JP2013155981A - Gas turbine combustor and gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas turbine combustor that can reduce NOemission and prevent combustion loss in a premixture duct for forming a premixed gas, and to provide a gus turbine.SOLUTION: A gas turbine combustor 10 includes: a combustor liner 22 that forms a cylindrical combustion chamber 23; a pilot combustion injector 30 provided at the top of the combustor liner 22 coaxially with a center axis of the combustor liner 22; a premixture duct 40 extended along an axial direction of the combustor liner 22 on an outer circumference of the combustor liner 22 and supplying premixed air comprising fuel and air to the combustion chamber 23; and a main fuel injection part 50 provided so that a fuel injection port 51 faces an inlet opening 41 of the premixture duct 40. An end surface 52 of the main fuel injection part 50 having the fuel injection port 51 is extended to have a width T1 in one direction. The width T1 is twice a width T2 of the fuel injection port 51 or smaller, and is equal to and larger than the width T2 of the fuel injection port 51.

Description

  Embodiments described herein relate generally to a gas turbine combustor and a gas turbine.

  In a gas turbine used in a gas turbine plant, a combined cycle plant, or the like, the operating conditions are high temperature and high pressure to increase efficiency, and NOx emissions tend to increase. As a factor of NOx generation, flame temperature is dominant. Therefore, in order to suppress the generation of NOx, it is effective to lower the flame temperature.

  Premixed lean combustion is used as a combustion method that suppresses local increase in flame temperature and suppresses NOx emissions. In this premixed lean combustion, a premixed gas in which fuel and air are premixed under fuel lean conditions is burned.

  Premixed lean combustion has a drawback that the combustion range is narrow, and various devices have been made to compensate for this drawback. In the gas turbine combustor, for example, the above-described premixed lean combustion is used in combination with diffusion combustion having a wide combustion range and capable of stable combustion. Further, in order to stabilize the flame in the premixed lean combustion, the temperature in the combustion region is always set to a predetermined temperature or more, or a flame holding mechanism is provided.

  FIG. 10 is a view showing a cross section of a conventional gas turbine combustor 200. FIGS. 11 and 12 are views showing a part of a cross section of the premixing duct 214 of the conventional gas turbine combustor 200. 11 and 12, the illustration of the fuel supply system that supplies fuel to the main fuel nozzle 217 is omitted.

  As shown in FIG. 10, the gas turbine combustor 200 includes a combustor liner 211 having a pilot nozzle 210 in the center on the head side.

  The periphery of the combustor liner 211 is covered with a gas turbine outer cylinder 213, and a premixing duct 214 is provided between the combustor liner 211 and the gas turbine outer cylinder 213 to form a premixed gas composed of fuel and air. It has been. A plurality of premixing ducts 214 are provided in the circumferential direction around the combustor liner 211.

  A plurality of outlets 214 a of the premixing duct 214 are formed, and each outlet 214 a communicates with the combustion chamber 215 in the combustor liner 211. Then, the premixed gas is supplied to the combustion chamber 215 via each outlet 214a. Further, between the combustor liner 211 and the gas turbine outer cylinder 213, a high-temperature and high-pressure combustion air 216 from a compressor (not shown) flows as a flow path toward the head side of the premixing duct 214. It is functioning.

  As shown in FIGS. 11 and 12, a fuel injection hole 217a of the main fuel nozzle 217 is provided so as to face the inlet opening (upstream end) of the premixing duct 214. The fuel 218 injected from the fuel injection hole 217a and a part of the combustion air 216 flow into the premixing duct 214. A premixed gas is formed in the premixing duct 214.

  As shown in FIGS. 11 and 12, the main fuel nozzle 217 is formed of a cylindrical body having a single fuel injection hole 217a or a porous fuel injection hole 217a. In one premixing duct 214, for example, two main fuel nozzles 217 are arranged at a predetermined interval.

JP 2007-232234 A

  In the above-described conventional premixing duct 214 having the main fuel nozzle 217 having the single-hole fuel injection hole 217a, the mixing of the fuel 218 and the air 216 is not promoted, and the premixed gas having a nonuniform fuel concentration is used. May be formed. Therefore, when the premixed gas includes, for example, a portion having a fuel concentration near the stoichiometric ratio, the NOx emission amount increases.

  Further, in the above-described conventional premixing duct 214 having the main fuel nozzle 217 having the porous fuel injection hole 217a, the mixing of the fuel 218 and the air 216 is promoted. However, if the flame of the combustion chamber 215 enters the premixing duct 214 during the formation of the premixed gas, the main fuel is generated by the vortex 219 formed on the downstream side of the main fuel nozzle 217 as shown in FIG. The flame may be held downstream of the nozzle 217. If such combustion continues in the premixing duct 214, the premixing duct 214 will burn out.

  A problem to be solved by the present invention is to provide a gas turbine combustor and a gas turbine capable of reducing NOx emission and preventing the premixing duct forming the premixed gas from being burned out. It is.

  The gas turbine combustor of the embodiment includes a combustor liner that forms a cylindrical combustion chamber, a pilot fuel injection unit provided in the center of the head of the combustor liner, and the combustion on the outer periphery of the combustor liner. A premixing duct that extends along the axial direction of the liner and supplies a premixed gas comprising fuel and air to the combustion chamber, and a fuel injection port is provided to face the inlet opening of the premixing duct. A main fuel injection unit.

  An end surface of the main fuel injection portion having the fuel injection port has a width T1 and extends in one direction, and the width T1 is 2 of the width T2 of the fuel injection port in the width T1 direction. It is not more than twice and is not less than the width T2.

It is a figure showing a meridional section of a gas turbine provided with a gas turbine combustor of a 1st embodiment. It is a figure which shows the cross section of the gas turbine combustor of 1st Embodiment. It is the figure which showed typically the cross section of the main fuel injection part in the gas turbine combustor of 1st Embodiment. It is a top view when the main fuel injection part in the gas turbine combustor of a 1st embodiment is seen from the entrance opening side of a premixing duct. In the gas turbine combustor of 1st Embodiment, it is the figure which showed typically the cross section of the main fuel injection part when width T1 becomes equal to width T2. It is a top view when the main fuel injection part of another shape in the gas turbine combustor of a 1st embodiment is seen from the entrance opening side of a premixing duct. It is a top view when the main fuel injection part in the gas turbine combustor of a 2nd embodiment is seen from the entrance opening side of a premixing duct. It is a figure which shows the test result which investigated the influence which width | variety T1 has on flame holding. It is a figure which shows the test result which investigated the influence which the distance L has on NOx discharge | emission amount. It is the figure which showed the cross section of the conventional gas turbine combustor. It is the figure which showed a part of cross section of the premixing duct of the conventional gas turbine combustor. It is the figure which showed a part of cross section of the premixing duct of the conventional gas turbine combustor.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing a meridional section of a gas turbine 150 including the gas turbine combustor 10 according to the first embodiment. FIG. 2 is a diagram illustrating a cross section of the gas turbine combustor 10 according to the first embodiment. In FIG. 1, the gas turbine combustor 10 is not shown in cross section.

  As shown in FIG. 1, the gas turbine 150 mainly includes a compressor 151, a gas turbine combustor 10, and a turbine 152. In the compressor 151, air is sucked from the atmosphere and used as high-temperature and high-pressure combustion air. In the gas turbine combustor 10, fuel is mixed with combustion air from the compressor 151 and burned to generate high-temperature and high-pressure combustion gas. In the turbine 152, work is performed by passing the combustion gas generated by the gas turbine combustor 10, and rotational force is obtained. The combustion gas discharged from the gas turbine combustor 10 flows into the turbine 152 through the transition piece 153.

  The rotational force obtained by the turbine 152 is transmitted to the compressor 151 and drives the compressor 151. Further, this rotational force is transmitted to a generator (not shown) and is taken out as a shaft output. Combustion gas that has worked in the turbine 152 is exhausted from the gas turbine 150 to the outside.

  Next, the structure of the gas turbine combustor 10 of 1st Embodiment is demonstrated.

  As shown in FIG. 2, the gas turbine combustor 10 includes a combustor liner 22 that is housed in a gas turbine casing 20 and is an inner cylinder that is concentrically formed as a double cylinder in an outer cylinder 21. A pilot fuel injection unit 30 is provided at the center of the head of the combustor liner 22. The pilot fuel injection unit 30 is provided coaxially with the central axis of the combustor liner 22 at the head of the combustor liner 22, for example. Further, a transition piece 153 that guides the combustion gas to the turbine 152 is provided on the downstream side of the combustor liner 22.

  The combustor liner 22 forms a cylindrical combustion chamber 23 that generates combustion gas that drives the gas turbine 150, and forms an air passage 24 between the outer cylinder 21. The high-pressure air AR from the compressor 151 introduced from the ejection hole (not shown) of the transition piece 153 flows into the air passage 24 toward the pilot fuel injection unit 30 side. At this time, the high-pressure air AR flows while cooling the transition piece 153 and the combustor liner 22.

  The air passage 24 is provided with a premixing duct 40 extending along the axial direction of the combustor liner 22. A plurality of premixing ducts 40 are provided in the circumferential direction of the outer periphery of the combustor liner 22. Each premixing duct 40 has a plurality of outlets 42 for supplying a premixed gas composed of fuel F and air AR to the combustion chamber 23.

  A main fuel injection unit 50 that supplies fuel F into the premixing duct 40 is provided on the outer periphery of the pilot fuel injection unit 30. A fuel injection port 51 formed on an end surface of the main fuel injection unit 50 on the premixing duct 40 side is provided so as to face the inlet opening 41 of the premixing duct 40.

  The main fuel injection unit 50 and the pilot fuel injection unit 30 are accommodated in the outer cylinder 21. The main fuel injection part 50 extends from the head plate 25 to the premixing duct 40 side, and the pilot fuel injection part 30 extends from the head plate 25 to the head side of the combustor liner 22.

  For example, as shown in FIG. 2, the pilot fuel injection unit 30 includes a diffusion combustion fuel injection unit 31 for securing flame holding in the combustion chamber 23 in the center. A premixed combustion fuel injection unit 32 that injects a premixed gas in which the fuel F and the air AR are premixed into the combustion chamber 23 is provided on the outer periphery of the diffusion combustion fuel injection unit 31. A part of the combustion air AR guided to the pilot fuel injection unit 30 through the air passage 24 is introduced into the premixed combustion fuel injection unit 32 and mixed with the fuel F to form a premixed gas. ing.

  On the other hand, the remainder of the combustion air AR guided to the pilot fuel injection unit 30 side through the air passage 24 is combined with the fuel F injected from the fuel injection port 51 of the main fuel injection unit 50 and the premixing duct 40. It is led into the premixing duct 40 from the inlet opening 41. The premixed gas is introduced into the combustion chamber 23 from the plurality of outlets 42 of the premixing duct 40 and burned.

  The pilot fuel injection unit 30 and the main fuel injection unit 50 are supplied with fuel F having a predetermined flow rate from a fuel supply mechanism (not shown).

  Here, the configuration of the main fuel injection unit 50 will be described in more detail.

  FIG. 3 is a diagram schematically showing a cross section of the main fuel injection unit 50 in the gas turbine combustor 10 according to the first embodiment. FIG. 4 is a plan view of the main fuel injection unit 50 in the gas turbine combustor 10 according to the first embodiment when viewed from the inlet opening 41 side of the premixing duct 40. In FIG. 4, the shape of the inlet opening 41 of the premixing duct 40 is indicated by a broken line in order to explain the positional relationship between the main fuel injection unit 50 and the inlet opening 41 of the premixing duct 40.

  As shown in FIGS. 3 and 4, the main fuel injection portion 50 is configured by a block body extending in one direction, and includes a plurality of fuel injection ports 51 on the end surface 52. At least the end surface 52 of the main fuel injection unit 50 has a width T1 and extends in one direction.

  As described above, the premixing duct 40 is disposed concentrically with the combustor liner 22 in the circumferential direction of the combustor liner 22. Therefore, the premixing duct 40 is formed with a curvature in a direction along the circumferential direction of the combustor liner 22. Similarly to the premixing duct 40, the main fuel injection unit 50 disposed to face the inlet opening 41 of the premixing duct 40 is also arranged concentrically with the combustor liner 22. Therefore, the end surface 52 of the main fuel injection unit 50 is extended with a curvature in a direction along the circumferential direction of the combustor liner 22.

  Here, the width T1 is preferably not more than twice the width T2 of the fuel injection port 51 in the width T1 direction and not less than the width T2. When the width T1 exceeds twice the width T2, a vortex is formed downstream of the fuel injection port 51. The width T2 corresponds to the hole diameter of the fuel injection port 51. Moreover, since the end surface 52 of the main fuel injection part 50 is extended with a curvature as described above, the width T1 direction is a curvature radius direction.

  FIG. 5 is a diagram schematically showing a cross section of the main fuel injection section 50 when the width T1 is equal to the width T2 in the gas turbine combustor 10 of the first embodiment. As shown in FIG. 5, when the width T1 is equal to the width T2, the cross-sectional area of the flow path gradually increases from the upstream side (left side in FIG. 5) of the fuel injection port 51 to the fuel injection port 51 side. T1 and width T2 are equal.

  The hole diameter of the fuel injection port 51, that is, the width T2, is preferably set to about 1 mm to 5 mm. The number of fuel injection ports 51 formed in one main fuel injection unit 50 is preferably five or more. In addition, the upper limit of the number of the fuel injection ports 51 is not particularly limited, and may be restricted from the viewpoint of manufacturing, for example.

  Here, the reason why it is preferable to set the fuel injection port 51 in the above-described range will be described below. The area of the fuel injection port 51 is set based on the differential pressure between the upstream side and the downstream side of the fuel injection port 51. For example, when the area of the fuel injection port 51 is large, the above-described differential pressure is small under a condition where the fuel flow rate is small (a condition where the load of the gas turbine 150 is small). Therefore, it causes unstable combustion.

  On the other hand, when the same number of fuel injection ports 51 are provided as when the area of the fuel injection ports 51 is large, and the area of each fuel injection port 51 is reduced, the fuel injection port 51 of the gas injection port 51 is operated at the maximum load operation. The pressure on the upstream side increases and the supply pressure of the fuel F needs to be increased. Therefore, the capacity of the fuel supply mechanism that supplies the fuel F must be increased, and the cost of the apparatus increases. If the supply pressure of the fuel F is smaller than the pressure on the upstream side of the fuel injection port 51, the required fuel flow rate cannot be obtained.

  Thus, in order to obtain the optimum fuel injection port 51, it is necessary to configure the hole diameter and the number of the fuel injection ports 51 within an appropriate range. Therefore, the hole diameter and the number of the fuel injection ports 51 are set within the above-described range based on the operating conditions of the gas turbine.

  Here, it is preferable that the distance U between the fuel injection ports 51 located on both ends and the end edge 54 of the end face 52 shown in FIG. 4 is not less than 0 and not more than the width T2. When the distance U exceeds the width T2, a large reverse flow region is formed downstream of the end face 52 on the end edge 54 side. Here, when the distance U is 0, the cross-sectional area of the flow path gradually increases from the upstream side of the fuel injection port 51 toward the fuel injection port 51, and a part of the fuel injection port 51 at the end face 52 extends to the edge 54. This is the case.

  As shown in FIGS. 3 and 4, the main fuel injection unit 50 includes a center 53 (cross-sectional center) of the end surface 52 having the fuel injection ports 51, and a center 43 (cross-sectional center) of the inlet opening 41 of the premixing duct 40. Are arranged to face each other. Further, the main fuel injection unit 50 is arranged so that the extending direction of the main fuel injection unit 50 corresponds to the longitudinal direction of the inlet opening 41.

  Here, it is preferable that the end surface 52 of the main fuel injection unit 50 is positioned at 0 to 5 mm outside the premixing duct 40 (on the left side in FIG. 3) rather than the inlet opening 41 of the premixing duct 40. By configuring the end face 52 of the main fuel injection unit 50 to be in the above-described position, the flow at the inlet opening 41 of the premixing duct 40 is not disturbed, and the fuel F leaks out of the premixing duct 40. Absent.

  The case where the end face 52 of the main fuel injection section 50 is located at 0 mm outside the premixing duct 40 than the inlet opening 41 of the premixing duct 40 is when the end face 52 and the inlet opening 41 are on the same plane. It is. In this case, the center 53 of the end face 52 and the center 43 of the inlet opening 41 coincide. On the other hand, when the end face 52 of the main fuel injection section 50 is located outside the premixing duct 40 with respect to the inlet opening 41 of the premixing duct 40 (not including the case of the 0 mm position), the center 53 of the end face 52 is provided. Is a position facing the center 43 of the inlet opening 41 at a distance.

  The distance L between two points (P, Q) at which the center line M passing through the center in the width T1 direction on the end surface 52 of the main fuel injection unit 50 intersects with both end edges 54 of the end surface 52 is an extension of the center line M. Is preferably set to be 1/2 or more times the distance W between the two points (R, S) intersecting the both end edges 44 of the inlet opening 41 of the premixing duct 40.

  It is preferable to set the distance L within this range. When the distance L is less than ½ times the distance W, the mixing of the fuel F and the air AR in the premixing duct 40 is not promoted, and NOx is discharged. This is because the amount increases. The upper limit of the distance L is the distance W.

  Here, as shown in FIG. 4, an example is shown in which the end surface 52 of the main fuel injection unit 50 is extended with a curvature in a direction along the circumferential direction of the combustor liner 22. It is not limited. FIG. 6 is a plan view of the main fuel injection unit 50 having another shape in the gas turbine combustor 10 according to the first embodiment when viewed from the inlet opening 41 side of the premixing duct 40. In FIG. 6, the shape of the inlet opening 41 of the premixing duct 40 is indicated by a broken line in order to explain the positional relationship between the main fuel injection unit 50 and the inlet opening 41 of the premixing duct 40.

  As shown in FIG. 6, the main fuel injection unit 50 may be configured such that the end surface 52 of the main fuel injection unit 50 extends linearly in one direction. In this case, the center line M passing through the center in the width T1 direction is a straight line.

  In this case as well, the center 53 of the end face 52 having the fuel injection port 51 and the center 43 of the inlet opening 41 of the premixing duct 40 are arranged so as to face each other or coincide with each other. Further, the main fuel injection unit 50 is arranged so that the extending direction of the main fuel injection unit 50 corresponds to the longitudinal direction of the inlet opening 41. Since the end surface 52 of the main fuel injection unit 50 extends linearly, the width T1 direction in this case is a direction perpendicular to the extending direction of the end surface 52.

  According to the gas turbine combustor 10 of the first embodiment described above, no vortex is formed on the downstream side of the main fuel injection unit 50. Therefore, even when the flame of the combustion chamber 23 enters the premixing duct 40, the premixing duct 40 can be prevented from being burned without holding the flame downstream of the main fuel injection unit 50. Further, the mixing of the fuel F and the air AR in the premixing duct 40 is promoted, and the NOx emission amount can be reduced.

(Second Embodiment)
FIG. 7 is a plan view of the main fuel injection unit 50 in the gas turbine combustor 10 according to the second embodiment when viewed from the inlet opening 41 side of the premixing duct 40. In FIG. 7, the shape of the inlet opening 41 of the premixing duct 40 is indicated by a broken line in order to explain the positional relationship between the main fuel injection unit 50 and the inlet opening 41 of the premixing duct 40. Further, the same components as those of the gas turbine combustor 10 of the first embodiment are denoted by the same reference numerals, and redundant description is omitted or simplified.

  In the main fuel injection unit 50 in the gas turbine combustor 10 of the second embodiment, the configuration of the fuel injection port 51 is different from the configuration of the fuel injection port 51 of the main fuel injection unit 50 of the first embodiment. Therefore, this different configuration will be mainly described.

  As shown in FIG. 7, the fuel injection port 51 of the main fuel injection unit 50 is configured by a slit having a width T <b> 2 and continuously formed in the extending direction of the end surface 52. The end surface 52 of the main fuel injection unit 50 is extended with a curvature in a direction along the circumferential direction of the combustor liner 22, as in the first embodiment. For the same reason as described above, the width T1 is preferably not more than twice the width T2 of the fuel injection port 51 in the width T1 direction and not less than the width T2.

  Here, even when the fuel injection port 51 is a slit, the cross section of the main fuel injection unit 50 when the width T1 is equal to the width T2 is the upstream side of the fuel injection port 51 as shown in FIG. The channel cross-sectional area gradually increases from the left side in FIG. 5, and the width T1 and the width T2 are equal at the end face 52.

  For the same reason that the hole diameter of the fuel injection port 51 is set within a predetermined range (1 mm to 5 mm) in the first embodiment, the width T2 of the slit of the fuel injection port 51 is about 1 mm to 1.5 mm. It is preferable to set. Further, the relationship between the distance L and the distance W and the range of the distance U are the same as those in the first embodiment.

  In order to obtain the optimum fuel injection port 51, it is necessary to configure the slit width T2 and the distance L within an appropriate range. Therefore, the slit width T2 and the distance L are set within the above-described range based on the operating conditions of the gas turbine.

  Here, as shown in FIG. 7, an example is shown in which the end surface 52 of the main fuel injection unit 50 is extended with a curvature in a direction along the circumferential direction of the combustor liner 22. It is not limited. As described with reference to FIG. 6 in the first embodiment, the main fuel injection unit 50 may be configured such that the end surface 52 of the main fuel injection unit 50 extends linearly in one direction. Good.

  According to the gas turbine combustor 10 of the second embodiment described above, no vortex is formed on the downstream side of the main fuel injection unit 50. Therefore, even when the flame of the combustion chamber 23 enters the premixing duct 40, the premixing duct 40 can be prevented from being burned without holding the flame downstream of the main fuel injection unit 50. Further, the mixing of the fuel F and the air AR in the premixing duct 40 is promoted, and the NOx emission amount can be reduced.

(Effect of width T1 of main fuel injection unit 50 on flame holding)
Here, the main fuel injection unit 50 shown in FIG. 4 was used to examine the influence of the width T1 on the flame holding.

  Here, the seven fuel injection ports 51 are formed uniformly in the extending direction of the end surface 52. The distance L is 0.7 times the distance W, and the distance U is 0.95 times the width T2. The end face 52 of the main fuel injection unit 50 was set to be 0 mm from the inlet opening 41 of the premixing duct 40 to the outside of the premixing duct 40. That is, the end face 52 and the inlet opening 41 are set so as to be located on the same plane. Then, the width T1 was changed to check whether or not the flame was held downstream of the main fuel injection unit 50.

  The flow rate of fuel (natural gas) injected into the premixing duct 40 from the main fuel injection unit 50 and the flow rate of air flowing into the premixing duct 40 were set as the flow rates under the conditions of full load operation. The presence or absence of flame holding was observed visually.

  FIG. 8 is a diagram showing test results for examining the influence of the width T1 on flame holding. Here, the horizontal axis indicates the width T1 as the width T2. For example, 2 × T2 indicates that the width T1 is twice the width T2. The vertical axis represents the ratio of the flame holding range.

  The ratio of the flame holding range is based on the result of the numerical analysis by computational fluid dynamics (CFD), and the cross sectional area of the flame in the cross section perpendicular to the axial direction of the flame that holds the flame downstream of the main fuel injection unit 50. The maximum cross-sectional area of the flame in the maximum cross section is calculated, and the maximum cross-sectional area is obtained by dividing the maximum cross-sectional area by the passage cross-sectional area in the premixing duct 40 in the same cross section from which the maximum cross-sectional area is obtained.

  In the test, when the ratio of the flame holding range is equal to or less than the flame holding limit line indicated by the broken line in FIG. 8, it was confirmed that no flame holding was performed downstream of the main fuel injection unit 50. As shown in FIG. 8, it can be seen that when the width T1 is set to twice the width T2 (2 × T2), it is below the flame holding limit line. That is, it is understood that the flame is not held downstream of the main fuel injection unit 50 when the width T1 is not more than twice the width T2 and not less than the width T2.

  Although not shown here, a result similar to the result shown in FIG. 8 was obtained even when the fuel injection port 51 was formed of a slit as in the second embodiment.

(Effect of distance L of main fuel injection unit 50 on NOx emission amount)
Here, the influence of the distance L on the NOx emission amount was examined.

  The main fuel injection unit 50 shown in FIG. 4 was used as the main fuel injection unit 50, and the specifications of the fuel injection ports 51 were 2, 3, and 7. The width T1 of the main fuel injection unit 50 is set to twice the width T2. In the main fuel injection section 50, the distance U is 0.95 times the width T2, and the fuel injection ports 51 are formed uniformly in the extending direction of the end face 52.

  Moreover, the main fuel injection part 50 shown by FIG. 7 was used as the main fuel injection part 50, and the fuel injection port 51 comprised the specification of the slit. Also in this specification, the width T1 of the main fuel injection unit 50 is set to twice the width T2, and the distance U is set to 0.95 times the width T2.

  In the four types of main fuel injection units 50 described above, the influence on the NOx emission amount was examined by changing the distance L. FIG. 9 is a diagram illustrating test results obtained by examining the influence of the distance L on the NOx emission amount.

  Here, the horizontal axis indicates the distance L as the distance W. For example, 0.5 W indicates that the distance L is ½ times the distance W. The vertical axis indicates the standard deviation of the fuel concentration at the three outlets of the premixing duct 40. The smaller the standard deviation is, the more the fuel and air are mixed, the fuel concentration in the premixed gas becomes uniform, and the NOx emission amount decreases. Further, the result shown in FIG. 9 is obtained by fluid mixing analysis.

  In FIG. 9, standard deviations that do not affect the NOx emission amount when the combustor outlet temperature is 1100 ° C. (low), 1300 ° C. (medium), and 1500 ° C. (high) are indicated by broken lines. For example, when the combustor outlet temperature is 1100 ° C. (low), the standard deviation below this broken line does not affect the NOx emission amount.

  When the combustor outlet temperature is 1100 ° C. (low), the standard deviation is less than the broken line, but when the combustor outlet temperature is 1300 ° C. (medium), the standard deviation exceeds the broken line. Under the operating condition where the outlet temperature is 1300 ° C. (medium), the NOx emission amount is affected. That is, when the standard deviation is below the broken line in all temperature conditions, the NOx emission amount is not affected regardless of the combustor outlet temperature.

  As shown in FIG. 9, when there are seven fuel injection ports 51 and when the fuel injection ports 51 are slits, when the distance L is 0.5 W or more, that is, at least 1/2 times the distance W, all It can be seen that a standard deviation below the broken line of the combustor outlet temperature condition is obtained. That is, in the main fuel injection part 50 having these fuel injection ports 51, it can be understood that mixing the fuel and air can be promoted and the NOx emission amount can be reduced by setting the distance L to be 1/2 or more times the distance W. .

  According to the embodiment described above, it is possible to reduce the NOx emission amount and to prevent the premixing duct forming the premixed gas from being burned out.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... Gas turbine combustor, 20 ... Gas turbine casing, 21 ... Outer cylinder, 22 ... Combustor liner, 23 ... Combustion chamber, 24 ... Air passage, 25 ... Head plate, 30 ... Pilot fuel injection part, 31 ... Diffusion combustion Fuel injection part, 32 ... Premixed combustion fuel injection part, 40 ... Premixing duct, 41 ... Inlet opening, 42 ... Outlet, 43, 53 ... Center, 44, 54 ... Edge, 50 ... Main fuel injection part, DESCRIPTION OF SYMBOLS 51 ... Fuel injection port, 52 ... End surface, 150 ... Gas turbine, 151 ... Compressor, 152 ... Turbine, 153 ... Transition piece, F ... Fuel, AR ... Air.

Claims (7)

A combustor liner that forms a cylindrical combustion chamber;
A pilot fuel injection section provided in the center of the head of the combustor liner;
A premixing duct that extends along the axial direction of the combustor liner on the outer periphery of the combustor liner, and supplies a premixed gas composed of fuel and air to the combustion chamber;
A gas turbine combustor comprising a main fuel injection portion provided so that a fuel injection port faces an inlet opening of the premixing duct,
An end face of the main fuel injection portion having the fuel injection port has a width T1 and extends in one direction, and the width T1 is not more than twice the width T2 of the fuel injection port in the width T1 direction. And a gas turbine combustor having the width T2 or more. The center of the inlet opening of the premixing duct and the center of the end face having the fuel injection port face or coincide with each other, and the extending direction of the main fuel injection portion and the longitudinal direction of the inlet opening correspond to each other, The main fuel injection part is disposed;
The distance L between two points where the center line passing through the center in the width T1 direction on the end face of the main fuel injection portion intersects with both end edges of the end face is 2 and the extension line of the center line intersects with both end edges of the inlet opening The gas turbine combustor according to claim 1, wherein the distance is more than ½ times the distance W between the points.   3. The fuel injection port of the main fuel injection unit is formed of five or more holes that are formed uniformly in the extending direction and have a hole diameter corresponding to the width T2. The gas turbine combustor as described.   3. The gas turbine combustor according to claim 1, wherein a fuel injection port of the main fuel injection unit is configured by a slit having the width T <b> 2 and formed in the extending direction. 4.   The gas turbine combustor according to any one of claims 1 to 4, wherein an end surface of the main fuel injection portion is extended in a direction along a circumferential direction of the combustor liner.   The gas turbine combustor according to any one of claims 1 to 4, wherein an end face of the main fuel injection portion extends linearly in one direction.   A gas turbine comprising the gas turbine combustor according to any one of claims 1 to 6.

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