A gas turbine

Abstract

The present invention discloses a gas turbine, comprising a first rotating shaft and a second rotating shaft arranged in sequence along the axial direction, and a combustion chamber, a first compressor is installed at one end of the first rotating shaft axially away from the second rotating shaft, and a first turbine is installed at one end of the first rotating shaft axially close to the second rotating shaft, a second compressor is installed at one end of the second rotating shaft axially away from the first rotating shaft, and a second turbine and a third turbine are installed in sequence along the axial direction close to one end of the first rotating shaft, the intake end of the second compressor is connected to the exhaust end of the first compressor, the exhaust end of the second compressor is connected to the intake end of the combustion chamber, the exhaust end of the combustion chamber is connected to the inlet end of the third turbine, and the third turbine is a film-cooled turbine with a hollow structure. The gas turbine disclosed by the present invention has a reasonable layout of the compressor and the turbine, and can enhance the cooling of the turbine, thereby further increasing the temperature of the turbine inlet to improve the efficiency of the gas turbine.

Description

Technical Field

[0001] The present invention belongs to the field of thermal engines, and in particular relates to a gas turbine. Background Art

[0002] A gas turbine primarily consists of three components: a compressor, a combustion chamber, and a turbine, along with intake, exhaust, control, transmission, and other auxiliary systems. Using air as its medium, it is a rotary power machine that converts the heat energy generated by fuel combustion into mechanical work for external output. Its operating process is as follows: The rotating compressor, driven by the turbine, continuously draws in air from the atmosphere and compresses it to increase its pressure. The compressed air enters the combustion chamber, where it mixes with the injected fuel and burns, becoming high-temperature combustion gases. These gases then flow into the turbine, expand, and perform work. After this work, the pressure of the combustion gases drops to atmospheric pressure and is ultimately discharged into the atmosphere. The high-temperature combustion gases generated by the combustion and heating greatly enhance their work capacity, significantly increasing the turbine's work output and the compressor's power consumption, leaving ample surplus power for external output to drive the load.

[0003] Existing studies have shown that the thermal efficiency and power output of gas turbines increase with increasing turbine inlet temperature. Generally, for every 40°C increase in turbine inlet temperature, the output power of the gas turbine can be increased by 10% and the thermal efficiency can be increased by 1.5% [1]. However, the increase in turbine inlet temperature is subject to the temperature tolerance of the turbine blade material directly exposed to high-temperature gas, as well as the cooling effect of the turbine blade. A significant increase in turbine inlet temperature may lead to a decrease in the structural strength of the turbine blade, which in turn causes blade deformation or ablation failure. Therefore, the turbine blade directly determines the performance level of the gas turbine to a certain extent. How to increase the turbine inlet temperature while ensuring the long-life and safe operation of the gas turbine is a key technical problem in the development of high-performance gas turbines.

[0004] Li Xiaotang, Hou Lingyun, Yang Min, et al. Modern gas turbine technology[M]. Beijing: Aviation Industry Press, 2006: 23-24. Summary of the Invention

[0005] The purpose of the present invention is to provide a gas turbine that addresses the deficiencies in the prior art, rationally arranges the compressor and turbine, and can enhance the cooling of the turbine, thereby further increasing the temperature at the turbine inlet to improve the efficiency of the gas turbine.

[0006] The present invention adopts the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a gas turbine comprising a first rotating shaft and a second rotating shaft arranged in sequence along the axial direction, and a combustion chamber, wherein a first compressor is installed on an end of the first rotating shaft axially away from the second rotating shaft and a first turbine is installed on an end axially close to the second rotating shaft, a second compressor is installed on an end of the second rotating shaft axially away from the first rotating shaft and a second turbine and a third turbine are installed in sequence axially close to the end of the first rotating shaft, an intake end of the second compressor is connected to an exhaust end of the first compressor, an exhaust end of the second compressor is connected to an intake end of the combustion chamber, an exhaust end of the combustion chamber is connected to an inlet end of the third turbine, and the third turbine is a film-cooled turbine having a hollow structure.

[0008] Furthermore, at least one axial end of the second rotating shaft is provided with an at least partially built-in inner air bearing, and the inner air bearing has an air supply channel, and the air supply channel supplies cooling air to the third turbine through the interior of the second rotating shaft.

[0009] Furthermore, the end of the second rotating shaft provided with the inner air bearing has a nose cone, and the inner air bearing has a nose cone air supply hole.

[0010] Furthermore, the gas turbine further includes a plurality of first radial bearings, which are external radial air bearings sleeved on the outer circumference of the first rotating shaft and / or the second rotating shaft.

[0011] Furthermore, in the axial direction, the second turbine is located between the first turbine and the third turbine, and the combustion gas from the exhaust end of the combustion chamber passes through the third turbine, the second turbine and the first turbine in sequence and is discharged.

[0012] Furthermore, the gas turbine also includes a first stator blade assembly, which is located between the third turbine and the exhaust end of the combustion chamber and is arranged close to the third turbine. The stators in the first stator blade assembly are fluid-cooled blades with a hollow structure.

[0013] Furthermore, the second turbine is a film-cooled turbine with a hollow structure.

[0014] Furthermore, the gas turbine also includes a second stator blade assembly, which is located between the third turbine and the second turbine and is arranged close to the second turbine. The stator blades in the second stator blade assembly are fluid-cooled blades with a hollow structure.

[0015] Furthermore, the gas turbine also includes a first motor and a second motor, the first motor is mounted on the first rotating shaft and is located between the first compressor and the first turbine, or is located on the side of the first compressor away from the first turbine; the second motor is mounted on the second rotating shaft and is located on the side of the second compressor away from the third turbine.

[0016] Furthermore, the power of the first motor is greater than or equal to the power of the second motor.

[0017] Furthermore, the second rotating shaft includes a first shaft segment and a second shaft segment arranged axially therefrom, the first shaft segment and the second shaft segment are connected by a coupling, and the coupling has an air sealing cavity connecting the air paths in the first shaft segment and the second shaft segment.

[0018] Furthermore, the second motor is mounted on the second shaft segment.

[0019] Furthermore, the gas turbine includes an inner air bearing, which is located at an end of the second shaft segment axially away from the first shaft segment.

[0020] Furthermore, the first motor and / or the second motor is a superconducting motor, and the fuel of the gas turbine is reused as a coolant for the superconducting motor.

[0021] Furthermore, the pressure ratio of the second compressor is greater than or equal to the pressure ratio of the first compressor.

[0022] Furthermore, the second compressor is a centrifugal compressor.

[0023] Furthermore, the first compressor is selected from one or more of a centrifugal compressor, an axial flow compressor, and a diagonal flow compressor.

[0024] Furthermore, the gas turbine also includes a regenerator HR, which includes a first passage and a second passage for heat exchange, the exhaust end of the second compressor is connected to the intake end of the first passage, the intake end of the combustion chamber is connected to the exhaust end of the first passage, the exhaust end of the first turbine is connected to the intake end of the second passage, and the exhaust end of the second passage is connected to the external atmosphere or other external components.

[0025] According to an embodiment of the present invention, the gas turbine comprises a first compressor mounted on a first shaft and a second compressor mounted on a second shaft, with the intake end of the second compressor connected to the exhaust end of the first compressor. This improves the compressor pressure ratio, thereby facilitating enhanced gas turbine efficiency. Furthermore, by configuring the third turbine, which is connected to the exhaust end of the combustion chamber, as a hollow film-cooled turbine, the turbine is protected by a cooling film, further increasing the temperature of the gas flowing in front of the turbine and thereby improving the efficiency of the gas turbine. Furthermore, by arranging the first, second, and third turbines on the first and second shafts, the elevated temperature of the high-temperature gas can be more fully utilized, thereby improving the overall efficiency of the gas turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of a gas turbine according to one embodiment of the present invention;

[0027] Figure 2 for Figure 1 A partial schematic diagram of an embodiment of the third turbine;

[0028] Figure 3 for Figure 1 A partial schematic diagram of another embodiment of the third turbine;

[0029] Figure 4 for Figure 1 A partial schematic diagram of another embodiment of the third turbine;

[0030] Figure 5 for Figure 1 A partial schematic diagram of an embodiment of the second rotating shaft;

[0031] Figure 6 for Figure 1 A partial schematic diagram of an embodiment of an inner air bearing;

[0032] Figure 7 for Figure 1 A partial schematic diagram of another embodiment of an inner air bearing;

[0033] Figure 8 for Figure 1 A partial schematic diagram of another embodiment of the third turbine;

[0034] Figure 9 is a schematic structural diagram of a gas turbine according to another embodiment of the present invention;

[0035] Figure 10 is a schematic structural diagram of a gas turbine according to yet another embodiment of the present invention;

[0036] Figure 11 for Figure 10 A schematic structural diagram of an embodiment of the second rotating shaft;

[0037] Figure 12 is a schematic structural diagram of a gas turbine according to yet another embodiment of the present invention;

[0038] Figure 13 is a schematic structural diagram of a gas turbine according to yet another embodiment of the present invention;

[0039] Figure 14 FIG. 1 is a schematic structural diagram of a gas turbine according to yet another embodiment of the present invention.

[0040] Reference numerals: DETAILED DESCRIPTION

[0041] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present invention by illustrating examples of the present invention.

[0042] The efficiency of a gas turbine is positively correlated with the temperature in front of the turbine. However, when the temperature in front of the turbine is too high, exceeding the heat resistance limit of the turbine material, the turbine cannot continue to operate normally. Therefore, people are committed to developing materials with higher heat resistance, but the development progress is slow, and the high price of new materials has led to a significant increase in gas turbine costs.

[0043] The inventors discovered that air film cooling or liquid film cooling can protect the turbine and improve material stability at higher turbine inlet temperatures. However, simply using the centrifugal force of the turbine's rotation to increase the cooling air pressure often results in a pressure lower than or slightly higher than the static pressure inlet, thus failing to form an effective cooling air film. Liquid film cooling also requires high cooling fluid requirements, such as deionized water, and requires continuous consumption, making it difficult to reuse and increasing costs.

[0044] Therefore, there is an urgent need for a gas turbine that can improve turbine cooling, thereby increasing efficiency by raising the temperature before the turbine. This approach should ensure continuous and easy cooling, while also controlling manufacturing and modification costs. Furthermore, a rational layout of the compressor and turbine is required to fully utilize the elevated temperature of the gas.

[0045] To achieve the above purpose, if Figure 1 As shown, Figure 1 Schematic diagram of the structure of a gas turbine according to an embodiment of the present invention. The present invention provides a gas turbine, comprising a first rotating shaft 110 and a second rotating shaft 120 and a combustion chamber 400 arranged in sequence along the axial direction.

[0046] The first and second rotating shafts 110, 120 can be made of steel or other suitable metals, alloys, or composite materials. They are supported on the gas turbine housing or bearing housing via bearings. These bearings are preferably air bearings, but can also be non-contact bearings such as magnetic bearings or hybrid air-magnetic bearings, or some of them can be contact bearings such as ball bearings or roller bearings.

[0047] The first rotating shaft 110 and the second rotating shaft 120 may be coaxially arranged, with one axial end of the first rotating shaft 110 being opposite to one axial end of the second rotating shaft 120 .

[0048] The first compressor 210 is mounted on an end of the first rotating shaft 110 that is axially away from the second rotating shaft 120 , and the first turbine 310 is mounted on an end of the first rotating shaft 110 that is axially close to the second rotating shaft 120 .

[0049] The first compressor 210 is selected from one or more of a centrifugal compressor, an axial flow compressor, and a diagonal flow compressor. The first compressor 210 can be a single-stage centrifugal compressor, a multi-stage axial flow compressor (e.g., 3-stage or 4-stage), a multi-stage diagonal flow compressor (e.g., 3-stage), or a combination of a centrifugal compressor, an axial flow compressor, and a diagonal flow compressor. In some embodiments, the first compressor 210 can include a compressor impeller and a diffuser. The air intake end of the first compressor 210 is connected to the external environment for air intake.

[0050] The second compressor 220 is mounted on the end of the second rotating shaft 120 axially away from the first rotating shaft 110 , and the second turbine 320 and the third turbine 330 are mounted in sequence on the end of the second rotating shaft 120 axially close to the first rotating shaft 110 .

[0051] The second compressor 220 may be a centrifugal compressor. In some embodiments, the second compressor 220 may include a compressor impeller and a diffuser. The intake end of the second compressor 220 is connected to the exhaust end of the first compressor 210, and the exhaust end of the second compressor 220 is connected to the intake end of the combustion chamber 400. The first compressor 210 and the second compressor 220 are connected in series. After being compressed by the first compressor 210, the external ambient gas (such as air) enters the second compressor 220 for further compression to increase the final pressure of the gas leaving the above-mentioned compressor combination. The combined pressure ratio of the first compressor 210 and the second compressor 220 connected in series in the above-mentioned manner is greater than the pressure ratio of the first compressor 210 or the second compressor 220 alone. The pressure ratio of the first compressor 210 can be selected from 2 to 5, and the pressure ratio of the second compressor 220 can be selected from 5 to 10. For example, if the pressure ratio of the first compressor 210 is 5 and the pressure ratio of the second compressor 220 is 5, the pressure ratio after the series connection is 25; if the pressure ratio of the first compressor 210 is 3 and the pressure ratio of the second compressor 220 is 8, the pressure ratio after the series connection is 24; if the pressure ratio of the first compressor 210 is 4 and the pressure ratio of the second compressor 220 is 7, the pressure ratio after the series connection is 28. In some optional embodiments, the pressure ratio of the second compressor 220 is greater than or equal to the pressure ratio of the first compressor 210.

[0052] The combustion chamber 400 can be an annular combustion chamber, a single-tube combustion chamber, an annular tube combustion chamber, or the like. If the combustion chamber 400 is an annular combustion chamber, it can be disposed about the second rotating shaft 120. The exhaust port of the combustion chamber 400 is connected to the inlet port of the third turbine 330. Axially, the second turbine 320 is located between the first turbine 310 and the third turbine 330. The combustion gas from the exhaust port of the combustion chamber 400 passes through the third turbine 330, the second turbine 320, and the first turbine 310 in sequence before being discharged.

[0053] The third turbine 330 is a film-cooled turbine having a hollow structure.

[0054] According to the gas turbine of this embodiment of the present invention, by installing a first compressor 210 on a first rotating shaft 110 and a second compressor 220 on a second rotating shaft 120, with the intake end of the second compressor 220 connected to the exhaust end of the first compressor 210, the pressure ratio of the compressors connected in series is increased, which is beneficial for improving the efficiency of the gas turbine. Furthermore, by configuring the third turbine 330, which is connected to the exhaust end of the combustion chamber 400, as a hollow film-cooled turbine, the cooling film protects the turbine 330, further increasing the temperature of the gas flowing into the turbine, thereby improving the efficiency of the gas turbine. Furthermore, by arranging the first turbine 310, the second turbine 320, and the third turbine 330 on the first rotating shaft 110 and the second rotating shaft 120, the high-temperature gas can be more fully utilized, thereby improving the overall efficiency of the gas turbine.

[0055] Further, if Figure 2 As shown, Figure 2 for Figure 1 A partial schematic diagram of an embodiment of the third turbine, Figure 2 The third turbine 330 is exemplarily shown as a hollow turbine, and the third turbine 330 includes a turbine shell 333 and a turbine inner cavity 334 surrounded by the turbine shell 333. A turbine air film hole 332 is provided on the turbine shell 333, and the turbine air film hole 332 is connected to the turbine inner cavity 334. The hollow turbine shell 333 can be formed by two or more shell parts fixedly connected (for example, welded). In other embodiments, the turbine inner cavity 334 can also be a connecting channel to supply air to the turbine air film hole 332. In other embodiments, a baffle, a baffle column or a labyrinth structure can be provided in the turbine inner cavity 334 to increase the cooling effect inside the turbine, so as to further improve the overall cooling effect of the third turbine 330.

[0056] like Figure 3 As shown, Figure 3 for Figure 1A partial schematic diagram of another embodiment of the third turbine in FIG. There are multiple turbine film holes 332, and the turbine film holes 332 can be located at the leading edge and blade tip of the turbine 330. The multiple turbine film holes 332 located at the leading edge of the blade can be arranged radially along the turbine 330. The turbine film holes 332 are located at different positions to meet the cooling needs of each position and to finely control the formation of the cooling film. The turbine film holes 332 located at the blade tip can be reused as bearing nozzles at the turbine. On the one hand, the turbine film holes 332 located at the blade tip are used for cooling at the blade tip. On the other hand, radial gas thrust can be formed between the blade tip with the turbine film holes 332 and the external casing. The pressurized gas ejected from the turbine film holes 332 at the blade tip can radially support the turbine 330 to a certain extent, which is beneficial to improving the rotational stability of the rotor system.

[0057] like Figure 4 As shown, Figure 4 for Figure 1 A partial schematic diagram of another embodiment of the third turbine is shown in FIG. 3 . The turbine air film hole 332 can also be located at the trailing edge of the blade of the turbine 330 , and the air outlet from the trailing edge is beneficial to the airflow diversion.

[0058] Further, if Figure 5 As shown, Figure 5 for Figure 1 A partial schematic diagram of an embodiment of the second rotating shaft in FIG. The second rotating shaft 120 has a shaft connecting hole 123 at a position corresponding to the third turbine 330, so as to provide cooling air to the third turbine 330 through the shaft connecting hole 123 inside the second rotating shaft 120. In addition, at least one axial end of the second rotating shaft 120 has an inner shaft bearing cavity 122. Figure 1 The inner shaft bearing cavity 122 is shown as being located at an end axially away from the first rotating shaft 110. In other embodiments, the inner shaft bearing cavity 122 may also be located at an end axially closer to the first rotating shaft 110. The inner shaft bearing cavity 122 communicates with the shaft connecting hole 123 via an inner shaft air passage 124. The shaft connecting hole 123 communicates with the turbine inner cavity 334 via the turbine connecting hole 331 of the third turbine 330. In this way, cooling air from the outside first enters the inner shaft bearing cavity 122, then passes through the inner shaft air passage 124 and the shaft connecting hole 123 into the turbine inner cavity 334, and is then ejected through the turbine air film holes 332 to form a cooling air film on the outer wall of the third turbine 330.

[0059] Because the third turbine 330 is located near the exhaust end of the combustion chamber 400, the exhaust from the combustion chamber 400 reaches its highest temperature at location (R1) before the third turbine 330. The temperature decreases after passing through the third turbine 330 at location (R2), and further decreases after passing through the second turbine 320 at location (R3). Finally, the exhaust reaches a residual heat temperature after passing through the first turbine 310 at location (R4). At this point, the residual heat can be directly discharged into the atmosphere or directed to other external components for further utilization. Therefore, of the first, second, and third turbines 310, 320, 330, the third turbine 330 has the highest temperature before the turbine. Therefore, the third turbine 330 utilizes a hollow film-cooled turbine to improve cooling efficiency. Accordingly, the second turbine 320 can also utilize a hollow film-cooled turbine to improve cooling efficiency. Alternatively, if the temperature before the turbine is within the tolerance of the turbine material, the second turbine 320 can be a conventional solid turbine. The first turbine 310 can generally be a conventional solid turbine.

[0060] Further, continue as Figure 1 As shown, at least one axial end of the second rotating shaft 120 is provided with an at least partially built-in inner air bearing 510 , and the inner air bearing 510 has an air supply channel, which supplies cooling air to the third turbine 330 through the interior of the second rotating shaft 120 .

[0061] Specifically, the inner air bearing 510 is a stator component relative to the second rotating shaft 120. The inner air bearing 510 can be connected to the gas turbine's casing or bearing seat, for example. The inner air bearing 510 at least partially extends into the shaft's inner bearing cavity 122. The portion of the inner air bearing 510 extending into the shaft's inner bearing cavity 122 forms an air film gap with the circumferential inner wall of the shaft's inner bearing cavity 122. The inner air bearing 510 supports the rotation of the second rotating shaft 120 and is located at one end of the second rotating shaft 120 to at least partially close the opening of the shaft's inner bearing cavity 122. The remaining gap is sealed by an air film formed during operation of the inner air bearing 510. The inner air bearing 510 has an air supply channel 511 connected to the shaft's inner bearing cavity 122 to provide turbine cooling air to the shaft's inner bearing cavity 122.

[0062] Further, if Figure 6 As shown, Figure 6 for Figure 1 A partial schematic diagram of an embodiment of an inner air bearing shows that the inner air bearing 510 has a plurality of radially extending and circumferentially arranged first air holes 512. The air inlets of the first air holes 512 are connected to an air source, and the air outlets of the first air holes 512 face the circumferential wall of the inner shaft bearing cavity 122. The air source can be an external air source, such as an air pump. Alternatively, the air source can be the second compressor 220, for example, with the air inlets of the first air holes 512 connected to the exhaust port of the second compressor 220. Figure 6As shown in the figure, the air inlet of the first air hole 512 is connected to the air supply channel 511, and the air supply channel 511 is connected to the air source. In other optional embodiments, the air inlet of the first air hole 512 can also be connected to the air source through other channels.

[0063] Specifically, the axial position of each first air hole 512 is located between the external opening of the inner bearing cavity 122 and the air outlet of the air supply channel 511, so that the air outlet of the air supply channel 511 is inside the inner bearing cavity 122 and can achieve air sealing through each first air hole 512.

[0064] During the operation of the gas turbine, the first air hole 512 sprays air toward the circumferential wall of the shaft bearing cavity 122 to form an air film. The air film supports the rotation of the second rotating shaft 120 and forms an air seal between the second rotating shaft 120 and the inner air bearing 510, so that the turbine cooling air provided by the air supply channel 511 of the inner air bearing 510 to the shaft bearing cavity 122 is leaked as little as possible to ensure the cooling effect.

[0065] In some optional embodiments, the first air hole 512 is a stepped hole, with the larger end of the stepped hole facing the inner air bearing 510. The stepped hole can further increase the velocity of the incoming air flow to further enhance the strength of the air film.

[0066] In some optional embodiments, the first air holes 512 are arranged in two or more circles along the axial direction to increase the air output, ensure the strength of the air film, and increase the stability of the inner air bearing 510.

[0067] In some optional embodiments, such as Figure 7 As shown, Figure 7 for Figure 1 A partial schematic diagram of another embodiment of a central air bearing shows that the air supply channel 511 has an enlarged diameter flare 513 corresponding to its outlet, and the first air hole 512 is formed corresponding to the flare 513. The larger diameter of the flare 513 compared to the original air supply channel 511 facilitates machining tools (such as hook cutters) to penetrate the flare 513 to machine the larger end of the first air hole 512. The smaller end of the first air hole 512 can then be machined, for example, by laser drilling.

[0068] Furthermore, the gas pressure provided by the air supply channel 511 is greater than the turbine pre-pressure of the third turbine 330, which can ensure that the cooling gas can withstand the turbine pre-pressure and be ejected through the turbine film hole 332 to form a cooling air film.

[0069] Specifically, the air inlet of the air supply passage 511 is connected to the exhaust end of the second compressor 220 , and the exhaust end pressure of the second compressor 220 is greater than the turbine pre-turbine pressure of the third turbine 330 .

[0070] Further, continue as Figure 1As shown, the gas turbine further includes a first stator vane assembly 710, which is located between the third turbine 330 and the exhaust end of the combustion chamber 400 and is disposed proximate to the third turbine 330. The stators in the first stator vane assembly 710 are fluid-cooled vanes with a hollow structure, which improve the cooling effect of the first stator vane assembly 710 and facilitate raising the exhaust end temperature of the combustion chamber 400. The fluid-cooled vanes can be air film cooled vanes or liquid film cooled vanes, or vanes having internal cooling channels for gas or liquid circulation.

[0071] Further, if Figure 8 As shown, Figure 8 for Figure 1 A partial schematic diagram of another embodiment of the third turbine in FIG. A first guide vane assembly 710 includes a first support 711, a second support 713, and a blade assembly 712 with an axial air passage located between the two supports. Turbine 330 also includes a turbine thrust nozzle 335. The outlet of turbine thrust nozzle 335 faces the wall surface of first support 711 of first guide vane assembly 710. The pressurized gas ejected from turbine thrust nozzle 335 can generate axial thrust, which is beneficial to the axial balance of the gas turbine's rotor system. Furthermore, sealing holes 336 can be provided on both sides of turbine thrust nozzle 335. The diameter of sealing holes 336 is smaller than that of turbine thrust nozzle 335. The pressurized gas ejected from sealing holes 336 can form an air curtain seal to seal the gas from turbine thrust nozzle 335 as much as possible to increase thrust.

[0072] Further, if Figure 9 As shown, Figure 9 FIG2 is a schematic structural diagram of a gas turbine according to another embodiment of the present invention. The second turbine 320 may also be a film-cooled turbine with a hollow structure. The specific structure thereof may be substantially the same as that of the third turbine 330.

[0073] Further, if Figure 9 As shown, the gas turbine further includes a second guide vane assembly 720, which is located between the third turbine 330 and the second turbine 320 and disposed proximate to the second turbine 320. The guide vanes in the second guide vane assembly 720 are hollow, fluid-cooled blades. The specific structure of the second guide vane assembly 720 may be substantially the same as that of the first guide vane assembly 710.

[0074] Further, continue as Figure 1As shown, the gas turbine further includes a first motor 910 and a second motor 920. The first motor 910 is mounted on the first shaft 110 and is located between the first compressor 210 and the first turbine 310, or on the side of the first compressor 210 facing away from the first turbine 310. Because the temperature between the second compressor 220 and the third turbine 330 is very high, which can reduce motor efficiency, the second motor 920 can be mounted on the second shaft 120 and located on the side of the second compressor 220 facing away from the third turbine 330.

[0075] The power of the first motor 910 is greater than or equal to the power of the second motor 920. It should be understood that the sizes and proportions of the first motor 910 and the second motor 920 shown in the figures do not represent their actual sizes and proportions, nor do they indicate the magnitude and comparison of power.

[0076] Furthermore, the first motor 910 and / or the second motor 920 can be superconducting motors, which can reduce the size of the motors and achieve higher motor efficiency (even 100%). Superconducting motors can also provide high power (hundreds of kilowatts or megawatts) and can be used in high-power gas turbines. In this embodiment, the gas turbine's fuel is reused as the coolant for the superconducting motor, and the fuel can be liquefied hydrogen, liquefied natural gas, etc.

[0077] Further, if Figure 10 and 11 As shown, Figure 10 is a schematic structural diagram of a gas turbine according to yet another embodiment of the present invention. Figure 11 for Figure 10 A schematic structural diagram of an embodiment of a second rotating shaft is shown. The second rotating shaft 120 includes a first shaft segment 121 and a second shaft segment 125 arranged axially in sequence. The first and second shaft segments 121, 125 are connected by a coupling 128. The coupling 128 includes an air seal cavity 129 that connects the air paths of the first and second shaft segments 121, 125. A second motor 920 is mounted on the second shaft segment 125. In embodiments where the gas turbine includes an inner air bearing 510, the inner air bearing 510 is located at the end of the second shaft segment 125 axially distal from the first shaft segment 121. This arrangement prevents the second rotating shaft 120 from being excessively long, which would make machining and adjusting rotor dynamic parameters difficult. After the first and second shaft segments 121, 125 are connected by the coupling 128, the size and power of the second motor 920 can be increased as needed to ensure power balance and coordination between the first and second motors 910, 920.

[0078] Specifically, such as Figure 11 For ease of display, Figure 11 The ratio of the first shaft section 121 to the second shaft section 125 is compared Figure 10The first shaft section 121 has a shaft communication hole 123 and an internal shaft air path 124. The second shaft section 125 has an internal shaft air path 126 and an internal shaft bearing cavity 122. A coupling 128 is airtightly connected to the first and second shaft sections 121, 125 and has an air seal cavity 129. The air seal cavity 129, together with the internal shaft air paths 124 and 126, forms the internal shaft air path of the second rotating shaft 120.

[0079] Further, if Figure 12 As shown, Figure 12 This is a schematic structural diagram of a gas turbine according to another embodiment of the present invention. A nose cone 126 is provided at one end of the second rotating shaft 120, where the inner air bearing 510 is provided. The inner air bearing 510 has a nose cone air supply hole. The nose cone 126 can be integrally formed with the second rotating shaft 120, or can be fixedly mounted on the second rotating shaft 120 by methods such as welding or connecting parts. The end of the nose cone 126 axially facing the inner air bearing 510 has a thrust surface. The inner air bearing 510 has a nose cone air supply hole. The air inlet end of the nose cone air supply hole can be connected to the air supply channel 511, and the air outlet of the nose cone air supply hole faces the thrust surface of the nose cone 126. The pressurized air ejected from the nose cone air supply hole can impart axial thrust to the nose cone 126, which is beneficial for axial force balance of the rotor system. In other embodiments, the air inlet end of the nose cone air supply hole can also be connected to an air source through other channels. In some embodiments, a thrust bearing can be provided on the side of the nose cone 126 away from the inner air bearing 510.

[0080] Furthermore, a thrust plate is provided on the first rotating shaft 110 and / or the second rotating shaft 120 , and thrust bearings may be provided on both axial sides of the thrust plate.

[0081] Further, if Figure 1 , 9, 10, and 12, the gas turbine further includes a plurality of first radial bearings 520, which are external radial air bearings sleeved on the outer circumference of the first rotating shaft 110 and / or the second rotating shaft 120. The first radial bearings 520 may be positioned at one or more of the positions shown in the above figures, or at other axial positions not shown.

[0082] Further, if Figure 13 As shown, Figure 13 is a schematic structural diagram of a gas turbine according to yet another embodiment of the present invention. Figure 13 An example is shown in which the inner air bearing 510 is located at an end of the second rotating shaft 120 that is axially close to the first rotating shaft 110 .

[0083] Further, if Figure 14 As shown, Figure 14This is a schematic diagram of the structure of a gas turbine according to yet another embodiment of the present invention. The gas turbine also includes a regenerator (HR) to further improve the efficiency of the gas turbine. Specifically, the regenerator (HR) includes a first passage and a second passage for heat exchange. The exhaust end of the second compressor 220 is connected to the intake end of the first passage, the intake end of the combustion chamber 400 is connected to the exhaust end of the first passage, and the exhaust end of the first turbine 310 is connected to the intake end of the second passage. The exhaust end of the second passage is connected to the atmosphere or other external components.

[0084] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0085] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0086] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0087] While the embodiments of the present invention are described above, these embodiments do not exhaustively describe all details and do not limit the invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the above description. These embodiments are selected and described in detail in this specification in order to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better utilize the invention and its modifications. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A gas turbine, characterized in that: The invention comprises a first rotating shaft and a second rotating shaft arranged in sequence along the axial direction, and a combustion chamber, wherein a first compressor is installed at one end of the first rotating shaft axially away from the second rotating shaft, and a first turbine is installed at one end of the second rotating shaft axially close to the second rotating shaft, a second compressor is installed at one end of the second rotating shaft axially away from the first rotating shaft, and a second turbine and a third turbine are installed in sequence along the axial direction close to the first rotating shaft, an intake end of the second compressor is connected to an exhaust end of the first compressor, an exhaust end of the second compressor is connected to an intake end of the combustion chamber, an exhaust end of the combustion chamber is connected to an inlet end of the third turbine, and the third turbine is a hollow The gas turbine further comprises a film-cooled turbine having an air-film cooling structure, wherein at least one axial end of the second shaft is provided with an at least partially built-in inner air bearing, wherein the inner air bearing has an air supply passage, wherein the air supply passage supplies cooling air to the third turbine through the interior of the second shaft, wherein the gas turbine further comprises a regenerator HR, wherein the regenerator HR comprises a first passage and a second passage capable of heat exchange, wherein the exhaust end of the second compressor is connected to the intake end of the first passage, the intake end of the combustion chamber is connected to the exhaust end of the first passage, the exhaust end of the first turbine is connected to the intake end of the second passage, and the exhaust end of the second passage is connected to the external atmosphere or other external components.

2. The gas turbine according to claim 1, characterized in that The end of the second rotating shaft provided with the inner air bearing has a nose cone, and the inner air bearing has a nose cone air supply hole; and / or, The gas turbine further includes a plurality of first radial bearings, wherein the first radial bearings are external radial air bearings sleeved on the outer circumferential surface of the first rotating shaft and / or the second rotating shaft.

3. The gas turbine according to claim 1, characterized in that In the axial direction, the second turbine is located between the first turbine and the third turbine, and the combustion gas from the exhaust end of the combustion chamber passes through the third turbine, the second turbine and the first turbine in sequence and is then discharged; and / or, The gas turbine further comprises a first stationary blade assembly, which is located between the third turbine and the exhaust end of the combustion chamber and is arranged close to the third turbine, and the stationary blades in the first stationary blade assembly are fluid-cooled blades with a hollow structure.

4. The gas turbine according to claim 1, characterized in that The second turbine is a film-cooled turbine having a hollow structure; and / or, The gas turbine further includes a second stationary blade assembly, which is located between the third turbine and the second turbine and is arranged close to the second turbine. The stationary blades in the second stationary blade assembly are fluid-cooled blades with a hollow structure.

5. The gas turbine according to claim 1, characterized in that The gas turbine also includes a first electric machine and a second electric machine, The first motor is mounted on the first rotating shaft and is located between the first compressor and the first turbine, or is located on a side of the first compressor away from the first turbine; The second motor is mounted on the second rotating shaft and is located on a side of the second compressor away from the third turbine; The power of the first motor is greater than or equal to the power of the second motor.

6. The gas turbine according to claim 5, characterized in that The second rotating shaft comprises a first shaft section and a second shaft section arranged in sequence along the axial direction, the first shaft section and the second shaft section are connected via a coupling, and the coupling has an air sealing cavity connecting the air paths in the first shaft section and the second shaft section; The second motor is mounted on the second shaft section; The gas turbine includes an inner air bearing located at an end of the second shaft segment axially away from the first shaft segment.

7. The gas turbine according to claim 6, characterized in that The first electric machine and / or the second electric machine is a superconducting electric machine, and the fuel of the gas turbine is reused as a coolant for the superconducting electric machine.

8. The gas turbine according to claim 1, characterized in that The pressure ratio of the second compressor is greater than or equal to the pressure ratio of the first compressor; The second compressor is a centrifugal compressor; The first compressor is selected from one or more of a centrifugal compressor, an axial flow compressor, and a diagonal flow compressor.

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