JP2011058775A - Gas turbine combustor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas turbine combustor which reduces a pressure loss in coaxial nozzles and reduces NOx emission by promoting the mixure of fuel and air. <P>SOLUTION: The gas turbine combustor includes burners in which the plurality of rows of coaxial nozzles comprising a plurality of fuel nozzles and a plurality of air holes formed on an air hole plate and coaxial with the fuel nozzles are arranged annularly. A member for generating a turbulence of an air current is provided either at a tip of the fuel nozzle constituting the coaxial nozzle or within a flow passage of the air hole formed on the air hole plate where the tip of the fuel nozzle is positioned, so as to define the minimum flow passage cross sectional area of the air hole of the coaxial nozzle. The minimum flow passage cross sectional area of the air hole of the coaxial nozzle positioned in the burner arranged on the outer peripheral side out of the plurality of rows of burners is formed wider than the minimum flow passage cross sectional area of the air hole of the coaxial nozzle positioned in the burner arranged on the central side. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a gas turbine combustor.

  There is a need for a gas turbine combustor that achieves further reduction in NOx due to environmental regulations and social demands.

  In order to realize further low NOx combustion in the gas turbine combustor, it is important to avoid the flashback phenomenon simultaneously with the low NOx combustion.

  A gas turbine combustor (hereinafter referred to as a coaxial combustor) described in Japanese Patent Application Laid-Open No. 2007-232234 discloses a technology that realizes low NOx combustion and prevention of backfire.

  In the technology related to the gas turbine combustor, a large number of coaxial nozzles in which air holes for supplying combustion air to the combustion chamber and fuel nozzles for supplying fuel to the combustion chamber are arranged coaxially or close to the same axis are arranged. A gas turbine combustor having a structure is disclosed.

  In the coaxial combustor, fuel and air are evenly distributed and supplied to the combustion chamber, and the fuel and air are mixed at a short distance to prevent backfire and achieve low NOx combustion.

  A plurality of protrusions that disturb the flow of fuel and air are provided on the outer peripheral side or inner peripheral side of the fuel nozzle constituting the coaxial nozzle to promote the mixing of the fuel and air before being supplied to the combustion chamber, thereby reducing NOx. Further reduction is made.

JP 2007-232234 A

  The coaxial combustor described in Japanese Patent Application Laid-Open No. 2007-232234 is provided with a plurality of protrusions that disturb the flow of fuel and air on the outer peripheral side or inner peripheral side of the fuel nozzle in order to reduce the NOx emission amount. However, since the pressure loss is increased by these protrusions, the amount of air flowing from the compressor to the gas turbine combustor increases in the cooling air hole of the liner. Since the air used for combustion decreases and the NOx concentration increases due to an increase in the local temperature of the flame formed in the combustion chamber, there is a problem that the effect of reducing NOx emissions by facilitating the mixing of fuel and air is weakened .

  The object of the present invention is to reduce the pressure loss at the coaxial nozzle and increase the amount of combustion air supplied to the combustor even when the fuel nozzle of the coaxial nozzle is provided with projections that disturb the flow of fuel and air. Another object of the present invention is to provide a gas turbine combustor in which a conical flame is formed in a combustion chamber and the mixing of fuel and air is promoted to reduce NOx emissions.

  A gas turbine combustor according to the present invention includes a plurality of fuel nozzles for ejecting fuel, and a plurality of air holes formed on an air hole plate located on the downstream side of the fuel nozzle and coaxial with the fuel nozzle. A burner in which a plurality of the coaxial nozzles for ejecting fuel and air are annularly arranged; a fuel nozzle constituting the coaxial nozzle of the burner; and a combustion chamber for combusting the fuel and air ejected from the air holes. In the gas turbine combustor, the air flow is disturbed either at the tip of the fuel nozzle constituting the coaxial nozzle or at the air hole passage formed in the air hole plate where the tip of the fuel nozzle is located. The air of the coaxial nozzle located in the burner arranged on the outer peripheral side among the burners arranged in the plurality of rows is defined by providing a member to be defined to define the minimum flow path cross-sectional area of the air hole of the coaxial nozzle Minimum flow path cross-sectional area of, characterized in that formed to be wider than the minimum flow path cross-sectional area of the air holes of the coaxial nozzle located in the burner arranged on the center side.

  According to the present invention, even when the fuel nozzle of the coaxial nozzle is provided with a protrusion that disturbs the flow of fuel and air, the pressure loss at the coaxial nozzle is reduced and the amount of combustion air supplied to the combustor is increased. In addition, a gas turbine combustor can be realized in which a conical flame is formed in the combustion chamber and the mixing of fuel and air is promoted to reduce NOx emissions.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows the whole structure of the gas turbine apparatus of the Example of this invention. FIG. 2 is an axial sectional view showing an embodiment of a gas turbine combustor employed in the gas turbine apparatus of FIG. 1. The front view which shows the burner in the gas turbine combustor of the Example shown in FIG. Sectional drawing which shows the air hole of the burner in the gas turbine combustor of the Example shown in FIG. The front view which shows the 1st row | line air hole of the burner in the gas turbine combustor of the Example shown in FIG. FIG. 6 is an envelope diagram of air jet streamlines from the first row air holes in the gas turbine combustor shown in FIG. 5. The front view which showed the case of the other example of the 1st row | line air hole of the burner in the gas turbine combustor of the Example shown in FIG. FIG. 8 is an envelope diagram of air jet streamlines from the first row air holes of the burner in the gas turbine combustor of the embodiment shown in FIG. 7. The axial direction sectional view which shows the modification in the gas turbine combustor of the Example shown in FIG. The elements on larger scale which show the detailed structure of the coaxial nozzle of the 1st row in the gas turbine combustor of the Example shown in FIG. The figure which looked at the fuel nozzle of the coaxial nozzle of the 1st line shown in FIG. 10 from the air hole. The elements on larger scale which show the detailed structure of the coaxial nozzle of the 2nd row and the 3rd row in the gas turbine combustor of the Example shown in FIG. The figure which looked at the fuel nozzle of the coaxial nozzle of the 1st line shown in FIG. 12 from the air hole. The elements on larger scale which show the detailed structure of the modification of the coaxial nozzle of the 2nd row and the 3rd row in the gas turbine combustor of the Example shown in FIG. The figure which looked at the fuel nozzle of the coaxial nozzle of the 2nd row and 3rd row shown in FIG. 14 from the air hole. The elements on larger scale which show the detailed structure of another modification of the coaxial nozzle of the 2nd row and the 3rd row in the gas turbine combustor of the Example shown in FIG. The figure which looked at the fuel nozzle of the coaxial nozzle of the 2nd row and 3rd row shown in FIG. 16 from the air hole. The elements on larger scale which show the detailed structure of the other modification of the coaxial nozzle of the 2nd row and the 3rd row in the gas turbine combustor of the Example shown in FIG. The elements on larger scale which show the detailed structure of another modification of the coaxial nozzle of the 2nd row and the 3rd row in the gas turbine combustor of the Example shown in FIG. The axial direction sectional view which shows the other Example of the gas turbine combustor employ | adopted as the gas turbine apparatus of FIG. The elements on larger scale which show the fuel nozzle which comprises the coaxial nozzle in the gas turbine combustor of the Example shown in FIG. The axial direction sectional view which shows other Example of the gas turbine combustor employ | adopted as the gas turbine apparatus of FIG. The elements on larger scale of the fuel nozzle and air hole which comprise the coaxial nozzle in the gas turbine combustor of the Example shown in FIG. The axial direction sectional view which shows another Example of the gas turbine combustor employ | adopted as the gas turbine apparatus of FIG. The elements on larger scale of the fuel nozzle and air hole which comprise the coaxial nozzle in the gas turbine combustor of the Example shown in FIG. The burner front view which shows another Example of the gas turbine combustor employ | adopted as the gas turbine apparatus of FIG.

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

  FIG. 1 is a schematic diagram showing the overall configuration of a gas turbine apparatus that is an embodiment of the present invention.

  In FIG. 1, this gas turbine apparatus supplies a compressor 5 for compressing air, air 10 compressed by the compressor 5 and fuel introduced from the outside, and burns to generate a high-temperature combustion gas. A gas turbine combustor 1a, a turbine 6 driven by combustion gas generated by the gas turbine combustor 1a, and a generator 9 driven by the turbine 6 to generate electric power are provided.

  More specifically, the air 10 compressed by the compressor 5 passes between the diffuser 7 and the outer cylinder 2 constituting the gas turbine combustor 1a, and the combustor liner 3 installed inside the outer cylinder 2. It flows into the air flow path formed between them.

  A part of the air 10 flowing into the air flow path flows into the combustion chamber 1 formed inside the gas turbine combustor 1 a as the cooling air 20 of the combustor liner 3.

  The remainder of the air 10 flowing into the air flow path passes through the air holes 41 formed in the air hole plate 40 installed in the head of the combustor liner 3 as the combustion air 21 and is formed in the combustor liner 3. Flows into 1.

  In the gas turbine combustor 1a of the present embodiment, fuel is supplied to the gas turbine combustor 1a through the fuel supply system 12 and the fuel supply system 13, and the fuel supply system 12 and the fuel supply system 13 include a control valve 14a. It is branched from the fuel supply system 14.

  Further, the fuel supply system 12 is provided with a control valve 12a, and the fuel supply system 13 is provided with a control valve 13a, so that the flow rate of the fuel supplied individually can be controlled. Shutoff valves 12b and 13b are provided downstream of the control valve 12a of the fuel supply system 12 and the control valve 13a of the fuel supply system 13, respectively.

  FIG. 2 shows an axial sectional view of an embodiment of the gas turbine combustor 1a employed in the gas turbine apparatus according to the embodiment of the present invention shown in FIG. 1, and FIG. 3 shows the gas turbine combustor 1a of the present embodiment. The front view which looked at the air hole plate 40 from the combustion chamber 1 formed in the inside is each shown.

  In the gas turbine combustor 1a of the present embodiment shown in FIGS. 2 and 3, the burner installed at the head of the gas turbine combustor 1a includes a plurality of fuel nozzles 31 and 32, and these fuel nozzles 31 and Each of the plurality of air holes 41 formed in the air hole plate 40 is arranged coaxially with the air hole plate 40 to form a coaxial nozzle.

  The coaxial nozzles composed of the plurality of fuel nozzles 31 and 32 and the plurality of air holes 41 formed in the air hole plate 40 are arranged in a ring shape so as to reach the third to the concentric first row. A plurality of fuel nozzles 31 are annularly arranged in the first row located on the burner center side, and the second row is located on the outer periphery side of the burner relative to the first fuel nozzle 31 on the burner center side. In the third row, a plurality of fuel nozzles 32 are annularly arranged.

  In order to distribute fuel to the plurality of fuel nozzles 31 arranged in the first row on the burner center side, the fuel nozzle 31 is connected to the fuel header 15 formed inside the end cover 30, and the burner outer periphery In order to distribute the fuel to the plurality of fuel nozzles 32 arranged in the second and third rows on the side, the fuel is also applied to the fuel header 16 disposed on the outer peripheral side of the fuel header 15 inside the end cover 30. A nozzle 32 is connected.

  Fuel is supplied to the fuel header 15 through the fuel supply system 12, and fuel is supplied to the fuel header 16 through the fuel supply system 13. Since each fuel supply system 12, 13 is provided with control valves 12 a, 13 a, a plurality of fuel nozzles 31 and fuel nozzles 32 provided together are supplied to the fuel nozzle 31 and fuel nozzle 32, respectively. It is possible to control the amount of fuel supplied.

  The fuel nozzle 31 and the fuel nozzle 32 constitute a plurality of coaxial nozzles in pairs with the air holes 41 formed in the air hole plate 40.

  The fuel supplied to the fuel headers 15 and 16 is ejected from the fuel nozzles 31 and 32 to the air holes 41 of the air hole plate 40. Since the combustion air 21 also flows into the air hole 41, the fuel and air injected into the air hole 41 flow into the combustion chamber 1 formed inside the combustor liner 3 and burn to form a flame 82. .

  The high-temperature combustion gas generated in the combustion chamber 1 flows down the transition piece 4 connected to the combustor liner 3 and is supplied to the turbine 6. After the generator 9 is driven by the turbine 6 to generate power, the exhaust gas is discharged. As shown in FIG.

  FIG. 4 is an enlarged cross-sectional view of one air hole 41 constituting the coaxial nozzle formed in the air hole plate 40. The air hole 41 includes an air hole inlet portion 45, a straight pipe portion 46 parallel to the burner central axis that is the axis of the fuel nozzle 31 downstream of the air hole inlet portion 45, and an air hole downstream of the straight pipe portion 46. The flow path center axis 64 is divided with respect to an axis 63 parallel to the burner center axis on the outlet side of the plate 40 and a swivel part 47 in which the channel center axis 64 is inclined.

  The air hole inlet 45 constituting the air hole 41 forms a reduced flow path whose flow area decreases as it goes into the flow path, and contributes to a reduction in pressure loss. This reduced flow path may be a chamfered or rounded entrance corner.

In the swivel unit 47 constituting the air hole 41, the flow path center axis 64 of the air hole 41 is circumferential with respect to the axis 63 parallel to the burner center axis. inclination angle theta ₂ which the air hole 41 so as to have a directional velocity component is inclined by an angle theta ₂ is applied.

By applying the swirl angle θ ₂ inclined so as to have such a circumferential velocity component to the air hole 41 of the swirl unit 47, as shown in FIG. 2, the inside of the combustion chamber 1 of the gas turbine combustor 1 a The swirl flow 80 is formed in the swirl flow 80, and the circulation flow 81 is generated inside the swirl flow 80, so that the high-temperature combustion gas generated downstream in the combustion chamber 1 may return to the flame base. It becomes possible.

  The high-temperature combustion gas returning to the base of the flame conveys heat and active chemical species to the fuel / air mixture ejected from the air hole 41 to stably hold the flame inside the combustion chamber 1. be able to.

Next, the inner inclination angle θ ₁ of the air hole 41 formed in the air hole plate 40 will be described in detail with reference to FIGS. 5 and 6.

  FIG. 5 is a front view of the air holes 41 in the first row on the center side of the air hole plate 40 as viewed from the combustion chamber 1. Further, the flow path center axis 64 of the swivel part 47 constituting the air hole 41 is shown projected on a plane (burner end face) perpendicular to the burner center axis 100.

Here, the angle θ ₁ of the air hole 41 formed in the air hole plate 40 is defined. The angle θ ₁ is a line 65 connecting the burner central axis 100 and the center point 101 of the outlet of the air hole 41 in the shortest direction, and the jet direction from the center point 101 of the outlet of the air hole 41 of the flow path central axis 64 of the air hole 41 is the angle that the side is formed extending, referred to as the inner inclination theta ₁ of the angle theta _1.

The burner of the gas turbine combustor of present embodiment, the angle theta ₁ of the inner inclination theta ₁ of the air hole 41 formed in the air hole plate 40 is to be less than 90 °, is set to θ _{1 <90.} Here, FIG. 6 shows an envelope 102 drawn by the trajectory of the mixture jet when the jet of the mixture of fuel and air jetted from the air holes 41 in the first row is jetted into the combustion chamber 1.

  The vertical axis in FIG. 6 is the burner axial distance from the burner end face, and the horizontal axis is the radial distance from the burner central axis 100.

When the internal inclination angle θ ₁ of the air hole 41 is smaller than 90 °, the jet flow ejected from the air hole 41 into the combustion chamber 1 once flows downstream while approaching the burner central axis 100.

  Therefore, a plurality of jets flow in the vicinity of the burner while reducing the distance between them, and the circulation flow 81 formed at the center of the burner can be surrounded by the jets.

  As a result, as shown in FIG. 2, the combustion gas returned from the downstream side in the combustion chamber 1 by the circulating flow 81 formed at the center of the burner inside the combustion chamber 1 is ejected from the air hole 41 to the combustion chamber 1. It is possible to prevent the gas from passing through the jets and leaking to the outer periphery of the burner, and to prevent the combustion reaction on the upstream side of the outer periphery of the burner.

On the other hand, as in the case of air holes 41 of the air hole plate 40 shown in FIG. 7, the inner inclination theta ₁ to be greater than 90 °, in the case of setting the inner inclination theta _1> 90 has an air hole 41 The envelope 102 drawn by the trajectory of the jet of the fuel / air mixture jetted from is as shown in FIG. 8, and the jet spreads outward from the burner as the distance from the burner end surface increases.

  Therefore, the distance between the jet flow jetted from the air hole 41 to the combustion chamber 1 increases as the jet flows downstream, and as a result, part of the combustion gas returned from the downstream side in the combustion chamber 1 by the circulating flow 81 Will pass between the jets and flow to the outer periphery of the burner.

  Since high-temperature combustion gas is supplied to the outer periphery of the burner, the fuel / air mixture injected from the second row of air holes 41 and the third row of air holes 41 immediately undergoes a combustion reaction in the vicinity of the burner end face. It will end up.

Therefore, in the burner of the gas turbine combustor of the present embodiment, the gas turbine combustor is provided even when the turning angle θ ₂ is provided in at least the first row of air holes 41 among the air holes 41 formed in the air hole plate 40. Since the swirl flow 80 can be formed inside the combustion chamber 1a, it is possible to form a circulation flow 81 capable of stably holding the flame inside the swirl flow 80.

Furthermore, by setting the angle of the internal inclination angle θ ₁ to be in the range of 0 ° <θ ₁ <90 °, it is possible to prevent high-temperature combustion gas from flowing out to the outer peripheral portion.

Also, as in the burners of the gas turbine combustor 1a of the present embodiment, also be provided the turning angle theta ₂ to the air hole 41 constituting the coaxial burner in the second column is formed on the air hole plate 40 and the third column A stronger circulation flow than the circulation flow on the outer periphery side of the burner can be formed in the center of the burner, and the stability of the flame 82 formed inside the combustion chamber 1 can be enhanced.

Further, by setting the angle of the inclining angle θ ₁ formed in the second row of air holes 41 so as to be in the range of 0 ° <θ ₁ <90 °, three rows of high-temperature combustion gas in the central circulation recirculation are surely formed. It is possible to prevent the air holes 41 from reaching the eyes.

However, since the shape of the air hole 41 becomes complicated and the processing cost increases when the inner inclination angle θ ₁ and the turning angle θ ₂ are applied to the air hole 41, the embodiment of the gas turbine combustor 1a shown in FIG. As shown in the modified example, in order to simplify the structure, the air holes 41 in the third row may be formed as straight through holes without providing the inner inclination angle θ ₁ or the turning angle θ ₂ . Further, in order to further reduce the cost, the inclining angle θ ₁ and the turning angle θ ₂ may be provided only in the first row of air holes 41. That is, the inner inclination angle θ ₁ and the turning angle θ ₂ may be provided in at least the first row of air holes 41.

  Next, in the gas turbine combustor 1a of the present embodiment shown in FIG. 2, details of the combined structure of the air holes 41 and the fuel nozzles 31 constituting the first row of coaxial nozzles are shown in FIGS.

  As shown in FIGS. 10 and 11, the tip of the fuel nozzle 31 that constitutes the coaxial nozzle in the first row is inserted into the air hole inlet 45 that constitutes the air hole 41. The air 21 that has flowed into the air hole 41 from the outer peripheral side has a higher flow velocity due to a reduction in the cross-sectional area of the air hole inlet 45.

  Further, since the rib 35 is provided at the tip of the fuel nozzle 31, a strong vortex 61 can be generated in the air flow flowing on the outer peripheral side of the fuel nozzle 31, and the strong vortex 61 is injected from the fuel nozzle 31. It is possible to disperse the fuel jet 62 around it at a short distance.

  As a result, the fuel jet 62 is widely dispersed and the flow itself has a strong turbulence component, so that the fuel and air can be sufficiently mixed before reaching the outlet of the air hole 41.

  Further, in the gas turbine combustor 1 a of the present embodiment, the fuel jet flow is biased to the wall surface of the air hole 41 by providing the straight pipe portion 46 constituting the air hole 41 on the upstream side of the swirl portion 47 constituting the air hole 41. This prevents the mixing of fuel and air from being disturbed.

  As a result, the fuel concentration distribution at the outlet of the air hole 41 shown on the right side of the outlet of the air hole 41 in FIG. 10 can make the fuel and air uniform so as to draw a substantially flat curve.

  In the burner of the gas turbine combustor 1a of the present embodiment, the conical flame 82 is formed by the swirl flow 80 formed inside the combustion chamber 1 as shown in FIG. The fuel / air mixture jetted into the combustion chamber 1 from 31 immediately burns in the combustion chamber 1, but since the mixing of fuel and air has already progressed sufficiently at the outlet of the air hole 41, Emissions can be kept low.

  In the burner of the gas turbine combustor 1a of the present embodiment, examples of combinations of the fuel nozzles 32 and the air holes 41 constituting the second row and third row coaxial nozzles are shown in FIGS.

  As shown in FIGS. 12 and 13, the fuel nozzles 32 constituting the coaxial nozzles in the second and third rows are arranged at the tip of the fuel nozzle 32 in the same manner as the fuel nozzle 31 constituting the coaxial nozzle in the first row. Ribs 35 are provided.

  As a result, in the fuel nozzle 32, a vortex 61 can be generated in the air flow 21 flowing into the air hole 41 from the outer peripheral side of the fuel nozzle 32, and the fuel jet injected from the fuel nozzle 32 by the vortex 61. 62 can be distributed to the surroundings over a short distance.

Incidentally, the fuel nozzles 32 in the second row and the third row are formed so that the maximum outer diameter D ′ _{F of} the fuel nozzle 32 is smaller than the maximum outer diameter _DF of the fuel nozzle 31 in the first row shown in FIG. (D _F > D ′ _F ).

The area S _min of the minimum flow path cross section 50 of the air holes 41 in the combined structure of the fuel nozzles 32 and the air holes 41 in the second and third rows shown in FIGS. 12 and 13 is the first row shown in FIG. Combustion that flows into the air hole 41 from the outer peripheral side of the fuel nozzle 32 because it is larger than the area S _min of the minimum flow path cross section 50 of the air hole 41 in the combined structure of the fuel nozzle 31 and the air hole 41. The flow rate of the air 21 can be increased.

  In the combination structure of the fuel nozzles 32 and the air holes 41 in the second and third rows shown in FIGS. 12 and 13, the rib 35 that generates turbulence in the air flow formed at the tip of the fuel nozzle 32 becomes small. As a result, the vortex 61 generated in the air flow flowing on the outer peripheral side of the fuel nozzle 32 is reduced, and the distance from the generation area of the vortex 61 to the wall surface of the air hole 41 is increased. The fuel concentration distribution at the outlet of the air hole 41 shown on the right side of the outlet of the air hole 41 in FIG. 12 is less than that of the fuel nozzle 31 in the first row shown in FIG. Air will mix. .

In the burner of the gas turbine combustor 1a of the present embodiment, by providing the turning angle theta ₂ to the air holes 41, set 5 and the inclination angle theta ₁ among defined in FIG 6 so as to be smaller than 90 ° Since the conical flame 82 is formed by the swirl flow 80 formed inside the combustion chamber 1, the coaxial jet formed by the fuel nozzles 32 and the air holes 41 in the second and third rows is 2 There is a certain distance from the outlets of the air holes 41 in the third and third rows to the flame 82.

  As a result, fuel and air are mixed and uniformed and combusted by the turbulence due to sudden expansion at the outlet of the air hole 41 before reaching the flame 82 from the outlet of the air hole 41, so that the amount of NOx emission is reduced. Can be suppressed.

Further, when the inclining angle θ ₁ is larger than 90 °, the flame formed in the combustion chamber 1 may adhere widely to the burner end face and burns with insufficient mixing of fuel and air. There is a possibility that the amount of NOx emissions increases even when the temperature falls.

  Therefore, in the burner of the gas turbine combustor 1a of the present embodiment, a rib 35 that generates turbulence is provided at the tip of the fuel nozzles 31 and 32 so that fuel and air are mixed to reduce the NOx emission amount. Therefore, the size of the member that forms the conical flame 82 in the combustion chamber 1 to generate turbulence is minimized, and the minimum flow in the air hole 41 is achieved while realizing uniform premixed combustion of fuel and air. It is possible to reduce the flame temperature by increasing the flow rate of the combustion air 21 by increasing the road cross-sectional area.

  As a result, it is possible to reduce the NOx emission generated by the combustion of the gas turbine combustor. Moreover, since the opening area of the air flow path flowing through the nozzle portion of the gas turbine combustor can be widened, the pressure loss in the gas turbine combustor and the combustion liner can be minimized, and the efficiency of the gas turbine is reduced. Can be suppressed.

  In the burner of the gas turbine combustor 1a of the present embodiment, the outer diameter of the rib 35 provided at the tip of the fuel nozzle 32 in the second row and the third row is made smaller with respect to the fuel nozzle 31 in the first row. Although the minimum flow passage cross-sectional area in the air hole 41 is increased, only the outer diameter of the rib 35 provided at the tip of the fuel nozzle 32 in the third row is smaller than the fuel nozzle 31 in the first row. In addition, the minimum flow path cross-sectional area inside the third row of air holes 41 may be increased.

  In the burner of the gas turbine combustor of the present embodiment, the number of coaxial nozzles composed of the fuel nozzles 32 and the air holes 41 in the third row occupies half of the entire burner, so that a sufficient NOx emission reduction effect is achieved. Can be obtained.

  In the gas turbine combustor burner 1a of the present embodiment, the ribs 35 are provided at the tip ends of the fuel nozzles 32 in the second and third rows in order to mix the fuel and air, as shown in FIG. Like the fuel nozzle 32a, it may be formed in a uniform cylindrical shape up to the tip of the fuel nozzle 32a without providing the rib 35 at the tip of the fuel nozzle 32a.

  In the fuel nozzle 32a shown in FIG. 14, the air 21 flowing into the air hole 41 from the outer peripheral side of the fuel nozzle 32a flows along the fuel nozzle 32a, but peeling occurs at the edge of the tip of the fuel nozzle 32a, and the vortex 61 is generated. appear. This vortex 61 can promote the mixing of fuel and air.

  However, when the rib diameter of the fuel nozzle 31 in the first row and the outer diameter of the fuel nozzle 32a in the second or third row are the same, the vortex 61 generated by the fuel nozzle 32a becomes weaker, and the mixing promotion effect is also achieved. Get smaller.

  When the vortex generated by the fuel nozzle 32a is reduced, the pressure loss is also reduced, so that the amount of air flowing into the air hole 41 can be increased.

  Therefore, it is effective to use the fuel nozzle 32a as the fuel nozzle in the second row or the third row. Further, since the shape is simple, the processing cost of the fuel nozzle 32a can be reduced.

In addition, the third column of using the fuel nozzle of the same shape as the fuel nozzles 31 of the first row as the fuel nozzle, the second and third columns of the first row of air holes the diameter D _A of the air hole 41 by greater than 41 with a diameter D _a can be obtained the same effect as the first embodiment.

And second and third columns of air holes 41 of the enlarged pore size diameter D _A larger to the air hole 41, the second row of fuel nozzles of the first column of the fuel nozzle 31 of the same shape as the third column A configuration combined with a fuel nozzle 32b installed as a fuel nozzle 32b is shown in FIGS.

  As shown in FIGS. 16 and 17, if the size of the rib 35 provided at the tip of the fuel nozzle 32b is the same and the air flow rate through the rib 35 is approximately the same, the vortex generated by the rib 35 62 has the same strength.

  When the hole diameter of the air hole 41 is increased, the distance that the generated vortex 62 reaches the wall surface of the air hole 41 is increased, so that it is longer to sufficiently mix with the air flowing in the vicinity of the wall surface of the air hole 41. The length of the air hole 41 is required, resulting in an increase in the non-uniformity of the fuel concentration at the outlet of the air hole 41.

  On the other hand, since the area in the minimum flow path cross section in the air hole 41 increases and the amount of inflow air increases, it becomes possible to burn with a lower fuel-air ratio.

  Even if the non-uniformity of the fuel concentration at the outlet of the air hole 41 increases, the distance from the outlet of the air hole 41 to the flame 82 by forming the conical flame 82 inside the combustion chamber 1. Can take longer.

  As a result, lean premixed combustion can be performed at a low fuel-air ratio, so that NOx emissions can be reduced. In addition, the diameter of the air holes 41 in the third row may be increased with respect to the air holes 41 in the first row to enlarge the minimum flow path cross-sectional area.

  Further, using the fuel nozzle 32c shown in FIG. 18 in place of the fuel nozzle 32b is effective in reducing the NOx emission amount of the gas turbine combustor 1a.

  The fuel nozzle 32c shown in FIG. 18 employs a configuration in which a plurality of fuel injection holes 62 are provided on the side surface upstream of the rib 35 in addition to the configuration of the fuel nozzle 32b shown in FIG.

  In the fuel nozzle 32c of this structure, the fuel jet 62 is dispersed in a large number at the time of jetting, and the fuel jet 62 is supplied to the starting point where the turbulence of the air flow occurs, so that the fuel 62 is taken into the vortex 61, and the fuel Air can be mixed effectively.

  Therefore, the fuel nozzle 32c shown in FIG. 18 can achieve more uniform fuel and air than the fuel nozzle 32b shown in FIG.

  Further, if there is no difference in the outer shape of the nozzle, the pressure loss before and after the air hole 41 is the same, so that mixing can be promoted without increasing the pressure loss.

The fuel nozzle 32c may be used instead of the fuel nozzle 32b. In that case, the maximum diameter _DF of the fuel nozzles 32c in the second and third rows may be reduced and the minimum flow path cross-sectional area Smin of the air holes 41 may be increased with respect to the fuel nozzles 31 arranged in the first row. .

Since the fuel nozzle 32c has better mixing performance than the fuel nozzle 32b, the maximum diameter _DF of the fuel nozzle 32c can be made smaller than that of the fuel nozzle 32b.

  Further, instead of the fuel nozzle 32b, an obstacle 50 may be arranged inside the air hole 41 as in the fuel nozzle 32d shown in FIG. In the fuel nozzle 32 d of this configuration, the fuel jet 62 can collide with the obstacle 50 and can be dispersed in the circumferential direction of the air hole 41.

  Further, the fuel jet 62 dispersed from the fuel nozzle 32d is taken into the vortex 61 of the air flow generated downstream of the obstacle 50, so that the fuel and air are mixed effectively.

  In addition, since the fuel nozzle 32d of this configuration once causes the fuel jet 62 to collide with the obstacle 50, the fuel and air can be mixed without affecting the fuel flow rate.

  Therefore, when using a low calorie fuel with a low heat generation density that contains a large amount of hydrogen, the fuel flow rate increases, so the gas turbine combustor 1a having the fuel nozzle 33 of this configuration is effective.

  According to the present embodiment, even when the fuel nozzle of the coaxial nozzle is provided with a protrusion that disturbs the flow of fuel and air, the amount of combustion air supplied to the combustor is reduced by reducing the pressure loss at the coaxial nozzle. It is possible to realize a gas turbine combustor in which a conical flame is formed in the combustion chamber and the mixing of fuel and air is promoted to reduce NOx emissions.

  Next, another embodiment of the gas turbine combustor 1a applied to the gas turbine apparatus shown in FIG. 1 will be described with reference to FIG.

  The basic configuration of the gas turbine combustor 1a of this embodiment shown in FIG. 20 is the same as that of the gas turbine combustor 1a of the previous embodiment shown in FIGS. The description about is omitted, and only a different configuration will be described below.

In the gas turbine combustor 1a of this embodiment shown in FIG. 20, the fuel nozzle 32 has a long distance from the outlet of each air hole row of the air holes 41 to the conical flame 82 formed in the combustion chamber 1. Accordingly, the maximum diameter of the first row of fuel nozzles 31, the second row of fuel nozzles 31, and the third row of fuel nozzles 32 is configured to be gradually reduced. When the maximum diameters of the fuel nozzles 31 in the 31st and 2nd rows and the fuel nozzle 32 in the 3rd row are D _F1 , D _F2 , and D _F3 , respectively, they are formed so as to have a relationship of D _F1 > D _F2 > D _F3. Yes.

At this time, assuming that the minimum cross-sectional areas of the air holes 41 of the coaxial nozzles in each row of the fuel nozzles 31 and 32 are S _m1 , S _m2 , and S _m3 , respectively, the relationship is S _m1 <S _m2 <S _m3. Is formed.

  As the fuel nozzle 31 in the first row changes from the fuel nozzle 31 in the second row to the fuel nozzle 32 in the third row, the fuel concentration distribution at the outlet of the air hole 41 becomes non-uniform. Since the distance to the conical flame 82 formed inside the combustion chamber 1 becomes long, the uniform and premixed combustion can be performed on the flame surface, and the ratio of the combustion air amount can be increased to the maximum. The flame temperature can be lowered to reduce NOx emissions.

  Further, the fuel nozzle 31 and the fuel nozzle 32 are not limited to the fuel nozzles with ribs, and a configuration in which the shapes of the uniform cylindrical fuel nozzles 32a are combined up to the tip of the fuel nozzle as shown in FIG. As shown in FIG. 19, a fuel nozzle 32d having a configuration in which an obstacle 50 is disposed inside the air hole 41 may be used.

Similarly, instead of adjusting the fuel nozzle 31 and the fuel nozzle 32 side, the diameter of the air hole diameter of the air hole 41 may be adjusted for each column. At this time, if the air hole diameters of the air holes 41 in the first row, the second row, and the third row are D _A1 , D _A2 , and D _A3 , respectively, they are formed to have a relationship of D _A1 <D _A2 <D _A3. , an air hole minimum flow path cross-sectional area of the air hole 41 _may be formed such that the relationship _{S m1 <S m2 <S m3} .

  In the gas turbine combustor 1a of the present embodiment, the air volume is increased by increasing the air hole minimum flow path cross-sectional area of the air holes 41 in the second row and the third row, but the air holes 41 in the second row. More air flows into the air holes 41 in the third row.

  Therefore, when fuel is supplied uniformly to each of the second row of fuel nozzles 31 and the third row of fuel nozzles 32, the local fuel-air ratio, which is the ratio of fuel to air passing through each air hole 41, is two rows. Eyes get bigger.

  Since the total NOx emission amount can be suppressed lower when the fuel nozzles 31 in the second row and the fuel nozzles 32 in the third row have a uniform fuel-air ratio, the third row of fuel nozzles 31 than in the second row of fuel nozzles 31 can be suppressed. It is preferable to increase the fuel flow rate through the fuel nozzle 32 so that the fuel nozzles 31 in the second row and the fuel nozzles 32 in the third row have the same fuel-air ratio condition.

  In the gas turbine combustor 1a of the present embodiment, the fuel is supplied from the same fuel header 16 to the fuel nozzle 31 in the second row and the fuel nozzle 32 in the third row, so that the fuel is supplied to the fuel nozzle 32 in the third row. In order to increase the fuel flow rate, the throttle channel 37 is provided between the fuel header 16 and the outlet of the fuel nozzle 31 and the outlet of the fuel nozzle 32 as shown in FIG. It is preferable to form the fuel nozzles 32 in the third row larger than the fuel nozzles 31 in the second row.

  Further, the position of the throttle channel 37 is not limited to the position shown in FIG. 21, and may be in the middle of the outlets of the fuel nozzles 31, 32 and the channels in the fuel nozzles 31, 32.

  According to the present embodiment, even when the fuel nozzle of the coaxial nozzle is provided with a protrusion that disturbs the flow of fuel and air, the amount of combustion air supplied to the combustor is reduced by reducing the pressure loss at the coaxial nozzle. It is possible to realize a gas turbine combustor in which a conical flame is formed in the combustion chamber and the mixing of fuel and air is promoted to reduce NOx emissions.

  Next, another embodiment of the gas turbine combustor applied to the gas turbine apparatus shown in FIG. 1 will be described with reference to FIG.

  Since the basic configuration of the gas turbine combustor 1a of the present embodiment of FIG. 22 is the same as that of the gas turbine apparatus of the previous embodiment shown in FIG. 2, the description of the configuration common to both is omitted. Only different configurations will be described below.

  In the gas turbine combustor 1a of the present embodiment shown in FIG. 22, the air holes and the fuel nozzles are arranged on four rows of concentric circles.

  The first and second fuel nozzles 31 are connected to the fuel header 15, and the third and fourth fuel nozzles 32 are connected to the fuel header 16 formed on the outer peripheral side of the fuel header 15.

Further, the maximum diameter _DF of the third and fourth rows of fuel nozzles 32 is smaller than that of the first and second rows of fuel nozzles 31, and the amount of combustion air is increased by increasing the minimum air hole channel cross-sectional area. Is increasing.

  The gas turbine combustor 1a of the present embodiment is effective when forming a large flame. The arrangement of the air holes 41 and the fuel nozzles 31 and 32 in the gas turbine combustor 1a of this embodiment is four rows from the first row to the fourth row, but it is increased to 5 rows and 6 rows according to the size of the flame. May be. At this time, the fuel system may be increased from two systems.

  Further, when the flame becomes larger and the number of rows increases, the distance from the outlet of the air hole 41 to the flame 82 becomes longer in the outer circumferential row. Therefore, for example, as shown in FIG. Even if the fuel and air are not so mixed at the outlet of the air hole 41 when they are not inserted into the air hole 41, they can be mixed before reaching the flame and can be subjected to lean premixed combustion.

  In the arrangement configuration of the fuel nozzles 31 and 32 and the air holes 41 shown in FIG. 23, the minimum flow path cross-sectional area of the air holes 41 can be widened, so that NOx is reduced by reducing pressure loss and increasing combustion air. Can do.

  In the gas turbine combustor 1a of the present embodiment, the swivel angle θ is applied to all four rows of air holes 41, but the third row and fourth row air holes are the same as in the first embodiment in order to reduce the processing cost. 41 may be straight without applying the turning angle θ.

  According to the present embodiment, even when the fuel nozzle of the coaxial nozzle is provided with a protrusion that disturbs the flow of fuel and air, the amount of combustion air supplied to the combustor is reduced by reducing the pressure loss at the coaxial nozzle. It is possible to realize a gas turbine combustor in which a conical flame is formed in the combustion chamber and the mixing of fuel and air is promoted to reduce NOx emissions.

  Next, still another embodiment of the gas turbine combustor 1a applied to the gas turbine apparatus shown in FIG. 1 will be described with reference to FIG.

  The gas turbine combustor 1a of this embodiment shown in FIG. 24 has the same basic configuration as the gas turbine combustor 1a of the previous embodiment shown in FIG. 2 and FIG. The description is omitted, and only different configurations will be described below.

  In the gas turbine combustor 1a of the previous embodiment shown in FIG. 2, the high-temperature combustion gas returned from the downstream in the combustor 1 is transmitted to the outer periphery of the burner by the circulating flow 81 generated in the center of the burner in the combustor 1. By preventing this, a conical flame 82 is formed in the combustor 1.

  By the way, since the end surface of the burner is composed of a large number of air holes 41, there is a dead space between the air holes, and therefore, combustion on the downstream side of the air holes 41 in the first and second rows. A small circulating flow 84 is formed in the vessel 1, and a low flow velocity region exists between the jets ejected from the air holes 41.

  Further, there is a space between the third row of air holes 41 and the liner 3, and therefore, a circulation flow 84 is also formed in the combustor 1 on the downstream side of the third row of air holes 41.

  In the gas turbine combustor 1 a of the first embodiment shown in FIG. 2, the fuel and air are mixed by the rib 35 provided at the tip of the fuel nozzles 31, 32. Since the fuel is present near the wall surface, the fuel is also present in the circulating flow region formed in the downstream of the dead space between the air holes 41 and the low flow velocity region between the jets.

  Therefore, when burning fuel that contains a large amount of hydrogen, or when the temperature of the gas turbine rises and the temperature of the flame rises, the flame burning speed increases, and the flame propagates through the low flow rate region, causing the temperature of the burner end surface to rise. There is a possibility that

  Therefore, in the gas turbine combustor 1a of the present embodiment shown in FIG. 24 as a countermeasure when the flame burning speed is increased, the taper 38 is tapered at the tip of the second and third fuel nozzles of the gas turbine combustor 1a. The fuel nozzle 32e which gave is used.

  FIG. 25 shows details of the air holes 41 and the second and third rows of fuel nozzles 32e in the gas turbine combustor 1a of the present embodiment. As shown in FIG. 25, the tip of the fuel nozzles 32e in the second and third rows is tapered to provide a shape that does not cause turbulence in the air 21 flowing around the fuel nozzles 32e.

  Further, with respect to the air hole 41, by providing the straight pipe portion 46 upstream of the swivel portion 47 in the air hole 41, the fuel jet flow 62 ejected from the fuel nozzle 32 e to the air hole 41 is biased to the wall surface of the air hole 41. To prevent them from being ejected.

  Thus, the fuel jet 62 ejected from the fuel nozzle 32e to the air hole 41 flows inside the air hole 41 while being surrounded by the air flow 21 flowing around the fuel nozzle 32e. Since the flow path is narrow inside the air hole 41 and there is no member that generates turbulence, there is no large turbulence (vortex) that transports the fuel in the radial direction, and the mixing of fuel and air does not proceed.

  Therefore, the fuel concentration distribution at the outlet of the air hole 41 shown on the right side of the outlet of the air hole 41 shown in FIG. 25 is such that the fuel concentration in the vicinity of the wall surface of the air hole 41 in the outlet cross section of the air hole 41 is below the combustible range. .

  As a result, there is no sufficient fuel for the reaction to proceed in the low flow velocity region around the outlet of the air hole 41, and the flame can be prevented from adhering around the air hole 41.

  Further, it is possible to prevent the occurrence of flicker due to the attachment of flame to the burner outer peripheral end face.

  Further, in place of the combination of the fuel nozzle 32e and the air hole 41 shown in FIG. 25, the same effect can be obtained with a coaxial nozzle in which the fuel nozzle 33 is arranged on the upstream side of the inlet of the air hole 41 as shown in FIG. .

  According to the present embodiment, even when the fuel nozzle of the coaxial nozzle is provided with a protrusion that disturbs the flow of fuel and air, the amount of combustion air supplied to the combustor is reduced by reducing the pressure loss at the coaxial nozzle. It is possible to realize a gas turbine combustor in which a conical flame is formed in the combustion chamber and the mixing of fuel and air is promoted to reduce NOx emissions.

  Next, another embodiment of the gas turbine combustor applied to the gas turbine apparatus shown in FIG. 1 will be described with reference to FIG.

  The basic configuration of the gas turbine combustor 1a of the present embodiment in FIG. 26 is the same as that of the gas turbine combustor 1a of the previous embodiment shown in FIGS. The description is omitted, and only different configurations will be described below.

  In gas turbine equipment, it is necessary to operate a wide range of fuel-air ratio conditions from startup to rated load conditions. In the gas turbine combustor used in this gas turbine apparatus, the premixed flame has a lower NOx emission amount than the diffusion flame, but has a narrow range of fuel-air ratio conditions for stable combustion.

  Therefore, FIG. 26 shows a front view of the burner as the gas turbine combustor 1a of the present embodiment. In the gas turbine combustor 1a of this embodiment, the burner of the previous embodiment shown in FIG. 3 is used as one sector burner 90, and this sector burner 90 is arranged in a multi-shape to constitute one multi burner. is there.

  In the gas turbine combustor 1a of the present embodiment, conical flames are respectively formed on the individual sector burners 90 constituting the multi-burner. By changing the number of flames formed by the sector burner 90, it becomes easy to perform control according to the combustion load.

  Further, as the central burner, a diffusion burner may be arranged instead of the sector burner. In this case, although the NOx emission amount increases, the stability of the flame formed in the surrounding sector burner 90 is improved by using the central diffusion burner as a fire type, so that a wide load range can be stably operated.

  According to the present embodiment, even when the fuel nozzle of the coaxial nozzle is provided with a protrusion that disturbs the flow of fuel and air, the amount of combustion air supplied to the combustor is reduced by reducing the pressure loss at the coaxial nozzle. It is possible to realize a gas turbine combustor in which a conical flame is formed in the combustion chamber and the mixing of fuel and air is promoted to reduce NOx emissions.

  The present invention is applicable to a gas turbine combustor used in a gas turbine apparatus.

  DESCRIPTION OF SYMBOLS 1a: Gas turbine combustor, 1: Combustion chamber, 2: Outer cylinder, 3: Combustor liner, 4: Transition piece, 5: Compressor, 6: Turbine, 7: Diffuser, 9: Generator, 10: Compressed air 12, 13, 14: Fuel supply system, 15, 16: Fuel header, 20: Cooling air, 21: Combustion air, 22: Swirl, 30: End cover, 31, 32, 33, 34, 39: Fuel nozzle 35: rib, 36: fuel nozzle tip edge, 37: throttle flow path, 38: fuel nozzle tip taper, 40: air hole plate, 41: air hole, 45: air hole inlet part, 46: air hole straight pipe part 47: Air hole swirl part, 50: Obstacle, 61: Vortex, 62: Fuel jet, 63: Parallel axis of burner axis, 64: Central axis of air hole, 65: Center axis of burner and air hole outlet center point Line connected by 80, swirl flow, 81, 8 : Circulating flow, 82: Flame, 83: combustion gas 85: a distance from the air hole outlet to the flame, 90: Sector burner 100: burner central axis, 101: air hole outlet center point, 102: envelope.

Claims (7)

A plurality of fuel nozzles that eject fuel and an air hole plate that is formed in an air hole plate located on the downstream side of the fuel nozzle, and a plurality of air holes that are coaxial with the fuel nozzle constitute a coaxial nozzle, and the fuel and air are ejected. In a gas turbine combustor comprising a burner in which a plurality of coaxial nozzles are annularly arranged, a fuel nozzle that constitutes the coaxial nozzle of the burner, and a combustion chamber that burns fuel and air ejected from an air hole,
A coaxial nozzle is provided by providing a member for generating a turbulence in the air flow in either the tip of the fuel nozzle constituting the coaxial nozzle or the air hole passage formed in the air hole plate where the tip of the fuel nozzle is located. Defines the minimum cross-sectional area of the air hole of
Among the burners arranged in a plurality of rows, the minimum flow path cross-sectional area of the air holes of the coaxial nozzle located in the burner arranged on the outer peripheral side is the minimum of the air holes of the coaxial nozzle located in the burner arranged on the center side. A gas turbine combustor formed so as to be wider than a cross-sectional area of a flow path. The gas turbine combustor according to claim 1.
A swivel angle θ ₂ is formed in the air hole of the coaxial nozzle constituting the burner,
In the central axis of the swirling part of the air hole projected on a plane perpendicular to the burner central axis that is the axis of the coaxial nozzle, the air ejection direction side from the air hole outlet central point is the shortest between the air hole outlet central point and the burner central axis The inclining angle θ ₁ formed by the line connected by
0 ° <θ ₁ <90 °
A gas turbine combustor characterized by being set to. The gas turbine combustor according to claim 2.
Among the burners arranged in a plurality of rows, the inner inclination angle θ ₁ is formed not only in the air holes of the coaxial nozzles arranged on the center side but also in the air holes of the coaxial nozzles arranged on the outer peripheral side. Characteristic gas turbine combustor. The gas turbine combustor according to claim 2.
Among the burners arranged in a plurality of rows, the internal inclination angle θ ₁ is formed in the air holes of the coaxial nozzle arranged at least on the center side. The gas turbine combustor according to any one of claims 2 to 4,
The gas turbine combustor, wherein an outer diameter of the fuel nozzle located on the center side of the burner is formed to be larger than an outer diameter of the fuel nozzle located on the outer periphery side of the burner. The gas turbine combustor according to any one of claims 2 to 4,
A gas turbine combustor, wherein a diameter of an air hole located on a center side of the burner is formed to be smaller than a diameter of an air hole located on an outer peripheral side of the burner. The gas turbine combustor according to any one of claims 2 to 6,
A gas turbine combustor comprising a plurality of burners to constitute a multi-burner.

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