JP5507504B2 - Gas turbine combustor - Google Patents

Description

  The present invention relates to a gas turbine combustor that supports both liquid and gaseous fuels.

  Along with the liberalization of electric power, in the recent power generation business, in addition to the conventional large-capacity large power plants, small and medium-capacity distributed power sources are becoming popular. Small and medium-capacity power generation facilities often use liquid fuels that are relatively easy to supply, and in addition, there is a need to use various fuels such as natural gas and biofuels to reduce greenhouse gas emissions. is increasing. In response to such a background, there is a demand for a gas turbine power generation facility to which a dual fuel compatible combustor that can handle both liquid fuel and gaseous fuel is applied.

  From the viewpoint of protecting the global environment, environmental regulations such as NOx for exhaust gas from gas turbine combustors are becoming stricter. As one means, there is a pre-evaporation premixed combustion method in which fuel is premixed with air and then burned. is there. As an example, Patent Document 1 discloses that a liquid fuel nozzle is disposed substantially at the center of the mixing chamber, a mixing chamber is provided on the outer periphery of the liquid fuel nozzle, and a plurality of rows of cylindrical air holes are provided on the mixing chamber wall. A gas turbine combustor is disclosed. In the gas turbine combustor having the above-described structure, the NOx emission amount is reduced by performing pre-evaporation premixed combustion in which the liquid fuel injected from the liquid fuel nozzle is evaporated and uniformly mixed with air.

JP 2010-60281 A

  Among liquid fuels, there is an increasing need to use inexpensive fuels such as A heavy oil. In the combustion of an inexpensive fuel containing a high-boiling component such as residual oil, soot and NOx emissions tend to increase. Further, in the combustor having a structure like the above-described dual fuel compatible combustor, when the liquid fuel injected from the liquid fuel nozzle adheres to the wall surface of the mixing chamber, the adhering liquid fuel is pyrolyzed and unburned carbon. Become deposited. If the air holes formed by the unburned carbon in the mixing chamber are blocked to reduce the air flow rate, the atomization characteristics of the liquid fuel are deteriorated, and the NOx emission amount may be increased.

  An object of the present invention is to provide a gas turbine combustor that further reduces NOx emissions while preventing an increase in NOx emissions due to accumulation of unburned carbon in the mixing chamber.

  In order to solve the above problems, the present invention provides a mixing chamber that mixes air and fuel, a liquid fuel nozzle that ejects liquid fuel into the mixing chamber, and an outer peripheral side of the liquid fuel nozzle. A gas turbine combustor having a cylindrical air hole to be ejected, and a gas fuel injection hole for supplying gaseous fuel into the air hole on a wall surface of the air hole, the gas fuel injection hole It has the system which supplies water to water.

  According to the present invention, it is possible to provide a gas turbine combustor that further reduces NOx emission while preventing an increase in NOx emission due to accumulation of unburned carbon in the mixing chamber.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows the structure of the gas turbine combustor in Example 1, and the schematic block diagram which shows schematically the whole structure of a gas turbine power plant. The figure which showed the cross section showing the detailed structure of the pre-mixing combustion burner of Example 1. FIG. The figure which showed the cross section showing the detailed structure of the air hole provided in the premixed combustion burner of Example 1. FIG. Sectional drawing which shows the structure of the gas turbine combustor in Example 2, and the schematic block diagram which shows schematically the whole structure of a gas turbine power plant. The figure which showed the cross section showing the detailed structure of the air hole provided in the premixed combustion burner of Example 2. FIG.

  Embodiments of a gas turbine combustor using the present invention will be described below with reference to the drawings.

  A dual-fuel compatible gas turbine combustor that can use both liquid fuel and gas fuel as an example of an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram of a gas turbine system including a cross-sectional view of a gas turbine combustor according to the present embodiment. The schematic configuration of the gas turbine system of this embodiment will be described with reference to FIG.

  The gas turbine system shown in this embodiment is a part of a gas turbine power plant that uses liquid fuel and gaseous fuel as fuel for the gas turbine. The gas turbine power plant mainly generates a combustion gas 400 by mixing the compressor 1 that compresses air to generate high-pressure combustion air 300, and the combustion air 300 introduced from the compressor 1 and fuel. A gas turbine combustor 3, a turbine 2 that supplies the combustion gas 400 generated by the gas turbine combustor 3, and a generator 4 that is driven by the rotation of the turbine 2 to generate electric power.

  The gas turbine combustor 3 is a dual-fuel compatible gas turbine combustor capable of burning both the liquid fuel 100 and the gaseous fuel 200 as fuel. In the gas turbine combustor 3, the liquid fuel 100 and the gaseous fuel 200 and the combustion air 300 supplied from the compressor 1 are mixed and combusted in the combustion chamber 6 formed in the inner cylinder 7 to generate a high-temperature combustion gas 400. Generate. An outer cylinder 5 that houses the inner cylinder 7, a closing plate 9 that covers an end of the outer cylinder 5, and a high-temperature combustion gas 400 that is generated by connecting to the downstream side of the inner cylinder 7 are supplied to the turbine 2. A pressure vessel sealed with the leading transition piece 8 is formed, and the liquid fuel supply systems 120 and 121 for supplying the liquid fuel 100 and the gaseous fuel 200 and the gaseous fuel supply systems 220 and 221 are connected to the closing plate 9. .

  A diffusion combustion burner 10 having a liquid fuel nozzle 12 and having good combustion stability is installed at the axial center position upstream of the inner cylinder 7 provided in the gas turbine combustor 3. A plurality of premixed combustion burners 11 are arranged around. The premixed combustion burner 11 includes a mixing chamber 11a that premixes fuel and air, and can reduce NOx emission by lean combustion.

  The diffusion combustion burner 10 provided in the gas turbine combustor 3 has a structure in which a conical plate 10b having a hollow conical shape forming a mixing chamber 10a is installed on the inner side, and combustion air 300 is provided on the wall surface of the conical plate 10b. A plurality of air holes 15 for imparting a swirl component are concentrically arranged in two rows. A liquid fuel nozzle 12 that injects the liquid fuel 100 for diffusion combustion is disposed at the axial center position of the diffusion combustion burner 10. On the outer periphery of the liquid fuel nozzle 12, a gas fuel nozzle 14 for ejecting the gas fuel 200 is disposed concentrically at a position close to the upstream side of each air hole 15 formed in the mixing chamber 10 a of the diffusion combustion burner 10. ing. The gaseous fuel 200 injected from each of the gaseous fuel nozzles 14 is structured to be injected into the mixing chamber 10a through the air holes 15 formed in the conical plate 10b while being mixed with the combustion air 300.

  Since the premixed combustion burner 11 provided in the gas turbine combustor 3 will be described in detail later, it will be briefly described here. A liquid fuel nozzle 13 for supplying the liquid fuel 100 is installed at the axial center position on the upstream side of the premixed combustion burner 11. On the downstream side of the liquid fuel nozzle 13, the liquid fuel 100 injected from the liquid fuel nozzle 13 and the combustion air 300 flowing in from a plurality of air holes 16 provided in the wall surface of the premixed combustion burner 11 are mixed. And a mixing chamber 11a for evaporating the liquid fuel 100 is formed. A gas fuel injection hole 17 for injecting the gaseous fuel 200 into the air hole 16 is provided on the wall surface of the air hole 16.

  Next, a fuel supply system in a gas turbine power plant equipped with the gas turbine combustor of the present embodiment will be described.

  In order to supply the liquid fuel 100 to the gas turbine combustor 3, the pressure of the liquid fuel 100 stored in the liquid fuel tank 110 is increased by the pressurizing pump 101, and the pressure is adjusted by the pressure control valve 102. The liquid fuel supply systems 120 and 121 for supplying the liquid fuel 100 with the pressure adjusted to the liquid fuel nozzles 12 and 13 are supplied with flow control valves 103 and 105 for adjusting the flow rate of the liquid fuel 100 and the supply of the liquid fuel 100. Shut-off valves 104 and 106 for shutting off are provided.

  On the other hand, when the gaseous fuel 200 is supplied to the gas turbine combustor 3, the pressure of the gaseous fuel 200 stored in the fuel tank 210 in a liquid state and vaporized by the vaporizer 211 is adjusted by the pressure reducing valve 201. Gas fuel supply systems 220 and 221 having flow control valves 202 and 204 for adjusting the flow rate of fuel supplied to the gas fuel nozzle 14 and the gas fuel nozzle 17 and shutoff valves 203 and 205 for shutting off the supply of the gas fuel 200 are provided. In the arrangement, the gaseous fuel 200 is supplied to the gas turbine combustor 3.

  In addition to the above, the water supply system 223 is connected to the gaseous fuel supply system 221 so that the water 250 can be supplied from the gaseous fuel injection hole 17 provided in the premixed combustion burner 11. The water 250 stored in the water tank 260 is boosted by the pressurizing pump 251, the pressure is adjusted by the pressure control valve 252, the flow rate is adjusted by the flow control valve 253, and the shutoff valve 254 that cuts off the supply of the water 250 is used. The gas fuel supply system 221 is supplied to the premixed combustion burner 11 through the gas fuel injection hole 17 from the downstream side of the shutoff valve 205.

  The gaseous fuel supply system 221 and the water supply system 223 are configured such that when the gaseous fuel 200 or the water 250 is supplied to the gas turbine combustor 3, the gaseous fuel 200 or the water 250 flows back to the supply systems. In order to prevent this, check valves 206 and 256 are installed downstream of the shutoff valves 205 and 254, respectively.

  Next, an operation method of the gas turbine combustor provided in the gas turbine power plant configured as described above will be described. When the operator of the gas turbine power plant selects the liquid fuel 100, the liquid fuel 100 is supplied from the liquid fuel supply system 120 to the diffusion combustion burner 10, and from the liquid fuel supply system 121 to the premixed combustion burner 11. On the other hand, when the operator of the gas turbine power plant selects the gaseous fuel 200, the gaseous fuel 200 is supplied from the gaseous fuel supply system 220 to the diffusion combustion burner 10 and from the gaseous fuel supply system 221 to the premixed combustion burner 11.

  The fuel flow rate is configured to be controlled in accordance with the load of the gas turbine. When the gas turbine is accelerated from start-up and operated under a low load condition, the liquid fuel 100 or the gaseous fuel 200 is used only for the diffusion combustion burner 10. To be operated alone. Furthermore, in the high load condition of the gas turbine in which the fuel flow rate increases, the liquid fuel 100 or the gaseous fuel 200 is supplied to the premixed combustion burner 11 in addition to the diffusion combustion burner 10.

  In the gas turbine combustor 3 provided with the diffusion combustion burner 10 and the premixed combustion burner 11, the ratio of the fuel flow rate between the diffusion combustion and the premixed combustion is controlled so as to achieve both low NOx and stable combustion. The gas turbine combustor 3 is operated. Normally, if the rate of diffusion combustion is reduced, the amount of NOx emissions can be reduced, but the possibility of causing combustion instability increases.

  Next, the structure of the premixed combustion burner provided in the gas turbine combustor will be described in detail with reference to FIG. FIG. 2 is a cross-sectional view of a premixed combustion burner provided in the gas turbine combustor. A liquid fuel nozzle 13 for supplying the liquid fuel 100 is installed at the axial center position on the upstream side of the premixed combustion burner 11, and the liquid injected from the liquid fuel nozzle 13 to the combustion chamber 6 side of the liquid fuel nozzle 13. A mixing chamber 11 a that promotes mixing of the fuel 100 and the combustion air 300 is formed. The upstream side has a hollow conical shape, and the downstream side has a substantially cylindrical shape. On the wall surface of the mixing chamber 11a of the premixed combustion burner 11, cylindrical air holes 16 for introducing the combustion air 300 into the premixed combustion burner 11 are arranged in three rows in the axial direction of the premixed combustion burner 11. A plurality are provided in the circumferential direction. The wall surface provided with these air holes 16 is provided with a gaseous fuel injection hole 17 for ejecting the gaseous fuel 200 or water 250 supplied from the gaseous fuel supply system 221 and the water supply system 223 through the fuel header 18. It has been.

  When the liquid fuel 100 is selected as the fuel, the liquid fuel 100 injected from the liquid fuel nozzle 13 is mixed with the combustion air 300 in the mixing chamber 11a and evaporated. The premixed gas generated by mixing / evaporation becomes a high-temperature combustion gas by combustion in the combustion chamber 6. On the other hand, when the gaseous fuel 200 is selected as the fuel, the gaseous fuel 200 supplied from the gaseous fuel injection hole 17 is mixed with the combustion air 300 and burned due to the turbulence in the air hole 16 or the mixing chamber 11a. It burns in the chamber 6 and becomes high-temperature combustion gas.

  FIG. 2 is a cross-sectional view showing a detailed structure of the premixed combustion burner 11 of the first embodiment. As shown in the AA ′ arrow cross-sectional view of FIG. 2, six air holes 16 are provided in the circumferential direction in this cross section. By providing an air hole 16 at a position that is translated by a length X with respect to a line DD ′ obtained by extending the diameter of the cross-sectional circle of the mixing chamber 11a, a swirling flow 19 is formed in the mixing chamber 11a. Since the shearing force acts on the droplets of the liquid fuel 100 injected from the liquid fuel nozzle 13 by the swirling flow 19 and atomization is promoted, the surface area of the droplets is increased and the liquid fuel 100 is likely to evaporate. Effective in reducing emissions.

  Next, the structure in the vicinity of the air holes of the premixed combustion burner of this embodiment will be described with reference to FIG. FIG. 3 is an enlarged view of a portion B in which the air holes shown in FIG. 2 are surrounded by broken lines. The combustion air 300 is introduced into the mixing chamber 11 a of the premixed combustion burner 11 through the air hole 16. A gas fuel injection hole 17 is provided in the air hole 16, and the gaseous fuel 200 or the water 250 is placed on the same plane with respect to the cross-sectional circle of the air hole 16 as shown in the sectional view taken along the line CC ′. A gas fuel injection hole 17 to be supplied is provided. The jet of gaseous fuel 200 or water 250 supplied from the gaseous fuel injection hole 17 passes through the center of the cross-sectional circle of the air hole 16 and collides with the opposite side wall surface of the gaseous fuel injection hole 17 and is accompanied by the combustion air 300. Flow into the mixing chamber 11a. Combustion air 300 mixed with gaseous fuel 200 or water 250 obtains ignition energy from the combustion heat of the diffusion combustion burner in the combustion chamber and becomes combustion gas by combustion.

  Since the gaseous fuel 200 or water 250 supplied from the gaseous fuel injection hole 17 collides with the wall surface of the air hole 16 opposite to the gaseous fuel injection hole 17, the gaseous fuel 200 or water 250 moves to the outer peripheral side or the mixing chamber side of the premixed combustion burner 11. Direct injection can be prevented. Thereby, it is dispersed in the air holes 16 due to the impact of the collision with the wall surface, and is then accompanied by the combustion air 300 and flows into the mixing chamber. When the gaseous fuel 200 is dispersed and mixed in the combustion air 300, it is possible to prevent the occurrence of a local high-temperature combustion region due to the high fuel concentration and to reduce the NOx emission amount.

  In the gas turbine combustor configured as described above, the effect of supplying the water 250 from the gaseous fuel injection hole 17 when liquid fuel is used as fuel will be described below.

  When the water 250 is supplied from the gaseous fuel injection hole 17, the water 250 collides with the wall surface of the air hole 16, and as a result of the impact, the water 250 becomes droplets and is dispersed and dispersed in the air hole 16. It flows into the mixing chamber. Since the water 250 becomes droplets and scatters in the air holes, the contact area with the combustion air 300 is increased, heat is easily received from the combustion air 300, and evaporation is promoted. Thereby, a local increase in combustion temperature is suppressed due to a decrease in temperature of combustion air 300 and a decrease in combustion speed due to the addition of water 250, and NOx emission can be reduced.

  On the other hand, when the combustion air 300 is caused to flow into the mixing chamber 11 a from the air hole 16, a wake 50 is generated at the outlet of the air hole 16. If some of the liquid fuel droplets injected from the liquid fuel nozzle are caught in the wake 50, the liquid fuel droplets may adhere to the wall surface of the mixing chamber 11a or the evaporation chamber downstream thereof. If the liquid fuel 100 stays for a long time with adhering to the wall surface, it becomes unburned carbon by thermal decomposition and accumulates on the mixing chamber 11a and the evaporation wall surface. In particular, when a component having a boiling point higher than the temperature of the combustion air 300 (high boiling point component) is present in the liquid fuel 100, it is difficult to evaporate the high boiling point component. Increases significantly.

  On the other hand, in the structure of the premixed combustion burner 11 of this embodiment, the temperature of the structure of the premixed combustion burner 11 is increased by a part of the water 250 ejected from the gaseous fuel injection hole 17 flowing on the wall surface of the air hole 16. It is decreasing. By doing so, the thermal decomposition reaction rate of the liquid fuel can be reduced. Thereby, even if a high-boiling component adheres to the wall surface of the mixing chamber 11a, it becomes easy to be transported to the combustion chamber downstream of the mixing chamber 11a by the combustion air 300, and generation of unburned carbon can be suppressed.

  The gas turbine combustor of the present embodiment described above is disposed on the outer peripheral side of the liquid fuel nozzle 13, the mixing chamber 11 a that mixes air and fuel, the liquid fuel nozzle 13 that ejects liquid fuel into the mixing chamber 11 a. A gas turbine combustor having a cylindrical air hole 16 for jetting air, and a gas fuel injection hole 17 for supplying gaseous fuel into the air hole 16 on a wall surface of the air hole 16, A system 223 for supplying water to the gaseous fuel injection hole 17 is provided. Then, when supplying the liquid fuel from the liquid fuel nozzle 13, the water 250 is supplied to the gaseous fuel injection hole 17.

  In the gas turbine combustor configured as described above, water is injected from the gas fuel injection holes during the oil-only firing operation, thereby depositing unburned carbon generated by the liquid fuel adhering to the wall surface of the premixed combustion burner. Can be suppressed. As a result, changes in the atomization characteristics of the liquid fuel injected from the liquid fuel nozzle due to a decrease in the air flow rate into the mixing chamber and an increase in the flow rate deviation of the air flowing into the mixing chamber from individual air holes can be suppressed. The generation of the high temperature region of the flame due to the is suppressed, and the increase in the NOx emission amount can be prevented. Moreover, since the mixing degree of combustion air and water can be increased, it is possible to provide a gas turbine combustor that can suppress an increase in the temperature of the flame and can reduce NOx emissions.

  A second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a configuration diagram of a gas turbine system including a cross-sectional view of the gas turbine combustor of the present embodiment. The configuration of the gas turbine combustor of this embodiment shown in FIG. 4 and the schematic configuration of the gas turbine system are basically the same as those shown in FIG. Hereinafter, the difference between the two will be described.

  The system of the present embodiment shown in FIG. 4 is provided with a water supply system 224 branched from the water supply system 223, connected to the gaseous fuel supply system 220, and can supply water 250 from the gaseous fuel nozzle 14 of the diffusion combustion burner 10. I am doing so. The water supply system 224 is branched from the water supply system 223 in a state where the water 250 stored in the water tank 260 is pressurized by the pressure pump 251 and the pressure is adjusted by the pressure control valve 252. The branched water supply system 224 is provided with a flow rate control valve 257 for adjusting the flow rate of the water 250, a shutoff valve 258 for shutting off the supply of the water 250, and a check valve 259 for preventing backflow. Yes. The water supply system 224 joins to the downstream side of the check valve 207 provided in the gaseous fuel supply system 220 and is supplied to the diffusion combustion burner 10 through the gaseous fuel nozzle 14.

  The water supply systems 223 and 224 are provided with heat exchangers 270 and 275, respectively, to adjust the temperature of the water 250 as the pressure of the combustion air 300 changes. The pressure of the combustion air 300 is preferably measured directly at the fuel header 18 of the diffusion combustion burner 10 and the premixed combustion burner 11, but here the pressure is set downstream of the heat exchangers 270 and 275 of the water supply systems 223 and 224. A total of 272 and 277 are installed and measured. Further, the temperature of the water 250 in the water supply systems 223 and 224 is also measured by installing thermometers 273 and 278 on the downstream side of the heat exchangers 270 and 275.

  The controller 271 controls the operation of the heat exchanger 270 from the measurement results of the pressure gauge 272 and the thermometer 273 to adjust the temperature of the water 250, thereby supplying the premixed combustion burner 11 with water 250 having a temperature lower than the boiling point. Similarly, the operation of the heat exchanger 275 is controlled by the regulator 276 from the measurement results of the pressure gauge 277 and the thermometer 278, and the temperature of the water 250 is adjusted, so that the water 250 having a boiling point is supplied to the diffusion combustion burner 10. . That is, the temperature of the water 250 supplied from the gaseous fuel injection hole 17 is set to be lower than the boiling point based on the pressure of the combustion air. If it does so, the production | generation of the carbon of the unburned part by thermal decomposition of liquid fuel can be suppressed.

  Since the water 250 is individually supplied to the diffusion combustion burner 10 and the premixed combustion burner 11, the water 250 can be supplied from the gaseous fuel nozzle 14 to the mixing chamber 10 a even in the oil combustion of the diffusion combustion burner 10. The temperature of the flame formed by the diffusion combustion burner with a large amount of NOx emission can be reduced, and the amount of NOx emission is reduced.

  Next, the structure in the vicinity of the air holes of the premixed combustion burner of the combustor according to this embodiment will be described with reference to FIG. The premixed combustion burner 11 is substantially the same as that shown in FIG. However, the structure of the premixed combustion burner 11 in the vicinity of the air holes is different from that of the first embodiment. That is, it is a structure different from FIG. 3 in which the portion B in which the air holes shown in FIG. 2 are surrounded by broken lines is enlarged. This point will be described with reference to FIG.

  FIG. 5 is an enlarged view of a portion corresponding to part B in which the air holes shown in FIG. 2 are surrounded by broken lines. The combustion air 300 is introduced into the mixing chamber 11 a of the premixed combustion burner 11 through the air hole 16. The air hole 16 has a cylindrical shape, and a gas fuel injection hole 17 is provided on the wall surface of the cylindrical air hole 16. That is, as shown in the sectional view taken along the line CC ′, the gaseous fuel injection hole 17 for supplying the gaseous fuel 200 or the water 250 from the tangential direction with respect to the sectional circle of the air hole 16 is provided. Then, the jet of the gaseous fuel 200 or the water 250 supplied from the gaseous fuel injection hole 17 flows along the wall surface of the air hole 16, and flows along with the combustion air 300 into the mixing chamber 11a. Combustion air 300 mixed with gaseous fuel 200 or water 250 obtains ignition energy from the combustion heat of the diffusion combustion burner in the combustion chamber and becomes combustion gas by combustion.

  It is desirable to arrange the central axis of the gaseous fuel injection hole 17 in the vicinity of the outlet of the air hole. Specifically, it is preferable to arrange at a position closer to the outlet (inside of the premixed combustion burner 11) than the inlet of the air hole 16 (outside of the premixed combustion burner 11). In particular, in this embodiment, when the plane perpendicular to the cylinder formed by the air holes 16 is moved from the outside of the premixed combustion burner 11 to the mixing chamber 11a side, the plane perpendicular to the cylinder first does not come into contact. The center of the gaseous fuel injection hole 17 was arranged on a certain plane. By arranging in this way, the gaseous fuel 200 or water 250 supplied from the gaseous fuel injection hole 17 flows along the wall surface of the air hole 16, and a part of the gaseous fuel 200 or water 250 scatters into the mixing chamber 11a from where the restriction by the wall is removed. It becomes the flow 51. This is preferable because a turning force can be applied to the fluid without losing the momentum of the fluid such as the gaseous fuel 200 or the water 250 more than necessary.

  In the case of the gaseous fuel 200, it flows along the wall surface of the air hole 16 and spreads in a film shape on the inner wall. Then, since the gaseous fuel 200 is dispersed and mixed in the combustion air 300, it is possible to prevent the occurrence of a local high-temperature combustion region due to the high fuel concentration, and to reduce the NOx emission amount.

  Next, in the gas turbine combustor having the above-described configuration, the effect of supplying the water 250 from the gaseous fuel injection hole 17 when liquid fuel is used as fuel will be described below.

  When the water 250 is supplied from the gaseous fuel injection hole 17, the water 250 spreads in the form of a liquid film on the wall surface of the air hole 16, so that the contact area with the wall surface of the air hole 16 increases, Evaporation is promoted. Thereby, a local increase in combustion temperature is suppressed due to a decrease in temperature of combustion air 300 and a decrease in combustion speed due to the addition of water 250, and NOx emission can be reduced. The total amount of water 250 supplied from the gaseous fuel injection hole 17 is mixed with the premixed gas formed by the premixed combustion burner 11, and the total amount of water 250 contributes to the reduction of NOx emission. Even if the supply amount of water 250 is small, it is effective in reducing the NOx emission amount.

  Here, in the structure in which the combustion air 300 flows into the mixing chamber 11 a from the air hole 16, a wake 50 is generated at the outlet of the air hole 16. Some of the liquid fuel droplets injected from the liquid fuel nozzle are entrained in the wake 50, and the unburned carbon easily accumulates on the wall surface. On the other hand, in the structure of the premixed combustion burner 11 of the present embodiment, the water 250 flows through the wall surface of the air hole 16 to reduce the wall surface temperature of the air hole 16 and the wall surface temperature of the mixing chamber 11a. The flow 51 is pressed against the wall surface by the wake 50 and approaches the wall surface of the mixing chamber 11a to cool the wall surface of the mixing chamber 11a, thereby reducing the thermal decomposition reaction rate of the liquid fuel. As a result, even if a high-boiling component adheres to the wall surface of the mixing chamber 11a, it becomes easy to be transported to the combustion chamber downstream of the mixing chamber 11a by the combustion air 300, and generation of unburned carbon by pyrolysis is generated. Can be suppressed. Further, the flow 51 in which a part of the water 250 scatters from the air holes 16 to the mixing chamber 11a prevents the liquid fuel from adhering to the wall surface of the mixing chamber 11a, and flows into the combustion chamber together with the water 250 or water vapor. Generation of fuel carbon can be suppressed.

  Further, the gas turbine according to the present embodiment includes heat exchangers 270 and 275 which are heating means for heating the water 250 supplied to the gaseous fuel injection hole 17. Therefore, the water 250 is heated before being supplied to the premixed combustion burner 11, and evaporation is started immediately after the water 250 is ejected from the gaseous fuel injection hole 17, the degree of mixing with the combustion air 300 is increased, and a local flame is produced. The NOx emission can be reduced by preventing the temperature from rising. Further, since the water 250 is heated by the heat exchanger 270, the water 250 is easily evaporated in the vicinity of the air hole 16, and the temperature of the structure is lowered by the heat of vaporization. Generation and accumulation of unburned carbon on the wall surface of 11a can be suppressed.

  Further, since the premixed combustion burner 11 is heated by the combustion air 300, the heat applied to the welded portion or the like due to a rapid temperature change as compared with the case where normal temperature water is supplied by supplying heated water 250. Stress can be reduced and cracking of the structure can be prevented.

  In the gas turbine combustor and the gas turbine system configured as described above, the vicinity of the air hole of the premixed combustion burner can be cooled by injecting water from the gas fuel injection hole during the oil-only firing operation, and the wall surface of the premixed combustion burner It is possible to suppress accumulation of unburned carbon generated by the liquid fuel adhering to the surface. As a result, changes in the atomization characteristics of the liquid fuel injected from the liquid fuel nozzle due to a decrease in the air flow rate into the mixing chamber and an increase in the flow rate deviation of the air flowing into the mixing chamber from individual air holes can be suppressed. The generation of the high temperature region of the flame due to the is suppressed, and the increase in the NOx emission amount can be prevented. Moreover, since the mixing degree of combustion air and water can be increased, it is possible to provide a gas turbine combustor that can suppress an increase in the temperature of the flame and can reduce NOx emissions.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Turbine 3 Gas turbine combustor 4 Generator 5 Outer cylinder 6 Combustion chamber 7 Inner cylinder 8 Transition piece 9 Closure plate 10 Diffusion combustion burner 10a, 11a Mixing chamber 10b Conical plate 11 Premixed combustion burner 12, 13 Liquid fuel Nozzle 14 Gaseous fuel nozzle 15, 16 Air hole 17 Gaseous fuel injection hole 18 Fuel header 50 Wake 51 Flow 100 Liquid fuel 101, 251 Pressure pump 102, 252 Pressure control valve 103, 105, 202, 204, 253 Flow control valve 104, 106, 203, 205, 254 Shut-off valve 110 Liquid fuel tank 120, 121 Liquid fuel supply system 200 Gas fuel 220, 221, 221 Gas fuel supply system 206, 256 Check valve 210 Fuel tank 223 Water supply system 250 Water 260 Water tank 270 heat exchanger 271 regulator 272 pressure Total 273 Thermometer 300 Combustion air 400 Combustion gas

Claims (7)

A mixing chamber for mixing air and fuel;
A liquid fuel nozzle for ejecting liquid fuel into the mixing chamber;
A cylindrical air hole that is disposed on the outer peripheral side of the liquid fuel nozzle and ejects air;
A gas turbine combustor comprising a gas fuel injection hole for supplying gaseous fuel into the air hole on a wall surface of the air hole,
A gas turbine combustor comprising a system for supplying water to the gaseous fuel injection hole. A gas turbine combustor according to claim 1,
Is the gas fuel injection holes, the gas turbine combustor, wherein a fluid supplied from the gas fuel injection holes are provided to flow along the wall surface of the air pores. A gas turbine combustor according to claim 1 or 2,
The air hole is cylindrical,
The gas turbine combustor, wherein the gas fuel injection hole is provided so that fluid is supplied from a tangential direction with respect to a cross-sectional circle of the cylindrical air hole. 4. The gas turbine combustor according to claim 1, further comprising a heating unit configured to heat water supplied to the gaseous fuel injection hole. 5. A gas turbine combustor according to any one of claims 1 to 4,
A gas turbine combustor having a structure in which the gaseous fuel injection hole is disposed at a position closer to the outlet than the inlet of the air hole. A mixing chamber for mixing air and fuel;
A liquid fuel nozzle for ejecting liquid fuel into the mixing chamber;
A cylindrical air hole that is disposed on the outer peripheral side of the liquid fuel nozzle and ejects air;
A gas turbine combustor operating method comprising a gas fuel injection hole for supplying gaseous fuel into the air hole on a wall surface of the air hole,
When supplying liquid fuel from the liquid fuel nozzle,
A method for operating a gas turbine combustor, wherein water is supplied to the gaseous fuel injection hole. A method for operating a gas turbine combustor according to claim 6,
A method for operating a gas turbine combustor, wherein the temperature of water supplied from the gaseous fuel injection hole is determined based on the pressure of combustion air.

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