Multi-stage integrated rotor structure of light-weight turbine power generation all-in-one machine

Abstract

The invention relates to the technical field of turbine power generation, and discloses a multi-stage integrated rotor structure of a lightweight turbine power generation all-in-one machine, which comprises a cantilever shaft, a bearing pack, an embedded piezoelectric actuator, a gas compressor rotor and a turbine rotor, the cantilever shaft is connected to the shaft end of a power generator, the embedded piezoelectric actuator is circumferentially arranged in a non-bearing area of the cantilever shaft, and the gas compressor rotor is arranged in the bearing pack. The bearing set is erected on the cantilever shaft, the turbine rotor is coaxially installed at one end of the cantilever shaft, the turbine shaft sleeve is arranged at the tail end of the turbine rotor, the compressor rotor is arranged on the turbine shaft sleeve in a sleeved mode, a sliding cavity is formed in the back of an impeller of the press rotor, and the tuned mass damper is arranged in the sliding cavity. And the tuned mass damper is in telecommunication connection with the embedded piezoelectric actuator. The weight of the rotor is remarkably reduced and the structural rigidity is enhanced through a composite lightweight structure and an integrated forming process, and vibration transmission and modal resonance under high-speed rotation are effectively suppressed by combining active magnetic suspension regulation and a multi-stage passive vibration suppression mechanism.

Description

Technical Field

[0001] The present invention relates to the field of turbine power generation, and more specifically, to a multi-stage integrated rotor structure of a lightweight turbine power generation integrated machine. Background Art

[0002] The rotor design of existing turbine generator sets usually adopts a relatively rigid and heavy structure, which is prone to generate large vibrations at high speeds, resulting in reduced system efficiency and affecting the stability and lifespan of the equipment.

[0003] The traditional rotor design cannot balance rotor lightweight and structural stability at high speeds, and there is an urgent need for a new design solution to solve this problem. Summary of the Invention

[0004] The present invention provides a multi-stage integrated rotor structure of a lightweight turbine power generation integrated machine, which solves the technical problem that the traditional rotor design in related technologies cannot balance rotor lightweight and structural stability at high speeds.

[0005] The present invention provides a multi-stage integrated rotor structure of a lightweight turbine power generation integrated machine, including a cantilever shaft, a bearing group, an embedded piezoelectric actuator, a compressor rotor, and a turbine rotor. The cantilever shaft is connected to the shaft end of the generator. The embedded piezoelectric actuator is circumferentially arranged in the non-load-bearing area of the cantilever shaft. The bearing group is mounted on the cantilever shaft. The turbine rotor is coaxially installed at one end of the cantilever shaft. A turbine shaft sleeve is provided at the end of the turbine rotor. The compressor rotor sleeve is arranged on the turbine shaft sleeve;

[0006] A sliding cavity is opened on the back of the impeller of the compressor rotor, and a tuned mass damper is arranged in the sliding cavity. The tuned mass damper is electrically connected to the embedded piezoelectric actuator;

[0007] The bearing group includes an active magnetic suspension bearing and a high-speed ceramic ball bearing. The high-speed ceramic ball bearing is installed on the outer wall of one end of the cantilever shaft close to the turbine rotor, and the active magnetic suspension bearing is oppositely installed on the other end of the cantilever shaft.

[0008] Further, a connecting screw is inserted into the turbine rotor, and the rod end of the connecting screw is threadedly connected to the shaft end of the cantilever shaft. A connecting screw hole is provided on the shaft end of the cantilever shaft.

[0009] Further, a boss joint structure is provided at the joint interface between the compressor rotor and the turbine rotor. A joint boss is provided on the end face of the compressor rotor, and a boss groove is provided on the end face of the turbine rotor.

[0010] Further, an elastic damping bearing seat is arranged on the outer wall of the bearing group, a metal rubber damping ring is added between the outer ring of the high-speed ceramic ball bearing and the housing, and a radial magnetic suspension limiter is added to the end journal of the turbine rotor.

[0011] Furthermore, an interference fit of H7 / u6 is adopted between the turbine shaft sleeve and the compressor rotor. The assembly temperature is cooled by liquid nitrogen, and the interference amount is between 0.03 mm and 0.05 mm.

[0012] Furthermore, circumferential grooves are machined at the root of the cantilever section, and six groups of PZT piezoelectric wafers are embedded. Reverse restraining forces are generated through phase control, and a telecommunication connection is established between the LMS vibration spectrum analyzer and the six groups of PZT piezoelectric wafers.

[0013] Furthermore, an annular cavity is formed on the back of the compressor impeller. The counterweight is slidably connected in the annular cavity, and its radial position is adjusted by a spring group and a magnetic attraction assembly. The adjustment range of the radial position can cover the vibration suppression requirements at 120,000 - 180,000 rpm.

[0014] Furthermore, the spring group includes a first spring and a second spring. The magnetic attraction assembly includes at least two groups of magnetic attraction seats, which are installed on the inner side walls at both ends of the sliding cavity. The first spring and the second spring are installed on the outer walls at both ends of the counterweight. The magnetic attraction seats magnetically attract the counterweight to compress / stretch the first spring / second spring.

[0015] Furthermore, the cantilever shaft adopts a composite structure of a titanium alloy core and a carbon fiber winding layer, and the root of the cantilever shaft adopts a double-curvature transition design.

[0016] Furthermore, a micro oil-gas lubrication channel is also integrated inside the elastic damping bearing seat, and the bearing cavity inside the elastic damping bearing seat is continuously supplied with oil at low pressure through the integrated micro oil-gas lubrication channel.

[0017] The beneficial effects of the present invention are as follows:

[0018] The present invention significantly reduces the rotor weight and enhances the structural rigidity through a composite lightweight structure and an integrated molding process. Combining active magnetic levitation control and a multi-stage passive vibration suppression mechanism, it effectively suppresses vibration transmission and modal resonance during high-speed rotation. Using precision assembly technology and adaptive damping design to achieve high-precision dynamic balance, and at the same time improving the operation reliability under extreme conditions through thermal protection and redundant limit protection, finally achieving the performance goals of an integrated turbine power generation system with high power density, low vibration and noise, and long life. Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of a multi-stage integrated rotor structure of a lightweight turbine power generation integrated machine proposed by the present invention;

[0020] Figure 2 is of the present invention Figure 1 assembly drawing;

[0021] Figure 3It is a schematic view of the back structure of the compressor rotor of the present invention;

[0022] Figure 4 is the Figure 1 schematic vertical cross-sectional view of.

[0023] In the figure: 100, cantilever shaft; 200, embedded piezoelectric actuator; 210, PZT piezoelectric sheet; 300, high-speed ceramic ball bearing; 400, active magnetic bearing; 500, compressor rotor; 600, turbine rotor; 610, turbine shaft sleeve; 620, combined boss; 700, tuned mass damper; 710, counterweight; 720, first spring; 730, second spring; 740, magnetic seat; 800, connecting screw. Specific embodiments

[0024] Now, the subject matter described herein will be discussed with reference to example embodiments. It should be understood that discussing these embodiments is only to enable those skilled in the art to better understand and thus implement the subject matter described herein. Without departing from the scope of protection of the content of this specification, changes can be made to the functions and arrangements of the elements discussed. Each example can omit, substitute, or add various processes or components as needed. Additionally, the features described relative to some examples can also be combined in other examples.

[0025] As Figures 1-4 shown, the multi-stage integrated rotor structure of the lightweight turbo-generator includes several components such as a cantilever shaft 100, a bearing group, an embedded piezoelectric actuator, a compressor rotor 500, and a turbine rotor 600;

[0026] The cantilever shaft 100 is connected to the shaft end of the generator. The embedded piezoelectric actuator is circumferentially arranged in the non-load-bearing area of the cantilever shaft 100. The bearing group is mounted on the cantilever shaft 100. The turbine rotor 600 is coaxially installed at one end of the cantilever shaft 100. A turbine shaft sleeve 610 is provided at the end of the turbine rotor 600. The compressor rotor 500 is sleeved on the turbine shaft sleeve 610;

[0027] A sliding cavity is opened on the back of the impeller of the press rotor, and a tuned mass damper (TMD) 700 is arranged in the sliding cavity. The tuned mass damper 700 is electrically connected to the embedded piezoelectric actuator 200;

[0028] The bearing group includes an active magnetic bearing 400 and a high-speed ceramic ball bearing 300. The high-speed ceramic ball bearing 300 is installed on the outer wall of one end of the cantilever shaft 100 close to the turbine rotor 600. The active magnetic bearing 400 is mounted opposite to each other at the other end of the cantilever shaft 100;

[0029] The connecting screw 800 is inserted into the turbine rotor 600, and the rod end of the connecting screw 800 is threadedly connected to the shaft end of the cantilever shaft 100. It should be noted that a connecting screw hole is provided at the shaft end of the cantilever shaft 100.

[0030] A boss joint structure is provided at the joint interface between the compressor rotor 500 and the turbine rotor 600. Specifically, a joint boss 620 is provided on the end face of the compressor rotor 500, and a boss groove is provided on the end face of the turbine rotor 600.

[0031] The shaft diameter of the cantilever shaft 100 is φ5.95mm, and the material adopts a composite structure of a titanium alloy (TC4) core + a carbon fiber winding layer. The core diameter is φ4.2mm, and the thickness of the carbon fiber layer is 0.875mm (total diameter φ5.95mm), with a 18% reduction in mass.

[0032] It should be noted that the composite structure uses the hot isostatic pressing process to achieve the interface bonding between the titanium alloy and the carbon fiber. The surface layer laser cladding coating (thickness 50μm) improves wear resistance. The root of the cantilever shaft 100 adopts a double-curvature transition design (R = 1.5mm), and weight reduction of 30% is achieved in the non-load-bearing area through topology optimization, and the first-order natural frequency is increased to 215,000 rpm.

[0033] An elastic damping bearing seat is provided on the outer wall of the bearing group. A metal rubber damping ring (thickness 1.5mm, hardness HRC40) is added between the outer ring of the high-speed ceramic ball bearing 300 (opposite installation) and the housing, and the attenuation of the high-frequency vibration transmission rate > 60%. At the same time, a radial magnetic levitation limiter (air gap 0.1mm) is added to the end journal of the turbine rotor 600 as a safety redundancy when the vibration exceeds the limit to prevent the radial displacement of the cantilever section from exceeding 0.05mm.

[0034] It should be noted that a micro oil-gas lubrication channel (aperture φ0.5mm) can also be integrated inside the elastic damping bearing seat, and the bearing cavity is continuously supplied with oil at a pressure of 0.15MPa through the integrated micro oil-gas lubrication channel, and the temperature rise is controlled within 45°C.

[0035] It should be noted that the air gap of the active magnetic levitation bearing 400 is 0.15mm, and the control bandwidth is 2kHz; the preload of the high-speed ceramic ball bearing 300 is 200N, and the contact angle is 15°.

[0036] Among them, the turbine and shaft assembly is integrally printed between the turbine shaft sleeve 610 and the turbine rotor 600 by electron beam melting (EBM) technology. The material is TC4 titanium alloy, and the coaxiality error is <0.5μm. At the same time, an interference fit of H7 / u6 is adopted between the turbine shaft sleeve 610 and the compressor rotor 500, but the assembly temperature is changed from normal temperature to liquid nitrogen cooling (-196°C), and the interference amount is increased from 0.03mm to 0.05mm. After assembly, the residual stress is reduced by 40%. Among them, the turning-grinding-polishing composite process is adopted for the turbine shaft sleeve 610 and the compressor mounting surface, the surface roughness Ra <0.1μm, and the roundness error <0.8μm;

[0037] When setting the embedded piezoelectric actuator 200, a circumferential groove (depth 0.25mm) is machined at the root of the cantilever section, and 6 groups of PZT piezoelectric wafers 210 (thickness 0.15mm) are embedded. A reverse restraining force is generated through phase control. There is a telecommunication connection between the LMS vibration spectrum analyzer and the 6 groups of PZT piezoelectric wafers 210. Based on real-time monitoring by the LMS vibration spectrum analyzer, a voltage of ±180V is output at 160,000 rpm to cancel the first-order vibration mode.

[0038] When setting the tunable mass damper 700, an annular cavity is designed on the back of the compressor impeller, and a counterweight 710 (mass 1.8g) is built-in. The radial position is adjusted through a spring group and a magnetic attraction component (resolution 0.01mm), which can cover the vibration suppression requirements of 120,000 - 180,000 rpm.

[0039] Among them, the spring group in the tunable mass damper 700 includes a first spring 720 and a second spring 730. The magnetic attraction component includes at least two groups of magnetic attraction seats 740. The magnetic attraction seats 740 are installed on the inner side walls at both ends of the sliding cavity. The first spring 720 and the second spring 730 are installed on the outer walls at both ends of the counterweight 710. The magnetic attraction seats 740 magnetically attract the counterweight 710 to compress / stretch the first spring 720 / second spring 730.

[0040] In an embodiment of the present invention, based on the above structure, it specifically includes the following operation stages and processing flows:

[0041] I. System startup and basic operation stage

[0042] Magnetic levitation bearing preloading: When starting, the active magnetic levitation bearing 400 (AMB) is powered on first, and the cantilever shaft 100 is levitated at the center of the air gap (0.15mm) through electromagnetic force to eliminate starting friction;

[0043] The high-speed ceramic ball bearing 300 is in a non-contact standby state, and only 200N of preloading force is retained to maintain axial positioning.

[0044] Turbo Drive and Power Transmission: High-temperature gas drives the rotation of the turbo rotor 600, and the torque is transmitted to the cantilever shaft 100 through the integrally formed turbo shaft sleeve 610 by EBM;

[0045] The compressor rotor 500 is sleeved on the turbo shaft sleeve 610 through an H7 / u6 interference fit, and the combined end face boss structure (boss-groove meshing tolerance ±0.005mm) ensures synchronous rotation.

[0046] II. High-speed Operation and Dynamic Regulation

[0047] Hybrid Bearing Coordinated Load: When the speed is > 100,000 rpm, the magnetic levitation bearing actively adjusts the radial position (bandwidth 2kHz) and bears 80% of the dynamic load;

[0048] The ceramic ball bearing acts as a rigid support, disperses the remaining load through a 15° contact angle, and the metal rubber damping ring (HRC40) absorbs high-frequency vibration energy.

[0049] Embedded Piezoelectric Active Vibration Damping: The LMS vibration analyzer collects the vibration spectrum of the cantilever shaft 100 in real time (sampling rate 10kHz);

[0050] When the first critical frequency (near 215,000 rpm) is detected, a phase compensation voltage (±180V) is output to the 6 groups of PZT piezoelectric wafers 210 to generate a reverse strain force to suppress the amplitude;

[0051] The annular layout of the piezoelectric wafers can make the vibration damping force evenly distributed, and the amplitude decay rate within a single period is > 65%.

[0052] III. Passive Suppression of Broadband Vibration

[0053] Tuned Mass Damper 700 (TMD) Self-adaptation: The TMD counterweight 710 (1.8g) on the back of the compressor impeller is linked with the spring group through the magnetic attraction component:

[0054] Low-speed section (< 120,000 rpm): The magnetic attraction seat 740 releases the adsorption force, and the counterweight 710 contracts towards the axis under the tension of the first spring 720 to match the low-frequency vibration mode;

[0055] High-speed section (> 150,000 rpm): The electromagnetic coil is energized to enhance the magnetic attraction force, stretch the second spring 730 to move the counterweight 710 outwards, and the center of gravity adjustment range is ±3mm to suppress high-frequency whirling.

[0056] Damping Frequency Matching: Through the preset speed-position mapping table, the natural frequency of the TMD dynamically matches the main frequency of the rotor (matching error < 2%), and transfers the vibration energy to the damper for dissipation.

[0057] IV. Extreme Condition Safety Protection

[0058] Magnetic levitation limiter intervention: When the vibration amplitude exceeds the threshold of 0.05 mm, the magnetic levitation limiter at the turbine end starts the strong magnetic field mode (magnetic field strength 1.5 T) to form an instantaneous rigid constraint and prevent the cantilever section from colliding with the housing.

[0059] Thermal-mechanical coupling protection: The surface coating of the cantilever shaft 100 maintains antioxidant properties in a gas environment above 800 °C, and the carbon fiber layer ensures the interface strength through high-temperature epoxy resin (Tg = 320 °C).

[0060] V. Shutdown Coordinated Control

[0061] Sequential unloading: First, cut off the magnetic levitation power supply. The ceramic ball bearings gradually take over all the loads. The counterweight 710 in the TMD resets to the neutral position, and the piezoelectric actuator continuously outputs a slow-release voltage to suppress the residual vibration.

[0062] Through the three-level control strategy of "active suppression - passive energy dissipation - rigid redundancy", this structure can stabilize the vibration amplitude within 5 μm under the condition of 160,000 rpm, a 62% reduction compared with the traditional design, and at the same time achieve a 22% increase in power density (reaching 5.8 kW / kg).

[0063] The above describes the embodiments of the present invention. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms, all of which fall within the protection scope of the present invention.

Claims

1. The multi-stage integrated rotor structure of a lightweight turbo-generator unit, characterized in that It includes a cantilever shaft, a bearing set, an embedded piezoelectric actuator, a compressor rotor, and a turbine rotor. The cantilever shaft is connected to the shaft end of the generator. The embedded piezoelectric actuator is circumferentially arranged in the non-load-bearing area of the cantilever shaft. The bearing set is mounted on the cantilever shaft. The turbine rotor is coaxially installed at one end of the cantilever shaft. A turbine shaft sleeve is provided at the end of the turbine rotor. The compressor rotor sleeve is arranged on the turbine shaft sleeve. A sliding cavity is formed on the back of the impeller of the compressor rotor. A tuned mass damper is arranged in the sliding cavity. The tuned mass damper is electrically connected to the embedded piezoelectric actuator. The bearing set includes an active magnetic bearing and a high-speed ceramic ball bearing. The high-speed ceramic ball bearing is installed on the outer wall of one end of the cantilever shaft close to the turbine rotor. The active magnetic bearing is oppositely installed on the other end of the cantilever shaft.

2. The multi-stage integrated rotor structure of the lightweight turbine generator set according to claim 1, characterized in that A connecting screw is inserted into the turbine rotor. The rod end of the connecting screw is threadedly connected to the shaft end of the cantilever shaft. A connecting screw hole is provided at the shaft end of the cantilever shaft.

3. The multi-stage integrated rotor structure of the lightweight turbine generator set according to claim 2, characterized in that, Among them, a boss joint structure is provided at the joint interface between the compressor rotor and the turbine rotor. Among them, a joint boss is provided on the end face of the compressor rotor, and a boss groove is provided on the end face of the turbine rotor.

4. The multi-stage integrated rotor structure of the lightweight turbine generator set according to claim 3, wherein, An elastic damping bearing seat is arranged on the outer wall of the bearing set. A metal rubber damping ring is added between the outer ring of the high-speed ceramic ball bearing and the housing. A radial magnetic suspension limiter is added to the end journal of the turbine rotor.

5. The multi-stage integrated rotor structure of the lightweight turbine generator set according to claim 4, characterized in that, The turbine shaft sleeve and the compressor rotor are in an interference fit of H7 / u6. The assembly temperature is liquid nitrogen cooling, and the interference amount is between 0.03 mm and 0.05 mm.

6. The multi-stage integrated rotor structure of the lightweight turbine generator set according to claim 5, characterized in that, A circumferential groove is machined at the root of the cantilever section, and 6 groups of PZT piezoelectric wafers are embedded. A reverse restraining force is generated through phase control. The LMS vibration spectrum analyzer is electrically connected to the 6 groups of PZT piezoelectric wafers.

7. The multi-stage integrated rotor structure of the lightweight turbine generator set according to claim 6, characterized in that, An annular cavity is formed on the back of the compressor impeller. A counterweight is slidably connected in the annular cavity. The radial position is adjusted through a spring group and a magnetic attraction assembly. The adjustment range of the radial position can cover the vibration suppression requirements of 120,000 - 180,000 rpm.

8. The multi-stage integrated rotor structure of the lightweight turbine generator set according to claim 7, characterized in that, The spring group includes a first spring and a second spring. The magnetic attraction assembly includes at least two groups of magnetic attraction seats. The magnetic attraction seats are installed on the inner side walls at both ends of the sliding cavity. The first spring and the second spring are installed on the outer walls at both ends of the counterweight. The magnetic attraction seats magnetically attract the counterweight to compress / stretch the first spring / second spring.

9. The multi-stage integrated rotor structure of the lightweight turbine generator set according to claim 8, characterized in that, The cantilever shaft adopts a composite structure of a titanium alloy core and a carbon fiber winding layer. The root of the cantilever shaft adopts a double-curvature transition design.

10. The multi - stage integrated rotor structure of the lightweight turbine - generator integrated machine according to claim 9, characterized in that, A micro oil and gas lubrication channel is also integrated inside the elastic damping bearing seat. The bearing cavity inside the elastic damping bearing seat is continuously supplied with oil at low pressure through the integrated micro oil and gas lubrication channel.

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