JP6025546B2 - Turbine blade and turbine - Google Patents

Description

  The present invention relates to a turbine blade having a blade body fixed to a rotor and extending in the radial direction, a shroud provided on the blade body and connecting adjacent blade bodies, and a turbine having the turbine blade. is there.

  Turbine blades such as stationary blades and moving blades constituting the gas turbine are exposed to a high-temperature working fluid during operation of the gas turbine. Therefore, the shroud may be damaged in the turbine blades as the gas turbine is operated for a long time. When the damage of the shroud progresses, repair becomes impossible due to burning or thinning of the shroud, and turbine blades need to be discarded and replaced. Therefore, in order to prevent the cost increase associated with the disposal and replacement of such turbine blades and to use the turbine blades for a long period of time, the turbine blades are regularly inspected, and the shrouds are shrouded at an early stage. We are trying to repair the damage that occurred.

  Here, when periodically inspecting the turbine blades, first, the turbine blades are once removed from the rotor and the casing, and the degree of damage generated in the shroud is measured. Specifically, the shroud is obtained by applying a heat-resistant and thermal barrier coating on the surface of a base material made of metal or the like, and measures the length of a crack generated in the thermal barrier coating. Then, the measured length of the crack is compared with data accumulated in advance regarding the relationship between the length of the crack and the necessity of repair or disposal. As a result, whether or not the shroud needs to be repaired is determined based on whether or not the measured crack length exceeds a predetermined repair reference value (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-293049

  However, the conventional turbine blades have a problem in that a considerable number of turbine blades that are discarded due to significant damage including the shroud exist, leading to an increase in cost. That is, in order to determine whether or not the conventional turbine blade needs to be repaired, it is necessary to remove the turbine blade from the rotor or casing in order to measure the degree of damage to the shroud during periodic inspection of the gas turbine. However, some periodic inspections of the gas turbine are intended to inspect parts other than the turbine blades, and in such inspections, the turbine blades remain fixed without being removed from the rotor or casing. Therefore, even if damage is found in the shroud in such an inspection, it is not possible to determine whether the damage needs to be repaired. Then, when the turbine blades are removed and inspected in subsequent periodic inspections, the damage has progressed so that the turbine blades cannot be repaired, and the turbine blades need to be discarded and replaced.

  The present invention has been made in consideration of such circumstances, and the purpose of the present invention is to make it possible to easily determine the necessity of repair by visual inspection without removing the turbine blade from the rotor or casing. It is to provide a means to do.

In order to achieve the above object, the present invention provides the following means.
The turbine blade of the present invention is a turbine blade including a blade body extending in a radial direction of a rotor, and a shroud provided on at least one of a proximal end portion and a distal end portion of the blade body, and the blade in the shroud has a gap along the outer edge of the surface on the side of the body, have a repair reference portion being formed by a paint layer, the repair reference section, forms a linear shape extending along the outer edge, the components of the paint layer Is a fluorescent paint that is excited by light of a specific wavelength .

  According to the above configuration, a crack may occur from the outer edge of the surface of the shroud on the blade main body side with the operation for a long time, and the crack may extend in a direction substantially orthogonal to the outer edge. Even in that case, by checking whether or not the crack has reached the repair reference value, the inspector can visually determine whether or not the turbine blade needs to be repaired.

  According to the said structure, confirmation when the paint layer is exposed by the crack becomes easier.

  In the turbine blade, a coating layer is preferably formed on the surface of the shroud and the repair reference portion.

  According to the said structure, there is no possibility that a repair reference | standard part may lose | disappear when exposed to a high temperature working fluid.

  A turbine blade according to the present invention includes any one of the turbine blades described above.

  According to such a configuration, with the operation for a long time, a crack may be generated from the outer edge of the surface of the shroud on the blade body side, and the crack may extend in a direction substantially orthogonal to the outer edge. Even in that case, by checking whether or not the crack has reached the repair reference portion, the inspector can visually determine whether or not the turbine blade needs to be repaired.

  According to the present invention, it is possible to easily determine the necessity for repair visually without removing the turbine blade from the rotor or casing.

It is a whole lineblock diagram showing a gas turbine provided with a turbine stationary blade concerning a first embodiment of the present invention. It is a schematic perspective view which shows the external appearance of the turbine stationary blade which concerns on 1st embodiment of this invention. It is a schematic sectional drawing which shows the AA cross section in FIG. 2 about the base end side shroud which concerns on 1st embodiment of this invention. It is explanatory drawing of the effect of the turbine stationary blade which concerns on 1st embodiment of this invention. It is a schematic perspective view which shows the example which applied 1st embodiment of this invention to the turbine rotor blade. It is a schematic perspective view which shows the external appearance of the turbine stationary blade which concerns on 2nd embodiment of this invention. It is a schematic sectional drawing which shows the BB cross section in FIG. 6 about the base end side shroud which concerns on 2nd embodiment of this invention. It is a schematic perspective view which shows the example which applied the repair reference line to the shroud segment which consists of a some shroud.

[First embodiment]
Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, a turbine stationary blade of a gas turbine will be described as an example of a turbine blade according to the present invention. FIG. 1 is an overall configuration diagram illustrating a gas turbine 1 including a turbine stationary blade 10 according to a first embodiment. The gas turbine 1 is provided at the most upstream position along the fluid flow direction F to generate compressed air, and provided downstream thereof to inject fuel into the compressed air for combustion. Are provided with a combustor 3 that generates combustion gas, and a turbine 4 that is provided downstream of the combustor 3 and is driven to rotate by the combustion gas.

  As shown in FIG. 1, the turbine 4 is provided on the outer periphery of the rotor 5 and has a combustion gas flow passage formed therein, and protrudes from the outer peripheral surface of the rotor 5 at predetermined intervals in the circumferential direction. The plurality of turbine rotor blades 42 and the plurality of turbine stationary blades 10 projecting from the inner peripheral surface of the turbine casing 41 and provided at predetermined intervals in the circumferential direction are provided. The turbine rotor blade 42 and the turbine stationary blade 10 are provided with a plurality of stages alternately along the axial direction of the rotor 5.

  The turbine vane 10 serves to decelerate the combustion gas and increase its pressure. Here, FIG. 2 is a schematic perspective view showing the appearance of the turbine stationary blade 10. The turbine vane 10 has a streamlined cross section and has a blade body 11 extending in the radial direction of the rotor 5 shown in FIG. 1, a tip shroud 12 provided at the tip of the blade body 11, and a base end of the blade body 11. And a proximal-side shroud 13 provided in the section.

(Tip shroud)
The tip shroud 12 plays a role of connecting a plurality of turbine stationary blades 10 provided in the circumferential direction to each other at the tip. As shown in FIG. 2, the tip side shroud 12 includes a main body portion 14 as a housing and a pipe group 15 protruding upward from the main body portion 14.

(Piping group)
The piping group 15 plays a role of supplying the cooling gas CA to the turbine stationary blade 10 or discharging the cooling gas CA from the turbine stationary blade 10. As shown in FIG. 2, the pipe group 15 is provided so as to protrude from the central portion of the main body 14, and discharge pipes 151 for discharging the cooling gas CA from the turbine vane 10, and both sides sandwiching the discharge pipes 151. The first supply pipe 152 and the second supply pipe 153 are provided so as to protrude from the position and supply the cooling gas CA to the turbine stationary blade 10.

  As shown in FIG. 2, the discharge pipe 151 is a pipe having a substantially circular cross section. The discharge pipe 151 passes through the main body 14 and has one end opened upward and the other end connected to the internal cavity of the wing body 11. (Not shown in FIG. 2). As a result, the inside and the outside of the wing body 11 communicate with each other through the discharge pipe 151.

  As shown in FIG. 2, the first supply pipe 152 is a pipe having a substantially circular cross section. The first supply pipe 152 passes through the main body 14 and has one end opened upward and the other end opened inside the main body 14. Yes. As a result, the inside and the outside of the main body 14 are in communication with each other via the first supply pipe 152.

  The second supply pipe 153 is a pipe having a substantially triangular cross section as shown in FIG. 2, and penetrates the main body part 14 and has one end opening on the surface of the main body part 14 and the other end inside the wing main body 11. It is connected to the cavity (not shown in FIG. 2). As a result, the inside and outside of the blade main body 11 communicate with each other via the second supply pipe 153.

  The number of pipes constituting the pipe group 15 and the installation positions thereof are not limited to the present embodiment, and the design can be changed as appropriate according to the internal configuration of the blade body 11 and the like.

(Proximal end shroud)
The proximal-side shroud 13 plays a role of connecting a plurality of turbine stationary blades 10 provided in the circumferential direction to each other at the proximal end portion. Here, FIG. 3 is a schematic sectional view showing an AA section in FIG. 2. The proximal shroud 13 includes a base material 16 made of an alloy formed in a box shape, a pair of repair reference lines 18 applied to the wing body side surface 13a having a substantially rectangular shape in plan view, a repair reference line 18 and And a thermal barrier coating layer 17 covering the surface of the base material 16.
The base material 16 is made of an alloy such as IN738LC, MarM247LC, MGA1400.

  The repair reference line 18 is a paint layer formed by applying paint directly to the surface of the base material 16, and is substantially spaced from the outer edge 19 at a predetermined interval G from the outer edge 19 on the long side of the wing body side surface 13 a. Each extends in parallel. A component of the repair reference line 18 is a fluorescent paint that is excited by reacting with ultraviolet rays (excitation light), and can emit light by irradiating the ultraviolet rays.

  Note that the interval between the repair reference line 18 and the outer edge 19 is the data accumulated in advance regarding the relationship between the length of the crack generated on the blade body side surface 13a and the necessity for repair and disposal of the turbine stationary blade 10 (repair). It may be determined based on (reference value). The components of the repair reference line 18 are not limited to those described above. For example, a paint that reacts with visible light and emits light, or a paint of a color (yellow, etc.) different from the base material 16 and the thermal barrier coating layer 17. It is good.

  The thermal barrier coating layer 17 serves to protect the base material 16 and the repair reference line 18 applied to the surface of the base material 16 from a high-temperature working fluid flowing through the flow path. The thermal barrier coating layer 17 covers the surface of the base material 16 and is formed with a uniform thickness.

Although not shown in detail in the drawing, the thermal barrier coating layer 17 has a bond coat layer provided so as to cover the surface of the base material 16 and a ceramic layer provided so as to further cover the surface of the bond coat layer. Yes. The bond coat layer serves to alleviate the difference in thermal expansion between the base material 16 and the ceramic layer. This bond coat layer can be formed, for example, by spraying a sprayed powder made of MCrAlY (M is Co, Ni, Fe, etc.) on the surface of the base material 16. On the other hand, the ceramic layer plays a role of shielding the heat of the high temperature working fluid. This ceramic layer can be formed, for example, by spraying a ZrO ₂ -based ceramic spray powder on the surface of the bond coat layer.

(Function and effect)
Next, the effect of the turbine stationary blade 10 according to the first embodiment of the present invention will be described. FIG. 4 is an explanatory diagram of the operational effects of the turbine stationary blade 10. When the gas turbine 1 is operated for a long time, the proximal-side shroud 13 of the turbine stationary blade 10 may be damaged. Examples of the damage generated in the base end side shroud 13 include cracking and peeling generated in the thermal barrier coating layer 17 or reduction in thickness due to oxidation and burning of the base material 16. Here, if such damage occurs in the proximal-side shroud 13, a crack 20 is generated in the outer edge 19 of the blade body side surface 13a as an indication thereof. And this crack 20 is extended in the direction substantially orthogonal to the outer edge 19 toward the center part from the outer edge 19 of the wing | blade main body side surface 13a.

  Here, an inspector who periodically inspects the gas turbine 1 may inspect parts other than the turbine stationary blade 10. In such a case, the inspector generates ultraviolet rays on the turbine stationary blade 10 fixed to the inner peripheral surface of the turbine casing 41 shown in FIG. It is visually confirmed whether or not the crack 20 has reached the repair reference line 18 that is the repair reference portion.

As a result, when the tip of the crack 20 has reached the repair reference line 18 as in the first crack 20a and the second crack 20b shown in FIG. 4, the inspector needs to repair the turbine stationary blade 10. It is determined that the damage has progressed to That is, when the first crack 20a and the second crack 20b progress beyond the repair reference line 18, the paint constituting the repair reference line 18 is exposed from between the cracks 20, and the paint is irradiated with ultraviolet rays. Since the light is emitted, the inspector can determine whether or not the length of the crack 20 exceeds a certain level.
In this case, the inspector removes the turbine stationary blade 10 from the turbine casing 41 and repairs various components of the turbine stationary blade 10 including the proximal end side shroud 13.

On the other hand, if the tip of the crack 20 has not yet reached the repair reference line 18 as in the third crack 20c shown in FIG. to decide. That is, since there is no exposure of the paint, light emission is not confirmed even if the inspector irradiates the crack 20 with ultraviolet rays, so that it can be determined that there is no need for replacement.
In this case, the inspector performs inspection and repair work only on the original inspection target portion without removing the turbine stationary blade 10 from the turbine casing 41.

  Thus, according to the turbine stationary blade 10 according to the first embodiment, it is only checked visually whether the crack 20 has reached the repair reference line 18 while being fixed to the turbine casing 41. By this work, it can be easily determined whether or not repair is necessary. Therefore, it is possible to easily find out that the turbine stationary blade 10 is damaged in a periodic inspection in which the original inspection target is a portion other than the turbine stationary blade 10.

  As a result, in the inspection for the turbine stationary blade 10, the damage can be found and repaired at an early stage before the damage to the extent that the proximal shroud 13 cannot be repaired is found. Therefore, it is possible to reduce the number of proximal shrouds 13 that are largely damaged and are disposed of by disposal, thereby reducing costs by reducing material costs.

Moreover, since it is not necessary to machine the base end side shroud 13 in forming the repair reference line 18, the formation cost of the repair reference line 18 can be reduced.
Further, since the repair reference line 18 is not formed by a step or the like, it does not hinder the flow of the working fluid flowing on the shroud.

(Modification)
In the present embodiment, the proximal-side shroud 13 has been described as an example. However, instead of this, the repair reference line 18 may be formed on the blade body side surface 12a of the distal-side shroud 12 shown in FIG. Good. Further, in the present embodiment, the turbine stationary blade 10 constituting the gas turbine 1 has been described as an example. However, the turbine stationary blade 10 illustrated in FIG. 1 can be applied. FIG. 5 is a schematic perspective view showing an example in which the present embodiment is applied to the turbine rotor blade 42. The turbine rotor blade 42 has a streamlined cross section and has a blade body 421 extending in the radial direction of the rotor 5 shown in FIG. 1 and a proximal shroud 422 (generally “ Platform)). A pair of repair reference lines 423 are formed on the blade body side surface 422a of the base end side shroud 422 at positions on both sides of the blade body 421.

[Second Embodiment]
Next, the configuration of the turbine blade according to the second embodiment will be described.
In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIGS. 6 and 7, the turbine blade 10 according to the present embodiment is characterized in that the repair reference portion forms the repair reference surface 18 </ b> B with a paint applied to one surface except the range of the gap G. It is said. That is, the repair reference surface 18B has a distance corresponding to the repair reference from the outer edge of the shroud, and is similar in shape to the outer shape of the blade body side surface 13a of the proximal end shroud.

  According to the turbine blade 10 according to the second embodiment, in addition to the effects of the turbine blade 10 according to the first embodiment, the repair reference portion is configured by a surface, so that the crack 20 is the repair reference of the first embodiment. When it is formed beyond the end portion of the repair reference surface 18B corresponding to the line 18, the paint is more exposed, so it is easier to determine whether or not the repair reference value has been reached.

  It should be noted that the shapes, combinations, operation procedures, and the like of the constituent members shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements and the like without departing from the spirit of the present invention. For example, in this embodiment, although the case where the turbine blade which concerns on this invention is applied to a gas turbine was demonstrated, it can replace with this and can be applied to a steam turbine.

Further, in the above-described embodiment, it is not always necessary to form the thermal barrier coating layer 17, and the repair reference line 18 or the repair reference surface 18B may be visible even when the crack 20 is not generated. .
Further, the repair reference line 18 is not limited to a position at a predetermined interval from the outer edge 19 on the longitudinal side of the wing body side surfaces 12a, 13a, 422a, but any one of the four sides of the wing body side surfaces 12a, 13a, 422a. What is necessary is just to provide in the position which left the predetermined space | interval from one or more outer edges.

  Furthermore, in each embodiment mentioned above, although the example which applies a repair reference | standard part to an independent shroud was shown, it is not restricted to this, The shroud which couple | bonded several shrouds as shown in FIG. 8 with fastening means, such as a volt | bolt. It can also be applied to segments. When applied to the shroud segment, the repair reference portion may be formed on the basis of the outer edge of the surface obtained by combining the two wing body side surfaces 13a as the target surface.

DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Compressor 3 Combustor 4 Turbine 5 Rotor 10 Turbine stationary blade 11 Blade body 12 Tip side shroud 12a Blade body side surface 13 Base end side shroud 13a Blade body side surface 14 Body portion 15 Piping group 151 Exhaust pipe 152 First supply Pipe 153 Second supply pipe 16 Base material 17 Thermal barrier coating layer 18 Repair reference line (repair reference section)
18B repair reference plane (repair reference section)
19 Outer edge 20 Crack 20a 1st crack 20b 2nd crack 20c 3rd crack 41 Turbine casing 42 Turbine blade 421 Blade body 422 Base end side shroud 422a Blade body side surface 423 Repair reference line CA Cooling gas F Flow direction

Claims (3)

A blade body extending in the radial direction of the rotor;
A shroud provided on at least one of the proximal end and the distal end of the wing body;
In a turbine blade comprising:
The wing having a gap along the outer edge of the surface on the side of the body, have a repair reference portion being formed by a paint layer in said shroud,
The repair reference portion has a linear shape extending along the outer edge,
A component of the paint layer is a fluorescent paint excited by light of a specific wavelength . The turbine blade according to claim 1 , wherein a coating layer is formed on surfaces of the shroud and the repair reference portion. A turbine comprising the turbine blade according to claim 1 .

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