Segmented hollow rotor of steam turbine
By using a three-section structural design with differentiated thermal expansion coefficient matching and overall connection, the complexity and stress concentration of the segmented hollow rotor structure of the steam turbine are solved, resulting in lower maintenance costs and faster start-up time, adapting to frequent start-up and shutdown conditions.
Patent Information
- Application Number
- CN202520800877.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-25
- Publication Date
- 2026-01-30
- Estimated Expiration
- 2035-04-25
AI Technical Summary
The structural complexity of existing segmented hollow rotors for steam turbines may increase the failure rate, and the stress concentration coefficient at the joints of multiple segments is high, making it difficult to guarantee the concentricity and runout requirements after assembly, resulting in high maintenance costs.
The three-section structure design with different thermal expansion coefficients is adopted. The rotor at the valve end, the middle section of the rotor and the rotor at the motor end are connected into a whole by connecting nuts and connecting shafts. The concentricity and runout requirements are guaranteed by end face tooth meshing and high-precision tooling. In case of local damage, the damaged section can be replaced separately.
It reduces peak thermal stress by 25%-40%, reduces maintenance costs by 60%-70%, improves adaptability and start-up time under frequent start-up and shutdown conditions, and shortens the start-up time of peak-shaving units by 30%-40%.
Smart Images
Figure CN223854322U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to steam turbine rotor processing technical field especially, it relates to sectional hollow rotor. The utility model further relates to the preparation of steam turbine sectional hollow rotor. BACKGROUND
[0002] Steam turbine is not only praised as "manufacturing industry crown", also is the core power device of modern energy equipment, and the performance of its rotor system directly determines the whole machine operation efficiency and reliability. In the field of ultra-supercritical unit and gas turbine, sectional hollow rotor is gradually replacing the traditional solid rotor structure with its unique structural advantages. This innovative structure composed of multiple hollow segments not only realizes the lightweight target of 15%-25%, but also breaks through the 700 DEG C limit of working temperature through the design of internal cooling channel.
[0003] The sectional hollow rotor of the existing steam turbine sectional hollow rotor adopts multi-section independent module combination structure, and is connected through precise welding or high-strength bolt between sections. Often inlayed with connecting shaft or pipe shaft, this design allows to adjust local mechanical parameters (such as wall thickness, diameter) for different working conditions, for example, the wall thickness of high-pressure section can reach 200 millimeters, and the wall thickness of medium and low-pressure section gradually decreases to 80 millimeters, realizing stress gradient distribution.
[0004] The sectional hollow cavity is embedded with axial-radial composite cooling channel, and the airflow path is optimized through computational fluid dynamics (CFD). The high-temperature area (such as the inlet section) of the rotor is configured with double-layer cooling interlayer, which can reduce the working temperature by 40-60 DEG C, significantly prolonging the service life of the material.
[0005] Nickel-based high-temperature alloy (such as GH4169) and titanium-aluminum composite material are combined in sections, the yield strength of high-pressure section reaches 1200 MPa, and the toughness and corrosion resistance of low-pressure section are considered.
[0006] The hollow sections of the prior art are formed by isothermal forging + numerical control spinning process, and the dimensional error is controlled within
[0007] ±0.05 millimeters. The welding joint adopts electron beam deep penetration welding, and the joint strength coefficient can reach more than 95% of the base material.
[0008] Although the sectional hollow rotor has significant advantages, there are still controversies that its structural complexity may increase the failure rate. The stress concentration coefficient of the multi-section connection still needs to be further optimized (the current minimum is 1.3, compared with 0.9 of the whole rotor).
[0009] The existing segmented hollow rotor is composed of a valve adjusting end rotor, a rotor middle segment and a motor end rotor, and the concentricity of the valve adjusting end rotor and the motor end rotor is required to be ensured within 0.02 mm, and the run-out of the shaft neck outer circle of the two side rotors is required to be ensured within 0.015 mm; a conventional processing method is to process each part of the segmented rotor separately, and this method cannot ensure the overall concentricity and run-out requirements after assembly. Practical new content
[0010] To solve the above problems, the purpose of the present application is to provide a segmented hollow rotor for steam turbine, which can adapt to frequent start-stop working conditions through matching of differential thermal expansion coefficients of different segments.
[0011] The technical scheme of the present application is a segmented hollow rotor for steam turbine, which comprises a hollow valve adjusting end rotor, a hollow rotor middle segment and a hollow motor end rotor coaxially connected in sequence to form a whole hollow rotor, the end faces of the valve adjusting end rotor and the rotor middle segment and the rotor middle segment and the motor end rotor are prepared into end face teeth, and the valve adjusting end rotor and one end of the rotor middle segment and the other end of the rotor middle segment are engaged with the motor end rotor through the end face teeth.
[0012] During preparation, connecting nuts and connecting shafts are used to connect the valve adjusting end rotor, the rotor middle segment and the motor end rotor into a whole, so that the overall combined processing of the segmented hollow rotor is realized, and the concentricity of the valve adjusting end rotor and the motor end rotor and the run-out requirements of the shaft necks of the two ends of the rotor are ensured.
[0013] Advantages: The present application is a hollow rotor with a three-segment structure, the differential thermal expansion coefficients of the segments are matched, the materials can be different, the thermal stress peak value is reduced by 25%-40%, and the segmented hollow rotor can adapt to frequent start-stop working conditions. When a segment is damaged, the damaged segment can be replaced alone, and the maintenance cost is reduced by 60%-70% compared with the overall rotor. The peak shaving unit is optimized, in the daily start-stop peak shaving unit, the rapid thermal response characteristics of the segmented hollow rotor shorten the start-up time by 30%-40%. The present application is especially applied to a million-kilowatt unit, the copper-magnetic double shielding structure at the end of the stator cooperates with the segmented hollow rotor, and the unit can maintain stable operation under 40%-110% load fluctuation. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 The final structure of the present application is shown in the figure;
[0015] Figure 2 The tool connection diagram of the present application during intermediate processing is shown in the figure, and a connecting shaft 7 is arranged in the middle during processing;
[0016] Figure 3 The 3D schematic diagram of the rotor middle segment of the present application is shown in the figure;
[0017] Figure 4 Structure diagram of pre-machining valve end rotor;
[0018] Figure 5 Structure diagram of motor end rotor;
[0019] Figure 6 Structure diagram of pre-machining valve end rotor;
[0020] Figure 7 Structure diagram of intermediate section 2. DETAILED DESCRIPTION
[0021] The technical solutions in the embodiments of the utility model will be clearly and completely described in connection with the drawings in the embodiments of the utility model:
[0022] As shown in the drawings, the segmented hollow rotor of the steam turbine comprises hollow valve end rotor, hollow intermediate section of rotor and hollow motor end rotor which are coaxially connected in sequence to form a whole hollow rotor, the end faces of the valve end rotor and the intermediate section of rotor and the intermediate section of rotor and the motor end rotor are prepared into end face teeth, and the valve end rotor and the intermediate section of rotor at one end and the intermediate section of rotor at the other end are engaged with the motor end rotor through the end face teeth.
[0023] The segmented hollow rotor of the steam turbine is manufactured, and the segmented rotor structure comprises valve end rotor, intermediate section of rotor, motor end rotor and connecting bolt; the valve end rotor is engaged with the intermediate section of rotor through end face teeth and is fixed through the connecting bolt, the intermediate section of rotor is engaged with the motor end rotor through end face teeth; the valve end rotor is internally provided with connecting nut, the connecting nut is fixed to the left end of connecting shaft through internal thread, the outer circle of the connecting shaft is transitionally matched with the intermediate section of rotor, and the right end of the connecting shaft is fixed with the motor end rotor through external thread.
[0024] The utility model discloses a high-precision tool is connected into whole by valve end rotor, intermediate section of rotor and motor end rotor, and finally realizes the whole combination processing of segmented hollow rotor, guarantees the concentricity of valve end and motor end rotor and the requirement of rotor two end journal play.
[0025] The specific steps are as follows:
[0026] 1, valve end rotor 1, intermediate section of rotor 2 and motor end rotor 3 are separately loaded on the machine, and the inner and outer circles are roughly turned and semi-precision turned;
[0027] 2, the end face teeth of valve end rotor, intermediate section of rotor and motor end rotor are milled;
[0028] The typical valve end rotor, the outer diameter of rotor Inner hole The tooth number of the rotor end face tooth 4 of the regulating valve end is 60, the tooth height is 9mm, the tooth type angle is 60°, the tooth number of the rotor end face tooth 5 of the motor end is 50, the tooth height is 7mm, and the tooth type angle is 60°;
[0029] 3. Pre-machining the inner hole of the regulating valve end rotor, Figure 6 The inner hole 8 of the regulating valve end rotor is in clearance fit with the connecting nut; the outer circle 9 of the regulating valve end rotor is in clearance fit with the middle section of the rotor;
[0030] 4. Finishing the inner hole 10 of the middle section of the rotor, Figure 7 The inner hole of the middle section of the rotor is in clearance fit with the outer circle of the regulating valve end rotor;
[0031] 5. Assembling the middle section of the rotor and the regulating valve end rotor, the end face tooth is matched, and the bolt 6 is fixed; the inner hole of the middle section of the rotor is machined, and the inner hole of the middle section of the rotor is in transition fit with the connecting shaft 7
[0032] 6. Pre-machining the inner hole of the motor end rotor, the inner hole of the motor end rotor is in clearance fit with the connecting shaft; pre-machining the inner thread of the motor end rotor, and the motor end rotor is fixed with the connecting shaft through the inner thread.
[0033] 7. Installing the connecting nut and the connecting shaft, connecting the regulating valve end rotor, the middle section of the rotor and the motor end rotor into an integral whole;
[0034] 8. Finishing the precision outer circle of the rotor;
[0035] 9. Finishing the inner hole of the regulating valve end rotor, the middle section of the rotor and the motor end rotor.
[0036] The above only describes preferred embodiments of the utility model and is not used for limiting the utility model. For those skilled in the art, the utility model can have various changes and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.
Claims
1. A steam turbine segmented hollow rotor characterized by, The hollow valve adjusting end rotor, the hollow middle rotor and the hollow motor end rotor are coaxially connected in sequence to form a whole hollow rotor, and the surfaces between the valve adjusting end rotor and the middle rotor and between the middle rotor and the motor end rotor are prepared into end face teeth.
2. A steam turbine segmented hollow rotor as claimed in claim 1, characterized in that The valve adjusting end rotor has 60 end face teeth with a tooth height of 9 mm and a tooth type angle of 60°, and the motor end rotor has 50 end face teeth with a tooth height of 7 mm and a tooth type angle of 60°.