A high-precision assembly and construction method for coaxial gas turbine-steam turbine generator sets

Abstract

This invention proposes a high-precision assembly and construction method for coaxial gas turbine-steam turbine generator sets, relating to the field of generator set installation. The method includes the following steps: cement block pouring using a guide channel with an anti-foaming structure; leveling of the platform and bearing seats using a multi-purpose micro-precision adjustment tool with adjusting screws; grinding of spherical bearing bushes using a limiting tool to fix the spherical bearing bushes before grinding; hoisting of large components using a self-driven hydraulic jacking tower assembly and rotatable lifting tools under single-trolley operation; shaft alignment; and shaft coupling connection using a rotor disc limiting device with a wheel alignment detection tool for shaft alignment. This application can solve the technical problems in the prior art, such as high porosity of cement blocks, insufficient shaft levelness and alignment accuracy, skewed grinding of spherical bearing bushes, and low hoisting efficiency of large components under single-trolley operation.

Description

Technical Field

[0001] This invention relates to the field of generator set installation, and more specifically, to a high-precision assembly and construction method for a coaxial gas turbine-steam turbine generator set. Background Technology

[0002] With the deepening implementation of dual-carbon goals, gas-steam combined cycle units have become core equipment in new power systems due to their advantages such as high power generation efficiency (overall efficiency exceeding 60%), low carbon emission intensity, and flexible start-up and shutdown. Among them, the 9H-class heavy-duty gas turbine has a single-cycle power output of 400MW and a combined cycle output of up to 745MW. The M701J coaxial 9H gas turbine-steam turbine combined cycle unit from Dongfang Turbine Plant represents the highest level of heavy-duty gas turbine technology in China.

[0003] However, this type of unit adopts a coaxial structure design (the gas turbine and steam turbine share the same shaft system), and its installation process faces many technical bottlenecks: First, when grouting cement blocks, traditional flow diversion methods easily cause gas to be mixed into the grout, forming surface pores, resulting in a pass rate of less than 85% and requiring repeated repairs; Second, the longitudinal lift (allowable error ≤0.02mm / m) and lateral levelness (allowable error ≤0.01mm / m) of the shaft system plate and bearing housing are difficult to control, and the traditional adjustment method using jacks and dial indicators has limited accuracy, easily leading to excessive operating vibration; Third, during the grinding of spherical bearing bushes, the lack of a precise positioning device easily leads to one-sided contact (contact area <70%), affecting the stability of the unit; Fourth, shaft alignment operations (radial deviation ≤0.03mm, axial deviation ≤0.02mm) rely on experience, with a pass rate of only about 75%. In addition, project sites often adopt a compact layout with only one overhead crane, making it difficult for traditional hoisting methods to efficiently and safely hoist large components (approximately 170 tons for the lower half of the gas turbine cylinder, approximately 170 tons for the high-pressure cylinder, and approximately 390 tons for the generator stator). Summary of the Invention

[0004] The purpose of this invention is to provide a high-precision assembly and construction method for coaxial gas turbine-steam turbine generator sets, which can solve technical problems in the prior art such as high porosity of cement pads, insufficient horizontality and alignment accuracy of shaft system, skewed grinding of spherical bearing bushes, and low hoisting efficiency of large components in single-cart scenarios.

[0005] The embodiments of the present invention are implemented as follows: This application provides a high-precision assembly and construction method for a coaxial gas turbine-steam turbine generator set, including the following steps: S1. Cement pad block pouring: A mold is set up on the foundation surface, and a guide channel with defoaming structure is used to pour grout between the platform and the foundation, and then it is cured to form a cement pad block. S2. Adjustment of the level of the platform and bearing seat: After the cement pads meet the requirements, place the platform and bearing seat on the cement pads. Use a multi-purpose micro-precision adjustment tool with the adjustment screws on the platform to adjust the longitudinal lift and lateral level of the platform and bearing seat, and then tighten the anchor bolts. S3. Spherical bearing grinding: Use a limiting tool to fix the spherical bearing in the bearing seat to limit radial displacement, and grind the spherical bearing until the contact area between the bearing and the bearing seat meets the design requirements. S4. Large component hoisting: Under single-trolley operation, a self-driven hydraulic jacking tower assembly is used in conjunction with a combined support frame and track beam, and a rotatable lifting tool is used to hoist the lower half cylinder of the gas turbine, the high-pressure cylinder module and the generator stator into place in sequence. S5. Shaft alignment: Using the low-pressure rotor as a reference, the rotor axial position is fixed by a rotor disc limiting device. With the help of a coupling alignment detection tool, the centers of each rotor are adjusted in sequence according to the coordinate data of the shaft alignment diagram to ensure that the radial and axial deviations of the coupling meet the design requirements. S6. Shaft coupling connection: After the shaft center is checked and approved, connect each coupling to both ends in sequence with the low-pressure rotor as the reference. The coupling bolts are configured according to the actual measured hole diameter, and are tightened in a symmetrical manner. The bolt elongation is used as the main control index.

[0006] Furthermore, based on the aforementioned scheme, in step S1, the water temperature is controlled at 30℃±1℃ before grouting, and the pouring speed is controlled at 0.5m. 3 / min or less; immediately after pouring, cover with moisturizing geotextile and plastic film for moisturizing and curing, and the curing period shall not be less than 3 days.

[0007] Furthermore, based on the aforementioned scheme, in step S2, a high-precision level with an accuracy of ±0.01mm / m is used to measure the elevation, and the elevation error is controlled within 0.02mm; the adjusted longitudinal elevation error is no greater than 0.02mm / m, and the lateral levelness error is no greater than 0.01mm / m.

[0008] Furthermore, based on the aforementioned scheme, in step S3, the contact area is tested with red lead every three grinding cycles during the grinding process, and the contact area between the bearing and the bearing seat after grinding is not less than 85%.

[0009] Furthermore, based on the aforementioned scheme, in step S4, the rated lifting capacity of the rotatable lifting device is not less than 500 tons, and it can achieve ±360-degree rotation; the displacement time of the generator stator is controlled within 2 hours.

[0010] Furthermore, based on the aforementioned scheme, in step S5, the disc motion error of the rotor disc motion limiting device is no greater than 0.5 degrees; when the ambient temperature fluctuation range is ±5℃, the number of disc motion limiting devices is increased to 4, and the disc motion error is reduced to within 0.3 degrees.

[0011] Furthermore, based on the aforementioned scheme, in step S5, the accuracy requirements for shaft alignment are: the radial deviation of the coupling is no greater than 0.03 mm, and the axial deviation is no greater than 0.02 mm.

[0012] Furthermore, based on the aforementioned scheme, in step S6, the coupling bolts are weighed before installation, and the weight difference between the two bolts and matching nuts that are symmetrical in the diameter direction is less than 5 grams; before connecting the coupling, temporary bolts are used to tighten and adjust the outer circle runout, and after connection, the concentricity is measured, and the difference in symmetrical positions is less than 0.025 mm.

[0013] Furthermore, based on the aforementioned scheme, in step S6, when tightening the coupling bolts, the bolt elongation is the primary control index, and the torque value is the secondary control index.

[0014] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: This application systematically solves several technical challenges in the assembly of coaxial gas turbine-steam turbine generator sets by sequentially performing six steps: cement block pouring, platform and bearing seat leveling adjustment, spherical bearing grinding, large component hoisting, shaft alignment, and shaft coupling connection. Specifically, the use of a guide channel with an anti-foaming structure during pouring significantly reduces porosity defects in the cement block; the use of a multi-purpose micro-precision adjustment tool with adjusting screws enables micron-level precise control of longitudinal lift and lateral levelness; and the use of a limiting tool to fix the spherical bearing before grinding ensures… It can prevent slippage and ensure efficient fit between the bearing shell and the bearing seat; under single-carriage operation, the use of self-driven hydraulic jacking tower and rotatable lifting tools can realize the rapid and safe positioning of large components; the use of rotor disc limit device in conjunction with wheel centering detection tool to center the shaft system can effectively suppress axial movement and temperature interference, and improve centering accuracy; finally, the bolts are configured with actual hole diameter and the coupling is connected by symmetrical fastening and elongation control method, which can ensure the reliability of connection and the stability of concentricity, thereby improving the overall assembly accuracy, shortening the construction cycle and reducing the risk of operational vibration. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating the steps of the high-precision assembly and construction method for a coaxial gas turbine-steam turbine generator set according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the cement block casting structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the high-precision adjustment tool according to an embodiment of the present invention; Figure 4 This is a top view of the limiting tool according to an embodiment of the present invention; Figure 5 This is a front view of the limiting tool according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the rotor disc motion limiting device according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the alignment of the coupling according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the hoisting process according to an embodiment of the present invention; Figure 9 This is a schematic diagram of stator lifting and translation according to an embodiment of the present invention.

[0017] Icons: 110-Guide channel bracket, 120-Guide channel body, 130-Defoaming baffle, 140-Platform, 150-Mold box, 200-High precision adjustment tool, 210-Base, 220-Adjusting screw, 230-Support ball, 300-Limiting tool, 310-Limiting beam, 320-Spherical bearing bush, 330-Spherical bearing pad, 340-Limiting assembly, 400-Rotor disc limiting device, 410-Limiting plate, 420-Adjusting assembly, 430-Weld overlay layer, 440-Bearing box. Detailed Implementation

[0018] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0019] Please refer to Figure 1 The diagram shows the steps of the high-precision assembly and construction method for a coaxial gas turbine-steam turbine generator set, including the following steps: S1. Cement pad casting: A mold 150 is set up on the foundation surface. A guide channel with a defoaming structure is used to cast grout between the platform 140 and the foundation, and the grout is cured to form a cement pad.

[0020] S2. Leveling adjustment of platform 140 and bearing seat: After the cement pad meets the requirements, place platform 140 and bearing seat on the cement pad. Use the multi-purpose micro-precision adjustment tool 200 with the adjustment screws on platform 140 to adjust the longitudinal lift and lateral level of platform 140 and bearing seat, and then tighten the anchor bolts.

[0021] S3. Grinding of spherical bearing shell 320: Using a limiting tool 300, the spherical bearing shell 320 is fixed in the bearing seat to limit radial displacement. The spherical bearing shell 320 is ground until the contact area between the bearing shell and the bearing seat meets the design requirements.

[0022] S4. Large component hoisting: Under single-trolley operation, a self-driven hydraulic jacking tower assembly is used in conjunction with a combined support frame and track beam, and a rotatable lifting tool is used to hoist the lower half cylinder of the gas turbine, the high-pressure cylinder module and the generator stator into place in sequence.

[0023] S5. Shaft alignment: Using the low-pressure rotor as a reference, the rotor axial position is fixed by a rotor disc limit device 400. With the help of the coupling alignment detection tool, the center of each rotor is adjusted in sequence according to the coordinate data of the shaft alignment diagram to ensure that the radial and axial deviations of the coupling meet the design requirements.

[0024] S6. Shaft coupling connection: After the shaft center is checked and approved, connect each coupling to both ends in sequence with the low-pressure rotor as the reference. The coupling bolts are configured according to the actual measured hole diameter, and are tightened in a symmetrical manner. The bolt elongation is used as the main control index.

[0025] In one embodiment of this application, step S1 uses a flow channel with a defoaming structure, such as... Figure 2 Its specific structure includes a guide channel support 110 and a guide channel body 120. The guide channel body 120 is fixed to the guide channel support 110 at an incline, with the inlet facing upwards and the outlet facing downwards. Multiple defoaming baffles 130 extending along the width of the channel are provided at the bottom of the channel, with a height of 12mm to 15mm. During pouring, the grout flows downwards along the channel body. When passing through the defoaming baffles 130, the air bubbles are repeatedly cut, float to the surface, and burst, thus significantly reducing the porosity inside and on the surface of the poured body. Tests have shown that using this guide channel can improve the pass rate of surface pores (diameter ≤2mm, number ≤3 / m²) on cement blocks to over 98%.

[0026] As a preferred implementation method, in step S1, the water temperature is controlled at 30℃±1℃ before pouring the grout, and the pouring speed is controlled below 0.5m³ / min. After pouring, the grout is immediately covered with a moisture-retaining geotextile and plastic film for moisture retention and curing, with a curing period of no less than 3 days. By precisely controlling the water temperature and pouring speed, the fluidity of the grout can be further optimized and air bubbles can be avoided; moisture retention and curing prevent the surface of the pad from drying and cracking, ensuring strength.

[0027] In one embodiment of this application, the multi-purpose macro high-precision adjustment tool 200 used in step S2 is, for example... Figure 3One specific structure of this tool can be found in patent CN210524954U, which mainly includes a base 210, an adjusting screw 220, and a support ball 230. Micro-height adjustment in the 0.01mm range can be achieved by rotating the adjusting screw 220. When used with a high-precision level (accuracy ±0.01mm / m) to measure elevation, the elevation error is controlled within 0.02mm; the adjusted longitudinal lift error is no greater than 0.02mm / m, and the lateral levelness error is no greater than 0.01mm / m. This tool replaces the traditional experience-based adjustment method using jacks and dial indicators, significantly improving the level accuracy of the platform 140 and bearing seats, and fundamentally reducing unit vibration problems caused by poor installation levelness.

[0028] In one embodiment of this application, the limiting tool 300 used in step S3 is specifically a spherical bearing bush 320 grinding limiting device. Figures 4-5 As shown, the device includes limiting beams 310 symmetrically arranged on both sides of the spherical bearing shell 320. The limiting beams 310 are detachably connected to the spherical bearing shell 320 (e.g., via locking bolts). The ends of the limiting beams 310 extend out of the spherical bearing shell 320 and are provided with limiting components 340. The limiting component 340 includes an adjusting screw and a brazing layer. The adjusting screw is threadedly connected to the limiting beams 310 and perpendicular to the spherical bearing shell 330. The brazing layer is disposed at one end of the adjusting screw near the spherical bearing shell 330. By rotating the adjusting screw, a small gap (e.g., not less than 0.02 mm) can be maintained between the brazing layer and both sides of the spherical bearing shell 330, thereby limiting the lateral and longitudinal sliding of the spherical bearing shell 320 during the grinding process and ensuring that the grinding trajectory strictly conforms to the curved surface of the spherical bearing shell 330. During grinding, the contact area is tested with red lead every three grinding cycles. After grinding, the contact area between the bearing and the bearing seat is no less than 85%, which is much higher than the 70% of the traditional process, effectively avoiding the problems of one-sided contact and uneven gap between the bearing and the bearing.

[0029] In one embodiment of this application, in step S4, as follows Figures 8-9 The rotatable lifting device has a rated lifting capacity of not less than 500 tons and can rotate ±360 degrees. In single-crane operation, the self-driven hydraulic jacking tower assembly, combined support frame, and track beam are first hoisted into place using the crane. Figure 8 Then, through the self-driven movement and lifting function of the jacking tower assembly, combined with the rotation and displacement of the rotatable lifting device, an integrated operation of "lifting-rotation-positioning" is achieved, such as... Figure 9 The generator stator relocation time can be controlled within 2 hours, while the traditional single-trailer solution usually takes more than 8 hours, which greatly improves the hoisting efficiency and reduces safety risks.

[0030] In one embodiment of this application, the rotor disc motion limiting device 400 used in step S5 is, for example... Figure 6As shown, one specific structure includes a limiting plate 410, an adjusting assembly 420, and a weld overlay layer 430. The limiting plate 410 is detachably connected to the bearing housing 440 of the turbine generator (e.g., via bolts). The adjusting assembly 420 is disposed on both sides of the limiting plate 410. The weld overlay layer 430 is located at the end of the adjusting assembly 420 opposite to the limiting plate 410, for contacting the two end faces of the rotor. The adjusting assembly 420 can adjust the position of the weld overlay layer 430, controlling the gap between the weld overlay layer 430 and the rotor shaft shoulder to be between 0.3mm and 0.8mm. The weld overlay layer 430 is preferably a copper brazing layer, whose hardness is lower than that of the rotor body, to avoid damage to the rotor surface from hard friction.

[0031] This device effectively prevents axial movement when the rotor is rotated, with a rotation error of no more than 0.5 degrees. When the ambient temperature fluctuates within ±5℃, for long shaft alignment, the number of rotation limit devices can be increased from 2 to 4, further reducing the rotation error to within 0.3 degrees, thus significantly reducing the impact of temperature changes on shaft alignment accuracy. Combined with a rigid coupling centering detection tool, and adjusted according to the coordinate data of the shaft alignment diagram, the radial deviation of the coupling can be no more than 0.03mm, the axial deviation no more than 0.02mm, and the alignment accuracy rate no less than 95%.

[0032] In one embodiment of this application, in step S6, the coupling bolts are weighed before installation. The weight difference between the two bolts and their matching nuts that are symmetrical in the diameter direction is less than 5 grams to ensure dynamic balance. Before connecting the coupling, temporary bolts are used to tighten and adjust the outer diameter runout. After connection, concentricity is measured, and the difference in symmetrical positions is less than 0.025 mm. Specifically, the axial adjusting screw and the radial adjusting screw (e.g., ...) are observed using an axial dial indicator and a radial dial indicator, respectively. Figure 7 For the structure (the one perpendicular to the axial screw), when the reading is 5mm, tighten the screw. Then, move the pointers of the two dial indicators to observe whether the reading remains 5mm. If the value remains unchanged, it indicates that it is securely fixed. Figure 7 As shown. This control method is more precise than simple torque control, ensuring the reliability of the coupling connection and the long-term stability of the alignment accuracy.

[0033] The above construction method is not only applicable to the Dongfang Electric M701J coaxial 9H-class gas turbine-steam turbine combined cycle unit, but can also be applied to other 9H-class units such as the GE 9HA and Siemens SGT5-9000HL models, as well as gas turbine-steam turbine combined cycle units of different capacities such as 100MW, 300MW, and 700MW, through simple adaptation (such as adjusting the size of the lifting hook, the installation hole position of the guide channel, and the shaft alignment coordinate data).

[0034] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings. This embodiment takes the installation of the Dongfang Electric M701J coaxial 9H-class gas turbine-steam turbine combined cycle power generation unit as an example, but the present invention is not limited thereto.

[0035] Basic acceptance and handling: Roughen the surface of the foundation concrete to remove chisel chips and dust, ensuring a clean surface. Mark the unit's centerline, elevation line, and shim block position lines according to the design drawings.

[0036] Cement block casting (S1): A formwork 150 is erected on the foundation surface. The formwork 150 is made of steel template, and the joints are sealed to prevent grout leakage. A flow channel with a defoaming structure is used. The flow channel body 120 is inclined at a 45° angle, and six equidistant triangular defoaming strips are set at the bottom of the channel, with a spacing of about 100mm and a height of 12-15mm. The flow channel is divided into sections with a length of 0.8m, which can be quickly assembled according to the foundation size.

[0037] The grouting material used is MF-870G high-strength, non-shrink grouting material. Heat the purified water to 30±1℃ (use a sunshade and cooling circulation device in summer, and an insulation jacket and electric heating device in winter). Use a forced mixer, first add 80% of the water, then add all the grouting material, mix for 2-3 minutes, then add the remaining 20% ​​of the water and continue mixing until homogeneous. Control the pouring speed to below 0.5 m³ / min, continuously pouring the grouting material into the 150mm mold box through a guide channel to avoid layered pouring (to prevent cold joints). Immediately after pouring, cover with a moisture-retaining geotextile and plastic film, and maintain a curing period of no less than 3 days, watering twice daily, once in the morning and once in the afternoon, to keep the surface moist.

[0038] After curing, remove the formwork 150 and check the surface pores of the cement blocks: the pass rate of those with diameter ≤2mm and number ≤3 / ㎡ can reach over 98%.

[0039] Leveling adjustment of plate 140 and bearing housing (S2): The platform 140 and bearing housing were placed on the cured cement pad. The elevation of each bearing housing and platform 140 was measured using a high-precision level with an accuracy of ±0.01mm / m, and compared with the elevation required by the shaft alignment diagram. The error was controlled within 0.02mm.

[0040] A multi-purpose, high-precision micro-adjustment tool 200, along with the adjusting screws on the platform 140, was used to adjust the longitudinal lift and lateral levelness of the platform 140. During adjustment, the tool was placed between the platform 140 and the cement block, and slight adjustments were made by rotating the adjusting screw 220, while simultaneously monitoring the results with a frame level. After adjustment, the longitudinal lift error was ≤0.02mm / m, and the lateral levelness error was ≤0.01mm / m. The anchor bolts were then tightened to complete the fixation of the platform 140.

[0041] Spherical bearing bush 320 grinding (S3): The spherical bearing bush 320 is placed inside the bearing seat. A grinding and limiting device is used to fix the bearing bush 320: two limiting beams 310 are symmetrically fixed to both sides of the spherical bearing bush 320 with locking bolts, with the ends of the limiting beams 310 extending out of the bearing bush. The adjusting screw is rotated to maintain a 0.02–0.05 mm gap between the copper solder layer at its end and both sides of the spherical bearing pad 330. The spherical bearing bush 320 is then ground. The contact area is checked using red lead dye every three grinding passes until the contact area is not less than 85%. During the grinding process, the limiting device effectively prevents the bearing bush from sliding and deviating, ensuring precise contact between the grinding trajectory and the curved surface of the bearing pad.

[0042] Large component hoisting (S4): Only one overhead crane was available on site (rated lifting capacity of approximately 200 tons, insufficient to directly lift the 390-ton stator). A self-driven 800-ton hydraulic jacking tower assembly was used in conjunction with a modular support frame and track beam, utilizing a rotatable lifting device (rated lifting capacity of 500 tons, ±360-degree rotation). The specific operation was as follows: First, the overhead crane was used to hoist the jacking tower assembly, support frame, and track beam to the predetermined position and assemble them; then, the rotatable lifting device was connected to the generator stator, and the jacking tower assembly lifted the stator to a height exceeding the foundation height. Then, through self-drive movement, the stator was moved horizontally along the track beam to the installation position. Finally, the orientation was adjusted by rotating the lifting device, and the stator was lowered into place. Figures 8-9 As shown. The lower half cylinder (170 tons) and high-pressure cylinder module (170 tons) of the gas turbine are also hoisted in this way. The generator stator relocation time is controlled within 2 hours.

[0043] Shaft alignment (S5): Using a low-pressure rotor as a reference, the rotor rotation limiting device 400 is first installed: the limiting plate 410 is fixed to the horizontal split surface of the bearing housing 440 with bolts, and the adjusting bolt is rotated to make the gap between the copper solder layer and the rotor shaft shoulder 0.3-0.8mm. This device effectively limits the axial movement of the rotor during rotation, with a rotation error ≤0.5 degrees. When the ambient temperature changes significantly (±5℃), four limiting devices are installed on both sides of the rotor, and the rotation error can be reduced to within 0.3 degrees.

[0044] Using a rigid coupling centering test tool, and following the coordinate data in the shaft alignment diagram, the centers of the medium and low-pressure rotors, the low-pressure generator rotor, and the gas turbine-high-medium-pressure rotor were adjusted sequentially. Dial indicators and feeler gauges were used for measurement, and shim thickness was adjusted. Ultimately, the radial deviation of each coupling was ≤0.03mm, the axial deviation was ≤0.02mm, and the alignment accuracy rate was ≥95%.

[0045] Shaft coupling connection (S6): After the coupling center is inspected and found to be qualified, the coupling is connected. Connecting proceeds sequentially from the low-pressure rotor to both ends. The coupling bolts are machined hole-by-hole according to the measured hole diameter. Before installation, they are weighed using a balance; the weight difference between two bolts and nuts symmetrical in the diameter direction should be less than 5 grams.

[0046] First, tighten temporary bolts to adjust the outer diameter runout of the coupling to meet requirements. Then, replace with permanent bolts and tighten in stages using an electric hydraulic torque wrench in a symmetrical manner. Specifically, observe the readings of the axial and radial adjusting screws using axial and radial dial indicators respectively. When both readings are 5mm, tighten the screws. Afterward, move the pointers of both dial indicators to observe whether the readings remain at 5mm. If the values ​​remain unchanged, it indicates that the coupling is securely fixed. During the tightening process, bolt elongation is the main control indicator (measure the original length and the length after tightening with a micrometer; the elongation must meet the manufacturer's requirements). After tightening, based on the safe recommended value for bolt elongation, measure the bolt length with a micrometer and compare it with the original value to ensure that the elongation after tightening meets the manufacturer's technical requirements. After connection, re-measure concentricity; the difference in symmetrical positions should be less than 0.025mm.

[0047] Subsequent processes: The standard procedures include diaphragm center adjustment, steam seal gap measurement, flow clearance adjustment, cylinder cover installation, secondary grouting of the foundation, and curing. The secondary grouting process follows the requirements for pouring and curing cement pads in S1.

[0048] The beneficial effects of the embodiments of this application are as follows: By using a flow channel with an anti-foaming structure, along with optimized water temperature, pouring speed, and curing process, the surface porosity qualification rate of cement blocks was increased from below 85% to over 98%, avoiding construction delays caused by porosity repair. A multi-purpose micro-precision adjustment tool 200, in conjunction with a high-precision level, controlled longitudinal lift error to within 0.02mm / m and lateral levelness error to within 0.01mm / m, fundamentally reducing vibration problems caused by poor installation levelness. A limiting tool 300 was used to fix the spherical bearing 320, preventing slippage and deviation during grinding, increasing the contact area from less than 70% to over 85%, ensuring normal bearing self-aligning function. A self-driven hydraulic jacking tower assembly, combined with a rotatable lifting device, enabled rapid relocation of large components, reducing generator stator relocation time from over 8 hours to less than 2 hours, while also improving safety. By using a rotor disc-shifting limit device 400 to reduce axial movement and temperature interference, and in conjunction with specialized alignment tools, the radial deviation of the coupling is reduced to ≤0.03mm and the axial deviation to ≤0.02mm, increasing the alignment accuracy rate from 75% to over 95%. This method and its supporting tools are applicable to various models and capacity levels of gas turbine-steam turbine combined cycle units, demonstrating significant value for industrial promotion and application.

[0049] Furthermore, unless otherwise explicitly specified or limited, the terms "installation" and "connection" in this application embodiment should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. The terms "upper," "lower," "left," "right," "inner," "outer," and "side," etc., are merely for reference to the direction in the accompanying drawings or the usual placement of the product during use. They are only for clearly describing this application and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limitations on this application. The terms "first," "second," etc., are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance; "multiple" refers to at least two. In this application embodiment, the limitations on relative positional relationships such as parallel, perpendicular, and aligned are all relative to the current technological level and are not absolutely strict limitations. Slight deviations are allowed; approximations of parallel, perpendicular, and aligned are all acceptable. For example, "A and B are parallel" means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 degrees and 10 degrees.

[0050] The above are only some embodiments and implementation methods of this application. The protection scope of this application is not limited thereto. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. Any combination of features in different embodiments is also within the protection scope of this application. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application.

Claims

1. A high-precision assembly and construction method for a coaxial gas turbine-steam turbine generator set, characterized in that, Includes the following steps: S1. Cement pad block pouring: A mold is set up on the foundation surface, and a guide channel with defoaming structure is used to pour grout between the platform and the foundation, and then it is cured to form a cement pad block. S2. Adjustment of the level of the platform and bearing seat: After the cement pads meet the requirements, place the platform and bearing seat on the cement pads. Use a multi-purpose micro-precision adjustment tool with the adjustment screws on the platform to adjust the longitudinal lift and lateral level of the platform and bearing seat, and then tighten the anchor bolts. S3. Spherical bearing shell grinding: Use a limiting tool to fix the spherical bearing shell in the bearing seat to limit radial displacement, and grind the spherical bearing shell until the contact area between the bearing shell and the bearing seat meets the design requirements; S4. Large component hoisting: Under single-trolley operation, a self-driven hydraulic jacking tower assembly is used in conjunction with a combined support frame and track beam, and a rotatable lifting tool is used to hoist the lower half cylinder of the gas turbine, the high-pressure cylinder module and the generator stator into place in sequence. S5. Shaft alignment: Using the low-pressure rotor as a reference, the rotor axial position is fixed by a rotor disc limiting device. With the help of a coupling alignment detection tool, the centers of each rotor are adjusted in sequence according to the coordinate data of the shaft alignment diagram to ensure that the radial and axial deviations of the coupling meet the design requirements. S6. Shaft coupling connection: After the shaft center is checked and approved, connect each coupling to both ends in sequence with the low-pressure rotor as the reference. The coupling bolts are configured according to the actual measured hole diameter, and are tightened in a symmetrical manner. The bolt elongation is used as the main control index.

2. The high-precision assembly and construction method for coaxial gas turbine-steam turbine generator sets according to claim 1, characterized in that, In step S1, the water temperature is controlled at 30℃±1℃ before grouting, and the pouring speed is controlled at 0.5m. 3 / min or less; immediately after pouring, cover with moisturizing geotextile and plastic film for moisturizing and curing, and the curing period shall not be less than 3 days.

3. The high-precision assembly and construction method for coaxial gas turbine-steam turbine generator sets according to claim 2, characterized in that, In step S2, a high-precision level with an accuracy of ±0.01mm / m is used to measure the elevation, and the elevation error is controlled within 0.02mm; the adjusted longitudinal elevation error is no greater than 0.02mm / m, and the lateral levelness error is no greater than 0.01mm / m.

4. The high-precision assembly and construction method for coaxial gas turbine-steam turbine generator sets according to claim 3, characterized in that, In step S3, the contact area is checked with red lead every three grinding cycles during the grinding process, and the contact area between the bearing and the bearing seat after grinding is not less than 85%.

5. The high-precision assembly and construction method for coaxial gas turbine-steam turbine generator sets according to claim 1, characterized in that, In step S4, the rated lifting capacity of the rotatable lifting device is not less than 500 tons, and it can achieve ±360-degree rotation; the displacement time of the generator stator is controlled within 2 hours.

6. The high-precision assembly and construction method for coaxial gas turbine-steam turbine generator sets according to claim 1, characterized in that, In step S5, the disc motion error of the rotor disc motion limiting device is no greater than 0.5 degrees; when the ambient temperature fluctuates within ±5℃, the number of disc motion limiting devices is increased to 4, and the disc motion error is reduced to within 0.3 degrees.

7. The high-precision assembly and construction method for coaxial gas turbine-steam turbine generator sets according to claim 2, characterized in that, In step S5, the accuracy requirements for shaft alignment are: the radial deviation of the coupling is no greater than 0.03 mm, and the axial deviation is no greater than 0.02 mm.

8. The high-precision assembly and construction method for coaxial gas turbine-steam turbine generator sets according to any one of claims 1-7, characterized in that, In step S6, the coupling bolts are weighed before installation, and the weight difference between the two bolts and matching nuts that are symmetrical in the diameter direction is less than 5 grams; before connecting the coupling, temporary bolts are used to tighten and adjust the outer circle runout, and after connection, the concentricity is measured, and the difference in symmetrical position is less than 0.025 mm.

9. The high-precision assembly and construction method for coaxial gas turbine-steam turbine generator sets according to claim 8, characterized in that, In step S6, when tightening the coupling bolts, the bolt elongation is the main control index, and the torque value is the secondary control index.

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