JP2009024631A - Gas turbine facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas turbine facility having an economical exhaust diffuser capable of preventing generation of crack due to thermal deformation by approximating thermal capacities of flanges and cylindrical bodies. <P>SOLUTION: In this invention, the exhaust diffuser 5 is structured by separating the cylindrical bodies 14N, 15N, 16N, 14S, 15S, 16S into a plurality of sections in an exhaust gas flow-out direction, forming the flanges 15Fs, 16Fs, 15Fn, 16Fs at separated parts of the cylindrical bodies and inserting bolts 19 to the flanges and fastening them with nuts 20. In the exhaust diffuser 5, the wall thickness of the flanges is formed to be as thin as that of the cylindrical bodies and washers 18, 20, 21 thicker than the wall thickness of the flanges are brought into face contact with the fastening part of the flange of the adjacent cylindrical body in a surface-to-surface manner by using the bolts and the nuts. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gas turbine facility, and more particularly to a gas turbine facility in which an exhaust diffuser that guides exhaust gas discharged from a gas turbine to a flue is divided into three in the exhaust gas outflow direction.

  In general, gas turbine equipment is equipped with an exhaust diffuser on the exhaust gas outlet side of the gas turbine in order to guide the exhaust gas discharged from the gas turbine to the flue. Is divided into three in the exhaust gas outflow direction, and the divided portions are flange-coupled.

  As a related technique, there is a technique disclosed in Patent Document 1.

JP 2000-303857 A

  In general, the exhaust diffuser having a three-part configuration in the background art described above has a thicker flange than the cylindrical body in order to secure a fastening force by a bolt and a nut. However, by making the thickness of the flange thicker than that of the cylinder, the heat capacity of the cylinder and the flange is different, and as a result, the thermal expansion of the cylinder and the flange is different due to the high-temperature exhaust gas that circulates inside. As a result, thermal deformation occurs near the boundary between the cylinder and the cylinder, causing cracks in the cylinder and causing exhaust gas to leak out of the exhaust diffuser.

  On the other hand, in order to make the heat capacity of the cylinder and the flange of the exhaust diffuser equal, it is conceivable that the thickness of the flange is made thin according to the cylinder. However, when the thickness is the same as that of the cylindrical body, the fastening force cannot be secured at the flange coupling portion, and the flange is likely to be wavy and deformed due to thermal elongation, causing exhaust gas leakage.

  On the other hand, it is also considered that the thickness of the cylindrical body is increased by combining the flanges, but this is not preferable because it is uneconomical in consideration of the overall material cost.

  An object of the present invention is to provide a gas turbine facility having an economical exhaust diffuser that can prevent cracks due to thermal deformation by approximating the heat capacities of a flange and a cylinder.

  In order to achieve the above object, the present invention has a configuration in which the cylinder of the exhaust diffuser is divided into three parts in the exhaust gas outflow direction, a flange is formed in the divided part of the cylinder, and a bolt is passed through the flange and fastened with a nut. In the exhaust diffuser, the thickness of the flange is formed to be as thin as the cylindrical body, and a washer that is thicker than the thickness of the flange is brought into surface contact with the fastening portion of the adjacent flange and fastened with a bolt and a nut. It is.

  By comprising in this way, the heat capacity of a cylinder and a flange can be approximated, As a result, generation | occurrence | production of a crack can be prevented by suppressing the thermal deformation by a thermal expansion difference. Moreover, by making the flange have a thick washer in surface contact and fastening, the deformation of the flange due to thermal elongation can be suppressed, and exhaust gas leakage can be prevented. Furthermore, since the flange can be made thin, the material cost becomes economical.

  Therefore, according to the present invention, it is possible to obtain a gas turbine facility having an economical exhaust diffuser that can prevent cracks due to thermal deformation by approximating the heat capacities of the flange and the cylinder.

  Hereinafter, an embodiment of a gas turbine facility according to the present invention will be described with reference to FIGS.

  In general, the gas turbine equipment 1 mixes an air compressor 2 that compresses and discharges air, and compressed air discharged from the air compressor 2 and fuel supplied by a fuel supply means (not shown). An exhaust diffuser comprising a combustor 3 to be combusted, a gas turbine 4 driven by the combustion gas combusted in the combustor 3, and a cylindrical body connected to the gas turbine 4 to guide exhaust gas discharged to a flue And 5.

  The air compressor 2 and the gas turbine 4 have a common rotating shaft 6. The air compressor 2 has a moving blade 7 fixed to the rotary shaft 6 in multiple stages in the axial direction, and a stationary blade 8 positioned between the moving blades 7. The stationary blade 8 is supported by the compressor casing 9. The gas turbine 4 includes a moving blade 10 that is fixed to the rotating shaft 6 in multiple stages in the axial direction, and a stationary blade 11 that is positioned between the moving blades 10. The stationary blade 11 is supported by the turbine casing 12.

  On the other hand, a plurality of combustors 3 are installed in a ring shape around the rotating shaft 6 in a casing 12E extending from the turbine casing 12 to the air compressor 2, and on the combustion gas discharge side of each combustor 3 Each transition piece 13 is connected, and the combustion gas outlet of the transition piece 13 opens to the first stage side of the stationary blade 11 of the gas turbine 4.

  An exhaust diffuser 5 that guides the exhaust gas to the flue is connected to the exhaust gas discharge side of the turbine casing 12. This exhaust diffuser 5 is divided into an upstream diffuser 14, an intermediate diffuser 15, and a downstream diffuser 16 in the exhaust gas outflow direction, and the cylinders constituting each of the diffusers 14 to 16 are concentric with the inner cylinder 14N. , 15N, 16N and outer cylinders 14S, 15S, 16S.

  These are covered by a gas turbine compartment 17.

  In the above configuration, a part of the compressed air a compressed by the air compressor 2 is supplied into the combustor 3 in the casing 12E, mixed with the fuel supplied by the fuel supply means, and burned. The high-temperature and high-pressure combustion gas H combusted in the combustor 3 is rectified by the stationary blade 11 via the transition piece 13 and injected to the moving blade 10 to drive the rotating shaft 6. Although not shown in the figure, a generator is connected to the rotating shaft 6, and the generator is rotated to generate power.

  The above-described configuration is the same as that of the conventional gas turbine equipment, but in the present embodiment, the intermediate diffuser 15 of the exhaust diffuser 5 and the adjacent inner cylinders 15N and 16N of the downstream diffuser 16 and the adjacent outer cylinders 15S and 16S. This connection structure is configured as shown in FIGS.

  In other words, the connection structure between the adjacent outer cylinders 15S and 16S of the intermediate diffuser 15 and the downstream diffuser 16 will be described as an example. The wall thickness t of the outer cylinders 15S and 16S is the minimum necessary to withstand the high-temperature and high-pressure combustion gas H. The flanges 15Fs and 16Fs formed at the connecting portions of the outer cylinders 15S and 16S are also formed to have the same thickness t as the thickness t of the outer cylinders 15S and 16S.

  Then, in order to compensate for a decrease in strength due to a decrease in the thickness of the flanges 15Fs and 16Fs, a rectangular washer 18 having a thickness Tc is brought into surface contact around the bolt through holes 15H and 16H of the flanges 15Fs and 16Fs. In this state, the bolts 19 are passed through the bolt holes 18H of the washers 18 and the bolt through holes 15H and 16H of the flanges 15Fs and 16Fs, and the nuts 20 are screwed into the through ends and fastened.

  By the way, the original thickness of the flanges 15Fs and 16Fs is usually set to three times or more the thickness t of the outer cylinders 15S and 16S in order to secure the fastening force. Therefore, when the outer cylinders 15S and 16S have a thickness t of 8 mm, an apparent flange having a total thickness of 24 mm is formed around the bolt through holes 15H and 16H by setting the thickness Tc of the washer 18 to 16 mm. The total thickness Tf of the adjacent apparent flanges is 48 mm.

  Since the washer 18 is in surface contact with the surfaces of the flanges 15Fs and 16Fs, stress is not concentrated on a part of the washer 18 during fastening, and the flanges 15Fs and 16Fs are sandwiched by the entire surface of the washer 18. As a result, thermal cycle fatigue damage due to stress concentration can be prevented from occurring in the flanges 15Fs and 16Fs. Therefore, it is outside the scope of the present invention to form a protrusion that concentrates stress on the face of the washer 18 facing the flanges 15Fs, 16Fs.

  By configuring in this way, the thicknesses t of the outer cylinders 15S, 16S and the flanges 15Fs, 16Fs become equal, so that there is no bias in heat capacity, thereby eliminating the thermal expansion difference due to high-temperature exhaust gas and thermal stress. Can be suppressed. As a result, generation of cracks due to thermal stress can be prevented. Further, by making the heat capacity uniform, thermal deformation that narrows the gap between the outer diameter Cb of the bolt 19 and the diameter Cf of the bolt through holes 15H and 16H due to the exhaust gas temperature can be reduced, so the diameter of the bolt through holes 15H and 16H can be reduced. It is also possible to prevent breakage of the bolt 19 that has occurred due to the deformation of Cf and contact with the bolt 19.

  Furthermore, since the apparent thickness t + Tc can be secured even if the flanges 15Fs and 16Fs themselves are thinned, the fastening force by the bolt 19 and the nut 20 can be secured, and deformation of the flanges 15Fs and 16Fs can be prevented. Can do.

  The flange 15Fs, 16Fs and the washer 18 having the same thickness as the inner cylinders 15N, 16N are formed on the inner cylinders 15N, 16N side, and the washer 18 is applied to achieve the same effect. be able to.

  By the way, the washer 18 has a square shape. If the corners are in contact with the outer cylinders 15S, 16S and the inner cylinders 15N, 16N, the washer 18 will not rotate when the nut 20 is screwed. In addition, the through hole of the washer 18 can be substantially matched with the bolt through holes 15H and 16H of the flanges 15Fs and 16Fs, and the washer 18 can be prevented from hitting the bolt 19 and the chance of breakage of the bolt can be reduced. it can. However, it is desirable that the washer 18 be fixed by welding so that it does not shift from the bolt through holes 15H and 16H. When the corner of the washer 18 is disliked from contact with the outer cylinders 15S, 16S and the inner cylinders 15N, 16N, the corner is formed by fixing the washer 18 to the flanges 15Fs, 16Fs, 15Fn, 16Fn by welding. Since the outer cylinders 15S and 16S and the inner cylinders 15N and 16N are not in contact with each other, the thermal stress generated in the outer cylinders 15S and 16S and the inner cylinders 15N and 16N is transmitted to the bolt 19 via the washer 18 and broken. There is no fear.

  5 to 7 show a second embodiment according to the present invention. The same reference numerals as those in FIGS. 1 to 4 denote the same components, and thus detailed description thereof is omitted.

  In the present embodiment, a configuration different from the first embodiment is a configuration of a washer. That is, the washer 22 in the present embodiment forms an engaging portion 21F that engages with the outer periphery of the flanges 15Fs, 16Fs, 15Fn, and 16Fn of the outer cylinders 15S and 16S and the inner cylinders 15N and 16N. 21H is prevented from shifting from the bolt through holes 15H and 16H of the flanges 15Fs, 16Fs, 15Fn and 16Fn. As a matter of course, the thickness Tc of the washer 22 first has the same thickness as that of the embodiment.

  By using such a washer 22, rotation of the washer 22 is prevented when the bolt 19 and the nut 20 are tightened. Therefore, it is not necessary to fix the flange 15Fs, 16Fs, 15Fn, 16Fn by welding, and the washer 22 Can be prevented from shifting from the bolt through holes 15H, 16H of the flanges 15Fs, 16Fs, 15Fn, 16Fn. As a result, it is possible to reduce the chance of the flanges 15Fs, 16Fs, 15Fn, 16Fn and the washer 22 coming into contact with the bolts 19 due to the deviation between the bolt holes and the bolt through holes 15H, 16H, and the bolts 19 may be broken even when subjected to thermal stress. Can prevent force.

  In addition, since there is no bias in heat capacity, there is no difference in thermal expansion due to high-temperature exhaust gas, and the generation of thermal stress can be suppressed, and cracks generated in the outer cylinders 15S, 16S and inner cylinders 15N, 16N due to thermal stress can be prevented. In addition, by making the heat capacity uniform, it is also possible to reduce thermal deformation that narrows the gap between the outer diameter Cb of the bolt 19 and the diameter Cf of the bolt through holes 15H and 16H due to the exhaust gas temperature. It is possible to prevent the breakage of the bolt 19 caused by the deformation of the diameters Cf of 15H and 16H and contact with the bolt 19, and the apparent thickness even if the thickness of the flanges 15Fs and 16Fs itself is reduced. Since the length t + Tc can be secured, the fastening force by the bolt 19 and the nut 20 can be secured, and the flanges 15Fs and 16Fs are prevented from being deformed. That can bets are the same as the above embodiment.

  8 to 10 show a third embodiment according to the present invention. The same reference numerals as those in FIGS. 1 to 4 denote the same components, and thus detailed description thereof is omitted.

  Also in the present embodiment, a structure different from the first embodiment is a washer structure. That is, the washer 22 in the present embodiment is formed in a cylindrical shape having the same thickness Tc as in the first embodiment.

  By using such a washer 22, as in the first embodiment, there is no bias in heat capacity, thereby preventing cracks generated in the outer cylinders 15S, 16S and the inner cylinders 15N, 16N due to thermal stress. It is possible to prevent breakage of the bolt 19 in the bolt hole 22H and the bolt through holes 15H and 16H, and to secure the fastening force by the bolt 19 and the nut 20 even if the flanges 15Fs and 16Fs themselves are thin.

  However, in this embodiment, when the bolt 19 and the nut 20 are fastened, the cylindrical washer 22 is easier to rotate than the washer of each of the above embodiments. Since there is no interference with 15S, 16S and the inner cylinders 15N, 16N, it is advantageous in terms of protecting the outer cylinders 15S, 16S and the inner cylinders 15N, 16N. However, in the case where the washer 22 is disliked when the bolt 19 and the nut 20 are fastened, it does not prevent the cylindrical washer 22 from being welded to the outer cylinders 15S and 16S and the inner cylinders 15N and 16N.

  FIGS. 11 to 13 show a fourth embodiment according to the present invention. The same reference numerals as those in FIGS. 1 to 4 denote the same components, and thus detailed description thereof is omitted.

  In the present embodiment, the washer 18 in the first embodiment shown in FIG. 1 to FIG. 4 is applied, and further over the bolt through holes 15H and 16H of the flanges 15Fs and 16Fs and the bolt hole 18H of the washer 18. The bolt protection sleeve 23 is attached. The bolt protection sleeve 23 is preferably formed to have a thickness equal to the gap between the inner diameter Cf of the bolt through holes 15H and 16H and the outer diameter Cb of the bolt 19.

  By adopting the above configuration, in addition to the effects obtained by increasing the thickness of the washer 15 and flanges 15Fs and 16Fs of the first embodiment, the following effects can be achieved. That is, even if the flanges 15Fs and 16Fs are thermally deformed due to the exhaust gas temperature and try to press the bolt 19, the bolt protective sleeve 23 exists on the outer diameter Cb side of the bolt 19, so that the pressing force is the bolt protective sleeve. 23, and therefore, a force that causes breakage does not act on the bolt 19. By using a soft material such as copper or aluminum as the material of the bolt protection sleeve 23, the stress due to thermal deformation of the flanges 15Fs and 16Fs can be absorbed by the deformation of the bolt protection sleeve 23. As a result, the bolt 19 Of course, the damage to the flanges 15Fs and 16Fs can be prevented by firmly preventing thermal deformation.

  Incidentally, the present embodiment is applied to the first embodiment, but it is needless to say that the present embodiment can also be applied to the second and third embodiments.

  Furthermore, in each embodiment, only the fastening portion between the intermediate diffuser 15 and the downstream diffuser 16 has been described. On the other hand, the fastening portion between the upstream diffuser 14 and the intermediate diffuser 15 is not deformed because the outer peripheral portion is sandwiched between the connecting structures to the turbine casing 12 although the detailed illustration is omitted. Needless to apply. Further, the downstream side of the downstream diffuser 16 is connected to the flue via a thermal elongation absorbing means that absorbs thermal elongation on the downstream side, although not shown in the figure. Needless to apply. Therefore, the present invention can be applied to any flange coupling portion of the upstream diffuser 14, the intermediate diffuser 15, and the downstream diffuser 16 when the connecting structure and the thermal elongation absorbing means are not provided.

1 is a schematic longitudinal side view showing a first embodiment of gas turbine equipment according to the present invention. FIG. 2 is an enlarged longitudinal sectional view taken along line AA in FIG. 1. The expanded sectional view which follows the BB line of FIG. FIG. 4 is an enlarged perspective view of the washer shown in FIG. 3. FIG. 5 is a view corresponding to FIG. 4 showing a second embodiment of the gas turbine equipment according to the present invention. FIG. 5 is a view corresponding to FIG. 2 to which the washer of FIG. 4 is applied. FIG. 3 is a view corresponding to FIG. 3 taken along line CC in FIG. 6. FIG. 4 is a view corresponding to FIG. 4 showing a third embodiment of the gas turbine equipment according to the present invention. FIG. 9 is a view corresponding to FIG. 2 to which the washer of FIG. 8 is applied. FIG. 10 is a view corresponding to FIG. 3 taken along line DD of FIG. 9. The expansion perspective view which shows the volt | bolt protection sleeve used for 4th Embodiment of the gas turbine equipment by this invention. FIG. 12 is a view corresponding to FIG. 2 to which the bolt protection sleeve of FIG. 11 is applied. FIG. 13 is a view corresponding to FIG. 3 taken along line EE in FIG. 12.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Gas turbine equipment, 2 ... Air compressor, 3 ... Combustor, 4 ... Gas turbine, 5 ... Exhaust diffuser, 6 ... Rotating shaft, 7, 10 ... Moving blade, 8, 11 ... Stator blade, 9 ... Compressor Casing, 12 ... turbine casing, 13 ... transition piece, 14 ... upstream diffuser, 15 ... intermediate diffuser, 16 ... downstream diffuser, 14N, 15N, 16N ... inner cylinder, 14S, 15S, 16S ... outer cylinder, 15Fs, 16Fs , 15Fn, 16Fn ... flange, 15H, 16H ... bolt through hole, 17 ... gas turbine compartment, 19 ... bolt, 20 ... nut, 18, 21, 22 ... washer, 21F ... engagement portion, 23 ... bolt protection sleeve.

Claims (8)

  An air compressor that compresses and discharges air, a combustor that mixes and burns compressed air discharged from the air compressor and fuel supplied by fuel supply means, and combustion burned in the combustor A gas turbine driven by gas, and an exhaust diffuser comprising a cylindrical body connected to the gas turbine to guide exhaust gas discharged to the flue, and the exhaust diffuser cylinder is divided into a plurality of exhaust gas outflow directions, In a gas turbine facility in which a flange is formed at a split portion of a cylinder and a bolt is passed through and fastened with a nut, the flange is formed to have the same thin wall as the cylinder, and the flanges of adjacent cylinders A gas turbine equipment characterized in that a fastening part is brought into surface contact with a washer thicker than the thickness of a flange and fastened with a bolt and a nut.   An air compressor that compresses and discharges air, a combustor that mixes and burns compressed air discharged from the air compressor and fuel supplied by fuel supply means, and combustion burned in the combustor An upstream diffuser having a gas turbine driven by gas and an exhaust diffuser having a cylindrical body connected to the gas turbine and guiding exhaust gas discharged to a flue, the exhaust diffuser being flange-coupled to the gas turbine side And an intermediate diffuser that is flange-coupled to the upstream diffuser and has a flange joint with the upstream diffuser reinforced by a structure for connection to the gas turbine, and flange-coupled to the intermediate diffuser and thermally expanded to the flue A gas tank that is divided into three in the exhaust gas outflow direction to a downstream diffuser connected through an absorption means In the bin facility, the flange thickness of the intermediate diffuser and the downstream diffuser is formed to be the same thin wall as the cylinder constituting the intermediate diffuser and the downstream diffuser, and the washers that are thicker than the flange thickness are surface-contacted to these flanges. The gas turbine equipment is configured to be fastened with bolts and nuts.   An air compressor that compresses and discharges air, a combustor that mixes and burns compressed air discharged from the air compressor and fuel supplied by fuel supply means, and combustion burned in the combustor A gas turbine driven by gas, and an exhaust diffuser comprising a cylindrical body connected to the gas turbine to guide exhaust gas discharged to the flue, the exhaust diffuser cylinder is divided into a plurality of exhaust gas outflow directions, In a gas turbine facility in which a flange formed with a bolt through hole is formed in a divided portion of a cylindrical body and the flange is fastened with a bolt and a nut, the flange is formed to have the same thin wall as the cylindrical body and adjacent to the flange. It is configured so that a washer thicker than the flange thickness is brought into surface contact with the fastening portion of the flange of the cylindrical body and fastened with bolts and nuts, and the adjacent flange Bolts protective sleeve is mounted over the belt through hole, the gas turbine equipment characterized by being configured so as to penetrate the bolt into the bolt protective sleeve.   The gas turbine equipment according to claim 1, wherein the washer is welded to a flange.   4. The gas turbine equipment according to claim 1, wherein the washer has a square shape and a corner portion is in contact with an outer peripheral surface of the isobody.   The gas turbine equipment according to claim 1, wherein the washer has an engaging portion that engages with an outer peripheral portion of the flange.   The gas turbine equipment according to claim 1, wherein the washer is formed in a cylindrical shape.   The gas turbine equipment according to any one of claims 1 to 7, wherein the washer is formed to have a thickness three times as thick as the thickness of the cylindrical body.

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