Stationary blade partition plate assembly tool for impulse-stage steam turbine

Abstract

According to the assembly tool for the static blade partition plate of the impulse-stage steam turbine, a static blade is positioned in a blade runner between an outer ring body and a shroud body mounting ring through a tool, the static blade of the impulse-stage steam turbine is installed, welded and fixed through a bridging plate between the outer ring body and the shroud body mounting ring, and the positioning tool comprises a base; the base is fan-shaped and is embedded and contacted between the outer ring body and the shroud ring body, the fan-shaped base can move on a circular track formed between the outer ring body and the shroud ring body, and the base is provided with a pair of fixed short pins and mounting holes, a pair of movable short pins and mounting holes and a pair of fixed long pins and mounting holes; the installation position of one stationary blade is determined through the two short fixed pins, the two long fixed pins and the pin distance between the short fixed pins and the two long fixed pins, and after the first stationary blade is installed, the relative positions of the adjacent stationary blades are determined through the two short movable pins and an SA throat width gauge. The distance between every two adjacent static blades is calibrated through an arranged SA throat width gauge. The throat width SA is the minimum width of a channel between every two adjacent stator blades.

Description

Technical Field

[0001] The utility model relates to the technical field of static blade diaphragms, in particular to a static blade diaphragm of an impulse stage steam turbine. The utility model also relates to a manufacturing tooling for the static blade diaphragm of an impulse stage steam turbine. Background Art

[0002] The steam turbine is known as the "crown of manufacturing". The steam turbine is not only a key equipment in the energy and power industry, but also a very important equipment for China's transformation and development. Moreover, the manufacturing of steam turbines is a systematic project with quite high technical content and quality requirements.

[0003] The flow passage part of the steam turbine includes important components such as a rotor, moving blades, and a static blade diaphragm. The static blade diaphragm includes an outer ring and a shroud ring. Between the outer ring and the shroud ring are static blades with accurate dimensions and precise installation. The manufacturing precision of the static blade diaphragm directly affects the thermal efficiency of the steam turbine unit. And the static blade diaphragm bears the load generated by the pressure difference during operation. Under the action of high-temperature and high-pressure steam, there are situations of easy deformation, easy corrosion, and wear. The original processing scheme is to separately process the inner and outer ring bodies, and then determine the installation position of the static blades by means of scribing. This method has poor positioning accuracy and is difficult to control the SA throat width dimension between the blades. The SA throat width is an important blade design parameter and plays a crucial role in blade design, having an important impact on aspects such as the rotational speed, efficiency, and life of the steam turbine. If there is a deviation in the blade installation position, it may also cause uneven gaps to occur between the static blades and the ring body before welding. During the welding of the diaphragm, the gaps will cause welding deformation and other situations.

[0004] To solve the above problems, the technical solution of the utility model is to adopt combined processing of the outer ring and the shroud ring, and through a positioning tooling, improve the installation and positioning accuracy before welding the static blades and the ring body; the flow passage surface is processed with a graphene coating, so that the diaphragm has the characteristics of being ultra-thin, ultra-hard, high-temperature oxidation-resistant, corrosion-resistant, wear-resistant, and has a thermal barrier effect. Content of the Utility Model

[0005] The purpose of the utility model is to propose an assembly tooling for the static blade diaphragm of an impulse stage steam turbine. The static blades of the impulse stage steam turbine are assembled and welded by bridging between the outer ring body and the shroud body installation ring. After bridging, finish machining of the flow passage surface is carried out to accurately control the SA throat width dimension between the blades, so that this static blade diaphragm has an accurate steam outlet direction, and the flow passage throat area is controlled within a very small error range, which can meet the accuracy requirements.

[0006] The technical solution of the present utility model is an assembly tooling for the stationary blade diaphragm of an impulse-stage steam turbine. The stationary blades of the impulse-stage steam turbine are formed by butt-welding the stationary blades of the impulse-stage steam turbine between the inner ring formed by the outer ring body and the shroud body mounting ring, thereby forming the stationary blade diaphragm of the impulse-stage steam turbine; the stationary blades of the impulse-stage steam turbine are fixed by butt-welding the bridging plates between the outer ring body and the shroud body mounting ring. The stationary blades are positioned within the blade flow passage 4 between the outer ring body and the shroud body mounting ring through the tooling. The positioning tooling includes a base 5, which is fan-shaped and embedded in and contacts between the outer ring body and the shroud body. The fan-shaped base can move on the circular track formed between the outer ring body and the shroud body. A pair of fixed short pins 7 and mounting holes, a pair of movable short pins 6 and mounting holes, and a pair of fixed long pins 9 and mounting holes are provided on the base 5. The installation position of one stationary blade 3 is determined by two fixed short pins 7, two fixed long pins 9, and the pin pitch between the fixed short pin 7 and the two fixed long pins. After the installation of the first stationary blade is completed, the relative positions of the adjacent stationary blades are determined by two movable short pins 6 and an additional SA throat width gauge. The distance between adjacent stationary blades 3 is calibrated by the SA throat width gauge 8 provided; the SA throat width 8 is the minimum width of the passage between adjacent stationary blades 3.

[0007] The holes where the fixed short pins 7, fixed long pins 9, and movable short pins 6 are installed on the tooling are designed and processed according to the blade spacing of the diaphragm to ensure the blade positioning accuracy.

[0008] Beneficial effects: The stationary blades of the impulse-stage steam turbine are butt-welded by the bridging plates between the outer ring body and the shroud body. After the bridging plates, finish machining of the flow passage surface is carried out, and the stationary blades themselves are also machined. Then, through the high-precision tooling of the present utility model, the stationary blades are accurately fixed in the flow passage, accurately controlling the SA throat width size between the blades, enabling the stationary blade diaphragm to have an accurate steam outlet direction, and controlling the throat area of the flow passage within a very small error range, which can meet the accuracy requirements. Description of the Drawings

[0009] Figure 1 is a schematic structural diagram of the stationary blade diaphragm of the impulse-stage steam turbine;

[0010] Figure 2 is a schematic cross-sectional view after the outer ring 1 and the shroud ring 2 are butt-welded and fixed through the bridging plate 10;

[0011] Figure 3 is Figure 2 the top view of

[0012] Figure 4 is a schematic diagram of two blades before the installation of the tooling;

[0013] Figure 5 is a schematic cross-sectional view of the tooling installing the blades.

[0014] Figure 6 is a schematic cross-sectional view of the tooling installing two blades. Detailed implementation mode

[0015] The stationary blade diaphragm of an impulse steam turbine, which includes an outer ring body, a shroud ring body, and stationary blades. A blade flow passage is formed between the outer ring body and the shroud ring body, and the stationary blades are fixed in the blade flow passage by welding.

[0016] An assembly tooling for the stationary blade diaphragm of an impulse steam turbine. The stationary blade diaphragm includes an outer ring 1, a shroud ring 2, and stationary blades 3. The outer ring 1 and the shroud ring 2 are concentrically arranged. A blade flow passage 4 is provided between the outer ring 1 and the shroud ring 2. The blade flow passage 4 is provided with a number of stationary blades 3 evenly distributed in the circumferential direction. The outer shape of the stationary blades 3 is curved and has good streamline. The stationary blades are positioned in the blade flow passage 4 by the tooling. The positioning tooling includes a base 5. A pair of fixed short pins 7 and a pair of fixed long pins 9 are provided on the base 5. The installation position of the stationary blade 3 is determined by two fixed short pins 7 and two fixed long pins 9. It also includes movable short pins 6. The relative position of two adjacent stationary blades 3 is determined by two movable short pins 6. A throat width gauge 8 is provided between two adjacent stationary blades 3 to determine the distance between the blades. The SA throat width gauge 8 is the minimum width of the passage between two adjacent stationary blades 3. The throat width is detected using the SA throat width gauge, and the throat width dimension.

[0017] Furthermore, the holes where the fixed short pins 7, fixed long pins 9, and movable short pins 6 are located on the tooling are designed and processed according to the diaphragm model to ensure the blade positioning accuracy.

[0018] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model:

[0019] 1. Leave a combined machining allowance of 5 mm on one side for rough machining of the outer ring and the shroud ring;

[0020] 2. Adjust the flow passage width and axial dimension drop of the outer ring and the shroud ring. Group welding is carried out through 3 - 6 bridging plates 10 evenly distributed between the outer ring 1 and the shroud ring 2. The bridging plates are U-shaped plates, fixed to the bottom surfaces of the outer ring 1 and the shroud ring 2, so as not to affect the installation of the stationary blades. After the stationary blades are installed and processed, the bridging plates 10 are cut off;

[0021] 3. Precision turn the stationary blade flow passage surface;

[0022] Installation of the positioning tooling:

[0023] 4. The positioning tooling fits with the diaphragm flow passage, that is, fits with the inner arc of the outer ring and the outer circle of the shroud ring;

[0024] 4.2. Determine the position of the first stationary blade 3 with the positioning tooling in three dimensions:

[0025] 4.2.1. Positioning direction 1: The root part of the stationary blade 3 fits with the plane of the positioning tooling;

[0026] 4.2.2, Positioning direction 2: The root position of the 3 stator vanes is fitted with two fixed short pins 7;

[0027] 4.2.3, Positioning direction 3: The tip of the 3 stator vanes is fitted with two fixed long pins 2;

[0028] 5. After positioning and spot-welding the first stator vane, slide the positioning tooling on the circumferential track and insert two movable short pins 6 into the mounting holes on the positioning tooling: Make the root of the first stator vane flush with the movable short pin 6, and sequentially install the second adjacent stator vane 3, and control the pitch between adjacent stator vanes with the SA throat width gauge; The requirements are the same above, the pitch between adjacent stator vanes 3 is fixed, and the SA throat width between adjacent stator vanes 3 is guaranteed by the positioning accuracy of the tooling, then position and spot-weld the second adjacent stator vane. After removing the movable short pins and fixed short pins, move the positioning tooling and install the adjacent vanes until all the vanes in one circle are installed.

[0029] 6. After all the blade groups are welded, the surface of the blade flow path is processed with a graphene coating, so that the diaphragm has the characteristics of ultra-thin, ultra-hard, high-temperature oxidation resistance, corrosion resistance and wear resistance, and has a thermal barrier effect.

[0030] Reference Figure 6 , For the installation of double vanes and subsequent vanes, only movable short pins are needed; The first vane uses long pins, and subsequent vanes do not need to use long pins again. Remove the long and short pins after installation and welding.

[0031] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principle and purpose of the present invention.

Claims

1. An impulse-stage steam turbine stationary blade diaphragm assembly tool, characterized in that: The stator blades of the impulse stage steam turbine are welded by bridging the inner ring body formed by the outer ring body and the shroud body mounting ring, thereby forming the stator blade partition of the impulse stage steam turbine; the stator blade is positioned in the blade flow channel between the outer ring body and the shroud body mounting ring by a tool, and the stator blade of the impulse stage steam turbine is welded and fixed by bridging the outer ring body and the shroud body mounting ring. The tool includes a base, which is fan-shaped and embedded and contacted between the outer ring body and the shroud body, and the fan-shaped base can move on the circular track formed between the outer ring body and the shroud body. The base is provided with a pair of fixed short pins and mounting holes, a pair of movable short pins and mounting holes, and a pair of fixed long pins and mounting holes. The installation position of a static blade is determined by two fixed short pins, two fixed long pins, and the pin distance between the fixed short and two fixed long pins. After the first static blade is installed, the relative positions of adjacent static blades are determined by two movable short pins and an SA throat width gauge provided separately, that is, the spacing between adjacent static blades is calibrated by the SA throat width gauge provided; the SA throat width is the minimum width of the channel between adjacent static blades.

2. The impulse stage steam turbine stator blade diaphragm assembly tool according to claim 1 is characterized in that: The holes where the fixed short pins, the fixed long pins and the movable short pins installed on the tooling are located are determined according to the spacing between the partition blades.

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