JP2010216669A - Gas turbine combustor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce NOx without increasing the size and cost of a gas turbine combustor. <P>SOLUTION: The gas turbine combustor includes: a main burner provided at a head of a combustion cylinder 10 forming a combustion chamber 11; and a reheating burner 40 arranged to penetrate a peripheral wall of the combustion cylinder 10. The reheating burner 40 includes: an introducing passage 50 for introducing part of the compressed air A from an air passage formed between the combustion cylinder 10 and a housing H surrounding the combustion cylinder to the combustion cylinder 10; and a fuel nozzle 43 for supplying fuel F from fuel supply holes 49 to the compressed air A introduced to the introducing passage 50 to generate pre-mixed gas M1 in the introducing passage 50. The introducing passage 50 is a turning passage for introducing the compressed air A in the air passage to the outer side in the radial direction of the combustion cylinder 10, and then, turning back the compressed air A toward the inner side in the radial direction to supply the compressed air A to the inner side of the combustion cylinder 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas turbine combustor that can suppress the amount of nitrogen oxide (hereinafter referred to as NOx) discharged even when operated at a load of a certain level or more.

  The gas turbine apparatus has strict environmental standards regarding the composition of exhaust gas discharged from the turbine during operation, and in particular, reduction of the amount of NOx contained in the exhaust gas is desired. Conventionally, as a method for reducing NOx in such a gas turbine apparatus, a method of injecting water or steam into the combustion chamber to lower the combustion flame temperature has been adopted. According to this method, the heat exchange rate of the apparatus is reduced. When the water quality is low or the quality of water used is poor, there are problems such as shortening the life of the device due to the corrosion of the turbine. As a gas turbine apparatus that overcomes these problems, there is a gas turbine apparatus that uses a DLE (Dry Low Emission) combustor that reduces NOx without using water or steam in recent years. As one form of this DLE combustor, a premix-type reheating burner is added to the downstream side of the combustion cylinder in which the main burner is installed, and the operating point of the upstream main burner is determined by NOx and unburned components. The operation is performed under the minimum condition, and further, the air and fuel are premixed from the downstream side burner, and are burned by being introduced into the combustion cylinder in which the high-temperature gas generated in the main burner exists. In addition, there are those that expand the load range without increasing unburned components (Patent Documents 1 and 2).

JP-A-8-261468 JP-A-10-196909

  However, the gas turbine devices disclosed in Patent Documents 1 and 2 extend the premixing duct from the upstream side of the combustion cylinder of the DLE combustor to the air hole for the reheating burner of the combustion cylinder. In addition to the increase in the size of the combustor itself due to a complicated structure, there has been a problem that the cost is increased due to an increase in the number of parts and the number of assembly steps.

  An object of the present invention is to provide a gas turbine combustor that can realize low NOx with a compact structure without increasing the size and cost of the combustor.

  In order to achieve the above object, a gas turbine combustor according to the present invention is a combustor that combusts compressed air and fuel supplied from a compressor and supplies them to a turbine, and includes a combustion cylinder that forms a combustion chamber. A main burner provided at the head, and a reheating burner disposed through the peripheral wall of the combustion tube on the downstream side of the combustion tube with respect to the main burner, and the reheating burner includes the combustion tube And an introduction passage for introducing a part of the compressed air into the combustion cylinder through an air passage formed between the air passage and a housing covering the same, and supplying fuel from the fuel supply hole to the compressed air introduced into the introduction passage A fuel nozzle for generating premixed gas in the introduction passage, and the introduction passage is directed radially inward after introducing compressed air in the air passage radially outward of the combustion cylinder. Fold back into the combustion cylinder A folded path for feeding. Here, the downstream side of the combustion cylinder refers to the downstream side along the flow direction of the combustion gas in the combustion cylinder.

  According to this configuration, the refueling burner is disposed downstream of the main combustion burner at the head of the combustion cylinder and downstream of the combustion cylinder, and the compressed air is supplied from the air passage formed between the peripheral wall of the combustion cylinder and the housing. This is a structure that introduces the part into the introduction passage, and is not a structure that forms a premixing duct from the head of the combustion cylinder to the air holes for the additional combustion burner on the peripheral wall of the combustion cylinder as in the prior art. Combustors can be made more compact as they become more compact. In addition, since the introduction passage into which the compressed air is introduced is a folding passage that deflects the flow of the introduced compressed air by 180 °, the compressed air is greatly disturbed during the folding. As a result, the compressed air is well agitated with the fuel supplied from the fuel supply hole to promote premixing, and a uniform premixed gas with less fuel concentration unevenness can be obtained. Since this uniform premixed gas with less concentration unevenness is combusted in the high-temperature combustion gas on the downstream side of the main burner, the amount of NOx emission can be reduced. Further, since the premixed air is given a penetrating force toward the inside in the radial direction of the combustion cylinder by the introduction passage, it is possible to prevent backfire in the introduction passage and damage the reheating burner and Since the gas sufficiently penetrates into the high-temperature combustion gas in the center of the combustion chamber, the temperature distribution at the combustor outlet is made uniform.

  In the present invention, preferably, the introduction passage includes a first passage portion that protrudes radially outward from the housing, and a second passage portion that turns back from the first passage portion and enters the combustion cylinder. . According to this configuration, the length of the passage in which the compressed air and the fuel are premixed, that is, the premixing distance between the compressed air and the fuel is increased, and the premixing of the compressed air and the fuel is further promoted.

  In the present invention, the follow-up burner has a body attached to the housing and a guide cylinder supported on the inside of the body, and the first passage portion is formed between the body and the guide cylinder. Preferably, a part of the second passage portion is formed inside the guide tube. According to this configuration, the introduction passage having a turn-back can be formed with a simple structure of a combination of the body and the guide cylinder, so that the number of parts and assembly man-hours can be reduced, and the manufacturing cost can be reduced.

  In the present invention, it is preferable that a narrowed portion having a smaller passage area than the upstream side thereof and an enlarged portion having a larger passage area than the narrowed portion are formed in the introduction passage. According to this configuration, the flow velocity of the compressed air introduced into the introduction passage at the throttle portion increases, and subsequently the flow velocity decreases at the enlarged portion. At this time, since the compressed air has a reduced dynamic pressure (an increased static pressure), the compressed air is further disturbed. Thereby, stirring of compressed air and fuel is promoted, and the concentration unevenness of the premixed gas is reduced.

  In the present invention, preferably, the first passage portion is formed with a throttle portion having a passage area smaller than the upstream side thereof, and subsequently an enlarged portion having a passage area larger than the throttle portion, so that fuel is supplied to the first passage portion. A fuel supply hole that jets into one passage portion is disposed facing the throttle portion. According to this configuration, since the static pressure of the compressed air is reduced at the throttle portion of the first passage portion, the fuel from the fuel supply hole disposed facing the throttle portion can be smoothly supplied to the first passage portion.

  In the present invention, preferably, a seal member that closes a gap between the outer periphery of the combustion tube and the inner periphery of the through hole between the downstream end portion of the guide tube and the through hole of the combustion tube through which the downstream end portion passes. Is provided. According to this configuration, by providing the seal member, it is possible to prevent the compressed air from entering the combustion cylinder through the gap between the outer periphery of the combustion cylinder and the inner periphery of the through hole.

  Further, in the present invention, the follow-up burner includes a body attached to the housing, a guide cylinder extending radially inward of the combustion cylinder, and an annular shape formed between the guide cylinder and the body. A plurality of guide pieces that are arranged concentrically with the guide tube and allow compressed air to flow into the guide tube, and so as to cover the outer periphery of the inflow port with a gap between the inflow port. It is preferable that the introduction path is formed by an inflow space between the deflection cylinder and the guide piece, an inflow space, and an inner space of the guide cylinder.

  According to this configuration, the compressed air introduced from the gap between the deflection cylinder and the inflow port is folded back 180 ° and guided to the inner space of the guide cylinder. When the compressed air is turned back, a large turbulence is generated, so that the fuel is agitated well and the premixing is promoted, and a uniform premixed gas with less fuel concentration unevenness is obtained. In addition, since the introduction passage has a structure that does not protrude outward in the radial direction of the housing, the fuel device can be made more compact.

  According to the present invention, the combustor can be made compact as the burner burner becomes compact. Further, since the introduction passage into which the compressed air is introduced is a turn-back passage that deflects the flow of the introduced compressed air by 180 °, the compressed air is greatly disturbed when turned back. As a result, the compressed air is well agitated with the fuel supplied from the fuel supply hole of the fuel nozzle to promote premixing, and a uniform premixed gas with less fuel concentration unevenness can be obtained. Since this uniform premixed gas with less concentration unevenness is combusted together with incompletely combusted fuel in the high-temperature combustion gas downstream of the main burner, the amount of NOx emission can be reduced. Further, since the premixed gas is given a penetrating force toward the radially inward direction of the combustion cylinder by the introduction passage, it is possible to prevent backfire in the introduction passage and damage the follow-up burner and Since it penetrates sufficiently into the high-temperature combustion gas at the center of the combustion chamber, the temperature distribution at the combustor outlet is made uniform.

  The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for illustration and description only, and the scope of the present invention is defined by the appended claims. In the accompanying drawings, the same reference numerals in a plurality of drawings indicate the same or corresponding parts.

1 is a schematic configuration diagram of a gas turbine power generator to which a gas turbine combustor according to a first embodiment of the present invention is applied. It is a longitudinal cross-sectional view of the gas turbine combustor concerning 1st Embodiment. The reheating burner used with the gas turbine combustor concerning a 1st embodiment is shown, (A) is the expanded longitudinal section, and (B) is the top view. The assembled state of the cap and the guide cylinder, which are constituent members of the burner, is shown, (A) is an enlarged longitudinal sectional view, and (B) is a perspective view seen from below. It is an expanded longitudinal cross-sectional view which shows the reheating burner used with the gas turbine combustor concerning 2nd Embodiment. It is a density | concentration distribution figure which shows the density | concentration distribution of the pre-mixed gas in the reheating burner exit. It is an expanded longitudinal cross-sectional view which shows the reheating burner used with the gas turbine combustor concerning 3rd Embodiment. It is a density | concentration distribution figure which shows the density | concentration distribution of the pre-mixed gas in the reheating burner exit. The reheating burner used with the gas turbine combustor concerning 4th Embodiment is shown, (A) is the expansion longitudinal cross-sectional view, (B) is the IXB-IXB sectional view taken on the line of (A). FIG. 2 shows a burn-up burner of a comparative example, in which (A) is an enlarged longitudinal sectional view, and (B) is a sectional view taken along line Xb-Xb in (A). It is a density | concentration distribution figure which shows the density | concentration distribution of the premixed gas in the reheating burner exit of the comparative example. FIG. 9 is a characteristic diagram showing the results of a combustion experiment between a combustor using the reheating burner according to the third embodiment of the present invention and a combustor using the reheating burner according to the comparative example, and shows a temperature rise in the combustor. The relationship between NOx concentration and NOx is shown.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic configuration of a gas turbine power generator in which a gas turbine combustor according to a first embodiment of the present invention is used. In the figure, a gas turbine GT includes a compressor 1, a combustor 2, and a turbine 3 as main components, and the combustor 2 includes a fuel supply device 5 and a fuel control device 6. Compressed air A supplied from the compressor 1 and fuel F supplied from the fuel supply device 5 via the fuel control device 6 are combusted in the combustor 2, and the high-temperature and high-pressure combustion gas G generated thereby is converted into a turbine. 3 to drive the turbine 3. The compressor 1 is driven by a turbine 3 via a rotating shaft 7, and this turbine 3 also drives a load such as a generator 9 via a speed reducer 8. The combustor 2 includes a can type and an annular type. In the following embodiments, a can type is used. The present invention can also be applied to an annular type.

  As shown in the longitudinal sectional view of FIG. 2, the combustor 2 is a backflow can type in which compressed air A and combustion gas G introduced into the combustor 2 flow in opposite directions in the combustor 2, and has a cylindrical housing. A substantially cylindrical combustion cylinder 10 is accommodated in H, and a combustion chamber 11 is formed therein. A plurality of (for example, six) combustors 2 are arranged on a cylinder concentric with the axis of the rotating shaft 7. The housing H is obtained by connecting a housing top H2 to the head of the housing main body H1 with a bolt 19A, and the end cover 12 is fixed to the head on the distal end side of the housing top H2 by a bolt 12a.

  The combustion cylinder 10 has a head 10a and a peripheral wall 10b connected by a pin (not shown). The inner end portion of the support member 13 made of an annular plate located in the housing H is joined to the tip end portion of the peripheral wall 10b by welding, and the outer end portion of the support member 13 is bolted to the head portion of the housing body H1. It is connected by 19B. Thereby, the combustion cylinder 10 is supported by the housing H via the support member 13. The support member 13 is provided with a plurality of air passage holes 13a arranged in the circumferential direction. An annular air passage 15 is formed between the peripheral wall 10b of the combustion cylinder 10 and the housing main body H1 covering the combustion cylinder 10 to guide the compressed air A from the compressor 1 to the head 10a of the combustion cylinder 10, that is, the upstream side. ing. An air introduction chamber 17 is formed in the housing H on the head side of the end cover 12.

  A burner unit 18 is disposed on the head 10 a of the combustion cylinder 10. This burner unit 18 is a dispersion injection type pilot burner 20 that directly injects fuel F into the combustion chamber 11 and a pre-generated product that is produced by swirling and mixing the fuel F and compressed air A so as to surround the outer periphery of the pilot burner 20. And a premixed main burner 21 that ejects the air-fuel mixture M into the combustion chamber 11.

  In the main burner 21, a premixing passage 26 having an L-shaped longitudinal section is opened radially outward, and a plurality of main fuel nozzles 28 are arranged on the radially outer side of the opened annular air intake 26a. Are arranged at equal intervals in the circumferential direction. A plurality of main fuel injection holes 28 a are formed in a portion of the main fuel nozzle 28 that faces the air intake 27. The base end of the main fuel nozzle 28 is connected to a main fuel introduction port 29 provided in the end cover 12. A plurality of swirlers 27 are arranged in the air intake 27, and the fuel F supplied from the main fuel introduction port 29 is combined with the compressed air A introduced into the air introduction chamber 17 from the air passage 15 and the swirler 27. A swirling force is applied by the above, and after premixing in the premixing passage 26, it is ejected into the combustion chamber 11 as premixed gas M from the annular premixing outlet 26b.

  Fuel F is supplied to the pilot fuel introduction port 22 and the main fuel introduction port 29 from the fuel supply device 5 of FIG.

  One or a plurality of spark plugs 30 are arranged in the upstream portion of the peripheral wall 10 b of the combustion cylinder 10 with the tip thereof facing the combustion chamber 11. The spark plug 30 penetrates the housing H and is fixed to the housing H. At the time of startup, the fuel F is injected from the pilot burner 20 into the combustion chamber 11 and diffusion combustion is performed by ignition by the spark plug 30. Subsequently, during normal operation, the premixed gas M injected from the main burner 21 into the combustion chamber 11 is combusted, and the first combustion region S1 is formed downstream of the main burner 21 in the upstream portion of the combustion cylinder 10. Let it form. Further, on the downstream side of the first combustion region S1 in the combustion cylinder 10, a plurality of (for example, four) through holes 31 penetrating the peripheral wall 10b of the combustion cylinder 10 are provided at equal intervals in the circumferential direction. A premix-type reheating burner 40 is attached to a portion of the housing H that faces each through hole 31, and its tip end faces the combustion chamber 11 through the through hole 31. Thus, the reheating burner 40 is disposed so as to penetrate through the through hole 31 provided on the downstream side of the combustion cylinder 10 with respect to the main burner 21, and the premixed gas M 1 for the reheating burner is injected into the combustion chamber 11. Thus, the second combustion region S2 is formed on the downstream side of the first combustion region S1.

  FIG. 3 shows the details of the chasing burner 40. As shown in FIG. 3A, the reheating burner 40 has a straight burner axis C1 orthogonal to the axis C of the combustion cylinder 10, and includes a body 41 attached to the housing H, A hollow guide tube 42 supported inside the body 41 is provided, and an introduction passage 50 communicating between the body 41 and the guide tube 42 and the internal space of the guide tube 42 is formed. A downstream end (outlet) 42 b of the guide cylinder 42 passes through the through hole 31 of the combustion cylinder 10 and faces the combustion chamber 11.

  The introduction passage 50 introduces a part of the compressed air A guided in the air passage 15 toward the head portion 10 a (FIG. 1) of the combustion cylinder 10 toward the outside in the radial direction of the combustion cylinder 10, and then in the radial direction. It is formed as a 180 ° folding passage that is folded inward and supplied to the combustion chamber 11 inside the combustion cylinder 10. The body 41 has a fuel nozzle 43 and a cap 44 that covers the upper portion thereof. The fuel nozzle 43 has a nozzle body 43a and a nozzle cover 43b fitted on the outer periphery thereof, and a fuel reservoir 45 is formed between the nozzle body 43a and the nozzle cover 43b. A nipple 48 that forms a fuel introduction path 47 for introducing fuel F into the nozzle cover 43b is attached to at least one location of the nozzle cover 43b. As shown in FIG. 3B, the nozzle body 43a is provided with a plurality of (for example, 16) fuel supply holes 49 at equal intervals around the burner axis C1, and the fuel injection direction is the burner axis. Directed to C1. The fuel nozzle 43 supplies the fuel F to the introduction passage 50 from the fuel supply hole 49, and generates a premixed gas M <b> 1 by mixing with the compressed air A in the introduction passage 50. A mount 46 is fixed to the housing H by welding or the like, and a fuel nozzle 43 and a cap 44 that form the body 41 are attached to the mount 46 by fastening members 52 such as bolts.

  The introduction passage 50 as the return passage includes a first passage portion 50a that protrudes radially outward from the housing H, and a second passage portion 50b that turns back from the first passage portion 50a and enters the combustion cylinder 10. And the folded portion 50c is located between the end of the first passage portion 50a and the start end of the second passage portion 50b. Therefore, the compressed air A flowing in from the first passage portion 50a is deflected by 180 ° at the folded portion 50c, then flows into the second passage portion 50b, and is introduced into the combustion chamber 11 in the combustion cylinder 10 from the second passage portion 50b. The The compressed air A is greatly disturbed when folded at the folded portion 50c. Thus, in combination with the fuel F being dispersed from the plurality of fuel supply holes 49 and supplied into the introduction passage 50, the stirring of the fuel F and the compressed air A is promoted. In addition, since the introduction passage 50 is a turn-back passage, the premixing distance between the compressed air A and the fuel F is also increased, so that the stirring of the compressed air A and the fuel F is further promoted. As a result, a premixed gas M1 with little fuel F concentration unevenness is obtained.

  As shown in FIG. 4 (A), the guide cylinder 42 and the cap 44, which are constituent members of the introduction passage 50, are arranged so that their axial centers coincide with the burner axis C1, and are shown in FIG. 4 (B). The guide cylinder 42 is supported by the cap 44 via a plurality of stays 53. That is, the stay 53 is inserted into the insertion hole 54 provided in the cap 44 shown in FIG. 4A and fixed by welding, and the lower portion of the stay 53 is fitted into the groove 42a in the upper portion of the guide tube 42 and fixed by welding. . The guide cylinder 42 and the cap 44 assembled in this way are placed on the mount 46 together with the fuel nozzle 43 shown in FIG. 3A, and the fastening member 52 such as a bolt is connected to the bolt insertion hole 56 of the cap 44. And it is fixed to the housing H by being inserted into the bolt insertion hole 57 of the fuel nozzle 43 and screwed into the screw hole 58 of the mount 46. Thus, the assembly of the body 41 is facilitated by previously assembling the guide tube 42 and the cap 44.

  Between the outlet 42 b of the guide cylinder 42 and the through hole 31 of the combustion cylinder 10, a ring-shaped seal member 60 that closes the gap between the outer periphery of the combustion cylinder 10 and the inner periphery of the through hole 31 is provided. By providing this seal member 60, the compressed air A is prevented from entering the combustion cylinder 10 through the gap between the outer periphery of the combustion cylinder 10 and the inner periphery of the through hole 31. The seal member 60 includes a seal receiving portion 61 fixed to the combustion cylinder 10 and a donut plate-like seal piece 62 fixed to the guide cylinder 42, and the inside of the seal space 63 formed in the seal receiving portion 61. A seal piece 62 is fitted into the guide cylinder 42 to seal between the guide cylinder 42 and the through hole 31 of the combustion cylinder 10. The seal piece 62 is set so as to be movable in the radial direction orthogonal to the burner axis C1 in the seal space 63, and thereby absorbs assembly errors and thermal expansion differences between the housing H and the combustion cylinder 10.

  Next, the operation of the gas turbine combustor according to the above configuration will be described with reference to FIG. In the case of the diffusion operation (non-low NOx operation) at the time of starting the combustor 2 and after the start-up, the pilot burner 20 is operated and the fuel F introduced from the fuel introduction port 22 is injected into the combustion chamber 11 to perform diffusion combustion. Let During normal operation (during low NOx operation), the main burner 21 is operated, and the premixed gas M generated in the main burner 21 is injected into the combustion chamber 11 for lean combustion in the first combustion region S1. . Thereby, the combustion temperature in the combustion chamber 11 falls, and generation | occurrence | production of NOx is suppressed.

  Further, the second combustion, in which the premixed gas M1, which is injected into the combustion chamber 11 from the downstream burner 40 and has a small concentration variation in the fuel F, is considerably heated by the first combustion region S1. It is introduced into the region S2 and burned in the second combustion region S2. Thereby, generation | occurrence | production of NOx can be reduced at a combustor exit and NOx emission amount can be suppressed.

  Here, the reheating burner 40 is disposed on the downstream side of the main burner 21 of the head portion 10a of the combustion cylinder 10 and is a part of the compressed air A introduced from the existing air passage 15 into the introduction passage 50 of the reheating burner 40. Since the premixed gas M1 is generated by supplying the fuel F to the section, the conventional large-scale premixing duct becomes unnecessary, and the reheating burner 40 becomes compact. Compactness can be achieved. Further, since the compressed air A is guided inward in the radial direction toward the inside of the combustion cylinder 10 by the introduction passage 50, a penetrating force directed inward in the radial direction of the combustion cylinder 10 is applied. Thereby, it is prevented that the reheating burner 40 is damaged by backfire in the introduction passage 50.

  FIG. 5 shows a reheating burner 40A according to a second embodiment of the present invention. In the second embodiment, the same or corresponding parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof is omitted, and only different configurations will be mainly described. In the second embodiment, among the first passage portion 50Aa that forms the introduction passage 50A that is a return passage and the second passage portion 50Ab that is turned back from the first passage portion 50Aa, the intermediate portion of the first passage portion 50Aa is provided. A throttle part 51b having a passage area smaller than the upstream part 51a on the upstream side is provided, and an enlarged part 51c having a passage area larger than the throttle part 51b is provided downstream of the first passage part 50Aa. ing. The end portion of the first passage portion 50Aa, that is, the end portion of the enlarged portion 51c and the start end of the second passage portion 50Ab is a folded portion 50Ac. The fuel supply hole 49 is disposed facing the throttle portion 51b where the static pressure of the compressed air A decreases. Accordingly, the fuel F can be smoothly supplied from the fuel supply hole 49 to the first passage portion 50Aa.

  Thus, the first passage portion 50Aa has a large passage area at the upstream portion 51a and the enlarged portion 51c at the downstream portion, and the narrowest passage area at the narrowed portion 51b at the intermediate portion. In this case, of the mount 46, the body 41, and the guide tube 42 that form the first passage portion 50Aa, the portion of the mount 46 and the body 41 that faces the first passage portion 50Aa is a flat surface. A bulging portion 65 is formed on the outer peripheral surface, and the outer diameter Do is small at the portion facing the upstream portion 51a of the first passage portion 50Aa and from the upstream side at the portion facing the throttle portion 51b of the first passage portion 50Aa. It is set so that it gradually increases toward the downstream side and then remains constant and further decreases at the portion facing the enlarged portion 51c of the first passage portion 50Aa.

  In the second embodiment, when a part of the compressed air A in the air passage 15 flows in the radially outward direction of the combustion cylinder 10 from the upstream portion 51a of the first passage portion 50Aa, it passes through the throttle portion 51b in the intermediate portion. When the flow rate increases, the flow rate decreases and the static pressure increases when the flow reaches the enlarged portion 51c. This pressure change causes a large disturbance in the compressed air A. The compressed air A is further disturbed by folding at the folded portion 50Ac. Due to such disturbance, the compressed air A and the fuel F are well agitated, and premixing is promoted. Other operations and actions are the same as those in the first embodiment.

  FIG. 6 shows the concentration distribution of the premixed gas M2 at the outlet of the reheating burner 40A, that is, the outlet 42b of the guide cylinder 42. The first area P 1 with the highest density (maximum density 0.024) is only the narrow part of the central part, and the third area P3 (density 0.015) with the lowest density accounts for about 40%, and the second area P with intermediate density. 2 occupies the remainder, and there is little variation in fuel concentration as a whole. As described above, in the second embodiment, the maximum peak concentration of the fuel F is almost halved and the concentration distribution is smoothed as compared with the reheating burner 100 according to a comparative example (FIGS. 10 and 11) described later. Thus, it can be seen that a uniform premixed gas M2 with less fuel F concentration unevenness is generated.

  FIG. 7 shows a reheating burner 40B according to a third embodiment of the present invention. As in the second embodiment, the third embodiment includes a first passage portion 50Ba that forms an introduction passage 50B as a return passage, and a second passage portion 50Bb that is turned back from the first passage portion 50Ba. A narrowed portion 52b having a small passage area and an enlarged portion 52c downstream thereof are provided at an intermediate portion of the one passage portion 50Ba. The fuel supply hole 49 for ejecting the fuel F to the first passage portion 50Ba is arranged in the fuel nozzle 43 so as to face the throttle portion 52b. A folded portion 50Bc is formed between the terminal end of the first passage portion 50Ba and the start end of the second passage portion 50Bb.

  In the case of the third embodiment, unlike the second embodiment, the outer peripheral surface of the guide tube 42 is a flat surface, but the inner surface (inner diameter side) of the inner peripheral surface of the body 41 facing the first passage portion 50Ba. ) And the inner diameter Di gradually decreases from the portion facing the upstream portion 52a of the first passage portion 50Ba to the portion facing the throttle portion 52b downstream thereof. It is set to be constant and further gradually increased in the portion facing the enlarged portion 52c in the downstream portion of the first passage portion 50Ba. The bulging portion 66 is formed in the fuel nozzle 43 of the body 41, and its upstream end portion (lower end portion in FIG. 7) extends upstream to cover a part of the inner peripheral surface of the body 41. .

  Also in the third embodiment, as in the second embodiment, the pressure of the compressed air A is reduced at the throttle portion 52b. Therefore, the fuel F from the fuel supply hole 49 disposed facing the throttle portion 52b is supplied to the first embodiment. The passage portion 50Ba can be supplied smoothly. In addition, since the compressed air A increases in flow rate at the throttle portion 51b and then decreases in flow velocity at the enlarged portion 51c and increases in static pressure, a large turbulence occurs at the enlarged portion 51c, and a turbulence occurs at the folded portion 50Bc. The compressed air A and the fuel F are well agitated to promote premixing, and a uniform premixed gas M3 with little concentration unevenness is obtained. Other operations and effects are substantially the same as those in the above embodiments.

  As shown in FIG. 8, the concentration distribution of the premixed gas M3 at the outlet of the reheating burner 40B, that is, the outlet 42b of the guide cylinder 42 is centered on the first area P1 (maximum concentration 0.023) having the highest concentration. The second area P2 (concentration 0.020) having a slightly lower concentration than that of the second area P2 occupies the remaining portion, and the fuel concentration variation is extremely small as a whole. As described above, also in the third embodiment, the maximum peak concentration of the fuel F is drastically reduced to 1/3 or less, and the concentration distribution is also smooth, as compared with the burn-up burner 100 (FIGS. 10 and 11) of the comparative example described later. It can be seen that a premixed gas M3 with very little concentration variation in the fuel F is generated.

  FIG. 9A shows a reheating burner 40C according to the fourth embodiment of the present invention. As shown in the figure, the reheating burner 40C has a straight burner axis C1 orthogonal to the axis C of the combustion cylinder 10, and has a fuel nozzle 70 attached to the housing H and a diameter of the combustion cylinder 10. A guide tube 73 extending inward in the direction and an annular inflow port 74 formed between the guide tube 73 and the fuel nozzle 70 are arranged concentrically with the guide tube 73 and into the guide tube 73. A plurality of guide pieces 75 for allowing the compressed air A to flow in, and a cylindrical deflecting cylinder 76 disposed so as to cover the outer periphery of the inflow port 74 with a gap B1 between the inflow port 74. . An upstream portion of the introduction passage 50 </ b> C is formed by the inflow space 74 and the inner space of the guide cylinder 73 between the deflection cylinder 76 and the guide piece 75.

  The fuel nozzle 70 includes a columnar nozzle body 71 with a collar that is attached to a mount 46 provided in the housing H by a fastening member 52 such as a bolt, and a disk-shaped nozzle plate 72 fixed to the nozzle body. A fuel reservoir space 78 is formed between the fuel nozzle 70 and the nozzle plate 72. The nozzle body 71 and the nozzle plate 72 are disposed concentrically on the burner axis C1.

  Further, the nozzle body 71 is formed with a fuel introduction path 81 for introducing the fuel F into the fuel reservoir space 78, and a nipple 83 that forms a fuel introduction port 82 of the fuel introduction path 81 is attached. A fuel supply hole 85 communicating with the fuel reservoir space 78 is formed in the outer peripheral portion of the nozzle plate 72. The tracking burner 40C further includes an introduction cylinder 79 that is attached to the through hole 31 of the combustion cylinder 10 and forms the downstream portion of the introduction passage 50C. The inlet 79a of the introduction tube 79 is curved in the outer diameter direction like a bell mouth. As the introduction cylinder 79, the existing combustion cylinder 10 can be used as it is. A gap B2 in the axial direction is provided between the guide cylinder 73 and the introduction cylinder 79, so that even if the shape dimensions, assembly and mounting position accuracy of the guide cylinder 73 and the introduction cylinder 79 are low, both 73, The contact of 79 is prevented, and manufacturability and assemblability are improved.

  As shown in FIG. 9B, the guide pieces 75 are arranged concentrically with the nozzle plate 72 and are provided in plural numbers (for example, 12 pieces) at equal intervals in the circumferential direction, and cover the upper part of the guide pieces 75. The fuel supply holes 85 of the nozzle plate 72 are provided one by one between the adjacent guide pieces 75.

  The compressed air A from the air passage 15 shown in FIG. 9A flows in from the gap B1 between the deflection cylinder 76 and the guide piece 75, but when entering the inlet 74, the compressed air A is partitioned by the adjacent guide piece 75. It flows from the plurality of divided openings 75 a and is introduced toward the center of the inflow port 74. The airflows a1 flowing in from the respective division openings 75a are deflected 90 ° downward by the central projections 72a in a state where it is avoided that the flow velocity is reduced by directly colliding with each other by the central projections 72a. It passes through the space, flows inward in the radial direction of the combustion cylinder 10, and is introduced into the combustion chamber 11 inside the combustion cylinder 10 from the outlet 79 b of the introduction cylinder 79.

  In the fourth embodiment, the first passage portion 50Ca is formed by the gap B1 between the deflection cylinder 76 and the guide piece 75, and the second passage portion 50Cb is formed by the inner space of the guide cylinder 73 and the introduction cylinder 79. The folded portion 50Cc is formed by the portion where the guide piece 75 is provided. Therefore, the compressed air A that has flowed from the air passage 15 into the first passage portion 50Ca between the deflection cylinder 76 and the guide piece 75 flows in the first passage portion 50Ca outward in the radial direction of the combustion cylinder 10, When it flows through the guide piece 75 and flows into the inner space of the guide cylinder 73, it is deflected so that it is folded back by 180 °. Since the fuel F ejected from the fuel supply hole 85 of the nozzle plate 72 is supplied to the compressed air A, both are well agitated in the introduction passage 50C to promote premixing, and uniform premixing with little concentration unevenness. Qi M4 is obtained.

  Furthermore, in the case of the fourth embodiment, since the introduction passage 50C does not protrude outward in the radial direction of the housing H, the combustor 2 can be made more compact than the first to third embodiments. . Since other operations and actions are substantially the same as those of the above-described embodiments, detailed description thereof will be omitted.

  The tracking burner 100 of the comparative example will be described with reference to FIG. A reheating burner 100 shown in FIG. 10A has a straight burner axis C1 orthogonal to the axis C of the combustion cylinder 10, has a fuel inlet 102 at the upper end, and a fuel supply hole 101a at the lower end. The formed straight fuel nozzle 101 is fixedly attached to the housing H with a fastening member 105 such as a bolt, and is arranged so that the fuel supply hole 101a faces the introduction cylinder 103 attached to the through hole 31 of the combustion cylinder 10. It is what. The introduction tube 103 has a bell mouth-shaped inlet 103a. As shown in FIG. 10B, eight fuel supply holes 101a are provided at equal intervals in the circumferential direction of the fuel nozzle 101. In the case of the reheating burner 100, the compressed air A from the air passage 15 is deflected by 90 ° and introduced into the introduction cylinder 103, and the fuel F ejected from the fuel supply hole 101a and the pre-injection are injected into the introduction cylinder 103. Mixed. Thus, in the case of the comparative example, when it flows into the introduction cylinder 103, it is only deflected by 90 ° instead of 180 °, so that the compressed air A is not sufficiently disturbed, and the fuel Since the position where F is supplied is after the compressed air A is deflected, the fuel F and the compressed air A are not sufficiently stirred. Further, the premixing distance is about the height dimension of the introduction cylinder 103, which is significantly shorter than those of the above embodiments. Therefore, the fuel F and the compressed air A are not sufficiently agitated, and only the premixed gas M5 with insufficient premixing and high concentration unevenness of the fuel F is obtained.

  As shown in FIG. 11, the concentration distribution of the fuel at the outlet of the burner 100 according to the comparative example, that is, the outlet 103b of the introduction tube 103 is the first area P1 (maximum concentration 0.074) having the highest concentration in the central portion. The third area P3 (density 0.000) having the lowest density spreads over the entire outer peripheral portion, and the second area P2 showing intermediate density slightly exists between the first area P1 and the third area P3. ing. As is clear from this, in the comparative example, the premixing is insufficient and the fuel concentration unevenness of the premixed gas M5 is extremely large.

  FIG. 12 shows the results of a combustion experiment between the combustor 2 using the reheating burner 40A of the third embodiment (FIG. 7) and the combustor using the reheating burner 100 of the comparative example shown in FIG. Show. The horizontal axis of FIG. 12 shows the temperature of the combustion gas G at the outlet 10e of the combustion cylinder 10 shown in FIG. 2, and the vertical axis shows the NOx concentration. As shown in FIG. 12, in the case of this comparative example, when the temperature rise in the combustor increases and approaches the evaluation reference temperature Tr corresponding to the load factor of 100%, the NOx concentration increases significantly. On the other hand, in the case of the third embodiment, it is understood that the NOx concentration is low and the NOx emission amount is suppressed even when the temperature falls below the NOx target value in all temperature regions and reaches the reference temperature Tr. . In the first, second, and fourth embodiments, almost the same tendency as in FIG. 12 was observed.

  Note that the Mayburner 21 is not limited to the premixed burner used in the above embodiment, and a diffusion burner may be used.

  As described above, the preferred embodiments have been described with reference to the drawings. However, those skilled in the art will readily understand various changes and modifications within the obvious scope by looking at the present specification. Accordingly, such changes and modifications are to be construed as within the scope of the invention as defined by the appended claims.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Combustor 3 Turbine 5 Fuel supply apparatus 6 Fuel control apparatus 10 Combustion cylinder 10a Circumferential wall 10b Head 11 Combustion chamber 15 Air passage 21 Main burner 40, 40A, 40B, 40C Reheating burner 41 Body 42 Guide cylinder 43 Fuel Nozzle 49 Fuel supply hole 50, 50A, 50B, 50C Introducing passage 50a, 50Aa, 50Ba First passage portion 50b, 50Ab, 50Bb Second passage portion 50c, 50Ac, 50Bc Folded portion 51a, 52a Upstream portion 51b of the first passage portion , 52b Restriction part 51c of the first passage part 51c, 52c Enlarged part of the first passage part 60 Seal member 65 Swelling part 73 Guide cylinder 75 Guide piece 76 Deflection cylinder 79 Introduction cylinder A Compressed air F Fuel H Housing S1 First combustion Region S2 Second combustion region

Claims (7)

A combustor that combusts compressed air and fuel supplied from a compressor and supplies the fuel to a turbine.
A main burner provided at the head of the combustion cylinder forming the combustion chamber, and a reheating burner disposed through the peripheral wall of the combustion cylinder on the downstream side of the combustion cylinder with respect to the main burner,
The memorial burner is
An introduction passage for introducing a part of the compressed air into the combustion cylinder from an air passage formed between the combustion cylinder and a housing covering the combustion cylinder;
A fuel nozzle that supplies fuel from a fuel supply hole to compressed air introduced into the introduction passage to generate a premixed gas in the introduction passage;
The introduction passage is a gas turbine combustor which is a turn-back passage that introduces compressed air in the air passage to the outside in the radial direction of the combustion cylinder, and then turns back toward the inside in the radial direction to supply the inward of the combustion cylinder.   2. The gas turbine according to claim 1, wherein the introduction passage includes a first passage portion that protrudes radially outward from the housing, and a second passage portion that turns back from the first passage portion and enters the combustion cylinder. Combustor.   3. The chasing burner according to claim 2, wherein the chasing burner has a body attached to the housing and a guide cylinder supported inside the body, and the first passage portion is between the body and the guide cylinder. A gas turbine combustor which is formed and a part of the second passage portion is formed inside the guide tube.   The gas turbine according to claim 1, 2, or 3, wherein the introduction passage is formed with a throttle portion having a passage area smaller than an upstream side thereof, and subsequently an enlarged portion having a passage area larger than the throttle portion. Combustor.   In Claim 2 or 3, a throttle part having a smaller passage area than the upstream side thereof and an enlarged part having a larger passage area than that of the throttle part are formed in the first passage part, and fuel is supplied to the first passage part. A gas turbine combustor in which a fuel supply hole ejected to one passage portion is disposed facing the throttle portion.   The seal member for closing a gap between the outer periphery of the combustion tube and the inner periphery of the through hole is provided between the downstream end portion of the guide tube and the through hole of the combustion tube through which the downstream portion passes. Gas turbine combustor.   2. The chasing burner according to claim 1, wherein the chasing burner includes a body attached to the housing, a guide cylinder extending radially inward of the combustion cylinder, and an annular shape formed between the guide cylinder and the body. A plurality of guide pieces arranged concentrically with the guide cylinder at the inlet and allowing compressed air to flow into the guide cylinder, and arranged so as to cover the outer periphery of the inlet with a gap between the inlet and the inlet A gas turbine combustor including a deflecting cylinder, wherein the introduction passage is formed by an inflow space between the deflection cylinder and the guide piece, and an inner space of the guide cylinder.

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