CN108868911B

CN108868911B - Power generation system and control method thereof

Info

Publication number: CN108868911B
Application number: CN201810032620.1A
Authority: CN
Inventors: 靳普
Original assignee: Liu Muhua
Current assignee: Liu Muhua
Priority date: 2018-01-12
Filing date: 2018-01-12
Publication date: 2024-03-19
Anticipated expiration: 2038-01-12
Also published as: CN108868911A

Abstract

The invention provides a power generation system and a control method thereof, wherein the power generation system comprises: waste heat boilers, tesla turbines and motors; the Tesla turbine is connected with the motor and is used for driving the motor to work; the tesla turbine is provided with a medium inlet and a medium outlet; the waste heat boiler comprises a shell, wherein liquid medium is filled in the shell, and at least one heat exchanger for converting the liquid medium into vapor medium is also arranged in the shell and immersed in the liquid medium; the shell is provided with a steam pipeline communicated with the medium inlet and a condensation pipeline communicated with the medium outlet; the at least one heat exchanger comprises a first heat exchanger, a heat medium inlet of the first heat exchanger is communicated with an exhaust pipe of the gas turbine, and a heat medium outlet of the first heat exchanger is positioned outside the shell. The invention improves the efficiency of the gas-steam combined cycle power generation system by using a high efficiency tesla turbine as a steam turbine.

Description

Power generation system and control method thereof

Technical Field

The invention relates to the technical field of power generation, in particular to a power generation system and a control method thereof.

Background

The efficiency of the gas-steam combined cycle power generation system is related to the gas cycle efficiency (i.e., the efficiency of the gas turbine) and the steam cycle efficiency (i.e., the efficiency of the steam turbine), and improving either the gas cycle efficiency or the steam cycle efficiency can improve the efficiency of the gas-steam combined cycle power generation system. Wherein, the improvement of the steam circulation efficiency is mainly realized by increasing the steam inlet parameters of the steam turbine. In the prior art, a steam turbine is usually a steam turbine, and the steam turbine has higher requirements on the quality and parameters of steam, so that the parameters of inlet flue gas of a waste heat boiler are also higher. In combined cycle, the flue gas temperature at the gas turbine outlet needs to be increased to meet the requirements of higher parameters at the steam outlet of the waste heat boiler, which can lead to reduced work output of the gas turbine.

It can be seen that the efficiency of the existing gas-steam combined cycle power generation system cannot be further improved due to the limitation of the steam turbine.

Disclosure of Invention

The invention provides a power generation system and a control method thereof, which are used for solving the problem that the efficiency of the existing gas-steam combined cycle power generation system cannot be further improved due to the limitation of a steam turbine.

In a first aspect, the present invention provides a power generation system comprising:

Waste heat boilers, tesla turbines and motors;

the Tesla turbine is connected with the motor and is used for driving the motor to work;

the tesla turbine is provided with a medium inlet and a medium outlet;

the waste heat boiler comprises a shell, wherein a liquid medium is filled in the shell, and at least one heat exchanger for converting the liquid medium into a vaporous medium is also arranged in the shell and is immersed in the liquid medium; the shell is provided with a steam pipeline communicated with the medium inlet and a condensation pipeline communicated with the medium outlet;

the at least one heat exchanger comprises a first heat exchanger, a heat medium inlet of the first heat exchanger is communicated with an exhaust pipe of the gas turbine, and a heat medium outlet of the first heat exchanger is positioned outside the shell.

Optionally, the at least one heat exchanger further comprises a second heat exchanger, and a heat medium inlet of the second heat exchanger is communicated with the condensation pipeline.

Optionally, the liquid medium is water.

Optionally, the first heat exchanger and the second heat exchanger are both tubular heat exchangers, and the tubular heat exchangers include:

The heat exchange device comprises a first pipe body, a second pipe body and a heat exchange element, wherein the outer diameter of the first pipe body is smaller than the inner diameter of the second pipe body, and the second pipe body is sleeved outside the first pipe body;

a plurality of heat exchange elements are attached and connected between the inner wall of the first pipe body and the outer wall of the first pipe body and the inner wall of the second pipe body, and gaps are formed between any two adjacent heat exchange elements;

the space between the outer wall of the first pipe body and the inner wall of the second pipe body forms a refrigerant channel, and the space surrounded by the first pipe body forms a heating medium channel;

the first pipe body of the first heat exchanger is connected with the exhaust pipe of the gas turbine, the first pipe body of the second heat exchanger is connected with the outlet of the condensing pipeline, and liquid media in the shell are respectively communicated with the second pipe body of the first heat exchanger and the second pipe body of the second heat exchanger.

Optionally, a gap is disposed between any two adjacent heat exchange elements along the axial direction and the radial direction of the first tube body.

Optionally, the heat exchange element is in a regular structure or an irregular structure.

Optionally, when the heat exchange element is in a regular structure, the heat exchange element is a corrugated plate, a fin plate or a water drop shape with the shape of the heat exchange element in the direction of flow;

When the appearance of the heat exchange element is of an irregular structure, the appearance of the heat exchange element is coral-shaped or burr-shaped.

Optionally, the tesla turbine comprises:

a rotating shaft;

the shell is arranged on the rotating shaft and is provided with a medium inlet and a medium outlet;

the plurality of discs are arranged in the shell and fixedly connected to the rotating shaft, gaps are formed between every two adjacent discs in the plurality of discs, and at least one exhaust hole is formed in each disc in the plurality of discs;

and the thrust bearing and the at least two radial bearings are non-contact bearings.

Optionally, the thrust bearing is disposed within the housing;

the at least two radial bearings comprise a first radial bearing and a second radial bearing, and the first radial bearing and the second radial bearing are respectively arranged on two sides of the shell.

Optionally, the thrust bearing is a gas-magnetic hybrid thrust bearing;

at least one radial bearing in the at least two radial bearings is a gas-magnetic hybrid radial bearing or a gas-dynamic-static pressure hybrid radial bearing.

Optionally, the air-magnetic hybrid thrust bearing is a foil type air-magnetic hybrid thrust bearing, and the foil type air-magnetic hybrid thrust bearing includes:

the first thrust disc is fixedly connected to the rotating shaft;

the first stator and the second stator are arranged on the opposite sides of the first thrust disc in a penetrating manner;

each of the first stator and the second stator comprises a first magnetic bearing and a first foil bearing, a plurality of first magnetic components are arranged on the first magnetic bearing along the circumferential direction, and a second magnetic component capable of generating magnetic force with the plurality of first magnetic components is arranged on the first foil bearing;

the first foil bearing is arranged between the first magnetic bearing and the first thrust disc, a first gap is reserved between the first foil bearing and the first thrust disc, and the first foil bearing can move in the axial direction of the rotating shaft under the action of magnetic force between the first magnetic component and the second magnetic component.

Optionally, the air-magnetic hybrid thrust bearing is a groove type air-magnetic hybrid thrust bearing, and the groove type air-magnetic hybrid thrust bearing comprises:

The second thrust disc is fixedly connected to the rotating shaft and is provided with a third magnetic component;

the third stator and the fourth stator are arranged on the opposite sides of the second thrust disc in a penetrating manner;

each of the third stator and the fourth stator includes a second magnetic bearing on which a plurality of fourth magnetic members capable of generating magnetic force with the third magnetic member are circumferentially provided, a second gap is provided between the second magnetic bearing and the second thrust disk, and the second thrust disk is movable in an axial direction of the rotating shaft under a magnetic force between the third magnetic member and the plurality of fourth magnetic members;

and the end surfaces of the second thrust disc facing the third stator and the fourth stator, or the end surfaces of the third stator and the fourth stator facing the second thrust disc are provided with second dynamic pressure generating grooves.

Optionally, the air-magnetic hybrid radial bearing is a foil-type air-magnetic hybrid radial bearing, and the foil-type air-magnetic hybrid radial bearing includes:

The third magnetic bearing is sleeved on the rotating shaft, and a plurality of fifth magnetic components are arranged on the third magnetic bearing along the circumferential direction;

the second foil bearing is sleeved on the rotating shaft and positioned between the third magnetic bearing and the rotating shaft, and a sixth magnetic component capable of generating magnetic force with the plurality of fifth magnetic components is arranged on the second foil bearing;

and a third gap is formed between the second foil bearing and the rotating shaft, and the second foil bearing can move in the radial direction of the rotating shaft under the action of the magnetic force of the fifth magnetic components and the sixth magnetic components.

Optionally, the air-magnetic hybrid radial bearing is a groove-type air-magnetic hybrid radial bearing, and the groove-type air-magnetic hybrid radial bearing includes:

the fourth magnetic bearing is sleeved on the rotating shaft, and a plurality of seventh magnetic components are arranged on the fourth magnetic bearing along the circumferential direction;

a third dynamic pressure generating groove is arranged on the circumferential surface of the fourth magnetic bearing facing to the side wall of the rotating shaft or the rotating shaft facing to the fourth magnetic bearing;

and a fourth gap is formed between the fourth magnetic bearing and the rotating shaft, and the rotating shaft can move in the radial direction of the rotating shaft under the action of the magnetic force of the seventh magnetic components.

Optionally, the fourth magnetic bearing is further provided with a static pressure air inlet orifice, one end of the static pressure air inlet orifice is communicated with the fourth gap, and the other end of the static pressure air inlet orifice is connected with an external air source and used for conveying the external air source into the fourth gap.

In a second aspect, the present invention also provides a control method of a power generation system, including:

high-temperature gas exhausted by an exhaust pipe of the gas turbine enters the first heat exchanger through a heat medium inlet of the first heat exchanger, exchanges heat with a liquid medium in a shell of the waste heat boiler, and is exhausted out of the shell of the waste heat boiler through a heat medium outlet of the first heat exchanger after heat exchange;

the liquid medium in the shell of the waste heat boiler is heated to become steam, the steam enters a Tesla turbine through a steam pipeline of the shell, and the steam drives the Tesla turbine to work so as to drive the motor to generate electricity;

the temperature of the steam is reduced after the steam works, the steam is discharged out of the Tesla turbine through a medium outlet of the Tesla turbine and returns to the shell through the condensation pipeline;

the reduced temperature steam exiting the tesla turbine exchanges heat with the liquid medium in the shell to raise the temperature of the liquid medium in the shell.

Optionally, the heat exchange between the steam discharged from the tesla turbine and the liquid medium in the shell after the temperature reduction, so as to increase the temperature of the liquid medium in the shell, including:

and the steam with the reduced temperature discharged by the Tesla turbine enters the second heat exchanger through a heat medium inlet of the second heat exchanger to exchange heat with the liquid medium in the shell, so that the temperature of the liquid medium in the shell is increased.

In the invention, the efficiency of the gas-steam combined cycle power generation system is improved by using the high-efficiency Tesla turbine as the steam turbine.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a power generation system according to a first embodiment;

FIG. 2 is a flow chart of a control method of a power generation system according to the first embodiment;

FIG. 3 is a schematic view of a Tesla turbine provided in a second embodiment;

FIG. 4 is a flow chart of a control method of a Tesla turbine provided in the second embodiment;

FIG. 5 is a flow chart of another method of controlling a Tesla turbine provided in embodiment two;

fig. 6 is a schematic structural view of a tubular heat exchanger provided in the third embodiment;

FIG. 7 is a schematic view of the structure in the direction A-A in FIG. 6;

FIG. 8 is an enlarged schematic view of the portion B of FIG. 6;

FIG. 9 is a schematic view showing the flow of air when the heat exchange element in the third embodiment is in the shape of water droplets in the direction of flow;

fig. 10 is a schematic structural view of a heat exchanger including four tube bodies provided in the third embodiment;

FIG. 11 is a cross-sectional view of FIG. 10;

FIG. 12 is a schematic flow chart of a method for manufacturing a tubular heat exchanger according to the third embodiment;

FIG. 13 is a cross-sectional view of a foil type hybrid aero-magnetic thrust bearing provided in accordance with a fourth embodiment;

FIG. 14 is a schematic structural view of a first magnetic bearing in a foil type aero-magnetic hybrid thrust bearing according to a fourth embodiment;

FIG. 15 is a schematic view of a first magnetic bearing seat in a foil type hybrid aero-magnetic thrust bearing according to a fourth embodiment;

FIG. 16 is a schematic view of a first foil in a foil type aero-magnetic hybrid thrust bearing according to a fourth embodiment;

FIG. 17 is a cross-sectional view of a groove type air-magnetic hybrid thrust bearing provided in embodiment five;

FIG. 18 is a schematic structural view of a second magnetic bearing in a groove-type aero-magnetic hybrid thrust bearing according to a fifth embodiment;

FIG. 19 is a schematic view of a second magnetic bearing seat in a groove-type aero-magnetic hybrid thrust bearing according to a fifth embodiment;

fig. 20 is one of schematic structural views of a groove-type air-magnetic hybrid thrust bearing provided in the fifth embodiment in which a second dynamic pressure generating groove is provided on a second thrust disk;

fig. 21 is a second schematic diagram of a structure in which a second dynamic pressure generating groove is provided on a second thrust disk in a groove type air-magnetic hybrid thrust bearing provided in the fifth embodiment;

fig. 22 is one of schematic structural diagrams of a groove type air-magnetic hybrid thrust bearing provided in the fifth embodiment, in which a second dynamic pressure generating groove is provided on a first pressure ring;

fig. 23 is a second schematic diagram of a structure in which a second dynamic pressure generating groove is provided in a first pressure ring in a groove type air-magnetic hybrid thrust bearing according to the fifth embodiment;

FIG. 24 is a cross-sectional view of a foil type hybrid gas-magnetic radial bearing provided in embodiment six;

FIG. 25 is an external view of a foil type air-magnetic hybrid radial bearing provided in embodiment six;

FIG. 26 is a schematic structural view of a third magnetic bearing seat in a foil type hybrid gas-magnetic radial bearing according to a sixth embodiment;

Fig. 27 is a schematic structural diagram of a fourth foil with strip-shaped magnetic materials distributed thereon in a foil-type air-magnetic hybrid radial bearing according to a sixth embodiment;

fig. 28 is a schematic structural diagram of a fourth foil with dot magnetic materials distributed thereon in a foil-type air-magnetic hybrid radial bearing according to a sixth embodiment;

FIG. 29 is an enlarged schematic view of portion A of FIG. 24;

FIG. 30 is a half cross-sectional view of a groove type air-magnetic hybrid radial bearing provided in embodiment seven;

FIG. 31 is a half cross-sectional view of another groove type air-magnetic hybrid radial bearing provided in embodiment seven;

FIG. 32 is an external view of a groove-type air-magnetic hybrid radial bearing provided in embodiment seven;

FIG. 33 is a schematic structural view of a fourth magnetic bearing in a groove-type air-magnetic hybrid radial bearing according to a seventh embodiment;

FIG. 34 is a schematic view of a fourth magnetic bearing seat in a groove-type hybrid gas-magnetic radial bearing according to the seventh embodiment;

FIG. 35 is a schematic view of a structure in which a third dynamic pressure generating groove is provided on a second bearing sleeve in a groove type air-magnetic hybrid radial bearing according to a seventh embodiment;

FIG. 36 is a second schematic view of a third dynamic pressure generating groove formed in a second bearing sleeve in a groove type air-magnetic hybrid radial bearing according to the seventh embodiment;

Fig. 37 is a schematic structural view of a groove-type air-magnetic hybrid radial bearing according to the seventh embodiment, in which a third dynamic pressure generating groove is provided on the rotating shaft.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

As shown in fig. 1 to 2, a power generation system includes:

a waste heat boiler 1, a tesla turbine 2 and a motor 3;

the Tesla turbine 2 is connected with the motor 3, and the Tesla turbine 2 is used for driving the motor 3 to work;

the tesla turbine 2 is provided with a medium inlet and a medium outlet;

the waste heat boiler 1 comprises a shell 11, wherein liquid medium is filled in the shell 11, and at least one heat exchanger for converting the liquid medium into vapor medium is arranged in the shell 11 and immersed in the liquid medium; the shell 11 is provided with a steam pipeline 12 communicated with the medium inlet and a condensation pipeline 13 communicated with the medium outlet;

The heat exchanger comprises a first heat exchanger 4, a heat medium inlet of the first heat exchanger 4 is communicated with an exhaust pipe 51 of the gas turbine 5, and a heat medium outlet of the first heat exchanger 4 is positioned outside the shell 11.

Wherein the liquid medium is preferably water, and the vapor medium is preferably steam; the steam line 12 is preferably integrally formed with the housing 11.

The tesla turbine 2 and the motor 3 may be connected through an integral rotating shaft, or the rotating shaft of the tesla turbine 2 may be connected to the rotating shaft of the motor 3 through a coupling 7, which is not limited in the embodiment of the present invention.

In the embodiment of the invention, the efficiency of the gas-steam combined cycle power generation system is improved by using the high-efficiency Tesla turbine as the steam turbine. Specific embodiments of tesla turbines are described in detail below.

Optionally, the heat exchanger further comprises a second heat exchanger 6, and a heat medium inlet of the second heat exchanger 6 is communicated with the condensation pipeline 13.

In the embodiment of the invention, the steam with the reduced temperature enters the heat medium inlet of the second heat exchanger 6 and exchanges heat with the liquid medium in the shell 11.

Here, in order to improve heat exchange efficiency, the first heat exchanger 4 and the second heat exchanger 6 may each be a tube heat exchanger, and detailed description will be given later on for the specific embodiment of the tube heat exchanger.

In this application, gas turbine includes pivot and sets up in epaxial compressor, combustion chamber, turbine, thrust bearing and radial bearing.

Wherein, the thrust bearing and the radial bearing of the gas turbine can both adopt non-contact bearings. Thrust bearings and radial bearings employed in tesla turbines are equally applicable to gas turbines. Reference is made to the following description for specific embodiments of both thrust bearings and radial bearings in a gas turbine.

The rotating shaft of the gas turbine can be horizontally arranged or vertically arranged; the compressor and the turbine of the gas turbine may be disposed back-to-back in the same casing.

In this application, the gas turbine may also be an existing gas turbine, and thus, the gas turbine is not specifically described herein.

As shown in fig. 2, the embodiment of the present invention further provides a control method of a power generation system, including:

s11, high-temperature gas discharged by an exhaust pipe of the gas turbine enters the first heat exchanger through a heat medium inlet of the first heat exchanger, exchanges heat with liquid medium in a shell of the waste heat boiler, and after heat exchange, the high-temperature gas is discharged out of the shell of the waste heat boiler through a heat medium outlet of the first heat exchanger.

S12, heating the liquid medium in the shell of the waste heat boiler to form steam, enabling the steam to enter the Tesla turbine through a steam pipeline of the shell, and driving the Tesla turbine to work by the steam so as to drive the motor to generate power.

S13, the temperature of the steam is reduced after the steam works, the steam is discharged out of the Tesla turbine through a medium outlet of the Tesla turbine, and the steam returns to the shell through a condensing pipeline.

S14, heat exchange is carried out between the steam discharged by the Tesla turbine and the liquid medium in the shell, so that the temperature of the liquid medium in the shell is increased.

In the above process, the high temperature gas discharged from the exhaust pipe 51 of the gas turbine 5 enters the heat medium inlet of the first heat exchanger 4 to exchange heat with the liquid medium in the housing 11, after the heat exchange, the temperature of the high temperature gas is reduced and discharged out of the housing 11, part of the liquid medium in the housing 11 absorbs the heat of the high temperature gas to raise the temperature and become high temperature steam, the high temperature steam is conveyed into the tesla turbine 2 through the steam pipeline 12 and the medium inlet, and the high temperature steam drives the tesla turbine 2 to work so as to drive the motor 3 to generate electricity. The high-temperature steam is cooled after acting, is discharged out of the Tesla turbine through a medium outlet of the Tesla turbine, returns to the shell 11 through the condensing pipeline 13, and is converted into a liquid medium to enter the next working cycle.

Optionally, the reduced temperature steam exiting the tesla turbine exchanges heat with a liquid medium within the housing to raise the temperature of the liquid medium within the housing, comprising:

the steam with reduced temperature discharged by the Tesla turbine enters the second heat exchanger through a heat medium inlet of the second heat exchanger and exchanges heat with the liquid medium in the shell, so that the temperature of the liquid medium in the shell is increased.

In order to better understand the technical scheme of the embodiment of the invention, the specific structure of the tesla turbine in the power generation system and the specific structure of the connection of the tesla turbine and the motor are described in detail below.

Example two

As shown in fig. 3, a tesla turbine 2 comprises:

a rotating shaft 100;

a housing 200 disposed on the rotating shaft 100, wherein a medium inlet (not shown) and a medium outlet (not shown) are disposed on the housing 200;

the device comprises a plurality of discs 300 arranged in a shell 200, wherein the discs 300 are fixedly connected to a rotating shaft 100, gaps 400 are formed between every two adjacent discs 300 in the discs 300, and at least one exhaust hole 301 is formed in each disc 300 in the discs 300;

and a thrust bearing 500 and at least two radial bearings provided on the rotating shaft 100, the thrust bearing 500 and the at least two radial bearings being non-contact bearings.

In the embodiment of the invention, the tesla turbine works as follows: the high-speed fluid medium enters the inside of the housing 200 through the medium inlet provided on the housing 200, and the fluid medium enters the gap 400 between the adjacent disks 300 through the exhaust holes 301. Due to the fluid boundary effect, the fluid medium drives the disc 300 to rotate at a high speed, thereby driving the spindle 100 to rotate. The fluid medium passes through the exhaust holes 301 of each disc 300 in turn and finally exits the housing 200 through the medium outlet provided in the housing 200. The rotation of the rotating shaft 100 drives the rotation shaft 310 of the motor 3 to rotate so as to realize the power generation of the motor 3.

In an embodiment of the invention, the rotating shaft 100 of the tesla turbine may be connected to the rotating shaft 310 of the motor 3 via a coupling 7. Of course, the motor 3 may be directly disposed on the rotating shaft 100.

Further, the motor 3 is a dynamic pressure bearing motor, and the portion of the rotating shaft 310 corresponding to the bearing of the motor 3 is provided with a first dynamic pressure generating groove 311.

Further, the motor 3 may also be a heuristic motor.

Thus, at the time of initial start-up of the tesla turbine, the motor 3 may be turned on in a start-up mode to rotate the tesla turbine, and after the rotational speed of the tesla turbine is increased to a preset rotational speed, the operation mode of the motor 3 may be switched to a generation mode.

In the embodiment of the present invention, the thrust bearing 500 is a bearing for restricting the movement of the rotating shaft 100 in the axial direction, and the radial bearing is a bearing for restricting the movement of the rotating shaft 100 in the radial direction. The number of radial bearings is at least two, so that the rotation shaft 100 can be kept stable during high-speed rotation.

In the embodiment of the invention, the power loss of the Tesla turbine on the bearing is reduced by adopting the non-contact thrust bearing and the radial bearing in the Tesla turbine, thereby being beneficial to improving the efficiency of the Tesla turbine.

Optionally, a thrust bearing 500 is disposed within the housing 200;

the at least two radial bearings include a first radial bearing 600 and a second radial bearing 700, and the first radial bearing 600 and the second radial bearing 700 are disposed at both sides of the housing 200, respectively.

In this way, the center of gravity of the tesla turbine is advantageously located between the first radial bearing 600 and the second radial bearing 700, which is advantageous for improving the stability of the tesla turbine during high-speed rotation.

Alternatively, the vent holes 301 on each of the plurality of disks 300 are coaxially disposed.

In this way, the fluid medium can more smoothly and rapidly pass through the exhaust holes 301 into the gap 400 between any adjacent disks 300, thereby contributing to the improvement of the operating efficiency of the tesla turbine.

Alternatively, since the high-speed fluid medium enters from the outer edge of the disc 300 and then is discharged from the exhaust holes 301, in order to improve the operation efficiency of the tesla turbine, the distance between the exhaust holes 301 on each of the discs 300 to the rotating shaft 100 is smaller than the distance between the exhaust holes 301 to the outer edge of the disc 300.

Optionally, two exhaust holes 301 are provided on each disc 300 of the plurality of discs 300, and the two exhaust holes 301 are symmetrically arranged with the rotating shaft 100 as a symmetry axis.

Thus, by symmetrically providing the two exhaust holes 301, the operating efficiency of the tesla turbine can be further improved.

Optionally, a plurality of discs 300 are attached to the shaft 100 by a key 302 and secured to the shaft 100 by a spring washer 303.

In the embodiment of the present invention, the manner of fixedly connecting the disc 300 and the rotating shaft 100 is not limited to the above manner, for example, the disc 300 may be fixed on the rotating shaft 100 by welding, integral molding, or the like. Wherein, the disc 300 is connected to the rotating shaft 100 by the key 302, which is beneficial to facilitate the installation, adjustment and disassembly of the disc 300.

Optionally, a spacer 304 is disposed between two adjacent discs 300 in the plurality of discs 300, and the spacer 304 is used to adjust the size of the gap 400 between the two adjacent discs 300.

In the embodiment of the present invention, the size of the gap 400 between two adjacent disks 300 has a certain effect on the operating efficiency of the tesla turbine, and too small or too large a gap 400 may result in a decrease in the operating efficiency of the tesla turbine. Therefore, in the preferred embodiment of the present invention, the size of the gap 400 between two adjacent discs 300 is adjusted by the spacer 304, which is beneficial to flexibly adjusting the size of the gap 400 between two adjacent discs 300 according to the actual working conditions.

Optionally, thrust bearing 500 is a hybrid gas-magnetic thrust bearing;

at least one radial bearing of the at least two radial bearings is a gas-magnetic hybrid radial bearing.

Currently, non-contact bearings generally include electromagnetic bearings and air bearings. However, the electromagnetic bearing has the problems of too high energy consumption, heat generation and the like when being opened for a long time; and when the surface linear speed of the air bearing approaches or exceeds the sonic speed, shock waves can be generated, so that the bearing is unstable, and even catastrophic results such as shaft collision and the like are generated.

Therefore, in order to improve the working performance of the thrust bearing and the radial bearing, in the embodiment of the present invention, the thrust bearing 500 may be a gas-magnetic hybrid thrust bearing, the first radial bearing 600 may be a gas-magnetic hybrid radial bearing, and the second radial bearing 700 may be a gas-magnetic hybrid radial bearing.

The control method of the tesla turbine is described in detail below.

As previously mentioned, the thrust bearing in the tesla turbine may be a gas-magnetic hybrid thrust bearing, and the radial bearing may be a gas-magnetic hybrid thrust bearing or a gas-dynamic-static hybrid radial bearing. For convenience of description, a bearing that can perform lubrication without rotation of the rotation shaft 100 is defined as a hydrostatic bearing, and a bearing that can be operated when the rotation shaft 100 rotates to a certain speed is defined as a hydrodynamic bearing. According to the logic, the magnetic bearing and the aerostatic bearing in the aeromagnetic hybrid thrust bearing and the aerostatic bearing in the aerostatic hybrid radial bearing can be called as hydrostatic bearings; the aerodynamic bearing in the aerodynamic-magnetic hybrid thrust bearing and the aerodynamic bearing in the aerodynamic-static hybrid radial bearing can be called dynamic pressure bearings.

As shown in fig. 4, an embodiment of the present invention provides a control method of a tesla turbine, including:

s101, opening hydrostatic bearings in the radial bearing and the thrust bearing to enable the rotating shaft to move to a preset radial position, and enabling a thrust disc of the thrust bearing to move to a preset axial position.

Wherein, open hydrostatic bearing includes: the magnetic bearings in the bearings are turned on and/or gas is delivered to static pressure inlet orifices in the bearings.

S102, inputting fluid medium into the shell through the medium inlet, wherein the fluid medium drives a plurality of discs to rotate, and the discs drive the rotating shaft to rotate.

Wherein the fluid medium may be steam.

S103, after the rotating speed of the rotating shaft is accelerated to the working rotating speed, closing the hydrostatic bearings in the radial bearing and the thrust bearing.

Wherein closing the hydrostatic bearing comprises: closing the magnetic bearing in the bearing and/or stopping the delivery of gas to the static pressure inlet orifice in the bearing.

And S104, when the Tesla turbine is stopped, opening the hydrostatic bearings in the radial bearings and the hydrostatic bearings in the thrust bearings.

S105, after the rotating speed of the rotating shaft is reduced to zero, closing the hydrostatic bearings in the radial bearing and the thrust bearing.

In the above process, before the tesla turbine is started, the bearings in the tesla turbine are controlled so that the hydrostatic bearings of the radial bearings and the thrust bearings are opened. In this way, the rotating shaft is supported to a preset radial position under the action of the hydrostatic bearing of the radial bearing; the thrust disc is pushed to a preset axial position under the action of a hydrostatic bearing of the thrust bearing. The hydrostatic bearings in the radial bearing and the thrust bearing are always opened until the rotating speed of the rotating shaft reaches the working rotating speed.

When the Tesla turbine is stopped, the bearings in the Tesla turbine are controlled, so that the hydrostatic bearings in the radial bearings and the thrust bearings are always opened until the rotating speed of the rotating shaft is zero.

As shown in fig. 5, an embodiment of the present invention provides another control method of a tesla turbine, including:

s201, opening the hydrostatic bearings in the radial bearing and the thrust bearing to enable the rotating shaft to move to a preset radial position, and enabling the thrust disc of the thrust bearing to move to a preset axial position.

Wherein, open hydrostatic bearing, include: the magnetic bearing in the bearing is turned on and/or gas is delivered to the static pressure intake orifice in the bearing.

S202, inputting fluid medium into the shell through the medium inlet, wherein the fluid medium drives a plurality of discs to rotate, and the discs drive the rotating shaft to rotate.

S203, after the rotating speed of the rotating shaft is accelerated to a first preset value, closing the hydrostatic bearings in the radial bearing and the thrust bearing.

The first preset value may be 5% to 30% of the rated rotational speed.

Wherein, close hydrostatic bearing, include: closing the magnetic bearing in the bearing and/or stopping the delivery of gas to the static pressure inlet orifice in the bearing.

S204, when the rotating speed of the rotating shaft is accelerated to a first-order critical speed or a second-order critical speed, starting the hydrostatic bearings in the radial bearing and the thrust bearing.

S205, after the rotating speed of the rotating shaft steadily passes the first-order critical speed or the second-order critical speed, closing the hydrostatic bearings in the radial bearing and the thrust bearing.

And S206, in the shutdown process of the Tesla turbine, when the rotating speed of the rotating shaft is reduced to a first-order critical speed or a second-order critical speed, opening the hydrostatic bearings in the radial bearings and the thrust bearings.

S207, after the rotating speed of the rotating shaft steadily passes the first-order critical speed or the second-order critical speed, closing the hydrostatic bearings in the radial bearing and the thrust bearing.

And S208, when the rotating speed of the rotating shaft is reduced to a second preset value, starting the hydrostatic bearings in the radial bearings and the hydrostatic bearings in the thrust bearings.

The second preset value may be equal to or different from the first preset value, and the second preset value may be 5% to 30% of the rated rotation speed.

S209, after the rotating speed of the rotating shaft is reduced to zero, closing the hydrostatic bearings in the radial bearing and the thrust bearing.

In the above process, before the tesla turbine is started, the bearings in the tesla turbine are controlled so that the hydrostatic bearings of the radial bearings and the thrust bearings are opened. In this way, the rotating shaft is supported to a preset radial position under the action of the hydrostatic bearing of the radial bearing; the thrust disc is pushed to a preset axial position under the action of a hydrostatic bearing of the thrust bearing.

After the tesla turbine is started, the rotating speed of the rotating shaft is gradually increased, and when the rotating speed of the rotating shaft reaches a first preset value, for example, 5-30% of the rated rotating speed, the bearings in the tesla turbine are controlled to stop the operation of the hydrostatic bearings in the radial bearings and the thrust bearings. When the rotating speed of the rotating shaft reaches a first-order critical speed or a second-order critical speed, the bearings in the Tesla turbine are controlled, so that the hydrostatic bearings of the radial bearings and the thrust bearings are restarted. After the rotating speed of the rotating shaft steadily passes the first-order critical speed or the second-order critical speed, the bearings in the Tesla turbine are controlled, so that the static pressure bearings in the radial bearings and the thrust bearings stop working again.

In the stop process of the Tesla turbine, the rotating speed of the rotating shaft gradually decreases, and when the rotating speed of the rotating shaft reaches a second-order critical speed or a first-order critical speed, the bearings in the Tesla turbine are controlled, so that the hydrostatic bearings of the radial bearings and the thrust bearings are restarted. After the rotation speed of the rotating shaft steadily passes the second-order critical speed or the first-order critical speed, the bearings in the Tesla turbine are controlled, so that the hydrostatic bearings in the radial bearings and the thrust bearings stop working again. When the rotation speed of the rotating shaft is reduced to a preset value, for example, 5-30% of the rated rotation speed, the bearings in the Tesla turbine are controlled, so that the hydrostatic bearings of the radial bearings and the thrust bearings are opened again until the rotation speed is reduced to zero, and then the bearings in the Tesla turbine are controlled, so that the hydrostatic bearings of the radial bearings and the thrust bearings are stopped again.

In view of the foregoing, we clearly understand the overall structure of the tesla turbine and the control method of the tesla turbine provided in the embodiments of the present invention.

It should be noted that the air-magnetic hybrid thrust bearing and the air-magnetic hybrid radial bearing may take various structural forms. For the aero-magnetic hybrid thrust bearing, a foil type aero-magnetic hybrid thrust bearing or a slot type aero-magnetic hybrid thrust bearing can be included; for the aero-magnetic hybrid radial bearing, a foil aero-magnetic hybrid radial bearing or a groove aero-magnetic hybrid radial bearing may be included. The specific embodiments of the various bearings described above will be described in detail later.

In order to better understand the technical scheme of the embodiment of the invention, the specific structure and the preparation method of the tubular heat exchanger are described in detail below when the first heat exchanger and the second heat exchanger in the power generation system are both tubular heat exchangers.

Example III

As shown in fig. 6 to 9, the tube heat exchanger includes:

the heat exchange device comprises a first pipe body 10, a second pipe body 20 and a heat exchange element 30, wherein the outer diameter of the first pipe body 10 is smaller than the inner diameter of the second pipe body 20, and the second pipe body 20 is sleeved outside the first pipe body 10;

a plurality of heat exchange elements 30 are attached and connected between the inner wall of the first pipe body 10 and the outer wall of the first pipe body 10 and the inner wall of the second pipe body 20, and gaps are arranged between any two adjacent heat exchange elements 30;

The space between the outer wall of the first tube body 10 and the inner wall of the second tube body 20 forms a refrigerant channel, and the space surrounded by the first tube body 10 forms a heating medium channel.

When the tubular heat exchanger of the embodiment of the invention is applied to a power generation system, the first pipe body 10 of the first heat exchanger 4 is connected with the exhaust pipe 51 of the gas turbine 5, the first pipe body 10 of the second heat exchanger 6 is connected with the outlet of the condensation pipeline 13, and the liquid medium in the shell 11 is respectively communicated with the second pipe body 20 of the first heat exchanger 4 and the second pipe body 20 of the second heat exchanger 6.

In the embodiment of the invention, the two channels for the heat exchange medium to flow are formed by the two sleeved pipes, the structure is very simple, the resistance generated in the process of flowing the heat exchange medium is smaller than that in the prior art, and the heat exchange efficiency is higher than that in the prior art.

In the embodiment of the present invention, a plurality of heat exchange elements 30 are attached between the inner wall of the first pipe body 10 and the outer wall of the first pipe body 10 and the inner wall of the second pipe body 20, which can be understood that, on one hand, the first pipe body 10 and the second pipe body 20 are connected and fixed by the heat exchange elements 30 to form a heat exchanger with stable structure; on the other hand, when the heating medium (in the embodiment of the present invention, the heating medium in the first heat exchanger 4 refers to the high temperature gas discharged from the exhaust pipe 51 of the gas turbine 5, and the heating medium in the second heat exchanger 6 refers to the steam with reduced temperature discharged from the medium outlet of the tesla turbine 2) flows in the heating medium channel, the heat carried in the heating medium can be more quickly conducted to the first pipe 10 through the plurality of heat exchange elements 30 on the inner wall of the first pipe 10, and then the heat is absorbed by the refrigerant (in the embodiment of the present invention, the refrigerant refers to the liquid medium in the housing 11) through the plurality of heat exchange elements 30 attached between the outer wall of the first pipe 10 and the inner wall of the second pipe 20. Therefore, the heat exchange areas of the heat exchangers in the refrigerant channels and the heating medium channels can be increased by the heat exchange elements 30, and the heat exchange efficiency of the heat exchangers can be improved.

The specific heat exchange process is as follows: the heat medium flows in the heat medium channel along the arrow direction in the figure, the refrigerant flows in the refrigerant channel along the other arrow direction in the figure, the flow direction of the heat medium is opposite to that of the refrigerant, and heat exchange is performed through the first pipe body 10 and the plurality of heat exchange elements 30 in the flow process of the heat medium and the refrigerant. At this time, the heat carried in the heating medium is conducted to the heat exchange element 30 through the first pipe body 10, and the heat is absorbed by the contact between the cooling medium flowing in the cooling medium channel and the heat exchange element 30.

It should be noted that, the heat exchange element 30 has an irregular shape, and the heat exchange medium can freely flow in the flow channel, so that the flow resistance can be reduced, and the pressure loss caused by the flow medium can be reduced; meanwhile, the heat exchanger also has a higher specific surface area, and the heat exchange area of the heat exchanger can be greatly increased, so that the heat exchange efficiency of the heat exchanger is improved; in addition, the heat exchanger can be more compact in structure due to the higher heat exchange efficiency.

Optionally, a gap is provided between any two adjacent heat exchange elements 30 in both the axial direction and the radial direction of the first tube body 10.

In order to further reduce the flow resistance of the heat exchanger, gaps are arranged between any two adjacent heat exchange elements 30 in the axial direction and the radial direction along the first pipe body 10, so that the heat exchange medium can flow more freely and randomly in the flow passage, and the pressure loss caused by the heat exchanger to the flow medium is further reduced.

Alternatively, the heat exchange element 30 may be shaped in a regular or irregular configuration.

Specifically, when the heat exchange element 30 has a regular shape, the heat exchange element 30 may be a corrugated plate, a fin plate, or a water drop shape with the shape of the heat exchange element in the direction of flow. As shown in fig. 4, if the heat exchange element is shaped like a water droplet in the flow direction, the flow resistance of the heat exchanger can be further reduced.

When the shape of the heat exchange element 30 is an irregular structure, the shape of the heat exchange element 30 can be coral or burr.

Optionally, the first tube body 10 and the second tube body 20 are concentrically arranged.

In the embodiment of the present invention, the first tube body 10 and the second tube body 20 are arranged coaxially, so that the structural stability of the heat exchanger can be improved, and the flow of the flowing medium in the flow channel can be ensured to be uniform.

Optionally, the heat exchange element 30 is irregularly coral-shaped in shape.

Here, an irregular coral shape is understood to mean that the heat exchange element 30 has irregular protrusions and depressions on the outer surface, and the outer shape is similar to coral. Therefore, the embodiment of the invention can further increase the heat exchange area, thereby further improving the heat exchange efficiency of the heat exchanger.

Optionally, the heat exchange element 30 is a metal heat exchange element, and the heat conductivity of the heat exchange element 30 is greater than or equal to 2000 watts/(meter kelvin).

In the embodiment of the present invention, the heat exchange element 30 should be a metal heat exchange element having high heat conductivity, for example, a heat conductivity of 2000 watts/(meter kelvin) or more, and the selected metal material may be, for example, stainless steel, aluminum, copper, or the like. On this basis, the metal material chosen should also be resistant to high temperatures, preferably stainless steel. Thus, the heat exchanger is not easy to damage, and the service life of the heat exchanger can be prolonged.

Alternatively, the height of the heat exchange element 30 in the radial direction of the tube body ranges between 0.010 micrometers and 10 micrometers.

For example, the height of the heat exchange element 30 in the radial direction of the first tube body 10 may range between 0.010 micrometers and 10 micrometers. For example, the length of the heat exchange element 30 in the circumferential direction of the first tube body 10 is 0.05 μm. In this way, the pressure loss of the heat exchanger to the flow medium can be further reduced by the heat exchange element of the micrometer scale.

Optionally, the cross-sectional area of the coolant channel and the cross-sectional area of the heating medium channel are equal.

In the embodiment of the invention, the cross sectional areas of the two heat exchange medium channels are set to be equal, so that the circulation volumes of the two heat exchange mediums are basically equal, and the heat balance of the two heat exchange mediums is easier to achieve during heat exchange.

Optionally, the heat exchanger further comprises N pipe bodies, the N pipe bodies are sleeved in sequence from the inner diameter to the large, the N pipe bodies are sleeved on the second pipe body, and N is a positive integer greater than or equal to 1; a plurality of heat exchange elements 30 are attached between the inner wall and the outer wall of the adjacent tube body.

Fig. 10 and 11 show the case where N is 2, i.e. the heat exchanger comprises a total of four tubes. When the heat exchanger comprises four tube bodies, four medium channels can be formed, and the four medium channels are used for respectively and alternately passing through the heating medium and the cooling medium. Thus, the number of the refrigerant channels is increased from one to two, and the number of the heat medium channels is also increased from one to two. The heat exchanger provided by the embodiment of the invention can further improve the heat exchange effect due to the increased medium channels.

It should be noted that the heat exchanger may further include three pipes or five pipes, etc., and may be flexibly set according to specific working conditions of the heat exchanger.

Optionally, the gap between two adjacent tubes is 0.01 micrometers to 2 millimeters.

It should be noted that, for the distance between two adjacent tube bodies, the gap between the two adjacent tube bodies is between 0.01 micrometers and 2 millimeters, the existing installation method such as welding and the like cannot be realized, but the preparation method of the heat exchanger disclosed by the embodiment of the invention is suitable for the fixed installation of the heat exchange element in the small-size gap.

Further, the gap between two adjacent tubes is 0.01 micrometers to 0.5 millimeters.

When the gap between two adjacent pipe bodies is not more than 0.5mm, the air flow between the two pipe bodies can generate an auxiliary surface layer effect, and the air can be forced to flow between the two pipe bodies in a laminar flow mode, so that three-dimensional flow such as turbulence or vortex flow can be reduced, and the pressure loss caused by flow resistance is reduced.

As shown in fig. 12, a method for manufacturing a heat exchanger includes:

s1, smearing and/or spraying attachment substances on the outer wall and the inner wall of the first pipe body.

Wherein, the specific steps of smearing and/or spraying the attachment matters on the outer wall and the inner wall of the first pipe body are as follows: the attached matter occupies the shape of the heat exchange element on the mold in advance, and when the attached matter falls on the pipe wall, the original mold occupies the hollow cavity left after the mold is pulled out, namely the shape of the heat exchange element.

The above-mentioned adherent substance is used for the purpose of prefilling, and therefore, the adherent substance should be a substance that can be rinsed off by a chemical agent. Optionally, the adherent material comprises at least one of gypsum, plastic, resin, or clay. Further, the attached matter is granular or powdery, and the diameter of the attached matter ranges from 0.01 micrometers to 2 millimeters.

And S2, spraying metal liquid on the outer wall and the inner wall of the first pipe body to infiltrate the metal liquid and fill the pores of the attached matter.

Optionally, the metal liquid contains flaky graphite powder, ceramic powder or diamond powder.

In order to further improve the heat exchange efficiency of the heat exchanger, flocculent graphite powder, ceramic powder or diamond powder can be added into the metal liquid. Taking graphite powder as an example, the specific steps are as follows: rubbing pyrolytic graphite with defects introduced, the surface of bulk graphite willTo produce flaky crystals, which contain a single layer of graphene, and a sufficient amount of flaky crystals are uniformly mixed into a metal liquid. Thus, the metal-graphene composite material is cooled and formed in S4, and the thermal conductivity of the metal-graphene composite material can reach as high as 10 ³ Watt/(meter kelvin) magnitude.

S3, before the metal liquid is solidified, placing the second pipe body outside the first pipe body, enabling the metal liquid on the outer wall of the first pipe body to be respectively connected with the outer wall of the first pipe body and the inner wall of the second pipe body after being solidified, and enabling the outer diameter of the first pipe body to be smaller than the inner diameter of the second pipe body.

Optionally, the first pipe body and the second pipe body are kept concentric with the central axis through the fixture, and the second pipe body is arranged outside the first pipe body.

S4, after the metal liquid is deposited and cooled and molded, the attached matter is washed away, and the heat exchange element with the regular or irregular appearance is obtained.

Optionally, the heat exchanger further comprises N pipe bodies, the N pipe bodies are sequentially sleeved on the second pipe body according to the order from the smaller inner diameter to the larger inner diameter, and N is a positive integer greater than or equal to 1; the method further comprises the steps of:

coating and/or spraying an attachment material on the outer wall of the inner tube in the two adjacent tube bodies;

spraying metal liquid on the outer wall of the inner pipe to infiltrate the metal liquid and fill the pores of the attached matter;

before solidifying the metal liquid, placing the outer tube of two adjacent tube bodies outside the inner tube, and respectively connecting the outer tube wall of the inner tube and the inner tube wall of the outer tube after solidifying the metal liquid on the outer tube wall of the inner tube;

and after the metal liquid is deposited and cooled to be formed, washing away the attached matter, so that a heat exchange element with a regular structure or an irregular structure is formed between the outer wall of the inner tube and the inner wall of the outer tube.

In the embodiment of the invention, the heat exchange element is prepared in a chemical molding mode, and has the advantages of good manufacturability, easiness in processing, low cost, good stability, capacity of realizing mass production and the like. Therefore, the preparation of the heat exchanger has higher manufacturability and better structural stability of the heat exchanger.

Various specific structural forms of the air-magnetic hybrid thrust bearing and the air-magnetic hybrid radial bearing, and specific control methods of each thrust bearing and each radial bearing during control of a tesla turbine, are described in detail below with reference to the accompanying drawings.

Example IV

Fig. 13 to 16 are schematic structural views of a foil type air-magnetic hybrid thrust bearing according to an embodiment of the present invention.

As shown in fig. 13 to 16, the foil type air-magnetic hybrid thrust bearing 5100 includes:

the first thrust plate 5101, the first thrust plate 5101 is fixedly connected to the rotating shaft 100;

and, a first stator 5102 and a second stator 5103 penetrating through the rotating shaft 100, wherein the first stator 5102 and the second stator 5103 are respectively arranged at two opposite sides of the first thrust plate 5101;

each of the first stator 5102 and the second stator 5103 includes a first magnetic bearing 5104 and a first foil bearing 5105, a plurality of first magnetic members are provided on the first magnetic bearing 5104 in a circumferential direction, and the first foil bearing 5105 is provided with a second magnetic member capable of generating magnetic force with the plurality of first magnetic members;

the first foil bearing 5105 is disposed between the first magnetic bearing 5104 and the first thrust plate 5101, and has a first gap 5106 with the first thrust plate 5101, and the first foil bearing 5105 can move in the axial direction of the rotating shaft 100 under the action of magnetic force between the first magnetic component and the second magnetic component.

In the embodiment of the present invention, the first gap 5106 and the first magnetic bearing 5104 are provided in the thrust bearing 5100, so that the thrust bearing 5100 forms a gas-magnetic hybrid thrust bearing.

When in operation, the gas bearing in the thrust bearing 5100 can work cooperatively with the first magnetic bearing 5104, and when the thrust bearing 5100 is in a stable working state, the support is realized by the gas bearing; while the thrust bearing 5100 is in an unstable operating state, the thrust bearing 5100 is controlled and responded to in time by means of the first magnetic bearing 5104.

Therefore, the embodiment of the invention can improve the dynamic performance and stability of the thrust bearing, particularly in a high-speed running state, has strong disturbance resistance, and further improves the bearing capacity of the thrust bearing. The thrust bearing provided by the embodiment of the invention can meet the requirements of a Tesla turbine with high rotating speed, such as a gas turbine or a gas turbine power generation combined set.

In the embodiment of the present invention, the outer diameters of the first thrust plate 5101, the first stator 5102 and the second stator 5103 may be equal, and the structures of the first stator 5102 and the second stator 5103 may be identical.

When the tesla turbine of the embodiment of the present invention is applied to a gas turbine or a gas turbine generator set, the first stator 5102 and the second stator 5103 may be connected with a housing of the gas turbine through a connection.

Optionally, the plurality of first magnetic components includes a plurality of first permanent magnets disposed circumferentially on the first magnetic bearing 5104;

alternatively, the plurality of first magnetic members include a plurality of first electromagnets circumferentially disposed on the first magnetic bearing 5104, each of the plurality of first electromagnets including a first magnetic core 51041 disposed on the first magnetic bearing 5104 and a first coil 51042 wound around the first magnetic core.

In the embodiment of the present invention, when the foil type air-magnetic hybrid thrust bearing 5100 only needs the magnetic component to provide magnetic force without magnetic control, the first magnetic component preferably selects the first permanent magnet; when the foil type air-magnetic hybrid thrust bearing 5100 requires both magnetic force and magnetic control, the first magnetic component is preferably a first electromagnet.

When the first magnetic member is a first electromagnet, a current is applied to the first coil 51042, so that the first magnetic core 51041 generates a magnetic force. The magnitude of the current supplied to the first coil 51042 is different, and the magnitude of the magnetic force generated by the first magnetic core 51041 is also different; the direction of current flowing through the first coil 51042 is different, and the magnetic poles of the first core 51041 are also different.

In the preferred embodiment of the present invention, the first magnetic core 51041 is formed by laminating a plurality of silicon steel sheets or silicon steel sheets, because the silicon steel sheets or silicon steel sheets have physical characteristics of high magnetic permeability, low eddy current loss, etc.

Optionally, the first magnetic bearing 5104 includes:

the first magnetic bearing seat 51043, the first magnetic bearing seat 51043 is opposite to the first thrust disc 5101, a plurality of first accommodating grooves 51044 are formed in the first magnetic bearing seat 51043 along the circumferential direction, a plurality of first magnetic components are arranged in the plurality of first accommodating grooves 51044, and magnetic poles of the plurality of first magnetic components face to one side where the first foil bearing 5105 is located;

the first end cap 51045, the first end cap 51045 is disposed on a side of the first magnetic bearing block 51043 remote from the first foil bearing 5105, and cooperates with the first foil bearing 5105 to secure the first magnetic component to the first magnetic bearing block 51043.

In the preferred embodiment of the present invention, the first magnetic bearing seat 51043 is formed by laminating a plurality of silicon steel sheets or silicon steel sheets, because the silicon steel sheets or silicon steel sheets have physical characteristics of high magnetic permeability, low eddy current loss, etc. The number of the first receiving grooves 51044 may be, but is not limited to, six or eight, and are uniformly disposed along the circumferential direction of the first magnetic bearing mount 51043. In this way, the magnetic force between the first magnetic bearing block 51043 and the first foil bearing 5105 can be more uniform and stable. The plurality of first magnetic members may be provided on the first magnetic bearing seat 51043 in other manners, which is not limited thereto. The material of the first end cap 51045 may be a non-magnetic material, preferably a duralumin material.

Optionally, the first foil bearing 5105 includes:

a first foil bearing mount 51051 fixedly connected to the first magnetic bearing mount 51043;

and a first foil 51052 and a second foil 51053 disposed on the first foil bearing support 51051, the first foil 51052 being mounted on the first foil bearing support 51051, the second foil 51053 being stacked on a side of the first foil 51052 adjacent to the first thrust plate 5101;

wherein the second foil 51053 is a flat foil, and the second magnetic component is disposed on the second foil 51053, so that the second foil 51053 can move in the axial direction of the rotating shaft 100 under the magnetic force of the first magnetic component and the second magnetic component; the first foil 51052 is an elastically deformable foil capable of being elastically deformed when the second foil 51053 is moved.

The material of the first foil bearing seat 51051 is a non-magnetic material, preferably a duralumin material. The first foil 51052 is an elastically deformable foil, and the first foil 51052 is preferably a stainless steel strip that is not magnetically permeable, because the magnetically permeable material is hard and brittle and is not suitable as an elastically deformable foil.

In the embodiment of the present invention, by setting the second foil 51053 as a flat foil, it is convenient to control the distance between the second foil 51053 and the first thrust plate 5101, or, in other words, to control the size of the first gap 5106. The first foil 51052 adopts a foil capable of elastically deforming, and serves to connect the second foil 51053 and the first foil bearing seat 51051, and can realize the purpose that the second foil 51053 can move along the axial direction of the rotating shaft 100 relative to the first foil bearing seat 51051.

Optionally, the first foil 51052 is an elastically deformable foil in a wavy shape, and the first foil 51052 is in an unsealed ring shape, and is provided with an opening, one end of the opening is a fixed end, the fixed end is fixed on the first foil bearing seat 51051, and the other end of the opening is a movable end;

wherein, when the second foil 51053 moves in the axial direction of the rotating shaft 100, the corrugations on the first foil 51052 expand or contract, and the movable end moves along the circumferential direction of the ring shape.

In the embodiment of the present invention, by providing the first foil 51052 as a waved elastically deformable foil, the second foil 51053 is pushed to move in the axial direction of the rotating shaft 100 by utilizing the stretching or shrinking characteristics of the waved patterns.

It should be noted that the shape of the first foil 51052 in the embodiment of the present invention is not limited to the wave shape, and other shapes capable of generating elastic deformation may be suitable for the first foil 51052 in the embodiment of the present invention.

Optionally, the second magnetic component comprises a first magnetic material disposed on a side surface of the second foil 51053 proximate to the first magnetic bearing 5104;

wherein the first magnetic material is distributed in a strip shape on the second foil 51053 to form a plurality of strip-shaped magnetic parts, and the plurality of strip-shaped magnetic parts are radial or annular;

Alternatively, the first magnetic means are distributed in a spot on the second foil 51053.

The material of the second foil 51053 is preferably a non-magnetic material, and after the surface of the second foil 51053 is covered with the first magnetic material, the first magnetic material may be covered with a ceramic coating. The second foil 51053 may be made by sintering ceramic nanopowders using 40% zirconia, 30% alpha alumina and 30% magnesium aluminate spinel.

If the surface of the second foil 51053 completely covers the first magnetic material, magnetic force generated between the first magnetic material and the first magnetic component is greatly increased, which easily causes deformation of the second foil 51053. In view of this, in the embodiment of the present invention, by spraying the first magnetic material on the surface of the second foil 51053, the first magnetic material is distributed in a stripe shape or a dot shape on the second foil 51053, so that the magnetic force generated between the first magnetic material and the first magnetic component can be controlled within a reasonable range, thereby avoiding the deformation of the second foil 51053 due to the excessive magnetic force.

Optionally, the foil-type air-magnetic hybrid thrust bearing 5100 further includes a first sensor 5107, and a sensor probe of the first sensor 5107 is disposed in the first gap 5106.

In the embodiment of the present invention, by providing the first sensor 5107, parameters at the first gap 5106, such as the air film pressure at the first gap 5106, etc., can be detected in real time. In this way, the first magnetic bearing 5104 can actively control the thrust bearing 5100 according to the detection result of the first sensor 5107, and control can be performed with high accuracy.

Optionally, the first sensor 5107 includes a first sensor cover 51071 and a first sensor probe 51072, a first end of the first sensor probe 51072 is connected to the first sensor cover 51071, the first sensor cover 51071 is fixed on the first magnetic bearing 5104, and through holes for the first sensor probe 51072 to pass through are provided on the first magnetic bearing 5104 and the first foil bearing 5105; the second end of the first sensor probe 51072 passes through the through holes in the first magnetic bearing 5104 and the first foil bearing 5105 and extends to the first gap 5106, and the second end of the first sensor probe 51072 is flush with the side of the first foil bearing 5105 adjacent to the first thrust plate 5101.

In the embodiment of the present invention, the first sensor 5107 can be more stably disposed on the first magnetic bearing 5104 by the structural form and the mounting manner of the first sensor 5107. The second end part of the first sensor probe 51072 is flush with one side of the first foil bearing 5105, which is close to the first thrust plate 5101, so that on one hand, the first sensor probe 51072 can be prevented from being touched by the first thrust plate 5101, and the first sensor probe 51072 can be protected; on the other hand, the air film in the first gap 5106 is not affected, and disturbance of the air film in the first gap 5106 is avoided.

Optionally, the first sensor 5107 is disposed between two adjacent first magnetic members.

In the embodiment of the present invention, at least one first sensor 5107 should be disposed on each stator, and preferably one first sensor 5107 is disposed, and the first sensor 5107 is preferably disposed between two adjacent first magnetic members.

Optionally, the first sensor 5107 is a combination of any one or more of:

a displacement sensor for detecting the position of the first thrust plate 5101;

a pressure sensor for detecting the gas film pressure at the first gap 5106;

a speed sensor for detecting the rotational speed of the first thrust disc 5101;

an acceleration sensor for detecting rotational acceleration of the first thrust plate 5101.

The following describes in detail a specific control method when the foil type air-magnetic hybrid thrust bearing (wherein the first magnetic component in the first magnetic bearing is an electromagnet) participates in the control process of the tesla turbine.

The embodiment of the invention provides a control method of a foil type air-magnetic hybrid thrust bearing, which comprises the following steps:

s511, opening the first magnetic bearings in the first stator and the second stator, and controlling the first thrust disc to move in the axial direction of the rotating shaft under the action of the magnetic force of the plurality of first magnetic components so that a first gap between the first thrust disc and the first foil bearing in the first stator is equal to a first gap between the first thrust disc and the first foil bearing in the second stator.

S512, after the rotating speed of the rotating shaft is accelerated to the working rotating speed, the first magnetic bearings in the first stator and the second stator are closed.

S513, when the Tesla turbine is stopped, the first magnetic bearings in the first stator and the second stator are started.

S514, after the rotating speed of the rotating shaft is reduced to zero, the first magnetic bearings in the first stator and the second stator are closed.

In the above process, after the first magnetic bearing is opened, the first thrust disc reaches a predetermined position between the first stator and the second stator under the action of the first magnetic bearing, and the first thrust disc and the end surfaces of the first stator and the second stator have first gaps.

With the rotation of the rotating shaft, the first thrust disc starts to rotate relative to the first stator and the second stator under the condition of being lubricated by the air flow in the first gap so as to prevent abrasion. The specific process for opening the first magnetic bearing is as follows: a current signal of a predetermined value is input to the first coil, and the first thrust disk reaches a predetermined position between the first stator and the second stator under the action of the first magnetic bearing.

With the increasing rotation speed of the rotating shaft, the rotation speed of the first thrust disc is synchronously increased, and when the rotation speed of the rotating shaft reaches the working rotation speed, the first thrust disc can be stabilized by the air film pressure generated by the air dynamic bearing of the thrust bearing (the air dynamic bearing forming the thrust bearing is formed by arranging a first gap between the first thrust disc and the first stator and between the first stator and the second stator), and then the first magnetic bearing can be closed.

When the Tesla turbine is stopped, the first thrust disk is decelerated along with the deceleration of the rotating shaft, and in order to keep the rotating shaft stable in the whole Tesla turbine stopping process, the first magnetic bearing is started when the Tesla turbine is stopped, and the first magnetic bearing is closed until the first thrust disk is completely stopped.

The embodiment of the invention also provides a control method of the foil type air-magnetic hybrid thrust bearing, which comprises the following steps:

s521, opening the first magnetic bearings in the first stator and the second stator, and controlling the first thrust disc to move in the axial direction of the rotating shaft under the action of the magnetic force of the first magnetic components so that a first gap between the first thrust disc and the first foil bearing in the first stator is equal to a first gap between the first thrust disc and the first foil bearing in the second stator.

S522, after the rotating speed of the rotating shaft is accelerated to a first preset value, the first magnetic bearings in the first stator and the second stator are closed.

S523, when the rotating speed of the rotating shaft is reduced to a second preset value, starting the first magnetic bearings in the first stator and the second stator.

S524, after the rotating speed of the rotating shaft is reduced to zero, the first magnetic bearings in the first stator and the second stator are closed.

With the increasing rotation speed of the rotating shaft, the rotation speed of the first thrust disc is synchronously increased, and when the rotation speed of the rotating shaft reaches a first preset value, for example, 5-30% of the rated rotation speed, the air film pressure generated by the air dynamic bearing of the thrust bearing (the air dynamic bearing forming the foil type air magnetic hybrid thrust bearing is formed by arranging a first gap between the first thrust disc and the first stator and between the first stator and the second stator) can stabilize the first thrust disc, and then the first magnetic bearing can be closed.

During a tesla turbine shutdown, the first thrust disk is decelerated along with the deceleration of the rotating shaft, and when the rotating speed of the rotating shaft is lower than a second preset value, for example, 5% to 30% of the rated rotating speed, the air film pressure generated by the air dynamic pressure bearing of the thrust bearing is also reduced along with the deceleration of the first thrust disk, so that the first magnetic bearing needs to be started to keep the first thrust disk stable, and the first magnetic bearing can be closed until the first thrust disk is completely stopped.

Optionally, the method further comprises:

when the load is applied to the first thrust disc, the first thrust disc moves in the axial direction of the rotating shaft under the action of the load, and a first gap between the first thrust disc and a first foil bearing in the first stator is not equal to a first gap between the first thrust disc and a first foil bearing in the second stator, the first magnetic bearings in the first stator and the second stator are opened;

the first magnetic bearings in the first stator and the second stator are closed when the first gap between the first thrust disc and the first foil bearing in the first stator is equal to the first gap between the first thrust disc and the first foil bearing in the second stator.

When a load is placed on the first thrust disc, such that the first gap between the first thrust disc and the first foil bearing of the first stator or the second stator becomes smaller and approaches the first foil bearing of the side, the first sensor (here the first sensor is preferably a pressure sensor) obtains a signal of an increase in air pressure, at which time the first magnetic bearing needs to be involved. The first magnetic bearing does not directly apply magnetic force to the first thrust disk to enable the first magnetic bearing to move towards the first foil bearing on the other side, but uses magnetic force to enable the first foil bearing on the other side to move away from the first thrust disk, so that a first gap between the first thrust disk and the first foil bearing on the other side is improved, the pressure on the side where the first gap is reduced is improved, the load weight on the first thrust disk is adapted, and the air flow pressure on the two first gaps is automatically redistributed. When the first thrust disc reaches a new equilibrium position, the first magnetic bearing stops working.

Specifically, if the first gap between the first thrust disc and the first foil bearing in the first stator is smaller than the first gap between the first thrust disc and the first foil bearing in the second stator, the first foil bearing in the second stator is controlled to move in the axial direction of the rotating shaft in the direction away from the first thrust disc under the action of magnetic forces between the plurality of first magnetic components and the second magnetic component.

And if the first gap between the first thrust disc and the first foil bearing in the second stator is smaller than the first gap between the first thrust disc and the first foil bearing in the first stator, controlling the first foil bearing in the first stator to move in the axial direction of the rotating shaft in the direction away from the first thrust disc under the action of magnetic force between the plurality of first magnetic components and the second magnetic component.

Optionally, when the load is applied to the first thrust disc, the first thrust disc moves in the axial direction of the rotating shaft under the action of the load, and the first gap between the first thrust disc and the first foil bearing in the first stator is not equal to the first gap between the first thrust disc and the first foil bearing in the second stator, the first magnetic bearing in the first stator and the second stator is turned on, including:

When the load is applied to the first thrust disc, the first thrust disc moves in the axial direction of the rotating shaft under the action of the load, and a first gap between the first thrust disc and a first foil bearing in the first stator is not equal to a first gap between the first thrust disc and a first foil bearing in the second stator, the first magnetic bearings in the first stator and the second stator are controlled to be opened at maximum power; or,

when the load is applied to the first thrust disc, the first thrust disc moves in the axial direction of the rotating shaft under the action of the load, and the first gap between the first thrust disc and the first foil bearing in the first stator is not equal to the first gap between the first thrust disc and the first foil bearing in the second stator, the first magnetic bearings in the first stator and the second stator are controlled to be opened in a stroboscopic manner according to a preset frequency.

When external impact disturbance occurs, the first thrust disc may quickly approach a first foil bearing on a certain side, which may cause the first gap on the certain side to be excessively small instantaneously, so that the local gas flow velocity at the first gap on the certain side approaches or even reaches the sonic velocity, and the shock wave is triggered to generate the air hammer self-excitation phenomenon. The generation of shock waves causes local gas flow disturbances and upsets, with a significant step drop in pressure as the fluid velocity changes between sonic to subsonic. In this case, the side first foil bearing is required to actively "dodge" the first thrust disc, thereby increasing the side first clearance to maintain the air flow velocity as far as possible in the subsonic region to maintain its normal fluid pressure. Specifically, it is necessary to control the first magnetic bearings on the first stator and the second stator simultaneously, so that the magnetic poles of the first magnetic bearings are excited with the same polarity, that is, the side with the reduced first gap generates a suction force for sucking back the side first foil bearing, and the side with the increased first gap generates a suction force for pulling back the first thrust disk. Thus, the magnetic force difference is generated by utilizing the difference of the magnetic force acting distances of the two sides, and the first thrust disc is pulled to enable the first gap between the first thrust disc and the first foil bearings of the two sides to be restored to be normal, so that the first thrust disc is returned to the balanced state again.

In the process, the advantages of the first magnetic bearing that the real-time control is convenient are utilized, and the factors of the unbalanced mass of the first thrust disc or the excessive deflection of the first thrust disc caused by the vortex of the first thrust disc and the like are actively balanced, so that the first thrust disc is fixed in a certain minimum range in the axial direction of the rotating shaft. In addition, in the acceleration process of the first thrust disk, the position (namely the linear velocity supersonic speed part) where the shock wave is generated can be accurately positioned, and the shock wave effect is balanced by controlling the current magnitude, the current direction and the like of the first magnetic bearing, so that the first magnetic bearing generates opposite force. And after the shock wave is stable, the control strategy of the first magnetic bearing is regulated again, and the first thrust disc is fixed in a certain minimum range in the most energy-saving mode.

In summary, the embodiment of the invention has the following beneficial effects:

firstly, the electromagnetic bearing and the gas bearing work cooperatively, so that the dynamic performance and stability of the bearing in a high-speed running state are improved, the disturbance resistance is high, and the bearing capacity of the bearing is further improved. Meanwhile, the electromagnetic bearing and the gas bearing adopt a parallel structure, so that the structure is simplified, the integration level is high, the processing, the manufacturing and the operation are easy, and the comprehensive performance of the bearing is improved. When the Tesla turbine is started or stopped, the thrust disc and the stator of the bearing can rotate in the bearing clearance by using the electromagnetic bearing, so that the low-speed performance of the bearing is improved, the service life of the bearing is prolonged, and the safety and reliability of the bearing and the whole system can be improved.

Secondly, compared with the traditional aerostatic and static hybrid thrust bearing adopting the combination of the aerostatic bearing and the aerodynamic bearing, the foil type aeromagnetic hybrid thrust bearing provided by the embodiment of the invention has the advantage of high response speed.

Thirdly, through setting up magnetic material on the foil, can make the foil moderate deformation through the attraction of electromagnetic bearing's magnetic pole, improve the highest pressure of lubricated air film one side in the bearing and prevent lubricated air current leakage, improve thrust disk and receive the ability that the disturbance eccentric hits the wall to bearing capacity has also been improved.

Fourthly, a pressure sensor with lower cost is adopted to collect the pressure change of the air film, and the deformation of the foil is controlled by a simple control method, so that higher rotor damping can be provided, and the stability of the rotor is improved. In addition, the control method is simple, and the processing precision requirement of the bearing is not high.

Example five

Fig. 17 to 23 are schematic structural diagrams of a groove-type air-magnetic hybrid thrust bearing according to an embodiment of the present invention.

As shown in fig. 17 to 23, the groove type air-magnetic hybrid thrust bearing 5200 includes:

the second thrust plate 5201, the second thrust plate 5201 is fixedly connected to the rotating shaft 100, and the second thrust plate 5201 is provided with a third magnetic component;

And a third stator 5202 and a fourth stator 5203 penetrating the rotating shaft 100, the third stator 5202 and the fourth stator 5203 being disposed on opposite sides of the second thrust disk 5201, respectively;

in the third stator 5202 and the fourth stator 5203, each stator includes a second magnetic bearing 5204, a plurality of fourth magnetic members capable of generating magnetic force with the third magnetic members are circumferentially provided on the second magnetic bearing 5204, a second gap 5206 is provided between the second magnetic bearing 5204 and the second thrust plate 5201, and the second thrust plate 5201 is capable of moving in the axial direction of the rotary shaft 100 by the magnetic force between the third magnetic members and the plurality of fourth magnetic members;

wherein, the end faces of the second thrust plate 5201 facing the third stator 5202 and the fourth stator 5203, or the end faces of the third stator 5202 and the fourth stator 5203 facing the second thrust plate 5201 are provided with second dynamic pressure generating grooves 5205.

In the embodiment of the invention, the second gap 5206 and the second magnetic bearing 5204 are arranged in the thrust bearing 5200, so that the thrust bearing 5200 forms a gas-magnetic hybrid thrust bearing.

When the thrust bearing 5200 works, the gas bearing in the thrust bearing 5200 and the second magnetic bearing 5204 can work cooperatively, and when the thrust bearing 5200 is in a stable working state, the support is realized by the gas bearing; while the thrust bearing 5200 is in an unstable working state, the thrust bearing 5200 is controlled and responded by the second magnetic bearing 5204 in time.

In the embodiment of the present invention, the outer diameters of the second thrust plate 5201, the third stator 5202 and the fourth stator 5203 may be equal, and the structures of the third stator 5202 and the fourth stator 5203 may be identical.

When the tesla turbine of the embodiment of the present invention is applied to a gas turbine, the third stator 5202 and the fourth stator 5203 may be connected to the casing of the gas turbine by a connection.

In the embodiment of the present invention, when the second thrust plate 5201 rotates, the flowing gas present in the second gap 5206 is pressed into the second dynamic pressure generating groove 5205, thereby generating pressure to achieve that the second thrust plate 5201 is held in a noncontact manner in the axial direction. The magnitude of the pressure generated by the second dynamic pressure generating grooves 5205 varies depending on the angle, groove width, groove length, groove depth, groove number, and flatness of the second dynamic pressure generating grooves 5205. The magnitude of the pressure generated by the second dynamic pressure generating grooves 5205 is also related to the rotational speed of the second thrust disk 5201 and the second gap 5206. The parameters of the second dynamic pressure generating grooves 5205 can be designed according to the actual conditions. The second dynamic pressure generating grooves 5205 may be formed on the third stator 5202 and the fourth stator 5203 by forging, rolling, etching, stamping, or the like, or the second dynamic pressure generating grooves 5205 may be formed on the second thrust plate 5201 by forging, rolling, etching, stamping, or the like.

Optionally, the plurality of fourth magnetic components includes a plurality of second permanent magnets disposed circumferentially on the second magnetic bearing 5204;

alternatively, the plurality of fourth magnetic members include a plurality of second electromagnets circumferentially disposed on the second magnetic bearing 5204, each of the plurality of second electromagnets including a second magnetic core 52041 disposed on the second magnetic bearing 5204 and a second coil 52042 wound on the second magnetic core 52041.

In the embodiment of the invention, when the groove type air-magnetic hybrid thrust bearing 5200 only needs the magnetic component to provide magnetic force without magnetic control, the fourth magnetic component is preferably a second permanent magnet; when the slot type air-magnetic hybrid thrust bearing 5200 requires both magnetic force and magnetic control, the fourth magnetic component is preferably a second electromagnet.

When the fourth magnetic member is a second electromagnet, a current is supplied to the second coil 52042, so that the second magnetic core 52041 generates a magnetic force. The magnitude of the current flowing through the second coil 52042 is different, and the magnitude of the magnetic force generated by the second magnetic core 52041 is also different; the direction of current flowing through the second coil 52042 is different, and the magnetic poles of the second core 52041 are also different.

In the preferred embodiment of the present invention, the second magnetic core 52041 may be formed by laminating a plurality of silicon steel sheets or silicon steel sheets, because the silicon steel sheets or silicon steel sheets have physical characteristics of high magnetic permeability, low eddy current loss, etc.

Optionally, the second magnetic bearing 5204 includes:

the second magnetic bearing seat 52043, the second magnetic bearing seat 52043 is opposite to the second thrust disk 5201, a plurality of second accommodating grooves 52044 are circumferentially arranged on the second magnetic bearing seat 52043, a plurality of fourth magnetic components are arranged in the plurality of second accommodating grooves 52044, and the magnetic poles of the plurality of fourth magnetic components face to one side where the second thrust disk 5201 is located;

second end cap 52045 and first clamping ring 52046, second end cap 52045 set up in the one side of second magnetic bearing frame 52043 that is kept away from second thrust disk 5201, and first clamping ring 52046 sets up in the one side of second magnetic bearing frame 52043 that is close to second thrust disk 5201, and second end cap 52045 cooperates with first clamping ring 52046, fixes a plurality of fourth magnetic component on second magnetic bearing frame 52043.

In the preferred embodiment of the present invention, the second magnetic bearing seat 52043 may be formed by stacking a plurality of silicon steel sheets or silicon steel sheets, because the silicon steel sheets or silicon steel sheets have physical characteristics of high magnetic permeability, low eddy current loss, etc. The number of the second receiving grooves 52044 may be, but is not limited to, six or eight, and is uniformly disposed along the circumferential direction of the second magnetic bearing seat 52043. In this way, the magnetic force between the second magnetic bearing 5204 and the second thrust disk 5201 can be made more uniform and stable. The plurality of fourth magnetic members may be provided on the second magnetic bearing block 52043 in other manners, which is not limited thereto. The material of the second end cap 52045 can be a non-magnetic material, preferably a duralumin material. The material of the first pressure ring 52046 can be a non-magnetic material, preferably a duralumin material.

In an embodiment of the present invention, the second dynamic pressure generating groove 5205 may be disposed on the first pressure ring 52046, and in order to facilitate the processing of the second dynamic pressure generating groove 5205, the first pressure ring 52046 may be made of a stainless steel material.

Optionally, the third magnetic component includes a second magnetic material (not shown in the figure) disposed on an end surface of the second thrust plate 5201 facing the third stator 5202 and the fourth stator 5203;

wherein the second magnetic material is distributed in a strip shape on the second thrust plate 5201 to form a plurality of strip-shaped magnetic parts, and the plurality of strip-shaped magnetic parts are radial or annular;

alternatively, the second magnetic members are distributed in a dot shape on the second thrust plate 5201.

In the embodiment of the present invention, the second magnetic material is distributed in a stripe shape or a dot shape on the second thrust disk 5201, so that the magnetic force generated between the second magnetic material and the fourth magnetic component can be controlled within a reasonable range.

Optionally, the second dynamic pressure generating grooves 5205 are arranged radially or concentrically, which is advantageous for more uniformly distributing the air film in the second gap 5206.

Optionally, the second dynamic pressure generating groove 5205 includes a first spiral groove 52051 and a second spiral groove 52052, the first spiral groove 52051 surrounds the second spiral groove 52052, the spiral directions of the first spiral groove 52051 and the second spiral groove 52052 are opposite, and one end of the first spiral groove 52051 near the second spiral groove 52052 is connected or disconnected with one end of the second spiral groove 52052 near the first spiral groove 52051.

Wherein, the distance from the end of the first spiral groove 52051 near the second spiral groove 52052 to the axle center of the rotating shaft 100 is equal to the distance from the end of the first spiral groove 52051 near the second spiral groove 52052 to the outer peripheral edge of the third stator 5202 or the fourth stator 5203 or the second thrust plate 5201. Alternatively, the distance from the end of the second spiral groove 52052 close to the first spiral groove 52051 to the shaft center of the rotary shaft 100 is equal to the distance from the end of the second spiral groove 52052 close to the first spiral groove 52051 to the outer peripheral edge of the third stator 5202 or the fourth stator 5203 or the second thrust plate 5201.

In the embodiment of the present invention, by adopting the above-mentioned arrangement manner of the second dynamic pressure generating grooves 5205, the second thrust disc 5201 can be held in a non-contact manner in a desired manner in the case that the rotating shaft 100 rotates in the forward direction or in the reverse direction, so that the rotating shaft 100 has the advantages of high load capacity and good stability.

Optionally, in the third stator 5202 and the fourth stator 5203, a first static pressure air inlet throttle hole 5208 is further provided on each stator, one end of the first static pressure air inlet throttle hole 5208 is communicated with the second gap 5206, and the other end of the first static pressure air inlet throttle hole 5208 is connected with an external air source for conveying the external air source into the second gap 5206.

In the embodiment of the present invention, by providing the first static pressure air inlet orifice 5208, a aerostatic bearing may be formed, so that the thrust bearing 5200 may form a hybrid aerostatic-magnetic thrust bearing. The flow diameter of the first static pressure air inlet orifice 5208 can be adjusted according to actual working conditions such as air flow requirements.

Optionally, in the third stator 5202 and the fourth stator 5203, a plurality of first static pressure air intake orifices 5208 are disposed on each stator, and the plurality of first static pressure air intake orifices 5208 are disposed at intervals along the circumferential direction of the stator.

In the embodiment of the present invention, the plurality of first static pressure air intake orifices 5208 are arranged at intervals along the circumferential direction of the stator, preferably at uniform intervals along the circumferential direction of the stator. In this way, it is advantageous to make the gas film pressure in the second gap 5206 more uniform.

Optionally, in the third stator 5202 and the fourth stator 5203, a distance from the first static pressure air intake orifice 5208 to the axial center of the rotating shaft 100 is greater than or equal to a distance from the first static pressure air intake orifice 5208 to the outer peripheral edge of the stator.

In the embodiment of the present invention, the above-mentioned first static pressure air inlet orifice 5208 is arranged in a manner that the aerostatic bearing is more stable, and if the static pressure air inlet orifice is too close to the axis of the rotating shaft 100, the air film cannot be effectively distributed over the end face of the whole second thrust disc 5201 in time, so that the rotation of the second thrust disc 5201 is not stable enough. Preferably, the distance from the first static pressure intake orifice 5208 to the axial center of the rotary shaft 100 is equal to the distance from the first static pressure intake orifice 5208 to the outer peripheral edge of the stator.

Optionally, the groove type air-magnetic hybrid thrust bearing 5200 further includes a second sensor 5207, and a sensor probe of the second sensor 5207 is disposed in the second gap 5206.

In the embodiment of the invention, by arranging the second sensor 5207, parameters at the second gap 5206, such as the air film pressure at the second gap 5206, and the like, can be detected in real time. In this way, the second magnetic bearing 5204 can actively control the thrust bearing 5200 according to the detection result of the second sensor 5207, and can achieve higher accuracy of control.

Optionally, the second sensor 5207 includes a second sensor cover 52071 and a second sensor probe 52072, a first end of the second sensor probe 52072 is connected to the second sensor cover 52071, the second sensor cover 52071 is fixed on the second magnetic bearing 5204, and a through hole for the second sensor probe 52072 to pass through is provided on the second magnetic bearing 5204; the second end of the second sensor probe 52072 passes through the through hole in the second magnetic bearing 5204 and extends to the second gap 5206, and the second end of the second sensor probe 52072 is flush with the side of the second magnetic bearing 5204 adjacent to the second thrust disk 5201.

In the embodiment of the present invention, the second sensor 5207 can be more stably disposed on the second magnetic bearing 5204 by the structural form and the mounting manner of the second sensor 5207. In addition, the second end of the second sensor probe 52072 is flush with the side of the second magnetic bearing 5204, which is close to the second thrust plate 5201, so that on one hand, the second sensor probe 52072 can be prevented from being touched by the second thrust plate 5201, thereby being beneficial to protecting the second sensor probe 52072; on the other hand, the air film in the second gap 5206 is not affected, and the air film in the second gap 5206 is prevented from being disturbed.

Optionally, the second sensor 5207 is disposed between two adjacent fourth magnetic components.

In the embodiment of the present invention, at least one second sensor 5207, preferably one second sensor 5207, should be provided on each stator, and the second sensor 5207 is preferably provided between two adjacent fourth magnetic members.

Optionally, the second sensor 5207 is a combination of any one or more of the following:

a displacement sensor for detecting the position of the second thrust plate 5201;

a pressure sensor for detecting the gas film pressure at the second gap 5206;

a speed sensor for detecting the rotational speed of the second thrust plate 5201;

and an acceleration sensor for detecting rotational acceleration of the second thrust plate 5201.

The following describes in detail a specific control method when the groove type air-magnetic hybrid thrust bearing (wherein the fourth magnetic component in the second magnetic bearing is an electromagnet) participates in the control process of the tesla turbine.

The embodiment of the invention provides a control method of a groove type air-magnetic hybrid thrust bearing, which comprises the following steps:

s531, opening second magnetic bearings in the third stator and the fourth stator, and controlling the second thrust disk to move in the axial direction of the rotating shaft under the action of magnetic force between the third magnetic component and the plurality of fourth magnetic components so that the difference value between a second gap between the second thrust disk and the second magnetic bearings in the third stator and a second gap between the second thrust disk and the second magnetic bearings in the fourth stator is smaller than or equal to a preset value.

S532, after the rotating speed of the rotating shaft is accelerated to the working rotating speed, the second magnetic bearings in the third stator and the fourth stator are closed.

And S533, when the Tesla turbine is stopped, opening the second magnetic bearings in the third stator and the fourth stator.

S534, after the rotating speed of the rotating shaft is reduced to zero, the second magnetic bearings in the third stator and the fourth stator are closed.

In the above process, after the second magnetic bearing is opened, the second thrust disc reaches a predetermined position between the third stator and the fourth stator under the action of the second magnetic bearing, and the second thrust disc and the end surfaces of the third stator and the fourth stator have second gaps.

With the rotation of the rotating shaft, the second thrust disc starts to rotate relative to the third stator and the fourth stator under the condition of being lubricated by the air flow in the second gap so as to prevent abrasion. The specific process of opening the second magnetic bearing is as follows: a current signal of a preset value is input to the second coil, and the second thrust disk reaches a preset position between the third stator and the fourth stator under the action of the second magnetic bearing.

The rotation speed of the second thrust disc is synchronously increased along with the increasing of the rotation speed of the rotating shaft, and when the rotation speed of the rotating shaft reaches the working rotation speed, the air film pressure generated by the air dynamic bearing of the thrust bearing (the air dynamic bearing forming the thrust bearing by arranging a second gap between the second thrust disc and the third stator and the fourth stator) can stabilize the second thrust disc, and then the second magnetic bearing can be closed.

When the Tesla turbine is stopped, the second thrust disk is decelerated along with the deceleration of the rotating shaft, and in order to keep the rotating shaft stable in the whole Tesla turbine stopping process, the second magnetic bearing is started when the Tesla turbine is stopped, and the second magnetic bearing is closed until the second thrust disk is completely stopped.

The embodiment of the invention also provides a control method of the groove type air-magnetic hybrid thrust bearing, which comprises the following steps:

s541, opening second magnetic bearings in the third stator and the fourth stator, and controlling the second thrust disk to move in the axial direction of the rotating shaft under the action of magnetic force between the third magnetic component and the plurality of fourth magnetic components, so that a difference between a second gap between the second thrust disk and the second magnetic bearings in the third stator and a second gap between the second thrust disk and the second magnetic bearings in the fourth stator is smaller than or equal to a preset value.

S542, after the rotating speed of the rotating shaft is accelerated to a first preset value, the second magnetic bearings in the third stator and the fourth stator are closed.

S543, when the rotating speed of the rotating shaft is reduced to a second preset value, starting the second magnetic bearings in the third stator and the fourth stator.

S544, after the rotating speed of the rotating shaft is reduced to zero, the second magnetic bearings in the third stator and the fourth stator are closed.

In the above process, after the second magnetic bearing is opened, the second thrust disc reaches a predetermined position between the third stator and the fourth stator under the action of the second magnetic bearing, and the second thrust disc and the end surfaces of the third stator and the fourth stator have second gaps. With the rotation of the rotating shaft, the second thrust disc starts to rotate relative to the third stator and the fourth stator under the condition of being lubricated by the air flow in the second gap so as to prevent abrasion. The specific process of opening the second magnetic bearing is as follows: a current signal of a preset value is input to the second coil, and the second thrust disk reaches a preset position between the third stator and the fourth stator under the action of the second magnetic bearing.

With the increasing rotation speed of the rotating shaft, the rotation speed of the second thrust disc is synchronously increased, and when the rotation speed of the rotating shaft reaches a second preset value, for example, 5-30% of the rated rotation speed, the second thrust disc can be stabilized by the air film pressure generated by the air dynamic bearing of the thrust bearing (the air dynamic bearing forming the groove type air-magnetic hybrid thrust bearing is formed by arranging a second gap between the second thrust disc and the third stator and the fourth stator), and then the second magnetic bearing can be closed.

During the stop of the tesla turbine, the second thrust disk is decelerated along with the deceleration of the rotating shaft, and when the rotating speed of the rotating shaft is lower than a second preset value, for example, 5% to 30% of the rated rotating speed, the air film pressure generated by the air dynamic pressure bearing of the thrust bearing is also reduced along with the deceleration of the second thrust disk, so that the second magnetic bearing needs to be started to keep the second thrust disk stable, and the second magnetic bearing can be closed until the second thrust disk is completely stopped.

Optionally, the method further comprises:

when the load is loaded on the second thrust disc, the second thrust disc moves in the axial direction of the rotating shaft under the action of the load, and the difference value between a second gap between the second thrust disc and a second magnetic bearing in the third stator and a second gap between the second thrust disc and a second magnetic bearing in the fourth stator is larger than a preset value, the second magnetic bearing in the third stator or the fourth stator is started;

and closing the second magnetic bearings in the third stator or the fourth stator when a difference between a second gap between the second thrust disc and the second magnetic bearings in the third stator and a second gap between the second thrust disc and the second magnetic bearings in the fourth stator is less than or equal to a predetermined value.

When a load is placed on the second thrust disk, the second gap between the second thrust disk and the second magnetic bearing of the third stator or the fourth stator becomes smaller to approach the second magnetic bearing on the side, the second sensor (the second sensor here is preferably a pressure sensor) obtains a signal of an increase in air pressure, at which time the second magnetic bearing needs to be involved in operation. The second magnetic bearing acts on the second thrust disk by magnetic force to move the second thrust disk to the second magnetic bearing at the other side, and the second magnetic bearing stops working after the second thrust disk reaches a new balance position.

Specifically, if the second gap between the second thrust disc and the second magnetic bearing in the third stator is smaller than the second gap between the second thrust disc and the second magnetic bearing in the fourth stator, and the difference between the second gap between the second thrust disc and the second magnetic bearing in the third stator and the second gap between the second thrust disc and the second magnetic bearing in the fourth stator is greater than a predetermined value, the second magnetic bearing in the fourth stator is controlled to enable the second thrust disc to move in the axial direction of the rotating shaft in the direction away from the fourth stator under the action of magnetic force between the third magnetic component and the plurality of fourth magnetic components.

And if the second gap between the second thrust disc and the second magnetic bearing in the fourth stator is smaller than the second gap between the second thrust disc and the second magnetic bearing in the third stator, and the difference between the second gap between the second thrust disc and the second magnetic bearing in the third stator and the second gap between the second thrust disc and the second magnetic bearing in the fourth stator is larger than a preset value, controlling the second magnetic bearing in the third stator to enable the second thrust disc to move in the axial direction of the rotating shaft in the direction far away from the third stator under the action of magnetic force between the third magnetic component and the fourth magnetic components.

Optionally, when the load is applied to the second thrust disc, the second thrust disc moves in the axial direction of the rotating shaft under the action of the load, and a difference between a second gap between the second thrust disc and the second magnetic bearing in the third stator and a second gap between the second thrust disc and the second magnetic bearing in the fourth stator is greater than a predetermined value, the second magnetic bearing in the third stator or the fourth stator is turned on, including:

when the load is applied to the second thrust disc, the second thrust disc moves in the axial direction of the rotating shaft under the action of the load, and the difference between the second gap between the second thrust disc and the second magnetic bearing in the third stator and the second gap between the second thrust disc and the second magnetic bearing in the fourth stator is larger than a preset value, the second magnetic bearing in the third stator or the fourth stator is controlled to be opened at the maximum power; or,

when the load is applied to the second thrust disc, the second thrust disc moves in the axial direction of the rotating shaft under the action of the load, and the difference between the second gap between the second thrust disc and the second magnetic bearing in the third stator and the second gap between the second thrust disc and the second magnetic bearing in the fourth stator is larger than a preset value, the second magnetic bearing in the third stator or the fourth stator is controlled to be opened in a stroboscopic mode according to preset frequency.

When external impact disturbance occurs, the second thrust disc may quickly approach to the second magnetic bearing on a certain side, so that the second gap on the certain side may be excessively small instantaneously, and the local gas flow velocity at the second gap on the certain side approaches to or even reaches the sonic velocity, thereby triggering shock waves to generate the air hammer self-excitation phenomenon. The generation of shock waves causes local gas flow disturbances and upsets, with a significant step drop in pressure as the fluid velocity changes between sonic to subsonic. In this case, it is necessary to control the second magnetic bearings in the third stator or the fourth stator to be turned on at the maximum power, or to control the second magnetic bearings in the third stator or the fourth stator to be turned on in turn in a stroboscopic manner at a preset frequency to provide a damping effect on the disturbance, thereby effectively suppressing the external disturbance. After the second thrust disk returns to the equilibrium state, the second magnetic bearing stops operating.

In the embodiment of the present invention, when the electromagnetic bearing (the electromagnetic bearing is formed as the fourth magnetic component in the second magnetic bearing) and the hydrostatic gas bearing (the hydrostatic gas bearing is formed as the first hydrostatic air intake orifice provided in the third stator and the fourth stator) are simultaneously provided, the electromagnetic bearing and the hydrostatic gas bearing may be mutually spare, and when one of them fails or fails to satisfy the opening condition, the other may serve as a spare bearing. For example, in the case of detecting a failure of the electromagnetic bearing, the external air source is controlled to be turned on to perform a corresponding action instead of the electromagnetic bearing, thereby improving the safety and reliability of the bearing.

In the embodiment of the present invention, in the case where the electromagnetic bearing and the aerostatic bearing are provided at the same time, the step of "opening the aerostatic bearing in the thrust bearing to move the thrust disc of the thrust bearing to the preset axial position" may include the following implementation modes:

opening a second magnetic bearing of the third stator and the fourth stator; and/or starting an external gas source, and conveying gas to the second gap through the first static pressure inlet orifice;

and controlling the second thrust disc to move in the axial direction of the rotating shaft under the action of magnetic force between the third magnetic component and the fourth magnetic component and/or the pushing action of the gas so that the difference value between the second gap between the second thrust disc and the second magnetic bearing in the third stator and the second gap between the second thrust disc and the second magnetic bearing in the fourth stator is smaller than or equal to the preset value.

In the process, the advantages of the second magnetic bearing that the real-time control is convenient are utilized, and the factors of the unbalanced mass of the second thrust disk or excessive deflection of the second thrust disk caused by the vortex of the second thrust disk and the like are actively balanced, so that the second thrust disk is fixed in a certain minimum range in the axial direction of the rotating shaft. In addition, in the acceleration process of the second thrust disk, the position (namely the linear velocity supersonic speed part) where the shock wave is generated can be accurately positioned, and the second magnetic bearing generates opposite force to balance the shock wave action by controlling the current magnitude, the direction and the like of the second magnetic bearing. And after the shock wave is stable, the control strategy of the second magnetic bearing is regulated again, and the second thrust disc is fixed in a certain minimum range in the most energy-saving mode.

firstly, the electromagnetic bearing and the gas bearing work cooperatively, so that the dynamic performance and stability of the bearing in a high-speed running state are improved, the disturbance resistance is high, and the bearing capacity of the bearing is further improved. Meanwhile, the electromagnetic bearing and the gas bearing adopt a parallel structure, so that the structure is simplified, the integration level is high, the processing, the manufacturing and the operation are easy, and the comprehensive performance of the bearing is improved. When the Tesla turbine is started or stopped, the thrust disc and the stator of the bearing can rotate in the second gap by using the electromagnetic bearing, so that the low-speed performance of the bearing is improved, the service life of the bearing is prolonged, and the safety and reliability of the bearing and the whole system can be improved.

Secondly, compared with the traditional aerostatic and static hybrid thrust bearing adopting the combination of the aerostatic bearing and the aerodynamic bearing, the groove type aeromagnetic hybrid thrust bearing provided by the embodiment of the invention has the advantage of high response speed.

Thirdly, the aerostatic bearing is added to form a groove type dynamic static pressure-magnetic hybrid thrust bearing, under the condition that the electromagnetic bearing and the aerostatic bearing are simultaneously arranged, the bearing capacity of the bearing is further increased, the electromagnetic bearing and the aerostatic bearing can be mutually reserved, and under the condition that one side fails or cannot meet the opening condition, the other side can serve as a spare bearing to play the same role. For example, when a fault of the electromagnetic bearing is detected, the control system controls the aerostatic bearing to be opened to replace the electromagnetic bearing to execute corresponding actions, so that the safety and the reliability of the bearing are improved.

Example six

Fig. 24 to 29 are schematic structural views of a foil type air-magnetic hybrid radial bearing according to an embodiment of the present invention.

As shown in fig. 24 to 29, the foil type air-magnetic hybrid radial bearing 6100 includes:

the third magnetic bearing 6101 is sleeved on the rotating shaft 100, and a plurality of fifth magnetic components are arranged on the third magnetic bearing 6101 along the circumferential direction;

the second foil bearing 6102 is sleeved on the rotating shaft 100 and is positioned between the third magnetic bearing 6101 and the rotating shaft 100, and a sixth magnetic component capable of generating magnetic force with the plurality of fifth magnetic components is arranged on the second foil bearing 6102;

wherein, a third gap 6103 is provided between the second foil bearing 6102 and the rotating shaft 100, and the second foil bearing 6102 can move in the radial direction of the rotating shaft 100 under the magnetic force of a plurality of fifth magnetic members and sixth magnetic members.

In the embodiment of the present invention, the radial bearing 6100 is formed as a gas-magnetic hybrid radial bearing by providing the third gap 6103 and the third magnetic bearing 6101 in the radial bearing 6100.

When the radial bearing 6100 works, the gas bearing in the radial bearing 6100 and the third magnetic bearing 6101 can work cooperatively, and when the radial bearing 6100 is in a stable working state, the support is realized by means of the gas bearing; while when the radial bearing 6100 is in an unstable operation state, the radial bearing 6100 is controlled and responded by the third magnetic bearing 6101 in time.

Therefore, the embodiment of the invention can improve the dynamic performance and stability of the radial bearing, particularly in a high-speed running state, has strong disturbance resistance, and further improves the bearing capacity of the radial bearing. The radial bearing of the embodiment of the invention can meet the requirements of a Tesla turbine with high rotating speed, such as a gas turbine or a gas turbine power generation unit.

In the embodiment of the invention, the rotating shaft 100 may be formed by laminating a plurality of silicon steel sheets or silicon steel sheets due to the physical characteristics of high magnetic permeability, low eddy current loss and the like of the silicon steel sheets or the silicon steel sheets.

Optionally, the plurality of fifth magnetic components includes a plurality of third permanent magnets, the plurality of third permanent magnets being circumferentially disposed on the third magnetic bearing 6101;

alternatively, the plurality of fifth magnetic components include a plurality of third electromagnets circumferentially disposed on the third magnetic bearing 6101, each of the plurality of third electromagnets including a third magnetic core 61011 disposed on the third magnetic bearing 6101 and a third coil 61012 wound around the third magnetic core 61011.

In the embodiment of the present invention, when the foil type air-magnetic hybrid radial bearing 6100 only needs the magnetic component to provide magnetic force without magnetic control, the fifth magnetic component preferably uses the third permanent magnet; when the foil type air-magnetic hybrid thrust bearing requires both magnetic force and magnetic control, the fifth magnetic component is preferably a third electromagnet.

When the fifth magnetic component is the third electromagnet, current is applied to the third coil 61012, so that the third magnetic core 61011 can generate magnetic force. The magnitude of the current flowing through the third magnetic core 61012 is different, and the magnitude of the magnetic force generated by the third magnetic core 61011 is also different; the direction of current flowing through the third coil 61012 is different, and the magnetic poles of the third core 61011 are also different.

In the preferred embodiment of the present invention, the third magnetic core 61011 may be formed by laminating a plurality of silicon steel sheets or silicon steel sheets, because the silicon steel sheets or silicon steel sheets have physical characteristics of high magnetic permeability, low eddy current loss, and the like.

Optionally, the third magnetic bearing 6101 includes:

the third magnetic bearing seat 61013, the third magnetic bearing seat 61013 is sleeved on the rotating shaft 100, a plurality of third containing grooves 61014 are circumferentially arranged on the third magnetic bearing seat 61013, a plurality of fifth magnetic members are arranged in the third containing grooves 61014, and the magnetic poles of the fifth magnetic members face to the side where the second foil bearing 6102 is located;

a first bearing shell 61015 sleeved outside the third magnetic bearing base 61013;

a first bearing sleeve 61016 sleeved between the third magnetic bearing support 61013 and the second foil bearing 6102;

and a third end cover 61017 and a fourth end cover 61018 provided at both ends of the first bearing housing 61015, respectively;

The first bearing housing 61016, the third end cap 61017, and the fourth end cap 61018 cooperate to fix the plurality of fifth magnetic members to the third magnetic bearing housing 61013.

In the preferred embodiment of the present invention, the third magnetic bearing 61013 may be formed by stacking a plurality of silicon steel sheets or silicon steel sheets, because the silicon steel sheets or silicon steel sheets have physical characteristics of high magnetic permeability, low eddy current loss, etc. The number of the third receiving grooves 61014 may be, but not limited to, six or eight, and are uniformly arranged along the circumferential direction of the third magnetic bearing support 61013. In this way, the magnetic force between the third magnetic bearing 6101 and the second foil bearing 6102 can be made more uniform and stable. The plurality of fifth magnetic members may be provided on the third magnetic bearing base 61013 in other manners, which is not limited thereto. The material of the third end cap 61017 and the fourth end cap 61018 may both be a non-magnetic material, preferably a duralumin material. The material of the first bearing housing 61016 may be a non-magnetic material, preferably a duralumin material. The material of the first bearing housing 61015 may be a non-magnetic material, preferably a duralumin material.

Optionally, the second foil bearing 6102 includes a third foil 61021 and a fourth foil 61022, where the third foil 61021 is mounted on the first bearing sleeve 61016, and the fourth foil 61022 is stacked on a side of the third foil 61021 near the rotating shaft 100;

The fourth foil 61022 is a flat foil, and the sixth magnetic member is disposed on the fourth foil 61022, so that the fourth foil 61022 can move in the radial direction of the rotating shaft 100 under the magnetic force of the plurality of fifth magnetic members and the sixth magnetic member; the third foil 61021 is an elastically deformable foil that can be elastically deformed when the fourth foil 61022 is moved.

Among these, the third foil 61021 is preferably a stainless steel strip that is not magnetically conductive, since the material of the magnetically conductive material is hard and brittle and is not suitable as an elastically deformable foil.

In the embodiment of the present invention, by setting the fourth foil 61022 as a flat foil, it is convenient to control the distance between the fourth foil 61022 and the rotation shaft 100, or, it is convenient to control the size of the third gap 6103.

Optionally, the third foil 61021 is an elastically deformable foil that is wavy, and the third foil 61021 is an unsealed ring, and is provided with an opening, one end of the opening is a fixed end, the fixed end is fixed on the first bearing sleeve 61016, and the other end of the opening is a movable end;

when the fourth foil 61022 moves in the radial direction of the rotation shaft 100, the corrugations on the third foil 61021 extend or contract, and the movable end moves along the circumferential direction of the ring.

In the embodiment of the present invention, by arranging the third foil 61021 as an elastically deformable foil in a wave shape, the fourth foil 61022 is pushed to move in the radial direction of the rotation shaft 100 by utilizing the expansion or contraction characteristics of the wave pattern.

It should be noted that the shape of the third foil 61021 in the embodiment of the present invention is not limited to the wave shape, and other shapes capable of generating elastic deformation may be applied to the third foil 61021 in the embodiment of the present invention.

Optionally, the sixth magnetic component comprises a third magnetic material 61023 provided on a side surface of the fourth foil 61022 adjacent the first bearing sleeve 61016;

the third magnetic material 61023 is distributed on the fourth foil 61022 in a stripe shape to form a plurality of stripe-shaped magnetic portions, and the length direction of the plurality of stripe-shaped magnetic portions is parallel to the axis direction of the rotating shaft 100;

alternatively, the third magnetic means are distributed in a spot on the fourth foil 61022.

The material of the fourth foil 61022 is preferably a non-magnetic material, and after the surface of the fourth foil 61022 is covered with the third magnetic material 61023, the third magnetic material 61023 may be covered with a ceramic coating. The fourth foil 61022 may be made by sintering ceramic nano-powders using 40% zirconia, 30% alpha alumina and 30% magnesium aluminate spinel.

If the surface of the fourth foil 61022 completely covers the third magnetic material 61023, the magnetic force generated between the third magnetic material 61023 and the first magnetic member is greatly increased, which easily causes deformation of the fourth foil 61022. In view of this, in the embodiment of the present invention, by spraying the third magnetic material 61023 on the surface of the fourth foil 61022, the third magnetic material 61023 is distributed in a stripe shape or a dot shape on the fourth foil 61022, so that the magnetic force generated between the third magnetic material 61023 and the first magnetic member can be controlled within a reasonable range, thereby avoiding deformation of the fourth foil 61022 due to excessive magnetic force.

Optionally, the foil-type air-magnetic hybrid radial bearing 6100 further includes a plurality of third sensors 6104 disposed at intervals along the circumferential direction of the third magnetic bearing 6101, where each third sensor 6104 includes a third sensor cover 61041 and a third sensor probe 61042, a first end of the third sensor probe 61042 is connected to the third sensor cover 61041, the third sensor cover 61041 is fixed to the third magnetic bearing 6101, and through holes for the third sensor probe 61042 to pass through are provided in the first bearing shell 61015, the third magnetic bearing support 61013, and the first bearing sleeve 61016; the second end of the third sensor probe 61042 passes through the through holes in the first bearing shell 61015, the third magnetic bearing support 61013, and the first bearing sleeve 61016, and extends into the gap between the first bearing sleeve 61016 and the third foil 61021, and the second end of the third sensor probe 61042 is flush with the side of the first bearing sleeve 61016 that is close to the third foil 61021.

In the embodiment of the present invention, by providing the third sensor 6104, the gas pressure parameter at the third foil 61021 can be detected in real time. In this way, the third magnetic bearing 6101 can actively control the radial bearing 6100 according to the detection result of the third sensor 6104, and can achieve high accuracy of control.

In the embodiment of the present invention, the third sensor 6104 can be more stably disposed on the third magnetic bearing 6101 by the structural form and the mounting manner of the third sensor 6104 described above. In addition, the second end of the third sensor probe 61042 is flush with the side of the first bearing sleeve 61016 near the third foil 61021, so that on one hand, the third sensor probe 61042 can be prevented from being touched by the third foil 61021, thereby being beneficial for protecting the third sensor probe 61042; on the other hand, the air film in the third gap 6103 is not affected, and disturbance of the air film in the third gap 6103 is avoided.

Optionally, among the plurality of third sensors 6104, each third sensor 6104 is disposed between two adjacent fifth magnetic members, respectively.

In the embodiment of the present invention, the number of the third sensors 6104 may be the same as the number of the fifth magnetic members, each third sensor 6104 is disposed between two adjacent fifth magnetic members, and each third sensor 6104 is preferably disposed in the middle of the third magnetic bearing 6101. Further, in the embodiment of the present invention, in addition to the third sensor 6104 for detecting the gas pressure parameter at the third foil 61021, a displacement sensor for detecting the position of the rotation shaft, or a speed sensor for detecting the rotation speed of the rotation shaft, or an acceleration sensor for detecting the rotation acceleration of the rotation shaft, or the like may be provided.

The following describes in detail a specific control method when the foil type air-magnetic hybrid radial bearing (wherein the fifth magnetic component in the third magnetic bearing is an electromagnet) participates in the control process of the tesla turbine.

The embodiment of the invention provides a control method of a foil type air-magnetic hybrid radial bearing, which comprises the following steps:

s611, starting the third magnetic bearing, and controlling the rotating shaft to move in the radial direction of the rotating shaft under the action of the magnetic force of the plurality of fifth magnetic components so as to enable the rotating shaft to move to a preset radial position.

S612, after the rotating speed of the rotating shaft is accelerated to the working rotating speed, the third magnetic bearing is closed.

And S613, when the Tesla turbine is stopped, starting the third magnetic bearing.

S614, after the rotating speed of the rotating shaft is reduced to zero, the third magnetic bearing is closed.

In the above process, after the third magnetic bearing is opened, the rotating shaft is supported and reaches a preset position under the action of the third magnetic bearing, and a third gap is formed between the second foil bearing and the rotating shaft.

As the shaft rotates, the shaft starts to rotate while being lubricated by the air flow in the third gap to prevent wear. The specific process for opening the third magnetic bearing is as follows: and inputting a current signal with a preset value into the third coil, and lifting the rotating shaft under the action of the third magnetic bearing to reach a preset position.

With the rotating speed of the rotating shaft becoming larger and larger, when the rotating speed of the rotating shaft reaches the working rotating speed, the air film pressure generated by the air dynamic pressure bearing (the third gap between the second foil bearing and the rotating shaft, namely the air dynamic pressure bearing forming the radial bearing) of the radial bearing can stabilize the rotating shaft, and then the third magnetic bearing can be closed.

The rotating shaft is decelerated when the tesla turbine is stopped, and the third magnetic bearing is started when the tesla turbine is stopped until the rotating shaft is completely stopped in order to keep the rotating shaft stable in the whole process of stopping the tesla turbine.

The embodiment of the invention also provides a control method of the foil type air-magnetic hybrid radial bearing, which comprises the following steps:

s621, starting the third magnetic bearing, and controlling the rotating shaft to move in the radial direction of the rotating shaft under the action of the magnetic force of the plurality of fifth magnetic components so as to enable the rotating shaft to move to a preset radial position.

S622, after the rotating speed of the rotating shaft is accelerated to a first preset value, the third magnetic bearing is closed.

S623, when the rotating speed of the rotating shaft is accelerated to the first-order critical speed or the second-order critical speed, starting the third magnetic bearing.

Specifically, when the gas flow rate at the third gap between the rotating shaft and the second foil bearing (further, the fourth foil) reaches the first-order critical speed or the second-order critical speed, the third magnetic bearing is started until the rotating shaft is restored to the balanced radial position.

Optionally, when the rotation speed of the rotating shaft accelerates to the first-order critical speed or the second-order critical speed, the third magnetic bearing is started, including:

when the rotating speed of the rotating shaft is accelerated to a first-order critical speed or the second-order critical speed, the third magnetic bearing is controlled to be started at the maximum power; or,

when the rotating speed of the rotating shaft is accelerated to the first-order critical speed or the second-order critical speed, the third magnetic bearing is controlled to be opened in a stroboscopic mode according to a preset frequency.

S624, after the tesla turbine steadily passes the first-order critical speed or the second-order critical speed, the third magnetic bearing is closed.

And S625, starting a third magnetic bearing when the rotating speed of the rotating shaft is reduced to the first-order critical speed or the second-order critical speed in the stop process of the Tesla turbine.

Specifically, when the gas flow rate at the third gap between the rotating shaft and the second foil bearing (further, the fourth foil) is reduced to the first-order critical speed or the second-order critical speed, the third magnetic bearing is started until the rotating shaft is restored to the balanced radial position.

Optionally, when the rotation speed of the rotating shaft is reduced to a first-order critical speed or the second-order critical speed, starting the third magnetic bearing, including:

When the rotating speed of the rotating shaft is reduced to a first-order critical speed or the second-order critical speed, the third magnetic bearing is controlled to be started at the maximum power; or,

when the rotating speed of the rotating shaft is reduced to the first-order critical speed or the second-order critical speed, the third magnetic bearing is controlled to be opened in a stroboscopic mode according to a preset frequency.

S626, after the tesla turbine steadily passes through the first-order critical speed or the second-order critical speed, the third magnetic bearing is closed.

And S627, when the rotating speed of the rotating shaft is reduced to a second preset value, starting the third magnetic bearing.

S628, after the rotating speed of the rotating shaft is reduced to zero, the third magnetic bearing is closed.

As the rotational speed of the rotational shaft increases, when the rotational speed of the rotational shaft reaches a first preset value, for example, 5% to 30% of the rated rotational speed, the gas film pressure generated by the gas dynamic bearing of the radial bearing (the gas dynamic bearing forming the radial bearing, which is a third gap between the second foil bearing and the rotational shaft) can stabilize the rotational shaft, and then the third magnetic bearing can be closed.

During the stop of the tesla turbine, the rotating shaft is decelerated, and when the rotating speed of the rotating shaft is reduced to a second preset value, for example, 5% to 30% of the rated rotating speed, the third magnetic bearing is started, and the third magnetic bearing is closed until the rotating shaft is completely stopped.

Optionally, the method further comprises:

when a third gap between the rotating shaft and the second foil bearing (further, a fourth foil) is changed, the third magnetic bearing is started, so that the second foil bearing corresponding to the smaller gap side moves towards the direction approaching to the rotating shaft under the action of magnetic force between the plurality of fifth magnetic components and the sixth magnetic component;

and after the rotating shaft is positioned at the balanced radial position, the third magnetic bearing is closed.

When a load is placed on the spindle, causing the spindle to gradually descend and approach the fourth foil underneath, the third sensor (here the third sensor is preferably a pressure sensor) obtains a signal of an increase in air pressure, at which time the third magnetic bearing needs to be operated in an intervening manner. The third magnetic bearing does not directly act on the rotating shaft to enable the magnetic force to suspend upwards, but pushes the fourth foil sheet below upwards (namely to a direction close to the rotating shaft) by using the magnetic force, so that the lower gap is reduced, the pressure at the lower gap is increased, the weight of the load on the rotating shaft is adapted, and the air flow pressure in all directions of the third gap is automatically redistributed. When the rotating shaft reaches a new balanced radial position, the third magnetic bearing stops working.

When external impact disturbance occurs, the rotating shaft may quickly approach the second foil bearing, and the gap between the rotating shaft and the second foil bearing may be excessively small instantaneously, so that the local gas flow velocity at the gap reduction position approaches or even reaches the sonic velocity, and shock wave is initiated to generate the air hammer self-excitation phenomenon. The generation of shock waves causes local gas flow disturbances and upsets, with a significant step drop in pressure as the fluid velocity changes between sonic to subsonic. In this case, it is necessary to have the second foil bearing actively "dodge" the spindle, thereby increasing the gap between the spindle and the second foil bearing to maintain the air flow velocity as far as possible in the subsonic region to maintain its normal fluid pressure. Specifically, the magnetic poles of the fifth magnetic members on the opposite sides where the gap is changed need to be excited with the same polarity, that is, the direction where the gap is reduced generates a suction force for sucking back the second foil bearing, and the direction where the gap is increased generates a suction force for pulling back the rotating shaft. Thus, the difference of magnetic force is generated by utilizing the difference of the acting distances of the magnetic forces on the two sides, so that the rotating shaft is pulled to restore the normal gap between the rotating shaft and the second foil bearing, and the rotating shaft is returned to a new balanced radial position.

In the process, the advantages of the third magnetic bearing that the real-time control is convenient are utilized, and the factors of the unbalanced mass of the rotating shaft or the excessive deflection of the rotating shaft caused by the whirling of the rotating shaft and the like are actively balanced, so that the rotating shaft is fixed in a certain minimum range in the radial direction. In addition, in the acceleration process of the rotating shaft, the position (namely the linear velocity supersonic speed part) where the shock wave is generated can be accurately positioned, and the third magnetic bearing generates opposite force to balance the shock wave action by controlling the current magnitude, the direction and the like of the third magnetic bearing. And after the shock wave is stable, the control strategy of the third magnetic bearing is adjusted again, and the rotating shaft is fixed in a certain minimum range in the most energy-saving mode.

firstly, the electromagnetic bearing and the gas bearing work cooperatively, so that the dynamic performance and stability of the bearing in a high-speed running state are improved, the disturbance resistance is high, and the bearing capacity of the bearing is further improved. Meanwhile, the electromagnetic bearing and the gas bearing adopt a nested structure, so that the structure is simplified, the integration level is high, the processing, the manufacturing and the operation are easy, and the comprehensive performance of the bearing is improved. When the Tesla turbine is started or stopped, the thrust disc and the stator of the bearing can rotate in the bearing clearance by using the electromagnetic bearing, so that the low-speed performance of the bearing is improved, the service life of the bearing is prolonged, and the safety and reliability of the bearing and the whole system can be improved.

Secondly, compared with the traditional aerostatic and static pressure mixed thrust bearing adopting the combination of the aerostatic pressure bearing and the aerodynamic pressure bearing, the foil type aeromagnetic mixed radial bearing provided by the embodiment of the invention has the advantage of high response speed.

Example seven

Fig. 30 to 37 are schematic structural views of a groove-type air-magnetic hybrid radial bearing according to an embodiment of the present invention.

As shown in fig. 30 to 37, the groove type air-magnetic hybrid radial bearing 6200 includes:

a fourth magnetic bearing 6201 sleeved on the rotating shaft 100, wherein a plurality of seventh magnetic components are circumferentially arranged on the fourth magnetic bearing 6201;

A third dynamic pressure generating groove 6202 is provided on a side wall of the fourth magnetic bearing 6201 facing the rotating shaft 100, or on a circumferential surface of the rotating shaft 100 facing the fourth magnetic bearing 6201;

wherein, there is a fourth gap 6203 between the fourth magnetic bearing 6201 and the rotating shaft 100, and the rotating shaft 100 is capable of moving in a radial direction of the rotating shaft 100 under the magnetic force of the seventh magnetic members.

In the embodiment of the present invention, the fourth gap 6203 and the fourth magnetic bearing 6201 are disposed in the radial bearing 6200, so that the radial bearing 6200 forms a gas-magnetic hybrid radial bearing.

When the radial bearing 6200 works, the gas bearing in the radial bearing 6200 and the fourth magnetic bearing 6201 can work cooperatively, and when the radial bearing 6200 is in a stable working state, the support is realized by the gas bearing; while the radial bearing 6200 is in an unstable operating state, the radial bearing 6200 is controlled and responded to by means of the fourth magnetic bearing 6201 in time.

In the embodiment of the present invention, when the rotation shaft 100 rotates, the flowing gas existing in the fourth gap 6203 is pressed into the third dynamic pressure generating groove 6202, thereby generating pressure to float the rotation shaft 100, so that the rotation shaft 100 is held contactlessly in the radial direction. The pressure generated by the third dynamic pressure generating groove 6202 varies with the angle, width, length, depth, number and flatness of the third dynamic pressure generating groove 6202. In addition, the amount of pressure generated by the third dynamic pressure generating groove 6202 is also related to the rotational speed of the shaft 100 and the fourth gap 6203. Parameters of the third dynamic pressure generating tank 6202 may be designed according to actual conditions. The third dynamic pressure generating groove 6202 may be formed on the fourth magnetic bearing 6201 or the rotating shaft by forging, rolling, etching, or punching, etc.

Optionally, the plurality of seventh magnetic components includes a plurality of fourth permanent magnets disposed circumferentially on the fourth magnetic bearing 6201;

alternatively, the seventh magnetic elements include a plurality of fourth electromagnets circumferentially disposed on the fourth magnetic bearing 6201, each of the plurality of fourth electromagnets including a fourth magnetic core 62011 disposed on the fourth magnetic bearing 6201 and a fourth coil 62012 wound around the fourth magnetic core 62011.

In the embodiment of the present invention, when the groove type air-magnetic hybrid radial bearing 6200 only needs the magnetic component to provide magnetic force without magnetic control, the seventh magnetic component is preferably a fourth permanent magnet; when the foil type air-magnetic hybrid thrust bearing requires both magnetic force and magnetic control, the seventh magnetic component is preferably a fourth electromagnet.

When the seventh magnetic element is a fourth electromagnet, a current is applied to the fourth coil 62012, so that the fourth magnetic core 62011 generates a magnetic force. The magnitude of the current flowing into the fourth coil 62012 is different, and the magnitude of the magnetic force generated by the fourth magnetic core 62011 is also different; the direction in which current is supplied to the fourth magnetic core 62012 is different, and the magnetic pole of the fourth magnetic core 62011 is also different.

In the preferred embodiment of the present invention, the fourth magnetic core 62011 may be formed by laminating a plurality of silicon steel sheets or silicon steel sheets, because the silicon steel sheets or silicon steel sheets have physical characteristics of high magnetic permeability, low eddy current loss, etc.

Optionally, the fourth magnetic bearing 6201 includes:

a fourth magnetic bearing seat 62013, wherein the fourth magnetic bearing seat 62013 is sleeved on the rotating shaft 100, a plurality of fourth accommodating grooves 6204 are circumferentially arranged on the fourth magnetic bearing seat 62013, a plurality of seventh magnetic components are arranged in the fourth accommodating grooves 62014, and magnetic poles of the seventh magnetic components face the rotating shaft 100;

A second bearing housing 62015 sleeved outside the fourth magnetic bearing block 62013;

a second bearing housing 62016 sleeved between the fourth magnetic bearing housing 62013 and the rotating shaft 100;

and a fifth end cap 62017 and a sixth end cap 62018 provided at both ends of the second bearing housing 62015, respectively;

wherein the second bearing housing 62016, the fifth end cap 62017 and the sixth end cap 62018 cooperate to secure the seventh plurality of magnetic elements to the fourth magnetic bearing housing 62013.

In the embodiment of the present invention, by providing the second bearing cover 62016, a gap between the fourth magnetic core 62011 and the fourth coil 62012 can be closed, so that a stable and uniform air film pressure is formed between the second bearing cover 62016 and the rotating shaft 100. In addition, the size of the fourth gap 6203 can be conveniently adjusted and controlled by providing the second bearing sleeves 62016 with different radial thicknesses.

The fourth gap 6203 between the second bearing housing 62016 and the rotating shaft 100 may have a width of 5 μm to 12 μm, preferably 8 μm to 10 μm.

In the preferred embodiment of the present invention, the fourth magnetic bearing seat 62013 may be formed by stacking a plurality of silicon steel sheets or silicon steel sheets, because the silicon steel sheets or silicon steel sheets have physical characteristics of high magnetic permeability, low eddy current loss, etc. The number of the fourth receiving grooves 62014 may be, but is not limited to, six or eight, uniformly arranged along the circumferential direction of the fourth magnetic bearing seat 62013. In this way, the magnetic force between the fourth magnetic bearing 6201 and the rotating shaft 100 can be made more uniform and stable. The plurality of seventh magnetic members may be provided on the fourth magnetic bearing block 62013 in other manners, and this is not limited thereto. The materials of the fifth end cap 62017 and the sixth end cap 62018 can both be non-magnetic materials, preferably duralumin materials. The material of the second bearing housing 62016 may be a non-magnetic material, preferably a duralumin material. The material of the second bearing housing 62015 may be a non-magnetic material, preferably a duralumin material.

Preferably, the fifth end cap 62017 and the sixth end cap 62018 are each provided with a boss having the same outer diameter as the inner diameter of the second bearing housing 62015, and the bosses of the fifth end cap 62017 and the sixth end cap 62018 are used to fix and compress silicon steel sheets or sheets constituting the fourth magnetic bearing housing 62013 from both ends.

In an embodiment of the present invention, a third dynamic pressure generating groove 6202 may be provided on the second bearing housing 62016, and the second bearing housing 62016 may be made of a stainless steel material in order to facilitate the processing of the third dynamic pressure generating groove 6202. Specifically, the third dynamic pressure generating grooves 6202 may be disposed in a middle portion of the rotating shaft 100 corresponding to the circumferential surface of the second bearing housing 62016, or may be disposed as two mutually independent third dynamic pressure generating grooves 6202 symmetrically disposed on both sides of the middle portion; the third dynamic pressure generating groove 6202 may be disposed in a middle portion of the inner sidewall of the second bearing housing 62016, or may be disposed as two independent third dynamic pressure generating grooves 6202 symmetrically disposed at two ends of the inner sidewall of the second bearing housing 62016.

Optionally, the third dynamic pressure generating grooves 6202 are arranged in a matrix, which is advantageous for more uniformly distributing the air film in the fourth gap 6203.

Optionally, the third dynamic pressure generating grooves 6202 are V-shaped grooves arranged continuously or at intervals.

In the embodiment of the present invention, by adopting the above-mentioned arrangement mode of the third dynamic pressure generating groove 6202, the rotating shaft 100 can be held in a non-contact manner in a desired manner under the condition that the rotating shaft 100 rotates in the forward direction or rotates in the reverse direction, so that the rotating shaft 100 has the advantages of high load capacity and good stability. The third dynamic pressure generating groove 6202 may be provided as a herringbone groove or other shaped groove in addition to the V-shaped groove.

Optionally, a second static pressure air inlet throttle hole 6205 is further disposed on the fourth magnetic bearing 6201, one end of the second static pressure air inlet throttle hole 6205 is communicated with the fourth gap 6203, and the other end is connected with an external air source for conveying the external air source into the fourth gap 6203.

In the embodiment of the present invention, by providing the second static pressure air inlet orifice 6205, a gas static pressure bearing may be formed, so that the groove type gas magnetic hybrid radial bearing 6200 may form a groove type gas dynamic static pressure-magnetic hybrid radial bearing. The flow diameter of the second static pressure air inlet orifice 6205 may be adjusted according to actual conditions such as air flow requirements.

Optionally, the second static pressure intake orifice 6205 is split within the fourth magnetic bearing 6201 into at least two branches that communicate into the fourth gap 6203.

In an embodiment of the present invention, the second static pressure air inlet orifice 6205 may sequentially pass through the fifth end cap 62017 or the sixth end cap 62018, the fourth magnetic bearing 6201, and the second bearing 62016 to communicate the external air source with the fourth gap 6203. Further, the second static pressure intake orifice 6205 may be split into two or more branches that communicate to the fourth gap 6203, such that the gas film pressure within the fourth gap 6203 is more uniform. Further, an annular groove may be provided on the fifth end cap 62017 or the sixth end cap 62018, and a plurality of second static pressure air intake orifices 6205 may be provided in an annular region of the fourth magnetic bearing 6201 corresponding to the annular groove, for example, one second static pressure air intake orifice 6205 may be provided in each fourth magnetic core 62011 or in each two adjacent fourth magnetic cores 62011. The flow diameter of the second static pressure air inlet orifice 6205 and the branch can be adjusted according to actual working conditions such as air flow requirements.

Optionally, the groove-type aero-magnetic hybrid radial bearing 6200 further includes a plurality of fourth sensors 6204 disposed at intervals along the circumferential direction of the fourth magnetic bearing 6201, wherein a sensor probe of each fourth sensor 6204 is disposed within the fourth gap 6203.

In the embodiment of the present invention, by providing the fourth sensor 6204, a parameter at the fourth gap 6203, for example, the gas film pressure at the fourth gap 6203, can be detected in real time. In this way, the fourth magnetic bearing 6201 can actively control the radial bearing 6200 according to the detection result of the fourth sensor 6204, and can achieve higher accuracy of control.

Optionally, in the plurality of fourth sensors 6204, each fourth sensor 6204 includes a fourth sensor cover 62041 and a fourth sensor probe 62042, a first end of the fourth sensor probe 62042 is connected to the fourth sensor cover 62041, the fourth sensor cover 62041 is fixed on the fourth magnetic bearing 6201, and a through hole for the fourth sensor probe 62042 to pass through is provided on the fourth magnetic bearing 6201; the second end of the fourth sensor probe 62042 passes through the through hole in the fourth magnetic bearing 6201 and extends to the fourth gap 6203, and the second end of the fourth sensor probe 62042 is flush with the side of the fourth magnetic bearing 6201 adjacent to the rotating shaft 100.

In the embodiment of the present invention, the fourth sensor 6204 can be more stably disposed on the fourth magnetic bearing 6201 by the structural form and the mounting manner of the fourth sensor 6204. In addition, the second end of the fourth sensor probe 62042 is flush with the side, close to the rotating shaft 100, of the fourth magnetic bearing 6201, so that on one hand, the fourth sensor probe 62042 can be prevented from being touched by the rotating shaft 100, and the fourth sensor probe 62042 can be protected; on the other hand, the air film in the fourth gap 6203 is not affected, and the air film in the fourth gap 6203 is prevented from being disturbed.

In an embodiment of the present invention, the number of fourth sensors 6204 may be the same as the number of seventh magnetic elements. The fourth sensor 6204 may be disposed between two adjacent seventh magnetic members or may be disposed through the seventh magnetic members, which is not limited in the embodiment of the present invention. Each fourth sensor 6204 is preferably disposed in the middle of the fourth magnetic bearing 6201.

Optionally, the plurality of fourth sensors 6204 is any one or a combination of the following:

a displacement sensor for detecting the position of the rotation shaft 100;

a pressure sensor for detecting the gas film pressure at the fourth gap 6203;

a speed sensor for detecting the rotation speed of the rotation shaft 100;

an acceleration sensor for detecting rotational acceleration of the rotation shaft 100.

The following describes in detail a specific control method when the groove type air-magnetic hybrid radial bearing (wherein the seventh magnetic component in the fourth magnetic bearing is an electromagnet) participates in the control process of the tesla turbine.

The embodiment of the invention provides a control method of a groove type air-magnetic hybrid radial bearing, which comprises the following steps:

s631, opening the fourth magnetic bearing, controlling the rotating shaft to move in the radial direction of the rotating shaft under the action of the magnetic force of the seventh magnetic components, and pushing the rotating shaft to a preset radial position.

S632, after the rotating speed of the rotating shaft is accelerated to the working rotating speed, the fourth magnetic bearing is closed.

And S633, when the Tesla turbine is stopped, starting the fourth magnetic bearing.

S634, after the rotating speed of the rotating shaft is reduced to zero, the fourth magnetic bearing is closed.

In the above process, after the fourth magnetic bearing is opened, the rotating shaft is supported under the action of the fourth magnetic bearing and reaches the preset radial position, and a fourth gap is formed between the fourth magnetic bearing and the rotating shaft.

With the rotation of the rotating shaft, the rotating shaft starts to rotate under the condition of being lubricated by the air flow in the fourth gap so as to prevent abrasion. The specific process of opening the fourth magnetic bearing is as follows: and inputting a current signal with a preset value into the fourth coil, and lifting the rotating shaft under the action of the fourth magnetic bearing to reach a preset radial position.

With the increasing rotation speed of the rotating shaft, when the rotation speed of the rotating shaft reaches the working rotation speed, the gas film pressure generated by the gas dynamic pressure bearing of the radial bearing (the gas dynamic pressure bearing forming the radial bearing is formed by arranging a fourth gap between the fourth magnetic bearing and the rotating shaft) can stabilize the rotating shaft, and then the fourth magnetic bearing can be closed.

When the Tesla turbine is stopped, the rotating shaft is decelerated, and in order to keep the rotating shaft stable in the whole Tesla turbine stopping process, the fourth magnetic bearing is started when the Tesla turbine is stopped, and the fourth magnetic bearing is closed until the rotating shaft is completely stopped.

The embodiment of the invention also provides a control method of the groove type air-magnetic hybrid radial bearing, which comprises the following steps:

s641, opening a fourth magnetic bearing, controlling the rotating shaft to move in the radial direction of the rotating shaft under the action of the magnetic force of the seventh magnetic components, and pushing the rotating shaft to a preset radial position.

S642, after the rotating speed of the rotating shaft is accelerated to a first preset value, the fourth magnetic bearing is closed.

S643, when the rotating speed of the rotating shaft is accelerated to the first-order critical speed or the second-order critical speed, the fourth magnetic bearing is started.

Specifically, when the gas flow rate at the fourth gap between the rotating shaft and the fourth magnetic bearing reaches the first-order critical speed or the second-order critical speed, the fourth magnetic bearing is started until the rotating shaft is restored to the balanced radial position.

Optionally, when the rotation speed of the rotating shaft accelerates to the first-order critical speed or the second-order critical speed, the fourth magnetic bearing is started, including:

when the rotating speed of the rotating shaft is accelerated to a first-order critical speed or a second-order critical speed, the fourth magnetic bearing is controlled to be started at the maximum power; or,

when the rotating speed of the rotating shaft is accelerated to the first-order critical speed or the second-order critical speed, the fourth magnetic bearing is controlled to be opened in a stroboscopic mode according to the preset frequency.

S644, after the Tesla turbine steadily passes the first-order critical speed or the second-order critical speed, the fourth magnetic bearing is closed.

And S645, in the shutdown process of the Tesla turbine, when the rotating speed of the rotating shaft is reduced to a first-order critical speed or a second-order critical speed, starting the fourth magnetic bearing.

Specifically, when the gas flow rate at the fourth gap between the rotating shaft and the fourth magnetic bearing is reduced to the first-order critical speed or the second-order critical speed, the fourth magnetic bearing is started until the rotating shaft is restored to the balanced radial position.

Optionally, when the rotation speed of the rotating shaft is reduced to a first-order critical speed or a second-order critical speed, the fourth magnetic bearing is started, including:

when the rotating speed of the rotating shaft is reduced to a first-order critical speed or a second-order critical speed, the fourth magnetic bearing is controlled to be started at the maximum power; or,

when the rotating speed of the rotating shaft is reduced to the first-order critical speed or the second-order critical speed, the fourth magnetic bearing is controlled to be opened in a stroboscopic mode according to the preset frequency.

S646, after the tesla turbine steadily passes the first-order critical speed or the second-order critical speed, the fourth magnetic bearing is closed.

S647, when the rotating speed of the rotating shaft is reduced to a second preset value, starting the fourth magnetic bearing.

S648, after the rotating speed of the rotating shaft is reduced to zero, the fourth magnetic bearing is closed.

With the increasing rotation speed of the rotating shaft, when the rotation speed of the rotating shaft reaches a first preset value, for example, 5% to 30% of the rated rotation speed, the gas film pressure generated by the gas dynamic bearing of the radial bearing (the gas dynamic bearing forming the radial bearing by arranging a fourth gap between the fourth magnetic bearing and the rotating shaft) can stabilize the rotating shaft, and then the fourth magnetic bearing can be closed.

During the stop of the tesla turbine, the rotating shaft is decelerated, and when the rotating speed of the rotating shaft is reduced to a second preset value, for example, 5% to 30% of the rated rotating speed, the fourth magnetic bearing is started, and the fourth magnetic bearing is closed until the rotating shaft is completely stopped.

Optionally, the method further comprises:

when a fourth gap between the rotating shaft and the fourth magnetic bearing is changed, the rotating shaft is moved to a direction away from the gap reducing side under the magnetic force action of the seventh magnetic components;

And after the rotating shaft is at the balanced radial position, the fourth magnetic bearing is closed.

When a load is applied to the rotating shaft, and the rotating shaft is gradually lowered and approaches the fourth magnetic bearing below, the fourth sensor (the fourth sensor herein is preferably a pressure sensor) obtains a signal of an increase in air pressure, and the fourth magnetic bearing needs to be involved in operation. The fourth magnetic bearing acts on the rotating shaft to enable the rotating shaft to suspend upwards, and when the rotating shaft reaches a new balance position, the fourth magnetic bearing stops working.

When external impact disturbance occurs, the rotating shaft may quickly approach the fourth magnetic bearing, and the gap between the rotating shaft and the fourth magnetic bearing may be excessively small instantaneously, so that the local gas flow velocity at the gap reduction position approaches or even reaches the sonic velocity, and the shock wave is induced to generate the air hammer self-excitation phenomenon. The generation of shock waves causes local gas flow disturbances and upsets, with a significant step drop in pressure as the fluid velocity changes between sonic to subsonic. In this case, it is necessary to control the seventh magnetic members of the fourth magnetic bearing to be alternately turned on at a preset frequency to provide a damping effect on the disturbance, thereby effectively suppressing the external disturbance. After the shaft returns to the new equilibrium radial position, the fourth magnetic bearing stops.

In the embodiment of the present invention, when the electromagnetic bearing (the seventh magnetic component in the fourth magnetic bearing is an electromagnet, that is, the electromagnetic bearing) and the hydrostatic gas bearing (the second hydrostatic air intake orifice provided in the fourth magnetic bearing is the hydrostatic gas bearing) are simultaneously provided, the electromagnetic bearing and the hydrostatic gas bearing may be mutually spare, and when one of them fails, or the opening condition cannot be satisfied, the other may serve as a spare bearing. For example, in case of detecting a failure of the electromagnetic bearing, an external air source is controlled to be turned on to perform a corresponding action instead of the electromagnetic bearing, thereby improving the safety and reliability of the bearing.

In the embodiment of the present invention, in the case where the electromagnetic bearing and the aerostatic bearing are provided at the same time, the step of "opening the aerostatic bearing in the radial bearing to move the rotating shaft to the preset radial position" may include the following implementation manner:

starting the fourth magnetic bearing and/or starting an external air source, and conveying air to the fourth gap through the second static pressure air inlet orifice;

and controlling the rotating shaft to move in the radial direction of the rotating shaft under the action of magnetic force of the seventh magnetic components and/or the pushing action of the gas so as to enable the rotating shaft to move to a preset radial position.

In the process, the advantages of the fourth magnetic bearing that the real-time control is convenient are utilized, and the factors of the unbalanced mass of the rotating shaft or the excessive deflection of the rotating shaft caused by the whirling of the rotating shaft and the like are actively balanced, so that the rotating shaft is fixed in a certain minimum range in the radial direction. In addition, in the acceleration process of the rotating shaft, the position (namely the linear velocity supersonic speed part) where the shock wave is generated can be accurately positioned, and the shock wave effect is balanced by controlling the current magnitude, the direction and the like of the fourth magnetic bearing, so that the fourth magnetic bearing generates opposite force. And after the shock wave is stable, the control strategy of the fourth magnetic bearing is adjusted again, and the rotating shaft is fixed in a certain minimum range in the most energy-saving mode.

firstly, the electromagnetic bearing and the gas bearing work cooperatively, so that the dynamic performance and stability of the bearing in a high-speed running state are improved, the disturbance resistance is high, and the bearing capacity of the bearing is further improved. Meanwhile, the electromagnetic bearing and the gas bearing adopt a nested structure, so that the structure is simplified, the integration level is high, the processing, the manufacturing and the operation are easy, and the comprehensive performance of the bearing is improved. When the Tesla turbine is started or stopped, the thrust disc and the stator of the bearing can rotate in the first gap by using the electromagnetic bearing, so that the low-speed performance of the bearing is improved, the service life of the bearing is prolonged, and the safety and reliability of the bearing and the whole system can be improved.

Secondly, compared with the traditional aerostatic and static pressure mixed thrust bearing adopting the combination of the aerostatic bearing and the aerodynamic bearing, the groove type aeromagnetic mixed radial bearing provided by the embodiment of the invention has the advantage of high response speed.

The foregoing is merely illustrative embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think about variations or substitutions within the technical scope of the present invention, and the invention should be covered. Therefore, the protection scope of the invention is subject to the protection scope of the claims.

Claims

1. A power generation system, comprising:

waste heat boilers, tesla turbines and motors;

the tesla turbine is provided with a medium inlet and a medium outlet;

the at least one heat exchanger comprises a first heat exchanger, a heat medium inlet of the first heat exchanger is communicated with an exhaust pipe of the gas turbine, and a heat medium outlet of the first heat exchanger is positioned outside the shell;

the tesla turbine comprises: a rotating shaft;

The thrust bearing and the at least two radial bearings are non-contact bearings;

the thrust bearing is a gas-magnetic hybrid thrust bearing;

at least one radial bearing in the at least two radial bearings is a gas-magnetic hybrid radial bearing or a gas dynamic-static pressure hybrid radial bearing;

the air-magnetic hybrid thrust bearing is a foil type air-magnetic hybrid thrust bearing, and the foil type air-magnetic hybrid thrust bearing comprises: the first thrust disc is fixedly connected to the rotating shaft;

the first foil bearing is arranged between the first magnetic bearing and the first thrust disc, a first gap is formed between the first foil bearing and the first thrust disc, and the first foil bearing can move in the axial direction of the rotating shaft under the action of magnetic force between the first magnetic component and the second magnetic component;

The at least one heat exchanger further comprises a second heat exchanger, and a heating medium inlet of the second heat exchanger is communicated with the condensation pipeline;

high-temperature gas exhausted by an exhaust pipe of the gas turbine enters the first heat exchanger through a heat medium inlet of the first heat exchanger, exchanges heat with a liquid medium in a shell of the waste heat boiler, and after heat exchange, the high-temperature gas is exhausted out of the shell of the waste heat boiler through a heat medium outlet of the first heat exchanger.

2. The power generation system of claim 1, wherein the power generation system comprises a power generator,

the liquid medium is water.

3. The power generation system of claim 1, wherein the power generation system comprises a power generator,

the first heat exchanger and the second heat exchanger are both tubular heat exchangers, and the tubular heat exchangers comprise: the heat exchange device comprises a first pipe body, a second pipe body and a heat exchange element, wherein the outer diameter of the first pipe body is smaller than the inner diameter of the second pipe body, and the second pipe body is sleeved outside the first pipe body;

4. The power generation system of claim 3, wherein,

and gaps are arranged between any two adjacent heat exchange elements in the axial direction and the radial direction of the first pipe body.

5. A power generation system according to claim 3, wherein the heat exchange element is shaped in a regular or irregular configuration.

6. The power generation system according to claim 5, wherein when the heat exchange element is in a regular structure, the heat exchange element is a corrugated plate, a fin plate or a water drop shape with the heat exchange element in a flow direction;

7. The power generation system of claim 1, wherein the power generation system comprises a power generator,

the thrust bearing is arranged in the shell;

8. The power generation system of claim 1, wherein the aero-magnetic hybrid radial bearing is a foil aero-magnetic hybrid radial bearing comprising: the third magnetic bearing is sleeved on the rotating shaft, and a plurality of fifth magnetic components are arranged on the third magnetic bearing along the circumferential direction;

and a third gap is arranged between the second foil bearing and the rotating shaft, and the second foil bearing can move in the radial direction of the rotating shaft under the action of the magnetic force of the fifth magnetic components and the sixth magnetic components.

9. The power generation system of claim 1, wherein the hybrid gas-magnetic radial bearing is a groove hybrid gas-magnetic radial bearing comprising: the fourth magnetic bearing is sleeved on the rotating shaft, and a plurality of seventh magnetic components are arranged on the fourth magnetic bearing along the circumferential direction;

A third dynamic pressure generating groove is formed in the circumferential surface of the fourth magnetic bearing facing to the side wall of the rotating shaft or the rotating shaft facing to the fourth magnetic bearing;

10. The power generation system of claim 9, wherein the fourth magnetic bearing is further provided with a static pressure air inlet orifice, one end of the static pressure air inlet orifice is communicated with the fourth gap, and the other end of the static pressure air inlet orifice is connected with an external air source for conveying the external air source into the fourth gap.

11. A control method of a power generation system for use in the power generation system according to any one of claims 1 to 10, comprising: the liquid medium in the shell of the waste heat boiler is heated to become steam, the steam enters a Tesla turbine through a steam pipeline of the shell, and the steam drives the Tesla turbine to work so as to drive the motor to generate electricity;

The steam discharged by the Tesla turbine after the temperature reduction exchanges heat with the liquid medium in the shell, so that the temperature of the liquid medium in the shell is increased.

12. The method of claim 11, wherein the reduced temperature steam exiting the tesla turbine exchanges heat with the liquid medium within the housing to raise the temperature of the liquid medium within the housing, comprising: and the steam with the reduced temperature discharged by the Tesla turbine enters the second heat exchanger through a heat medium inlet of the second heat exchanger to exchange heat with the liquid medium in the shell, so that the temperature of the liquid medium in the shell is increased.