Gas turbine eccentricity compensation air foil bearing

Abstract

The application provides a gas turbine eccentricity compensation air floating bearing, which comprises a shell, an outer supporting ring and a plurality of air floating blocks, the shell is wrapped on the outer circumferential surface of the outer supporting ring, an air inlet is arranged on the shell, and an equalizing ring cavity in communication with the air inlet is formed between the outer supporting ring and the shell; the plurality of air floating blocks are fixedly arranged on the inner circumferential surface of the outer supporting ring in a circumferential array, a gas passage hole penetrating through the outer supporting ring in a radial direction is arranged on the outer supporting ring at a position corresponding to each air floating block, a gas supply hole penetrating through the thickness direction of the air floating block in a radial direction is arranged on the air floating block at a position corresponding to the gas passage hole, and the gas passage hole is in communication with the equalizing ring cavity and the gas supply hole; the air floating bearing is improved on the basis of a conventional air floating bearing, the gas film thickness is changed through gas film pressure control, and the purpose of compensating the eccentricity of the shaft in the air floating bearing is expected to be achieved.

Description

Technical Field

[0001] This invention belongs to the field of gas turbines, especially micro gas turbines, and the field of gas bearing technology, specifically relating to an eccentrically compensated air bearing for gas turbines. Background Technology

[0002] Gas turbines are characterized by using a continuously flowing gas as the working fluid to drive the impeller at high speed, which in turn drives the power shaft at high speed. The power shaft of a gas turbine rotates at high speed continuously for extended periods, thus requiring far greater concentricity from the downstream shaft than ordinary power equipment. Even a slight eccentricity can significantly reduce the shaft's fatigue life during continuous high-speed rotation. While eccentricity is unavoidable due to manufacturing and assembly tolerances, the issue of eccentricity compensation for high-speed shafts in gas turbines has not received sufficient attention.

[0003] Considering actual operating conditions, the inventors believe that the bearings and couplings can compensate for shaft rotational eccentricity to a certain extent. Gas turbine bearings often employ air-bearing bearings. Conventional grease-lubricated bearings generate heat through friction during high-speed shaft rotation, which can transfer to the bearing and cause the grease to deteriorate at high temperatures, leading to bearing failure. Air-bearing bearings, however, continuously fill the gap between the bearing and the shaft with air, using film pressure to suspend the shaft, thus avoiding the problem of grease deterioration at high temperatures. However, another problem with air-bearing bearings is that the gap between the shaft and bearing allows for the formation of a high-pressure film. When the shaft is subjected to radial forces, such as downward gravity, it will slightly shift downwards, meaning the lower film thickness will be less than the upper film thickness. This creates a slight eccentricity between the shaft's centerline and the air-bearing bearing's centerline, affecting the air-bearing bearing's ability to correct the gas turbine shaft eccentricity. Summary of the Invention

[0004] Based on the above-mentioned prior art, the purpose of this invention is to provide a gas turbine eccentric compensation air bearing, which is an improvement on the traditional air bearing. By controlling the air film pressure to change the air film thickness, it is expected to compensate for the eccentricity of the central shaft of the air bearing.

[0005] The technical solution adopted in this invention is as follows: an eccentric compensation air bearing for a gas turbine, comprising a housing, an outer support ring, and multiple air floats. The housing covers the outer circumferential surface of the outer support ring and has an air inlet. The main body of the outer support ring is a rigid ring body, with radial protrusions on both sides of its outer circumferential surface forming ribs. The inner surfaces of the two ribs, the inner circumferential surface of the housing, and the portion of the outer circumferential surface of the outer support ring located between the two ribs form a pressure equalization ring cavity communicating with the air inlet.

[0006] The plurality of air flotation blocks are fixedly arranged in a circumferential array on the inner circumferential surface of the outer support ring. A vent hole is provided on the outer support ring at the position corresponding to each air flotation block, and an air supply hole is provided on the air flotation block at the position corresponding to the vent hole, which is in the thickness direction of the air flotation block. The vent hole connects the pressure equalization ring cavity and the air supply hole.

[0007] The air flotation block has a central through hole extending axially in its middle. Two side through holes extending axially are respectively arranged at a certain distance on both sides of the central through hole. One end of each side through hole is blocked, and the other end is connected to the corresponding end of the central through hole. The central through hole has one end blocked, and the other end is connected to the corresponding ends of the two side through holes. An air supply through hole radially penetrates the thickness direction of the air flotation block and intersects the central through hole. The width of the air supply through hole is the same as the diameter of the central through hole. A throttling component is installed inside the central through hole. Under pressure, the throttling component slides left and right to control the opening degree of the air supply through hole.

[0008] Multiple pressure feedback holes are provided on the inner surface of the air flotation block at positions corresponding to the two side through holes. The pressure feedback holes are connected to the side through holes, thereby feeding back the air film pressure on the inner surface of the air flotation block to the throttling component in the central through hole.

[0009] Furthermore, the air flotation block includes an air flotation block body, a first end cap, and a second end cap. The central through hole and the side through holes are both formed on the air flotation block body. The first end cap and the second end cap are respectively fixedly installed at both ends of the air flotation block body. A connecting groove is formed on the first end cap, which connects one end of the central through hole and one end of the two side through holes. The second end cap blocks the other end of the two side through holes. The pressure feedback holes are set in two rows corresponding to the positions of the two side through holes, and both are set on the air flotation block body.

[0010] Furthermore, the throttling assembly includes a piston rod, a first spring, and a second spring. The piston rod is a bidirectional piston structure integrally formed by a connecting rod and piston cylinders on both sides. The first spring and the second spring are respectively housed in the piston cylinders on both sides. The end of the first spring away from the piston rod is limited by a first limiting member, and the end of the second spring away from the piston rod is limited by a second limiting member.

[0011] The first limiting member can be a first end cap, and the connecting groove is a recessed groove structure opened on the inner side of the first end cap, specifically a V-shaped recessed groove, to connect the central through hole and the two side through holes; the second limiting member can be a second end cap or an independent adjusting screw.

[0012] When the second limiting component uses an adjusting screw, the second end cover is provided with a through hole corresponding to the central through hole for the adjusting screw to pass through. The adjusting screw is screwed into the central through hole, and the position of the throttling component can be adjusted by screwing the adjusting screw.

[0013] Furthermore, multiple axially extending positioning bosses are evenly distributed on the inner circumferential surface of the outer support ring, and a radially recessed mounting groove is formed between every two positioning bosses. The mounting groove is used to position and install the air flotation block, and the vent hole is opened at the position corresponding to the mounting groove.

[0014] Furthermore, the number of air flotation blocks can be six, eight, or twelve.

[0015] The present invention also claims protection for a gas turbine that employs the aforementioned air bearing, wherein a gas heat exchanger is connected in series on a gas pipeline connected to the air inlet of the air bearing, and the gas in the gas pipeline is heated by the waste heat of the gas turbine exhaust gas, so that the gas entering the air bearing has a higher initial temperature.

[0016] Specifically, the gas heat exchanger has an outer shell and an inner shell nested together. The gas supply gas from the gas pipe flows through the internal space of the inner shell, while the exhaust gas from the gas turbine flows through the intermediate annular space between the outer and inner shells, with the flow direction opposite to the gas flow direction inside the inner shell. The intermediate annular space between the outer and inner shells is provided with first helical fins, forming a first helical channel that increases the flow path of the gas turbine exhaust gas. Inside the inner shell, there is a central tube shell and a second helical fin located between the central tube shell and the inner shell. The second helical fins form a second helical channel, which communicates with the internal space of the central tube shell through slits distributed on the central tube shell. The first and second helical fins are distributed on both sides of the inner shell, thus serving as heat exchange plates for heat transfer.

[0017] The air bearing provided by this invention can change the thickness of the air film below the shaft, thereby using the high-pressure air film to push the rotating shaft upward, partially compensating for the eccentricity of the shaft when using air bearings in gas turbines, and reducing its eccentricity; in addition, the waste heat of the gas turbine exhaust gas is used to heat the supply gas of the air bearing, the initial temperature of the gas forming the high-pressure air film has increased, reducing the compressibility of the gas, avoiding the thinning of the air film thickness due to gas compression, and further compensating for the eccentricity of the shaft in the air bearing. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the air bearing assembly of the present invention;

[0019] Figure 2 This is a three-dimensional structural schematic diagram of the air bearing of the present invention;

[0020] Figure 3 This is an overall sectional view of the air bearing of the present invention;

[0021] Figure 4 This is an exploded view of the air bearing of the present invention;

[0022] Figure 5 This is a three-dimensional structural diagram of the outer support ring in the air bearing of the present invention;

[0023] Figure 6 This is an exploded view of the air-bearing block in the air-bearing structure of the present invention;

[0024] Figure 7 This is a schematic diagram of the combined state of the air float blocks in the air float bearing of the present invention;

[0025] Figure 8 This is a cross-sectional view of the air float block along the central blind hole in the air float bearing of the present invention;

[0026] Figure 9 This is a cross-sectional view of the axial through hole of the air float block in the air float bearing of the present invention.

[0027] Figure 10 This is a schematic diagram of the structure of the first end cap in the air bearing of the present invention;

[0028] Figure 11 This is a schematic diagram of the combined state of the throttling component in the air bearing of the present invention;

[0029] Figure 12 This is an exploded view of the throttling component in the air bearing of the present invention;

[0030] Figure 13 This is a schematic diagram of the air supply structure of the air bearing of the present invention;

[0031] Figure 14 This is an overall cross-sectional view of the gas heat exchanger in the air-bearing structure of the present invention;

[0032] In the diagram: 1. Air bearing; 1-1. Upper housing; 1-2. Lower housing; 2. Shaft; 3. Air inlet;

[0033] 4. Outer support ring; 4-1. Rib ring; 4-2. Positioning boss; 4-3. Mounting groove; 4-4. Vent hole;

[0034] 5. Air flotation block; 5-1. Air flotation block body; 5-2. First end cap; 5-3. Second end cap; 5-4. Central through hole; 5-5. Side through hole; 5-6. Throttling assembly; 5-7. End cap fixing bolt; 5-8. Air flotation block body positioning bolt; 5-9. Air supply through hole; 5-10. Pressure feedback hole.

[0035] 5-2-1, Communicating groove; 5-6-1, Piston rod; 5-6-2, First spring; 5-6-3, Second spring; 5-6-4, Adjusting screw;

[0036] 6. Equalizing ring cavity, 7. Gas heat exchanger, 8. Gas pipeline. Detailed Implementation

[0037] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0038] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are for simplification and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0039] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0040] This invention provides an eccentrically compensated air bearing for gas turbines, see [link / reference]. Figure 1 This is a schematic diagram of the assembly of the air bearing of the present invention. The air bearing is used for positioning and supporting the blade shaft or the power shaft. Figure 1 The air bearing 1 shown supports the rotation of the shaft 2. Figure 2 This is a three-dimensional structural diagram of the air bearing of the present invention. Figure 3This is an overall sectional view of the air bearing of the present invention. The air bearing 1 consists of a housing, an outer support ring 4, and air floats 5 from the outside to the inside. Each air float 5 comprises multiple air floats arranged in a circumferential array, such as six, eight, or twelve. The shaft 2 is housed within a circular space surrounded by the multiple air floats 5. A high-pressure air film is formed between the outer surface of the shaft 2 and the inner surface of the air floats 5 to support the high-speed rotation of the shaft 2. The housing is composed of an upper housing 1-1 and a lower housing 1-2 fixedly connected by bolts. An air inlet 3 is provided on the housing for introducing gas into the interior. Figure 2 In the illustrated embodiment, the air inlet 3 is located on the upper housing 1-1. It is readily apparent that the air inlet 3 could also be located on the lower housing 1-2 or at the joint between the upper housing 1-1 and the lower housing 1-2. An outer support ring 4 is provided on the inner wall surface of the upper housing 1-1 and the lower housing 1-2, and the plurality of air flotation blocks 5 are uniformly and fixedly distributed along the circumferential direction on the inner wall surface of the outer support ring 4. (See [reference]). Figure 2 A pressure equalization ring cavity 6 is formed between the outer support ring 4 and the housing, which communicates with the air inlet 3. The outer support ring 4 is also provided with radial ventilation holes corresponding to the number of air floats 5. The pressure equalization ring cavity 6 supplies gas to the air floats 5 through the ventilation holes to continuously deliver it to the gap between the air floats 5 and the shaft 2.

[0041] Figure 5 This is a three-dimensional structural diagram of the outer support ring in the air bearing of the present invention, combined with... Figure 4 , Figure 5 The outer support ring 4 is a rigid circular ring structure. Both sides of the outer circumferential surface of the outer support ring 4 have radially protruding ribs 4-1. The outer circumferential surface of the ribs 4-1 seals against the inner circumferential surface of the housing (a graphite sealing ring or sealant can be added between the ribs 4-1 and the housing), thereby forming the equalizing ring cavity 6 between the two ribs 4-1. Multiple axially extending vent holes 4-4 are evenly distributed on the outer circumferential surface of the outer support ring 4 located between the two ribs 4-1. The vent holes 4-4 penetrate the wall thickness of the outer support ring 4. Multiple axially extending positioning bosses 4-2 are evenly distributed on the inner circumferential surface of the outer support ring 4. A radially recessed mounting groove 4-3 is formed between every two positioning bosses 4-2. The mounting groove 4-3 is used to position and install the air flotation block 5. The vent holes 4-4 are opened corresponding to the positions of the mounting grooves 4-3. See [reference needed]. Figure 5 The rib ring 4-1 is also provided with bolt holes, which correspond to the bolt holes inside the mounting groove 4-3, and are used to install bolts to fix the air flotation block 5 inside the mounting groove 4-3.

[0042] Figure 7 This is a schematic diagram of the air float block assembly state in the air float bearing of the present invention. Figure 6 This is an exploded view of the air float block in the air float bearing of the present invention. See also... Figure 6 , Figure 7 The air flotation block 5 includes an air flotation block body 5-1, a first end cap 5-2, a second end cap 5-3, and a throttling assembly 5-6. The first end cap 5-2 and the second end cap 5-3 are respectively fixedly installed at both ends of the air flotation block body 5-1 by end cap fixing bolts 5-7. The air flotation block body 5-1 is fixedly installed inside the mounting groove 4-3 of the outer support ring 4 by air flotation block body positioning bolts 5-8. A central through hole 5-4 extending axially is provided in the middle of the air flotation block body 5-1, and one end of the central through hole 5-4 is... The first end cap 5-2 is used for sealing, and its other end corresponds to the position of the through hole on the second end cap 5-3; the throttling assembly 5-6 is disposed inside the central through hole 5-4; a side through hole 5-5 extending axially is respectively provided on both sides of the central through hole 5-4 at a certain distance, and the two ends of the side through holes 5-5 are respectively sealed by the first end cap 5-2 and the second end cap 5-3, and a connecting groove is provided on the first end cap 5-2, which allows the central through hole 5-4 and the two side through holes 5-5 to be fluidly connected through the connecting groove. See also Figure 7 The air flotation block body 5-1 is also provided with a radially penetrating air supply hole 5-9 in the middle. The air supply hole 5-9 is a strip-shaped hole whose shape and position correspond to the air vent 4-4 on the outer support ring 4, so that the gas entering from the air inlet 3 can pass through the pressure equalization ring cavity 6, the air vent 4-4, and the air supply hole 5-9 in sequence and enter the gap between the air flotation block 5 and the shaft 2 to form an air film. The throttling component 5-6 can slide in the central through hole 5-4 to adjust the opening size of the air supply hole 5-9. The inner surface of the air flotation block 5 is also evenly distributed with two rows of axially distributed pressure feedback holes 5-10, and each row of pressure feedback holes 5-10 is connected to a side through hole 5-5.

[0043] The following is combined with Figure 8 and Figure 9 A more detailed introduction to the structure of the air flotation block is provided below. Figure 8 This is a cross-sectional view of the air float block along the central blind hole in the air float bearing of the present invention, as shown below. Figure 8 As shown, the air supply through-hole 5-9 penetrates the thickness direction of the air flotation block body 5-1 radially and simultaneously crosses the central through-hole 5-4. The width of the air supply through-hole 5-9 is the same as the diameter of the central through-hole 5-4. The throttling component 5-6 is a piston rod structure disposed in the central through-hole 5-4 and slidable along the axial direction of the central through-hole. When the throttling component 5-6 slides to the right, the opening length of the air supply through-hole 5-9 is larger. When the throttling component 5-6 slides to the left, the opening length of the air supply through-hole 5-9 decreases, the throttling effect increases, and the air film pressure on the inner wall of the air flotation block 5 is affected and becomes smaller accordingly. Figure 9This is a cross-sectional view of the axial through hole of the air float block in the air float bearing of the present invention. A pressure feedback hole 5-10 is provided on the air float block body 5-1. The pressure feedback hole 5-10 connects the side through hole 5-5 with the inner surface of the air float block body 5-1. The air film pressure can be gathered into the side through hole 5-5 through the pressure feedback hole 5-10. The right end of the side through hole 5-5 is closed by the second end cover 5-3, and its left end is connected to the connecting groove on the first end cover 5-2. The pressure can be transmitted to the throttling component 5-6 inside the central through hole 5-4 through the connecting groove.

[0044] Figure 10 A schematic diagram of the structure of the first end cap in the air bearing of the present invention is shown. The first end cap 5-2 is provided with a connecting groove 5-2-1. The connecting groove 5-2-1 is a sinking structure that connects the two side through holes 5-5 to the central through hole 5-4 so as to transmit the pressure feedback inside the side through holes 5-5 to the central through hole 5-4.

[0045] The throttling assembly 5-6 includes a piston rod 5-6-1, a first spring 5-6-2, a second spring 5-6-3, and an adjusting screw 5-6-4. (See also...) Figure 11 and Figure 12 The figures are a schematic diagram of the combined state of the throttling component in the air bearing of the present invention and an exploded view of the throttling component in the air bearing of the present invention. The piston rod 5-6-1 is a bidirectional piston structure composed of a connecting rod and piston cylinders on both sides. The piston cylinders on both sides respectively house a first spring 5-6-2 and a second spring 5-6-3. The end of the first spring 5-6-2 away from the piston rod 5-6-1 abuts against the communicating groove 5-2-1. The end of the second spring 5-6-3 away from the piston rod 5-6-1 is adjusted by the adjusting screw 5-6-4. The adjusting screw 5-6-4 passes through the through hole of the second end cover 5-3 and is screwed into the center through hole 5-4. Adjusting the position of the adjusting screw 5-6-4 can adjust the initial compression degree of the first spring 5-6-2 and the second spring 5-6-3. Of course, it is easy to imagine that the throttling component 5-6 may not be equipped with an adjusting screw, and the second end cover 5-3 may be a sealing plate without a through hole. After the throttling component 5-6 is installed into the center through hole 5-4, the end of the second spring 5-6-3 is directly blocked and limited by the second end cover 5-3.

[0046] Through the aforementioned air flotation block structure, when the shaft 2 rotates at high speed, a high-pressure air film is formed between the inner surface of multiple air flotation blocks 5 and the shaft 2. Affected by factors such as gravity, the horizontal position of the shaft 2 will be slightly biased downward, forming an eccentricity. At this time, the thickness of the air film below the shaft 2 is thinner than that above, and on the annular overall air film pressure distribution gradient, the pressure of the air film below is also slightly greater than that above. The pressure feedback hole 5-10 of the lower air flotation block 5 will transmit the air film pressure through the side through hole 5-5, the connecting groove 5-2-1, and the central through hole 5-4 to the throttling component 5-6, pushing the piston rod 5-6-1 to deviate in the direction that causes the air supply through hole 5-9 to open more significantly. The throttling effect of the air supply through hole 5-9 and the piston rod 5-6-1 is weakened, and the thickness of the lower air film rebounds, causing the center line of the shaft 2 to rise upward, partially compensating for the eccentricity of the shaft 2 and reducing its eccentricity.

[0047] Furthermore, the air supply for the air bearing 1 of the present invention can be heated using the waste heat from the exhaust gas of the gas turbine, see [link to relevant documentation]. Figure 13 and Figure 14 Figures 1 and 2 are schematic diagrams of the gas supply structure of the air bearing of the present invention and overall cross-sectional views of the gas heat exchanger in the air bearing of the present invention. As shown in the figures, the gas supply pipe 8 is connected to the air inlet 3 on the shell for gas supply. A gas heat exchanger 7 is connected in series on the gas supply pipe 8. The gas heat exchanger 7 uses the waste heat of the gas turbine exhaust gas to perform countercurrent heat exchange with the gas supplied by the gas supply pipe 8, thereby increasing the gas supply temperature of the air bearing 1, reducing the compressibility of the gas supplied, improving the pressure resistance of the high-pressure gas film, and avoiding its thinning due to compression, so as to compensate for the eccentricity. Figure 14 This example illustrates a specific embodiment of a gas heat exchanger; see [link to relevant documentation]. Figure 14 The gas heat exchanger 7 has an outer shell and an inner shell nested together. The gas supply gas from the gas pipe 8 flows through the internal space of the inner shell, and the exhaust gas from the gas turbine flows through the intermediate annular space between the outer shell and the inner shell, with the flow direction opposite to the gas flow direction inside the inner shell. Furthermore, a first spiral fin is provided in the intermediate annular space between the outer shell and the inner shell, forming a first spiral channel that increases the flow path of the gas turbine exhaust gas. A central tube shell and a second spiral fin located between the central tube shell and the inner shell are provided inside the inner shell. The second spiral fin forms a second spiral channel, which is connected to the internal space of the central tube shell through slits distributed on the central tube shell. The first and second spiral fins can be an integral structure, thus serving as heat exchange plates for heat transfer. The waste heat of the exhaust gas flowing through the first spiral channel is transferred to the second spiral channel through the first and second spiral fins to heat the gas supply temperature of the gas pipe 8.

[0048] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that, based on the technical solutions of the present invention, various modifications or variations of equivalent structures or equivalent processes that can be made by those skilled in the art without creative effort, or directly or indirectly applied to other related technical fields, are still within the scope of protection of the present invention.

Claims

1. A gas turbine eccentric compensation air bearing, characterized in that, It includes a shell, an outer support ring, and multiple air flotation blocks. The shell covers the outer peripheral surface of the outer support ring and has an air inlet. The main body of the outer support ring is a rigid ring body, and both sides of its outer peripheral surface are radially protruding to form ribs. The inner surfaces of the two ribs, the inner peripheral surface of the shell, and the portion of the outer peripheral surface of the outer support ring located between the two ribs form a pressure equalization ring cavity that communicates with the air inlet. The plurality of air flotation blocks are arranged in a circumferential array and fixedly disposed on the inner circumferential surface of the outer support ring. A vent hole is provided on the outer support ring at the position corresponding to each air flotation block, and an air supply hole is provided on the air flotation block at the position corresponding to the vent hole, which is radially penetrating the thickness direction of the air flotation block. The vent hole connects the pressure equalization ring cavity and the air supply hole. The air flotation block has a central through hole extending along its axial direction in the middle. A side through hole extending along its axial direction is provided on both sides of the central through hole at a certain distance. One end of the two side through holes is blocked and the other end is connected to the corresponding end of the central through hole. One end of the central through hole is blocked and the other end is connected to the corresponding end of the two side through holes. The air supply through-hole radially penetrates the thickness direction of the air float block and intersects the central through-hole. The width of the air supply through-hole is the same as the diameter of the central through-hole. A throttling component is provided inside the central through-hole. The throttling component slides left and right under pressure to control the opening degree of the air supply through-hole. Multiple pressure feedback holes are provided on the inner surface of the air flotation block at positions corresponding to the two side through holes. The pressure feedback holes are connected to the side through holes, thereby feeding back the air film pressure on the inner surface of the air flotation block to the throttling component in the central through hole.

2. The air bearing according to claim 1, characterized in that, The air flotation block includes an air flotation block body, a first end cap, and a second end cap. The central through hole and the side through holes are both formed on the air flotation block body. The first end cap and the second end cap are respectively fixedly installed at both ends of the air flotation block body. A connecting groove is formed on the first end cap, which connects the central through hole and one end of the two side through holes. The second end cap blocks the other end of the two side through holes. The pressure feedback holes are arranged in two rows, each corresponding to one of the two side through holes, and both are located on the air flotation block body.

3. The air bearing according to claim 1 or 2, characterized in that, The throttling assembly includes a piston rod, a first spring, and a second spring. The piston rod is a bidirectional piston structure composed of a connecting rod and piston cylinders on both sides. The first spring and the second spring are respectively housed in the piston cylinders on both sides. The end of the first spring away from the piston rod is limited by a first limiting member, and the end of the second spring away from the piston rod is limited by a second limiting member.

4. The air bearing according to claim 3, further characterized in that, The first limiting member is a first end cap, and the second limiting member is a second end cap.

5. The air bearing according to claim 3, characterized in that, The first limiting member is a first end cap, and the second limiting member is an adjusting screw, which is threaded into the central through hole.

6. The air bearing according to claim 1, characterized in that, The outer support ring has a plurality of axially extending positioning bosses evenly distributed on its inner circumferential surface. A radially recessed mounting groove is formed between every two positioning bosses. The mounting groove is used to position and install the air flotation block. The vent hole is opened at the position corresponding to the mounting groove.

7. The air bearing according to claim 1 or 2, characterized in that, The number of air flotation blocks is six, eight, or twelve.

8. A gas turbine employing the air bearing as described in any one of claims 1-7, characterized in that, A gas heat exchanger is connected in series with the gas pipeline that is connected to the air inlet of the air bearing, and the gas in the gas pipeline is heated by the waste heat of the exhaust gas from the gas turbine.

9. The gas turbine according to claim 8, characterized in that, The gas heat exchanger has an outer shell and an inner shell nested together. The gas supply gas from the gas pipe flows through the internal space of the inner shell, while the exhaust gas from the gas turbine flows through the intermediate annular space between the outer and inner shells, with the flow direction opposite to that of the gas flow inside the inner shell. A first spiral fin is provided in the intermediate annular space between the outer and inner shells, forming a first spiral channel that increases the flow path of the gas turbine exhaust gas. Inside the inner shell, a central tube shell and a second spiral fin are provided between the central tube shell and the inner shell. The second spiral fin forms a second spiral channel, which communicates with the internal space of the central tube shell through slits distributed on the central tube shell. The first and second spiral fins are distributed on both sides of the inner shell, thus serving as heat exchange plates for heat transfer.

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