CN111042921B

CN111042921B - Multistage turbine type micro gas turbine

Info

Publication number: CN111042921B
Application number: CN201911370983.7A
Authority: CN
Inventors: 靳普; 于宁
Original assignee: Beijing Yongxu Tengfeng New Energy Power Technology Development Co ltd; Zhiyue Tengfeng Technology Group Co ltd
Current assignee: Beijing Yongxu Tengfeng New Energy Power Technology Development Co ltd; Zhiyue Tengfeng Technology Group Co ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2024-07-16
Anticipated expiration: 2039-12-27
Also published as: CN111042921A

Abstract

The invention provides a multistage turbine type miniature gas turbine, which comprises a high-pressure machine and a low-pressure machine; the high-pressure machine comprises a high-pressure casing, a gas compressor, a high-pressure turbine set, a combustion chamber, a high-pressure rotor system and a starting motor, wherein the low-pressure machine comprises a low-pressure casing, a low-pressure turbine set, a generator, a low-pressure rotor system and a flue gas chamber, the gas inlet end of the gas compressor is communicated with the outside, the gas outlet end of the gas compressor is communicated with the inlet end of the combustion chamber, the outlet end of the combustion chamber is communicated with the gas inlet end of the high-pressure turbine set, the gas outlet end of the high-pressure turbine set is communicated with the gas inlet end of the low-pressure turbine set, the gas outlet end of the low-pressure turbine set is communicated with the inlet of the flue gas chamber, and the outlet of the flue gas chamber is communicated with the outside. The high-pressure turbine and the low-speed turbine are arranged in multiple stages, so that the multi-row turbine-stage micro gas turbine is formed, the structural layout is reasonable, the operation is stable, and the efficiency is high.

Description

Multistage turbine type micro gas turbine

Technical Field

The invention relates to the field of gas turbines, in particular to a multistage turbine type micro gas turbine.

Background

Micro gas turbines are a newly developed type of small heat engine, and the single machine power range is 25-300 kW, and the basic technical characteristics are that radial flow impeller machinery and regenerative cycle are adopted. The miniature gas turbine motor group in the prior art has the following defects:

The general structure employed by current micro gas turbines includes single rotors and multiple rotors. The single rotor structure is provided with only one shaft, the compressor and the turbine are all arranged on the shaft, and the structure is simple and the economy is good. Theoretically, the compressor of the micro gas turbine with a single rotor structure can be made into any number of stages to achieve a certain supercharging ratio. However, the structural limitation of the single rotor makes all parts mounted on the same main shaft, when the rotation speed of the single rotor suddenly drops, the efficiency of the high-pressure part of the compressor is seriously reduced because the sufficient rotation speed is not obtained, and meanwhile, the load of the low-pressure part of the compressor is sharply increased. Surging may occur when the low pressure compressor is partially overloaded, which is not allowed during normal operation. To solve this problem, it is common to add guide vanes before the compressor or to bleed air at an intermediate stage of the compressor, i.e. to empty a portion of the pressurized air to reduce the load on the low pressure portion of the compressor. The disadvantage of this approach is evident, not only in that it greatly reduces the efficiency, but also in that it does not have a very pronounced effect on the compressor with high boost ratio.

In order to improve the working efficiency of the compressor and reduce surge, multiple rotors have been conceived to solve the problem. For example, operating the low pressure compressor and the high pressure compressor of a micro gas turbine at different rotational speeds. The low-pressure compressor and the low-pressure turbine are linked to form a low-pressure rotor, and the high-pressure compressor and the high-pressure turbine are linked to form a high-pressure rotor. The rotational speed of the low pressure rotor is relatively low. Because of the compression, the air temperature in the compressor increases, and because the sound velocity also increases with the increase in air temperature, the upper rotational speed limit of the high-pressure rotor can be increased, and the diameter of the high-pressure rotor can be reduced. Because the high-pressure rotor of the double-rotor miniature gas turbine has lighter weight and small starting inertia, the double-rotor miniature gas turbine can be driven by a starting motor, compared with a single-rotor structure, the double-rotor miniature gas turbine has easier starting, smaller starting energy and correspondingly reduced weight of starting equipment.

However, in the micro gas turbine with the dual rotor structure, since the fan is linked with the low pressure compressor, the centrifugal force and the tip speed born by the fan with relatively large diameter are also large, the huge centrifugal force requires that the weight of the fan cannot be too large, the length of the blades cannot be too long, the bypass ratio is limited to be improved, and the practice proves that the higher the bypass ratio is, the larger the thrust is, and the oil is relatively saved. The low-pressure compressor also has to reduce the number of revolutions in order to be coupled with the fan, the single-stage supercharging ratio is reduced, and the number of stages of the compressor fan has to be increased in order to achieve the overall supercharging ratio. So that the weight of the compressor is hardly reduced.

In summary, conventional mechanical single rotors have a number of functional limitations, while conventional multi-rotor systems have significant engineering complexity and uncertainty.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a multistage turbine type micro gas turbine.

The technical scheme of the invention is as follows:

A multistage turbine type micro gas turbine comprises a high-pressure machine and a low-pressure machine;

The high-pressure engine comprises a high-pressure casing, a gas compressor, a high-pressure turbine set, a combustion chamber, a high-pressure rotor system and a starting motor, wherein the gas compressor, the high-pressure turbine set and the high-pressure rotor system are arranged in the high-pressure casing, the high-pressure casing is sleeved at one end of the combustion chamber, the gas compressor and the high-pressure turbine set are sequentially and coaxially arranged on the high-pressure rotor system, and the starting motor is arranged at the end, far away from the high-pressure turbine, of the gas compressor;

The low-pressure machine comprises a low-pressure casing, a low-pressure turbine set, a generator, a low-pressure rotor system and a flue gas chamber, wherein the low-pressure turbine set, the generator and the low-pressure rotor system are arranged in the low-pressure casing, and the low-pressure turbine set and the generator are sequentially and coaxially arranged on the low-pressure rotor system;

The air inlet end of the air compressor is communicated with the outside, the air outlet end of the air compressor is communicated with the inlet end of the combustion chamber, the outlet end of the combustion chamber is communicated with the air inlet end of the high-pressure turbine group, the air outlet end of the high-pressure turbine group is communicated with the air inlet end of the low-pressure turbine group, the air outlet end of the low-pressure turbine group is communicated with the inlet of the flue gas chamber, and the outlet of the flue gas chamber is communicated with the outside.

Further, the high-pressure rotor system comprises a first rotating shaft and a high-pressure bearing group;

Wherein the first rotating shaft is of an integrated structure;

The starting motor is sleeved on the first rotating shaft and comprises a motor body and radial bearings arranged at two ends of the motor body, and the radial bearings are arranged between the motor body and the first rotating shaft.

Further, the high-pressure rotor system comprises a first rotating shaft and a bearing;

The first rotating shaft is of a split structure and comprises a high-voltage motor shaft and a high-voltage turbine shaft, and the high-voltage motor shaft and the high-voltage turbine shaft are connected through a coupling;

the starting motor comprises a motor body and radial bearings arranged at two ends of the motor body, wherein the radial bearings are arranged between the motor body and the motor shaft.

Further, the high-pressure turbine group comprises a centripetal turbine and at least one axial turbine, or only comprises more than two axial turbines;

When the centrifugal compressor comprises a centrifugal turbine, the centrifugal turbine and the air compressor are coaxially and fixedly arranged on the high-pressure rotor system in a back-to-back way, the falling pressure ratio of the centrifugal turbine is smaller than 3, and the small end of the centrifugal turbine is adjacently provided with an axial flow turbine.

Further, guide vanes coaxial with the high-pressure turbine group are oppositely arranged at positions between adjacent high-pressure turbines in the high-pressure casing.

Further, the low pressure turbine group includes a centrifugal turbine and at least one axial turbine, or a centripetal turbine and at least one axial turbine, or only two or more axial turbines;

When the centrifugal turbine is included, the small end of the centrifugal turbine is arranged adjacent to the high-pressure machine end, and the large end of the centrifugal turbine is arranged adjacent to the axial flow turbine;

When the centrifugal turbine is included, the large end of the centrifugal turbine is arranged adjacent to the high-pressure machine end, and the small end of the centrifugal turbine is arranged adjacent to the axial flow turbine.

Further, guide vanes coaxial with the low-pressure turbine group are oppositely arranged at positions between adjacent low-pressure turbines in the low-pressure box.

Furthermore, the combustion chamber is a rotary backflow combustion chamber or an axial flow combustion chamber, the axis of the combustion chamber is coaxial with the mounting shafts of the compressor and the high-pressure turbine set, and the combustion chamber is arranged at one side of the high-pressure turbine set far away from the compressor, or the combustion chamber is arranged between the high-pressure turbine set and the compressor.

Further, a plurality of air inlets which axially penetrate through the motor stator are arranged on the motor stator of the starting motor;

Wherein, the motor stator comprises a stator iron core and a stator winding;

The stator core is cylindrical, and a through hole for installing the rotating shaft is formed in the center of the cylinder;

The stator core comprises a stator core body, wherein the outer diameter side of the stator core body is provided with a plurality of outer wire grooves which extend along the axial direction of a cylinder and are uniformly distributed along the circumferential direction of the cylinder, and the inner diameter side of the stator core body is provided with a plurality of inner wire grooves which extend along the axial direction of the cylinder and are uniformly distributed along the circumferential direction of the cylinder;

the stator winding is wound in the outer wire groove and the inner wire groove along the axial direction of the cylinder, and the air inlet channel is formed in the inner wire groove.

Further, the device also comprises a regenerator;

The heat regenerator is provided with a first inlet, a first outlet, a second inlet and a second outlet;

The exhaust end of the compressor is communicated with the first inlet of the heat regenerator, the first outlet of the heat regenerator is communicated with the inlet of the combustion chamber, the exhaust end of the combustion chamber is communicated with the air inlet end of the high-pressure turbine group, the exhaust end of the high-pressure turbine group is communicated with the air inlet end of the low-pressure turbine group, the exhaust end of the low-pressure turbine group is communicated with the inlet of the flue gas chamber, the outlet of the flue gas chamber is communicated with the second inlet of the heat regenerator, and the second outlet of the heat regenerator is communicated with the outside.

Further, the heat regenerator is also provided with a third inlet and a third outlet;

The exhaust end of the high-pressure turbine group is also communicated with a third inlet of the heat regenerator, and a third outlet of the heat regenerator is communicated with the air inlet end of the low-pressure turbine group.

Further, the heat regenerator is arranged outside the combustion chamber in a surrounding way;

The heat regenerator is an annular or square box body;

the heat regenerators are arranged in an integrated or split mode, and when the heat regenerators are arranged in a split mode, the heat regenerators are uniformly or non-uniformly arranged in a plurality of modes;

The first inlet, the second outlet and the third outlet of the heat regenerator are cold ends, the first outlet, the second inlet and the third inlet are hot ends, wherein the first inlet and the first outlet form a first channel, the second inlet and the second outlet form a second channel, the third inlet and the third outlet form a third channel, and the first channel, the second channel and the third channel are not communicated.

Further, the low-pressure rotor system comprises a second rotating shaft and a low-pressure bearing group;

The second rotating shaft comprises a low-pressure turbine shaft and a low-pressure motor shaft, the low-pressure turbine shaft and the low-pressure motor shaft are connected through a coupling, the low-pressure turbine group is arranged on the low-pressure turbine shaft, and the generator is arranged on the low-pressure motor shaft;

The low-pressure turbine group comprises a centrifugal/centripetal turbine and an axial turbine, a first bearing is arranged between the centrifugal/centripetal turbine and the axial turbine, a second bearing and a third bearing are arranged between the low-pressure turbine group and the coupling, and the shaft of the low-pressure turbine is rotationally connected with the motor body through a fourth bearing and a fifth bearing.

Further, the low-pressure casing comprises a first casing and a second casing, the first casing is connected with the second casing through a coupling, wherein the first bearing, the second bearing, the third bearing and the low-pressure turbine set are arranged in the first casing, and the generator, the fourth bearing and the fifth bearing are arranged in the second casing.

Further, the first bearing, the second bearing, the third bearing, the fourth bearing and the fifth bearing are respectively a first radial bearing, a thrust bearing, a second radial bearing, a third radial bearing and a fourth radial bearing;

The first radial bearing is arranged between the centrifugal/centripetal turbine and the axial turbine, the thrust bearing and the second radial bearing are arranged between the low-pressure turbine set and the generator, the thrust bearing is close to the low-pressure turbine set, the second radial bearing is close to the coupler, and the generator is rotatably arranged between the third radial bearing and the fourth radial bearing.

Furthermore, the first radial bearing, the thrust bearing and the second radial bearing are all non-contact bearings, and the third radial bearing and the fourth radial bearing are all non-contact bearings or contact bearings.

Furthermore, the thrust bearing adopts an air-magnetic hybrid thrust bearing or an air thrust bearing or a magnetic bearing, the first radial bearing and the second radial bearing adopt an air-dynamic-static hybrid radial bearing or an air-magnetic hybrid radial bearing, and the third radial bearing and the fourth radial bearing adopt an air-dynamic-static hybrid radial bearing or an air-magnetic hybrid radial bearing or a ball bearing.

Further, the thrust bearing and the second radial bearing are arranged as an integral bearing;

The integrated bearing includes:

The thrust disc is fixedly connected with the turbine shaft or integrally formed;

The first bearing body and the second bearing body are sleeved on the turbine shaft and positioned at two sides of the thrust disc;

Wherein the first bearing body has a radial bearing portion and a thrust bearing portion integrally formed, the radial bearing portion having a predetermined radial clearance in a radial direction with a turbine shaft to form the second radial bearing;

the thrust bearing portion is mounted axially opposite the thrust disk with a predetermined first axial clearance, and the second bearing body is mounted axially opposite the thrust disk with a predetermined second axial clearance, thereby forming the thrust bearing.

wherein the second rotating shaft is an integrated rotating shaft;

The low-pressure turbine set comprises a centrifugal turbine, a centripetal turbine and an axial turbine, a first bearing is arranged between the centrifugal turbine and the centripetal turbine, a second bearing and a third bearing are arranged between the low-pressure turbine set and the generator, and a fourth bearing is arranged on one side, far away from the low-pressure turbine set, of the generator.

Further, the first bearing, the second bearing, the third bearing and the fourth bearing are respectively a first radial bearing, a second radial bearing, a thrust bearing and a third radial bearing;

The first radial bearing is arranged between the centrifugal/centripetal turbine and the axial turbine, the second radial bearing and the thrust bearing are arranged between the low-pressure turbine set and the generator, the second radial bearing is close to the low-pressure turbine set, the thrust bearing is close to the generator, and the third radial bearing is arranged at one end of the generator, which is far away from the low-pressure turbine set.

Further, the first radial bearing, the second radial bearing and the thrust bearing are all non-contact bearings, and the third radial bearing is a non-contact bearing or a contact bearing.

Furthermore, the thrust bearing adopts an air-magnetic hybrid thrust bearing or an air thrust bearing or a magnetic bearing, the first radial bearing and the second radial bearing adopt an air-dynamic-static hybrid radial bearing or an air-magnetic hybrid radial bearing, and the third radial bearing adopts an air-dynamic-static hybrid radial bearing or an air-magnetic hybrid radial bearing or a ball bearing.

Compared with the prior art, the invention has the following beneficial effects:

1. The high-pressure turbine and the low-pressure turbine are arranged in multiple stages to form the multi-row turbine-stage micro gas turbine, and the invention has reasonable structural layout, stable operation and high efficiency.

2. The low-pressure turbine end of the invention has longer bearing span, the cantilever length has smaller proportion relative to the bearing span, and the cantilever can bear stronger force, so a plurality of centripetal turbines and axial-flow turbines can be arranged on the cantilever.

3. According to the invention, by arranging a plurality of turbines to form the turbine group, the centripetal turbines and the axial-flow turbines do work in a grading manner, so that the drop pressure ratio of the single-stage centripetal turbines can be reduced, and the overall efficiency is improved; meanwhile, the axial flow turbine is one-stage or multi-stage, the power generation efficiency of the axial flow turbine is higher than that of the centripetal turbine, and the weight of the axial flow turbine is far lighter than that of the centripetal turbine, so that the gravity center distribution on the cantilever is biased to the front centripetal turbine and the supporting bearing part, and the weight distribution is more reasonable.

4. The enthalpy drop of the inlet gas at the low-pressure turbine end is large, the flow velocity is high, the outlet velocity of each turbine stage is large, and a plurality of stages of guide impellers and axial flow impellers can be arranged behind a single-stage turbine stage (one-stage turbine stage), so that a plurality of rows of stages are formed, and the functional capacity is improved.

Drawings

FIG. 1 is an overall block diagram of a multistage low pressure turbine micro gas turbine in accordance with an embodiment of the present invention.

Fig. 2 is a schematic view of a low-pressure machine according to a first embodiment of the present invention.

Fig. 3 is a schematic view of a high-pressure frame according to a first embodiment of the present invention.

Fig. 4 is a schematic view of a low-pressure frame according to a first embodiment of the invention.

Fig. 5 is a schematic view of another low-pressure machine frame according to the first embodiment of the present invention.

Fig. 6 is a diagram showing a structure of a motor according to a first embodiment of the present invention.

Fig. 7 is a half cross-sectional view of a motor according to a first embodiment of the present invention.

Fig. 8 is a structural diagram of a motor stator core according to a first embodiment of the present invention.

Fig. 9 is a structural view of a silicon steel sheet according to the first embodiment of the present invention.

Fig. 10 is a diagram of an end face slot according to a first embodiment of the present invention.

Fig. 11 is a structural diagram of a regenerator according to a second embodiment of the present invention.

Fig. 12 is a schematic diagram of a rotor system frame according to a third embodiment of the present invention.

Fig. 13 is a structural diagram of an integrated gas bearing according to a third embodiment of the present invention.

Fig. 14 is a front view of a first bearing body according to a third embodiment of the present invention.

Fig. 15 is a left side view of a first bearing body according to a third embodiment of the present invention.

Fig. 16 is a schematic diagram of a rotor system frame according to a fourth embodiment of the present invention.

Detailed Description

For a better understanding of the technical solution of the present invention, the present invention will be further described with reference to the following specific examples and the accompanying drawings.

Example 1

As shown in fig. 1-5, the present embodiment provides a multi-stage turbine micro gas turbine, which has a high-pressure engine 1 and a low-pressure engine 2, wherein the high-pressure engine 1 includes a high-pressure casing, a gas compressor 11, a high-pressure turbine set 12, a combustion chamber 13, a high-pressure bearing set 15, a first rotating shaft 14, and a starting motor 16, and the low-pressure engine 2 includes a low-pressure casing, a low-pressure turbine set 21, a generator 22, a low-pressure bearing set 24, and a second rotating shaft 23; the compressor 11, the high-pressure turbine group 12, the high-pressure bearing group 15 and the first rotating shaft 14 are arranged in a high-pressure casing, the high-pressure casing is sleeved at one end of the combustion chamber 13, the compressor 11 and the high-pressure turbine group 12 are sequentially sleeved on the first rotating shaft 14, and a starting motor 16 is arranged at the end, far away from the high-pressure turbine group 12, of the compressor 11; the low-pressure turbine group 21, the generator 22, the low-pressure bearing group 24 and the second rotating shaft 23 are arranged in the low-pressure casing, and the low-pressure turbine group 21 and the generator 22 are sequentially and coaxially and fixedly arranged on the second rotating shaft 23.

The air inlet end of the air compressor 11 is communicated with the outside, the air outlet end of the air compressor 11 is communicated with the inlet end of the combustion chamber 13, the outlet end of the combustion chamber 13 is communicated with the air inlet end of the high-pressure turbine set 12, the air outlet end of the high-pressure turbine set 12 is communicated with the air inlet end of the low-pressure turbine set 21, the flue gas chamber 25 is arranged on one side of the low-pressure turbine set 21, the inlet of the flue gas chamber 25 is communicated with the air outlet end of the low-pressure turbine set 21, and the outlet of the flue gas chamber 25 is communicated with the outside. The high-temperature and high-pressure gas discharged from the exhaust end of the high-pressure machine 1 enters the air inlet end of the low-pressure turbine set 21 to push the low-pressure turbine set 21 to rotate, so as to drive the generator 22 to generate electricity, and the low-pressure turbine set 21 and the high-pressure turbine set 12 are arranged in a same-direction and non-connection mode.

Preferably, the first rotating shaft 14 is in an integrated structure, the starting motor 16 is sleeved on the first rotating shaft 14, the starting motor 16 comprises a motor body and radial bearings arranged at two ends of the motor body, and the radial bearings are arranged between the motor body and the first rotating shaft 14.

Preferably, the first rotating shaft 14 is of a split structure, and comprises a high-voltage motor shaft and a high-voltage turbine shaft, the high-voltage motor shaft and the high-voltage turbine rotating shaft are connected through a coupling, the starting motor 16 comprises a motor body and radial bearings arranged at two ends of the motor body, and the radial bearings are arranged between the motor body and the motor shaft.

Preferably, the high-pressure turbine group 12 comprises a centripetal turbine and at least one axial turbine, or only more than two axial turbines,

When the centrifugal compressor comprises a centrifugal turbine, the centrifugal turbine and the compressor 11 are coaxially and fixedly arranged on the first rotating shaft 14 in a way of being away from the large end, the drop pressure ratio of the centrifugal turbine is smaller than 3, and the small end of the centrifugal turbine is adjacently provided with an axial flow turbine.

Preferably, guide vanes coaxial with the high-pressure turbine group 12 are arranged in the high-pressure casing at positions relative to adjacent turbines, heat conduction can be achieved through the high-pressure casing, heat is transferred to the energy recovery device, and the temperature of gas before the compressor can be increased, so that the power and the thermal efficiency of the gas turbine are improved.

Further, the low pressure turbine group 21 includes a centrifugal turbine 211 and at least one axial turbine 212, or a centripetal turbine and at least one axial turbine 212, or only includes two or more axial turbines 212;

when the centrifugal turbine 211 is included, the small end of the centrifugal turbine 211 is arranged adjacent to the high-pressure machine 1 end, and the large end of the centrifugal turbine 211 is arranged adjacent to the axial flow turbine 212;

when included, the large end of the centripetal turbine is disposed adjacent to the high-pressure machine 1 end and the small end of the centripetal turbine is disposed adjacent to the axial turbine 212.

Preferably, the guide vanes coaxial with the low-pressure turbine group 21 are arranged at positions in the low-pressure box relative to adjacent turbines, heat conduction can be realized through the low-pressure box, heat is transferred to the energy recovery device, and the power and the heat efficiency of the gas turbine can be improved.

Preferably, the combustion chamber 13 is a revolving backflow combustion chamber or an axial flow combustion chamber, the axis of the combustion chamber 13 is coaxial with the mounting shafts of the compressor 11 and the high-pressure turbine set 12, the combustion chamber 13 is arranged on one side of the turbine far away from the compressor 11, or the combustion chamber 13 is arranged between the turbine and the compressor 11, and high-temperature and high-pressure gas generated by mixing combustion of the combustion chamber 13 and fuel expands in the high-pressure turbine set to do work.

Preferably, the flue gas chamber 25 is disposed at the other side of the low pressure turbine group 21, and the outlet of the flue gas chamber 25 is square or other shape.

Preferably, an AC-DC module is connected to the generator 22, the generator 22 being arranged for passive or active rectification.

Preferably, the starter motor 16 is formed with air inlet channels in its motor stator by back winding. Specific:

As shown in fig. 6, the starter motor 16 includes: the motor stator 410 and the motor housing 430, wherein the motor stator 410 is sleeved on the first rotating shaft 14, a certain gap is kept between the motor stator 410 and the first rotating shaft 14 in the radial direction, the motor housing 430 is covered on the periphery of the motor stator 410, and a plurality of air inlets 440 axially penetrating through the motor stator 410 are arranged on the motor stator 410.

Due to the arrangement of the air inlet channel 440, when the motor is used in a rotor system and a gas turbine generator set, air inlet of the air compressor 11 can enter the air compressor 11 through the air inlet channel 440, so that air inlet of the air compressor 11 is more sufficient, and meanwhile, normal-temperature air passing through the air inlet channel 440 can play a certain role in cooling the motor stator 410.

Specifically, the formation of the air intake duct 440 described above may be achieved by the following structure and winding manner. Referring to fig. 7, a motor is shown in semi-section; and fig. 8, a structural view of the motor stator core 411.

The motor stator 410 includes a stator core 411 and a stator winding 412, the stator core 411 is in a cylindrical shape, and a through hole 4111 for mounting the first rotating shaft 14 is formed at a central position of the cylinder; the outer diameter side of the stator core 411 is formed with a plurality of first winding spacers 4112 extending along the axial direction and the radial direction of the cylinder and uniformly distributed along the circumferential direction of the cylinder, the inner diameter side of the stator core 411 is formed with a plurality of second winding spacers 4113 extending along the axial direction and the radial direction of the cylinder and uniformly distributed along the circumferential direction of the cylinder, and one end of the second winding spacer 4113 near the center of the cylinder forms the through hole 4111. The first winding separator 4112 and the second winding separator 4113 are disposed opposite to each other on the outer diameter side and the inner diameter side of the cylinder, an outer line groove 4114 is formed by two adjacent first winding separators 4112 and the outer circumferential surface of the cylinder, an inner line groove 4115 is formed by two adjacent second winding separators 4113 and the inner circumferential surface of the cylinder, the stator winding 412 is wound in the outer line groove 4114 and the inner line groove 4115 along the axial direction of the cylinder, and the stator winding 412 and the two adjacent second winding separators 4113 constitute the air intake duct 440.

Preferably, the stator core 411 is formed by stacking and pressing a plurality of silicon steel sheets 4116 having identical shapes along the axial direction of the cylinder, and the structure of the silicon steel sheets is shown in fig. 9.

Through the above arrangement of the stator core 411, the stator winding 412 can be wound in the outer wire slot 4114 and the inner wire slot 4115 of the stator core 411, and the air inlet 440 is still formed after the stator winding is distributed in the inner wire slot 4115. Therefore, most of the stator winding 412 of the starter motor 16 in this structure is located in the slot, and there is little leakage of the stator winding at both ends of the stator core 411. The conventional motor adopts a conventional winding mode, the whole winding is positioned at the inner side of the stator core, and a regular air inlet channel is difficult to form because the space at the inner side of the stator core is limited, even if the air inlet channel is formed, the air inlet channel is narrow, the air passing is not facilitated, and mushroom windings are formed at two ends of the stator core. Compared with the two, the starting motor 16 with the structure has the advantages of shortened length in the axial direction and reduced overall volume. Therefore, when the starting motor 16 with the structure is used for the rotor system, the axial length of the whole rotor system can be greatly shortened, and the running stability of the rotor system can be improved. Meanwhile, the starter motor 16 of the present structure is formed with the air inlet channel 440 for air or cooling air to pass through on the motor stator 410, which is beneficial to heat dissipation of the motor stator 410 and the first rotating shaft 14, and meanwhile, when the starter motor 16 is used at the front end of a compressor or other devices requiring air intake, air intake of the rear end device is not blocked, and the axial length of the rotor system is not increased.

Preferably, as shown in fig. 10, the structure of the stator core 411 may be further optimized, that is, the end face slots 4117 are disposed at the two ends of the stator core 411 corresponding to the outer line slots 4114 and the inner line slots 4115, so that the whole winding is disposed in the slots, and the overall wiring of the starter motor 16 is cleaner.

Preferably, the surface of the stator core 411 is coated with an insulating layer or with an insulating paint.

Preferably, the first winding separator 4112 and the second winding separator 4113 are provided in 10, 16, 18, 24, etc.

Preferably, in order to facilitate heat dissipation from the motor stator 410 and the first rotating shaft 14 and air intake from the air intake duct 440, the starter motor 16 of this configuration may not be provided with a left and a right end caps, or may be provided with a left and a right end caps, but may be provided with mesh-shaped air holes.

Example two

The present embodiment differs from the embodiment in that, as shown in fig. 11, a regenerator 3 is provided in the present embodiment.

In the structure of the regenerator 3 provided in this embodiment, the regenerator 3 has a first inlet 31, a first outlet 32, a second inlet 33, and a second outlet 34. When the heat regenerator 3 is arranged, the air inlet end of the air compressor 11 is communicated with the outside, the air outlet end of the air compressor 11 is communicated with the first inlet 31 of the heat regenerator, the first outlet 32 of the heat regenerator is communicated with the inlet of the combustion chamber 13, the air outlet end of the combustion chamber 13 is communicated with the air inlet end of the high-pressure turbine group 12, the air outlet end of the high-pressure turbine group 12 is communicated with the air inlet end of the low-pressure turbine group 21, and air discharged by the high-pressure air compressor 11 enters the heat regenerator 3 for heat exchange and temperature rise, and then enters the combustion chamber 13. The flue gas chamber 25 is arranged at one side of the low-pressure turbine group 21, the inlet of the flue gas chamber 25 is communicated with the exhaust end of the low-pressure turbine group 21, the outlet of the flue gas chamber 25 is in butt joint communication with the second inlet 33 of the heat regenerator, the second outlet 34 of the heat regenerator is communicated with the outside, the gas at the outlet of the flue gas chamber 25 is discharged to the outside after being subjected to heat exchange and temperature reduction, the outlet of the flue gas chamber 25 can be square or in other shapes, and the second outlet 34 of the heat regenerator is communicated with the outside.

In this embodiment, the first inlet 31 and the second outlet 34 of the regenerator are cold ends, the first outlet 32 and the second inlet 33 are hot ends, the first inlet 31 and the first outlet 32 form a first channel, the second inlet 33 and the second outlet 34 form a second channel, and the first channel and the second channel are not communicated.

In this embodiment, the flow direction of the micro gas turbine is: the gas firstly enters the compressor 11, is pressurized by the compressor 11 and then enters the hot end inlet of the regenerator 3, is heated into high-temperature and high-pressure gas through heat exchange in the regenerator 3, then enters the inlet of the combustion chamber 13, is combusted in the combustion chamber 13 to generate high-temperature gas, the high-temperature gas is sprayed out from the outlet of the combustion chamber 13 to push the high-pressure turbine group 12 to rotate and expand to do work, the high-pressure turbine group 12 is coaxially connected with the compressor 11, and the high-pressure turbine group 12 further drives the compressor 11 to rotate to perform air inlet diffusion, meanwhile, high-temperature tail gas enters the inlet of the flue gas chamber 25, directly pushes the low-pressure turbine group 21 in the flue gas chamber 25 to rotate at high speed, the low-pressure turbine group 21 drives the generator 22 to generate power, tail gas enters the cold end of the regenerator 3 through the outlet of the flue gas chamber 25 at the other end of the low-pressure turbine group 21, and is discharged out of the micro gas turbine after heat exchange.

Preferably, the heat regenerator 3 is arranged outside the combustion chamber 13 in a surrounding way, the heat regenerator 3 is an annular or square box body, and the heat regenerator 3 is integrally or separately arranged, and when separately arranged, one or more heat regenerators are uniformly or unevenly arranged.

In another structure of the regenerator 3 provided in this embodiment, the regenerator 3 is further provided with a third inlet 35 and a third outlet 36, the third inlet 35 and the third outlet 36 form a third channel, and the third channel is not communicated with the first channel and the second channel.

At this time, the exhaust end of the high-pressure turbine group 12 is further communicated with the third inlet 35 of the regenerator, the third outlet 36 of the regenerator is communicated with the air inlet end of the low-pressure turbine group 21, and the air at the exhaust end of the high-pressure turbine group 12 enters the low-pressure turbine group 21 after undergoing heat exchange and temperature reduction.

In this embodiment, due to the high conversion rate of the low-pressure turbine set 21, the high-temperature fuel gas at the outlet of the combustion chamber 13 enters the regenerator 3 for heat exchange, and then is ejected from the other outlet of the regenerator 3 to push the high-pressure turbine set 12 to rotate and expand for doing work, so as to improve the heat energy absorption rate, the high-temperature fuel gas pushes the tail gas after the high-pressure turbine set 12 rotates and expands for doing work to enter the inlet of the flue gas chamber 25, and further pushes the low-pressure turbine set 21 in the flue gas chamber 25 to rotate at a high speed, and the low-pressure turbine set 21 drives the generator 22 to generate power. Although the high temperature gas enters the regenerator 3 to cause the loss of gas velocity, the residual velocity can still push the low pressure turbine set 21 to work for energy conversion, so that the overall conversion efficiency of the micro gas turbine is improved.

Example III

In this embodiment, a low pressure rotor system structure is provided.

As shown in fig. 12, the low pressure rotor system includes a second rotating shaft 23, a low pressure bearing set 24;

The second rotating shaft 23 comprises a low-pressure turbine shaft and a low-pressure motor shaft, the low-pressure turbine shaft and the low-pressure motor shaft are connected through a coupling, the low-pressure turbine group 21 is arranged on the low-pressure turbine shaft, and the generator 22 is arranged on the low-pressure motor shaft;

The low-pressure turbine set 21 includes a centrifugal turbine 211 and an axial turbine 212, a first bearing 241 is disposed between the centrifugal turbine 211 and the axial turbine 212, a second bearing 242 and a third bearing 243 are disposed between the low-pressure turbine set 21 and the coupling, and the shaft of the low-pressure turbine is rotatably connected with the motor body through a fourth bearing 244 and a fifth bearing 245.

The low-pressure turbine shaft has longer wheelbase to the low-pressure turbine shaft passes through the shaft coupling with the low-pressure motor shaft and connects, can keep apart the heat of low-pressure turbine end through this kind of mode, can bear the great axial thrust of low-pressure turbine end, the setting in the low-pressure turbine end flue space of being convenient for simultaneously, compare with connecting low-pressure turbine group 21 and motor 22 through an integral axle, the shafting structure has higher stability, in addition this connected mode makes things convenient for the change maintenance of bearing spare part.

In this embodiment, the low-pressure casing includes a first casing and a second casing, the first casing and the second casing are connected by a coupling, wherein the first bearing 241, the second bearing 242, the third bearing 243, the low-pressure turbine set 21 are disposed in the first casing, and the generator 22, the fourth bearing 244 and the fifth bearing 245 are disposed in the second casing.

In one specific structure provided in this embodiment, the first bearing 241, the second bearing 242, the third bearing 243, the fourth bearing 244, and the fifth bearing 245 are a first radial bearing, a thrust bearing, a second radial bearing, a third radial bearing, and a fourth radial bearing, respectively;

The first radial bearing is arranged between the centrifugal turbine 211 and the axial turbine 212, the thrust bearing and the second radial bearing are arranged between the low-pressure turbine group 21 and the generator 22, the thrust bearing is close to the low-pressure turbine group 21, the second radial bearing is close to the coupler, and the generator 22 is rotatably arranged between the third radial bearing and the fourth radial bearing.

Here, the third radial bearing and the fourth radial bearing may be further provided as thrust bearings, and the corresponding bearing types are provided, which will not be described in detail here.

Preferably, the first radial bearing, the thrust bearing, the second radial bearing are non-contact bearings, and the third radial bearing and the fourth radial bearing are non-contact bearings or contact bearings.

Preferably, the thrust bearing adopts an aero-magnetic mixed thrust bearing or an air thrust bearing or a magnetic bearing, the first radial bearing and the second radial bearing adopt aero-static pressure mixed radial bearings or aero-magnetic mixed radial bearings, and the third radial bearing and the fourth radial bearing adopt aero-static pressure mixed radial bearings or aero-magnetic mixed radial bearings or ball bearings.

Because the low-pressure turbine group 21 is arranged in the flue gas chamber through the low-pressure turbine shaft, a non-contact bearing is required to be arranged on the low-pressure turbine shaft so as to effectively isolate the heat in the flue gas chamber 25, prevent the heat from being conducted to the shaft of the low-pressure turbine to cause the damage of the generator, and improve the reliability and safety of the power generation system of the gas turbine; the power is respectively transmitted with the shaft of the low-voltage motor, and the shaft is connected through the coupling, so that the bearing capacity of each shaft can be effectively decomposed while the disassembly, assembly and maintenance of the low-voltage motor are convenient, and the deformation of the rotating shaft caused by overlong shaft distance is prevented.

Preferably, the thrust bearing and the second radial bearing may be provided as an integral bearing having both radial and axial support.

As shown in fig. 13 and 14, the integrated bearing 200 includes: a first bearing body 2200, a thrust disc 2300, and a second bearing body 2400; the thrust disc 2300 is fixedly connected to the low-pressure turbine shaft 100 or integrally formed therewith; the first bearing body 2200 and the second bearing body 2400 are both sleeved on the low-pressure turbine shaft 100 and positioned at both sides of the thrust disc 2300; the first bearing body 2200 has a radial bearing portion 2210 and a thrust bearing portion 2220 integrally formed, the radial bearing portion 2210 and the low-pressure turbine shaft 100 having a predetermined radial gap S1 in the radial direction, the thrust bearing portion 2220 being mounted opposite to the thrust disk 2300 in the axial direction and having a predetermined first axial gap S2; the second bearing body 2400 is mounted axially opposite the thrust disc 2300 with a predetermined second axial gap S3; the integrated bearing 200 further includes a first bearing housing 2500 and a first bearing end cap 2600, wherein the first bearing housing 2500 is covered on the outer circumferences of the first bearing body 2200, the thrust disc 2300 and the second bearing body 2400, and the first bearing end cap 2600 is mounted on one end of the second bearing body 2400 of the low-pressure turbine shaft 100, fixes the second bearing body 2400 in the axial direction, and is in transition fit with the first bearing housing 2500.

Specifically, the integrated gas bearing of the present embodiment may be any one of a hydrostatic gas bearing, a hydrodynamic gas bearing, or a dynamic-static pressure mixed gas bearing.

When it is provided as a hydrostatic gas bearing, a first annular air chamber 2230 is provided between the outer periphery of the radial bearing portion 2210 of the first bearing body 2200 and the first bearing housing 2500, and a first through hole 2240 penetrating the first annular air chamber 2230 and the radial gap S1 is provided at the bottom of the first annular air chamber 2230;

A second annular air cavity 2250 is provided between the thrust bearing portion 2220 of the first bearing body 2200 and the first bearing housing 2500, and a second through hole 2260 penetrating the second annular air cavity 2250 and the first axial gap S2 is provided at the bottom of the second annular air cavity 2250;

A third annular air cavity 2270 is arranged between the second bearing body 2400 and the first bearing end cover 2600, and a third through hole 2280 penetrating the third annular air cavity 2270 and the second axial gap S3 is arranged at the bottom of the third annular air cavity 2270;

Meanwhile, the first bearing housing 2500 is also provided with a first air inlet 2510 and a second air inlet 2520 for communicating the first annular air cavity 2230 and the second annular air cavity 2250 with an external air source, and the first bearing end cover 2600 is provided with a third air inlet 2610 for communicating the third annular air cavity 2270 with the external air source.

As shown in fig. 14, in the present embodiment, the first through hole 2240, the second through hole 2260, and the third through hole 2280 are preferably stepped holes, specifically: the diameter of one side of the step hole far away from the gap is large, the diameter of one side of the step hole near the gap is small, and meanwhile, the section of the diameter-changing part of the step hole can be funnel-shaped or conical. Thus, the processing is convenient, and the gas pressure in the gap is not influenced. Because the aperture of the inlet holes needs to be smaller than a certain value in order to satisfy the gas pressure in the gap, the inlet holes with small diameters are difficult to process and are easy to be blocked.

Preferably, the first through holes 2240 of the present embodiment are provided in plurality and uniformly distributed along the circumferential direction of the radial bearing portion 2210 to form a stable pressure air film in the circumferential direction of the low pressure turbine shaft 100, and more smoothly support the low pressure turbine shaft 100 in the circumferential direction.

Preferably, the first through holes 2240 of the present embodiment are provided in plurality and uniformly distributed along the axial direction of the radial bearing portion 2210 to form a stable pressure gas film in the axial direction of the low pressure turbine shaft 100, and more smoothly support the low pressure turbine shaft 100 in the axial direction.

Preferably, the second through holes 2260 of the present embodiment are provided in plural numbers and uniformly distributed on the end surface of the thrust bearing portion 2220 around the axis of the low-pressure turbine shaft 100, so as to support the low-pressure turbine shaft 100 and the rotor system more smoothly in the axial direction. As shown in fig. 15. Fig. 15 is a left side view of the first bearing body 2200.

Preferably, the third through holes 2280 of the present embodiment are provided in plurality and uniformly distributed on the end surface of the second bearing body 2400 centering on the axis of the low-pressure turbine shaft 100, so as to support the low-pressure turbine shaft 100 and the rotor system more smoothly in the axial direction.

When the integrated gas bearing of the present embodiment is provided as a dynamic pressure bearing, dynamic pressure generating grooves are provided on the inner diameter surface of the radial bearing portion 2210 of the first bearing body 2200 or the portion of the low pressure turbine shaft 100 where the radial bearing portion 2210 is mounted; dynamic pressure generating grooves are provided on an end surface of the thrust bearing portion 2220 of the first bearing body 2200 facing the thrust disk 2300 or an end surface of the thrust disk 2300 facing the thrust bearing portion 2220; dynamic pressure generating grooves are provided on an end surface of the second bearing body 2400 facing the thrust disc 2300 or an end surface of the thrust disc 2300 facing the second bearing body 2400.

When the integrated gas bearing of the present embodiment is provided as a hybrid dynamic-static pressure bearing, it has both the features of a hydrostatic bearing and a hydrodynamic bearing.

In the present integrated gas bearing, since the first bearing body 2200 includes both the radial bearing portion 2210 and the thrust bearing portion 2220, it is sufficient to process the thrust bearing portion 2220 with respect to the axial direction during the processing, to ensure the perpendicularity between the axial direction and the working surface of the thrust bearing portion 2220, or to process the inner diameter of the radial bearing portion 2210 with respect to the working surface of the thrust bearing portion 2220, and to ensure the perpendicularity between the working surface of the thrust bearing portion 2220 and the axial direction. The processing technology is simple and easy to operate, the processing precision is high, meanwhile, the precision of combined assembly is not considered in the assembly process, and the assembly technology is simple.

Example IV

Another low pressure rotor system configuration is provided in this implementation.

As shown in fig. 16, the low pressure rotor system includes a second rotating shaft 23, a low pressure bearing group 24;

wherein the second rotating shaft 23 is an integral rotating shaft;

The second rotating shaft 23 is provided with a low-pressure turbine group 21 and a generator 22, the low-pressure turbine group 21 comprises a centrifugal turbine 211 and an axial turbine 212, a first bearing 241 is arranged between the centrifugal turbine 211 and the axial turbine 212, a second bearing 242 and a third bearing 243 are arranged between the low-pressure turbine group 21 and the generator 22, and a fourth bearing 244 is arranged on one side of the generator 22 far away from the low-pressure turbine group 21.

Preferably, the first bearing 241, the second bearing 242, the third bearing 243, and the fourth bearing 244 are a first radial bearing, a second radial bearing, a thrust bearing, and a third radial bearing, respectively;

The first radial bearing is arranged between the centrifugal turbine 211 and the axial turbine 212, the second radial bearing and the thrust bearing are arranged between the low-pressure turbine group 21 and the generator 22, the second radial bearing is close to the low-pressure turbine group 21, the thrust bearing is close to the generator 22, and a third radial bearing is arranged at one end of the generator 22 away from the low-pressure turbine group 21.

Preferably, the first radial bearing, the second radial bearing and the thrust bearing are non-contact bearings, and the third radial bearing is a non-contact bearing or a contact bearing.

Preferably, the thrust bearing adopts an air-magnetic hybrid thrust bearing or an air thrust bearing or a magnetic bearing, the first radial bearing and the second radial bearing adopt an air-dynamic-static hybrid radial bearing or an air-magnetic hybrid radial bearing, and the third radial bearing adopts an air-dynamic-static hybrid radial bearing or an air-magnetic hybrid radial bearing or a ball bearing.

Because the low-pressure turbine group is arranged in the flue gas chamber 25 through the second rotating shaft 23, a non-contact bearing is required to be arranged on the low-pressure turbine rotating shaft to effectively isolate the heat in the flue gas chamber 25, so that the damage of the generator 22 caused by heat conduction to a motor shaft is prevented, and the reliability and the safety of a gas turbine power generation system are improved. The low-pressure turbine shaft has low rotating speed, the radial load and the axial thrust of the rotating shaft are greatly reduced compared with those of a conventional integrated high-speed miniature gas turbine, and the strength requirement on the rotating shaft is also reduced, so that the integrated rotating shaft can be used for connecting the low-pressure turbine group 21 and the motor 22, the number of parts is reduced, and the design reliability is improved.

The miniature gas turbine has a simple and compact structure, saves installation space, is convenient to install and transport rapidly, and can well meet the small-scale and decentralized requirements of distributed power supply; the device has the advantages of few moving parts, simple and compact structure, good reliability, low manufacturing cost and low maintenance cost; the environment adaptability is good, and the power supply quality is high.

The running reliability of the whole system is up to 99.996%, and the average annual shutdown maintenance time is not more than 2 hours. The single machine power of the miniature gas turbine is 10-100 KW, and the miniature gas turbine can operate at step power and step rotating speed, and the highest rotating speed reaches 140000RPM; the fuel consumption is low.

Preferably, the speed of the micro-combustion engine of the 15KW strip heat regenerator is 0-140000 RPM, and when the fuel is kerosene, the oil consumption is 50-600 g/kWh; when the fuel is natural gas, the natural gas consumption is 0.15m ³/kWh～0.5m³/kWh. The speed of the micro-combustion engine without a heat regenerator is 0-140000 RPM, and when the fuel is kerosene, the oil consumption is 400-1000 g/kWh; when the fuel is natural gas, the natural gas consumption is 0.4m ³/kWh～1m³/kWh.

Preferably, the speed of the micro-combustion engine of the 45KW strip heat regenerator is 0-80000 RPM, and when the fuel is kerosene, the oil consumption is 200-500 g/kWh; when the fuel is natural gas, the natural gas consumption is 0.2m ³/kWh～0.5m³/kWh. The speed of the micro-combustion engine without a heat regenerator is 0-80000 RPM, and when the fuel is kerosene, the oil consumption is 400-900 g/kWh; when the fuel is natural gas, the natural gas consumption is 0.5m ³/kWh～1m³/kWh.

The above description is only illustrative of the preferred embodiments of the present application and of the principles of the technology employed. It will be appreciated by persons skilled in the art that the scope of the application referred to in the present application is not limited to the specific combinations of the technical features described above, but also covers other technical features formed by any combination of the technical features described above or their equivalents without departing from the inventive concept. Such as the features described above, have similar functions to those disclosed in the present application (but are not limited to).

Claims

1. A multistage turbine type miniature gas turbine is characterized by comprising a high-pressure machine and a low-pressure machine;

the air inlet end of the air compressor is communicated with the outside, the air outlet end of the air compressor is communicated with the inlet end of the combustion chamber, the outlet end of the combustion chamber is communicated with the air inlet end of the high-pressure turbine group, the air outlet end of the high-pressure turbine group is communicated with the air inlet end of the low-pressure turbine group, the air outlet end of the low-pressure turbine group is communicated with the inlet of the flue gas chamber, and the outlet of the flue gas chamber is communicated with the outside;

the low-pressure rotor system comprises a second rotating shaft and a low-pressure bearing group;

the low-pressure turbine set comprises a centrifugal/centripetal turbine and an axial turbine, a first bearing is arranged between the centrifugal/centripetal turbine and the axial turbine, a second bearing and a third bearing are arranged between the low-pressure turbine set and the shaft coupling, the low-pressure turbine set is rotationally connected with the motor body through a fourth bearing and a fifth bearing, the low-pressure box comprises a first box and a second box, the first box is connected with the second box through the shaft coupling, the first bearing, the second bearing, the third bearing and the low-pressure turbine set are arranged in the first box, the generator, the fourth bearing and the fifth bearing are arranged in the second box, and the first bearing, the second bearing, the third bearing, the fourth bearing, the fifth bearing are respectively a first radial bearing, a thrust bearing, a second radial bearing, a third radial bearing and a fourth radial bearing;

The first radial bearing is arranged between the centrifugal/radial turbine and the axial turbine, the thrust bearing and the second radial bearing are arranged between the low-pressure turbine set and the generator, the thrust bearing is close to the low-pressure turbine set, the second radial bearing is close to the coupler, the generator is rotatably arranged between the third radial bearing and the fourth radial bearing, the first radial bearing, the thrust bearing and the second radial bearing are all non-contact bearings, the third radial bearing and the fourth radial bearing are all non-contact bearings or contact bearings, the thrust bearing adopts a gas-magnetic hybrid thrust bearing or an air thrust bearing or a magnetic bearing, the first radial bearing and the second radial bearing adopt a gas-dynamic-static pressure hybrid radial bearing or a gas-magnetic hybrid radial bearing, the third radial bearing and the fourth radial bearing adopt a gas-dynamic-static pressure hybrid radial bearing or a gas-magnetic hybrid radial bearing or a ball bearing, and the thrust bearing and the second radial bearing are arranged into an integrated bearing;

The integrated bearing includes:

The thrust bearing part and the thrust disc are arranged oppositely in the axial direction and have a preset first axial gap, the second bearing body and the thrust disc are arranged oppositely in the axial direction and have a preset second axial gap, so that the thrust bearing is formed, the integrated bearing also comprises a first bearing shell and a first bearing end cover, the first bearing shell is covered on the peripheries of the first bearing body, the thrust disc and the second bearing body, and the first bearing end cover is arranged at one end of the second bearing body of the low-pressure turbine shaft, fixes the second bearing body in the axial direction and is in transition fit with the first bearing shell;

The integrated bearing is a hydrostatic gas bearing, a first annular air cavity is arranged between the outer periphery of a radial bearing part of the first bearing body and the first bearing shell, and a first through hole which penetrates through the first annular air cavity and the radial gap is formed in the bottom of the first annular air cavity; a second annular air cavity is arranged between the thrust bearing part of the first bearing body and the first bearing shell, and a second through hole which penetrates through the second annular air cavity and the first axial gap is formed in the bottom of the second annular air cavity;

A third annular air cavity is arranged between the second bearing body and the first bearing end cover, and a third through hole which penetrates through the third annular air cavity and the second axial gap is formed in the bottom of the third annular air cavity;

Simultaneously, the first bearing shell is also provided with a first air inlet and a second air inlet which are communicated with the first annular air cavity and the second annular air cavity and the external air source, the first bearing end cover is provided with a third air inlet which is communicated with the third annular air cavity and the external air source, and the first through hole, the second through hole and the third through hole are all provided with step holes, and specifically: the diameter of one side of the step hole far away from the gap is large, the diameter of one side of the step hole near the gap is small, and meanwhile, the section of the diameter-changing part of the step hole is funnel-shaped or cone-shaped.

2. The multi-stage turbine micro gas turbine of claim 1, wherein the high pressure rotor system comprises a first shaft, a high pressure bearing set;

Wherein the first rotating shaft is of an integrated structure;

3. The multi-stage turbine micro gas turbine of claim 1, wherein the high pressure rotor system comprises a first shaft, a bearing;

4. The multi-stage turbine micro gas turbine of claim 1, wherein the high pressure turbine set comprises a centripetal turbine and at least one axial turbine, or comprises only more than two axial turbines;

5. The multi-stage turbine micro gas turbine of claim 1, wherein the guide vanes coaxial with the high pressure turbine group are disposed opposite to each other at a position between adjacent high pressure turbines within the high pressure casing.

6. The multi-stage turbine micro gas turbine of claim 1, wherein the low pressure turbine set comprises a centrifugal turbine and at least one axial turbine, or a centripetal turbine and at least one axial turbine, or only two or more axial turbines;

7. The multi-stage turbine micro gas turbine of claim 1, wherein the low pressure casing has guide vanes disposed opposite to each other at a position between adjacent low pressure turbines, coaxial with the low pressure turbine group.

8. The multistage turbine micro gas turbine according to claim 1, wherein the combustion chamber is a rotary backflow combustion chamber or an axial flow combustion chamber, the axis of the combustion chamber is coaxial with the mounting shafts of the compressor and the high pressure turbine group, the combustion chamber is arranged on one side of the high pressure turbine group away from the compressor, or the combustion chamber is arranged between the high pressure turbine group and the compressor.

9. The multi-stage turbine micro gas turbine of claim 1, wherein a plurality of air inlets axially penetrating the motor stator are provided on the motor stator of the starting motor;

Wherein, the motor stator comprises a stator iron core and a stator winding;

10. The multi-stage turbine micro gas turbine of claim 1, further comprising a regenerator;

11. The multi-stage turbine micro gas turbine of claim 10, wherein the regenerator is further provided with a third inlet, a third outlet;

12. The multi-stage turbine micro gas turbine of claim 11, wherein the regenerator is circumferentially disposed outside the combustion chamber;

The heat regenerator is an annular or square box body;

13. A multi-stage turbine micro gas turbine as set forth in any of claims 1-12 wherein,

14. The multi-stage turbine micro gas turbine of claim 13, wherein the first, second, third, and fourth bearings are first, second, thrust, and third radial bearings, respectively;

15. The multi-stage turbine micro gas turbine of claim 14, wherein the first radial bearing, the second radial bearing, and the thrust bearing are all non-contact bearings, and the third radial bearing is a non-contact bearing or a contact bearing.

16. The multistage turbine micro gas turbine according to claim 15, wherein the thrust bearing is a gas-magnetic hybrid thrust bearing, an air thrust bearing, or a magnetic bearing, the first radial bearing and the second radial bearing are both gas-dynamic-static hybrid radial bearings, or a gas-magnetic hybrid radial bearings, and the third radial bearing is a gas-dynamic-static hybrid radial bearing, or a gas-magnetic hybrid radial bearing, or a ball bearing.