A method for manufacturing a water pump turbine seat ring with an inserted guide vane welding structure

Abstract

The present invention discloses a method for manufacturing a seat ring of a water pump turbine with an inserted guide vane welding structure. It belongs to the field of water pump turbines. The present invention has an upper ring plate and a lower ring plate which are cut and welded in blocks, and then the guide vane installation welding holes are finely cut twice. The I-shaped inserted guide vane is integrally provided with a square end and a round root and is independently prepared and processed. The guide vane prepared in a single piece is inserted into the guide vane installation welding holes of the upper ring plate and the lower ring plate, and the weld between the square end of the I-shaped inserted guide vane and the ring plate is completed on the non-flow side of the upper ring plate and the lower ring plate. The cut-off area where the guide vane round root intersects with the installation welding hole is complemented by surfacing welding. The present invention greatly improves the manufacturing processability of the seat ring product, is not limited by the opening height of the seat ring product and the spatial accessibility of the guide vane flow channel length, is easy to apply the automated welding method, and enables the seat ring connection weld to avoid the high stress area of ​​the seat ring operation, thereby improving the manufacturing quality of the seat ring product and the safety margin of operation.

Description

Technical Field

[0001] The invention relates to the field of water pump turbines, and in particular to a method for manufacturing a seat ring of a water pump turbine with an inserted guide vane welding structure. Background Art

[0002] The high stress area of ​​the pump turbine seat ring and the pump seat ring is located at the circular root of the seat ring guide vane. The stress amplitude decreases from the circular root to the seat ring plate and the guide vane. The stress ratio of the center line of the seat ring water guide mechanism is △σ / △σmax<0.5. The traditional welded structure of the pump turbine seat ring and the pump seat ring adopts the T-joint welding form of the seat ring plate and the guide vane. Its disadvantages are:

[0003] 1) The connecting weld is located at the root of the guide vane circle. The high stress part of the seat ring and the weld connection part are highly overlapped. The residual stress of the weld is superimposed on the operating stress and acts on the weak link inside the weld, which brings risks to the safe and stable operation of the components.

[0004] 2) For water pump turbine seat rings and water pump seat rings with small opening heights and long flow channel dimensions, the manufacturing processability is poor, and some weld areas cannot be welded, ground, or non-destructively tested.

[0005] 3) The seat ring plate and the guide vane need to be welded and ground, which takes a long time. The surface quality of the root weld flow area and the dimensional accuracy of the ground profile are difficult to guarantee.

[0006] 4) The welding form and position between the seat ring plate and the guide vane are T-joints at the horizontal welding position and the flat fillet welding position, which are more difficult to weld than the horizontal butt joints at the flat welding position.

[0007] 5) The guide vanes and ring plates need to be assembled high and the Z-axis welding shrinkage is large, making it difficult to ensure hydraulic dimensions such as the seat ring opening height.

[0008] In summary, the pump-turbine seat ring and pump seat ring using traditional welding structure and manufacturing method have poor manufacturing processability, welding quality and dimensional accuracy are difficult to control, and the safety margin of component manufacturing and operation is relatively low. Therefore, it is necessary to develop a manufacturing method for a pump-turbine seat ring with an inserted guide vane welding structure. Summary of the invention

[0009] In view of this, the present invention adopts a new method for manufacturing a pump-turbine seat ring with an inserted guide vane welding structure, which can replace the pump-turbine seat ring and the pump seat ring with a traditional welding structure and manufacturing method, improve the manufacturing process of the seat ring product, and enhance the manufacturing quality and operation safety margin of the seat ring product; the present invention is achieved by the following steps:

[0010] Step 1: After the upper ring plate and the lower ring plate are cut and welded in blocks, the guide vane installation welding holes are cut twice, and the I-shaped inserted guide vanes are integrally provided with square ends and round roots and are independently prepared and processed;

[0011] Step 2: The I-shaped insert guide vane prepared in a single piece is inserted into the guide vane installation welding holes of the upper ring plate and the lower ring plate, and the weld between the square end of the I-shaped insert guide vane and the ring plate is completed on the non-flow side of the upper ring plate and the lower ring plate, and the cut-off area where the I-shaped insert guide vane circle root intersects with the installation welding hole is welded;

[0012] In the above-mentioned method for manufacturing a pump turbine seat ring with an inserted guide vane welded structure, in step one, when the thickness of the I-shaped inserted guide vane is less than or equal to 350 mm, the I-shaped inserted guide vane is made of tear-resistant steel plate with Z-direction performance, and when the thickness of the I-shaped inserted guide vane is greater than 350 mm, the I-shaped inserted guide vane is made of forged steel.

[0013] In the above-mentioned method for manufacturing a pump turbine seat ring with an inserted guide vane welding structure, in step one, the thickness of the square end head integrally provided with the I-shaped inserted guide vane is consistent with that of the ring plate, and the outer contour is formed by the welding groove width of the ring plate guide vane welding hole being offset outward.

[0014] In the above-mentioned method for manufacturing a pump turbine seat ring with an inserted guide vane welded structure, in step one, the round root integrally provided with the I-shaped inserted guide vane is formed by single-piece machining or grinding of the guide vane base material, and there is no need to form the round root by welding, adding material and grinding after the guide vane and the ring plate are assembled.

[0015] In the above-mentioned method for manufacturing a pump turbine seat ring with an inserted guide vane welded structure, in step 2, the welding groove between the I-shaped insert and the ring plate is a type II narrow gap groove, the welding form is a full penetration weld with a gasket on the flow side, and the welding position is a flat welding position.

[0016] In the above-mentioned method for manufacturing the seat ring of a water pump turbine with an inserted guide vane welded structure, in the step 2, if the thickness of the I-shaped inserted guide vane steel plate is limited so that the round root cannot be covered, a portion of the round root parent material is cut off along the intersection line of the guide vane P surface and the welding hole, and after the I-shaped inserted guide vane and the ring plate are assembled, the round root is supplemented by surfacing welding at the open and implementable position of the seat ring.

[0017] In the above-mentioned method for manufacturing the seat ring of a pump turbine with an inserted guide vane welded structure, in the step 2, the welding of the square end of the I-shaped inserted guide vane and the ring plate is completed on the non-flow side of the upper ring plate and the lower ring plate, and the applicable seat ring product is not limited by the opening height and the spatial accessibility of the guide vane flow channel length.

[0018] In the above-mentioned method for manufacturing a pump turbine seat ring with an inserted guide vane welded structure, in step 2, the weld between the square end of the I-shaped inserted guide vane and the ring plate is located within the thickness range of the ring plate, but not at the circular root of the guide vane.

[0019] The beneficial effects of the present invention compared with the prior art are:

[0020] 1. The present invention enables the seat ring connection weld to avoid the high stress area of ​​the seat ring operation, thereby improving the manufacturing quality of the seat ring product and the safety margin of operation.

[0021] 2. The present invention completes the welding of the square end of the I-shaped inserted guide vane and the ring plate on the non-flow side of the upper ring plate and the lower ring plate. The applicable seat ring products are not limited by the opening height and the spatial accessibility of the guide vane flow channel length, which greatly improves the manufacturing processability of the seat ring products.

[0022] 3. The circular root of the present invention is integrated with the I-shaped inserted guide vane and is formed by single-piece processing or grinding. There is no need to form the circular root by welding and adding materials and grinding after the guide vane and the ring plate are assembled. The surface quality and profile size accuracy of the flow channel area are higher, which is beneficial to enhancing the cavitation resistance of the circular root area under high water flow rate.

[0023] 4. The present invention reduces the welding difficulty and better ensures the welding quality by optimizing the welding form and welding position.

[0024] 5. The present invention optimizes the welding joint form between the ring plate and the guide vane, reduces the Z-axis welding shrinkage, and better ensures the hydraulic dimensions of the seat ring opening height. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Prepare a drawing for a single piece of I-shaped inserted guide vane.

[0026] Figure 2 This is a schematic diagram of the secondary precision cutting of the guide vane welding holes on the ring plate.

[0027] Figure 3 This is a schematic diagram of the guide vane insertion.

[0028] Figure 4 This is a cross-sectional view of the welding of guide vanes and ring plates.

[0029] Description of the components in the figure: 1-I-shaped inserted guide vane round root; 2-square end; 3-guide vane welding hole; 4-upper ring plate; 5-lower ring plate; 6-traditional welded structure guide vane; 7-I-shaped inserted guide vane; 8-welding round root; 9-welding groove between I-shaped inserted guide vane and ring plate; 10-guide vane P surface. DETAILED DESCRIPTION

[0030] The present application is further described below in conjunction with the accompanying drawings.

[0031] Specific implementation method 1: A method for manufacturing a pump turbine seat ring with an inserted guide vane welding structure provided in this implementation is implemented by the following steps:

[0032] Step 1: If Figure 1 and Figure 2 As shown, the upper ring plate 4 and the lower ring plate 5 are cut and welded in blocks, and then the guide vane welding holes 3 are finely cut for a second time. The I-shaped inserted guide vane 7 is integrally provided with a square end head 2 and a round root 1, and is independently prepared and processed. In this step, the I-shaped inserted guide vane 7 is integrally provided with a square end head 2 and a round root 1, and is independently prepared and processed. Its function is that there is no need to form a round root 8 by welding and grinding after the guide vane 6 and the ring plate are assembled. The surface quality and the profile size accuracy of the flow channel area are higher, which is beneficial to enhancing the cavitation resistance of the round root area under the action of higher water flow rates.

[0033] Step 2: If Figure 3 and Figure 4 As shown, the single-piece prepared I-shaped insert guide vane 7 is inserted into the guide vane installation welding hole 3 of the upper ring plate 4 and the lower ring plate 5, and the welding of the square end 2 of the I-shaped insert guide vane 7 and the ring plate is completed on the non-flow-through side of the upper ring plate 4 and the lower ring plate 5, and the cut-off area where the round root 1 of the I-shaped insert guide vane 7 intersects with the installation welding hole 3 is welded and supplemented; in this step, the welding of the square end 2 of the I-shaped insert guide vane 7 and the ring plate is completed on the non-flow-through side of the upper ring plate 4 and the lower ring plate 5, which serves to improve the manufacturing processability of the seat ring product, and is not limited by the opening height of the seat ring product and the spatial accessibility of the guide vane flow channel length.

[0034] Specific implementation method 2: Figure 1 and Figure 2 As shown, this embodiment further limits step 1 described in specific embodiment 1. In this embodiment, in step 1, when the thickness of the I-shaped inserted guide vane 7 is less than or equal to 350 mm, the I-shaped inserted guide vane 7 is made of tear-resistant steel plate with Z-direction performance, and when the thickness of the I-shaped inserted guide vane 7 is greater than 350 mm, the I-shaped inserted guide vane 7 is made of forged steel. Its function is to reduce the cost by selecting steel plate material when the thickness of the guide vane 7 does not exceed the allowable value, and to ensure the performance of the material of the thick guide vane 7 by using forged steel when the thickness of the guide vane 7 exceeds the allowable value; the thickness of the square end head 2 integrally provided with the I-shaped inserted guide vane 7 is consistent with that of the ring plate, and the outer contour is formed by the width of the welding groove 9 of the ring plate guide vane mounting welding hole 3 being offset outwardly, and its function is to ensure full penetration of the weld between the I-shaped inserted guide vane 7 and the ring plate and uniformity of the size of the welding groove 9 between the I-shaped inserted guide vane 7 and the ring plate, so as to facilitate the application of automated welding methods and ensure welding quality.

[0035] Specific implementation method three: Figure 3 and Figure 4As shown, this embodiment further limits step 2 described in specific embodiment 1. In this embodiment, in step 2, the welding groove 9 between the I-shaped inserted guide vane 7 and the ring plate is a II-type narrow gap groove, and the welding form is a full penetration weld with a gasket on the flow side. Its function is to optimize the welding position, reduce the welding difficulty, better ensure the welding quality, reduce the Z-direction welding shrinkage, and better ensure the hydraulic size of the seat ring opening height; if it is limited by the thickness of the steel plate of the I-shaped inserted guide vane 7 and cannot cover the circular root 1, the guide vane P surface 10 along the installation A portion of the parent material of the circular root 1 is cut off at the intersection of the welding hole 3. After the I-shaped inserted guide vane 7 is assembled with the ring plate, the circular root 1 is supplemented by surfacing welding at the open and implementable position of the seat ring. Its function is to reduce the thickness of the I-shaped inserted guide vane 7 by partially surfacing the circular root 1, so as to improve the material utilization rate of the I-shaped inserted guide vane 7; the weld between the square end 2 of the I-shaped inserted guide vane 7 and the ring plate is located within the thickness range of the ring plate, not at the circular root 8 of the guide vane 6, so that the seat ring connection weld avoids the high stress area of ​​the seat ring operation, thereby improving the manufacturing quality of the seat ring product and the safety margin of operation.

Claims

1. A method for manufacturing a pump turbine seat ring with an inserted guide vane welding structure. Features: The method is implemented by the following steps: Step 1: After the upper ring plate (4) and the lower ring plate (5) are cut into pieces and welded, the guide vane installation welding hole (3) is finely cut for a second time. The I-shaped inserted guide vane (7) is integrally provided with a square end head (2) and a round root (1) and is independently prepared and processed. The thickness of the square end head (2) is consistent with that of the ring plate, and the outer contour is formed by the width of the welding groove (9) of the ring plate guide vane installation welding hole (3) being offset outward. The round root (1) is formed by single-piece processing or grinding of the parent material of the I-shaped inserted guide vane (7), and there is no need to form the round root by welding and grinding after the guide vane and the ring plate are assembled; Step 2: The I-shaped insert guide vane (7) prepared in a single piece is inserted into the guide vane installation welding hole (3) of the upper ring plate (4) and the lower ring plate (5), and the square end (2) of the I-shaped insert guide vane (7) is welded to the ring plate on the non-flow side of the upper ring plate (4) and the lower ring plate (5). The welding groove (9) between the I-shaped insert guide vane (7) and the ring plate is a II-type narrow gap groove, and the welding form is a full penetration weld with a gasket on the flow side. The welding position is a flat welding position, and the intersection of the guide vane round root (1) and the installation welding hole (3) is welded to fill the cut-off area.

2. A method for manufacturing a pump turbine seat ring with an inserted guide vane welding structure according to claim 1, Features: In the step 1, when the thickness of the I-shaped insert guide vane (7) is less than or equal to 350 mm, the I-shaped insert guide vane (7) is made of tear-resistant steel plate with Z-direction performance; when the thickness of the I-shaped insert guide vane (7) is greater than 350 mm, the I-shaped insert guide vane (7) is made of forged steel.

3. A method for manufacturing a pump turbine seat ring with an inserted guide vane welding structure according to claim 1, Features: In the second step, if the thickness of the steel plate of the I-shaped inserted guide vane (7) is limited so that the round root (1) cannot be covered, a portion of the parent material of the round root (1) is cut off along the intersection line with the welding hole (3) on the guide vane P surface (10), and after the I-shaped inserted guide vane (7) is assembled with the ring plate, the round root (1) is supplemented by surfacing welding at the open position of the seat ring.

4. A method for manufacturing a pump turbine seat ring with an inserted guide vane welding structure according to claim 1, Features: In the step 2, the weld between the square end (2) of the I-shaped inserted guide vane (7) and the ring plate is located within the thickness range of the ring plate and not at the circular root of the guide vane.

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