JP4719704B2 - Gas turbine combustor - Google Patents

Description

  The present invention relates to a gas turbine combustor that uses, as a gas turbine fuel, low-quality oil that contains more residual carbon than liquid fuel such as light oil and A heavy oil, and in particular, when a low-quality oil fuel containing residual carbon is burned. The present invention relates to a gas turbine combustor including a fuel spray nozzle device that reduces generated dust.

  In recent years, diversification of fuels has been studied in gas turbines, and the use of by-product oil (low quality oil) generated in petroleum refineries, chemical plants, and the like as fuel for gas turbines has been studied.

  This low-quality oil is less expensive than light oil and heavy fuel oil A, which are mainly used as fuel for gas turbines. If this low-quality oil can be used as fuel for gas turbines, there is an advantage that the running cost of fuel costs can be greatly reduced. is there.

  However, since this low-quality oil contains more residual carbon than light oil and heavy oil A, soot dust derived from residual carbon that is abundant in low-quality oil such as cenosulfa is generated during combustion, resulting in a higher dust concentration. As a result, there is a problem that the environmental regulation value of dust is not satisfied, and this problem is a major cause that is a problem in using low-quality oil as fuel for gas turbines.

  Japanese Patent Application Laid-Open No. 2004-3730 discloses a technology of a gas turbine combustor for diffusion combustion having a fuel spray nozzle that uses a general liquid fuel but enables reduction of NOx emissions. Has been.

  In the fuel spray nozzle of the gas turbine combustor described in Japanese Patent Application Laid-Open No. 2004-3730, an outer peripheral fuel injection hole and an inner peripheral fuel injection hole for injecting fuel into the combustion chamber face the combustion chamber. In addition, a flow path resistance means is provided in the fuel flow path of the inner peripheral fuel injection hole.

  In the fuel spray nozzle having the above-described configuration, it is possible to eject the fuel whose flow velocity is slower than the fuel ejected from the outer peripheral fuel injection hole into the combustion chamber from the inner peripheral fuel injection hole by installing the flow path resistance means. Therefore, the fuel jet can be supplied from the inner peripheral fuel injection hole to cause a combustion reaction to the low oxygen concentration region having a low oxygen concentration formed in the combustion chamber near the fuel spray nozzle.

  As a result, the flow rate of fuel burned in the low oxygen concentration region formed in the combustor of the total fuel injection amount can be increased, so that the high temperature combustion gas region is limited to a narrow range and the amount of NOx generated is reduced. It is to reduce.

JP 2004-3730 A

  By the way, as a fuel of a gas turbine combustor for diffusion combustion provided with a fuel spray nozzle as described in Japanese Patent Application Laid-Open No. 2004-3730, a low quality oil containing more residual carbon than liquid fuel such as light oil or heavy fuel oil A. Is used, a part of the residual carbon is formed as a shell on the surface of the atomized droplet, so that it takes time to evaporate the droplet as compared with a fuel such as light oil or A heavy oil.

  In addition, after the fuel inside the droplets evaporates, a shell formed on the droplet surface called cenosphere remains.

  Although Senospha disappears in the process of combustion, low quality oil takes longer to evaporate than fuel of light oil and heavy oil A, and reaction time is also required for the disappearance of Senospha, so dust generated when burning low quality oil The concentration becomes higher, which causes an increase in dust when burning low quality oil containing residual carbon.

  Low quality oil is less expensive than light oil or heavy fuel oil A, which is mainly used as gas turbine fuel. If this low quality oil can be used as gas turbine fuel, there is an advantage that the running cost of fuel cost can be greatly reduced.

  However, since this low-quality oil contains more residual carbon than light oil and heavy fuel oil A, as described above, when low-quality oil is burned, residual carbon-derived soot that is contained in low-quality oil such as cenosulfa in large quantities. As a result, there is a problem that the dust concentration becomes high, and as a result, the environmental regulation value of dust is not satisfied, and this problem is a major cause that is a problem in using low quality oil as fuel for gas turbines It is.

  It is an object of the present invention to ensure combustion stability in the operating load range of a gas turbine when low quality oil is used as a fuel for a gas turbine combustor, and to reduce the concentration of dust generated during combustion of low quality oil. Is to provide a vessel.

  The gas turbine combustor according to the present invention is a gas turbine combustor that uses a low-quality oil fuel containing residual carbon as a gas turbine fuel, and is provided with a fuel spray nozzle device that injects the low-quality oil fuel into the combustion chamber. Is provided with a swirler on the outer peripheral side thereof for swirling a part of the combustion air supplied to the gas turbine combustor and flowing into the combustion chamber, and at the center in the radial direction, the combustion air for ejecting spray air into the combustion chamber The fuel spray nozzle device is provided with a hole, and a fuel nozzle that ejects low-quality oil fuel, and a spray that is installed on the outer peripheral side of the fuel nozzle and ejects atomized air that refines the low-quality oil fuel injected from the fuel nozzle A plurality of spray nozzles provided with an air supply nozzle are arranged on the outer peripheral side of the combustion air hole.

  According to the present invention, when low quality oil is used as a fuel for a gas turbine combustor, combustion stability is ensured in the operating load range of the gas turbine, and concentration of dust generated during combustion of low quality oil is reduced. Can be realized.

  Next, a gas turbine combustor which is an embodiment of the present invention will be described below with reference to the drawings.

  A gas turbine combustor according to an embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 1 shows a schematic configuration of a gas turbine power plant 1 of a simple cycle and a partial enlargement of a gas turbine combustor provided with a fuel spray nozzle device 60 for burning low quality oil as a gas turbine combustor 3 of the gas turbine power plant 1. Each figure is shown.

  In FIG. 1, a gas turbine power plant 1 includes an air compressor 2 that compresses and pressurizes air, and a gas that generates combustion gas by burning compressed air pressurized by the air compressor 2 and low-quality fuel oil. A turbine combustor 3, a turbine 4 driven by the combustion gas generated by the gas turbine combustor 3, and a generator 6 that is rotated by the driven turbine 4 and generates electric power are provided.

  The gas turbine power plant 1 of the simple cycle is also provided with a starting motor 8 for driving a gas turbine that drives the air compressor 2 at the time of starting.

  A fuel spray nozzle device 60 is installed at the head of the gas turbine combustor 3 of the gas turbine power plant 1 described above.

  The nozzle side of the fuel spray nozzle device 60 faces the combustion chamber 3a formed inside the gas turbine combustor 3, and the opposite side of the nozzle of the fuel spray nozzle device 60 gasses the low quality oil fuel 200a serving as fuel. A low quality oil fuel system 200 is disposed to be supplied to a nozzle body 61 constituting the fuel spray nozzle device 60 of the turbine combustor 3.

  The nozzle body 61 of the fuel spray nozzle device 60 has an air compressor 2 as spray air 103 a for atomizing the low quality oil fuel 200 a supplied from the fuel spray nozzle device 60 to the combustion chamber 3 a of the gas turbine combustor 3. A part of the pressurized compressed air is further pressurized by the pressurizing compressor 14, and a spray air system 103 that guides the pressurized compressed air as the spray air 103 a to the fuel spray nozzle device 60 is disposed.

  The spray air system 103 is provided with a spray air pressure control valve 15 for adjusting the pressure of the spray air 103 a to be sprayed on the downstream side of the booster compressor 14.

  The combustion air 102 a supplied to the gas turbine combustor 3 is supplied with compressed air compressed by the air compressor 2 through the combustion air system 102, and has a cylindrical shape that partitions the combustion chamber 3 a of the gas turbine combustor 3. The air flows between the combustor liner 11 and the cylindrical outer cylinder 10 provided outside the combustor liner 11 and flows into the combustion chamber 3a.

  Further, in the fuel spray nozzle device 60, the combustion air 2a flowing down through the air flow path between the combustor liner 11 and the outer cylinder 10 is supplied with the spray vapor 104a necessary for NOx reduction in the combustion chamber of the gas turbine combustor 3. A steam spraying system 104 for spraying on 3a is arranged.

  The steam spraying system 104 includes a shutoff valve 301 that shuts off the sprayed steam 104a, and a steam flow rate control valve 302 that is located downstream of the shutoff valve 301 and that regulates an optimum flow rate of the sprayed steam 104a sprayed on the combustion chamber 3a. Are installed.

  When the low-quality oil fuel 200a has a high viscosity and it is necessary to heat the low-quality oil fuel system 200 of the low-quality oil fuel 200a in order to obtain a low viscosity necessary for atomizing the low-quality oil 200a, a gas turbine The gas turbine is started by supplying another fuel such as light oil to the fuel spray nozzle device 60 of the gas turbine combustor 3 for starting the gas turbine, and the fuel is changed from the light oil to the low quality oil fuel 200a under the low load condition after the starting. Although it is conceivable to perform the switching operation of the fuel to be switched, in this embodiment, it is assumed that the gas turbine can be started by the single fuel of the low-quality oil fuel 200a.

  Next, the operation method of the gas turbine power plant 1 provided with the above gas turbine combustor 3 will be described.

  In FIG. 1, when starting the gas turbine power plant 1, the air compressor 2 and the turbine 4 are integrally rotated by external power such as a starter motor 8, and the combustion air is compressed by the air compressor 2. Combustion chamber of the gas turbine combustor 3 uses the discharge air 102 a supplied to the gas turbine combustor 3 through the system 102 and the low quality oil 200 a supplied to the fuel spray nozzle device 60 of the gas turbine combustor 3 through the low quality oil fuel system 200. The low quality oil fuel 200a is ignited and burned by being ejected to 3a.

  The combustion gas 110a generated by burning the low quality oil fuel 200a inside the combustion chamber 3a of the gas turbine combustor 3 is supplied to the turbine 4 through the combustion gas passage 110, and the turbine 4 is supplied by the supplied combustion gas 110a. Drive.

  As the supply flow rate of the low quality oil fuel 200a burned in the combustion chamber 3a of the gas turbine combustor 3 increases, the flow rate of the combustion gas 110a generated by the combustion of the low quality oil fuel 200a increases in the combustion chamber 3a. The turbine 4 driven by 110a is accelerated.

  When the turbine 4 is increased to a desired rotational speed, the starter motor 8 is disengaged, and the gas turbine power plant 1 enters a self-sustained operation and reaches a rated rotational speed with no load.

  After the gas turbine power plant 1 reaches the no-load rated rotational speed, the generator 6 is inserted and power generation is started. The gas turbine is further increased by increasing the flow rate of the low quality oil fuel 200a supplied to the gas turbine combustor 3. The flow rate of the combustion gas 110a generated by the combustor 3 is also increased, and power generation is performed to increase the load of the generator 6 driven by the turbine 4 to a desired load.

  In addition, after loading the generator 6, the injected steam 104a led to the combustion chamber 3a of the gas turbine combustor 3 through the steam injection system 104 to reduce the concentration of NOx and the like contained in the combustion gas 110a. Is configured to inject.

  The fuel spray nozzle device 60 provided at the head of the gas turbine combustor 3 is provided with a swirler 52 on the outer peripheral side of the tip of the fuel spray nozzle device 60, and is supplied to the gas turbine combustor 3 from the air compressor 2. A part of the combustion air 102a is guided by pressure balance, and swirl is applied to the combustion air 102a supplied to the combustion chamber 3a by the swirler 52 provided annularly on the outer peripheral side of the fuel spray nozzle device 60. Thus, the fuel is supplied into the combustion chamber 3a and a circulation flow is generated to hold the flame 81 formed by the combustion of the low quality oil fuel 200a inside the combustion chamber 3a.

  The injected steam 104 a supplied to the gas turbine combustor 3 passes through a shutoff valve 301 installed in the steam injection system 104, is adjusted to an appropriate flow rate by the steam flow rate adjusting valve 302, and then burns air from the air compressor 2. The injected steam 104a is injected and mixed into the combustion air 102a flowing down the air flow path between the outer cylinder 10 of the gas turbine combustor 3 and the combustion chamber liner 11 through the system 102.

  The combustion air 102a into which the injected steam 104a has been injected flows into the combustion chamber 3a of the gas turbine combustor 3 through the swirler 52 provided in the fuel spray nozzle device 60.

  Since the combustion air 102a mixed with the jet steam 104a has a reduced oxygen concentration in the air, the low quality oil fuel 200a is combusted by burning the low quality oil fuel 200a with the low oxygen concentration air in the combustion chamber 3a of the gas turbine combustor 3. It is possible to reduce the temperature of the flame 81 formed in the chamber 3a and suppress the generated NOx concentration.

  On the other hand, the air necessary for atomization of the low-quality oil fuel 200 a is pressurized to a predetermined pressure by the booster compressor 14 by using the booster compressor 14 and the pressurized air is supplied to the gas turbine combustor 3 through the spray air system 103. The fuel spray nozzle device 60 is supplied as spray air 103a.

  The spray air 103a has a constant ratio between the pressure of the low-quality oil fuel 200a flowing through the fuel spray nozzle device 60 of the gas turbine combustor 3 and the supply pressure of the spray air 103a by the pressure control valve 15 installed in the spray air system 103. It is controlled to become.

  Next, a partially enlarged cross-sectional view of the fuel spray nozzle device 60 installed in the gas turbine combustor 5 of the present embodiment shown in FIG. 1 is shown in FIG. 2, and a front view of the fuel spray nozzle device 60 shown in FIG. As shown in FIG.

  In the fuel spray nozzle device 60 of the gas turbine combustor 3 shown in FIGS. 1 to 3, the low quality oil fuel 200a supplied to the fuel spray nozzle device 60 through the external low quality oil fuel system 200 is the fuel spray nozzle device. A distributed fuel flow that is led into the fuel spray nozzle device 60 through a fuel flow path 201 formed inside a nozzle body 61 that constitutes 60 and causes the low quality oil fuel 200a distributed from the fuel flow path 201 to flow down due to pressure balance. A plurality of, for example, four, spray nozzles 72 having passages 202 formed therein are ejected into the combustion chamber 3a.

  Further, the spray air 103 a supplied to the fuel spray nozzle device 60 via the external spray air system 103 passes through the spray air flow path 203 formed inside the nozzle body 61 constituting the fuel spray nozzle device 60. Combustion chamber 3a is formed from the four spray nozzles 72, which are formed in the distribution spray air flow path 204, which is led into the apparatus 60 and flows down the spray air 103a distributed from the spray air flow path 203 by pressure balance. Is erupted.

  Four spray nozzles 72 provided inside the fuel spray nozzle device 60 are provided with fuel nozzles 70 for injecting the low quality oil fuel 200a on the axial center side, and the low quality oil fuel 200a is provided on the outer peripheral side of the fuel nozzle 70. The atomizing air supply nozzle 71 which injects the atomizing air 103a which refines the air is installed.

  A distribution fuel passage 202 is formed inside the fuel nozzle 70, and the low quality oil fuel 200a distributed from the fuel passage 201 formed in the fuel spray nozzle device 60 is caused to flow down from the spray nozzle 72 to the combustion chamber 3a. It is designed to erupt.

  Further, a distribution spray air flow path 204 is formed inside the spray air supply nozzle 71, and the spray air 103 a distributed from the spray air flow path 203 formed in the fuel spray nozzle device 60 is caused to flow down to form the spray nozzle. 72 is ejected into the combustion chamber 3a.

  In this spray nozzle 72 having both the fuel nozzle 70 and the spray air supply nozzle 71, the spray air 103 a injected from the spray air supply nozzle 71 with respect to the low quality oil fuel 200 a injected from the fuel nozzle 70. The low-quality oil fuel 200a is atomized by generating a shearing force by the spray air 103a with respect to the jetted low-quality oil fuel 200a by the relative speed, and the low-quality oil fuel 200a refined from the spray nozzle 72 is supplied to the gas turbine combustor 3. It sprays on the inside of the combustion chamber 3a.

  The refined low quality oil fuel 200a sprayed from the spray nozzle 72 of the fuel spray nozzle device 60 to the inside of the combustion chamber 3a is evaporated and vaporized inside the combustion chamber 3a to burn and form a flame 81. 81 is formed in the combustion chamber 3a according to the number of spray nozzles 72 provided in plurality.

  Further, in the fuel spray nozzle device 60, a part of the spray air 103a is ejected along the axial center in the combustion chamber 3a from the combustion air hole 65 provided in the central portion on the inner peripheral side of the four spray nozzles 72 installed. As a result, the sprayed air 103a is supplied in the vicinity of the sprayed low-quality oil fuel 200a, and the generation of soot dust in the vicinity of the spray nozzle 72 is suppressed.

  That is, the spray air 103 a supplied to the fuel spray nozzle device 60 via the external spray air system 103 passes through the spray air flow path 203 formed inside the nozzle body 61 constituting the fuel spray nozzle device 60. Guided into the device 60.

  In the fuel spray nozzle device 60, a distributed spray air flow path 205 is formed to flow down the spray air 103a distributed from the spray air flow path 203, and the spray distributed from the spray air flow path 203 due to pressure balance. Air 103 a is caused to flow down through the distribution spray air flow path 205.

  The distribution spray air flow path 205 is formed so as to communicate with the combustion air hole 65 provided in the central portion in the radial direction of the fuel spray nozzle device 60 on the inner peripheral side of the spray nozzle 72. Part of the atomized air 103a is ejected along the axial center in the combustion chamber 3a.

  By adopting the gas turbine combustor 3 provided with the fuel spray nozzle device 60 described above, generation of soot is suppressed when the low quality oil fuel 200a supplied in the combustion chamber 3a burns, or the soot concentration is greatly increased. The reason why it can be reduced will be described below.

  In the combustion chamber 3a of the gas turbine combustor 3, the fuel concentration of the low quality oil fuel 200a sprayed from the fuel spray nozzle device 60 is larger in the region near the axial center of the combustion chamber 3a than in the radially outward side. Since the fuel concentration is high, the oxygen concentration in the region near the axis is conversely lower than that on the radially outward side.

  When the low quality oil fuel 200a sprayed in the combustion chamber 3a is burned in this state, a large amount of soot is generated from the region in the vicinity of the shaft center in the combustion chamber 3a having a high fuel concentration and a low oxygen concentration. .

  Therefore, in order to suppress the generation of soot during combustion of the low-quality oil fuel 200a, the spray air 103a is supplied from the combustion air hole 65 provided in the center portion in the radial direction of the tip of the fuel spray nozzle device 60 to the axial center in the combustion chamber 3a. By supplying to the nearby region, the situation in the region near the axis is improved to a state where the oxygen concentration is increased by lowering the fuel concentration.

  As a result, even when the low quality oil fuel 200a sprayed in the combustion chamber 3a is burned, the generation of soot can be suppressed or greatly reduced.

  The flow rate of the low-quality oil fuel 200a supplied to the gas turbine combustor 3 having the above-described structure is increased to increase the combustion gas 110a generated in the gas turbine combustor 3, and the turbine 4 is driven by the combustion gas 110a. Then, the load of the generator 6 is increased, and finally the gas turbine power plant 1 reaches the rated load.

  As the load on the generator 6 increases, the pressure in the combustion chamber 3a of the gas turbine combustor 3 also increases, so that the fuel spray of the gas turbine combustor 3 changes according to changes in the state of the gas turbine combustor 3 such as pressure. Operation control is performed so that the flow rate of the spray air 103a supplied to the nozzle device 60, that is, the supply pressure of the spray air 103a is also a necessary condition corresponding to the change in the state.

  In the fuel spray nozzle device 60 provided in the gas turbine combustor 3 of the present embodiment, a plurality of spray nozzles 72 are installed in the fuel spray nozzle device 60, and these spray nozzles 72 receive the low quality oil fuel 200a on the axial center side. Since the fuel nozzle 70 for injection and the spray air supply nozzle 71 for spraying the spray air 103a for refining the low-quality oil fuel 200a on the outer peripheral side of the fuel nozzle 70 are provided, the combustion chamber 3a has an internal structure. A plurality of flames 81 are formed by the low quality oil fuel 200a injected from the plurality of spray nozzles 72, respectively.

  A swirler 71b is installed in the middle of the flow path through which the spray air 103a of the spray air supply nozzle 71 flows down, so that the spray air 103a flowing down can be swirled.

  By configuring the fuel spray nozzle device 60 provided in the gas turbine combustor 3 as described above, the adjacent flame formed by burning the low quality oil fuel 200a injected from the fuel spray nozzle device 60 into the combustion chamber 3a. In the region in the combustion chamber 3a in contact with 81, the temperature decrease is reduced, so that the evaporation of the low-quality oil fuel 200a injected into the combustion chamber 3a is further promoted, and the low-quality oil fuel in the combustion chamber 3a. It becomes possible to form the flame 81 formed by burning 200a more satisfactorily.

  Further, the fuel spray nozzle device 60 is provided with a plurality of spray nozzles 72 each having a fuel nozzle 70 and a spray air supply nozzle 71, four in this embodiment, so that low quality oil per spray nozzle 72 is provided. Since the fuel flow rate of the fuel 200a can be reduced, the length of the flame 81 formed in the combustion chamber 3a can be shortened.

  As a result, the fuel spray is accompanied by the shortening of the length of the flame 81 where the low quality oil fuel 200a sprayed from the fuel spray nozzle device 60 into the combustion chamber 3a reaches the axial center direction of the combustion chamber 3a. Since it shifts closer to the nozzle device 60 side, it becomes possible to sufficiently secure the reaction time of the cenosphere that burns the cenosphere particles on the downstream side behind the flame 81 whose length is shortened, and suppresses the generation of dust. Or can be reduced.

  When the low-quality oil fuel 200a containing residual carbon is burned, a part of the residual carbon becomes dust through the cenosphere particles, so that the length of the flame 81 is shortened and the cenosphere on the downstream side behind the flame 81 is reduced. If the reaction time of the cenosphere where the particles are burned is ensured, soot particles generated by the burning of the cenosulfa particles can be reduced to about 50% compared to the conventional case.

  In the fuel spray nozzle device 60, the spray air 103 a is also supplied to the four spray nozzles 72 installed by pressure balance in the body 61 through the spray air flow path 203 and the distribution spray air flow path 204, and the spray air. The fuel is distributed to the spray air 103a supplied to the combustion air holes 65 that suppress the generation of soot formed at the tip of the fuel spray nozzle device 60 through the flow path 203 and the distribution spray air flow path 205.

  As described above, in the four spray nozzles 72 installed, the fuel nozzle 70 installed on the axial center side for ejecting the low quality oil fuel 200a to the spray nozzle 72 and the spray for ejecting the spray air 103a to the outer peripheral side of the fuel nozzle 70. As a result of providing the air supply nozzle 71, the shearing force by the spray air 103a injected from the spray air supply nozzle 71 to the low quality oil fuel 200a is applied to the low quality oil fuel 200a by the relative speed with the low quality oil fuel 200a. The low quality oil fuel 200a ejected from the fuel nozzle 70 is atomized.

  The atomized low quality oil fuel 200a is injected from the tip of the spray nozzle 72 into the combustion chamber 3a.

  That is, by providing a plurality of spray nozzles 72 having a structure in which the fuel spray nozzle device 60 includes the fuel nozzle 70 and the spray air supply nozzle 71, the relative speed of the atomizing spray air 103a and the low quality oil fuel 200a is ensured. However, since the fuel flow rate of the low quality oil fuel 200a per spray nozzle 72 is reduced, the length of the flame 81 formed by burning the low quality oil fuel 200a in the combustion chamber 3a can be shortened.

  By shortening the length of the flame 81, the position of the sprayed low quality oil fuel 200a that reaches the axial center of the combustion chamber 3a is shifted closer to the fuel spray nozzle device 60 side, so that the low quality oil fuel 200a burns. It is possible to sufficiently secure the reaction time of the cenosphere that burns the cenosphere particles on the downstream side behind the flame 81 to be formed, and the generation of soot can be suppressed or greatly reduced.

  FIG. 3 shows a front view of the fuel spray nozzle device 60. The fuel spray nozzle device 60 includes four spray nozzles 72 having a fuel nozzle 70 and a spray air supply nozzle 71 in the circumferential direction. The combustion air holes 65 for suppressing soot are formed in the vicinity of the central portion in the radial direction of the tip portion of the fuel spray nozzle device 60.

  Further, the combustion air 102a supplied to the combustion chamber 3a is burned into the combustion chamber 3a at the front end portion of the fuel spray nozzle device 60 on the outer peripheral side of the four spray nozzles 72 arranged in an annular shape. A swirler 52 that generates a swirling flow for holding the flame is disposed.

  The low quality oil fuel 200a ejected from the spray nozzle 72 of the fuel spray nozzle device 60 is mixed with the combustion air 102a supplied from the air swirler 52 provided on the outer peripheral side of the fuel spray nozzle device 60, and the fuel spray nozzle device. 60 is injected into the combustion chamber 3a of the gas turbine combustor 3 from the front end of the gas turbine combustor 3 and burns. The swirl flow of the combustion air 102a supplied to the combustion chamber 3a by the air swirler 52 causes the inside of the combustion chamber 3a to Thus, the flame 81 formed by the combustion of the low quality oil fuel 200a is held by forming a circulating flow in the low speed region near the tip of the fuel spray nozzle device 60.

  The fuel concentration of the low quality oil fuel 200a sprayed from the fuel nozzle 70 of the spray nozzle 72 is increased in the combustion chamber 3a facing the inner peripheral side of the four spray nozzles 72 arranged annularly in the fuel spray nozzle device 60. .

  Therefore, the atomizing air 103a is supplied from the combustion air hole 65 formed at the center in the radial direction of the tip of the fuel spray nozzle device 60 in the axial direction of the combustion chamber 3a to increase the oxygen concentration, thereby increasing the oxygen concentration in the combustion chamber 3a. Since the fuel concentration at the axial center of the fuel cell is improved so as to be low, generation of soot can be suppressed.

  Since the spray air 103a for suppressing soot dust uses the spray air 103a distributed by the pressure balance from the spray air 103a whose supply pressure is higher than the normal combustion air 102a inside the fuel spray nozzle device 60, the spray air 103a is sprayed. There is no need to increase the area of the flow path for supplying the combustion air hole 65 for injecting the air 103a or the combustion air 102a, and the combustion air 103a having the same size as the conventional fuel spray nozzle device 60 and suppressing dust is used. It is possible to supply.

  Next, FIG. 4 shows the relationship between the residual carbon contained in the fuel used in the gas turbine combustor 3 and the concentration of dust in the combustion gas generated when this fuel is burned.

  FIG. 4 shows the change in the soot concentration due to the residual carbon in the fuel under the same gas turbine load condition. From FIG. 4, the soot concentration in the combustion gas generated as the residual carbon concentration in the fuel increases. You can see it gets higher.

  Here, the reason why the concentration of soot in the combustion gas generated with the increase in the residual carbon concentration in the fuel is high is that a part of the residual carbon is sprayed on the combustion chamber 3 a of the gas turbine combustor 3. Since a shell is formed on the surface of the fuel, it takes longer to evaporate and vaporize the droplets compared to normal fuel droplets. In addition, after the droplets evaporate, the cenosphere remains and the remaining cenosphere burns the gas turbine. The cause is considered to remain at the outlet of the vessel 3 without being burned out.

  However, once the cenosphere is generated, the cenosphere has the property of disappearing by securing the time for the cenosphere to burn.

  FIG. 5 shows the relationship between the residence time of the combustion gas in which the fuel burns and stays in the combustion chamber 3a, and the soot concentration in the combustion gas.

  FIG. 5 is based on the length of a normal gas turbine combustor 3 and increases the length of the combustion chamber of the gas turbine combustor 3 without changing the air distribution of the gas turbine combustor 3 and the position of the combustion air hole. The state of the change of the dust concentration at the combustor outlet at this time is represented by the residence time of the combustion gas in the combustion chamber 3a.

  As shown in FIG. 5, the relationship between the residence time of the combustion gas in the combustion chamber 3 a of the gas turbine combustor 3 and the soot concentration, the residence time of the combustion gas is compared with the soot concentration measured at the reference position at the combustor outlet. It can be seen that the longer the length, the lower the concentration of generated dust.

  This is considered to be because the time required for the reaction of senospha generated by combustion can be secured by increasing the residence time of the combustion gas.

  Further, it has been found that senospha reacts even under conditions close to the combustor outlet temperature supplied with the diluted air of the gas turbine combustor 3. The temperature in the vicinity of the combustor outlet is lower than 1500 ° C., which is said to generate NOx, and ensuring the residence time of the combustion gas in the vicinity of the combustor outlet makes it possible to reduce the dust without increasing NOx. It is effective in reducing the concentration.

  From the above description, it can be understood that securing sufficient residence time of the combustion gas in the vicinity of the combustor outlet is important for the reduction of cenosphere.

  In other words, in order to ensure the residence time of the combustion gas in the vicinity of the combustor outlet in order to reduce the concentration of dust, the low quality sprayed from the fuel spray nozzle device 60 in the combustion chamber 3a of the gas turbine combustor 3 is used. If the length of the flame 81 formed by the combustion of the oil fuel 200a is shortened, a reaction region of the cenosphere that burns the cenosphere particles is created on the downstream side of the rear part of the flame 81 whose length is shortened, and the combustor This means that a sufficient residence time of the combustion gas in the vicinity of the outlet can be secured.

  As described above, in the gas turbine combustor 3 according to the present embodiment, the gas turbine combustor 3 is used in order to use the low quality oil fuel 200a having more residual carbon than light oil or heavy fuel oil A as a fuel as part of fuel diversification. The installed fuel spray nozzle device 60 has a fuel nozzle 70 for injecting the low quality oil fuel 200a into the combustion chamber 3a, and a spray air supply for injecting the spray air 103a for refining the low quality oil fuel 200a to the outer peripheral side of the fuel nozzle 70. A plurality of spray nozzles 72 each having a nozzle 71 are installed.

  Further, a combustion air hole 65 for spraying spray air in the axial direction in the combustion chamber 3 a is formed at the center of the tip of the fuel spray nozzle device 60 in the radial direction, and combustion is performed on the outer peripheral side of the tip of the fuel spray nozzle device 60. By providing each swirler 52 for swirling the working air, a plurality of flames 81 in which the low-quality oil fuel 200a is burned are formed in the combustion chamber 3a, so that the temperature in the region in the combustion chamber 3a in contact with the adjacent flame 81 The decrease is reduced and the evaporation of the droplets of the low quality oil fuel 200a is promoted.

  Further, since a plurality of spray nozzles 72 for spraying fuel are provided, the low quality sprayed into the combustion chamber 3a in order to reduce the fuel flow rate of the low quality oil fuel 200a borne by each spray nozzle 72. The arrival position of the oil fuel 200a is shifted to the fuel spray nozzle device 60 side, and the length of the flame 81 can be shortened.

  In addition, a combustion air hole 65 for ejecting the spray air 103a in the axial direction of the combustion chamber 3a is provided at the center in the radial direction of the tip of the fuel spray nozzle device 60 on the inner peripheral side of the plurality of spray nozzles 72 provided. Thus, the fuel rich region in the axial center of the combustion chamber 3a in the vicinity of the flame 81 is improved to suppress the generation of soot.

  As described above, by shortening the length of the flame 81 formed in the combustion chamber 3 a, the cenosphere (residue derived from residual carbon) once generated by the combustion of the low quality oil fuel 200 a in the combustion chamber 3 a is also behind the flame 81. It is possible to sufficiently secure the reaction time of cenosphere that the cenosphere particles burn in the high-temperature combustion gas atmosphere on the downstream side of the section, and the generation of soot can be suppressed or greatly reduced.

  Therefore, even when the low-quality oil fuel 200a is used as the fuel, it is possible to suppress or reduce the concentration of dust generated when the fuel is burned without increasing the length of the gas turbine combustor 3.

  According to an embodiment of the present invention, when low quality oil is used as a fuel for a gas turbine combustor, combustion stability is ensured in the operating load range of the gas turbine, and the concentration of dust generated during combustion of the low quality oil is reduced. A gas turbine combustor can be realized.

  The present invention is applicable to a gas turbine combustor that wants to reduce the generation of soot when using a low quality oil fuel containing residual carbon.

1 is a schematic system diagram showing a gas turbine power plant including a gas turbine combustor that is an embodiment of the present invention. The partial expanded sectional view of the fuel spray nozzle apparatus with which the gas turbine combustor of the Example shown in FIG. 1 was equipped. The front view of the fuel spray nozzle apparatus shown in FIG. The characteristic view which shows the relationship between the residual carbon in a fuel and dust concentration in a gas turbine combustor. The characteristic view which shows the relationship between the residence time of the combustion gas in a gas turbine combustor, and a dust concentration.

Explanation of symbols

  1: Gas turbine power plant, 2: Air compressor, 3: Gas turbine combustor, 3a: Combustion chamber, 4: Turbine, 6: Generator, 8: Motor for start-up, 10: Outer cylinder, 11: Combustion chamber liner 14: Booster compressor, 15: Pressure control valve, 52: Swirler, 60: Fuel spray nozzle device, 61: Nozzle body, 65: Combustion air hole, 70: Fuel nozzle, 71: Spray air supply nozzle, 72: Spray nozzle, 81: flame, 102: combustion air system, 102a: combustion air, 103: spray air system, 103a: spray air, 104: spray steam system, 104a: spray steam, 110: combustion gas flow path, 110a : Combustion gas, 200: Low quality oil fuel system, 200a: Low quality oil fuel, 201: Fuel flow path, 202: Distribution fuel flow path, 203: Spray air flow path, 204, 205: Distribution spray air flow , 301: shutoff valve, 302: flow rate control valve.

Claims (5)

  In a gas turbine combustor that uses a low-quality oil fuel containing residual carbon as a gas turbine fuel, a fuel spray nozzle device that injects the low-quality oil fuel into the combustion chamber is installed in the gas turbine combustor. A swirler that swirls part of the combustion air supplied to the gas turbine combustor and flows into the combustion chamber is provided on the side, and a combustion air hole that ejects spray air into the combustion chamber is provided at the center in the radial direction. The fuel spray nozzle device includes a fuel nozzle that ejects low-quality oil fuel, and a spray air supply nozzle that is installed on the outer peripheral side of the fuel nozzle and ejects spray air that refines the low-quality oil fuel injected from the fuel nozzle. A gas turbine combustor comprising: a plurality of spray nozzles each having a nozzle disposed on an outer peripheral side of a combustion air hole.   2. The gas turbine combustor according to claim 1, wherein a fuel spray nozzle device installed in the gas turbine combustor includes a fuel flow path for flowing down the low quality oil fuel supplied from an external low quality oil fuel system, and the fuel flow. A distribution fuel flow path for flowing low quality oil fuel distributed from the passage to a fuel nozzle provided in the spray nozzle and a spray air flow path for flowing the spray air supplied from an external spray air system And a distribution spray air flow path for allowing the spray air distributed from the spray air flow path to flow down to the spray air supply nozzle provided in the spray nozzle.   The gas turbine combustor according to claim 2, wherein the fuel spray nozzle device installed in the gas turbine combustor is provided with spray air distributed from the spray air flow path at a central portion in a radial direction of the fuel spray nozzle device. A gas turbine combustor characterized in that another distribution spray air flow path is formed to flow down to the combustion air hole.   The gas turbine combustor according to claim 2, wherein a swirler is installed in a distribution spray air flow path of a spray air supply nozzle provided in a spray nozzle provided in a fuel spray nozzle device installed in the gas turbine combustor. A gas turbine combustor.   2. The gas turbine combustor according to claim 1, wherein a plurality of spray nozzles installed in a fuel spray nozzle device installed in the gas turbine combustor are supplied from a low-quality oil fuel supplied from the fuel nozzle and a spray air supply nozzle. A gas turbine combustor, wherein the gas turbine combustor is disposed so as to face the combustion chamber so that the sprayed air is jetted into the combustion chamber together.

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