vane, welded guide vane and guide vane body

Abstract

The invention provides a design method for changing a cast guide vane into a welded guide vane. The design method comprises the following steps of calculating an average discharge section area of the cast guide vane axial surface along a flow pass, designing that the discharge section area of the welded guide vane is equal to the average discharge section area, and determining the axial surface projection of the welded guide vane according to the axial surface projection of the cast guide vane; designing that the welded guide vane comprises a first planar region, a second planar region and a cylindrical region between the first planar region and the second planar region, and under the condition of ensuring that the inlet angle, the outlet angle and the warp angle of the welded guide vane are equal to the inlet angle, the outlet angle and the warp angle of the cast guide vane, regulating the vane shape of the welded guide vane according to the vane shape of the cast guide vane. The invention also provides a welded guide vane designed by the design method and a guide vane body using the guide vane.

Description

technical field [0001] The invention relates to the field of design and manufacture of water pump guide vanes, in particular to a design method for changing a cast guide vane to a welded guide vane, a welded guide vane designed by the design method and a guide vane body using the welded guide vane. Background technique [0002] The guide vane is the energy transfer device of the water pump. Its function is to collect the liquid thrown out by the impeller, reduce the flow rate of the liquid, and convert part of the velocity energy head into the pressure energy head, and then introduce it into the next stage evenly or through diffusion. tube discharge. [0003] In order to meet the requirements of rigidity and strength, the traditional casting guide vane leaves more margin to make the blades of the guide vane relatively thicker, so it will cause a certain blocking effect in the flow channel. Moreover, the traditional casting guide vane also has the following disadvantages: du...

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Problems solved by technology

[0003] In order to meet the requirements of rigidity and strength, the traditional casting guide vane leaves more margin to make the blade of the guide vane relatively thicker, so it will cause a certain blocking effect in the flow channel

Moreover, the traditional casting guide vane also has the following disadvantages: due to the restriction of casting precision, the surface of the internal flow channel of the casting guide vane is not smooth enough, which will cause a certain hydraulic loss; the weight of the casting guide vane is relatively heavy, and more materials are required This leads to higher costs; defects such as pores, shrinkage cavities, sand holes and cracks are prone to occur during the casting process, and repairing unqualified castings will increase a lot of labor costs and material costs; dust, harmful gases and noise generated during the casting process have a negative impact on Environmental pollution is more serious than other mechanical manufacturing processes

[0005] At present, many manufacturers at home and abroad are beginning to try to change the cast guide vanes into welded guide vanes, but there are still some urgent problems to be solved in the transformation: the welded guide vanes of many manufacturers have been transformed to make the curved surface tend to be straight for the convenience of processing. Reducing the overall size, which is very different from the shape of the original casting guide vane, is equivalent to designing a completely different new guide vane model. This guide vane will cause the kinetic energy of the liquid flowing out of the impeller to be unable to be completely converted into pressure energy to a certain extent. , cannot eliminate the liquid rotation component, resulting in more energy loss and lower efficiency

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