JP3960222B2 - Gas turbine combustor, fuel injection nozzle for gas turbine combustor, and fuel injection method for gas turbine combustor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas turbine combustor, a fuel injection nozzle thereof, and a fuel injection method for the gas turbine combustor.
[0002]
[Prior art]
As a technique for atomizing fuel when a liquid fuel is burned by a gas turbine combustor, a technique using a dual orifice type liquid fuel injection nozzle can be cited (see Patent Document 1). This nozzle increases the supply pressure of the fuel injected from the pilot nozzle even when the fuel flow rate is low during ignition and the subsequent warm-up / acceleration process, and atomizes the fuel by pressure spraying. It is intended for stability. Further, a main nozzle is disposed concentrically on the outer peripheral side of the pilot nozzle.
[0003]
[Patent Document 1]
JP 2000-320836 A
[0004]
[Problems to be solved by the invention]
In the dual-orifice liquid fuel injection nozzle, after the fuel supply to the main nozzle is started, most of the fuel flow rate injected into the combustion chamber is handled by the main nozzle. Therefore, the nozzle pressure of the main nozzle mainly determines the fuel supply pressure. However, if the pilot nozzle differential pressure (pressure difference between the nozzle pressure and the combustion chamber pressure) is increased in order to atomize the pilot nozzle, and the crack pressure of the pressurization valve is increased, the pressurization valve pressure is Therefore, the fuel supply pressure is inevitably increased, and the discharge pressure of the fuel supply pump needs to be increased. As a result, the equipment becomes larger and the economy is reduced. In addition, increasing the nozzle pressure of the pilot nozzle for atomization leads to a reduction in the nozzle orifice area of the nozzle orifice, which is an undesirable direction from the viewpoint of ensuring reliability and ease of quality control.
[0005]
An object of the present invention is to achieve atomization of fuel and simplification of equipment in a dual orifice type fuel injection nozzle.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides: An introduction air passage for introducing air into the main nozzle passage downstream of the first pressurizing valve, and means for supplying air to the introduction air passage from the time of ignition of the gas turbine to the middle of the speed increase And a second pressurizing valve for preventing fuel from entering the introduction air flow path in the introduction air flow path. It is provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The dual orifice type liquid fuel injection nozzle provided with means for introducing air into the supply flow path of the main nozzle according to the present invention is used by being incorporated in a gas turbine combustor as shown in FIG. One of the important issues when burning liquid fuel in a gas turbine combustor is atomization of the fuel. If a fuel injection nozzle with poor atomization characteristics is used, there is a high possibility that ignition failure or white smoke will be generated due to unburned fuel when starting up the gas turbine. A local metal temperature rise may become a problem. Therefore, in the dual orifice liquid fuel injection nozzle according to the present invention, the fuel flow path reaching the fuel injection port is divided into the pilot fuel and the main fuel, and the nozzle orifice for injecting the fuel into the combustion chamber is also the pilot nozzle and the main fuel. It is separated from the nozzle. These nozzle orifices are arranged concentrically (annularly) so that the pilot nozzle is inside, and are configured close to the fuel outlet. A pressurizing valve is arranged on the upstream side of the main nozzle, and when the fuel flow rate is small and therefore the fuel supply pressure is low, only pilot fuel is injected from the fuel injection port, the fuel flow rate is increased and the fuel supply pressure is set. When the pressure (crack pressure) is reached, the pressurization valve opens and both pilot fuel and main fuel are injected from the fuel injection port. The pilot fuel and the main fuel are mixed when ejected from the fuel injection port. Before reaching each nozzle orifice, the fuel is swirled in the nozzle and injected into the combustion chamber as fine droplets having an injection angle from the fuel injection port. The present invention relates to fuel atomization at the time of ignition intended for a dual orifice type liquid fuel injection nozzle and subsequent warm-up / acceleration process, and the process is performed in combination with the atomization method based on the shear force of air flow. New proposals to further improve the atomization of fuel.
[0008]
The crack pressure will be described. When the fuel flow rate is low and therefore the fuel supply pressure is low, only pilot fuel is injected from the fuel injection port.When the fuel flow rate increases and the fuel supply pressure reaches a certain set pressure, the pressurization valve opens and the pilot fuel and main fuel Both are injected from the fuel injection port. The nozzle differential pressure when the pressurizing valve opens is defined as the crack pressure.
[0009]
First, an embodiment of a gas turbine combustor according to the present invention will be described with reference to FIG. A plurality of cans of the gas turbine combustor 2 of this embodiment are arranged around a gas turbine (not shown). Each combustor 2 has at least a fuel injection nozzle 1 and a combustion chamber liner 3. The combustion chamber liner 3 is provided with combustion holes 4a, 4b, 4c, 4d for ejecting combustion air. However, the number and arrangement of the combustion holes 4a, 4b, 4c, 4d are not particularly limited.
[0010]
The combustion air 10 is supplied to the combustor 2 from a compressor (not shown). Then, it flows into the combustion chamber liner 3 from the combustion holes 4 a, 4 b, 4 c, 4 d in the process of flowing along the combustion chamber liner 3. Further, a part 10 a of the combustion air 10 reaches the vicinity of the fuel injection nozzle 1. An air swirler 80 is disposed in the fuel injection nozzle 1, and combustion air 10a is also ejected from this portion.
[0011]
As for the liquid fuel, pilot fuel 20 a and main fuel 20 b are supplied to the fuel injection nozzle 1 and injected into the combustion chamber 5. The pipes of the pilot fuel 20a and the main fuel 20b are connected on the upstream side. In the combustion chamber 5, a circulating flow is formed by the combustion air 10 described above, and a stable diffusion combustion flame is formed by mixing with the injected liquid fuels 20a and 20b. Combustion gas discharged from the combustion chamber 5 is sent to a turbine (not shown) to drive the turbine.
[0012]
In the configuration of the dual orifice type liquid fuel injection nozzle, the nozzle orifice area of the pilot nozzle is made smaller than that of the main nozzle, and the nozzle differential pressure (pressure difference between the nozzle pressure and the combustion chamber pressure) with respect to the fuel flow rate is increased. . The orifice shape indicates a shape in which the cross-sectional area of the flow path becomes narrower as the flow path advances. Since the particle size of the fuel injected from the fuel injection port tends to be smaller as the nozzle differential pressure is larger, the particle size of the fuel droplet ejected from the pilot nozzle is smaller than the fuel droplet from the main nozzle.
[0013]
On the other hand, particularly when the gas turbine combustor is ignited and when it is warmed up, it is necessary that fuel with a fine particle size be injected into the combustion chamber. This is because if the fuel particle size is large at the time of ignition when the combustion air temperature is low, even if the fuel around the spark plug can be ignited by the spark plug, there is not enough combustible fuel vapor in the surrounding area to propagate the flame. Without stopping the operation of the spark plug, the flame will blow out. Also, when operating at a fuel flow rate smaller than the ignition fuel flow rate during warm-up, if the fuel particle size is large, the supply of combustible fuel vapor to the flame holding region, which is necessary for the stable formation of the flame, is not possible. The possibility of the flame blowing out increases because it becomes sufficient.
[0014]
In order to cope with these possible problems, in the dual orifice type liquid fuel injection nozzle, the fuel injection pressure of the pilot nozzle is increased to atomize the fuel. When the ignition and warm-up process ends and the turbine speed increases, the combustion air flow rate, fuel flow rate, and combustion air temperature rise, so the amount of combustible fuel vapor supplied to the flame holding region increases. . In such a state, when the pressure valve arranged on the upstream side of the main nozzle is set to be opened and fuel is supplied to the main nozzle, a large droplet of fuel droplets is ejected from the main nozzle, but a flame is generated. It will never blow out. After the fuel supply to the main nozzle is started, the main nozzle takes charge of most of the fuel flow rate injected into the combustion chamber. Therefore, the nozzle pressure of the main nozzle mainly determines the fuel supply pressure. However, if the pilot nozzle differential pressure is increased in order to atomize the pilot nozzle and the set pressure (crack pressure) of the pressurizing valve is increased, this pressurizing valve pressure is added to the nozzle pressure of the main nozzle. Therefore, the fuel supply pressure inevitably increases, and it is necessary to increase the discharge pressure of the fuel supply pump. In addition, increasing the nozzle pressure of the pilot nozzle for atomization leads to a reduction in the nozzle orifice area of the nozzle orifice, which is an undesirable direction from the viewpoint of ensuring reliability and ease of quality control.
[0015]
As one of the measures for solving the problems in the dual orifice type liquid fuel injection nozzle described above, an air assist type liquid fuel injection nozzle is adopted. This nozzle introduces assist air into the nozzle and atomizes the fuel by the shearing force of the air. According to this method, fuel can be ejected with a fine particle size while the fuel supply pressure is smaller than that of the dual orifice liquid fuel injection nozzle. Therefore, the nozzle outlet area can be made relatively large. Further, in this method, compared to the dual orifice type liquid fuel injection nozzle, there is a tendency that a fine particle size portion tends to be formed outside the fuel jet jetted in a cone shape (conical surface). Strong resistance to flame blowout during warm-up. Furthermore, it has a feature that the influence on the atomization characteristics such as the particle diameter and the spray angle by the fuel property is small as compared with the dual orifice type liquid fuel injection nozzle. As described above, the air assist type liquid fuel injection nozzle has many excellent characteristics as compared with the dual orifice type liquid fuel injection nozzle, but a compressor for supplying assist air to the injection nozzle is necessary. It becomes a problem. Moreover, in order not to increase the pressure ratio of the compressor for assist air, it is common to increase the pressure of air partially bypassing the discharge air of the gas turbine compressor. It is necessary to cool the near high temperature air to about 100 ° C. This is a measure for satisfying the required specifications for the temperature of the compressor for assist air and the temperature of the fuel injection nozzle. Since the assist air flow rate may be about 1 to 2% of the total combustion air flow rate flowing into the combustor, the heat exchange equipment for cooling becomes relatively large. For these reasons, the air assist type liquid fuel injection nozzle has a problem that the facility for supplying the assist air to the injection nozzle becomes large.
[0016]
(First embodiment)
Details of the fuel injection nozzle 1 of the first embodiment will be described with reference to FIG. As described above, the air swirler 80 is disposed in the fuel injection nozzle 1, and the combustion air 10a is ejected from this portion. The liquid fuel channel of the fuel injection nozzle 1 is divided into a pilot nozzle channel 30 and a main nozzle channel 40. The pilot nozzle flow path 30 has an opening 32 at the axial center of the end face 6 of the fuel injection nozzle via a swirler 31. On the other hand, the main nozzle channel 40 has an opening 42 on the end face 6 of the fuel injection nozzle 1 via a swirler 41. The main nozzle opening 42 is outside the pilot nozzle opening 32, and both openings are concentric (annular). Moreover, the fuel flow path leading to both openings has an orifice shape. A pressurizing valve 50 is disposed on the upstream side of the main nozzle channel 40. An introduction air passage 60 for introducing the air 15 is connected between the pressurizing valve 50 and the main nozzle passage 40. The fuel injection nozzle 1 may be provided with a fuel gas supply port and a fuel gas injection port to inject fuel gas into the combustion chamber 5. FIG. 1 shows a fuel gas supply port 70 and a fuel gas manifold 71. Is also described.
[0017]
In addition, the position which connects the introduction air flow path 60 is demonstrated. When the introduction air flow path 60 is connected to the upstream side of the pressurizing valve 50, the air 15 does not flow to the main nozzle but is introduced to the pilot nozzle. By connecting the introduction air flow path 60 to the downstream side of the pressurizing valve 50, it becomes possible to flow air to the main nozzle. For the above reasons, it is desirable to install the introduction air flow path 60 between the pressurization valve 50 and the main nozzle flow path 40.
[0018]
Next, the operation and effect of the fuel injection nozzle 1 will be described. The pilot nozzle flow path 30 and the main nozzle flow path 40 are arranged concentrically (annular) so that the pilot nozzle flow path 30 is on the inside, and are configured close to the fuel outlet. With this structure, even if the pilot nozzle pressure is large, there is little influence on the pressure acting on the jet nozzle of the main nozzle flow path 40, so that the air 15 can be introduced into the main nozzle with a relatively small pressure. For example, even if fuel is supplied to the pilot nozzle at a nozzle pressure of 1 MPa, the air 15 can be introduced to the main nozzle at a pressure of about 0.1 MPa. However, the nozzle pressure naturally depends on the area and flow rate of the nozzles. The first embodiment finds that when air is introduced into the main nozzle in this way, atomization of the fuel ejected from the pilot nozzle is promoted, and combustion stability from ignition to the middle of acceleration is improved. It is what we propose. According to studies by the inventors, even if air is introduced into the main nozzle at an air flow rate of about 0.1% of the total combustion air flow rate flowing into the combustor under these gas turbine operating conditions, the cone from the nozzle outlet It was found that a portion with a fine particle diameter was formed outside the fuel jet ejected in the shape (conical surface). It is considered that this is because the atomization of the fuel droplets is promoted by the shearing force due to the high-speed air flow by the same action as in the case of the air-assisted fuel injection nozzle described above. Further, in the first embodiment, unlike the case of the air assist type fuel injection nozzle, since the atomization is made to some extent by the pilot nozzle, the flow rate of air supplied to the main nozzle may be small and the capacity is large. No compressor is required. Moreover, there is no need to cool the atomizing air, and a large-scale heat exchanger is unnecessary. That is, the facility can be simplified. Further, according to the first embodiment, since the atomization of the pilot fuel can be improved, the nozzle pressure of the pilot nozzle and the set pressure of the pressurizing valve 50 can be reduced. This is because even if the atomization characteristics due to pressure spraying deteriorate due to the decrease in the nozzle pressure, the atomization by the air 15 ejected from the main nozzle compensates for this, and the supply of the combustible fuel vapor to the flame holding region is compensated for this. Because it is promoted, the combustion stability from ignition to the middle of the acceleration is not deteriorated. As described above, the set pressure of the pressurizing valve 50 is one of the main factors that determine the discharge pressure of the fuel supply pump. Therefore, the discharge pressure of the fuel supply pump can be reduced by reducing the set pressure, and the required power is reduced. it can.
[0019]
Next, an operation method in the gas turbine provided with the fuel injection nozzle 1 of the first embodiment will be described. In response to the start command for the gas turbine, the air 15 is introduced into the introduction air flow path 60. It is desirable that the air pressure be in a range where the pressure in the main nozzle channel 40 is 0.05 to 0.5 MPa. If the pressure is lower than this range, there is a high possibility that the variation in the flow rate of the introduced air 15 will increase for each combustor can. Further, if the pressure is higher than this range, the flow rate of the introduced air becomes large, and a large capacity air compressor is required. The supply air pressure is determined in consideration of the pressure loss of the piping reaching the introduction air flow path 60 and the pressure loss and margin of the filter, the valve and the like. For supplying air, a diesel or motor-driven compressor, a compressor driven by a belt or gear connected to a rotating shaft of a gas turbine, or the like can be used, and is not particularly limited. Further, the intake air may be directly introduced from the atmosphere, or may be extracted from an intermediate stage of the gas turbine compressor. In the latter case, since it passes through the inlet filter, suspended solids in the atmosphere are removed to some extent, and since the pressure is higher than atmospheric pressure, the required compressor power is reduced accordingly. However, regarding the removal of suspended solids in the air, it is desirable to arrange a filter or the like separately for more certainty.
[0020]
When the control setting condition is established from the start command, the spark plug is activated and the fuel 20a is supplied to the pilot nozzle passage 30. The pilot fuel 20a passes through the swirler 31 and is given a swirling motion. The pilot fuel 20a is ejected from the opening 32 and becomes fine droplets. At this time, since the air 15 is ejected from the opening 42 of the main nozzle at a high speed, the fuel droplets are further atomized. The pilot nozzle shape is designed so that the angle at which the pilot fuel 20a is sprayed (spray angle) is about 60 to 70 °. When air is introduced into the main nozzle, the air ejected from the main nozzle opening 42 hardly swells in the radial direction, and is almost axially ejected. Therefore, the substantial spray angle of the pilot fuel 20a is reduced to about 30 °, for example. This can be interpreted as that the centrifugal force of the fuel droplets ejected from the pilot nozzle is suppressed by the axial air jet from the main nozzle. The swirler and orifice shape of the main nozzle are also set so that the centrifugal force works after the fuel droplets are ejected. However, when air is introduced into the main nozzle, the spray angle is maintained because the density is small. However, sufficient centrifugal force is not generated. Thus, even if the pilot fuel spray angle is designed to be about 60-70 °, the introduction of air substantially reduces the spray angle substantially. A decrease in the spray angle can lead to poor ignition and loss of flame from the flame holding area. If so, the possibility of the flame blowing out increases when the fuel flow rate is reduced under warm-up conditions. Therefore, in the first embodiment, the swirler 80 is disposed outside the fuel injection nozzle 1. The swirler 80 is configured so that 2 to 5% of the combustion air flowing into the combustor flows. The swirling means may be a normal swirler used in a gas turbine combustor, but the mixed jet of the fuel 20a ejected from the pilot nozzle and the air 15 ejected from the main nozzle is sufficiently spread in the radial direction. It is desirable. Moreover, the jet outlet 81 of the swirler 80 faces the axial center direction of the fuel injection nozzle 1. With this arrangement, the combustion air 10a ejected from the swirler 80 once goes to the center, but immediately expands in the radial direction. At this time, the pilot fuel 20a ejected from the fuel injection nozzle 1 and the introduced air 15 are also accompanied, so that the substantial spray angle of the pilot fuel 20a can be kept within the range of 60 to 70 ° of the set value. Therefore, the effect of atomization by the air introduced into the main nozzle is maintained, and the combustion stability is further improved. As easily expected, the fuel spray angle depends on the angle of the swirler 80 and the flow rate of the combustion air 10a. However, since the pilot fuel 20a is atomized by the effect of the air 15 ejected from the main nozzle opening 42 outside the fuel jet ejected in a cone shape (conical surface) from the pilot nozzle ejection port 32, the ignition characteristics are improved. The effect of the swirler 80 on is relatively small. That is, the swirler 80 disposed outside the fuel injection nozzle 1 is not particularly limited as long as the jet outlet 81 is parallel to the axial center direction of the fuel injection nozzle 1 or toward the axial center direction.
[0021]
Here, since the atomization of the pilot fuel 20a can be achieved by introducing the air 15 into the main nozzle flow path 40, the pressure of the pilot nozzle with respect to the pilot fuel flow rate is reduced, and the pressurization valve disposed on the upstream side of the main nozzle The set pressure of 50 can be reduced. For example, when atomizing the pilot fuel 20a only by pressure spraying from the pilot nozzle orifice, if the set pressure of the pressurizing valve 50 is not set to about 1.4 MPa, combustion stabilization by promoting fuel atomization during ignition and warm-up Even if the performance cannot be obtained, by introducing the air 15 into the main nozzle channel 40, even if the set pressure of the pressurizing valve 50 is 0.7 MPa or less, the atomization of the fuel and the combustion stability are improved to the same level or more. It is possible. The set pressure in the pressurizing valve 50 is a pressure loss as soon as the fuel 20b is started to be supplied to the main nozzle. Therefore, the discharge pressure of the fuel supply pump can be reduced by reducing the set pressure.
[0022]
It is desirable that the introduction of the air 15 into the introduction air flow path 60 is performed from the ignition of the gas turbine to the middle of the speed increase. By doing so, even when the flow rate of the pilot fuel 20a is reduced when the gas turbine shifts from ignition to warm-up, the fuel droplets are atomized so that combustion stability is obtained and the flame is blown off. There is no. The specific timing of stopping the introduction of the air 15 into the introduction air passage 60 is the change in the fuel supply pressure upstream of the pressurization valve 50 and the pressure in the main nozzle passage 40 with respect to the flow rate of the pilot fuel 20a, the introduction air 15 The air supply pressure, the set pressure of the pressurizing valve 50, and the like are determined. Simply, if the difference between the fuel supply pressure upstream of the pressurization valve 50 and the pressure of the main nozzle passage 40 becomes larger than the set pressure of the pressurization valve 50, the fuel starts to be supplied to the main nozzle passage 40. At this time, if the supply pressure of the introduction air 15 is sufficiently large even if the pipe pressure loss is added to the pressure of the main nozzle passage 40, the air can be continuously introduced.
[0023]
According to the first embodiment, in the dual orifice type fuel injection nozzle, the atomization of the fuel is achieved by introducing air into the main nozzle from the ignition to the middle of the acceleration, and the swirler disposed outside the fuel injection nozzle Thus, the combustion air can be swirled and the spray angle of the mixture of fuel and air ejected from the injection nozzle can be kept within an appropriate range to improve combustion stability. Further, the set pressure of the pressurizing valve arranged on the upstream side of the main nozzle can be reduced. Therefore, it is possible to stably start the gas turbine and reduce the discharge pressure of the fuel supply pump. Further, compared with the air-assisted liquid fuel injection nozzle, a large-capacity compressor is not necessary, and a large-scale heat exchanger is not necessary. That is, the facility can be simplified.
[0024]
(Second embodiment)
FIG. 2 shows a second embodiment. The difference from the first embodiment is that in addition to the first swirler 80 that swirls the combustion air disposed outside the fuel injection nozzle 1, the combustion air is brought into contact with the combustion chamber side tip 6 of the fuel injection nozzle 1. The second swirler 90 is provided to be swiveled. Hereinafter, the same parts as those in the first embodiment are denoted by the same symbols, and redundant descriptions are omitted.
[0025]
As described in the first embodiment, the air 15 is introduced into the main nozzle passage 40 from the ignition of the gas turbine to the middle of the rising speed, and the fuel injection nozzle is further provided by the swirler 80 disposed outside the fuel injection nozzle 1. When the combustion air is swirled around 1, the fuel ejected from the pilot nozzle opening 32 is atomized and the spray angle of the air-fuel mixture ejected from the fuel injection nozzle 1 is the same as when no air 15 is introduced. Can be maintained within the range. However, at this time, a part of the mixture of the fuel and the sprayed air, which is spread in the radial direction by the swirling flow of the combustion air 10a, flows backward in the upstream direction and flows to the end face 6 of the fuel injection nozzle 1 and the member 7 in the vicinity thereof. Show the tendency to collide. Due to this event, the fuel droplets that collide with the end face 6 of the fuel injection nozzle 1 and the member 7 in the vicinity thereof are intermittently combusted in this portion, so that the metal temperature of the combustor structure member fluctuates and one of the fuel components. There is a high possibility of inducing problems such as carbonization of the part and coking. Therefore, in the second embodiment, separately from the first swirling means for swirling the combustion air 10a by the swirler 80, a swirler 90 having an opening 91 toward the combustion chamber side tip 6 of the fuel injection nozzle 1. Thus, the combustion air 10a is swirled. Here, the flow rate of combustion air from the swirler 90 as the second swirl means is set smaller than the flow rate of combustion air from the swirler 80 as the first swirl means, and the total flow rate of the combustion air flowing into the combustor is set. It is about 0.1 to 1%. Further, the combustion air jet port 91 by the swirler 90 is disposed upstream of the combustion air jet port 81 by the swirler 80, and the combustion air 10 a is swirled in contact with the combustion chamber side tip 6 of the fuel injection nozzle 1. By doing so, the air-fuel mixture of the fuel 20a from the pilot nozzle and the air 15 from the main nozzle forms a layer of combustion air around the air-fuel mixture and is ejected into the combustion chamber 5. Since the combustion air flow rate by the swirler 90 is small, there is almost no effect of expanding the air-fuel mixture in the radial direction, and assists the air-fuel mixture to be ejected in the axial direction. In this state, even if the mixture is expanded in the radial direction by the combustion air generated by the swirler 80, the air-fuel mixture is already separated from the end face 6 of the fuel nozzle. The collision is greatly reduced. Therefore, problems such as metal temperature fluctuations of the combustor structural member and carbonization of a part of the fuel component and coking can be significantly suppressed.
[0026]
According to the second embodiment, the collision of the fuel droplets with the end face of the fuel injection nozzle and the members in the vicinity thereof can be greatly reduced. Therefore, there is an effect that it is possible to greatly suppress problems such as metal temperature fluctuations of the combustor structural member and part of the fuel component being carbonized and coking.
[0027]
(Third embodiment)
FIG. 4 shows a third embodiment. In the third embodiment, the pressurizing valve 100 is provided in the introduction air passage 60 connected to the main nozzle passage 40 from the second embodiment. The pressurizing valve 100 is selected with a crack pressure at which the air 15 starts to flow through the part set to 1 kPa or higher. If the crack pressure is lower than this, there is a possibility that the main fuel 20b cannot be prevented from entering the upstream side of the pressurizing valve 100. However, if the crack pressure is set excessively, the supply pressure of the introduction air 15 is unnecessarily increased. The pressurizing valve 100 is disposed in the vicinity of the main nozzle channel 40. Specifically, the check valve or pressurization valve 100 is provided in the introduction air flow path 60, but it is desirable to dispose it as close as possible to the connection position with the main nozzle flow path 40.
[0028]
In the third embodiment, the supply of fuel to the main nozzle channel 40 is started when the pressure of the pressurizing valve 50 arranged on the upstream side of the main nozzle channel 40 reaches the crack pressure. At this time, the air 15 continues to be supplied in a state where the air supply pressure is superior to the pressure increase in the main nozzle passage 40 due to the increase in the fuel flow rate. Then, when the pressure in the main nozzle channel 40 becomes equal to or higher than a certain pressure, the supply of the air 15 is stopped, but since the pressurization valve 100 is installed, the main fuel 20b cannot enter the upstream side of the pressurization valve 100. No.
[0029]
According to the third embodiment, by disposing the pressurization valve 100 in the introduction air flow path 60, it is possible to prevent fuel from entering the upstream side thereof. Therefore, a situation in which the liquid fuel 20b remains in the introduction air flow path 60 can be avoided.
[0030]
(Fourth embodiment)
FIG. 5 shows a fourth embodiment. The fourth embodiment includes a pressure sensor 110 that detects the upstream pressure of the pressurizing valve 50 disposed on the upstream side of the main nozzle from the second embodiment, and an introduction air passage 60 that is connected to the main nozzle passage 40. A valve 120 for opening and closing the flow path is provided on the upstream side. The pressure sensor 110 may be a pressure sensor that can transmit an electrical signal normally used in a gas turbine, and any pressure detection method may be used.
[0031]
In the fourth embodiment, the supply of fuel to the main nozzle is started when the pressurization valve 50 reaches the crack pressure or higher. Therefore, the upstream pressure of the pressurization valve 50 is detected by the pressure sensor 110 and applied. Before the pressure valve 50 reaches the crack pressure, the valve 120 is closed so that the fuel 20 b does not enter the upstream side of the valve 120. In addition, the pressurization valve 100 described in the third embodiment is arranged on the downstream side of the valve 120 to prevent double entry of fuel into the introduction air pipe. However, the arrangement of the pressurizing valve 100 can be omitted depending on circumstances.
[0032]
According to the fourth embodiment, the fuel supply timing to the main nozzle is detected by detecting the upstream pressure of the pressurizing valve 50, and the fuel flow path leading to the downstream side of the pressurizing valve 50 and the main nozzle before that is detected. The valve 120 that opens and closes the pipe through which air is introduced can be closed. Therefore, there is an effect that liquid fuel can be more reliably prevented from entering the introduction air pipe.
[0033]
(Fifth embodiment)
FIG. 6 shows a fifth embodiment. In the fifth embodiment, the purge air 16 is supplied to the fuel injection nozzle 1 when the gas turbine is stopped from the second embodiment. Also in the fifth embodiment, the description overlapping the above-described embodiment is omitted, and only the fuel purge with air when the gas turbine is stopped will be described.
[0034]
If the gas turbine is left with the fuel remaining in the nozzle when it is stopped, a part of the fuel may be thermally decomposed by residual heat and caulked inside the nozzle. Therefore, it is necessary to discharge the fuel in the nozzle with purge air. is there. At this time, pressurization valve 50 In order to allow sufficient purge air to flow to the main nozzle on the downstream side of the nozzle, the purge valve is arranged with the purge air pressure on the upstream side of the main nozzle 50 Therefore, it is necessary to make the pressure larger than the set pressure, and excessive purge air flows to the pilot nozzle. Therefore, in the fifth embodiment, as described above, a pressurizing valve provided for introducing air from ignition to the middle of the acceleration. 50 Purge air is introduced from the air introduction means between the downstream side of the fuel and the fuel flow path leading to the main nozzle.
[0035]
When the gas turbine is stopped, the purge air 16 is supplied to the pilot nozzle passage 30 through the on-off valve 130a according to a predetermined control. Further, the air is also supplied to the introduction air flow path 60 through the on-off valve 130b. The introduction air flow path 60 is connected to the main nozzle flow path 40, and the purge air 16 is supplied to the downstream side of the pressurization valve 50. Therefore, the fuel 20b remaining in the main nozzle passage 40 when the gas turbine is stopped can be purged with an air pressure lower than the set crack pressure of the pressurizing valve 50. A pressurization valve 140 and a pressurization valve 100 are disposed in the flow path of the purge air pipe reaching the pilot nozzle flow path 30 and the main nozzle flow path 40, respectively. These pressurization valves prevent fuel from entering the upstream side of the pressurization valve. Moreover, the flow rate of the purge air 16 supplied to the pilot nozzle channel 30 and the main nozzle channel 40 can be adjusted to an appropriate range by adjusting the respective crack pressures.
[0036]
Here, the supply means for the purge air 16 and the means for supplying the introduction air 15 to the main nozzle flow path 40 from the ignition to the middle of the speed increase may be the same compressor. Since the purge air pressure can be reduced by introducing the purge air 16 to the downstream side of the pressurizing valve 50, the introduction air 15 and the purge air 16 can be easily shared. Further, the opening / closing valve 120 for the introduced air 15 to the main nozzle flow path 40 and the opening / closing valve 130b for the purge air 16 can be shared.
[0037]
According to the fifth embodiment, the purge air pressure supplied to the main nozzle can be made smaller than the set pressure of the pressurizing valve 50. Therefore, the discharge pressure of the compressor for purge air may be small, and the purge air flow rate can be supplied in an appropriate range to both the pilot nozzle and the main nozzle.
[0038]
【The invention's effect】
According to the present invention, in the dual orifice type fuel injection nozzle, it is possible to atomize the fuel and simplify the equipment.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a fuel injection nozzle according to a first embodiment of the present invention.
FIG. 2 is a sectional view of a fuel injection nozzle according to a second embodiment of the present invention.
FIG. 3 is a cross-sectional view of a gas turbine combustor incorporating a fuel injection nozzle according to the first embodiment of the present invention.
FIG. 4 is a sectional view of a fuel injection nozzle according to a third embodiment of the present invention.
FIG. 5 is a sectional view of a fuel injection nozzle according to a fourth embodiment of the present invention.
FIG. 6 is a sectional view of a fuel injection nozzle according to a fifth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Fuel injection nozzle, 2 ... Combustor, 5 ... Combustion chamber, 10, 10a ... Combustion air, 15 ... Introduction air, 16 ... Purge air, 20a ... Pilot fuel, 20b ... Main fuel, 30 ... Pilot nozzle flow path 40 ... main nozzle flow path, 50, 100 ... pressurizing valve, 60 ... introduction air flow path, 80, 90 ... swirler, 110 ... pressure sensor, 120, 130a, 130b ... open / close valve.

Claims (5)

A pilot nozzle flow path leading to the opening of the pilot nozzle for jetting fuel, is disposed on an outer periphery of the pilot nozzle, and a main nozzle flow path leading to the opening of the main nozzle for injecting fuel, the main nozzle passage A gas turbine combustor provided with a first pressurizing valve,
An introduction air flow path for introducing air into the main nozzle flow path downstream of the first pressurization valve;
Means for supplying air to the introduction air flow path from the time of ignition of the gas turbine to the middle of the ascending speed;
A gas turbine combustor, wherein a second pressurizing valve for preventing fuel from entering the introduction air passage is provided in the introduction air passage . A pilot nozzle passage leading to an opening of a pilot nozzle that ejects fuel; and a main nozzle passage disposed on an outer periphery of the pilot nozzle and leading to an opening of a main nozzle that ejects fuel. A gas turbine combustor fuel injection nozzle provided with a first pressurizing valve;
An introduction air flow path for introducing air into the main nozzle flow path downstream of the first pressurization valve;
Means for supplying air to the introduction air flow path from the time of ignition of the gas turbine to the middle of the ascending speed;
A second pressurizing valve for preventing fuel from entering the introduction air passage is provided in the introduction air passage;
A fuel injection nozzle for a gas turbine combustor comprising a first swirler for supplying combustion air while swirling the fuel injection nozzle forward. A fuel injection nozzle for a gas turbine combustor according to claim 2,
Gas turbine combustor fuel injection nozzle, characterized in that a and a second swirler so as to pivot the combustion air in contact with the surface of the combustion chamber side front end of the fuel injection nozzle. A fuel injection nozzle for a gas turbine combustor according to claim 2,
A fuel injection nozzle for a gas turbine combustor, comprising means for detecting an upstream pressure of the first pressurizing valve arranged upstream of the main nozzle flow path . A main nozzle is disposed on the outer periphery of the pilot nozzle and the pilot nozzle, the downstream outlet of both is formed into an orifice shape, and a first pressurizing valve is disposed upstream of the main nozzle passage leading to the outlet of the main nozzle. , wherein the first pressure valve is less than the crack pressure preset is supplied fuel only to said pilot nozzle, on the cracking pressure or fuel is supplied to both of the pilot nozzle and the main nozzle, said pilot nozzle A fuel injection method for a gas turbine combustor having a combustion chamber on the downstream side,
An introduction air passage for introducing air into the main nozzle passage downstream of the first pressurization valve, and a second pressurization valve for preventing fuel from entering the introduction air passage are provided as the introduction air passage. provided on the,
A fuel injection method for a gas turbine combustor , wherein the air is introduced from the introduction air flow path from the time of ignition of the gas turbine to the middle of the speed increase.

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