Combustion chamber and gas turbine, which it features

Abstract

Combustion chamber, comprising: a fuel nozzle (54) for injecting fuel; a combustion liner (80) surrounding a combustion chamber (82) for burning the fuel, the combustion liner (80) having an inner passage (100) with an outlet (102) communicating with the combustion chamber (4); and a fuel / air mixture line (200) for introducing a fuel / air mixture (H) containing the fuel and compressed air into the inner passage (100), wherein the fuel / air mixture line (200) is connected to an inlet of the inner passage (100) of the combustion liner (80), wherein the combustion liner (80) is designed to be cooled by the fuel / air mixture (H) flowing through the inner passage (100); characterized by the fact that a concentration of the fuel (F) in the fuel / air mixture line (200) is lower than or equal to a flammability limit concentration.

Description

TECHNICAL FIELD

[0001] This disclosure relates to a combustor and a gas turbine having the same. BACKGROUND

[0002] In a combustion chamber used in a gas turbine, hot parts must be cooled reliably.

[0003] For example, JP 2012-77660 A discloses a combustion chamber configured such that a portion of compressed air generated by a compressor is extracted, and the extracted air is pressurized and then introduced into a cooling air passage formed in a combustion liner (English: "combustion liner", German also: "combustion chamber lining", "combustion chamber wall") to cool the combustion liner by means of the extracted air.

[0004] JP 2011-153815 A further discloses a combustion chamber in which the air flowing adjacent to a diffuser wall is extracted and a fuel / air mixture formed by injecting fuel into the extracted air is supplied to a combustion liner on the downstream side of a fuel nozzle, although this is not intended to cool the combustion liner.

[0005] JP 2000-46 333 A and US 6 209 325 B1 describe a combustion chamber having the features of the preamble of claim 1. PRESENTATIONProblems to be solved

[0006] However, when a portion of the compressed air supplied from the compressor is used to cool the combustion liner, as in JP 2012-77660 A, the amount of compressed air supplied to the fuel nozzle outlet is reduced by the amount of compressed air used to cool the combustion liner, so that the fuel / air ratio near the fuel nozzle outlet increases. As a result, the flame temperature near the fuel nozzle outlet rises, and NO x , which is an air pollutant, can be generated.

[0007] In view of the above, an object of some embodiments is to provide a combustion chamber and a gas turbine having the combustion chamber, whereby it is possible to suppress the increase in flame temperature in the vicinity of the fuel nozzle outlet and to suppress the generation of NO x to reduce. Solving the problems

[0008] This object is achieved by a combustion chamber having the features of claim 1 and a gas turbine having the features of claim 11. Preferred embodiments follow from the remaining claims. (1) A combustion chamber according to at least one embodiment of the present invention includes: a fuel nozzle for injecting fuel; a combustion liner surrounding a combustion chamber for burning the fuel and having an internal passage with an outlet communicating with the combustion chamber; and a fuel-air mixture line connected to an inlet of the internal passage of the combustion liner for introducing a fuel-air mixture containing the fuel and compressed air into the internal passage. The combustion liner is configured to be cooled by the fuel-air mixture flowing through the internal passage.

[0009] In the above configuration (1), the fuel-air mixture generated by mixing the compressed air and the fuel is used as a coolant for cooling the combustion liner. Accordingly, compared with the case where the coolant for cooling the combustion liner is only compressed air, the amount of fuel supplied to the fuel nozzle outlet and the fuel-air ratio at the fuel nozzle outlet are relatively small. As a result, it is possible to suppress the increase in flame temperature in the vicinity of the fuel nozzle outlet and thus prevent the generation of NO. x to reduce.

[0010] If the coolant for cooling the combustion liner is only compressed air, the progress of the combustion reaction may be hindered by mixing the coolant (compressed air) containing no fuel, and the CO concentration in the combustion gas discharged from the combustion chamber may increase. In this regard, in the above configuration (1), because the fuel-air mixture supplied from the internal passage of the combustion liner into the combustion chamber contains fuel, the combustion reaction in the combustion chamber is promoted, and the CO concentration in the combustion gas discharged from the combustion chamber is reduced. This is useful during low-load operation where the generation of unburned CO is likely.

[0011] (2) In some embodiments, the combustion chamber in the above configuration (1) may include: a compressed air passage through which the compressed air flows; and a fuel supply part arranged on the compressed air passage for supplying the fuel to the compressed air flowing through the compressed air passage. The fuel-air mixture passage may be configured such that the fuel-air mixture containing the fuel supplied from the fuel supply part and the compressed air flowing through the compressed air passage is introduced into the internal passage.

[0012] In the above configuration (2), the fuel supply part supplies fuel to the compressed air supplied from the compressed air line, and the fuel-air mixture containing the compressed air and the fuel is generated. When the thus-obtained fuel-air mixture is used to cool the combustion liner based on the principle described in (1) above, it is possible to suppress the increase in the flame temperature in the vicinity of the fuel nozzle outlet, thus preventing the generation of NO, compared with the case where the coolant for cooling the combustion liner is only the compressed air. x to reduce.

[0013] (3) In some embodiments, in the above configuration (2), the compressed air line may be configured to extract the compressed air from an intermediate stage of a compressor of a gas turbine having the combustor or a casing interior of the gas turbine.

[0014] In the above configuration (3), the combustion liner can be cooled using the compressed air generated by the compressor of the gas turbine. Furthermore, when the fuel-air mixture obtained by adding the fuel to the extracted compressed air is used as a coolant for cooling the combustion liner based on the above-described item (1), it is possible to suppress the rise in the flame temperature in the vicinity of the nozzle outlet and thus prevent the generation of NO. x compared to the case where the coolant for cooling the combustion liner is only compressed air.

[0015] (4) In some embodiments, in the above configuration (2) or (3), the fuel supply member may have the shape of an airfoil including: a leading edge portion positioned on an upstream side in a flow direction of the compressed air in the compressed air passage; and a trailing edge portion positioned on a downstream side of the leading edge portion in the flow direction, and including a fuel injection hole for injecting the fuel downstream.

[0016] With the above configuration (4), the formation of a low-flow velocity region of the fuel-containing compressed air (fuel-containing air) at the downstream side of the trailing edge portion of the fuel supply part can be prevented. As a result, it is possible to prevent the ignition of the fuel-containing air in the compressed air line.

[0017] (5) In some embodiments, in any of the above configurations (2) to (4), the combustion chamber may include a booster compressor arranged on the compressed air line.

[0018] With the above configuration (5), the air supplied to the compressed air line can be pressurized. As a result, even if air is supplied to the compressed air line at a low pressure, the air in the compressed air line can be pressurized to a pressure suitable for supplying the fuel / air mixture to the internal passage of the combustion liner.

[0019] (6) In some embodiments, in any of the above configurations (2) to (5), the combustion chamber may comprise a cooler arranged on the compressed air line to cool the compressed air.

[0020] In the above configuration (6), the compressed air can be cooled by the cooler. As a result, compressed air can be generated at a temperature that is more suitable for cooling.

[0021] (7) In some embodiments, in any one of the above configurations (1) to (6), the fuel / air mixture line may comprise a blade ring cooling line extending inside a blade ring of a gas turbine having the combustion chamber.

[0022] In the above embodiment (7), not only the combustion liner but also the blade ring of the gas turbine can be cooled using the fuel / air mixture as a coolant.

[0023] (8) In some embodiments, in the above configuration (7), the fuel-air mixture passage may include a bypass passage that bypasses the blade ring cooling passage, and the combustion chamber may further include a passage switching valve configured to switch a passage through which the fuel-air mixture flows between the blade ring cooling passage and the bypass passage.

[0024] In the above configuration (8), the blade ring cooling line and the bypass line can be switched. As a result, it is possible, for example, to select whether to use the blade ring cooling line or the bypass line according to the operating state of the gas turbine, and effectively use the fuel-air mixture as a coolant for cooling.

[0025] (9) According to the invention, a concentration of the fuel in the fuel / air mixture line is less than or equal to a flammability limit concentration.

[0026] This makes it possible to prevent the ignition of the fuel / air mixture in a space other than the combustion chamber inside the combustion liner. Furthermore, it is possible to prevent the local temperature of the flames in the vicinity of the position where the fuel / air mixture is supplied to the combustion chamber from rising when the fuel / air mixture is introduced into the combustion chamber and burned. As a result, it is possible to prevent the generation of NO. x in the combustion liner.

[0027] (10) In some embodiments, in any of the above configurations, the outlet of the inner passage may be positioned downstream of a downstream end of the fuel nozzle in an axial direction of the combustion liner.

[0028] As described above, the fuel / air mixture supplied to the combustion chamber after passing through the internal passage of the combustion liner contains fuel.

[0029] In the above configuration (10), because the supply position of the fuel-containing air-fuel mixture to the combustion chamber (i.e., the outlet position of the inner passage of the combustion liner) is set on the downstream side of the downstream end of the fuel nozzle in the axial direction of the combustion liner, the fuel contained in the air-fuel mixture does not cause an increase in the air-fuel ratio in the vicinity of the fuel nozzle outlet. As a result, based on the principle described in (1) above, it is possible to reduce the combustion temperature of the flame in the vicinity of the fuel nozzle outlet and thus reduce the generation of NO. xcompared to the case where the coolant for cooling the combustion liner is only compressed air.

[0030] (11) In some embodiments, the inner passage in any one of the above configurations (1) to (10) may include a plurality of straight passages extending in an axial direction of the combustion liner.

[0031] In the above configuration (11), it is possible to cool the combustion liner more efficiently because the fuel / air mixture serving as a coolant flows through the plurality of internal passages.

[0032] (12) A gas turbine according to at least one embodiment of the present invention comprises: a compressor for generating compressed air; the combustor described in any one of the above aspects (1) to (11); and a turbine configured to be driven by a combustion gas from the combustor.

[0033] In the above configuration (12), compared with the case where the coolant for cooling the combustion liner is only the compressed air, it is possible, based on the principle described in (1) above, to reduce the combustion temperature of the flame in the vicinity of the fuel nozzle outlet and thus to reduce the generation of NO x to reduce. Beneficial effects

[0034] According to some embodiments of the present invention, it is possible to suppress an increase in flame temperature in the vicinity of the fuel nozzle outlet and to prevent the generation of NO x to reduce. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of the configuration of a gas turbine according to an embodiment of the present invention. Fig. 2 is a cross-sectional view of a combustion chamber according to an embodiment of the present invention. Fig. 3 is a partial cross-sectional view of a portion of a combustion liner according to an embodiment of the present invention. Fig. 4 is a schematic diagram showing a configuration example of a cooling system of a combustion liner according to an embodiment of the present invention. Fig. 5A is a schematic perspective view of a fuel supply part according to an embodiment of the present invention, in which the fuel supply part is incorporated into a cooling system of a combustion liner. Fig. 5B is a schematic cross-sectional view of a fuel supply part according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0036] However, the scope of the present invention is not limited to the following embodiments. The dimensions, materials, shapes, relative positions, and the like of components described in the embodiments are intended to be interpreted as illustrative only and do not limit the scope of the present invention.

[0037] Fig. 1 is a schematic diagram of the configuration of a gas turbine 1 according to an embodiment of the present invention.

[0038] As in Fig. As shown in Figure 1, the gas turbine 1 according to one embodiment comprises a compressor 2 for generating compressed air G, a combustion chamber 4 for generating a combustion gas using compressed air G and fuel F, and a turbine 6 configured to be rotated by the combustion gas. The rotating shaft 2 of the compressor 2 and the rotating shaft of the turbine 6 are connected to each other and form a rotor 8 of the Fig. 1. When the turbine 6 is driven by the combustion gas, the rotational force of the turbine 6 is transmitted to the compressor 2 via the rotor 8 to drive the compressor 2. In the case of the gas turbine 1 for power generation, a generator (not shown) is connected to the turbine 6 side or the compressor 2 side of the rotor 8, so that rotational energy of the turbine 6 generates electric power.

[0039] Next, with reference to Fig. 1, the configuration of each part of the gas turbine 1 according to an embodiment is described.

[0040] The compressor 2 comprises a compressor housing 10, an air inlet 12 arranged on the inlet side of the compressor housing 10 for drawing in air, and various vanes arranged in the compressor housing 10. The various vanes include an inlet guide vane 14 arranged adjacent to the air inlet 12, a plurality of stator vanes 16 attached to the compressor housing 10, and a plurality of rotor blades 18 arranged on the rotor 8 such that they alternate with the stator vanes 16. The compressor 2 may comprise further components not shown in the drawings, such as an extraction chamber.

[0041] In the compressor 2, the air drawn from the air inlet 12 flows through the plurality of stator vanes 16 and the plurality of rotor blades 18 to be compressed into compressed air G having a high temperature and high pressure. The compressed air G is supplied from the compressor 2 to the combustion chamber 4 of a later stage.

[0042] The combustion chamber 4 is arranged in a housing 20. As in Fig. As shown in Figure 1, a plurality of combustion chambers 4 can be arranged around the rotor 8. The combustion chamber 4 is supplied with the fuel F and the compressed air generated by the compressor 2 and combusts the supplied fuel F to generate combustion gas, which serves as the working medium of the turbine 6. The turbine 6 of a later stage of the combustion chamber 4 is fed with the generated combustion gas. The specific design of the combustion chamber 4 will be described later.

[0043] The turbine 6 includes a turbine housing 22, a plurality of stator blades 24, and a plurality of rotor blades 26 disposed inside the turbine housing 22, as well as a blade ring 27 disposed radially outside the stator blades 24 to surround the stator blades 24. The stator blades 24 are attached to the turbine housing 22 via the blade ring 27, and the rotor blades 26 are arranged on the rotor 8 such that they alternate with the stator blades 24.

[0044] In the turbine 6, the rotor 8 is driven to rotate as the combustion gas flows through the plurality of stator vanes 24 and the plurality of rotor blades 26. As a result, the generator (not shown) connected to the rotor 8 is driven.

[0045] An exhaust chamber 30 is connected to the downstream side of the turbine housing 22 via an exhaust casing 28. Thus, the turbine 6 is configured such that the combustion gas that has driven the turbine 6 is discharged to the outside through the exhaust casing 28 and the exhaust chamber 30.

[0046] Next, with reference to Fig. 2 to 5A and 5B describe the concrete design of the combustion chamber 4 according to one embodiment.

[0047] Fig. 2 is a cross-sectional view of the combustion chamber 4 according to an embodiment of the present invention. Fig. 3 is a partial cross-sectional view of a portion of a combustion liner 80 according to an embodiment of the present invention. Fig. 4 is a schematic diagram showing a configuration example of a cooling system of the combustion liner 80 according to an embodiment of the present invention. Fig. 5A is a schematic perspective view of a fuel supply part 350 incorporated into the cooling system of a combustion liner 80. Fig. 5B is a schematic cross-sectional view of the fuel supply part 350.

[0048] As in Fig. As shown in Figure 2, the combustion chamber 4 comprises at least one burner (50, 60) and a combustion liner (combustion chamber liner) 80 arranged in a housing interior 40 defined by the housing 20 on the downstream side of the burner (50, 60). Fig. In the embodiment shown in Figure 2, the combustion chamber 4 has a pre-burner 50 and a plurality of premixed burners 60.

[0049] The combustion chamber 4 may include other components, such as a bypass pipe (not shown) to allow the combustion gas to bypass.

[0050] The pre-combustor 50 is a starter (ignition) combustor as a main burner for igniting the premixed burners 60 and has a fuel nozzle 54 connected to a fuel nozzle 52 and a pilot cone 56 arranged downstream of a fuel nozzle 54.

[0051] The plurality of premixed burners 60 are arranged around the precombustor 50. Each premixed burner 60 has a main nozzle 64 (fuel nozzle) connected to a fuel nozzle 62.

[0052] The combustion liner 80 includes a flame tube 46A and a transition piece 46B inserted into a tip end portion of the flame tube 46A. A combustion chamber 82 is formed in a hollow portion located inside the combustion liner 80 and surrounded by the inner peripheral surface of the cylindrical wall constituting the combustion liner 80.

[0053] In the combustion chamber 4 having the above configuration, the compressed air G generated by the compressor 2 is supplied from a housing inlet 42 into the housing interior 40, and is further introduced from the housing interior 40 into the premixed burner 60. After the compressed air G introduced into the premixed burner 60 and the fuel F supplied from the fuel inlet 62 are premixed in the premixed burner, the premixed fuel is injected from the main nozzle 64 into the combustion liner 80.

[0054] Furthermore, the compressed air G introduced from the housing interior 40 to the combustion liner 80 without passing through the premixture burner 60 and the fuel F injected from the fuel nozzle 52 through the fuel nozzle 54 are mixed in the combustion liner 80 to form a fuel-air mixture. The combustion of the fuel-air mixture forms a so-called pilot flame. At this time, the flame (pilot flame) formed by the pre-combustor 50 ignites the premixture injected from the above-described premixture burner 60, and burns stably in the combustion chamber 82 inside the combustion liner 80.

[0055] The combustion gas generated in the combustion chamber 82 passes through the combustion liner 80 and is supplied to the turbine 6, which is arranged on the downstream side in the combustion gas flow.

[0056] The fuel F introduced from the fuel inlet 52 and the fuel inlet 62 may be a gas or a liquid and is not limited to any specific type of fuel. Furthermore, the fuel F supplied to the fuel inlet 52 and the fuel F supplied to the fuel inlet 62 may be different types of fuel F. For example, oil fuel may be supplied to the fuel inlet 52, and gas fuel, such as natural gas, may be supplied to the fuel inlet 62.

[0057] In the combustion chamber 4 having the above configuration, the combustion liner 80 is heated during the operation of the gas turbine 1. Therefore, as shown in the Fig. 2 and Fig. 3, the combustion liner 80 has an internal passage 100 for cooling the combustion liner 80.

[0058] As in Fig. 4, a fuel / air mixture line 200, which will be described later, is connected to the inlet of the internal passage 100. Thus, the fuel / air mixture H, which contains the fuel F and the compressed air G, is supplied from the fuel / air mixture line 200 to the internal passage 100. On the other hand, as shown in the Fig. 2 to 3, the outlet 102 of the inner passage 100 is connected to the combustion chamber 82 inside the combustion liner 80. Accordingly, the fuel / air mixture H, after passing through the inner passage 100 and cooling the combustion liner 80, flows into the combustion chamber 82.

[0059] At this time, when the coolant for cooling the combustion liner 80 is only the compressed air G, since the total amount of the fuel F supplied to the combustion liner 80 is supplied to the outlet of the fuel nozzle 54 and the outlet of the main nozzle 64, the amount of the fuel F supplied to the outlet of the fuel nozzle 54 and the outlet of the main nozzle 64 and the fuel-air ratio at the outlet of the main nozzle 64 and the outlet of the fuel nozzle 54 are relatively high compared with the case where the fuel-air mixture H in which the fuel F (a part of the total amount) is mixed with the compressed air G is used.In view of the above configuration, when the fuel-air mixture H in which the fuel F is mixed with the compressed air G is used as the coolant for cooling the combustion liner 80, compared with the case where the coolant for cooling the combustion liner 80 is only the compressed air G, the amount of fuel F supplied to the outlet of the fuel nozzle 54 and the outlet of the fuel nozzle 64 and the fuel-air ratio (here: ratio of fuel F to compressed air G) at the outlet of the fuel nozzle 54 and the outlet of the main nozzle 64 are relatively small. As a result, the rise of the flame temperature in the vicinity of the outlet of the fuel nozzle 54 and the vicinity of the outlet of the main nozzle 64 is suppressed. It is known that the amount of NO. x, which is generated during the process of fuel combustion, increases as the combustion temperature rises. Therefore, if the increase in the flame temperature in the vicinity of the outlet of the fuel nozzle 54 and the vicinity of the outlet of the main nozzle 64 is suppressed, it is possible to suppress the generation of NO x to reduce.

[0060] The fuel / air mixture H supplied from the fuel / air mixture line 200 to the internal passage 100 may be a mixture of any fuel F and compressed air G generated by the compressor 2 in the housing interior 40. The fuel F contained in the fuel / air mixture H may be the same as or different from the fuel F supplied to the at least one burner (50, 60). Furthermore, as in Fig. 2, the fuel / air mixture H in the internal passage 100 may be in a direction opposite to the flow direction of the combustion gas in the combustion chamber 82. The internal passage 100 may further, as shown in Fig. 2, have a plurality of outlets 102. If the inner passage 100 has a plurality of outlets 102, the outlets 102 may be arranged at different positions in the axial direction of the combustion liner 80.

[0061] The inner passage 100 may, for example, include a linear passage 100a formed inside the cylinder wall constituting the combustion liner 80, although the inner passage 100 is not limited to a specific configuration.

[0062] In the Fig. In the embodiment shown in Figure 3, the inner passage 100 includes a plurality of linear passages 100a arranged circumferentially inside the cylinder wall between the inner peripheral surface and the outer peripheral surface of the combustion liner 80. Each linear passage 100a extends in the axial direction of the combustion liner 80.

[0063] The linear passages 100a may be arranged at equal intervals in the circumferential direction. Providing a plurality of internal passages 100 (linear passages 100a) increases the contact area between the coolant (fuel / air mixture H) flowing through the internal passage 100 and the combustion liner 80, so that the combustion liner 80 can be cooled more efficiently.

[0064] The lengths of the linear passages 100a in the axial direction are not limited to a specific length. The linear passages 100a may have the same length in the axial direction, or may, as shown in Fig. 3, have different lengths. In the Fig. In the example shown in FIG. 3, the outlet 102 of the linear passage 100a, which has a long length, is positioned upstream of the outlet 102 of the linear passage 100a, which has a short length, in the axial direction of the combustion liner 80. In this way, when the outlets 102 of the inner passage 100 are scattered at different locations in the axial direction, the positions where the fuel F contained in the fuel-air mixture H is burned are scattered in the axial direction. As a result, the heat distribution in the combustion chamber 82 is kept uniform in the axial direction, and the combustion vibration of the combustion chamber 4 can be suppressed.

[0065] In the axial direction of the combustion liner 80, the outlet 102 of the inner passage 100 is arranged downstream of a downstream end 55 of the fuel nozzle 54 with respect to the combustion gas flow.

[0066] For example, d ≥ 0.2×L may be satisfied, where L is the total length of the cylindrical portion of the combustion liner 80 at the downstream side of the downstream end 55 of the fuel nozzle 54 (in the case shown in Fig. 2, the section of the combustion liner 80, except for the non-cylindrical portion on the downstream side of the transition piece 46B), and d is the distance between the downstream end 55 of the fuel nozzle 54 and the outlet 102 of the inner passage 100 (if there are multiple outlets 102, the outlet 102 located on the most upstream side in the combustion gas flow) in the axial direction of the combustion liner 80.

[0067] In the above configuration, when the coolant is the fuel-air mixture H including the compressed air G and the fuel F, the fuel F contained in the fuel-air mixture H does not increase the fuel-air ratio in the vicinity of the fuel nozzle 54 because the supply position of the fuel-air mixture H to the combustion chamber 82 (ie, the position of the outlet 102 of the inner passage 100 of the combustion liner 80) is set on the downstream side of the downstream end 55 of the fuel nozzle 54 in the axial direction of the combustion liner 80. As a result, it is possible to reduce the combustion temperature of the flame in the vicinity of the outlet of the fuel nozzle 54 and thus reduce the generation of NO x compared to the case where the coolant for cooling the combustion liner is only compressed air.

[0068] The inlet of the inner passage 100 having the above configuration is connected to the fuel / air mixture line 200 to introduce the fuel / air mixture H containing the fuel F and the compressed air G into the inner passage 100, as shown in Fig. 4 shown.

[0069] As in Fig. As shown in Figure 4, the fuel / air mixture line 200 may include a blade ring cooling line 210 that extends inside the blade ring 27 of the turbine 6. In this case, the fuel / air mixture H as a coolant first passes through the blade ring cooling line 210 to cool the blade ring 27, then passes through the inner passage 100 to cool the combustion liner 80, and then flows from the outlet 102 of the inner passage 100 into the combustion chamber 82 of the combustion liner 80. With this configuration, the fuel / air mixture H can be used not only to cool the combustion liner 80, but also the blade ring 27 of the gas turbine 1.

[0070] As in Fig. As shown in Figure 4, according to one embodiment, the fuel / air mixture line 200 may include, in addition to the blade ring cooling line 210, a bypass line 220 that bypasses the blade ring cooling line 210. Furthermore, the combustion chamber may include a passage switching valve 230 configured to switch a passage through which the fuel / air mixture flows between the blade ring cooling line 210 and the bypass line 220.

[0071] With the passage switching valve 230, it is possible to select whether the blade ring cooling line 210 or the bypass line 220 is used according to the operating state of the gas turbine 1, and to use the fuel / air mixture H as a coolant for cooling.

[0072] For example, the blade ring 27 is not heated during startup of the gas turbine 1. Therefore, the bypass line 220 can be selected, and the fuel / air mixture can be used only to cool the combustion liner 80. However, at the rated load of the gas turbine 1, the blade ring 27 is heated compared to the time of startup. Therefore, the blade ring cooling line 210 can be selected, and the fuel / air mixture H can be used to cool the combustion liner 80 and the blade ring 27.

[0073] The combustion chamber 4 according to the Fig. The embodiment shown in Figure 4 may further comprise a compressed air line 300 for introducing compressed air G into the fuel / air mixture line 200 and a fuel supply part 350 arranged on the compressed air line 300 for supplying the fuel F to the compressed air G. The fuel supplied from the fuel supply part 350 and the compressed air G flowing through the compressed air line 300 flow into the fuel / air mixture line 200 as a fuel / air mixture H.

[0074] The compressed air line 300 for introducing the compressed air G may further be configured to extract the compressed air from different locations.

[0075] For example, the compressed air G can be obtained from an intermediate stage of the Fig. 1 shown compressor 2, or the compressed air G can be extracted from the housing interior 40, which in Fig. 2 is shown.

[0076] The combustion chamber 4 can furthermore, as in the Fig. 4, a cooler 302 arranged on the compressed air line 300, and a booster compressor 304 arranged on the compressed air line 300. In the exemplary embodiment shown in Fig. In the combustion chamber shown in Figure 4, the booster compressor 304 is arranged downstream of the cooler 302 in the flow direction of the compressed air G. In the combustion chamber 4, the cooler 302 can generate the compressed air at a temperature more suitable for cooling. Furthermore, the booster compressor 304 can pressurize the air in the compressed air line 300 to a pressure suitable for supply to the internal passage 100 of the combustion liner 80 even when low-pressure air, such as ambient air, is supplied to the compressed air line 300.

[0077] The compressed air line 300, the cooler 302, the booster compressor 304, and the fuel supply part 350 can be arranged outside the housing 20. With this configuration, the compressed air G containing the fuel F can be introduced from the compressed air line 300 outside the housing 20 to the fuel / air mixture line 200 inside the housing 20.

[0078] Alternatively, the fuel supply part 350 can be arranged on the fuel / air mixture line 200 inside the housing 20. For example, the fuel supply part 350 can be arranged downstream of the blade ring cooling line 210 on the fuel / air mixture line 200. In this case, the fuel F is supplied to the compressed air G after cooling the blade ring 27.

[0079] Fig. 5A is a schematic perspective view of the fuel supply part 350. Fig. 5B is a schematic cross-sectional view of the fuel supply part 350.

[0080] The overall design of the combustion chamber 4 has been described. Next, with reference to Fig. 5A and Fig. 5B, the configuration of the fuel supply part 350 of the combustion chamber 4 according to an embodiment of the present invention is described.

[0081] As in Fig. 5A and Fig.5B, the fuel supply part 350 for supplying the fuel F to the compressed air G may have an airfoil shape including: a leading edge portion 352 located on an upstream side in a flow direction of the compressed air G in the compressed air line 300; and a trailing edge portion 354 positioned on a downstream side of the leading edge portion 352 in the flow direction and having a fuel injection hole 360 ​​for injecting the fuel downstream. In such a fuel supply part 350, one surface and the other surface may be symmetrical with respect to the chord connecting the leading edge portion 352 and the trailing edge portion 354. That is, the fuel supply part 350 may be formed in a streamlined shape such that turbulence does not occur at least on the trailing side of the fuel injection hole 360 ​​in the flow direction of the compressed air G, that is,It may be formed of a curve (or a curved surface) that does not generate turbulence even during flow and receives the least resistance from the flow. Specifically, the fuel supply part 350 may have a pointed shape whose cross section is elongated (or thin) along the flow direction of the compressed air G, with a front rounded end and a downwardly pointed end. When the fuel supply part 350 has the above configuration, at the downstream side of the trailing edge portion 354 of the fuel supply part 350, the formation of a low-flow rate region of the compressed air G containing the fuel F (fuel-containing air) can be suppressed. As a result, it is possible to prevent the ignition of the fuel-containing air or flame stabilization in the compressed air line 300.

[0082] A fuel passage 356 through which the fuel F flows may be disposed inside the fuel supply part 350. Furthermore, the fuel F may be supplied from an external fuel passage 358 to the fuel passage 356 and then injected from the fuel injection hole 360. Furthermore, a fuel adjustment valve 359 for adjusting the supply amount of the fuel F may be disposed at the external fuel passage 358.

[0083] Furthermore, in some embodiments, the concentration of the fuel F in the fuel / air mixture line 200 may be less than or equal to a flammability limit concentration. To adjust the concentration of the fuel F, for example, the supply amount of the fuel F may be adjusted using the fuel adjustment valve 359. When the concentration of the fuel D is less than or equal to the flammability limit concentration, it is possible to suppress the ignition of the fuel / air mixture H in a space other than the combustion chamber 82 inside the combustion liner 80. Furthermore, it is possible to prevent the temperature of the flame from rising locally in the vicinity of the position where the fuel / air mixture H is supplied to the combustion chamber 82 when the fuel / air mixture H is introduced into the combustion chamber 82 and burned. As a result, it is possible to suppress the generation of NO xin the combustion liner 80.

[0084] Embodiments of the present invention have been described above, but the present invention is not limited to them. Various modifications may be made without departing from the scope of the invention. List of reference symbols 1 gas turbine 2 compressors 4 combustion chamber 6 turbines 27 bucket ring 40 Housing interior 54 Fuel nozzle 80 combustion liners 100 interior passage 102 Outlet 200 Fuel / air mixture line 210 Blade ring cooling line 220 bypass line 230 passage switching valve 300 compressed air line 302 cooler 304 Booster Compressor 350 fuel supply part 352 leading edge section 354 trailing edge section F Fuel G Compressed air

Claims

[1] Combustion chamber, comprising: a fuel nozzle (54) for injecting fuel; a combustion liner (80) surrounding a combustion chamber (82) for burning the fuel, the combustion liner (80) having an internal passage (100) with an outlet (102) communicating with the combustion chamber (4); and a fuel / air mixture line (200) for introducing a fuel / air mixture (H) containing the fuel and compressed air into the inner passage (100), wherein the fuel / air mixture line (200) is connected to an inlet of the inner passage (100) of the combustion liner (80), wherein the combustion liner (80) is designed to be cooled by the fuel / air mixture (H) flowing through the inner passage (100); characterized by , that a concentration of the fuel (F) in the fuel / air mixture line (200) is lower than or equal to a flammability limit concentration. [2] Combustion chamber according to claim 1, comprising: a compressed air line (300) through which the compressed air (G) flows; and a fuel supply part (350) for supplying the fuel to the compressed air (G) flowing through the compressed air line (300), the fuel supply part (350) being arranged on the compressed air line (300), wherein the fuel / air mixture line (200) is designed such that the fuel / air mixture (4), which contains the fuel (F) supplied from the fuel supply part (350) and the compressed air (G) flowing through the compressed air line (300), is introduced into the inner passage (100). [3] Combustion chamber according to claim 2, wherein the compressed air line (300) is arranged to extract the compressed air (G) from an intermediate stage of a compressor (2) of a gas turbine (1) having the combustion chamber (4) or a housing interior (40) of the gas turbine (1). [4] Combustion chamber according to claim 2 or 3, wherein the fuel supply part (350) has an airfoil shape comprising: a leading edge portion (352) positioned on an upstream side in a flow direction of the compressed air (G) in the compressed air line (300); and a trailing edge portion (354) positioned on a downstream side of the leading edge portion (352) in the flow direction, the trailing edge portion (354) having a fuel injection hole for injecting the fuel downstream. [5] Combustion chamber according to one of claims 2 to 4, comprising a booster compressor (304) arranged on the compressed air line (300). [6] Combustion chamber according to one of claims 2 to 5, comprising a cooler (302) arranged on the compressed air line (300) for cooling the compressed air (G). [7] Combustion chamber according to one of claims 1 to 6, wherein the fuel / air mixture line (200) comprises a blade ring cooling line (210) which runs inside a blade ring of a gas turbine (1) which has the combustion chamber (4). [8] Combustion chamber according to claim 7, wherein the fuel / air mixture line (200) further comprises a bypass line (220) which bypasses the blade ring cooling line (210), and wherein the combustion chamber (4) further comprises a passage switching valve (230) configured to switch a passage through which the fuel / air mixture (H) flows between the blade ring cooling line (210) and the bypass line (220). [9] A combustion chamber according to any one of claims 1 to 8, wherein the outlet (102) of the inner passage (100) is downstream of a downstream end of the fuel nozzle (54) in an axial direction of a combustion liner (80). [10] Combustion chamber according to one of claims 1 to 9, wherein the inner passage (100) has a plurality of rectilinear passages extending in an axial direction of the combustion liner (80). [11] Gas turbine, comprising: a compressor (2) for generating compressed air (G); the combustion chamber (4) according to one of claims 1 to 10; and a turbine (6) which is arranged to be driven by an exhaust gas from the combustion chamber (4).

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