gas turbine

Abstract

To provide a gas turbine capable of more effectively suppressing combustion vibration.SOLUTION: A gas turbine includes: a rotor rotatable about the axial line; a cabin casing covering the rotor in the circumferential direction and having an annular space therein; a compressor generating high-pressure compressed air by compressing outside air and sending out the compressed air into the cabin casing; a plurality of combustors disposed at even intervals in the circumferential direction of the rotor in the cabin casing and burning the compressed air taken in from the cabin casing and fuel to generate combustion gas; a turbine driven by the combustion gas; and air introduction passages that are defined by partition plates dividing the space in the cabin casing in the circumferential direction of the rotor and an inner peripheral surface of the cabin casing and introduce the compressed air in the cabin casing to the combustors.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to gas turbines. [Background technology]

[0002] A gas turbine has as its main components a compressor that compresses air, a combustor that burns fuel with the air compressed by the compressor to generate combustion gas, and a turbine that is driven by the combustion gas from the combustor.

[0003] The combustor has an outer cylinder and an inner cylinder provided inside the outer cylinder, and an air flow path through which compressed air compressed by a compressor flows is formed between the inner peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder. Inside the inner cylinder, there are provided a plurality of main burners arranged at equal intervals around the central axis of the combustor and which inject fuel for premixed combustion, and a pilot burner arranged at the central axis position of the combustor.

[0004] Combustors that perform premixed combustion may experience combustion oscillation. Patent Document 1, for example, describes a combustion oscillation reduction device as a technique for reducing combustion oscillation. The combustion oscillation reduction device includes a hole provided in at least one of the combustor, a duct connected to the combustor, and a casing; a filler member with low acoustic impedance and high fluid impedance that is arranged to block the hole; and a valve that controls the opening degree of the hole. Changing the opening degree of the hole changes the acoustic characteristics (particularly frequency) of the combustor. Generally, opening a hole increases the frequency. The combustion oscillation reduction device described in Patent Document 1 reduces combustion oscillation by adjusting the frequency, mode, and damping by controlling the opening degree of the hole by adjusting the valve.

[0005] Furthermore, Patent Document 2 describes a combustion oscillation reduction device (acoustic damper) that includes an annular pipe disposed outside the rear end of a combustor (outside the casing in which the combustor is installed), a throat that connects the annular pipe to the combustor, and a resistor with numerous through holes that is provided at the end of the throat on the combustor side. In the combustion oscillation reduction device described in Patent Document 2, fluid particles, which are the vibrating elements of combustion oscillations generated in the combustion region inside the combustor, resonate with the air inside the tubular pipe connected by the throat and vibrate near the resistor. This vibration damps the vibration of the fluid particles in the combustor, reducing combustion oscillations. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 3233798 [Patent Document 2] Patent No. 3999645 Summary of the Invention [Problem to be solved by the invention]

[0007] The oscillation conditions for combustion oscillation and pressure fluctuations in a combustor can be expressed by the following equation (1) for the Rayleigh index R, where T is the period of the fluctuations, where Δp is the pressure fluctuation and Δq is the heat generation fluctuation.

[0008]

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[0009] The magnitude of the left-hand side of equation (1) depends on the pressure mode, the position of the heat source, and the time delay (the natural frequency of the acoustic system and the time delays of the supply system and combustion system). By adjusting the size of the mounting hole, the mounting location, volume, etc., the combustion vibration reduction device can adjust the pressure mode and the natural frequency of the acoustic system, reducing the value of the left-hand side and suppressing the occurrence of vibration. In addition, drilling holes increases the field damping on the right-hand side, which can help suppress combustion vibration.

[0010] From equation (1), it is clear that the Rayleigh index R is the covariance of pressure and heat generation, and is therefore expressed as equation (2).

[0011]

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[0012] To be stable, Δq when Δp is the prior information, that is, Δq|Δp in equation (3) must have the opposite sign to Δp.

[0013]

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[0014] That is, when the pressure dependence of heat generation q is expressed by equation (4), kq<0 is the condition for stability according to the Rayleigh index R.

[0015]

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[0016] However, the Rayleigh index R does not include a term for the air (compressed air) flow and only considers the heat generation q. For this reason, there was a need for technology that could more effectively suppress combustion oscillation by taking into account fluctuations in the air flow.

[0017] The present disclosure has been made in consideration of such problems, and provides a gas turbine that can more effectively suppress combustion oscillation. [Means for solving the problem]

[0018] According to one aspect of the present disclosure, a gas turbine includes a rotor rotatable about an axis, a casing that circumferentially covers the rotor and has an annular space inside, a compressor that compresses external air to generate high-pressure compressed air and sends it into the casing, a plurality of combustors that are arranged at equal intervals circumferentially around the rotor inside the casing and that combust the compressed air taken in from the casing with fuel to generate combustion gas, a turbine that is driven by the combustion gas, and an air introduction passage that is defined by a partition plate that divides the space inside the casing circumferentially around the rotor and an inner surface of the casing and that introduces the compressed air inside the casing into the combustors.

[0019] According to one aspect of the present disclosure, a gas turbine includes a rotor rotatable about an axis, a casing that circumferentially covers the rotor and has an annular space inside, a compressor that compresses external air to generate high-pressure compressed air and sends it into the casing, a plurality of combustors that are arranged at equal intervals around the rotor inside the casing and that combust the compressed air taken in from the casing with fuel to generate combustion gas, a turbine that is driven by the combustion gas, and an annular air inlet passage that is defined by a first cylindrical portion that surrounds the combustor and a second cylindrical portion that surrounds the first cylindrical portion and that introduces the compressed air in the casing into the combustor.

[0020] According to one aspect of the present disclosure, a gas turbine includes a rotor rotatable about an axis, a casing that circumferentially covers the rotor and has an annular space inside, a compressor that compresses external air to generate high-pressure compressed air and sends it into the casing, a plurality of combustors that are arranged at equal intervals around the rotor inside the casing and that combust the compressed air taken in from the casing with fuel to generate combustion gas, a turbine that is driven by the combustion gas, and an air inlet passage that introduces the compressed air inside the casing into the combustors. The air introduction passage is defined by a first wall portion having an L-shaped cross section, the first wall portion including a first plate portion extending from an outer peripheral surface of the combustor and a second plate portion extending from the first plate portion downstream in the axial direction of the rotor, and a second wall portion having a U-shaped cross section, the second wall portion including a third plate portion extending from an inner peripheral surface of the casing to the downstream in the axial direction of the rotor, a fourth plate portion extending from the third plate portion toward the outer peripheral surface of the combustor, and a fifth plate portion extending from the fourth plate portion upstream in the axial direction of the rotor. The second plate portion of the first wall portion is disposed between the third plate portion and the fifth plate portion of the second wall portion.

[0021] According to one aspect of the present disclosure, a gas turbine includes a rotor rotatable about an axis, a casing that circumferentially covers the rotor and has an annular space inside, a compressor that compresses external air to generate high-pressure compressed air and sends it into the casing, a plurality of combustors that are arranged at equal intervals around the rotor inside the casing and that combust the compressed air taken in from the casing with fuel to generate combustion gas, a turbine that is driven by the combustion gas, and an air introduction passage defined by a plurality of guide pipes that have a first opening connected to an inlet of the combustor and a second opening that opens axially downstream of the rotor in the space inside the casing. [Effects of the Invention]

[0022] According to the gas turbine according to the present disclosure, combustion oscillation can be more effectively suppressed. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a schematic diagram illustrating a configuration of a gas turbine according to a first embodiment of the present disclosure. [Figure 2] 1 is a cross-sectional view taken along a rotor axis, illustrating a schematic configuration of a combustor and its surroundings of a gas turbine according to a first embodiment of the present disclosure. [Figure 3] FIG. 2 is a diagram illustrating a model of a combustor according to the first embodiment of the present disclosure. [Figure 4] FIG. 3 is a diagram illustrating an example of a stable condition of the combustor according to the first embodiment of the present disclosure. [Figure 5] 1 is a cross-sectional view seen from the rotor axial direction, showing a schematic configuration of a combustor and its surroundings of a gas turbine according to a first embodiment of the present disclosure. [Figure 6] 1 is a schematic diagram of a combustor and its surroundings of a gas turbine according to a first embodiment of the present disclosure. [Figure 7] FIG. 2 is a schematic diagram of a combustor and its surroundings of a gas turbine according to a first modified example of the first embodiment of the present disclosure. [Figure 8] FIG. 10 is a schematic diagram of a combustor and its surroundings of a gas turbine according to a second modification of the first embodiment of the present disclosure. [Figure 9] FIG. 11 is a cross-sectional view showing a schematic configuration of a combustor and its surroundings of a gas turbine according to a third modification of the first embodiment of the present disclosure, as viewed from the rotor axial direction. [Figure 10] FIG. 10 is a schematic diagram of a combustor and its surroundings of a gas turbine according to a third modification of the first embodiment of the present disclosure. [Figure 11] FIG. 10 is a schematic diagram of a combustor and its surroundings of a gas turbine according to a fourth modification of the first embodiment of the present disclosure. [Figure 12] FIG. 4 is a cross-sectional view taken along a rotor axis, illustrating a schematic configuration of a combustor and its surroundings in a gas turbine according to a second embodiment of the present disclosure. [Figure 13] FIG. 10 is a cross-sectional view taken along a rotor axis, illustrating a schematic configuration of a combustor and its surroundings of a gas turbine according to a third embodiment of the present disclosure. [Figure 14] FIG. 10 is a cross-sectional view taken along the rotor axis, illustrating a schematic configuration of a combustor and its surroundings in a gas turbine according to a fourth embodiment of the present disclosure. [Figure 15] FIG. 10 is a cross-sectional view taken along a combustor axis, illustrating a schematic configuration of a combustor according to a fifth embodiment of the present disclosure. [Figure 16] FIG. 10 is a cross-sectional view illustrating a schematic configuration of a combustor according to a fifth embodiment of the present disclosure, as viewed in the axial direction of the combustor. [Figure 17] FIG. 13 is a cross-sectional view taken along a combustor axis, illustrating a schematic configuration of a combustor according to a modified example of the fifth embodiment of the present disclosure. [Figure 18] FIG. 10 is a cross-sectional view taken along a combustor axis, illustrating a schematic configuration of a combustor according to a sixth embodiment of the present disclosure. [Figure 19] FIG. 10 is a cross-sectional view taken along a combustor axis, illustrating a schematic configuration of a combustor according to a seventh embodiment of the present disclosure. [Figure 20] FIG. 12 is a cross-sectional view illustrating a schematic configuration of a combustor according to a seventh embodiment of the present disclosure, as viewed in the axial direction of the combustor. DETAILED DESCRIPTION OF THE INVENTION

[0024] First Embodiment A gas turbine according to a first embodiment of the present disclosure will be described below with reference to the drawings.

[0025] (Overall composition) FIG. 1 is a schematic diagram showing the configuration of a gas turbine according to a first embodiment of the present disclosure. As shown in FIG. 1, the gas turbine 1 according to this embodiment includes a rotor 4, a casing 5, a compressor 2, a plurality of combustors 10, and a turbine 3.

[0026] The rotor 4 rotates about the rotor axis Ar and connects the compressor 2 and the turbine 3. Here, the direction in which the rotor axis Ar extends is referred to as the rotor axial direction Da, with one of the two ends of the rotor axial direction Da being the axial upstream side Dau and the other being the axial downstream side Dad. The circumferential direction relative to the rotor axis Ar is referred to as the rotor circumferential direction Dcr. The direction perpendicular to the rotor axis Ar is referred to as the rotor radial direction Drr. The side closer to the rotor axis Ar is referred to as the rotor radial inner side Drri, and the side away from the rotor axis Ar is referred to as the rotor radial direction Drro.

[0027] The casing 5 covers the rotor 4 in the circumferential direction Dcr and has an annular space therein.

[0028] The compressor 2 takes in external air as a working fluid, generates compressed air (air) A, and sends it into the casing 5.

[0029] 1, the plurality of combustors 10 are arranged at equal intervals in the circumferential direction of the rotor 4 inside the casing 5. Each combustor 10 is connected to the outlet of the compressor 2, and mixes fuel with compressed air A supplied from the compressor 2 and combusts the mixture to generate high-temperature and high-pressure combustion gas G.

[0030] The turbine 3 converts the thermal energy of the combustion gas G sent out from the combustor 10 into rotational energy of the rotor 4. Then, this rotational energy is transmitted to a generator (not shown) connected to the rotor 4.

[0031] The combustors 10 are radially disposed with their respective combustor axes Ac inclined relative to the rotational axis Ar of the rotor 4 of the gas turbine 1 such that the inlet side of the combustor 10 is radially away from the outlet side.

[0032] FIG. 2 is a cross-sectional view taken along the rotor axis, showing a schematic configuration of the vicinity of a combustor of a gas turbine according to a first embodiment of the present disclosure. As shown in FIG. 2, each combustor 10 includes an outer casing 11, an inner casing 12, a plurality of burners 13, and a transition piece 15.

[0033] The outer cylinder 11, the inner cylinder 12, and the transition piece 15 are disposed in a space within the casing 5, which is a double annular closed space concentric with the rotor 4. The outer cylinder 11, the inner cylinder 12, and the transition piece 15 are all cylindrically shaped around the combustor axis Ac.

[0034] Here, the direction in which the combustor axis Ac extends is referred to as the axial direction Dc, and one of the two ends of the axial direction Dc is referred to as the tip side Dct, and the other is referred to as the base side Dcb. As shown in FIGS. 1 and 2 , the tip side Dct corresponds to the axial downstream side Dad in the rotor axial direction Da, and the base side Dcb corresponds to the axial upstream side Dau in the rotor axial direction Da. The combustor axis Ac is inclined with respect to the rotor axis Ar so as to approach the rotor axis Ar toward the tip side Dct. The circumferential direction with respect to the combustor axis Ac is referred to as the circumferential direction Dcc. The direction perpendicular to the combustor axis Ac is referred to as the radial direction Drc. The side closer to the combustor axis Ac is referred to as the inner circumferential side or radially inner side Drci, and the side away from the combustor axis Ac is referred to as the outer circumferential side or radially outer side Drco.

[0035] The outer casing 11 has a flange 11f that extends radially outward from the combustor axis Ac to the casing 5. The flange 11f is attached to the casing 5 with bolts so as to close a combustor mounting hole provided in the casing 5.

[0036] The inner cylinder 12 is attached to the inner periphery of the outer cylinder 11 with a gap between it and the flange 11f. A plurality of burners 13 are arranged on the inner periphery of the inner cylinder 12. A transition piece 15 is connected to the tip side Dct of the inner cylinder 12.

[0037] Each of the multiple burners 13 (13a, 13b) extends in the axial direction Dc and has holes formed therein for injecting fuel. All of the multiple burners 13 are fixed to the outer casing 11. The multiple burners 13 consist of a pilot burner 13a and main burners 13b. The pilot burner 13a is disposed on the combustor axis Ac. The multiple main burners 13b are arranged around the pilot burner 13a at equal intervals in the circumferential direction Dcc.

[0038] (About combustion vibration) FIG. 3 is a diagram illustrating a model of a combustor according to the first embodiment of the present disclosure. The model shown in Figure 3 is a combustor 10 in which the flow of air (compressed air A) is made positive and concentrated. In Figure 3, point A is the inlet-side boundary point of the combustor 10 (the boundary point on the compressor 2 side), point B is a single point representing the spatial extent of the combustor 10, and point C is the outlet-side boundary point of the combustor 10 (the boundary point on the turbine 3 side). Point B represents the air g flowing in from the inlet-side boundary point A. A (kg / s) and the air g flowing out to the outlet boundary point B B (kg / s). The specific enthalpy of the inflow and outflow air is h A (J / kg) and h B (J / kg). The volume of the combustor 10 is V (m 3 ), the mass of air in the combustor 10 is m B (kg).

[0039] The mass balance of the combustor 10 is expressed by the following equation (5). The symbol · above the symbol represents time differentiation. For example, m B ^· is the mass m B is the rate of change of mass (kg) over time (kg / s).

[0040]

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[0041] The energy balance of the combustor is expressed by the following equation (6): For simplicity, only the heat generation q of the fuel is considered, and the mass of the fuel is not taken into account.

[0042]

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[0043] The specific volume of air in the combustor is v B (p B ,h B ) the relationship between pressure and specific enthalpy is expressed by the following equation (7).

[0044]

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[0045] Since the volume V does not change with time, the time derivative of V is zero. Therefore, the following equation (8) is obtained for the pressure in the combustor.

[0046]

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[0047] Here, the settling state of the combustor is expressed as the flow rate of the inflow air g A,e , specific enthalpy h A,e , and heat generation qe, and the fluctuation in the state of the combustor 10 is expressed as the pressure fluctuation Δp B It is expressed as:

[0048]

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[0049] Substituting this into the pressure equation, we obtain a linear approximation model for the dynamic characteristics of pressure, as shown in the following equation (10).

[0050]

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[0051] When the solution of this linear approximation model is expressed as equation (11) and substituted into equation (10) above, the characteristic equation expressed as equation (12) is obtained.

[0052]

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[0053]

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[0054] The characteristic root λ is expressed as equation (13).

[0055]

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[0056] If the characteristic root is positive, the dynamic characteristics of pressure are unstable, and if it is negative, it is stable. We will explain the positive and negative cases of the characteristic root separately.

[0057] Case 1 is a case where the air flow rate is assumed to be constant. If the flow rate is constant, then k in equation (13) above is gA and k gB is zero. In that case, the characteristic root is given by the following equation (14).

[0058]

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[0059] When the pressure is increased, the gas contracts, so (dv / dp) h is negative, and gas expands when heated, so (dv / dh) p is positive. However, the denominator, which is the weighted sum of the two, is (dv / dp) h Since the term is dominant, the sign of the denominator is ultimately positive. Therefore, the condition for the characteristic root to be negative, i.e., the stability condition, is expressed by equation (15), which is the same result as the Rayleigh index mentioned earlier.

[0060]

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[0061] From Case 1, it can be inferred that the Rayleigh index represents the stable condition when the air flow rate does not change and only the heat generation changes.

[0062] Case 2 is a more realistic case in which the air flow rate varies depending on the pressure of the combustor 10. In this embodiment, attention is focused on Case 2. In Case 2, the numerator of the characteristic root equation (16) (i.e., k gA and k gB and k q The condition for stability is that the weighted sum of

[0063]

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[0064] k gB The weighting factor of (-v B,e ) and this value is negative, so k gB The larger k is, the more effective it is in preventing combustion oscillation. In other words, it is better for air to flow easily toward the outlet. gA The weighting factor of (v B,e -(dv / dh) p q e / g A,e ) In recent gas turbines, the combustor outlet temperature has increased to improve efficiency, and the absolute temperature at the combustor inlet and outlet is nearly three times higher. gA The load factor is (1 / 3) × v B,e That is, the absolute temperature T B is the absolute temperature at the inlet, T A In modern gas turbines, which are about three times larger than the conventional turbines, the characteristic equation is expressed as in equation (17). The sign of the characteristic root is related to the air flow rate k gA and k gB It is also important to note that this depends on

[0065]

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[0066] As initially predicted, realistic modeling revealed that the air flow rate also affects combustion oscillation. Based on this result, we will consider ways to avoid combustion oscillation.

[0067] Inflow air g Aand outflow air g B The conservation of momentum is expressed by the following equation (18). For simplicity, air friction is ignored.

[0068]

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[0069] For the sake of simplicity, the motion of a mass system can be divided into the motion of the center of gravity and the relative motion. A and g B The baseline flow rate is divided into two parts: the baseline where both increase and decrease simultaneously, and the relative flow rate where both increase and decrease alternately like a seesaw. A,e , the relative flow rate is ξ A ,ξ B As g A and g B is expressed as the following equation (19).

[0070]

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[0071] The total momentum for the baseline flow rate is g A and g B In the momentum equation of g A,e By substituting and adding up, the baseline flow rate is expressed as the following equation (20). B Since the baseline flow rate is independent of combustion oscillations, the integral calculation part of the following equation (20) represents the equivalent length of the flow path with respect to inertia.

[0072]

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[0073] On the other hand, the g caused by combustion oscillation A and g B Since the relative motion of each of them moves in the opposite direction, the total momentum of the relative motion of each of them is expressed as ξ as shown in the following equation (21). A and ξ BThe flow rate due to the relative motion reflects the compression and expansion of the gas in the combustor, and this represents combustion oscillation.

[0074]

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[0075] In combustion oscillation, momentum is only exchanged locally between the inlet and outlet flow paths of the combustor, so the sum of the momentum of both is zero, as expressed by equation (22).

[0076]

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[0077] For the sake of simplicity, the ratio of the equivalent lengths of the inflow and outflow channels is defined as R as in equation (23). AB It is written as follows.

[0078]

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[0079] Since the sum of the momentum of both the inflow and outflow is zero, the flow rate due to relative motion is expressed by the following equation (24).

[0080]

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[0081] ξ A and ξ B The ratio of k gB and k gA Since this is equal to the ratio of

[0082]

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[0083] Substituting this into equation (17), the characteristic root is expressed by equation (26).

[0084]

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[0085] Since the value of the denominator in equation (26) is positive, the stability condition is expressed by the following equation (27).

[0086]

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[0087] If the fluid in the combustor is approximated as an ideal gas, the above equation (27) can be expressed as the following equation (28).

[0088]

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[0089] From equation (28), stability is determined by the ratio of the equivalent lengths of the inflow and outflow channels, R AB It turns out that it depends on.

[0090] FIG. 4 is a diagram illustrating an example of a stable condition for the combustor according to the first embodiment of the present disclosure. Inflow flow coefficient k gA Since the value of is negative, k gA For the region where R < 0, the stability condition is obtained as shown in Figure 4. The dashed line L1 in Figure 4 indicates the AB The solid line L2 indicates the stable region when R AB The stable region is shown when R = 1. The ratio of the equivalent lengths of the inflow and outflow channels is R AB It can be seen that the stable range expands as the ratio of the equivalent lengths of the flow channels R increases. AB A gas turbine 1 having a configuration for avoiding combustion oscillation from this viewpoint will be described.

[0091] (Regarding compressed air flow) FIG. 2 shows compressed air A in the space within the casing 5 flowing along a meridian plane including the rotor axis Ar and the combustor axis Ac. A compressor outlet passage F1 is connected to the casing 5 at the radially inner side Drri of the rotor 4. Compressed air A compressed by the compressor 2 flows into the casing 5 from the compressor outlet passage F1. The flowing compressed air A reverses its flow direction in the rotor axis direction Da and heads toward the inlet (base end side Dcb) of the combustor 10. The annular space between the inner circumferential surface 11a of the external cylinder 11 and the outer circumferential surface 12a of the internal cylinder 12 forms a part of an air introduction passage F2 that introduces the compressed air A in the casing 5 into the internal cylinder 12. The internal cylinder 12 is disposed with a gap between it and a flange 11f of the external cylinder 11. The compressed air A in the air introduction passage F2 flows into the internal cylinder 12 through the gap between the internal cylinder 12 and the flange 11f. The compressed air A that has flowed into the inner cylinder 12 flows out into the transition piece 15. Fuel is injected into the transition piece 15 from the burner 13. This fuel is mixed with the compressed air A and combusted in the transition piece 15 to generate combustion gas G. The combustion gas G is led from the transition piece 15 into the turbine 3.

[0092] In conventional gas turbines, the space within the casing is common to multiple combustors and has no internal partitions, allowing compressed air to flow freely within the casing in the circumferential direction of the rotor, i.e., in the direction perpendicular to the meridian plane.

[0093] When there are multiple combustors, differences in the pressure in the combustion chambers of each combustor are unavoidable. When compressed air is distributed to each combustor from a space inside the casing (hereinafter also referred to as the "air introduction passage") that is common to multiple combustors, if the internal pressure of one combustor rises, the supply of compressed air to that combustor will decrease, and the decrease will be diverted to the other combustors to balance it out.

[0094] As explained in equation (26) above, when the combustor pressure increases, the greater the reduction in the intake air flow rate, the more likely combustion oscillation occurs. Considering this, when the internal pressure of one combustor increases, it is not desirable from the perspective of combustion oscillation if the compressed air that had been supplied to that combustor is diverted to other combustors.

[0095] (Configuration for suppressing combustion vibration) In conventional technology, an acoustic damper is attached to the combustor body to suppress combustion oscillation. In contrast, in this embodiment, based on the above-mentioned findings, attention is focused on the air introduction passage to the combustor 10. The focus is on the result of the study of Case 2 based on the Rayleigh index, which states that combustion oscillation becomes more likely as the intake air flow rate decreases when the combustor pressure increases. In other words, the gas turbine 1 according to this embodiment suppresses a decrease in the intake air flow rate of one of the multiple combustors 10 even when the pressure in that combustor increases. Alternatively, it suppresses an increase in the intake air flow rate of that combustor 10 when the pressure in that combustor decreases. For this reason, in this embodiment, the equivalent length of the air introduction passage to the combustor 10 in terms of inertia is lengthened. Note that, in addition to lengthening the equivalent length in terms of inertia, the differential pressure in the air introduction passage may be increased; however, increasing the differential pressure may reduce the efficiency of the heat engine.

[0096] FIG. 5 is a cross-sectional view showing a schematic configuration of the vicinity of a combustor of a gas turbine according to a first embodiment of the present disclosure, as viewed from the rotor axis direction. FIG. 6 is a schematic diagram of the vicinity of a combustor of a gas turbine according to the first embodiment of the present disclosure. As shown in Figures 5 and 6, the gas turbine 1 according to this embodiment further includes an air introduction passage F2 that is defined by a partition plate 20 that divides the space inside the casing 5 in the circumferential direction Dcr of the rotor 4 and inner circumferential surfaces 5a, 5b of the casing 5 and that introduces compressed air A inside the casing 5 into the combustor 10.

[0097] The partition plate 20 extends in the rotor radial direction Drr from the inner circumferential surface 5a of the rotor radially outer side Drro of the casing 5 to the inner circumferential surface 5b of the rotor radially inner side Drri. In addition, the partition plate 20 extends in the rotor axial direction Da from the inlet (base end side Dcb) of the inner cylinder 12 to the outlet (tip end side Dct) of the transition piece.

[0098] The air introduction passage F2 allows the compressed air A that has flowed in from the compressor outlet passage F1 to flow to the base end side Dcb of the combustor 10, and introduces it into the combustor 10 (inner cylinder 12).

[0099] In this embodiment, the partition plate 20 is provided between each of the plurality of combustors 10, thereby dividing the space inside the casing 5 into independent air introduction paths F2 for each combustor 10. By providing an independent air introduction path F2 for each combustor 10 in this way, when the internal pressure of a certain combustor 10 rises, it is possible to prevent the compressed air A from bypassing that combustor 10 and flowing into the other combustors 10. This makes it possible to suppress combustion oscillation.

[0100] Furthermore, in the conventional technology, when the internal pressure of a combustor increases and the supply flow rate of compressed air to the combustor decreases, abnormal combustion called flashback, in which a flame swims back, may occur in the compressed air. However, the gas turbine 1 according to this embodiment reduces the bypassing of the compressed air A and suppresses a decrease in the supply flow rate to the combustor 10, even when the internal pressure of the combustor 10 increases. As a result, the gas turbine 1 according to this embodiment can suppress the occurrence of flashback in the combustor 10.

[0101] 5 and 6 show an example in which the partition plate 20 is disposed so as not to interfere with the combustor 10, but the present invention is not limited to this. In other embodiments, the partition plate 20 may be disposed so as to be inclined with respect to the meridian plane and to cross the combustor 10.

[0102] 5 and 6 show an example in which a partition plate 20 is provided between adjacent combustors 10 to form an independent air introduction passage F2 for each combustor 10, but the present invention is not limited to this. In other embodiments, the partition plates 20 may be thinned out. For example, two adjacent combustors 10 may be grouped together, and a partition plate 20 may be provided between each group to form an independent air introduction passage F2 for each group. This allows the air introduction passage F2 to be formed with a simpler configuration.

[0103] (Action and effect) As described above, the gas turbine 1 according to this embodiment includes the rotor 4 rotatable about the axis Ar, the casing 5 that covers the rotor 4 in the circumferential direction Dcr and has an annular space therein, the compressor 2 that compresses external air to generate high-pressure compressed air A and sends it into the casing 5, a plurality of combustors 10 that are arranged at equal intervals in the circumferential direction Dcr of the rotor 4 inside the casing 5 and combust fuel with the compressed air A taken in from the casing 5 to generate combustion gas G, the turbine 3 that is driven by the combustion gas G, the partition plate 20 that divides the space inside the casing 5 in the circumferential direction Dcr of the rotor 4, and the air introduction passage F2 that is defined by the inner peripheral surface 5a of the casing 5 and introduces the compressed air A inside the casing 5 into the combustor 10.

[0104] With this configuration, the gas turbine 1 can suppress the compressed air A in the casing 5 from diverting from one combustor 10 to the other combustors 10 when the internal pressure of that combustor 10 rises. This suppresses an increase or decrease in the supply flow rate of the compressed air A to each combustor 10 due to fluctuations in the combustor pressure. Furthermore, since it is possible to suppress a decrease in the compressed air A supplied to the combustor 10 whose internal pressure has risen, it becomes possible to suppress combustion oscillation and flashback in that combustor 10.

[0105] Furthermore, the partition plates 20 are provided in the middle of each of the plurality of combustors.

[0106] As a result, the gas turbine 1 can have an independent air introduction passage F2 for each combustor 10, and therefore, even if the internal pressures of the combustors 10 are different, it is possible to suppress differences in the flow rates of the compressed air A supplied to the combustors 10. This makes it possible to more reliably suppress combustion oscillation.

[0107] <Modification 1 of the First Embodiment> Next, a gas turbine 1 according to a first modification of the first embodiment will be described. Components common to the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0108] FIG. 7 is a schematic diagram of the vicinity of a combustor of a gas turbine according to a first modification of the first embodiment of the present disclosure. As shown in FIG. 7, in the gas turbine 1 according to this embodiment, a baffle plate 21 for diverting the compressed air A is provided inside the air introduction passage F2.

[0109] At least one baffle plate 21 is provided in the air introduction passage F2. The number of baffles 21 may be increased or decreased as desired. In the example of Fig. 7, three baffles 21a, 21b, and 21c are provided in this order from the upstream side of the air introduction passage F2 (i.e., the axial downstream side Dad).

[0110] The baffle plates 21a and 21c extend from the inner circumferential surface 5b of the rotor radially inner side Drri of the casing 5 toward the rotor radially outer side Drro, and have a gap between them and the inner circumferential surface 5a of the rotor radially outer side Drro of the casing 5.

[0111] The baffle plate 21b extends from the inner circumferential surface 5a of the casing 5 on the rotor radially outer side Drro toward the rotor radially inner side Drri, and has a gap with the inner circumferential surface 5b of the casing 5 on the rotor radially inner side Drri.

[0112] The inner cylinder 12 and the transition piece 15 of the combustor 10 are disposed to pass through the baffle plates 21a to 21c.

[0113] Compressed air A flowing into the casing 5 from the compressor outlet flow path F1 collides with the baffle 21a and then flows along the baffle 21a toward the rotor radially outer side Drro. Compressed air A passing through the gap between the baffle 21a and the inner circumferential surface 5a collides with the baffle 21b and then flows along the baffle 21b toward the rotor radially inner side Drri. Compressed air A passing through the gap between the baffle 21b and the inner circumferential surface 5b collides with the baffle 21c and then flows along the baffle 21c toward the rotor radially outer side Drro. Compressed air A passing through the gap between the baffle 21c and the inner circumferential surface 5a flows into the combustor 10 (inner cylinder 12) through the gap between the inner circumferential surface 11a of the outer cylinder 11 and the outer circumferential surface 12a of the inner cylinder 12. In this way, the compressed air A flowing through the air introduction path F2 is introduced into the combustor 10 while being changed in direction by the baffle 21. That is, the baffle plate 21 extends the flow path length of the air introduction path F2.

[0114] In this way, by providing the baffle plate 21 inside the air introduction path F2 to divert the compressed air A, it is possible to increase the flow path length of the air introduction path F2 (increase the equivalent length with respect to inertia). This makes it possible to suppress a decrease in the supply flow rate of the compressed air A due to an increase in the internal pressure of the combustor 10, and to suppress combustion oscillation.

[0115] <Modification 2 of the First Embodiment> Next, a gas turbine 1 according to a second modification of the first embodiment of the present disclosure will be described. Components common to the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0116] FIG. 8 is a schematic diagram of the vicinity of a combustor of a gas turbine according to a second modification of the first embodiment of the present disclosure. 8, in the gas turbine 1 according to this embodiment, the partition plate 20 is provided with communication holes 22 that communicate with the air introduction passages F2 adjacent to each other in the rotor circumferential direction Dcr. The communication holes 22 are formed by attaching a material that provides flow resistance, such as a punched metal, to the partition plate 20.

[0117] In this way, by providing the communication holes 22 in the partition plate 20, when the pressure in one combustor 10 becomes higher than that in the other combustors 10, a flow occurs in the communication holes 22 due to the bypass of the compressed air A.

[0118] In the conventional technology, since there is no flow resistance inside the casing, no damping effect can be obtained even if the compressed air is bypassed to the adjacent combustor. In contrast, in the gas turbine 1 according to this modification, by providing flow resistance to the communication holes 22, the bypassed flow of the compressed air A acts as a damping force, thereby suppressing pressure fluctuations.

[0119] <Modification 3 of the First Embodiment> Next, a gas turbine 1 according to a third modification of the first embodiment will be described. Components common to the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0120] FIG. 9 is a cross-sectional view showing a schematic configuration of a combustor and its surroundings of a gas turbine according to a third modification of the first embodiment of the present disclosure, as viewed from the rotor axis direction. FIG. 10 is a schematic diagram of the vicinity of a combustor of a gas turbine according to a third modification of the first embodiment of the present disclosure. As shown in Figures 9 and 10, in the gas turbine 1 according to this modified example, the partition plate 20 extends to the compressor outlet flow path F1 in the rotor radial direction Drr and divides the compressor outlet flow path F1 into multiple sections in the rotor circumferential direction Dcr.

[0121] In this way, by dividing the compressor outlet flow path F1 into independent flow paths for each combustor 10 using the partition plate 20, the length of the air introduction path F2 of each combustor 10 can be extended by the length of the compressor outlet flow path F1. This makes it possible to suppress a decrease in the supply flow rate of the compressed air A due to an increase in the internal pressure of the combustor 10, and further enhances the effect of suppressing combustion oscillation.

[0122] <Fourth Modification of the First Embodiment> Next, a gas turbine 1 according to a fourth modification of the first embodiment of the present disclosure will be described. Components common to the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0123] In the above-described embodiment and modified examples, a combustor type called an annular type in which a plurality of cylindrical combustors 10 are arranged in parallel in the rotor circumferential direction Dcr in the space inside the casing 5 has been described as an example, but the present invention is not limited to this. The above-described embodiment and modified examples may also be applied to an annular type combustor.

[0124] FIG. 11 is a schematic diagram of the vicinity of a combustor of a gas turbine according to a fourth modification of the first embodiment of the present disclosure. As shown in FIG. 11 , in the annular combustor 10, the inner cylinder 12 and the transition piece 15 are connected in the rotor circumferential direction Dcr, forming a common combustion chamber for each combustor 10. Furthermore, in the annular combustor 10, multiple burners 13 are individually arranged in the common annular combustion chamber. The supply flow rate of compressed air A to each burner 13 depends on the difference between the upstream and downstream pressures of the burner. The lower the downstream pressure, the larger the flow rate of compressed air A to the burner. Since the annular combustor 10 shares a common combustion chamber, the downstream pressure setting value of the burners 13 is the same for all burners 13. However, the expansion work generated by each burner 13 varies transiently, causing transient differences in the downstream pressures of adjacent burners. Therefore, as in the case of the annular cylindrical combustor 10, a partition plate 20 is arranged in the casing 5 as shown in FIG. 11 to separate the air introduction passage F2 through which compressed air A flows for each burner 13. The partition plate 20 may be inclined with respect to the meridian plane of the annular combustor 10 .

[0125] As a result, even in the gas turbine 1 having the annular combustor 10, it is possible to suppress unevenness in the supply amount of compressed air A and suppress combustion oscillation.

[0126] <Second embodiment> Next, a gas turbine 1 according to a second embodiment of the present disclosure will be described. Components common to the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0127] In conventional technology, a cylindrical cooling channel cover is sometimes placed around the outer periphery of a combustor for the purpose of cooling the combustor. A portion of the air passing through the gap (cooling channel) between the cooling channel cover and the outer periphery of the combustor passes through a cooling air inlet provided in the combustor's inner casing and flows into the combustor (inner casing). In this configuration, if combustion oscillation occurs, the pressure of the combustion oscillation due to the cooling air inlet may propagate to the air introduction channel and amplify the combustion oscillation. Because the size of the cooling air inlet is small compared to the flow area of ​​the air introduction channel, low-frequency combustion oscillations of around 100 Hz are unlikely to propagate. It is expected that the amplification of combustion oscillations will be significant in the high-frequency range on the order of kilohertz. To suppress high-frequency combustion oscillations, it is desirable to isolate the cooling air inlet from the air introduction channel.

[0128] Furthermore, in order to increase the length of the flow path in terms of inertia, it is desirable to reduce the flow path area of ​​the air introduction path. However, reducing the flow path area increases the flow velocity, which increases pressure loss and ultimately may reduce the efficiency of the combustor. Furthermore, the cooling flow path in the prior art has high flow resistance due to the presence of internal structures (such as structures provided on the outer circumferential surface of the combustor). Therefore, in this embodiment, the air introduction path is provided separate from the existing cooling flow path to suppress pressure loss.

[0129] FIG. 12 is a cross-sectional view taken along the rotor axis, illustrating a schematic configuration of a combustor and its surroundings of a gas turbine according to a second embodiment of the present disclosure. As shown in FIG. 12 , the gas turbine 1 according to this embodiment is provided with an annular air introduction passage F3, instead of the air introduction passage F2 according to the first embodiment, which is defined by a first cylindrical portion 30 that surrounds the combustor 10 and a second cylindrical portion 31 that surrounds the first cylindrical portion 30, and which introduces compressed air A in the casing 5 into the combustor 10.

[0130] Furthermore, a portion of the compressed air A flows through a gap between the first cylindrical portion 30 and the outer peripheral surface of the combustor 10 (the inner cylinder 12 and the transition piece 15), which functions as a cooling flow path 32 that cools the outer peripheral surface of the combustor 10. A cooling air inlet 33 that communicates with the interior of the inner cylinder 12 is provided on the downstream side of the cooling flow path 32 (the base end side Dcb of the combustor 10), and the compressed air A that has passed through the cooling flow path 32 flows from the cooling air inlet 33 into the interior of the combustor 10 (the inner cylinder 12).

[0131] As described above, the gas turbine 1 according to this embodiment is defined by the first cylindrical section 30 that surrounds the combustor 10 and the second cylindrical section 31 that surrounds the first cylindrical section 30, and is provided with an annular air introduction passage F3 that introduces compressed air A in the casing 5 into the combustor 10.

[0132] In this way, since the outer peripheral surface of the combustor 10 is covered by the first cylindrical portion 30, there is no internal structure within the air introduction path F3 that would obstruct the flow of the compressed air A. This allows the compressed air A to flow smoothly within the air introduction path F3.

[0133] Furthermore, the air introduction passage F3 is isolated from the cooling passage 32 by the first cylindrical portion 30. This makes it possible to suppress the expansion of combustion oscillation by the cooling air inlet 33 of the cooling passage 32.

[0134] <Third embodiment> Next, a gas turbine 1 according to a third embodiment of the present disclosure will be described. Components common to the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0135] FIG. 13 is a cross-sectional view taken along the rotor axis, illustrating a schematic configuration of a combustor and its surroundings of a gas turbine according to a third embodiment of the present disclosure. As shown in FIG. 13, the gas turbine 1 according to this embodiment includes a combustor 10 having an air introduction passage F4 defined by a first wall portion 40 having an L-shaped cross section and a second wall portion 41 having a U-shaped cross section.

[0136] The first wall portion 40 consists of a first plate portion 40a extending from the outer peripheral surface of the combustor 10 and a second plate portion 40b extending from the first plate portion 40a along the outer peripheral surface of the combustor 10 to the axial downstream side Dad of the rotor 4.

[0137] The second wall portion 41 is composed of a third plate portion 41a extending from the inner peripheral surfaces 5a, 5b of the casing 5 along the outer peripheral surface of the combustor 10 to the axial downstream side Dad of the rotor 4, a fourth plate portion 41b extending from the third plate portion 41a toward the outer peripheral surface of the combustor 10, and a fifth plate portion 41c extending from the fourth plate portion 41b along the outer peripheral surface of the combustor 10 to the axial upstream side Dau of the rotor 4.

[0138] The second plate portion 40b of the first wall portion 40 is disposed between the third plate portion 41a and the fifth plate portion 41c of the second wall portion 41 with a gap therebetween.

[0139] The compressed air A in the casing 5 flows into the air introduction passage F4 from between the outer peripheral surface of the combustor 10 and the fifth plate portion 41c of the second wall portion 41 and flows toward the axial upstream side Dau. When the compressed air A that has flowed into the air introduction passage F4 collides with the first plate portion 40a of the first wall portion 40, it changes direction and flows toward the axial downstream side Dad through a passage between the second plate portion 40b of the first wall portion 40 and the fifth plate portion 41c of the second wall portion 41. When the compressed air A collides with the fourth plate portion 41b of the second wall portion 41, it changes direction and flows toward the axial upstream side Dau through a passage between the second plate portion 40b of the first wall portion 40 and the fourth plate portion 41b of the second wall portion 41. In this way, the compressed air A is introduced into the combustor 10 while changing direction inside the air introduction passage F4.

[0140] As described above, the gas turbine 1 according to this embodiment includes the air introduction path F4 in which the flow direction of the compressed air A is changed by the first wall portion 40 and the second wall portion 41. With this configuration, the flow path length of the air introduction path F4 can be increased. This makes it possible to suppress a reduction in the supply flow rate of the compressed air A due to an increase in the internal pressure of the combustor 10, and to suppress combustion oscillation.

[0141] <Fourth embodiment> Next, a gas turbine 1 according to a fourth embodiment of the present disclosure will be described. Components common to the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0142] FIG. 14 is a cross-sectional view taken along the rotor axis, illustrating a schematic configuration of a combustor and its surroundings of a gas turbine according to a fourth embodiment of the present disclosure. 14, the gas turbine 1 according to this embodiment includes a plurality of guide pipes 50. The inside of each guide pipe 50 functions as an air introduction passage F5 that introduces compressed air A into the combustor 10. The guide pipes 50 are provided at intervals in the circumferential direction Dcc of the combustor 10.

[0143] The guide tube 50 has a first opening 51 connected to the inlet of the combustor 10 (the passage between the outer tube 11 and the inner tube 12), and a second opening 52 that opens to the axially downstream side Dad of the rotor 4 in the space within the casing 5.

[0144] In this way, by dividing the air introduction passage F5 into a plurality of guide pipes 50, the degree of freedom in arrangement within the casing 5 can be increased.

[0145] Furthermore, the guide tubes 50 may have different lengths, which can reduce the strength of the resonance of the guide tubes 50.

[0146] <Fifth embodiment> Next, a gas turbine 1 according to a fifth embodiment of the present disclosure will be described. Components common to the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0147] In the above-described embodiment, a technique for suppressing combustion oscillation in units of combustors 10 has been described. In the present embodiment, a technique for suppressing combustion oscillation occurring in units of burners 13 in the combustors 10 will be described. Note that, in the present embodiment, an example will be described in which a configuration for suppressing combustion oscillation in units of burners 13 is applied to the configuration of the first embodiment, but the present invention is not limited to this. In other embodiments, the configuration of this embodiment may be applied to each of the modified examples of the first embodiment and the second to fourth modified examples.

[0148] FIG. 15 is a cross-sectional view taken along the combustor axis, illustrating a schematic configuration of a combustor according to a fifth embodiment of the present disclosure. FIG. 16 is a cross-sectional view illustrating a schematic configuration of a combustor according to a fifth embodiment of the present disclosure, as viewed from the combustor axial direction. As shown in Fig. 15, one combustor 10 has multiple burners 13. The multiple burners 13 are each arranged along the combustor axis Ac. Each burner 13 includes a fuel supply unit 131 that supplies fuel F, a nozzle 132 that ejects the fuel from its tip, and a nozzle cylinder 133 that concentrically surrounds the nozzle 132.

[0149] Moreover, the combustor 10 according to this embodiment further includes a burner partition plate 60 extending along the axial direction Dc of the combustor 10 between adjacent burners 13 and dividing the outlet space 12b of the air introduction passage F2 in the inner cylinder 12 into independent compartments for each of the plurality of burners 13.

[0150] 16, the burner partition plates 60 are provided between the main burners 13b arranged in the circumferential direction Dcc. In addition, the burner partition plates 60 are provided between the pilot burner 13a and the main burners 13b so as to surround the pilot burner 13a.

[0151] The frequency of combustion oscillation in the combustor 10 is on the order of 100 Hz. In contrast, the frequency of combustion oscillation in the burner 13 is on the order of kHz. This depends on the difference in size between the two.

[0152] By providing the burner partition plate 60 in this way and separating the introduction paths of the compressed air A for the multiple burners 13 belonging to one combustor 10, each burner 13 has its own independent inertia of compressed air. As a result, when the pressure of a certain burner 13 rises transiently, the degree to which the compressed air is diverted to other burners 13 due to the inertia of the compressed air of each burner 13 can be reduced.

[0153] As mentioned above, it is known that an abnormal combustion called flashback occurs when the compressed air A decreases. Since flashback occurs first in the burner 13 with the smallest flow rate of compressed air A, making the compressed air A of the burner 13 independent of variations in the pressure of the burner 13 is effective in preventing flashback.

[0154] <Modification 1 of the Fifth Embodiment> Next, a gas turbine 1 according to a first modification of the fifth embodiment of the present disclosure will be described. Components common to the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0155] FIG. 17 is a cross-sectional view taken along the combustor axis, illustrating a schematic configuration of a combustor according to a modification of the fifth embodiment of the present disclosure. As shown in FIG. 17, in the combustor 10 according to this modification, a burner partition plate 60 is provided with burner communication holes 61 that communicate with adjacent sections of the outlet space 12b.

[0156] The burner communication hole 61 is formed by attaching a material that provides flow resistance, such as punched metal, to the burner partition plate 60 .

[0157] When the pressure of one burner 13 becomes higher than that of the other burners 13, a flow occurs in the burner communication holes 61 due to the bypass of compressed air. If flow resistance is provided to the burner communication holes 61, the bypass flow acts as a damping force, thereby suppressing pressure fluctuations. If the pressures of all the burners 13 belonging to one combustor 10 vibrate in the same phase and with the same amplitude, no pressure difference occurs in the burner partition plate 60. Therefore, no damping force is obtained. In this case, vibration occurs on a combustor 10-by-combustor basis, and the configurations of the first to fourth embodiments are used to address this. This modified example is effective against and reduces combustion vibrations between multiple burners 13 inside one combustor 10.

[0158] Sixth Embodiment Next, a gas turbine 1 according to a sixth embodiment of the present disclosure will be described. Components common to the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0159] FIG. 18 is a cross-sectional view taken along the combustor axis, illustrating a schematic configuration of a combustor according to a sixth embodiment of the present disclosure. As shown in FIG. 18, the combustor 10 according to this embodiment has a fuel supply pipe 134 that communicates with each of the plurality of burners 13 and distributes and supplies fuel F to each burner 13.

[0160] In the above-described first to fifth embodiments, a technique for suppressing combustion oscillation by maintaining a constant supply flow rate of compressed air A to the combustor 10 has been described. In the present embodiment, a configuration for suppressing combustion oscillation by applying a similar technique to fuel supply will be described.

[0161] Combustor pressure p B is the downstream pressure for the fuel supply pipe, so the combustor pressure p BAs the flow rate of fuel supply increases, it decreases. In this embodiment, the degree of this decrease is made greater than the decrease in the supply of compressed air A, thereby suppressing combustion oscillation. To achieve this, the equivalent length of the flow path for the inertia of the fuel supply pipe is made shorter than the equivalent length of the flow path of the air introduction passage F2. Specifically, as shown in FIG. 18, a fuel supply pipe 134 common to multiple burners 13 is provided, and fuel F is distributed from the fuel supply pipe 134 to each burner 13, thereby increasing the flow path area per outer diameter.

[0162] In this way, by having a common fuel supply pipe 134 for multiple burners 13, if the pressure in the combustor 10 increases, the fuel supply to the burners 13 is reduced without delay, and the pressure increase is resolved, thereby suppressing combustion oscillation.

[0163] Seventh Embodiment Next, a gas turbine 1 according to a seventh embodiment of the present disclosure will be described. Components common to the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0164] FIG. 19 is a cross-sectional view taken along the combustor axis, illustrating a schematic configuration of a combustor according to a seventh embodiment of the present disclosure. FIG. 20 is a cross-sectional view illustrating a schematic configuration of a combustor according to a seventh embodiment of the present disclosure, as viewed from the combustor axial direction. As shown in FIGS. 19 and 20, the combustor 10 according to this embodiment has fuel distribution pipes 135 that communicate with each of the plurality of burners 13 and allow the plurality of burners 13 to distribute fuel F among each other.

[0165] In the above-described first to fifth embodiments, a technique for suppressing combustion oscillation by maintaining a constant supply flow rate of compressed air A to the combustor 10 has been described. In the present embodiment, a configuration for suppressing combustion oscillation by applying a similar technique to fuel supply will be described.

[0166] Combustor pressure p B is the downstream pressure for the fuel supply pipe, so the combustor pressure p BIn this embodiment, the degree of this reduction is made greater than the reduction in the supply of compressed air A, thereby suppressing combustion oscillation. B 19 and 20, the fuel supply pipes of the plurality of burners 13 are connected by a fuel flow pipe 135, and the combustor pressure p B The high burner 13 generates a combustor pressure p B By distributing fuel F to the burner 13 with low pressure without delay, the combustor pressure p B Reduce the combustion of the burner 13 where the burner pressure p B The combustion of the burner 13 with a low temperature is increased to make the combustion of the plurality of burners 13 uniform.

[0167] In this way, by having the fuel distribution pipe 135 common to the plurality of burners 13, even if an imbalance in pressure occurs in the combustor 10, it is resolved without delay, and combustion oscillation can be suppressed.

[0168] As described above, several embodiments of the present invention have been described, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as defined in the claims, as well as in the scope and spirit of the invention.

[0169] <Additional Notes> The gas turbine described in the above embodiment can be understood, for example, as follows.

[0170] (1) According to a first aspect of the present disclosure, a gas turbine (1) includes a rotor (4) rotatable about an axis, a casing (5) circumferentially covering the rotor (4) and having an annular space therein, a compressor (2) that generates high-pressure compressed air by compressing external air and sends the compressed air into the casing (5), a plurality of combustors (10) arranged at equal intervals in the casing (5) in the circumferential direction of the rotor (4), and that combust fuel with the compressed air taken in from the casing (5) to generate combustion gas, a turbine (3) driven by the combustion gas, a partition plate (20) that divides the space in the casing (5) in the circumferential direction of the rotor (4), and an air introduction passage (F2) that is defined by inner surfaces (5a, 5b) of the casing (5) and introduces the compressed air in the casing (5) into the combustor (10).

[0171] With this configuration, the gas turbine can prevent compressed air in the casing from diverting from one combustor to another combustor when the internal pressure of that combustor rises. This prevents an increase or decrease in the flow rate of compressed air supplied to each combustor due to fluctuations in combustor pressure. Furthermore, since a decrease in the amount of compressed air supplied to a combustor with a rise in internal pressure can be prevented, combustion oscillation and flashback in that combustor can be suppressed.

[0172] (2) According to a second aspect of the present disclosure, in the gas turbine (1) according to the first aspect, the partition plate (20) is provided at the middle of each of the plurality of combustors (10).

[0173] As a result, the gas turbine can have an independent air introduction passage for each combustor, and therefore, even if the internal pressures of the combustors are different, it is possible to suppress differences in the flow rates of compressed air supplied to the combustors, making it possible to more reliably suppress combustion oscillation.

[0174] (3) According to a third aspect of the present disclosure, in the gas turbine (1) according to the first or second aspect, a baffle plate (21) for diverting compressed air is provided inside the air introduction passage (F2).

[0175] This configuration makes it possible to increase the flow path length of the air introduction passage (increase the equivalent length in terms of inertia), thereby suppressing a decrease in the supply flow rate of compressed air due to an increase in the internal pressure of the combustor and suppressing combustion oscillation.

[0176] (4) According to a fourth aspect of the present disclosure, in the gas turbine (1) according to the second or third aspect, the partition plate (20) is provided with a communication hole (22) that connects the air introduction passages (F2) adjacent to each other in the circumferential direction.

[0177] With this configuration, the bypass flow of compressed air acts as a damping force, thereby suppressing pressure fluctuations.

[0178] (5) According to a fifth aspect of the present disclosure, in the gas turbine (1) according to any one of the second to fourth aspects, a compressor outlet flow path (F1) is connected to the casing (5) radially inside the rotor (4), and the partition plate (20) extends to the compressor outlet flow path (F1) in the radial direction of the rotor (4) to divide the compressor outlet flow path (F1) into a plurality of compartments in the circumferential direction of the rotor (4).

[0179] With this configuration, the length of the air flow passage of each combustor can be extended by the length of the compressor outlet flow path, thereby suppressing a reduction in the supply flow rate of compressed air due to an increase in the internal pressure of the combustor and further enhancing the effect of suppressing combustion oscillation.

[0180] (6) According to a sixth aspect of the present disclosure, a gas turbine (1) includes a rotor (4) rotatable about an axis, a casing (5) circumferentially covering the rotor (4) and having an annular space therein, a compressor (2) that generates high-pressure compressed air by compressing external air and sends the compressed air into the casing (5), a plurality of combustors (10) arranged at equal intervals in the circumferential direction of the rotor (4) inside the casing (5) and that combust fuel with the compressed air taken in from the casing (5) to generate combustion gas, a turbine (3) driven by the combustion gas, and an annular air introduction passage (F3) that is defined by a first cylindrical portion (30) surrounding the combustor (10) and a second cylindrical portion (31) surrounding the first cylindrical portion (30) and that introduces the compressed air in the casing (5) into the combustor (10).

[0181] In this way, because the outer peripheral surface of the combustor is covered by the first cylindrical portion, there are no internal structures in the air introduction passage that would obstruct the flow of compressed air, allowing the compressed air to flow smoothly within the air introduction passage.

[0182] (7) According to a seventh aspect of the present disclosure, a gas turbine (1) includes a rotor (4) rotatable about an axis, a casing (5) circumferentially covering the rotor (4) and having an annular space therein, a compressor (2) that generates high-pressure compressed air by compressing external air and sends it into the casing (5), a plurality of combustors (10) arranged at equal intervals in the casing (5) circumferentially around the rotor (4), that combust fuel with the compressed air taken in from the casing (5) to generate combustion gas, a turbine (3) driven by the combustion gas, and an air introduction passage (F4) that introduces the compressed air in the casing (5) into the combustors. The air introduction passage (F4) is defined by a first wall portion (40) having an L-shaped cross section, which includes a first plate portion (40a) extending from the outer peripheral surface of the combustor (10) and a second plate portion (40b) extending from the first plate portion (40a) to the downstream side in the axial direction of the rotor (4); and a second wall portion (41) having a U-shaped cross section, which includes a third plate portion (41a) extending from the inner peripheral surface (5a, 5b) of the casing (5) to the downstream side in the axial direction of the rotor (4), a fourth plate portion (41b) extending from the third plate portion (41a) toward the outer peripheral surface of the combustor (10), and a fifth plate portion (41c) extending from the fourth plate portion (41b) to the upstream side in the axial direction of the rotor (4). The second plate (40b) of the first wall (40) is disposed between the third plate (41a) and the fifth plate (41c) of the second wall (41).

[0183] This configuration allows the length of the air introduction passage to be increased, thereby preventing a decrease in the supply flow rate of compressed air due to an increase in the internal pressure of the combustor, and suppressing combustion oscillation.

[0184] (8) According to an eighth aspect of the present disclosure, a gas turbine (1) includes a rotor (4) rotatable about an axis, a casing (5) circumferentially covering the rotor (4) and having an annular space therein, a compressor (2) that generates high-pressure compressed air by compressing external air and sends it into the casing (5), a plurality of combustors (10) arranged at equal intervals in the circumferential direction of the rotor (4) inside the casing (5) and that combust fuel with the compressed air taken in from the casing (5) to generate combustion gas, a turbine (3) driven by the combustion gas, and an air introduction passage (F5) defined by a plurality of guide pipes (50) having a first opening (51) connected to an inlet of the combustor (10) and a second opening (52) that opens axially downstream of the rotor (4) in the space inside the casing (5).

[0185] In this way, by dividing the air introduction passage into a plurality of guide pipes, the degree of freedom in arrangement within the casing can be increased.

[0186] (9) According to a ninth aspect of the present disclosure, in the gas turbine (1) according to any one of the first to eighth aspects, the combustor (10) includes an inner cylinder (12) to which compressed air is supplied from the casing (5) through an air introduction passage, a plurality of burners (13) extending in the axial direction of the combustor (10) and spaced apart along the inner circumference of the inner cylinder (12), the burners (13) having nozzles (132) that eject fuel from their tips and nozzle cylinders (133) that concentrically surround the nozzles (132), and a burner partition plate (60) extending along the axial direction of the combustor (10) between adjacent burners (13) and dividing an outlet space (12b) of the air introduction passage in the inner cylinder (12) into independent compartments for each of the plurality of burners (13).

[0187] By providing a burner partition plate in this way and separating the compressed air introduction paths for multiple burners belonging to one combustor, each burner has its own independent compressed air inertia. This makes it possible to reduce the extent to which compressed air bypasses other burners due to the inertia of the compressed air of each burner when the pressure of one burner rises transiently.

[0188] (10) According to a tenth aspect of the present disclosure, in the gas turbine (1) according to the ninth aspect, the burner partition plate (60) is provided with a burner communication hole (61) that communicates with adjacent compartments.

[0189] When the pressure of one burner becomes higher than that of the other burners, a flow occurs in the burner connection hole due to the bypass of compressed air. By providing flow resistance to the burner connection hole, the bypass flow acts as a damping force, thereby suppressing pressure fluctuations.

[0190] (11) According to an eleventh aspect of the present disclosure, in the gas turbine (1) according to any one of the first to eighth aspects, the combustor (10) includes an inner cylinder (12) to which compressed air is supplied from the casing (5) through an air introduction passage, a plurality of burners (13) extending in the axial direction of the combustor (10) and spaced apart along the inner circumference of the inner cylinder (12), the burners (13) having nozzles (132) that eject fuel from the tips and nozzle cylinders (133) that concentrically surround the nozzles (132), and fuel supply pipes (134) connected to each of the plurality of burners (13) and distributing and supplying fuel to the burners (13).

[0191] In this way, by providing a common fuel supply pipe for a plurality of burners, combustion oscillation can be suppressed even when there is a bias in the pressure in the combustor.

[0192] (12) According to a twelfth aspect of the present disclosure, in the gas turbine (1) according to any one of the first to eighth aspects, the combustor (10) includes an inner cylinder (12) to which compressed air is supplied from the casing (5) through an air introduction passage, a plurality of burners (13) extending in the axial direction of the combustor (10) and spaced apart along the inner circumference of the inner cylinder (12), the burners (13) having nozzles (132) that eject fuel from the tips and nozzle cylinders (133) that concentrically surround the nozzles (132), and a fuel distribution pipe (135) that communicates with the plurality of burners (13) and allows the fuel supplied to each of the burners (13) to circulate between the burners (13).

[0193] In this way, by having a common fuel distribution pipe for a plurality of burners, any imbalance in pressure in the combustor is resolved without delay, thereby suppressing combustion oscillation. [Explanation of symbols]

[0194] 1. Gas turbine 2 Compressor 3 Turbine 4 rotors 5 Casing 10 Combustor 11 Outer cylinder 12 Inner cylinder 13 Burner 15 Tailpiece 20 Divider 21, 21a, 21b, 21c Baffle plates 22 Connection hole 30 First cylinder part 31 Second cylinder part 32 Cooling channel 33 Cooling air inlet 40 1st wall section 41 Second wall section 50 Guide tube 60 Burner partition plate 61 Burner connection hole 131 Fuel supply section 132 nozzles 133 Nozzle cylinder 134 Fuel supply piping 135 Fuel distribution piping F1 Compressor outlet flow path F2, F3, F4, F5 air intake passages

Claims

1. a rotor rotatable about an axis; a casing that circumferentially covers the rotor and has an annular space therein; a compressor that compresses external air to generate high-pressure compressed air and delivers the compressed air into the casing; a plurality of combustors arranged at equal intervals in the circumferential direction of the rotor within the casing, the combustors combusting the compressed air taken in from the casing with fuel to generate combustion gas; a turbine driven by the combustion gas; an air introduction passage defined by a partition plate that divides the space within the casing in a circumferential direction of the rotor and an inner circumferential surface of the casing, the air introduction passage introducing the compressed air within the casing into the combustor; Equipped with a compressor outlet flow path is connected to the casing on the radially inner side of the rotor, the partition plate extends to the compressor outlet passage in a radial direction of the rotor and divides the compressor outlet passage into a plurality of sections in a circumferential direction of the rotor; each of the plurality of compartments in the compressor outlet flow path is formed as an independent compartment surrounded by a wall surface of the compressor outlet flow path and the partition plate so that the compressed air flowing therethrough does not flow into another compartment adjacent in the circumferential direction; Gas turbine.

2. The partition plate is provided between the plurality of combustors. The gas turbine of claim 1 .

3. A baffle plate for diverting the compressed air is provided inside the air introduction passage.

3. A gas turbine according to claim 1 or 2.

4. The partition plate is provided with a communication hole that connects the air introduction passages adjacent in the circumferential direction.

4. A gas turbine according to claim 2 or 3.

5. The combustor includes: an inner cylinder to which the compressed air is supplied from the casing through the air introduction passage; a burner extending in the axial direction of the combustor and provided at intervals along an inner circumference of the inner cylinder, the burner including a plurality of nozzles for ejecting fuel from a tip thereof, and a nozzle cylinder concentrically surrounding the nozzles; a burner partition plate extending along the axial direction of the combustor between adjacent burners and dividing an outlet space of the air introduction passage in the inner cylinder into independent sections for each of the plurality of burners; having A gas turbine according to any one of claims 1 to 4.

6. The burner partition plate is provided with a burner communication hole that communicates with the adjacent compartments. The gas turbine of claim 5.

7. The combustor includes: an inner cylinder to which the compressed air is supplied from the casing through the air introduction passage; a burner extending in the axial direction of the combustor and provided at intervals along an inner circumference of the inner cylinder, the burner including a plurality of nozzles for ejecting fuel from a tip thereof, and a nozzle cylinder concentrically surrounding the nozzles; a fuel supply pipe connected to each of the plurality of burners and distributing and supplying the fuel to the burners; having A gas turbine according to any one of claims 1 to 4.

8. The combustor includes: an inner cylinder to which the compressed air is supplied from the casing through the air introduction passage; a burner extending in the axial direction of the combustor and provided at intervals along an inner circumference of the inner cylinder, the burner including a plurality of nozzles for ejecting fuel from a tip thereof, and a nozzle cylinder concentrically surrounding the nozzles; a fuel distribution pipe that communicates with the plurality of burners and allows fuel supplied to each of the burners to be distributed among the burners; having A gas turbine according to any one of claims 1 to 4.

9. A rotor rotatable about an axis; a casing that circumferentially covers the rotor and has an annular space therein; a compressor that compresses external air to generate high-pressure compressed air and delivers the compressed air into the casing; a plurality of combustors arranged at equal intervals in the circumferential direction of the rotor within the casing, the combustors combusting the compressed air taken in from the casing with fuel to generate combustion gas; a turbine driven by the combustion gas; an air introduction passage defined by a partition plate that divides the space within the casing in a circumferential direction of the rotor and an inner circumferential surface of the casing, the air introduction passage introducing the compressed air within the casing into the combustor; Equipped with The combustor includes: an inner cylinder to which the compressed air is supplied from the casing through the air introduction passage; a burner extending in the axial direction of the combustor and provided at intervals along an inner circumference of the inner cylinder, the burner including a plurality of nozzles for ejecting fuel from a tip thereof, and a nozzle cylinder concentrically surrounding the nozzles; a fuel distribution pipe that communicates with the plurality of burners and allows fuel supplied to each of the burners to be distributed among the burners; having Gas turbine.

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