Rotor, power generation turbine comprising said rotor and thermodynamic circuit using said turbine

Abstract

Disclosed herein is a rotor including a set of rotor discs. Each rotor disc includes a respective annular row of rotor blades. The rotor also includes a front shaft portion and a rear shaft portion. A first set of rotor discs is integrally formed with a section of one of the front shaft portion and the rear shaft portion. The section of the shaft portion and the first set of rotor discs form a unitary component. In addition, the front axle portion and the rear axle portion are connected to each other by a tie rod device.

Description

[0001] manual Technical Field

[0002] This disclosure relates to gas expanders particularly suitable for oxygen-fueled power cycles (e.g., CO2 cycles, such as the Allam cycle, also known as the NET power cycle) operated under high pressure with process gases. More generally, this disclosure relates to rotors for power generation turbines and turbines including said rotors. Background Technology

[0003] Fossil fuels are the primary source of chemical energy used to generate mechanical power. Fossil fuels are mixed with air and burned to produce high-pressure, high-temperature combustion gases, which expand in a turbine or expander. The expander converts the enthalpy of the combustion gases into mechanical power that can be obtained on the expander's output shaft and used to drive loads, such as compressors or compressor units, or to rotate generators and convert mechanical power into electricity.

[0004] One of the main concerns regarding the burning of fossil fuels involves the production of carbon dioxide, a greenhouse gas that is considered one of the main causes of global warming and climate change.

[0005] To reduce the environmental impact of power generation through the combustion of fossil fuels, post-combustion carbon dioxide (CO2) capture options have been investigated. CO2 capture facilities have been developed to treat flue gas from gas turbines and remove CO2 from it before it is released into the environment. However, CO2 capture facilities are costly in terms of both CAPEX and the energy required to operate them, which reduces the overall thermodynamic efficiency of the system. The percentage of CO2 in the flue gas is also low. This necessitates processing large volumes of flue gas through CO2 capture facilities, making the capture process particularly inefficient.

[0006] In recent years, the oxy-fuel cycle (also known as the oxy-fuel cycle) has been developed, in which fuel (such as natural gas or another fossil fuel) is blended under high pressure into a mixture of oxidant consisting primarily of oxygen (O2) and carbon dioxide (CO2). The blend of fuel, oxygen, and carbon dioxide is burned in the burner of an expander, producing pressurized flue gas consisting only or almost entirely of carbon dioxide and water.

[0007] The flue gas expands in the expander to generate mechanical power. The exhaust gas emitted from the expander's exhaust side is cooled in a regenerative heat exchanger and further quenched into condensate, which can then be removed from the quenched flue gas. The low-temperature flue gas, mainly or solely composed of carbon dioxide, is pressurized and recirculated through the regenerative heat exchanger toward the expander's burner.

[0008] The oxygen supplied to the expander's burner can be obtained by separating from ambient air and removing nitrogen, so that the working fluid supplied to the burner consists primarily of oxygen and carbon dioxide, and excludes nitrogen. The generated flue gas consists primarily of water and carbon dioxide. Water is removed from the flue gas through condensation, and the portion of anhydrous flue gas that is not recirculated to the burner can be effectively treated in the carbon dioxide capture unit.

[0009] The oxygen-fuel cycle described above is a semi-closed cycle because only a small portion of the flue gas leaves the cycle after water has been removed from it.

[0010] Oxygen-fueled or oxygen-combustion cycles (such as those described above) are of particular interest in terms of efficiency and reduction of harmful emissions. However, oxygen-fueled or oxygen-combustion cycles operate under supercritical CO2 conditions at the expander inlet and are characterized by a high pressure drop across the expander and a high torque applied to the expander rotor. These factors become critical as the expander's rated power increases, posing significant challenges to expander rotor design and potentially limiting the expander's maximum power ratio.

[0011] Novel rotor and turbine designs suitable for achieving higher power ratios, for example, in an oxygen fuel cycle, will be welcomed in the field. Summary of the Invention

[0012] According to one aspect, this document discloses a rotor for a power generation turbine, such as, particularly, a rotor for an expander or a turbine expander. In some embodiments, the expander is an oxy-fuel combustion expander adapted, for example, to process supercritical carbon dioxide at the expander inlet.

[0013] In the embodiments disclosed herein, the rotor includes a set of rotor disks, and each rotor disk includes a corresponding annular row of rotor blades. The rotor blades may be integrally formed with the respective rotor disks, or may be manufactured as separate components subsequently mounted on the rotor disks. The rotor also includes a front shaft portion and a rear shaft portion. The first set of rotor disks is integrally formed with a section of the front shaft portion. The section of the front shaft portion and the first set of rotor disks form an integral component. Furthermore, the front shaft portion and the rear shaft portion are connected to each other by a tie rod arrangement. The first set of rotor disks may include one or more rotor disks.

[0014] An additional set of rotor disks may be integrally formed with the other of the front shaft portion and the rear shaft portion. The other of the front shaft portion and the rear shaft portion, along with the additional set of rotor disks, then form an integral component. The additional set of rotor disks may include one rotor disk or multiple rotor disks.

[0015] In some embodiments, the rotor may include at least one additional rotor disk positioned between the front axle portion and the rear axle portion, and preferably includes multiple additional rotor disks. The front axle portion, the additional rotor disks, and the rear axle portion are stacked on top of each other and connected to each other by a tie rod arrangement.

[0016] In some embodiments, the first set of rotor disks is integrally formed with the front shaft portion, and multiple additional rotor disks are positioned between the front shaft portion and the rear shaft portion. The front shaft portion, the multiple rotor disks, and the rear shaft portion are stacked on top of each other and connected to each other by a tie rod device.

[0017] According to another aspect, this document discloses a power generation turbine, such as an expander, which includes a rotor as outlined above and described in more detail below. In the embodiments disclosed herein, the turbine is an expander, and may be a supercritical CO2 expander, i.e., an expander in which carbon dioxide is under supercritical conditions at the inlet of the expansion flow path, and / or an expander for an oxygen-fuel combustion cycle (such as the Allam cycle).

[0018] Additional features of the rotor and turbine are set forth in the dependent claims. Attached Figure Description

[0019] Now, please briefly refer to the attached diagram, in which:

[0020] Figure 1 This is a schematic diagram of an oxygen fuel power circuit;

[0021] Figure 2 This is a cross-sectional view of an expander in one implementation scheme; and

[0022] Figure 3 It is another implementation scheme for use Figure 2 A cross-sectional view of a portion of the rotor of an expander. Detailed Implementation

[0023] Figure 1 The schematic diagram illustrates a simplified supercritical carbon dioxide cycle (sCO2 cycle for short), such as the Allam cycle or a similar oxygen-fuel combustion cycle, in which the use of an expander including a rotor according to this disclosure may be particularly advantageous. Generally, as understood herein, a supercritical carbon dioxide cycle is a cycle in which carbon dioxide is under supercritical conditions at least at the inlet of the expansion flow path in the expander.

[0024] Figure 1The power system 1 shown includes an expander (also known as a turboexpander) 3, which includes an expansion section 5 and a burner 7. For example, the burner 7 can be an annular burner, a canister burner, a canister-annular burner, etc. In the currently preferred embodiment, the burner is a canister burner, which includes multiple combustion chambers arranged around the rotation axis of the expander 3, such as... Figure 2 This is shown in more detail below. In some implementations, such as... Figure 1 As schematically shown, the combustion chamber is housed within the high-pressure casing of the expander. In some embodiments, each combustion chamber is housed in a corresponding support formed within the high-pressure casing of the expander, as will be described in more detail below.

[0025] Figure 2 Reference numeral 7.1 in the figures indicates a single combustion chamber of a can-type burner or a can-annular burner. In other embodiments not shown, the burner may be an annular burner, as mentioned.

[0026] The burner 7 is supplied with an oxidant stream from an oxidant source. The oxidant can be oxygen (O2) or a mixture containing oxygen and carbon dioxide (CO2) or primarily composed of oxygen and carbon dioxide. The oxidant stream can be generated by an air separation unit 9, which is characterized by the oxidant source. The air separation unit 9 removes nitrogen or nitrogen and carbon dioxide from ambient air to generate the desired oxidant stream, which is supplied to the burner 7 of the expander 3 via an oxidant line 11. In some embodiments, for easier handling of the oxidant stream, the oxidant stream may contain approximately 20% by volume oxygen and 80% by volume carbon dioxide. The percentages of CO2 and O2 mentioned above are exemplary. Carbon dioxide can be added to the oxygen via a recirculation line 12, as explained in more detail below.

[0027] Reference numeral 13 indicates a fuel supply line adapted, for example, to supply natural gas (such as methane) to burner 7, specifically to each of its combustion chambers 7.1. Oxidant and fuel are supplied to burner 7 at high pressure at the inlet side of expander 3. The upper pressure of the thermodynamic cycle can be, for example, 50 barA or higher, preferably 100 barA or higher, for example about or higher than 200 barA, preferably about or higher than 250 barA or higher, for example equal to or higher than 300 barA. Generally, the pressure can be below 800 barA or below 650 barA. In some embodiments, the upper pressure of the thermodynamic cycle, i.e., the pressure in the burner and at the first expansion stage, can be 100 barA, 150 barA, 200 barA, 250 barA, 300 barA, or 350 barA.

[0028] The oxidizer-fuel mixture is burned in burner 7. The pressurized hot combustion gas generated by the combustion expands in expansion section 5 of expander 3. For example, the temperature at the outlet side of the fixed nozzle downstream of the burner (i.e., at the inlet of the expander rotor) can be between 800°C and 1500°C.

[0029] The exhaust gas expands at the exhaust side of the expander 3 and is then discharged into the exhaust line 15. The exhaust gas in the exhaust line 15 may be at a temperature between about 400°C and about 700°C, for example, about 600°C, and at a pressure between about 10 barA and about 100 barA, preferably between about 20 barA and about 60 barA.

[0030] The circuit also includes a regenerative heat exchanger 17, through which hot flue gas flowing through the hot side 17.1 is cooled by heat exchange with quenched flue gas flowing through the cold side 17.2 of the regenerative heat exchanger 17. Flue gas discharged from the hot side 17.1 of the regenerative heat exchanger 17 is further quenched in a quench heat exchanger 19 to a temperature at which the vapor contained in the discharged flue gas condenses. Condensate is removed from the discharged flue gas in a water / gas separator 21.

[0031] The dehydrated and chilled flue gas, mainly or solely composed of carbon dioxide, is compressed in the flue gas compressor 23 to the pressure at the inlet side of the expander 3. Although in Figure 1 In the schematic diagram, flue gas compressor 23 is illustrated as a single compressor, but in some embodiments, multiple compressors may be used. For example, flue gas compressor 23 may be a multi-stage compressor or a compressor unit. In some embodiments, the compressor may be an intercooled compressor. In some embodiments, the main compressor may be connected in series with two sequentially arranged pumps.

[0032] Compressed flue gas delivered by flue gas compressor 23 is partially removed from the circulation via discharge line 25. If compressor 23 is characterized by multiple turbines arranged in series, discharge line 25 may be connected, for example, between two sequentially arranged turbines and / or at the discharge side of the downstream turbine.

[0033] The main portion of the compressed flue gas is conveyed through the cold side 17.2 of the regenerative heat exchanger 17 and heated by heat exchange with the hot flue gas flowing through the hot side 17.1 of the regenerative heat exchanger 17, and then recirculated to the expander 3 via the recirculation line 25. The recirculated flue gas through the recirculation line 25 is mixed with the combustion gases generated in the burner 7 and / or with the oxidant stream from the oxidant line 11.

[0034] In some implementations, the quench flue gas is delivered via a side flow through a cooling line 27 toward the components of the expander 3 that require cooling, bypassing the regenerative heat exchanger 17.

[0035] The expander 3 may include an output shaft end 31, which may be integral with the central portion of the rotor, or assembled with the central portion of the rotor via bolted connection, welding, Hirth or spline connection, or a combination thereof. The mechanical power generated by the expansion of the combustion gas in the expansion section 5 of the expander 3 can be used on the output shaft end 31 for mechanical drive or power generation purposes. Figure 1 In an exemplary embodiment, the output shaft end 31 is directly or driveably connected to the generator 33 via a gearbox, connector, or a combination thereof. The flange connection between the output shaft end 31 and the generator 33 is... Figure 2 As shown in Figure 49. Generator 33 is then electrically connected to power distribution network 35. Figure 1 and Figure 2 In the diagram, the output shaft end 31 is shown as being located at the rear of the expander 3. In other embodiments not shown, the output shaft end 31 may be located at the front of the expander. In yet another embodiment not shown, two output shaft ends may be provided, one at the front of the expander and one at the rear.

[0036] As used herein, "front" and "rear" refer to the flow direction of the process gas through the expander 3. Therefore, "front" indicates the position on the burner 7 side, and "rear" indicates the position on the side opposite to the burner 7 (i.e., the discharge side of the expander 3).

[0037] The high pressure drop across expander 3, the high absolute pressure in burner 7 and the expander's cooling ducts, and the high torque applied to the expander shaft pose significant challenges to the design of expander 3, particularly for high rated power, such as around or above 100MW, e.g., between 100MW and 2000MW. Expanders (and specifically, the rotor designs disclosed herein) can be used to achieve high power ratios, preferably above 50MW, e.g., about 100MW or higher, e.g., 150MW or higher, e.g., 200MW or higher, or 300MW or higher. In embodiments, the rated power may be below 2000MW, preferably below 1500MW, e.g., below 1000MW, or below 800MW. For example, the rated power may be contained between 200MW and 650MW. The intermediate values ​​of the upper and lower limits of each of the above ranges are also explicitly disclosed herein.

[0038] Continue to refer to Figure 1 , Figure 2 A cross-sectional view of an expander 3 in one embodiment is shown.

[0039] In some embodiments, the expander 3 includes an outer housing 41 that houses the burner 7. In some embodiments, the outer housing 41 includes a body 41.1 (referred to herein as the high-pressure housing) and a closure 41.2 (referred herein as the low-pressure exhaust housing). The high-pressure housing 41.1 may include a body, which may be integral, i.e., may consist of a single piece manufactured, for example, by forging, machining, casting, or a combination thereof. In some embodiments, the high-pressure housing 41.1 may be manufactured by welding multiple components together, which preferably intersect along a plane orthogonal to the axis of rotation.

[0040] The low-pressure exhaust housing 41.2 can be positioned on the exhaust side (i.e., rear side) of the expander 3, specifically on the side opposite the burner 7. The low-pressure exhaust housing 41.2 can be integral, i.e., it can consist of a single piece manufactured, for example, by forging, machining, casting, or a combination thereof. In some embodiments, the low-pressure exhaust housing 41.2 can be manufactured as two or more components, which can be irreversibly connected to each other, for example, by welding, or reversibly connected, for example, by bolts. For example, the low-pressure exhaust housing 41.2 can be separated into two parts along a plane containing the axis of rotation of the expander.

[0041] The high-pressure housing 41.1 and the low-pressure exhaust housing 41.2 can be connected to each other along a plane P, which is orthogonal to the axis of rotation AA of the rotor 43 supported for rotation in the outer housing 41.

[0042] In some embodiments, the low-pressure exhaust housing 41.2 forms an exhaust volute or exhaust chamber 41.3 through which the exhaust gas is discharged from the expander 3. In some embodiments, the high-pressure housing 41.1 forms a support for a separate combustion chamber 7.1, which together form the burner 7, such as... Figure 2 As shown.

[0043] Reference numerals 45 and 47 indicate bearing arrangements that rotatably support the rotor 43. For example, bearing arrangement 45 on the side opposite the burner 7 (i.e., the rear side) may include an axial or thrust bearing combined with a radial bearing, or a bearing with axial-radial bearing capability. Bearing arrangement 47 on the burner side (i.e., the front side) may include a radial bearing. The opposite arrangement is also possible, where bearings with axial load capability are arranged on the burner side. Bearing arrangements 45 and 47 may be arranged in bearing housings, not shown in detail.

[0044] In some embodiments, the rotor 43 is surrounded by one or more inner housings 51, which are fixedly housed within an outer housing 41. If more than one inner housing is provided, the inner housings may be rigidly connected to each other. Two or more inner housings are arranged sequentially along the axial direction of the expander and together form a single inner housing arrangement.

[0045] Each inner housing 51 can be separated into two parts along a plane parallel to the axis of rotation AA of the rotor 43 (e.g., a plane containing the axis of rotation AA). The arrangement of one or more inner housings 51 located inside the outer housing 41 is particularly advantageous when the combustion gases reach high pressures (approximately 200 barA to 300 barA or higher). The integral high-pressure housing 41.1 can withstand the loads generated by the high pressure inside the outer housing, while the inner housings 51 facilitate the installation of fixed guide vanes or fixed blades as described below.

[0046] The pressure drop across expander 3 can be approximately 150 bar or higher, preferably approximately 200 bar or higher, for example, between 250 bar and 400 bar. To expand the combustion gases generated in burner 7, a large number of expansion stages are preferably employed. Figure 2 In one exemplary embodiment, the expander 3 includes eight stages. In other embodiments, different numbers of expansion stages are foreseeable, preferably equal to or greater than four, more preferably equal to or greater than five. In some embodiments, the number of expansion stages may be greater than eight, for example nine, ten, eleven or more, and preferably less than fifteen. The expansion stages form axial expansion flow paths for the process gas expanded in the expander 3.

[0047] Each expansion stage includes an annular arrangement of fixed guide vanes or fixed blades 53 fixedly arranged in the expander housing 41. Figure 2 In an exemplary embodiment, the annular row of fixed blades is housed within the inner housing 51. Each expansion stage also includes a corresponding annular row of rotor blades 55 arranged downstream of the corresponding annular row of fixed blades along an expansion flow path extending in the longitudinal direction from the combustor 7 to the exhaust chamber 41.3.

[0048] In some embodiments, the first annular row of fixed blades 53.1 may be arranged at the exhaust end of the burner 7 and form a nozzle array that guides hot, high-pressure gas from the combustion chamber 7.1 of the burner 7 to the first row of rotor blades. The first annular row of rotor blades, designated 55.1, may be arranged adjacent to the burner 7 directly downstream of the first annular row of fixed blades 53.1. The last annular row of fixed blades 53.8 may be positioned near the exhaust chamber 41.3, upstream of the last annular row of rotor blades shown at 55.8. Reference numeral 55 generally refers to any annular row of rotor blades or to such rotor blades.

[0049] Rotor blades 55 form part of rotor 43, i.e., are connected to the rotor to rotate with the rotor shaft. In an embodiment, each annular row of rotor blades 55 (i.e., each row 55.i, where i = 1 to 8) is connected to a corresponding rotor disk. The rotor disks are designated as 57.1, 57.2, 57.3, 57.4, 57.5, 57.6, 57.7, and 57.8. Reference numeral 57 indicates a general rotor disk.

[0050] Rotor blades 55 may be manufactured separately from the corresponding rotor disk 57 and mounted on the corresponding rotor disk via suitable connecting means. In other embodiments, rotor blades 55 may be integrally manufactured with the corresponding rotor disk 57, for example, by additive manufacturing. In yet another embodiment, two design options may be combined. One or more stages may include corresponding integrally manufactured components, including rotor blades and disks, and one or more stages may include rotor disks and separately manufactured rotor blades mechanically coupled to the rotor disks.

[0051] exist Figure 2 In the implementation scheme, the first set of rotor disks includes rotor disks 57.1, 57.2, 57.3, and 57.4. The first set of rotor disks 57.1, 57.2, 57.3, and 57.4 are integrally manufactured with the front axle portion 65. More specifically, in Figure 2 In one embodiment, the front axle portion 65 includes a first section 65A and a second section 65B. The rotor disks 57.1, 57.2, 57.3, and 57.4 of the first set of rotor disks are integrally formed with section 65B of the front axle portion 65. For example, the rotor disks 57.1, 57.2, 57.3, and 57.4 and section 65B of the front axle portion 65 may be formed from a single body manufactured by forging, machining, casting, or a combination thereof.

[0052] In other embodiments, the front axle portion 65 may be made of a single, integral body, rather than two sections 65A and 65B. In this case, the entire front axle portion and rotor discs 57.1, 57.2, 57.3, and 57.4 may be manufactured as a single piece.

[0053] The annular rows of rotor blades 55.5, 55.6, and 55.7 are mounted on corresponding auxiliary rotor disks 57.5, 57.6, and 57.7, which are manufactured separately from the front shaft portion 65 and are drivenly coupled to the front shaft portion as described below.

[0054] In some embodiments, an additional set of rotor disks forms a single integral block with the rear shaft portion 67 of rotor 43. As shown, the rear shaft portion 67 may be formed as a single piece. In other embodiments not shown, the rear shaft portion 67 may include two or more segments in the same manner as the front shaft portion 65 and associated segments 65A, 65B.

[0055] exist Figure 2 In one embodiment, the additional set of rotor disks includes a single rotor disk 57.8. In other embodiments not shown, the additional set of rotor disks may include more than one rotor disk.

[0056] In yet another embodiment, not shown, rotor 43 may comprise only a first set of rotor disks integrally formed with the front axle portion 65 or a section thereof and an additional set of rotor disks integrally formed with the rear axle portion 67, without an intermediate disk stacked between the first set of rotor disks and the additional set of rotor disks. Instead, as will be referred to later... Figure 3 As described, the rotor may include a rotor disk integrally manufactured with a section of the front axle portion and an additional single rotor disk disposed between the front axle portion and the rear axle portion, wherein the rear axle portion does not have a rotor disk integrally formed therewith.

[0057] In the implementation plan, such as Figure 2 As shown, the burner 7 extends around the front shaft portion 65. When the burner is a canister burner comprising multiple combustion chambers 7.1 arranged around the axis of rotation of the rotor 43, as... Figure 2 As shown, the combustion chamber can be housed within the high-pressure housing 41.1 around the front axle portion 65. (As indicated...) Figure 2 As shown, each combustion chamber 7.1 can be accommodated in a support integrally formed in the high-pressure housing 41.1, and specifically accommodated in the front side of the high-pressure housing.

[0058] In some embodiments, the emission volute 41.3, formed by the low-pressure emission housing 41.2, extends around the rear axle portion 67.

[0059] The rear axle section 67, the front axle section 65 (specifically, its section 65B), and the intermediate rotor disks 57.5, 57.6, and 57.7 are stacked on top of each other and connected to each other by a tie rod assembly. Figure 2 In an exemplary embodiment, the tie rod device includes a plurality of tie rods 70 arranged around the rotation axis AA of the rotor 43.

[0060] In other embodiments not shown, the tie rod assembly includes a single tie rod coaxial with the rotor (i.e., with the axis of rotation AA).

[0061] In yet another embodiment, the tie rod assembly may include a central tie rod coaxial with the rotation axis AA and a set of tie rods 70 arranged radially around the rotation axis AA at a distance from the rotation axis, such as... Figure 2 As shown.

[0062] In some embodiments, each intermediate rotor disk 57.5, 57.6, 57.7 includes front teeth on each side for torsional engagement with the front teeth of adjacent rotor disks and / or front shaft portion 65 and rear shaft portion 67. The front teeth form a Hirth joint between rotor disks 57.5 and 57.7, between the first intermediate rotor disk 57.5 and the front shaft portion 65, and between the last intermediate rotor disk 57.7 and the rear shaft portion 67.

[0063] The arrangement of the front teeth can facilitate an increase in the torque that can be transmitted from the front shaft portion 65 to rotor discs 57.5, 57.6, and 57.7, from rotor disc 57.7 to the rear shaft portion 67, and between each rotor disc 57.5, 57.6, and 57.7. In some embodiments, the front teeth may be arranged only in some sections of the rotor where the torque to be transmitted is higher, i.e., for example, in the most downstream section of rotor 43. The section where the highest torque needs to be transmitted depends on where the load is applied, i.e., whether it is on the rear side of expander 3 (opposite to burner 7, as in the illustrated embodiment) or on the front side (one side of burner 7). Output shafts on both sides (rear and front) are also foreseeable.

[0064] In some embodiments, the corresponding sealing channels 68 are positioned between each pair of consecutive (i.e., adjacent) rotor disks 57 and are sealed in an annular space radially inside the corresponding fixed blades 53.

[0065] In some embodiments, the expander 3 includes a balancing drum that is drivenly coupled to the rotor 43. Figure 2 In one embodiment, the balance drum 75 is located at the front end of the rotor 43, between the first expander stage and the front bearing arrangement 47, and more specifically on the front axle portion 65.

[0066] In some implementations, the balance drum 75 is integrally formed with the front axle portion 65.

[0067] In the implementation plan, such as Figure 2As shown, the two sections 65A and 65B of the front axle portion 65 can be connected to each other by a plurality of tie rods 77 arranged in a circular pattern around the rotation axis AA of the rotor 43. The tie rods 77 extend through holes provided in two flanges 75.1 and 75.2 of the two sections 65A and 65B of the front axle portion 65. In this embodiment, the flanges 75.1 and 75.2 together form a balance drum 75.

[0068] By separating the balance drum into balance drum parts 75.1 and 75.2, it is easier to manufacture the balance drum, for example, by forging.

[0069] Cooling of rotor 43 is performed by supplying pressurized cooling fluid to cooling conduits formed in rotor 43. Specifically, in some embodiments, compressed and cooled carbon dioxide may be delivered to cooling chamber 81 inside rotor 43. Cooling chamber 81 may be formed inside intermediate rotor disks 57.5, 57.6, 57.7 and may be closed at the rear end and front end by rear shaft portion 57 and front shaft portion 65, respectively.

[0070] For example, the flue gas compressor 23 passes through the cooling line 27 ( Figure 1 The pressurized carbon dioxide supplied can be delivered to the cooling chamber 81 via conduit 83 and can flow through radial holes (not shown) in the rotor 43 to buffer and cool the space 58 between adjacent disks 57. Conduit 83 is fluidly connected to a cooling gas chamber 85 adapted to receive the cooled carbon dioxide. Cooling chamber 81 supplies cooled carbon dioxide to the last five stages of the expander 3. The first three stages of the expander 3 can be cooled via one or more conduits 87 extending parallel to the rotor axis AA and conduit 83 and fluidly connected to the cooling gas chamber 85. Specifically, radial cooling conduits can fluidly connect the cooling chamber to the annular space between rotor disks 57.4 to 57.8, which are radially sealed outward by corresponding sealing channels 68. In addition, radial cooling conduits can fluidly connect each conduit 87 to a corresponding annular space disposed between rotor disks (i.e., rotor disks 57.1, 57.2, 57.3, and 57.4) integrally formed with the front shaft portion 65. These annular spaces are also radially sealed outward by corresponding sealing channels 68.

[0071] In other embodiments not shown, a cooling chamber may be located in the front axle section 65B, and radial conduits may be used to deliver cooling conduits from the cooling chamber toward one or more annular rings of rotor blades integrally formed with the front axle section 65B.

[0072] In some implementations, for example, if the first set of rotor disks manufactured integrally with the front axle section 65B consists of only one or two disks, cooling can be achieved by fluidly connecting the disks to a central cooling chamber 81 located inside a single rotor disk stacked between the front axle section 65A and the rear axle section 67.

[0073] Cooling fluid delivered to the annular space between adjacent rotor disks and below the corresponding sealed flow channel 68 purges the corresponding annular space and prevents process fluid from flowing through it. Therefore, the pressure of the cooling fluid must be sufficient to balance the pressure of the process fluid expanding along the expansion flow path formed by the stationary blades 53 and the rotor blades 55. The pressure of the process fluid decreases along the flow path from the first expander stage to the last expander stage. Therefore, the required pressure of the cooling fluid in the upstream expander stage is very high, and may, for example, be between 200 barA and 600 barA. The upstream rotor disk, integrally formed with the front shaft portion 65, and more specifically with its section 65B, provides sufficient mechanical strength to resist the high pressures that tend to separate the rotor disks from each other.

[0074] In the final stage of expander 3, such as in its last four stages, the pressure of the process fluid is lower, and therefore the pressure of the cooling fluid in the annular space between the rotor disks is also lower. The axial force that tends to separate the rotor disks from each other due to the pressure of the cooling fluid is small enough to allow the separate and stacked rotor disks to be assembled by tie rod 70. In order to provide cooling fluid at a gradually decreasing pressure in the annular space between the sequentially arranged rotor disks, the cooling fluid through the conduit through which it is delivered to the annular space may have a variable cross-section to provide an increasing head loss from the most upstream expander stage to the most downstream expander stage (i.e., in the forward-backward direction).

[0075] The first set of rotor disks (57.1, 57.2, 57.3 and 57.4) which are integrally formed with the front shaft section 65 (i.e., its section 65B) and the additional rotor disks (57.5, 57.6 and 57.7) stacked by means of tie rods 70 provide the required mechanical strength without the need to manufacture the entire rotor as a monolithic piece, for example, by forging.

[0076] Therefore, the combination of integral rotor disks and stacked rotor disks allows for the manufacture of large rotors to produce expanders with high power ratios. Obtaining the same rotor size is difficult, if not impossible, by forging the rotor into a single piece.

[0077] Although Figure 2 In this embodiment, the additional set of rotor disks integrated with the rear axle portion 67 includes a single rotor disk 57.8, but in other embodiments not shown, the additional set of rotor disks 57 may include a greater number of rotor disks, such as two, three or four rotor disks integrally formed with the rear axle portion 67 as a monolithic body.

[0078] exist Figure 3 A cross-sectional view shows another embodiment of the rotor that can be used in expander 3. The same reference numerals denote... Figure 2The same or equivalent parts shown and described above will not be described again.

[0079] Figure 3 Rotor 43 and Figure 2 The main difference in the rotor shown is that the rotor disks are divided into a first group of rotor disks 57.1, 57.2, 57.3, and 57.4, which are integrally formed as a single block with section 65B of the front shaft portion 65, and separate individual rotor disks 57.5, 57.6, 57.7, and 57.8, all of which are formed as separate components and arranged between and stacked with the front shaft portion 65 and the rear shaft portion 67. The front shaft portion 65 (and more specifically, its section 65B), rotor disks 57.5, 57.6, 57.7, and 57.8, and the rear shaft portion 67 are stacked on top of each other and interconnected by tie rods 70, as shown. Figure 3 As shown, or interconnected by different arrangements of tie rods (e.g., consisting of or including a central tie rod coaxial with the axis of rotation AA), as referenced above. Figure 2 As described above. In this embodiment, there is no additional rotor disk integrally formed with the rear axle portion 67. Figure 3 The implementation scheme has advantages over Figure 2 The advantage of this implementation scheme is that the rear axle portion is smaller and easier to manufacture using forging or other manufacturing techniques.

[0080] Exemplary embodiments have been disclosed above and illustrated in the accompanying drawings. Those skilled in the art will understand that various changes, omissions, and additions may be made to the specific disclosure herein without departing from the scope of the invention as defined in the following claims.

[0081] For example, while in the particularly advantageous embodiment disclosed above the burner is housed within the expander, in other embodiments the burner may be arranged outside the expander. Housed the burner within the outer casing 41 of the expander 3, resulting in a more compact arrangement.

[0082] In other embodiments, the expander can be used in a closed-loop thermodynamic cycle, such as a supercritical carbon dioxide cycle, in which heat is introduced into the thermodynamic cycle via a heat exchanger rather than a burner.

Claims

1. A rotor for a power generation turbine, the rotor comprising: Multiple rotor disks; wherein each rotor disk comprises a corresponding annular row of rotor blades in the expansion flow path of the power generation turbine; Front axle section; Rear axle section; as well as At least one cooling conduit, the at least one cooling conduit being adapted to supply cooling fluid to the rotor disk; in: The first set of rotor disks is integrally formed with the section of the front shaft portion; the first set of rotor disks and the section of the front shaft portion form an integral component; The front axle section and the rear axle section are connected to each other by a tie rod device.

2. The rotor according to claim 1, wherein the additional set of rotor discs is integrally formed with the rear shaft portion; and the rear shaft portion and the additional set of rotor discs form an integral component.

3. The rotor according to claim 1 or 2, wherein the rotor includes at least one additional rotor disk between the front shaft portion and the rear shaft portion; wherein the front shaft portion, the at least one additional rotor disk and the rear shaft portion are stacked on top of each other and connected to each other by the tie rod device.

4. The rotor according to claim 1, 2 or 3, wherein a plurality of additional rotor disks are positioned between the front shaft portion and the rear shaft portion; and wherein the front shaft portion, the plurality of rotor disks and the rear shaft portion are stacked on top of each other and connected to each other by the tie rod device.

5. The rotor according to one or more of claims 1 to 4, wherein the rotor further provides a cooling chamber therein, the cooling chamber being adapted to receive cooling fluid from the cooling conduit.

6. The rotor of claim 5, wherein the cooling chamber is disposed between the front shaft portion and the rear shaft portion.

7. The rotor according to claim 5 when dependent on claim 3, wherein the cooling chamber is formed between the front shaft portion, the at least one additional rotor disk, and the rear shaft portion.

8. The rotor according to one or more of the preceding claims, wherein the radial cooling conduits are fluidly connected to the annular space between the paired rotor disks arranged in sequence.

9. The rotor according to one or more of the preceding claims, wherein the tie rod device comprises: Multiple tie rods are arranged radially away from the axis of rotation of the rotor. A central tie rod, which is coaxial with the rotation axis of the rotor; or a combination of a central tie rod and a plurality of tie rods arranged around the rotation axis of the rotor.

10. The rotor according to one or more of the preceding claims, wherein the rotor further comprises a balancing drum.

11. The rotor according to claim 10, wherein the balance drum is formed on one of the front shaft portion and the rear shaft portion, preferably on the front shaft portion.

12. The rotor according to claim 10 or 11, wherein the balancing drum comprises a first balancing drum portion and a second balancing drum portion, the first balancing drum portion and the second balancing drum portion being connected to each other by at least one tie rod and preferably by a plurality of tie rods arranged radially around the axis of rotation of the rotor at a distance from the axis of rotation.

13. The rotor according to one or more of the preceding claims, wherein at least one of the rotor disks includes front teeth adapted to rotatably engage the rotor disk with at least one of: an adjacent rotor disk, the front shaft portion, and the rear shaft portion.

14. The rotor according to one or more of the preceding claims, wherein at least one cooling conduit extends in the front shaft portion and is fluidly connected to an annular space between the rotor disk integrally formed with the front shaft portion.

15. The rotor according to any one of the preceding claims, wherein the rotor comprises at least four, preferably at least six, more preferably at least eight expansion stages.

16. A power generation turbine, the power generation turbine comprising: External casing; as well as The rotor according to any one of the preceding claims is housed in the housing for rotation.

17. The turbine of claim 16, wherein the turbine is an expander.

18. The turbine according to claims 16 and 17, wherein the outer casing comprises a high-pressure casing and a low-pressure exhaust casing; wherein the high-pressure casing and the low-pressure exhaust casing are connected along a plane orthogonal to the axis of rotation.

19. The turbine of claim 18, wherein the high-pressure housing comprises an integral barrel.

20. The turbine of claim 18 or 19, wherein the low-pressure exhaust casing is constructed as an integral body.

21. The turbine according to any one of claims 16 to 20, the turbine further comprising at least one burner housed in the outer casing.

22. The turbine according to claim 18, 19 or 20, the turbine further comprising at least one burner housed in a support formed in the high-pressure housing.

23. The turbine according to claim 21 or 22, wherein the low-pressure exhaust casing is disposed on the low-pressure side of the expander opposite to the combustor; and wherein the low-pressure exhaust casing forms an exhaust volute.

24. The turbine according to any one of claims 16 to 23, the turbine further comprising at least one inner housing, and preferably comprising a plurality of inner housings, the at least one inner housing being fixedly housed in the outer housing and surrounding the rotor; wherein each inner housing is separated into a first housing portion and a second housing portion along a plane parallel to the axis of rotation of the rotor; and wherein the inner housing comprises an annular row of fixed blades.

25. The turbine according to any one of claims 16 to 24, wherein the rotor is adapted to receive process gas with a temperature T between 800°C and 1500°C.

26. The turbine according to any one of claims 16 to 25, wherein the rotor is adapted to receive process gas with a pressure higher than 50 barA, preferably equal to or higher than 100 barA, more preferably equal to or higher than 200 barA, and preferably lower than 800 barA, more preferably lower than 650 barA.

27. The turbine according to any one of claims 16 to 26, wherein the turbine is adapted to generate power of more than 50 MW, preferably equal to or greater than 100 MW, preferably less than 2000 MW, and more preferably less than 1500 MW.

28. A supercritical carbon dioxide thermodynamic circuit, the supercritical carbon dioxide thermodynamic circuit comprising: Oxidizing agent source; An expander having an inlet side and an outlet side, wherein the inlet side is fluidly connected to the oxidant source; A flue gas recirculation line, the flue gas recirculation line being adapted to recirculate flue gas from the exhaust side of the expander to the burner of the expander; A cooler, located in the flue gas recirculation line, is adapted to cool the flue gas from the exhaust side of the expander and condense water contained in the flue gas. A regenerative heat exchanger in which flue gas from the expander exchanges heat with quenched flue gas from the cooler; The expander thereon is an expander according to any one of claims 16 to 27.

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