Detailed Description
the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1, an embodiment of the present invention provides a power system, including:
A gas turbine generator set 1, an electric motor 2, a propulsion system 3 and a control system (not shown in the figures).
the gas turbine generator set 1 comprises a gas turbine engine 11 and a first motor 12 which are coaxially connected, the gas turbine engine 11 comprises a compressor and a first turbine, and the compressor, the first turbine and the first motor 12 are connected through a first rotating shaft. The first motor 12 is electrically connected to the motor 2, the motor 2 is connected to the propulsion system 3, and the motor 2 is used for driving the propulsion system 3 to move.
The control system is electrically connected to the first electric machine 12, and after the gas turbine engine 11 is started and stabilized, the control system is used to control the generated power of the first electric machine 12, and the shaft power generated by the gas turbine engine 11 is used to provide thrust and generate electricity in a predetermined ratio by the control of the control system.
For a traditional power system, a propulsion system is mechanically connected with an engine coaxially, and the engine directly drives the propulsion system to work. Thus, if the engine stops rotating, the propulsion system will also stop rotating, causing the power system to malfunction.
Whereas in the power system of the present embodiment, propulsion system 3 is electrically driven by electric motor 2, the connection between propulsion system 3 and gas turbine engine 11 is no longer a mechanical connection. In this way, a failure of gas turbine engine 11 does not have the aforementioned effects on propulsion system 3.
additionally, with conventional power systems, the engine is configured to operate under different operating conditions. Since the engine is mechanically connected to the propulsion system, the engine rotates at the same speed as the propulsion system. Therefore, the rotation speed of the engine needs to be changed within a certain range for different working conditions, so that the power output by the engine is different. This increases the design difficulty of the engine, e.g. the geometry of the rotor, the geometry of the stator, etc.
In the power system of the embodiment of the invention, the first motor 12 is arranged, so that the thrust output by the gas turbine engine 11 can be adjusted by adjusting the power generated by the first motor 12, thereby meeting the requirements of different working conditions. In this way, the gas turbine engine 11 can be ensured to operate in a stable operating state all the time, which not only reduces the loss to the gas turbine engine 11, but also improves the overall efficiency of the power system.
in the embodiment of the present invention, the specific embodiment of electrically connecting the first electric machine 12 and the electric motor 2 is not limited. If the first motor 12 is an ac motor and the motor 2 is an ac motor, the first motor 12 may be directly electrically connected to the motor 2 through a cable; alternatively, the first electric machine 12 is electrically connected to the electric motor 2 through a transformer. If the first motor 12 is an ac motor and the electric motor 2 is a dc motor, a rectifier may be disposed between the first motor 12 and the electric motor 2, and the first motor 12 is electrically connected to the electric motor 2 through the rectifier; alternatively, the electric energy of the first motor 12 is first input to an energy storage device such as a battery, and the electric energy is supplied to the motor 2 through the energy storage device.
The power system of the embodiment of the invention can be applied to, but is not limited to, aircrafts and ships, and for convenience of understanding and description, the embodiment of the invention is specifically explained by focusing on the application of the power system to the aircrafts.
alternatively, as shown in fig. 1, the propulsion system 3 includes a propeller 32 and a torque conversion mechanism 31, the torque conversion mechanism 31 is connected to the propeller 32, and the torque conversion mechanism 31 is flexibly connected to the motor 2.
Wherein, the electric motor 2 drives the propeller 32 to rotate through the torque conversion mechanism 31, thereby providing flight thrust for the aircraft. Preferably, the torque conversion mechanism 31 is provided with a controller by which the output torque of the torque conversion mechanism 31 can be controlled, thereby controlling the rotation speed of the propeller 32. The controller may be a controller separate from the control system or may be a controller integrated in the control system.
Optionally, as shown in fig. 1, the power system further includes an energy storage system 4, and the energy storage system 4 is electrically connected to the first motor 12; the control system is also electrically connected to the electric motor 2 and is also configured to control the output power of the electric motor 2 to regulate the input of electric energy from the first electric machine 12 to the electric motor 2 and/or the energy storage system 4.
The energy storage system 4 may be a superconducting energy storage system, a lithium battery energy storage system, or a flywheel energy storage system, which is not limited in the embodiment of the present invention.
when the gas turbine generator set 1 fails, the electric energy stored in the energy storage system 4 can provide enough emergency electricity for the propulsion system 3, so that the safe operation of the aircraft during the failure processing or the emergency forced landing of the aircraft is ensured.
Further, the power system further includes a converter 5, and the first electric machine 12 is electrically connected to the electric motor 2 and the energy storage system 4 through the converter 5.
Further, the first electric machine 12 is an integrated electric machine, the ac-dc converter 5 specifically includes an inverter 51 and a rectifier 52, and the first electric machine 12 is electrically connected to the energy storage system 4 through the inverter 51 and the rectifier 52.
The first electric machine 12 is a starting-integration type electric machine, and the first electric machine 12 can be used as a generator or a motor.
the energy storage system 4 stores a predetermined amount of electricity in advance. During the start-up phase of the gas turbine generator set 1, the electric energy of the energy storage system 4 supplies electric energy to the first electric machine 12 through the inverter 51, and the first electric machine 12 is used as a motor to drive the gas turbine engine 11 to rotate. After the gas turbine engine 11 is started and stabilized, the first electric machine 12 can also be used as a generator to generate electricity under the driving of the gas turbine engine 11. The electrical energy generated by the first electrical machine 12 is stored in the energy storage system 4 via the rectifier 52 or is supplied to the electric motor 2.
further, the energy storage system 4 includes a conventional energy storage device 41 and an emergency energy storage device 42.
The conventional energy storage device 41 may include an electricity storage device and a control unit, and the control unit is configured to control charging and discharging of the electricity storage device and pre-warning of the amount of electricity stored in the electricity storage device. Conventional energy storage device 41 may be used to replace an Auxiliary Power Unit (APU) of an aircraft in the prior art.
when the aircraft is on the ground, the conventional energy storage device 41 can provide electric energy to ensure illumination and air conditioning in the cabin. The gas turbine generator set 1 can be started up before the aircraft takes off, by being powered by a conventional energy storage device 41, so that ground electricity, gas sources, etc. need not be relied upon. When the aircraft takes off, the power output by the gas turbine engine 11 is used for ground acceleration and climbing, so as to ensure the take-off performance of the aircraft. After the aircraft has fallen, the conventional energy storage device 41 can still supply power for lighting and air conditioning, so that the gas turbine generator set 1 can be turned off in advance, not only can the fuel be saved, but also the airport noise can be reduced.
The emergency energy storage device 42 also comprises an electrical storage device and a control unit, and the emergency energy storage device 42 can have a larger capacity and can store more electrical energy than the conventional energy storage device 41. In the event of a failure of the gas turbine power plant 1, the electrical energy provided by the emergency energy storage device 42 can be used for safe operation of the aircraft during the handling of the failure, or for emergency forced landing of the aircraft, etc.
The control unit in the conventional energy storage device 41 or the emergency energy storage device 42 may be a control unit separate from the control system, or may be a control unit integrated in the control system.
In this way, the energy generated by the gas turbine generator set 1 can be used for both the power of the aircraft flight and the excess shaft work generated by it for generating electricity. The electric energy generated by the gas turbine generator set 1 can be used to drive the propulsion system 3 and thus further the aircraft, and the surplus electric energy can also be stored in the energy storage system 4. The electrical energy stored by the energy storage system 4 may be used both for auxiliary power supply of the aircraft and for providing main power to the aircraft in case of an anomaly of the gas turbine engine 11.
The proportion of shaft power generated by the gas turbine engine 11 divided between thrust and power generation is determined by the control system according to the specific flight conditions of the aircraft.
When the aircraft is cruising at low altitude, the power density provided by the gas turbine engine 11 required by the aircraft is relatively low, the control system can control the first motor 12 to improve the power generation power, the electric energy generated by the first motor 12 is increased, the thrust output by the gas turbine engine 11 is small, and the gas turbine engine 11 is close to a complete power generation state. The electric energy generated by the first electric machine 12 can drive the propeller 32 to rotate through the electric motor 2, so as to provide the aircraft with thrust required by flight, and the surplus electric energy can be stored in the energy storage system 4.
when the aircraft flies at high altitude, the flying speed needs to be increased, and the energy generated by the gas turbine generator set 1 is all used for the flying power of the aircraft through the control of the control system. At this time, the aircraft can fly at the highest speed, for example, in a battle state, when the aircraft needs to rapidly leave a battle area, only the control command of the control system is changed. The change of the flight working condition can be realized, and the operation is simple and convenient.
in an embodiment of the present invention, the impeller of the first turbine is preferably made of a lightweight material in order to make the gas turbine engine 11 lighter in weight. For example, the impeller of the first turbine is made of a ceramic material, a ceramic fiber composite material, or the like.
In the embodiment of the invention, the gas turbine engine 11 can be a turbojet engine, the bypass ratio of the turbojet engine is zero, the engine has the advantages of simple structure, light weight, high thrust, high propulsion efficiency, good high-speed flight performance and strong acceleration capability, and can be used for fighters or military helicopters and the like.
The gas turbine engine 11 may also be a turbofan engine, the bypass ratio of which is not zero, the engine has high fuel efficiency, low noise and long flight range, and can be used for passenger aircraft.
The gas turbine engine 11 may also be a variable cycle engine, and the bypass ratio may be varied by varying cycle parameters of the variable cycle engine. When the aircraft climbs, accelerates and flies at supersonic speed, the bypass ratio of the engine can be reduced, and the engine works in a state close to a turbojet engine to increase the thrust of the engine; when the aircraft takes off and flies at subsonic speed, the bypass ratio of the engine can be increased, and the engine works in a state close to a turbofan engine so as to reduce the fuel consumption rate and the noise of the engine.
optionally, as shown in fig. 1, the power system further includes a waste heat power generation system 6, the waste heat power generation system 6 is connected to an exhaust end of the gas turbine engine 11, the waste heat power generation system 6 can convert heat in exhaust gas of the gas turbine engine 11 into electric energy, the waste heat power generation system 6 is electrically connected to the motor 2 and/or the energy storage system 4, and the electric energy generated by the waste heat power generation system 6 can be input to the motor 2 or the energy storage system 4.
In this way, the waste heat power generation system 6 replaces a regenerator in the engine of a conventional aircraft, can use the waste heat in the exhaust gas discharged from the gas turbine engine 11 for supplementary power generation, and can store or effectively utilize the electric energy. Therefore, the power system of the embodiment of the invention has higher efficiency compared with the traditional power system.
Further, the cogeneration system 6 may be a supercritical carbon dioxide cycle system or an organic rankine cycle system. Because the supercritical carbon dioxide circulating system or the organic Rankine circulating system has high waste heat utilization rate, the heat efficiency of the whole power system is improved. The efficiency of the gas turbine engine using the common heat regenerator can reach about 25% -29%, and the heat efficiency of the gas turbine engine using the supercritical carbon dioxide circulating system or the organic Rankine circulating system can reach 38.4% or even higher.
Specifically, in the embodiment of the present invention, the waste heat power generation system 6 is configured as an organic rankine cycle system, which may also be referred to as an ORC system for short.
As shown in fig. 2, the ORC system 61 includes an evaporator 611, a second turbine 612, a condenser 613, a booster pump 614, and a second motor 615, the evaporator 611, the second turbine 612, the condenser 613, and the booster pump 614 are sequentially connected in a circulating manner through a fluid pipe 616, and the fluid pipe 616 is filled with an organic working medium.
Wherein the evaporator 611 is connected with an exhaust end of the gas turbine engine 11; the second turbine 612 is connected to the second electric machine 615 through a second rotating shaft, and the second electric machine 615 is electrically connected to the electric motor 2 and/or the energy storage system 4.
further, the evaporator 611 may be disposed in an exhaust pipe of the gas turbine engine 11.
In this way, the exhaust gas of the gas turbine engine 11 is directly introduced into one side of the evaporator 611 and discharged from the other side of the evaporator 611, i.e., the heat exchange between the exhaust gas of the gas turbine engine 11 and the organic working medium is completed in the evaporator 611.
In the working state, the organic working medium in the fluid conduit 616 absorbs the heat in the exhaust gas of the gas turbine engine 11 and is heated in the evaporator 611 in an isobaric manner to be high-pressure steam, and the high-pressure steam enters the second turbine 612 to perform isentropic expansion to do work, so as to push the second turbine 612 to rotate. The second turbine 612 further drives the coaxially connected second motor 615 to rotate and generate power, the high-pressure steam of the second turbine 612 does work and then becomes low-pressure steam, the low-pressure steam releases heat to the environment in the condenser 613 and then becomes liquid, and the liquid is isentropically pressurized by the booster pump 614 and then sent to the evaporator 611 to circulate. The electrical energy generated by the second electrical machine 615 may be used to provide electrical energy to the electric motor 2 or stored in the energy storage system 4.
From thermodynamic analysis, it can be seen that the higher the temperature of the waste heat, i.e., the inlet temperature of the second turbine 612, the higher the thermal efficiency of the orc. Thus, in embodiments of the present invention, the gas turbine engine 11 may be provided without a recuperator. The exhaust gas temperature of the gas turbine engine 11 without the regenerator is higher, approximately 600 to 800 degrees celsius, than that of the conventional engine with the regenerator. The high-temperature exhaust enters the ORC system and does work, so that the waste heat recovery efficiency of the ORC system is higher.
Further, the second motor 615 is a starter-integrated motor, and the second motor 615 can be used as a generator or a motor.
In the above embodiment, the second turbine 612 of the ORC system 61 is separate from the gas turbine engine 11 and is provided with a separate second electric machine 615. The arrangement of the embodiment of the present invention is not limited thereto. The second turbine 612 may also be arranged on the shaft of the gas turbine engine 11, i.e. the first turbine is arranged coaxially with the second turbine 612. In this way, the ORC system 61 can share the first electric machine 12 with the gas turbine engine 11 to generate electricity, and the second electric machine 615 can be eliminated. The arrangement mode enables the structure of the power system to be more compact and the cost to be relatively low.
further, the organic working medium may be: organic silicon compounds, halogenated hydrocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, alkanes, benzene, xylene and other low-boiling organic working media. Specifically, which organic working medium is used may be selected according to the exhaust gas temperature of the gas turbine engine 11.
optionally, as shown in fig. 3, the power system further includes a heat exchanger 7, and the evaporator 611 is connected to the exhaust end of the gas turbine engine 11 through the heat exchanger 7.
In the organic rankine cycle process, a heat exchanger 7 may be disposed in an exhaust pipe of the gas turbine engine 11, and the organic working medium absorbs the waste heat in the exhaust gas of the gas turbine engine 11 through the heat exchanger 7 and then enters the evaporator 611 to complete the cycle.
In the case where the heat exchanger 7 is provided, the heat exchange temperature can be adjusted by changing the flow rate of the hot gas (i.e., the gas turbine engine 11 exhaust gas) entering the heat exchanger 7. Because different organic working media have different thermodynamic properties, the heat exchanger 7 can improve the heat exchange efficiency and provide different heat exchange temperatures according to the thermodynamic properties of the different organic working media, so that the organic Rankine cycle system can be suitable for more organic working media.
In the embodiment of the invention, the heat exchanger 7 can be a tube-fin heat exchanger, a plate-fin heat exchanger or a plate heat exchanger. In order to improve the heat exchange efficiency of the heat exchanger 7, the heat exchanger 7 can also adopt a tubular heat exchanger. The specific structure of the tubular heat exchanger can be referred to the relevant description in the patent application document with the application number of CN201711012579.3, and can achieve the same beneficial effects, and in order to avoid repetition, the embodiment of the present invention is not described in detail.
Further, as shown in fig. 2 or fig. 3, the power system further includes a cooling system 8, and the cooling system 8 is connected to the condenser 613.
Since the low-pressure steam after passing through the second turbine 612 still has a relatively high temperature, the low-pressure steam can be cooled more quickly by the cooling system 8 to the saturation temperature for the condensation of the organic working medium. In the embodiment of the present invention, the cooling system 8 may adopt an air cooling system, a water cooling system, a freon cooling system, and the like, which is not limited in the embodiment of the present invention.
Optionally, the first rotating shaft, the first electric machine 12, the compressor and the first turbine of the gas turbine generator set 1 form a rotor system of the gas turbine generator set 1. And a radial bearing and a thrust bearing are also arranged in the rotor system of the gas turbine generator set 1, and the radial bearing and the thrust bearing are preferably non-contact bearings.
Accordingly, a radial bearing and a thrust bearing, preferably non-contact bearings, may also be provided in ORC system 61.
By adopting the non-contact bearing, the power system of the embodiment of the invention is simple and light, can reach high rotating speed, and can further improve the efficiency of the power system.
As shown in fig. 4, an embodiment of the present invention provides a control method of a power system, including the steps of:
S11: when the aircraft is in a starting stage, the gas turbine engine is started, the gas turbine engine drives the aircraft to start, and redundant shaft work of the gas turbine engine drives the first motor to generate power.
S12: and when the aircraft is in a crawling phase, controlling the gas turbine engine to drive the first motor to idle.
in this step, the shaft power of the gas turbine engine is almost entirely used for the flight of the aircraft until the aircraft completes the creep phase.
S13: and when the aircraft is in a low-altitude cruising stage, controlling the first motor to increase the generated power, and controlling the first motor to input electric energy to the motor so that the motor drives the propulsion system to move.
In this step, the electric power generated by the first electric machine is increased, the thrust output by the gas turbine engine is reduced, and the gas turbine engine approaches a full power generation state.
S14: and when the aircraft is in a high-altitude flight stage, controlling the gas turbine engine to drive the first motor to idle.
In this step, the shaft power of the gas turbine engine is almost entirely used for the flight power of the aircraft until the aircraft completes the high-altitude flight phase.
s15: shutting down the gas turbine engine when the aircraft is shut down.
the execution order and the execution frequency of S11 to S15 are not limited. For example, after the execution of S11, S12, S13 may be executed, S14 may be executed, or S15 may be executed. Between S11 and S15, S12 (or S13, or S14) may be performed once, and S12 (or S13, or S14) may be performed multiple times.
In the embodiment of the invention, the thrust output by the gas turbine engine is adjusted by adjusting the power generation power of the motor so as to meet the requirements of different working conditions. In this way, the gas turbine engine can always operate in a stable operating state without changing the shaft power of the gas turbine engine in different operating conditions. Therefore, the embodiment of the invention can reduce the loss of the gas turbine engine and simultaneously improve the overall efficiency of the power system.
Optionally, the step of starting the gas turbine engine, the gas turbine engine driving the aircraft to start, and the excess shaft power of the gas turbine engine driving the first electric machine to generate electricity includes:
controlling an energy storage system to supply power to the first electric machine through an inverter, wherein the first electric machine is used as a motor to drive the gas turbine engine to start;
Controlling the energy storage system to stop supplying power to the first electric machine after the gas turbine engine operates stably;
the gas turbine engine drives the aircraft to start, and redundant shaft work of the gas turbine engine drives the first motor to generate electricity;
and controlling the electric energy generated by the first motor to be input into the motor through the AC-DC converter and/or to be input into the energy storage system through the AC-DC converter for storage.
Optionally, the method further includes:
when the gas turbine engine fails, starting an emergency energy storage device to provide flight power for the aircraft;
And when the aircraft completes fault treatment or emergency forced landing, closing the emergency energy storage device.
Optionally, the method further includes:
Converting heat in the gas turbine engine exhaust to electrical energy and controlling the electrical energy input to the electric motor and/or to the energy storage system for storage.
Optionally, the step of converting heat in the gas turbine engine exhaust into electrical energy and controlling the electrical energy input to the electric motor and/or to the energy storage system for storage comprises:
The organic working medium in the fluid pipeline absorbs the heat in the exhaust gas of the gas turbine engine and is isobarically heated in the evaporator to be high-pressure steam;
The high-pressure steam enters a second turbine for isentropic expansion to do work, and the second turbine is pushed to rotate;
The second turbine drives a second electric machine to rotate to generate electricity, and the electric energy generated by the second electric machine is input into the electric motor and/or is input into the energy storage system to be stored;
the high-pressure steam of the second turbine is changed into low-pressure steam after acting, the low-pressure steam is changed into liquid after releasing heat in the condenser, and then is sent into the evaporator for circulation after being subjected to isentropic pressurization by the booster pump.
As a preferred embodiment, the control method of the power system includes the steps of:
Gas turbine engine start-up phase: the control system controls the energy storage system to supply power to the motors through the inverter, the first motor serves as a motor to drive the gas turbine engine to start, after the gas turbine engine is stabilized, the gas turbine engine provides power for the aircraft to drive the aircraft to fly, meanwhile, surplus shaft work of the gas turbine engine is used for driving the first motor to generate power, and electric energy generated by the first motor is used for driving the propulsion system or is stored in the energy storage system.
The crawling stage of the aircraft: the control system controls the gas turbine engine to drive the first motor to idle, so that the shaft power of the gas turbine engine is almost completely used for the flight of the aircraft until the aircraft finishes a crawling phase.
And (3) during a low-altitude cruising stage: the control system controls the first motor to improve the power generation power, the electric energy generated by the first motor is increased, the thrust output by the gas turbine engine is reduced, the gas turbine engine is close to a complete power generation state, the electric energy generated by the first motor drives the propeller to rotate through the motor, the thrust required by flight is provided for the aircraft, and redundant electric energy is stored in the energy storage system.
And (3) high-altitude flight stage: the control system controls the gas turbine engine to drive the first motor to idle, and the energy generated by the gas turbine generator set is all used for the flight power of the aircraft, so that the aircraft flies at the highest speed.
upon failure of the gas turbine engine: the control system starts the emergency energy storage device to provide flight power for the aircraft, and after the aircraft completes fault treatment or emergency forced landing, the control system closes the emergency energy storage device.
the waste heat power generation system utilizes exhaust waste heat to supplement power generation: in the operation process of the first four steps, the waste heat power generation system absorbs waste heat in exhaust gas of the gas turbine engine, and converts the exhaust waste heat into electric energy to be stored in the energy storage system or directly used for providing electric energy for the driving motor.
in the embodiment of the present invention, the following may be referred to for the specific structural form of the rotor system of the gas turbine generator set 1 and the control method of "starting the gas turbine engine" in the control process of the power system.
In the embodiment of the present invention, the rotor system of the gas turbine generator set 1 may adopt a horizontal rotor system: the shaft body of the first rotating shaft is of an integrated structure, and the first rotating shaft is horizontally arranged; the first rotating shaft is further provided with a thrust bearing and at least two radial bearings, and the thrust bearing and the at least two radial bearings are non-contact bearings. The thrust bearing is arranged at a preset position on one side of the first turbine close to the compressor, and the preset position is a position which enables the gravity center of the rotor system to be located between two radial bearings which are farthest away from each other in the at least two radial bearings.
In an embodiment of the present invention, the thrust bearing is a bearing for restricting movement of the rotating shaft in the axial direction, and the radial bearing is a bearing for restricting movement of the rotating shaft in the radial direction.
with the increase of the rotating speed of the rotor, the common contact type bearing can not meet the requirement of the high-rotating-speed rotor. Therefore, in the embodiment of the invention, in order to meet the development requirement of high-speed rotation of the rotor, the thrust bearing and the radial bearing can adopt non-contact bearings.
In the embodiment of the invention, the shaft body of the rotating shaft is an integral structure, which can be understood as that the shaft body of the rotating shaft is an integral shaft, or the shaft body of the rotating shaft is formed by rigidly connecting a plurality of shaft sections. Because the axis body of pivot is structure as an organic whole, the intensity of the axis body everywhere in the pivot has the uniformity, and this makes thrust bearing be unrestricted in the epaxial position that sets up of pivot.
Further, in order to keep the entire rotor system stable in structure even when rotating at a high speed, the center of gravity of the entire rotor system should be located between the two radial bearings which are farthest away from each other among the at least two radial bearings. Therefore, the whole rotor system forms a spindle structure, and is different from the traditional cantilever type structure, and the stability of the whole rotor system is improved by the embodiment of the invention. Since the setting position of the thrust bearing on the rotating shaft is not limited, in the embodiment of the present invention, the setting position of the thrust bearing may be flexibly adjusted according to the parameters such as the setting number of the radial bearings of the at least two radial bearings, the setting position of each radial bearing, and the mass of each component in the entire rotor system (including the mass of the thrust bearing itself), so that the center of gravity of the entire rotor system is located between the two radial bearings which are farthest away from each other, and preferably, the center of gravity of the entire rotor system is located on the compressor.
in the embodiment of the present invention, the rotating shaft is horizontally disposed, and therefore, it can be understood that the rotor system of the embodiment of the present invention is a horizontal rotor system, which may be applied to a horizontal unit that needs to use the horizontal rotor system, such as a horizontal gas turbine generator set that will be specifically described below.
In order to better understand the overall technical scheme of the rotor system according to the embodiment of the present invention, the following describes the rotor system according to the embodiment of the present invention with reference to the accompanying drawings.
as shown in fig. 5 to 7, the rotor system includes:
The rotating shaft 100, the shaft body of the rotating shaft 100 is an integral structure, and the rotating shaft 100 is horizontally arranged;
a motor 200, a compressor 300 and a turbine 400 sequentially arranged on the rotating shaft 100;
And a thrust bearing 500, a first radial bearing 600 and a second radial bearing 700 which are arranged on the rotating shaft 100, wherein the first radial bearing 600 is arranged on the side of the motor 200 far away from the compressor 300, and the second radial bearing 700 is arranged between the compressor 300 and the turbine 400.
The thrust bearing 500 is disposed between the first radial bearing 600 and the motor 200, as shown in fig. 5; alternatively, the thrust bearing 500 is disposed on a side of the first radial bearing 600 away from the motor 200, as shown in fig. 6; alternatively, the thrust bearing 500 is disposed between the motor 200 and the compressor 300, as shown in fig. 7.
in the case of a large mass of the turbine 400, for example, the turbine 400 is made of a metal material, and in order to locate the center of gravity of the entire rotor system between the first radial bearing 600 and the second radial bearing 700, the embodiment shown in fig. 5 or fig. 6 may be adopted.
When the mass of the turbine 400 is small, for example, the material of the turbine 400 is a ceramic material or a ceramic fiber composite material, the embodiment shown in fig. 7 may be adopted in order to locate the center of gravity of the entire rotor system between the first radial bearing 600 and the second radial bearing 700.
In the embodiment shown in fig. 7, since the thrust bearing 500 is provided between the motor 200 and the compressor 300, the embodiment shown in fig. 7 is applied to the thrust bearing 500 having a small diameter of the thrust disk in order to prevent the thrust disk of the thrust bearing 500 from blocking the air inlet of the compressor 300.
at present, the non-contact bearing generally includes an electromagnetic bearing and an air bearing. However, the electromagnetic bearing has the problems of too large energy consumption, heat generation and the like when being started for a long time; when the surface linear velocity of the air bearing is close to or exceeds the sonic velocity, shock waves can be generated, so that the bearing is unstable, and even disastrous results such as shaft collision and the like are generated.
therefore, in consideration of the development requirement of high rotation speed of the gas turbine or the gas turbine generator set, in order to improve the working performance of the thrust bearing and the radial bearing, in an embodiment of the present invention, the thrust bearing 500 may be a gas-magnetic hybrid thrust bearing, and the first radial bearing 600 may be a gas-magnetic hybrid radial bearing or a gas hybrid radial bearing.
In addition, since the second radial bearing 700 is close to the turbine 400, the second radial bearing 700 may employ a hybrid gas hybrid radial bearing in consideration that the magnetic components of the magnetic bearings cannot withstand the high temperature transmitted from the turbine 400.
In another embodiment, the second radial bearing 700 may also be a hybrid gas-magnetic radial bearing, in which case the magnetic components of the second radial bearing 700 are arranged on the second radial bearing 700 in a region remote from the turbine 400. That is, the second radial bearing 700 is not provided with magnetic components in the region close to the turbine 400.
To protect the magnetic components of the second radial bearing 700, this may be accomplished by reducing the amount of heat energy radiated from the turbine 400 onto the second radial bearing 700. Specifically, the turbine 400 is provided with a thermal shield (not shown) on a side thereof adjacent to the second radial bearing 700. Here, the material of the thermal insulation layer may be aerogel or other material having good thermal insulation properties.
fig. 8 to 10 show a schematic representation of the arrangement of magnetic components on the second radial bearing 700 of fig. 5 to 7 in a region remote from the turbine 400.
The compressor 300 can be a centrifugal compressor 300, and the turbine 400 can be a centrifugal turbine; the motor 200 may be a dynamic pressure bearing motor, and a first dynamic pressure generating groove 201 may be provided at a portion of the rotating shaft 100 corresponding to a bearing of the motor 200.
As shown in fig. 11 to 14, the rotor system includes:
the rotating shaft 100, the shaft body of the rotating shaft 100 is an integral structure, and the rotating shaft 100 is horizontally arranged;
A motor 200, a compressor 300 and a turbine 400 sequentially arranged on the rotating shaft 100;
and a thrust bearing 500, a first radial bearing 600, a second radial bearing 700 and a third radial bearing 800 which are arranged on the rotating shaft 100, wherein the first radial bearing 600 is arranged on one side of the motor 200 far away from the compressor 300, the second radial bearing 700 is arranged between the compressor 300 and the turbine 400, and the third radial bearing 800 is arranged between the motor 200 and the compressor 300.
The thrust bearing 500 is disposed between the first radial bearing 600 and the motor 200, as shown in fig. 11; alternatively, the thrust bearing 500 is disposed on a side of the first radial bearing 600 away from the motor 200, as shown in fig. 12; alternatively, the thrust bearing 500 is disposed between the motor 200 and the compressor 300, as shown in fig. 13 or 14.
due to the addition of the third radial bearing 800, when the thrust bearing 500 is disposed between the motor 200 and the compressor 300, the thrust bearing 500 may be disposed between the motor 200 and the third radial bearing 800, as shown in fig. 13; the thrust bearing 500 may in turn be disposed between the third radial bearing 800 and the compressor 300, as shown in fig. 14.
The stability of the entire rotor system can be further improved by adding a third radial bearing 800 between the motor 200 and the compressor 300.
In the embodiment of the present invention, the thrust bearing 500 may adopt a gas magnetic hybrid thrust bearing, and the first radial bearing 600 may adopt a gas magnetic hybrid radial bearing or a gas hybrid radial bearing; since the second radial bearing 700 is close to the turbine 400, the second radial bearing 700 may employ a hybrid gas hybrid radial bearing in consideration of the fact that magnetic components included in the magnetic bearings cannot withstand high temperatures transmitted from the turbine 400.
In another embodiment, the second radial bearing 700 may also be a hybrid gas-magnetic radial bearing, in which case the magnetic components of the second radial bearing 700 are arranged on the second radial bearing 700 in a region remote from the turbine 400. That is, the second radial bearing 700 is not provided with magnetic components in the region close to the turbine 400.
to protect the magnetic components of the second radial bearing 700, this may be accomplished by reducing the amount of heat energy radiated from the turbine 400 onto the second radial bearing 700. Specifically, the turbine 400 is provided with a thermal shield (not shown) on a side thereof adjacent to the second radial bearing 700. Here, the insulation layer may be aerogel or other material.
Fig. 15 to 18 show a schematic representation of the arrangement of magnetic components on the second radial bearing 700 of fig. 11 to 14 in a region remote from the turbine 400.
as shown in fig. 19, the rotor system includes:
The rotating shaft 100, the shaft body of the rotating shaft 100 is an integral structure, and the rotating shaft 100 is horizontally arranged;
a motor 200, a compressor 300 and a turbine 400 sequentially arranged on the rotating shaft 100;
And a thrust bearing 500, a first radial bearing 600, a second radial bearing 700 and a fourth radial bearing 900 which are arranged on the rotating shaft 100, wherein the first radial bearing 600 is arranged on one side of the motor 200 far away from the compressor 300, the second radial bearing 700 is arranged between the compressor 300 and the turbine 400, the fourth radial bearing 900 is arranged on one side of the turbine 400 far away from the compressor 300, and the thrust bearing 500 is arranged between the compressor 300 and the second radial bearing 700.
Embodiments of the present invention may be applicable to the situation where the mass of the motor 200 is too large, and when the mass of the motor 200 is too large, radial bearings (i.e. the first radial bearing 600 and the fourth radial bearing 900) need to be arranged at both ends of the rotor system in order to maintain the stability of the rotor system, and the thrust bearing 500 needs to move towards one side of the turbine 400.
in consideration of the high temperature of the turbine 400, when the thrust bearing 500 is a gas-magnetic hybrid thrust bearing, the thrust bearing 500 may be disposed between the compressor 300 and the second radial bearing 700 because the magnetic components in the magnetic bearings cannot withstand the high temperature transmitted from the turbine 400. Accordingly, the second radial bearing 700 may employ a hybrid gas hybrid radial bearing.
Generally, the temperature of the side of the turbine 400 near the fourth radial bearing 900 is higher than the temperature of the side of the turbine 400 near the second radial bearing 700, and therefore, the fourth radial bearing 900 is preferably a hybrid gas-hybrid radial bearing.
In another embodiment, the second radial bearing 700 may also be a hybrid gas-magnetic radial bearing, in which case the magnetic components of the second radial bearing 700 are arranged on the second radial bearing 700 in a region remote from the turbine 400. That is, the second radial bearing 700 is not provided with magnetic components in the region close to the turbine 400.
to protect the magnetic components of the second radial bearing 700, this may be accomplished by reducing the amount of heat energy radiated from the turbine 400 onto the second radial bearing 700. Specifically, the turbine 400 is provided with a thermal shield (not shown) on a side thereof adjacent to the second radial bearing 700. Here, the insulation layer may be aerogel or other material.
FIG. 20 illustrates a schematic view of the second radial bearing 700 of FIG. 19 with magnetic components located in a region away from the turbine 400.
It should be noted that when the mass of the motor 200 is not too large, the thrust bearing 500 may be disposed between the first radial bearing 600 and the motor 200; alternatively, the thrust bearing 500 may be disposed on a side of the first radial bearing 600 away from the motor 200; alternatively, the thrust bearing 500 may be disposed between the motor 200 and the compressor 300. This is not described in detail as it is readily understood.
As shown in fig. 21, the rotor system includes:
the rotating shaft 100, the shaft body of the rotating shaft 100 is an integral structure, and the rotating shaft 100 is horizontally arranged;
A motor 200, a compressor 300 and a turbine 400 sequentially arranged on the rotating shaft 100;
and a thrust bearing 500, a first radial bearing 600, a second radial bearing 700, a third radial bearing 800 and a fourth radial bearing 900 which are arranged on the rotating shaft 100, wherein the first radial bearing 600 is arranged on one side of the motor 200 far away from the compressor 300, the second radial bearing 700 is arranged between the compressor 300 and the turbine 400, the third radial bearing 800 is arranged between the motor 200 and the compressor 300, the fourth radial bearing 900 is arranged on one side of the turbine 400 far away from the compressor 300, and the thrust bearing 500 is arranged between the compressor 300 and the second radial bearing 700.
The third radial bearing 800 is added between the motor 200 and the compressor 300, so that the stability of the whole rotor system can be further improved.
In the embodiment of the present invention, the thrust bearing 500 may be a gas magnetic hybrid thrust bearing, and both the second radial bearing 700 and the fourth radial bearing 900 may be gas hybrid radial bearings.
In another embodiment, the second radial bearing 700 may also be a hybrid gas-magnetic radial bearing, in which case the magnetic components of the second radial bearing 700 are arranged on the second radial bearing 700 in a region remote from the turbine 400. That is, the second radial bearing 700 is not provided with magnetic components in the region close to the turbine 400.
To protect the magnetic components of the second radial bearing 700, this may be accomplished by reducing the amount of heat energy radiated from the turbine 400 onto the second radial bearing 700. Specifically, the turbine 400 is provided with a thermal shield (not shown) on a side thereof adjacent to the second radial bearing 700. Here, the insulation layer may be aerogel or other material.
FIG. 22 illustrates a schematic view of the second radial bearing 700 of FIG. 21 with magnetic components located in a region away from the turbine 400.
The rotor system of the gas turbine generator set 1 may also be a vertical rotor system: the shaft body of the first rotating shaft is of an integrated structure, and the first rotating shaft is vertically arranged; the first rotating shaft is further provided with a thrust bearing and at least two radial bearings, and the thrust bearing and the at least two radial bearings are non-contact bearings. The thrust bearing is arranged at a preset position on one side of the first turbine close to the compressor, and the preset position is a position which enables the gravity center of the rotor system to be located between two radial bearings which are farthest away from each other in the at least two radial bearings.
The rotating shafts in the horizontal rotor systems shown in fig. 5 to 22 are vertically arranged, so that a corresponding vertical rotor system can be formed, and in order to avoid repetition, the embodiment of the invention is not described in detail. The vertical rotor system can achieve the same technical effect as the horizontal rotor system, and the vertical arrangement of the rotor system can ensure that the gravity centers of all components are downward, thereby avoiding the problem caused by the cantilever shaft type structure due to the horizontal arrangement of the rotor system.
The rotor system of the gas turbine generator set 1 may also be a rotor system of the type: the shaft body of the first rotating shaft is of an integral structure, and the first rotating shaft is horizontally arranged or vertically arranged; the first rotating shaft is also provided with a thrust bearing and two radial bearings, and the thrust bearing and the two radial bearings are non-contact bearings; the rotor system further comprises a first casing and a second casing, and the first casing is connected with the second casing. The first motor, the thrust bearing and the two radial bearings are all arranged in the first casing, the gas compressor and the first turbine are all arranged in the second casing, and an impeller of the gas compressor and an impeller of the first turbine are arranged in the second casing in an abutting mode.
In the embodiment of the invention, the impeller of the compressor and the impeller of the turbine are arranged in a leaning manner, so that the axial length in the first casing is shortened, and the stability of the whole rotor system can be further improved.
in an embodiment of the present invention, the first casing and the second casing may be positioned and connected by a spigot (not shown), wherein the thrust bearing and all of the radial bearings may be disposed entirely within the first casing (which may be understood as a generator casing) and no bearings may be disposed within the second casing (which may be understood as a gas turbine casing). Therefore, only the machining precision of the part for arranging the bearing stator in the first casing is required to be ensured, and the part for connecting the bearing stator in the first casing can be finished by one-time clamping machining during assembly.
As shown in fig. 23 to 25, the rotor system includes:
The rotating shaft 100, the shaft body of the rotating shaft 100 is an integral structure, and the rotating shaft 100 is horizontally arranged;
The motor 200, the compressor 300, the turbine 400, the thrust bearing 500, the first radial bearing 600 and the second radial bearing 700 are arranged on the rotating shaft 100, and the thrust bearing 500, the first radial bearing 600 and the second radial bearing 700 are all non-contact bearings;
the first casing 801 is connected with the second casing 901, the motor 200, the thrust bearing 500, the first radial bearing 600 and the second radial bearing 700 are all arranged in the first casing 801, and the compressor 300 and the turbine 400 are all arranged in the second casing 901; the impeller of the compressor 300 and the impeller of the turbine 400 are disposed adjacent to each other in the second casing 901.
The first radial bearing 600 is disposed on a side of the motor 200 far from the second casing 901, and the second radial bearing 700 is disposed on a side of the motor 200 close to the second casing 901.
The thrust bearing 500 is disposed between the first radial bearing 600 and the motor 200, as shown in fig. 23; alternatively, the thrust bearing 500 is disposed between the motor 200 and the second radial bearing 700, as shown in fig. 24; alternatively, the thrust bearing 500 is disposed on a side of the second radial bearing 700 close to the second casing 901, as shown in fig. 25.
in the embodiment shown in fig. 25, since the thrust bearing 500 is disposed on the side of the second radial bearing 700 close to the second casing 901, that is, the thrust bearing 500 is disposed close to the compressor in the second casing 901, the embodiment shown in fig. 25 is applied to the thrust bearing 500 having a small thrust disk diameter in order to prevent the thrust disk of the thrust bearing 500 from blocking the air inlet of the compressor 300.
Optionally, the bearing capacity of the second radial bearing 700 is greater than the bearing capacity of the first radial bearing 600.
In the embodiment of the present invention, generally, the weight of the motor 200 and the weight of the thrust bearing 500 are large, and the center of gravity of the entire rotor system is biased to the first radial bearing 600 side. In view of this, increasing the bearing capacity of the second radial bearing 700 helps to increase the stability of the entire rotor system.
In the embodiment of the present invention, the compressor 300 may be a centrifugal compressor 300, and the turbine of the turbine 400 may be a centrifugal turbine; the bearing of the motor 200 may be a hydrodynamic bearing, and a portion of the rotating shaft 100 corresponding to the bearing of the motor 200 may be provided with a first dynamic pressure generating groove 201.
The rotating shafts in the rotor systems shown in fig. 23 to 25 are vertically arranged, so that a corresponding vertical rotor system can be formed, and in order to avoid repetition, the embodiment of the present invention is not described in detail.
The first motor 12 shown in fig. 1 is the same motor as the motor 200 shown in fig. 5 to 25.
The operation of the gas turbine power plant will be described in detail below.
as shown in the foregoing, the thrust bearing in the rotor system may adopt a gas-magnetic hybrid thrust bearing, and the radial bearing may adopt a gas-magnetic hybrid thrust bearing or a gas hybrid radial bearing. For convenience of description, a bearing which can perform a lubrication function without rotating the rotating shaft 100 is defined as a hydrostatic bearing, and a bearing which can operate only when the rotating shaft 100 rotates to a certain speed is defined as a hydrodynamic bearing. According to the logic, a magnetic bearing and a gas hydrostatic bearing in the gas-magnetic hybrid thrust bearing and a gas hydrostatic bearing in the gas hybrid dynamic and static pressure radial bearing can be called as hydrostatic bearings; the gas dynamic pressure bearing in the gas-magnetic hybrid thrust bearing and the gas dynamic pressure bearing in the gas dynamic-static hybrid radial bearing can be called as dynamic pressure bearings.
The embodiment of the invention provides a control method of a gas turbine generator set, which comprises the following steps:
And S21, opening a hydrostatic bearing in the radial bearing and the thrust bearing to move the rotating shaft to a preset radial position and move the thrust disc of the thrust bearing to a preset axial position.
Wherein, opening the hydrostatic bearing includes: opening magnetic bearings in the bearings and/or delivering gas to static pressure inlet orifices in the bearings.
S22, starting a gas turbine generator set, compressing air by a compressor, and then entering a combustion chamber to mix and combust with fuel in the combustion chamber; the high-temperature high-pressure gas discharged from the combustion chamber impacts a turbine of the turbine to rotate the turbine, and the turbine drives the motor to rotate through the rotating shaft to generate power.
The starting process of the gas turbine generator set is specifically described below by taking the motor as an example for starting the integrated motor.
After receiving the start signal, a gas turbine controller (Electronic Control Unit, abbreviated as ECU) sends a motor driving mode command to a motor power controller (Data Processing Center, abbreviated as DPC); and switching the DPC to a motor driving mode, carrying out frequency conversion on the direct current of the built-in battery of the gas turbine by the DPC, driving the motor to work, and driving the gas turbine to increase the rotating speed by the motor.
And opening the fuel valve after the rotating speed of the gas turbine is increased to the ignition rotating speed, and entering an ignition program. Air enters the air compressor from the air inlet channel to be compressed and then enters the heat regenerator and is preheated by high-temperature gas exhausted from the turbine, the preheated compressed air enters the combustion chamber to be mixed with fuel and combusted, the high-temperature high-pressure gas after the combustion chamber is fully combusted enters the turbine to impact the turbine, so that the turbine of the turbine rotates, the cold compressed air before entering the combustion chamber is preheated by the exhaust pipe after the turbine exhausts, and the turbine drives the air compressor to rotate together to the self-sustaining speed due to the fact that the turbine is connected with the air compressor and the motor through the rotating shaft.
After the gas turbine reaches the self-sustaining rotating speed, the DPC is hung up, the motor idles and continues to increase the accelerator, and the turbine continues to increase the power, so that the rotating speed is increased to the working rotating speed. The ECU sends a generator mode command to the DPC; the DPC is switched to a generator mode, and alternating current output by the motor is rectified and transformed to output voltage and current required by a user.
The compressor is a centrifugal compressor which comprises movable blades and static blades arranged along the circumferential direction, and the static blades are diffusers. Thus, the specific process of the air entering the compressor from the air inlet channel for compression can be as follows: after air enters a movable blade of the centrifugal compressor and is compressed, the air enters a diffuser (namely a static blade) arranged along the circumferential direction and is continuously compressed.
wherein the turbine is a centrifugal turbine provided with moving blades. The combustion chamber outlet is circumferentially arranged with stationary vanes, which are nozzles. Therefore, the high-temperature and high-pressure gas after the combustion chamber is fully combusted enters the turbine to do work, and the specific process of rotating the turbine can be as follows: the high-temperature and high-pressure gas that has been sufficiently combusted in the combustion chamber is expanded and accelerated by a nozzle (i.e., a stationary blade) arranged in the circumferential direction at the combustion chamber outlet, and then impacts the movable blade of the turbine to rotate the turbine.
And S23, after the rotating speed of the rotating shaft is accelerated to the working rotating speed, closing the static pressure bearing in the radial bearing and the thrust bearing.
wherein closing the hydrostatic bearing comprises: closing the magnetic bearings in the bearings and/or stopping the delivery of gas to the static pressure intake orifices in the bearings.
And S24, when the gas turbine generator set stops, opening a hydrostatic bearing in the radial bearing and a hydrostatic bearing in the thrust bearing.
and S25, closing the static pressure bearing in the radial bearing and the thrust bearing after the rotating speed of the rotating shaft is reduced to zero.
in the above process, the bearings in the rotor system are controlled so that the hydrostatic bearings in the radial bearing and the thrust bearing are opened until the rotation speed of the rotating shaft reaches the working rotation speed.
when the gas turbine generator set stops, the bearings in the rotor system are controlled, and the hydrostatic bearings in the radial bearing and the thrust bearing are enabled to be opened until the rotating speed of the rotating shaft is zero.
The embodiment of the invention provides another control method of a gas turbine generator set, which comprises the following steps:
And S31, opening a hydrostatic bearing in the radial bearing and the thrust bearing to move the rotating shaft to a preset radial position and move the thrust disc of the thrust bearing to a preset axial position.
Wherein, opening the hydrostatic bearing includes: opening magnetic bearings in the bearings and/or delivering gas to static pressure inlet orifices in the bearings.
S32, starting a gas turbine generator set, compressing air by a compressor, and then entering a combustion chamber to mix and combust with fuel in the combustion chamber; the high-temperature high-pressure gas discharged from the combustion chamber impacts a turbine of the turbine to rotate the turbine, and the turbine drives the motor to rotate through the rotating shaft to generate power.
And S33, 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.
Wherein the first preset value may be 5% to 30% of the rated rotation speed.
Wherein closing the hydrostatic bearing comprises: closing the magnetic bearings in the bearings and/or stopping the delivery of gas to the static pressure intake orifices in the bearings.
And S34, when the rotor system accelerates to a first-order critical speed or a second-order critical speed, the hydrostatic bearings in the radial bearing and the thrust bearing are started.
And S35, closing the static pressure bearings in the radial bearing and the thrust bearing after the rotor system smoothly passes the first-order critical speed or the second-order critical speed.
And S36, in the shutdown process of the gas turbine generator set, when the rotor system decelerates to a first-order critical speed or a second-order critical speed, the hydrostatic bearings in the radial bearing and the thrust bearing are started.
And S37, closing the static pressure bearings in the radial bearing and the thrust bearing after the rotor system smoothly passes the first-order critical speed or the second-order critical speed.
And S38, when the rotating speed of the rotating shaft is reduced to a second preset value, opening a hydrostatic bearing in the radial bearing and a hydrostatic bearing in the thrust bearing.
The second preset value may be equal to the first preset value or not, and the second preset value may be 5% to 30% of the rated rotation speed.
And S39, closing the static pressure bearing in the radial bearing and the thrust bearing after the rotating speed of the rotating shaft is reduced to zero.
In the process, before the gas turbine generator set is started, the bearings in the rotor system are controlled, and the hydrostatic bearings of the radial bearing and the thrust bearing are opened. Thus, the rotating shaft is supported to a preset radial position under the action of a 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 gas turbine generator set 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% to 30% of the rated rotating speed, the bearings in the rotor system are controlled, so that the static pressure bearings in the radial bearing and the thrust bearing stop working. When the rotating speed of the rotating shaft reaches a first-order critical speed or a second-order critical speed, the bearings in the rotor system are controlled, and the hydrostatic bearings of the radial bearing and the thrust bearing are restarted. And after the rotating speed of the rotating shaft stably passes the first-order critical speed or the second-order critical speed, controlling the bearings in the rotor system to enable the hydrostatic bearings in the radial bearing and the thrust bearing to stop working again.
And when the rotating speed of the rotating shaft reaches a second-order critical speed or a first-order critical speed, controlling a bearing in the rotor system to open the hydrostatic bearings of the radial bearing and the thrust bearing again. And after the rotating speed of the rotating shaft smoothly passes through the second-order critical speed or the first-order critical speed, controlling the bearings in the rotor system to stop the static pressure bearings in the radial bearing and the thrust bearing again. When the rotating speed of the rotating shaft is reduced to a preset value, for example, 5% to 30% of the rated rotating speed, the bearings in the rotor system are controlled, the hydrostatic bearings of the radial bearing and the thrust bearing are opened again until the rotating speed is reduced to zero, and then the bearings in the rotor system are controlled, and the hydrostatic bearings of the radial bearing and the thrust bearing are stopped again.
The following describes a control method of the rotor system specifically based on the control method of the gas turbine generator set.
The embodiment of the invention provides a control method of a rotor system, which comprises the following steps:
s101, starting a hydrostatic bearing in the radial bearing and the thrust bearing to enable the rotating shaft to move to a preset radial position and enable a thrust disc of the thrust bearing to move to a preset axial position.
Wherein, opening the hydrostatic bearing includes: opening magnetic bearings in the bearings and/or delivering gas to static pressure inlet orifices in the bearings.
And S102, closing the hydrostatic bearings in the radial bearing and the thrust bearing after the rotating speed of the rotating shaft is accelerated to the working rotating speed.
Wherein closing the hydrostatic bearing comprises: closing the magnetic bearings in the bearings and/or stopping the delivery of gas to the static pressure intake orifices in the bearings.
And S103, when the rotor system is stopped, starting a hydrostatic bearing in the radial bearing and a hydrostatic bearing in the thrust bearing.
And S104, closing the hydrostatic bearings in the radial bearing and the thrust bearing after the rotating speed of the rotating shaft is reduced to zero.
in the process, before the rotor system is started, the bearings in the rotor system are controlled, and the hydrostatic bearings of the radial bearing and the thrust bearing are opened. Thus, the rotating shaft is supported to a preset radial position under the action of a 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. And the hydrostatic bearings in the radial bearing and the thrust bearing are opened until the rotating speed of the rotating shaft reaches the working rotating speed.
When the rotor system stops, the bearings in the rotor system are controlled, and the hydrostatic bearings in the radial bearing and the thrust bearing are enabled to be started until the rotating speed of the rotating shaft is zero.
The embodiment of the invention provides another control method of a rotor system, which comprises the following steps:
s201, starting a hydrostatic bearing in the radial bearing and the thrust bearing to enable the rotating shaft to move to a preset radial position and enable a thrust disc of the thrust bearing to move to a preset axial position.
Wherein, open hydrostatic bearing includes: opening magnetic bearings in the bearings and/or delivering gas to static pressure inlet orifices in the bearings.
S202, after the rotating speed of the rotating shaft is accelerated to a first preset value, closing a hydrostatic bearing in the radial bearing and the thrust bearing.
Wherein the first preset value may be 5% to 30% of the rated rotation speed.
Wherein closing the hydrostatic bearing comprises: closing the magnetic bearings in the bearings and/or stopping the delivery of gas to the static pressure intake orifices in the bearings.
and S203, when the rotor system is accelerated to a first-order critical speed or a second-order critical speed, starting hydrostatic bearings in the radial bearing and the thrust bearing.
and S204, after the rotor system passes through the first-order critical speed or the second-order critical speed in a smooth mode, closing the static pressure bearings in the radial bearing and the thrust bearing.
and S205, when the rotor system decelerates to a first-order critical speed or a second-order critical speed, starting hydrostatic bearings in the radial bearing and the thrust bearing.
And S206, after the rotor system passes through the first-order critical speed or the second-order critical speed in a smooth mode, closing the static pressure bearings in the radial bearing and the thrust bearing.
And S207, when the rotating speed of the rotating shaft is reduced to a second preset value, starting a hydrostatic bearing in the radial bearing and a hydrostatic bearing in the thrust bearing.
the second preset value may be equal to the first preset value or not, and the second preset value may be 5% to 30% of the rated rotation speed.
And S208, closing the hydrostatic bearings in the radial bearing and the thrust bearing after the rotating speed of the rotating shaft is reduced to zero.
in the process, before the rotor system is started, the bearings in the rotor system are controlled, and the hydrostatic bearings of the radial bearing and the thrust bearing are opened. Thus, the rotating shaft is supported to a preset radial position under the action of a 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 rotor system 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% to 30% of the rated rotating speed, the bearings in the rotor system are controlled, so that the static pressure bearings in the radial bearing and the thrust bearing stop working. When the rotating speed of the rotating shaft reaches a first-order critical speed or a second-order critical speed, the bearings in the rotor system are controlled, and the hydrostatic bearings of the radial bearing and the thrust bearing are restarted. And after the rotating speed of the rotating shaft stably passes the first-order critical speed or the second-order critical speed, controlling the bearings in the rotor system to enable the hydrostatic bearings in the radial bearing and the thrust bearing to stop working again.
And in the stopping process of the rotor system, the rotating speed of the rotating shaft is gradually reduced, and when the rotating speed of the rotating shaft reaches the second-order critical speed or the first-order critical speed, the bearings in the rotor system are controlled to enable the hydrostatic bearings of the radial bearing and the thrust bearing to be started again. And after the rotating speed of the rotating shaft smoothly passes through the second-order critical speed or the first-order critical speed, controlling the bearings in the rotor system to stop the static pressure bearings in the radial bearing and the thrust bearing again. When the rotating speed of the rotating shaft is reduced to a preset value, for example, 5% to 30% of the rated rotating speed, the bearings in the rotor system are controlled, the hydrostatic bearings of the radial bearing and the thrust bearing are opened again until the rotating speed is reduced to zero, and then the bearings in the rotor system are controlled, and the hydrostatic bearings of the radial bearing and the thrust bearing are stopped again.
In the embodiment of the present invention, the radial bearing in the rotor system of the gas turbine generator set 1 is preferably an air-magnetic hybrid radial bearing, and the thrust bearing in the rotor system of the gas turbine generator set 1 is preferably an air-magnetic hybrid thrust bearing.
Accordingly, the radial bearings in ORC system 61 are preferably air-magnetic hybrid radial bearings and the thrust bearings in ORC system 61 are preferably air-magnetic hybrid thrust bearings.
In the embodiment of the invention, the structural form of the air-magnetic hybrid radial bearing and the air-magnetic hybrid thrust bearing can be implemented in various ways.
Wherein, the gas-magnetic mixed radial bearing can adopt a foil type gas-magnetic mixed radial bearing.
Other specific structures of the foil type gas-magnetic hybrid radial bearing can be referred to related descriptions in patent application documents with application numbers CN201810030888.1, CN201810030299.3, or CN201810031822.4, and can achieve the same beneficial effects, and in order to avoid repetition, the embodiments of the present invention are not described in detail herein.
Wherein, the gas-magnetic hybrid thrust bearing can adopt a foil type gas-magnetic hybrid thrust bearing.
As shown in fig. 26 to 29, the foil-type air-magnetic hybrid thrust bearing 5100 includes:
The first thrust disc 5101, the first thrust disc 5101 is fixedly connected to the rotating shaft 100;
The first stator 5102 and the second stator 5103 penetrate through the rotating shaft 100, and the first stator 5102 and the second stator 5103 are respectively arranged on two opposite sides of the first thrust disc 5101;
each of the first stator 5102 and the second stator 5103 includes a first magnetic bearing 5104 and a first foil bearing 5105, the first magnetic bearing 5104 is provided with a plurality of first magnetic components along a circumferential direction, and the first foil bearing 5105 is provided with a second magnetic component capable of generating a magnetic force with the plurality of first magnetic components;
the first foil bearing 5105 is disposed between the first magnetic bearing 5104 and the first thrust disk 5101, and has a first gap 5106 with the first thrust disk 5101, and the first foil bearing 5105 is capable of moving in the axial direction of the rotating shaft 100 under the action of magnetic force between the first magnetic member and the second magnetic member.
in the embodiment of the present invention, the thrust bearing 5100 is formed as a hybrid gas-magnetic thrust bearing by providing a first gap 5106 and a first magnetic bearing 5104 in the thrust bearing 5100.
during operation, the gas bearing in the thrust bearing 5100 and the first magnetic bearing 5104 can work in cooperation, and when the thrust bearing 5100 is in a stable working state, the gas bearing is used for supporting; when the thrust bearing 5100 is in an unstable working state, the thrust bearing 5100 is controlled and responded 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 of the embodiment of the invention can meet the requirements of a rotor system with high rotating speed, such as a gas turbine or a gas turbine power generation combined unit.
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 rotor system of the embodiment of the present invention is applied to a gas turbine or a gas turbine power generation combined unit, the first stator 5102 and the second stator 5103 may be connected to a housing of the gas turbine through a connection member.
optionally, the plurality of first magnetic components comprise a plurality of first permanent magnets circumferentially disposed 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, and each of the plurality of first electromagnets includes 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 gas-magnetic hybrid thrust bearing 5100 only requires the magnetic member to provide magnetic force and does not require magnetic control, the first magnetic member is preferably a first permanent magnet; when the foil gas-magnetic hybrid thrust bearing 5100 requires both magnetic force and magnetic control, the first magnetic member 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 flowing into 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 the current flowing to the first coil 51042 is different, and the magnetic pole of the first magnetic core 51041 is 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 properties such as high magnetic permeability and low eddy current loss.
Optionally, the first magnetic bearing 5104 includes:
the first magnetic bearing base 51043 is arranged opposite to the first thrust disc 5101, a plurality of first accommodating grooves 51044 are circumferentially arranged on the first magnetic bearing base 51043, a plurality of first magnetic components are arranged in the first accommodating grooves 51044, and magnetic poles of the plurality of first magnetic components face one side where the first foil bearing 5105 is located;
the first end cap 51045 is disposed on a side of the first magnetic bearing holder 51043 away from the first foil bearing 5105, and is engaged with the first foil bearing 5105 to fix the first magnetic member to the first magnetic bearing holder 51043.
In the preferred embodiment of the present invention, the first magnetic bearing base 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 properties such as high magnetic permeability and low eddy current loss. The number of the first receiving grooves 51044 may be, but is not limited to, six or eight, and is uniformly arranged along the circumferential direction of the first magnetic bearing holder 51043. In this way, the magnetic force between the first magnetic bearing holder 51043 and the first foil bearing 5105 can be made more uniform and stable. The plurality of first magnetic members may be provided on the first magnetic bearing holder 51043 in other manners, which is not limited. 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;
The first foil 51052 and the second foil 51053 are arranged on the first foil bearing seat 51051, the first foil 51052 is arranged on the first foil bearing seat 51051, and the second foil 51053 is overlapped on one side, close to the first thrust plate 5101, of the first foil 51052;
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 action of the first magnetic component and the second magnetic component; the first foil 51052 is an elastically deformable foil that is capable of elastically deforming when the second foil 51053 is moved.
Wherein the material of the first foil bearing mount 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 band that is not magnetically permeable, considering that the material of the magnetically permeable material is hard and brittle and is not suitable for the elastically deformable foil.
In the embodiment of the present invention, the second foil 51053 is provided as a flat foil, so that the distance between the second foil 51053 and the first thrust plate 5101 is conveniently controlled, or the size of the first gap 5106 is conveniently controlled. The first foil 51052 is made of an elastically deformable foil, which serves to connect the second foil 51053 and the first foil bearing seat 51051, and on the other hand, the second foil 51053 is movable relative to the first foil bearing seat 51051 in the axial direction of the rotating shaft 100.
Optionally, the first foil 51052 is a wavy elastically deformable foil, and the first foil 51052 is an unclosed 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;
In this case, when the second foil 51053 moves in the axial direction of the rotating shaft 100, the wave pattern on the first foil 51052 expands or contracts, and the movable end moves in the circumferential direction of the ring shape.
In the embodiment of the present invention, the first foil 51052 is provided as an elastically deformable foil having a wavy shape, so that the second foil 51053 is pushed to move in the axial direction of the rotating shaft 100 by the stretching or shrinking characteristics of the wavy veins.
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 applied to the first foil 51052 in the embodiment of the present invention.
Alternatively, the second magnetic member includes a first magnetic material disposed on a side surface of the second foil 51053 adjacent 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 portions, and the plurality of strip-shaped magnetic portions are radial or annular;
Alternatively, the first magnetic elements are distributed in dots on the second foils 51053.
The second foil 51053 is preferably made of a non-magnetic material, and after the first magnetic material is sprayed on the surface of the second foil 51053, 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 is completely covered with the first magnetic material, the magnetic force generated between the first magnetic material and the first magnetic member is greatly increased, which easily causes the second foil 51053 to be deformed. In view of this, in the embodiment of the present invention, the first magnetic material is sprayed on the surface of the second foil 51053, so that the first magnetic material is distributed in a stripe shape or a dot shape on the second foil 51053, and the magnetic force generated between the first magnetic material and the first magnetic component can be controlled within a reasonable range, thereby preventing the second foil 51053 from being deformed due to an excessive magnetic force.
optionally, the foil 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, such as the air film pressure at the first gap 5106, can be detected in real time. In this way, the first magnetic bearing 5104 can actively control the thrust bearing 5100 based on the detection result of the first sensor 5107, and can achieve high accuracy in control.
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 a first magnetic bearing 5104, and through holes for the first sensor probe 51072 to pass through are formed in 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 of 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 close to the first thrust plate 5101.
In the embodiment of the present invention, the first sensor 5107 can be more stably mounted to the first magnetic bearing 5104 by the structural form and mounting manner of the first sensor 5107. The second end of the first sensor probe 51072 is flush with the side of the first foil bearing 5105 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 therefore the first sensor probe 51072 can be protected; on the other hand, the air film in the first gap 5106 is not affected, and the air film in the first gap 5106 is prevented from being disturbed.
Optionally, the first sensor 5107 is disposed between two adjacent first magnetic components.
In the embodiment of the present invention, at least one first sensor 5107, preferably one first sensor 5107, is disposed on each stator, and the first sensor 5107 is preferably disposed between two adjacent first magnetic components.
Optionally, the first sensor 5107 is any one or combination of:
A displacement sensor for detecting the position of the first thrust plate 5101;
a pressure sensor for detecting the air film pressure at the first gap 5106;
a speed sensor for detecting the rotation speed of the first thrust plate 5101;
An acceleration sensor for detecting the rotational acceleration of the first thrust plate 5101.
A specific control method of the embodiment of the present invention when the foil gas-magnetic hybrid thrust bearing (in which the first magnetic component in the first magnetic bearing is an electromagnet) participates in the control process of the rotor system will be described in detail below.
the embodiment of the invention provides a control method of a foil type gas-magnetic hybrid thrust bearing, which comprises the following steps:
And S511, starting a first magnetic bearing 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 the difference value between a first gap between the first thrust disc and a first foil bearing in the first stator and a first gap between the first thrust disc and the first foil bearing in the second stator is smaller than or equal to a preset value.
And S512, after the rotating speed of the rotating shaft is accelerated to the working rotating speed, closing the first magnetic bearings in the first stator and the second stator.
and S513, when the rotor system is stopped, starting the first magnetic bearings in the first stator and the second stator.
and S514, after the rotating speed of the rotating shaft is reduced to zero, closing the first magnetic bearing in the first stator and the second stator.
In the process, after the first magnetic bearing is started, the first thrust disc reaches a preset position between the first stator and the second stator under the action of the first magnetic bearing, and first gaps are formed among the first thrust disc, the first stator and the end face of the second stator.
as the rotating shaft rotates, the first thrust disc starts to rotate relative to the first stator and the second stator while being lubricated by the air flow in the first gap to prevent wear. The specific process of starting the first magnetic bearing is as follows: a current signal with a preset value is input into the first coil, and the first thrust disc reaches a preset position between the first stator and the second stator under the action of the first magnetic bearing.
with the increasing of the rotating speed of the rotating shaft, the rotating speed of the first thrust disc is synchronously increased, when the rotating speed of the rotating shaft reaches the working rotating speed, the first thrust disc can be stabilized by the air film pressure generated by the aerodynamic pressure bearing of the thrust bearing (the first thrust disc, the first stator and the second stator are provided with the first gap, namely the aerodynamic pressure bearing of the thrust bearing is formed), and then the first magnetic bearing can be closed.
When the rotor system stops, the first thrust disc decelerates along with the deceleration of the rotating shaft, and in order to keep the rotating shaft stable in the whole rotor system stopping process, the first magnetic bearing is started when the rotor system stops, and the first magnetic bearing is closed until the first thrust disc completely stops.
The embodiment of the invention also provides another control method of the foil type gas-magnetic hybrid thrust bearing, which comprises the following steps:
And S521, starting a first magnetic bearing 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 the difference between a first gap between the first thrust disc and a first foil bearing in the first stator and a first gap between the first thrust disc and the first foil bearing in the second stator is smaller than or equal to a preset value.
And S522, after the rotating speed of the rotating shaft is accelerated to the first preset value, closing the first magnetic bearing in the first stator and the second stator.
And S523, when the rotating speed of the rotating shaft is reduced to a second preset value, starting a first magnetic bearing in the first stator and the second stator.
and S524, after the rotating speed of the rotating shaft is reduced to zero, closing the first magnetic bearing in the first stator and the second stator.
In the process, after the first magnetic bearing is started, the first thrust disc reaches a preset position between the first stator and the second stator under the action of the first magnetic bearing, and first gaps are formed among the first thrust disc, the first stator and the end face of the second stator.
As the rotating shaft rotates, the first thrust disc starts to rotate relative to the first stator and the second stator while being lubricated by the air flow in the first gap to prevent wear. The specific process of starting the first magnetic bearing is as follows: a current signal with a preset value is input into the first coil, and the first thrust disc reaches a preset position between the first stator and the second stator under the action of the first magnetic bearing.
As the rotating speed of the rotating shaft is increased, the rotating speed of the first thrust disc is also increased synchronously, and when the rotating speed of the rotating shaft reaches a first preset value, for example, 5% to 30% of the rated rotating speed, the first thrust disc can be stabilized by the air film pressure generated by the aerodynamic bearing of the thrust bearing (the aerodynamic bearing which is provided with the first gap between the first thrust disc and the first stator and the second stator, that is, the foil type aerodynamic hybrid thrust bearing is formed), and at the moment, the first magnetic bearing can be closed.
During the shutdown process of the rotor system, the first thrust disc decelerates 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, at this time, the air film pressure generated by the aerodynamic bearing of the thrust bearing also decreases along with the deceleration of the first thrust disc, so that the first magnetic bearing needs to be opened to keep the first thrust disc stable, and the first magnetic bearing can be closed until the first thrust disc completely stops.
optionally, the method further includes:
When a load is loaded on 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 difference value between a first gap between the first thrust disc and the first foil bearing in the first stator and a first gap between the first thrust disc and the first foil bearing in the second stator is larger than a preset value, starting a first magnetic bearing in the first stator and the second stator;
The first magnetic bearing in the first and second stators is turned off when a difference between a first gap between the first thrust disc and the first foil bearing in the first stator and a first gap between the first thrust disc and the first foil bearing in the second stator is less than or equal to a predetermined value.
When a load is loaded 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 on that 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 interworked. The first magnetic bearing does not completely and directly apply magnetic force to the first thrust disc to enable the first thrust disc to move towards the first foil bearing on the other side, but uses the magnetic force to enable the first foil bearing on the other side to move towards the direction far away from the first thrust disc, so that the first gap between the first thrust disc and the first foil bearing on the other side is increased, the pressure on the side where the first gap is reduced is increased, the first magnetic bearing is adaptive to the weight of a load on the first thrust disc, and the airflow pressure on the two first gaps is automatically redistributed. When the first thrust disc reaches the new equilibrium position, the first magnetic bearing stops working.
Specifically, if a first gap between the first thrust disc and the first foil bearing in the first stator is smaller than a 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 force 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 the magnetic force between the plurality of first magnetic components and the second magnetic component.
Optionally, when a load is applied to the first thrust disc, the first thrust disc moves in the axial direction of the rotating shaft under the load, and a first gap between the first thrust disc and the first foil bearing in the first stator and a first gap between the first thrust disc and the first foil bearing in the second stator are both opened, the difference value of the opening of the first magnetic bearings in the first stator and the second stator is greater than a predetermined value, including:
when a load is loaded on 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 difference value between a first gap between the first thrust disc and the first foil bearing in the first stator and a first gap between the first thrust disc and the first foil bearing in the second stator is larger than a preset value, controlling the first magnetic bearings in the first stator and the second stator to be started at the maximum power; or,
And when the load is loaded on 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 difference value between a first gap between the first thrust disc and the first foil bearing in the first stator and a first gap between the first thrust disc and the first foil bearing in the second stator is larger than a preset value, controlling the first magnetic bearings in the first stator and the second stator to be opened in a stroboscopic mode according to a preset frequency.
When external impact disturbance occurs, the first thrust disc can be quickly close to the first foil bearing on one side, so that the first gap on the side is possibly over-small instantly, the local gas flow velocity at the first gap on the side is close to even reaches the sonic velocity, and the shock wave is caused to generate the self-excitation phenomenon of the air hammer. The generation of the shock wave causes turbulence and chaos in the local gas flow, with the pressure dropping dramatically in steps as the fluid velocity changes from sonic to subsonic. In this case, it is desirable that the side first foil bearing actively "dodge" the first thrust disk, thereby increasing the side first gap to maintain the gas flow velocity in the subsonic region as much as possible to maintain its normal fluid pressure. Specifically, the first magnetic bearings on the first stator and the second stator need to be controlled 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 suction for sucking back the first foil bearing on the side, and the side with the increased first gap generates suction for pulling back the first thrust disc. In this way, the difference of the acting distances of the magnetic forces on the two sides is utilized to generate a magnetic force difference, so that the first thrust disc is pulled to enable the first gap between the first thrust disc and the first foil bearings on the two sides to be normal, and the first thrust disc is enabled to return to the balance state again.
In the process, the first magnetic bearing is utilized to facilitate real-time control, and the first thrust disc is fixed in a certain minimum range in the axial direction of the rotating shaft by actively balancing the unbalanced mass of the first thrust disc or the factors causing excessive deviation of the first thrust disc, such as the whirling motion of the first thrust disc. In addition, in the acceleration process of the first thrust disc, the position where the shock wave is generated (namely the linear velocity supersonic speed part) can be accurately positioned, and the first magnetic bearing generates opposite force to balance the shock wave action by controlling the current magnitude, the current direction and the like of the first magnetic bearing. And after the shock wave is stable, adjusting the control strategy of the first magnetic bearing again, and fixing the first thrust disc in a certain minimum range in a 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 improved. Meanwhile, the electromagnetic bearing and the gas bearing are in a parallel connection 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 rotor system is started or stopped, the electromagnetic bearings can be used for enabling the thrust disc and the stator of the bearing to rotate in the bearing gap, the low-speed performance of the bearing is improved, the service life of the bearing is prolonged, and the safety and the reliability of the bearing and the whole system can be improved.
Compared with the traditional gas dynamic and static pressure hybrid thrust bearing adopting the combination of a gas static pressure bearing and a gas dynamic pressure bearing, the foil type gas-magnetic hybrid thrust bearing provided by the embodiment of the invention has the advantage of high response speed.
Thirdly, the magnetic material is arranged on the foil, the foil can be properly deformed through the attraction of the magnetic pole of the electromagnetic bearing, the highest pressure of one side of a lubricating air film in the bearing is improved, the lubricating air flow is prevented from leaking, the capability of the thrust disc for resisting the disturbance eccentric wall collision is improved, and the bearing capacity of the bearing is improved.
fourthly, a pressure sensor with lower cost is adopted to collect the pressure change of the air film, the deformation of the foil is controlled by a simple control method, and higher rotor damping can be provided, so that the stability of the rotor is improved. In addition, the control method is simple, and the requirement on the machining precision of the bearing is not high.
Wherein, the gas-magnetic hybrid thrust bearing can adopt a groove-type gas-magnetic hybrid thrust bearing.
As shown in fig. 30 to 36, the groove type air-magnetic hybrid thrust bearing 5200 includes:
A second thrust disk 5201, the second thrust disk 5201 is fixedly connected to the rotating shaft 100, and a third magnetic component is arranged on the second thrust disk 5201;
A third stator 5202 and a fourth stator 5203 which are arranged on the rotating shaft 100 in a penetrating way, wherein the third stator 5202 and the fourth stator 5203 are respectively arranged on two opposite sides of the second thrust plate 5201;
Each of the third stator 5202 and the fourth stator 5203 includes a second magnetic bearing 5204, the second magnetic bearing 5204 is provided with a plurality of fourth magnetic members capable of generating a magnetic force with the third magnetic member in the circumferential direction, 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 movable in the axial direction of the rotating shaft 100 by the magnetic force between the third magnetic member and the plurality of fourth magnetic members;
in this case, the end surfaces of the second thrust plate 5201 facing the third stator 5202 and the fourth stator 5203, or the end surfaces 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 present invention, the thrust bearing 5200 is formed into an air-magnetic hybrid thrust bearing by providing the second gap 5206 and the second magnetic bearing 5204 in the thrust bearing 5200.
During operation, the gas bearing in the thrust bearing 5200 and the second magnetic bearing 5204 can work together, and when the thrust bearing 5200 is in a stable operating state, the gas bearing is used for supporting; when the thrust bearing 5200 is in an unstable working state, the second magnetic bearing 5204 is used for controlling and responding to the thrust bearing 5200 in time.
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 of the embodiment of the invention can meet the requirements of a rotor system with high rotating speed, such as a gas turbine or a gas turbine power generation combined unit.
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 rotor system 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 a casing of the gas turbine by a connection member.
In the embodiment of the invention, when the second thrust plate 5201 is rotated, the flowing gas present in the second gap 5206 is pressed into the second dynamic pressure generating groove 5205, thereby generating a pressure to achieve non-contact holding of the second thrust plate 5201 in the axial direction. The pressure generated by the second dynamic pressure generating grooves 5205 varies depending on the angle, groove width, groove length, groove depth, number of grooves, and flatness of the second dynamic pressure generating grooves 5205. The magnitude of the pressure generated by the second dynamic pressure generating groove 5205 is also related to the rotation speed of the second thrust plate 5201 and the second gap 5206. The parameters of the second dynamic pressure generating groove 5205 may be designed according to 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, or punching, or the like, or the second dynamic pressure generating grooves 5205 may be formed on the second thrust plate 5201 by forging, rolling, etching, or punching, or the like.
optionally, the plurality of fourth magnetic components include a plurality of second permanent magnets, which are circumferentially disposed on the second magnetic bearing 5204;
Alternatively, the plurality of fourth magnetic members include a plurality of second electromagnets that are circumferentially disposed on the second magnetic bearing 5204, and each of the plurality of second electromagnets includes a second magnetic core 52041 disposed on the second magnetic bearing 5204 and a second coil 52042 wound around the second magnetic core 52041.
In the embodiment of the present invention, when the slot air-magnetic hybrid thrust bearing 5200 only requires the magnetic component to provide magnetic force and does not require magnetic control, the fourth magnetic component is preferably a second permanent magnet; when the slot air-magnetic hybrid thrust bearing 5200 requires both magnetic force and magnetic control, the fourth magnetic member is preferably a second electromagnet.
When the fourth magnetic member is the second electromagnet, the second magnetic core 52041 can generate a magnetic force by applying a current to the second coil 52042. The magnitude of the current applied to 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 the current flowing to the second coil 52042 is different and the magnetic pole of the second magnetic core 52041 is 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 properties such as high magnetic permeability and low eddy current loss.
Optionally, the second magnetic bearing 5204 includes:
a second magnetic bearing seat 52043, the second magnetic bearing seat 52043 is disposed opposite to the second thrust plate 5201, the second magnetic bearing seat 52043 is circumferentially provided with a plurality of second accommodation grooves 52044, the plurality of fourth magnetic members are disposed in the plurality of second accommodation grooves 52044, and magnetic poles of the plurality of fourth magnetic members face a side where the second thrust plate 5201 is located;
A second end cover 52045 and a first press ring 52046, wherein the second end cover 52045 is disposed on a side of the second magnetic bearing holder 52043 away from the second thrust plate 5201, the first press ring 52046 is disposed on a side of the second magnetic bearing holder 52043 close to the second thrust plate 5201, and the second end cover 52045 is fitted with the first press ring 52046 to fix the plurality of fourth magnetic members to the second magnetic bearing holder 52043.
In the preferred embodiment of the present invention, the second magnetic bearing seat 52043 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 properties such as high magnetic permeability and low eddy current loss. The number of the second accommodation grooves 52044 may be, but not limited to, six or eight, and are uniformly arranged along the circumferential direction of the second magnetic bearing holder 52043. In this way, the magnetic force between the second magnetic bearing 5204 and the second thrust plate 5201 can be made more uniform and stable. The plurality of fourth magnetic members may be provided on the second magnetic bearing base 52043 in another manner, but is not limited thereto. The material of the second end cover 52045 may be a non-magnetic material, preferably a duralumin material. The material of the first compression ring 52046 may be a non-magnetic material, preferably a duralumin material.
in the embodiment of the present invention, the second dynamic pressure generating groove 5205 may be provided on the first pressing ring 52046, and the first pressing ring 52046 may be made of a stainless material in order to facilitate the processing of the second dynamic pressure generating groove 5205.
Alternatively, the third magnetic member includes a second magnetic material (not shown in the drawings) provided 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 disk 5201 to form a plurality of strip-shaped magnetic portions, and the plurality of strip-shaped magnetic portions are radial or annular;
Alternatively, the second magnetic members are disposed 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 plate 5201, so that the magnetic force generated between the second magnetic material and the fourth magnetic member can be controlled within a reasonable range.
alternatively, the second dynamic pressure generating grooves 5205 may be arranged in a radial or concentric manner, which is advantageous for the gas film to be more uniformly distributed in the second gap 5206.
Alternatively, 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 an end of the first spiral groove 52051 near the second spiral groove 52052 is connected to or disconnected from an 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 close to 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 close to 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 axial center of the rotating 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 arrangement of the second dynamic pressure generating groove 5205, the second thrust plate 5201 can be held in a non-contact manner in a desired manner even when the rotating shaft 100 is rotating in the forward direction or in the reverse direction, so that the rotating shaft 100 has advantages of high load capacity and good stability.
optionally, in the third stator 5202 and the fourth stator 5203, each stator is further provided with a first static pressure intake orifice 5208, one end of the first static pressure intake orifice 5208 is communicated with the second gap 5206, and the other end 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, the first static pressure intake orifice 5208 is provided to form a gas static pressure bearing, and the thrust bearing 5200 can constitute a gas hybrid thrust bearing. The flow diameter of the first static pressure intake orifice 5208 can be adjusted according to actual conditions such as air quantity demand.
Alternatively, in the third stator 5202 and the fourth stator 5203, a plurality of first static pressure intake orifices 5208 are provided on each stator, and the plurality of first static pressure intake orifices 5208 are provided at intervals in the circumferential direction of the stator.
In the embodiment of the invention, the plurality of first static pressure intake orifices 5208 are provided at intervals in the circumferential direction of the stator, and preferably, at even intervals in the circumferential direction of the stator. This is advantageous in that the gas film pressure within the second gap 5206 is more uniform.
alternatively, in the third stator 5202 and the fourth stator 5203, the distance from the first static pressure intake orifice 5208 to the axial center of the rotating shaft 100 is greater than or equal to the distance from the first static pressure intake orifice 5208 to the outer peripheral edge of the stator.
In the embodiment of the present invention, the first static pressure intake orifice 5208 is provided in such a manner that the gas static pressure bearing is more stable, and if the static pressure intake orifice is too close to the axis of the rotating shaft 100, the gas film cannot be effectively spread over the entire end surface of the second thrust plate 5201 in time, and the rotation of the second thrust plate 5201 is not stable enough. Preferably, the distance from the first static pressure intake orifice 5208 to the axial center of the rotating 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 slot 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 present invention, by providing the second sensor 5207, a parameter at the second gap 5206, such as an air film pressure at the second gap 5206, can be detected in real time. In this way, the second magnetic bearing 5204 can actively control the thrust bearing 5200 based on the detection result of the second sensor 5207, and can achieve high control accuracy.
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 to the second magnetic bearing 5204, and the second magnetic bearing 5204 is provided with a through hole for the second sensor probe 52072 to pass through; the second end of the second sensor probe 52072 passes through the through hole of 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 close to the second thrust plate 5201.
in the embodiment of the present invention, the second sensor 5207 can be more stably mounted to the second magnetic bearing 5204 by the above-described configuration and mounting manner of the second sensor 5207. Moreover, the second end of the second sensor probe 52072 is flush with the side of the second magnetic bearing 5204 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 disturbance of the air film in the second gap 5206 is avoided.
alternatively, the second sensor 5207 is disposed between the adjacent two fourth magnetic members.
in the embodiment of the present invention, at least one second sensor 5207 should be disposed on each stator, preferably one second sensor 5207 is disposed, and the second sensor 5207 is preferably disposed between two adjacent fourth magnetic members.
optionally, the second sensor 5207 is any one or combination of:
a displacement sensor for detecting the position of the second thrust plate 5201;
A pressure sensor for detecting the pressure of the air film at the second gap 5206;
A speed sensor for detecting the rotational speed of the second thrust plate 5201;
an acceleration sensor for detecting the rotational acceleration of the second thrust plate 5201.
The following describes a specific control method of the embodiment of the present invention when the slot air-magnetic hybrid thrust bearing (in which the fourth magnetic component in the second magnetic bearing is an electromagnet) participates in the control process of the rotor system.
The embodiment of the invention provides a control method of a groove type gas-magnetic hybrid thrust bearing, which comprises the following steps:
And S531, starting a second magnetic bearing in the third stator and the fourth stator, 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 plurality of fourth magnetic components, so that the difference value 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 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 rotor system is stopped, starting a second magnetic bearing in the third stator and the fourth stator.
And S534, after the rotating speed of the rotating shaft is reduced to zero, closing the second magnetic bearing in the third stator and the fourth stator.
In the process, after the second magnetic bearing is started, the second thrust disc reaches a preset position between the third stator and the fourth stator under the action of the second magnetic bearing, and second gaps are formed among the second thrust disc, the third stator and the end face of the fourth stator.
As the rotating shaft rotates, the second thrust plate starts rotating relative to the third stator and the fourth stator while being lubricated by the air flow in the second gap, to prevent wear. The specific process of opening the second magnetic bearing is as follows: and a current signal with a preset value is input into the second coil, and the second thrust disc reaches a preset position between the third stator and the fourth stator under the action of the second magnetic bearing.
With the increasing of the rotating speed of the rotating shaft, the rotating speed of the second thrust disc is synchronously increased, when the rotating speed of the rotating shaft reaches the working rotating speed, the second thrust disc can be stabilized by the air film pressure generated by the aerodynamic pressure bearing of the thrust bearing (the second thrust disc, the third stator and the fourth stator are provided with a second gap to form the aerodynamic pressure bearing of the thrust bearing), and then the second magnetic bearing can be closed.
When the rotor system stops, the second thrust disc decelerates along with the deceleration of the rotating shaft, and in order to keep the rotating shaft stable in the whole rotor system stopping process, the second magnetic bearing is started when the rotor system stops, and the second magnetic bearing is closed until the second thrust disc completely stops.
the embodiment of the invention also provides another control method of the groove type gas-magnetic hybrid thrust bearing, which comprises the following steps:
and S541, starting a second magnetic bearing in the third stator and the fourth stator, 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 plurality of fourth magnetic components, so that the difference value 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 smaller than or equal to a preset value.
And S542, after the rotating speed of the rotating shaft is accelerated to the first preset value, closing the second magnetic bearing in the third stator and the fourth stator.
and S543, when the rotating speed of the rotating shaft is reduced to a second preset value, starting a second magnetic bearing in the third stator and the fourth stator.
And S544, after the rotating speed of the rotating shaft is reduced to zero, closing the second magnetic bearing in the third stator and the fourth stator.
in the process, after the second magnetic bearing is started, the second thrust disc reaches a preset position between the third stator and the fourth stator under the action of the second magnetic bearing, and second gaps are formed among the second thrust disc, the third stator and the end face of the fourth stator. As the rotating shaft rotates, the second thrust plate starts rotating relative to the third stator and the fourth stator while being lubricated by the air flow in the second gap, to prevent wear. The specific process of opening the second magnetic bearing is as follows: and a current signal with a preset value is input into the second coil, and the second thrust disc reaches a preset position between the third stator and the fourth stator under the action of the second magnetic bearing.
As the rotating speed of the rotating shaft is increased, the rotating speed of the second thrust disc is also increased synchronously, and when the rotating speed of the rotating shaft reaches a second preset value, for example, 5% to 30% of the rated rotating speed, the second thrust disc can be stabilized by the air film pressure generated by the aerodynamic bearing of the thrust bearing (the aerodynamic bearing which forms 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 at that time, the second magnetic bearing can be closed.
During the shutdown process of the rotor system, the second thrust disc decelerates 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, at this time, the air film pressure generated by the aerodynamic bearing of the thrust bearing also decreases along with the deceleration of the second thrust disc, so that the second magnetic bearing needs to be opened to keep the second thrust disc stable, and the second magnetic bearing can be closed until the second thrust disc completely stops.
Optionally, the method further includes:
When the load is loaded on a 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 when the difference value 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 less than or equal to a preset value, closing the second magnetic bearing in the third stator or the fourth stator.
When a load is applied to the second thrust disk and the second gap between the second thrust disk and the second magnetic bearing of the third stator or the fourth stator becomes smaller and approaches the second magnetic bearing on the side, the second sensor (here, the second sensor is preferably a pressure sensor) obtains a signal indicating that the air pressure is increased, and the second magnetic bearing needs to be operated. The second magnetic bearing acts magnetic force on the second thrust disc to move the second thrust disc to the second magnetic bearing on the other side, and when the second thrust disc reaches a new balance position, the second magnetic bearing stops working.
Specifically, if a second gap between the second thrust disk and the second magnetic bearing of the third stator is smaller than a second gap between the second thrust disk and the second magnetic bearing of the fourth stator, and a difference between the second gap between the second thrust disk and the second magnetic bearing of the third stator and the second gap between the second thrust disk and the second magnetic bearing of the fourth stator is greater than a predetermined value, the second magnetic bearing of the fourth stator is controlled to move the second thrust disk in the axial direction of the rotating shaft in the direction away from the fourth stator under the magnetic force action between the third magnetic member and the plurality of fourth magnetic members.
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 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 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 away from the third stator under the action of the magnetic force between the third magnetic component and the plurality of fourth magnetic components.
Optionally, when a 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 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, controlling the second magnetic bearing in the third stator or the fourth stator to be started at the maximum power; or,
And 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 greater than a preset value, controlling the second magnetic bearing in the third stator or the fourth stator to be started in a stroboscopic mode according to preset frequency.
When external impact disturbance occurs, the second thrust disc can be quickly close to the second magnetic bearing on one side, so that the second gap on the side is instantaneously too small, the local gas flow velocity at the second gap on the side is close to even reaches the sonic velocity, and the shock wave is caused to generate the air hammer self-excitation phenomenon. The generation of the shock wave causes turbulence and chaos in the local gas flow, with the pressure dropping dramatically in steps as the fluid velocity changes from 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 a stroboscopic manner according to a preset frequency, so as to provide a damping effect on the disturbance, thereby effectively suppressing the external disturbance. And when the second thrust disc returns to the balance state again, the second magnetic bearing stops working.
In the embodiment of the present invention, in the case where the electromagnetic bearing (the fourth magnetic member in the second magnetic bearing is an electromagnet, that is, the electromagnetic bearing is formed) and the aerostatic bearing (the aerostatic bearing is formed by the first static pressure intake orifice provided in the third stator and the fourth stator) are provided at the same time, the electromagnetic bearing and the aerostatic bearing can be mutually backed up, and in the case where one of them fails, or fails to satisfy the opening condition, the other can serve as the backup bearing to perform the same function. For example, in the case of detecting the failure of the electromagnetic bearing, an external air source is controlled to be opened to perform corresponding actions instead of the electromagnetic bearing, so that the safety and the reliability of the bearing are improved.
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 "turning on the hydrostatic bearing in the thrust bearing to move the thrust disk of the thrust bearing to the preset axial position" may include the following embodiments:
Turning on 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 gas inlet throttling hole;
Controlling the second thrust disc to move in an axial direction of the rotating shaft under a magnetic force between the third magnetic member and the fourth magnetic member, and/or a pushing action of the gas, so that a difference between the second gap between the second thrust disc and a second magnetic bearing of the third stator and the second gap between the second thrust disc and a second magnetic bearing of the fourth stator is less than or equal to the predetermined value.
In the process, the second thrust disc is fixed in a certain minimum range in the axial direction of the rotating shaft by utilizing the advantage that the second magnetic bearing is convenient to control in real time and actively balancing the unbalanced mass of the second thrust disc or the factors causing the excessive deviation of the second thrust disc, such as the whirling motion of the second thrust disc. In addition, in the acceleration process of the second thrust disc, the position (namely the linear velocity supersonic speed part) generating the shock wave can be accurately positioned, and the second magnetic bearing generates opposite force to balance the shock wave action by controlling the current magnitude, the current direction and the like of the second magnetic bearing. And after the shock wave is stable, adjusting the control strategy of the second magnetic bearing again, and fixing the second thrust disc in a certain minimum range in a 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 improved. Meanwhile, the electromagnetic bearing and the gas bearing are in a parallel connection 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 rotor system is started or stopped, the electromagnetic bearing can be used for enabling the thrust disc and the stator of the bearing to rotate in the second gap, the low-speed performance of the bearing is improved, the service life of the bearing is prolonged, and the safety and the reliability of the bearing and the whole system can be improved.
Secondly, compared with the traditional gas dynamic and static pressure hybrid thrust bearing adopting the combination of a gas static pressure bearing and a gas dynamic pressure bearing, the groove type gas-magnetic hybrid thrust bearing provided by the embodiment of the invention has the advantage of high response speed.
And thirdly, the gas hydrostatic bearing is added to form a groove type hybrid dynamic-static pressure-magnetic thrust bearing, under the condition that the electromagnetic bearing and the gas hydrostatic bearing are arranged at the same time, the bearing capacity of the bearing is further increased, the electromagnetic bearing and the gas hydrostatic bearing can be mutually standby, and under the condition that one of the two bearings is failed, fails or cannot meet the starting condition, the other bearing can be used as a standby bearing to play the same role. For example, in the case of detecting the failure of the electromagnetic bearing, the control system controls the aerostatic bearing to be opened to replace the electromagnetic bearing to perform corresponding actions, so that the safety and the reliability of the bearing are improved.
Wherein, the gas-magnetic mixing radial bearing can adopt a groove type gas-magnetic mixing radial bearing.
As shown in fig. 37 to 44, 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 arranged on the fourth magnetic bearing 6201 along the circumferential direction;
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, a fourth gap 6203 is provided between the fourth magnetic bearing 6201 and the rotating shaft 100, and the rotating shaft 100 can move in the radial direction of the rotating shaft 100 under the magnetic force of the seventh magnetic components.
in the embodiment of the present invention, the radial bearing 6200 is formed into a gas-magnetic hybrid radial bearing by providing the fourth gap 6203 and the fourth magnetic bearing 6201 in the radial bearing 6200.
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 gas bearing is used for realizing support; and when the radial bearing 6200 is in an unstable working state, the radial bearing 6200 is controlled and responded by the fourth magnetic bearing 6201 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 rotor system with high rotating speed, such as a gas turbine or a gas turbine power generation combined unit.
In the embodiment of the present invention, since the silicon steel sheet or the silicon steel sheet has physical properties such as high magnetic permeability and low eddy current loss, the rotating shaft 100 may be formed by laminating a plurality of silicon steel sheets or silicon steel sheets.
In the embodiment of the present invention, when the rotational shaft 100 rotates, the flowing gas existing in the fourth gap 6203 is pressed into the third dynamic pressure generating groove 6202, thereby generating a pressure to float the rotational shaft 100 to achieve that the rotational shaft 100 is non-contact held in the radial direction. The pressure generated by the third dynamic pressure generating groove 6202 varies with the angle, groove width, groove length, groove depth, number of grooves, and flatness of the third dynamic pressure generating groove 6202. In addition, the magnitude of the pressure generated by the third dynamic pressure generating groove 6202 is also related to the rotation speed of the rotating shaft 100 and the fourth gap 6203. The parameters of the third dynamic pressure generating groove 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.
Optionally, the plurality of seventh magnetic members include a plurality of fourth permanent magnets, which are circumferentially disposed on the fourth magnetic bearing 6201;
Alternatively, the plurality of seventh magnetic members include a plurality of fourth electromagnets disposed circumferentially on the fourth magnetic bearing 6201, and each of the plurality of fourth electromagnets includes a fourth magnetic core 62011 disposed on the fourth magnetic bearing 6201 and a fourth coil 62012 wound on the fourth magnetic core 62011.
in the embodiment of the invention, when the groove type air-magnetic hybrid radial bearing 6200 only needs the magnetic part to provide magnetic force and does not need magnetic control, the seventh magnetic part is preferably a fourth permanent magnet; when the foil gas-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 the 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 of current flow to the fourth coil 62012 is different, and the magnetic pole of the fourth magnetic core 62011 is also different.
In a 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 properties of high magnetic permeability and low eddy current loss.
optionally, the fourth magnetic bearing 6201 includes:
A fourth magnetic bearing holder 62013, in which the fourth magnetic bearing holder 62013 is sleeved on the rotating shaft 100, a plurality of fourth accommodating grooves 62014 are circumferentially disposed on the fourth magnetic bearing holder 62013, a plurality of seventh magnetic members are disposed in the plurality of fourth accommodating grooves 62014, and magnetic poles of the plurality of seventh magnetic members face the rotating shaft 100;
A second bearing housing 62015 sleeved outside the fourth magnetic bearing seat 62013;
A second bearing cover 62016 sleeved between the fourth magnetic bearing pedestal 62013 and the rotating shaft 100;
And a fifth end cap 62017 and a sixth end cap 62018 disposed at both ends of the second bearing shell 62015, respectively;
The second bearing cover 62016, the fifth end cap 62017, and the sixth end cap 62018 cooperate to fix the seventh magnetic components to the fourth magnetic bearing seat 62013.
in the embodiment of the present invention, by providing the second bearing cover 62016, the 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 second bearing sleeves 62016 of different radial thicknesses.
Wherein, the width of the fourth gap 6203 between the second bearing cover 62016 and the rotating shaft 100 may be 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 laminating a plurality of silicon steel sheets or silicon steel sheets, because the silicon steel sheets or silicon steel sheets have physical properties such as high magnetic permeability and low eddy current loss. The number of the fourth receiving grooves 62014 may be, but is not limited to, six or eight, which are uniformly arranged in the circumferential direction of the fourth magnetic bearing base 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 holder 62013 in another manner, which is not limited. The material of fifth end cap 62017 and sixth end cap 62018 may each be a non-magnetic material, preferably a duralumin material. The material of the second bearing cover 62016 may be a non-magnetic material, preferably a duralumin material. The material of the second bearing shell 62015 may be a non-magnetic material, preferably a duralumin material.
preferably, the fifth end cap 62017 and the sixth end cap 62018 are provided with bosses 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 for fixing and pressing silicon steel sheets or silicon steel sheets constituting the fourth magnetic bearing base 62013 from both ends.
In the embodiment of the present invention, the third dynamic pressure generating groove 6202 may be provided on the second bearing sleeve 62016, and in order to facilitate the machining of the third dynamic pressure generating groove 6202, the second bearing sleeve 62016 may be made of a stainless steel material. Specifically, the third dynamic pressure generating grooves 6202 may be provided at a middle portion of the rotating shaft 100 corresponding to the circumferential surface of the second bearing sleeve 62016, or may be provided as two independent third dynamic pressure generating grooves 6202 symmetrically distributed at both sides of the middle portion; the third dynamic pressure generating grooves 6202 may be provided in a middle portion of an inner sidewall of the second bearing sleeve 62016, or may be provided as two independent portions of the third dynamic pressure generating grooves 6202 that are symmetrically distributed at both ends of the inner sidewall of the second bearing sleeve 62016.
Optionally, the third dynamic pressure generating grooves 6202 are arranged in a matrix, which is beneficial to more uniformly distributing the gas film in the fourth gap 6203.
Alternatively, the third dynamic pressure generating grooves 6202 are V-shaped grooves provided continuously or at intervals.
In the embodiment of the present invention, by adopting the above-described arrangement manner of the third dynamic pressure generating groove 6202, the rotating shaft 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 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 grooves 6202 may be provided as chevron-shaped grooves or grooves of other shapes, in addition to the V-shaped grooves.
Optionally, a second static pressure intake orifice 6205 is also disposed on the fourth magnetic bearing 6201, one end of the second static pressure intake orifice 6205 is communicated with the fourth gap 6203, and the other end is connected to an external air source for delivering the external air source into the fourth gap 6203.
In the embodiment of the present invention, by providing the second static pressure intake orifice 6205, a gas static pressure bearing may be formed, so that the groove type gas-magnetic hybrid radial bearing 6200 may constitute a groove type gas static pressure-magnetic hybrid radial bearing. The flow diameter of the second static pressure air inlet throttle 6205 can be adjusted according to actual working conditions such as air quantity requirements and the like.
Optionally, the second static inlet orifice 6205 branches within the fourth magnetic bearing 6201 into a fourth gap 6203.
In embodiments of the present invention, the second static inlet orifice 6205 may, in turn, pass through the fifth end cover 62017 or the sixth end cover 62018, the fourth magnetic bearing 6201, and the second bearing housing 62016 to communicate an external gas source to the fourth gap 6203. Further, the second static pressure intake orifice 6205 may branch into two or more branches to the fourth gap 6203, so that the film pressure in the fourth gap 6203 is more uniform. Further, an annular groove may be provided in the fifth end cover 62017 or the sixth end cover 62018, and a plurality of second static pressure 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 intake orifice 6205 may be provided in each fourth magnetic core 62011 or in each two adjacent fourth magnetic cores 62011. The flow diameters of the second static pressure intake orifice 6205 and the branch can be adjusted according to actual working conditions such as air quantity requirements.
Optionally, the slot-type gas-magnetic hybrid radial bearing 6200 further comprises a plurality of fourth sensors 6204 disposed circumferentially spaced apart along the fourth magnetic bearing 6201, wherein the 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, a pressure of an air film 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 based on the detection result of the fourth sensor 6204, and can achieve high accuracy in control.
optionally, each of the fourth sensors 6204 includes a fourth sensor cover 62041 and a fourth sensor probe 62042, the first end of the fourth sensor probe 62042 is connected to the fourth sensor cover 62041, the fourth sensor cover 62041 is fixed to the fourth magnetic bearing 6201, and a through hole for the fourth sensor probe 62042 to pass through is formed in the fourth magnetic bearing 6201; the second end of the fourth sensor probe 62042 passes through the through hole of 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 close to the rotating shaft 100.
In the embodiment of the present invention, the fourth sensor 6204 can be more stably mounted 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 of the fourth magnetic bearing 6201 close to the rotating shaft 100, so that 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 the fourth sensors 6204 may be the same as the number of the seventh magnetic members. The fourth sensor 6204 may be disposed between two adjacent seventh magnetic components, or may be disposed through the seventh magnetic components, which is not limited in the embodiment of the present invention. Each fourth sensor 6204 is preferably disposed in a middle portion of the fourth magnetic bearing 6201.
Optionally, the plurality of fourth sensors 6204 is any one or more of the following in combination:
a displacement sensor for detecting the position of the rotating shaft 100;
A pressure sensor for detecting the air film pressure at the fourth gap 6203;
A speed sensor for detecting a rotation speed of the rotary shaft 100;
an acceleration sensor for detecting the rotational acceleration of the rotary shaft 100.
The following describes a specific control method of the embodiment of the present invention when the slot air-magnetic hybrid radial bearing (in which the seventh magnetic component in the fourth magnetic bearing is an electromagnet) participates in the control process of the rotor system.
The embodiment of the invention provides a control method of a groove type gas-magnetic mixed radial bearing, which comprises the following steps:
and S631, starting the fourth magnetic bearing, controlling the rotating shaft to move in the radial direction of the rotating shaft under the magnetic force action of the seventh magnetic components, and pushing the rotating shaft to a preset radial position.
And S632, after the rotating speed of the rotating shaft is accelerated to the working rotating speed, closing the fourth magnetic bearing.
and S633, starting the fourth magnetic bearing when the rotor system is stopped.
And S634, after the rotating speed of the rotating shaft is reduced to zero, closing the fourth magnetic bearing.
In the process, after the fourth magnetic bearing is started, 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.
as the rotating shaft rotates, the rotating shaft starts rotating while being lubricated by the air flow in the fourth gap to prevent wear. The specific process of opening the fourth magnetic bearing is as follows: and a current signal with a preset value is input into the fourth coil, and the rotating shaft is supported under the action of the fourth magnetic bearing and reaches 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 rotating shaft can be stabilized by the air film pressure generated by the aerodynamic bearing of the radial bearing (the fourth gap is arranged between the fourth magnetic bearing and the rotating shaft, namely the aerodynamic bearing of the radial bearing is formed), and then the fourth magnetic bearing can be closed.
when the rotor system stops, the rotating shaft decelerates, and in order to keep the rotating shaft stable in the whole rotor system stopping process, the fourth magnetic bearing is started when the rotor system stops, and the fourth magnetic bearing is closed until the rotating shaft completely stops.
the embodiment of the invention also provides another control method of the slot type gas-magnetic mixed radial bearing, which comprises the following steps:
and S641, starting the fourth magnetic bearing, controlling the rotating shaft to move in the radial direction of the rotating shaft under the magnetic force action 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 rotation 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 in 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 returns to the equilibrium radial position.
Optionally, when the rotation speed of the rotating shaft is accelerated to the first-order critical speed or the second-order critical speed, the fourth magnetic bearing is turned on, 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 a first-order critical speed or a second-order critical speed, the fourth magnetic bearing is controlled to be started in a stroboscopic mode according to the preset frequency.
And S644, after the rotor system passes the first-order critical speed or the second-order critical speed, the fourth magnetic bearing is closed.
And S645, in the process of stopping the rotor system, when the rotor system decelerates to a first-order critical speed or a second-order critical speed, the fourth magnetic bearing is started.
Specifically, when the gas flow velocity in the fourth gap between the rotating shaft and the fourth magnetic bearing is reduced to the first-order critical velocity or the second-order critical velocity, the fourth magnetic bearing is turned on until the rotating shaft is restored to the equilibrium radial position.
Optionally, when the rotation speed of the rotating shaft is reduced to the first-order critical speed or the second-order critical speed, the fourth magnetic bearing is turned on, 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 a first-order critical speed or a second-order critical speed, the fourth magnetic bearing is controlled to be started in a stroboscopic mode according to the preset frequency.
and S646, after the rotor system passes through the first-order critical speed or the second-order critical speed in a smooth mode, closing the fourth magnetic bearing.
And S647, when the rotating speed of the rotating shaft is reduced to a second preset value, starting the fourth magnetic bearing.
and S648, closing the fourth magnetic bearing after the rotating speed of the rotating shaft is reduced to zero.
In the process, after the fourth magnetic bearing is started, 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.
As the rotating shaft rotates, the rotating shaft starts rotating while being lubricated by the air flow in the fourth gap to prevent wear. The specific process of opening the fourth magnetic bearing is as follows: and a current signal with a preset value is input into the fourth coil, and the rotating shaft is supported under the action of the fourth magnetic bearing and reaches a preset radial position.
As the rotating speed of the rotating shaft is increased, when the rotating speed of the rotating shaft reaches a first preset value, for example, 5% to 30% of the rated rotating speed, the rotating shaft can be stabilized by the air film pressure generated by the aerodynamic bearing of the radial bearing (the aerodynamic bearing forming the radial bearing is provided with a fourth gap between the fourth magnetic bearing and the rotating shaft), and then the fourth magnetic bearing can be closed.
During the shutdown process of the rotor system, 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 until the rotating shaft is completely stopped, and then the fourth magnetic bearing is closed.
Optionally, the method further includes:
When a fourth gap between the rotating shaft and the fourth magnetic bearing is changed, the fourth magnetic bearing is started, and the rotating shaft moves towards a direction away from the gap reducing side under the action of the magnetic force of the seventh magnetic components;
the fourth magnetic bearing is turned off after the shaft is in an equilibrium radial position.
When a load is loaded on the rotating shaft, so that the rotating shaft gradually descends and approaches the lower fourth magnetic bearing, the fourth sensor (preferably a pressure sensor) obtains a signal of air pressure increase, and the fourth magnetic bearing needs to be operated in an intervening mode. The fourth magnetic bearing acts magnetic force on the rotating shaft to enable the rotating shaft to be suspended 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 can be fast close to the fourth magnetic bearing, which may cause the gap between the rotating shaft and the fourth magnetic bearing to be instantaneously too small, so that the local gas flow velocity at the gap reduction position is close to or even reaches the sonic velocity, thereby causing the shock wave to generate the self-excitation phenomenon of the air hammer. The generation of the shock wave causes turbulence and chaos in the local gas flow, with the pressure dropping dramatically in steps as the fluid velocity changes from sonic to subsonic. In this case, the seventh magnetic component of the fourth magnetic bearing needs to be controlled to be turned on in turn at a preset frequency to provide a damping effect on the disturbance, so as to effectively suppress the external disturbance. The fourth magnetic bearing ceases operation after the shaft has returned to the new equilibrium radial position.
In the embodiment of the present invention, in the case where the electromagnetic bearing (the seventh magnetic member in the fourth magnetic bearing is an electromagnet, that is, the electromagnetic bearing is formed) and the aerostatic bearing (the aerostatic bearing is formed as the second static pressure intake orifice provided in the fourth magnetic bearing) are provided at the same time, the electromagnetic bearing and the aerostatic bearing may be mutually backup, and in the case where one of them fails, or fails to satisfy the opening condition, the other may serve as a backup bearing to perform the same function. For example, in the case of detecting the failure of the electromagnetic bearing, an external air source is controlled to be opened to perform corresponding actions instead of the electromagnetic bearing, so that the safety and the reliability of the bearing are improved.
in the embodiment of the present invention, in the case that the electromagnetic bearing and the aerostatic bearing are provided at the same time, the step of "turning on the hydrostatic bearing in the radial bearing to move the rotating shaft to the preset radial position" may include the following embodiments:
Turning on the fourth magnetic bearing; and/or starting an external gas source, and conveying gas to the fourth gap through the second static pressure gas inlet throttling hole;
And controlling the rotating shaft to move in the radial direction of the rotating shaft under the magnetic force action 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 fourth magnetic bearing is utilized to facilitate the real-time control, and the unbalanced mass of the rotating shaft or the factors of excessive deviation of the rotating shaft caused by the whirling motion 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 position) where the shock wave is generated can be accurately positioned, and the shock wave action is balanced by controlling the current magnitude, the current direction and the like of the fourth magnetic bearing to enable the fourth magnetic bearing to generate opposite force. And after the shock wave is stable, adjusting the control strategy of the fourth magnetic bearing again, and fixing the rotating shaft in a certain minimum range in a 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 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 rotor system is started or stopped, the electromagnetic bearing can be used for enabling the thrust disc and the stator of the bearing to rotate in the first gap, the low-speed performance of the bearing is improved, the service life of the bearing is prolonged, and the safety and the reliability of the bearing and the whole system can be improved.
Secondly, compared with the traditional gas dynamic and static pressure mixed thrust bearing adopting the combination of a gas static pressure bearing and a gas dynamic pressure bearing, the groove type gas-magnetic mixed radial bearing provided by the embodiment of the invention has the advantage of high response speed.
And thirdly, the gas hydrostatic bearing is added to form a groove type hybrid dynamic-static pressure-magnetic thrust bearing, under the condition that the electromagnetic bearing and the gas hydrostatic bearing are arranged at the same time, the bearing capacity of the bearing is further increased, the electromagnetic bearing and the gas hydrostatic bearing can be mutually standby, and under the condition that one of the two bearings is failed, fails or cannot meet the starting condition, the other bearing can be used as a standby bearing to play the same role. For example, in the case of detecting the failure of the electromagnetic bearing, the control system controls the aerostatic bearing to be opened to replace the electromagnetic bearing to perform corresponding actions, so that the safety and the reliability of the bearing are improved.
The above description is only for the specific 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 conceive of the changes or substitutions within the technical scope of the present invention, and the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.