The present embodiments are directed to methods of welding and articles modified by welding. More specifically, the present embodiments are directed to articles with weld turbulators and methods of providing articles with weld turbulators.
By disrupting the flow of a fluid over a surface, generally by disrupting what would otherwise be laminar flow along the surface into turbulent flow, a turbulator increases the rate of heat exchange between the fluid and the surface. Turbulators are conventionally provided in turbine applications to aid in the cooling of turbine components during service.
A turbulator may be formed in any of a number of different ways, depending on the application, the materials involved, and the contour of the surface. Prefabrication or machining of an article having a surface with one or more turbulators may provide the turbulators with a high degree of precision in their shape and location but may significantly increase the production cost and/or the production time of the article.
Formation of a weld turbulator on a surface by welding after fabrication of the surface may be less costly than prefabrication, but may require more time, allow for less precision in the shape and location of the turbulator, and may be difficult to form for certain surface contours.
Gas turbine combustors use sequential liner cooling to cool the back side of hot gas walls with impingement cooling or convective cooling. Cooling features, such as turbulators, may be provided on the back side of these hot gas walls, but these cooling features must be cast or milled out of a solid piece of metal. This is extremely time consuming, makes providing turbulators on the back side of hot gas walls prohibitively expensive, and limits the placement and shape of the turbulators. Conventional methods only provide straight cooling ribs on the cylindrical part of sequential liners. The complex geometry of the transition piece of a combustor severely limits the ability to provide a turbulator to a transition piece by conventional methods.
In an embodiment, a method of modifying an article includes welding a plurality of weld rows of weld beads on a surface of the article such that a gap is formed between each pair of neighboring weld rows of the plurality of weld rows. The method optionally includes welding a plurality of fill rows of fill beads on the surface of the article such that each fill row of the plurality of fill rows fills at least a portion of one of the gaps. The weld rows and the fill rows increase a thickness of the article at the surface, provide an uneven contour of the article, and operate as turbulators on the surface of the article.
In another embodiment, a component includes an article having a surface and a plurality of weld rows of weld beads on the surface of the article arranged such that a gap is formed between each pair of neighboring weld rows of the plurality of weld rows. The component optionally includes a plurality of fill rows of fill beads on the surface of the article arranged such that each fill row of the plurality of fill rows fills at least a portion of one of the gaps. The weld rows and the fill rows increase a thickness of the article at the surface, provide an uneven contour of the article, and operate as turbulators on the surface of the article.
Other features and advantages of the present invention will be apparent from the following more detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
Wherever possible, the same reference numbers will be used throughout the drawings to represent the same parts.
Provided are articles with weld turbulators and methods of providing articles with weld turbulators.
Embodiments of the present disclosure, for example, in comparison to concepts failing to include one or more of the features disclosed herein, increase the metal thickness of an article, a component, a liner of a turbine combustor, or a transition piece of a turbine combustor; increase a rate of heat transfer between a surface and a fluid flowing along the surface; increase a body stiffness of a transition piece; provide a cooling feature at the outside diameter (OD) surface of a liner; provide a cooling feature at the OD surface of a liner; permit manufacture of a liner, a transition piece, or a unibody component from a thinner sheet of material; increase the cooling on the OD of a transition piece while maintaining the same stiffness as in a conventional transition piece, provide a cost saving due to an easier fabrication with a thinner body, or combinations thereof.
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In some embodiments, the article 10 is a turbine component. In some embodiments, the material of the article is a superalloy. In some embodiments, the superalloy is an iron-based superalloy, a cobalt-based superalloy, or a nickel-based superalloy.
In some embodiments, the article 10 is a portion of a gas turbine combustor. Referring to
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Although the methods disclosed herein may be used to modify any surface 20 in need of an increased thickness at the surface 20, an uneven contour for the surface 20, an increase in the rate of heat transfer between the surface and a fluid flowing along the surface, or turbulators on the surface 20, the methods are particularly advantageous for OD surfaces of a liner 140 and a transition piece 120 of a combustor 100 for a gas turbine engine.
In some embodiments, the present methods permit the initial formation of a liner 140 and a transition piece 120 that are thinner than the existing or conventional components. A conventional liner 140 and a conventional transition piece 120 may be formed from a sheet material as thin as about 4.8 mm (about 0.188″). In some embodiments, the present liner 140 and transition piece 120 are formed from a sheet material having a thickness of less than 4.8 mm (about 0.188″), alternatively about 4.0 mm (about 0.157″), alternatively about 4.0 mm (about 0.157″) or less, alternatively about 3.2 mm (about 0.125″), alternatively about 3.2 mm (about 0.125″) or less, or any value, range, or sub-range therebetween. The thinner sheet provides an easier fabrication of the liner 140 and transition piece 120. In some embodiments, the sheet material is a sheet metal.
In some embodiments, a first welding step adds weld turbulators in the form of weld rows 12 on the OD surfaces 20 of both the liner 140 and the transition piece 120.
In some embodiments, a second welding step adds weld turbulators in the form of fill rows 16 on the OD surface 20 of the transition piece 120 in the gaps 14 between neighboring weld rows 12. In some embodiments, the same welder or same type of welder is used in the first welding as the second welding. In some embodiments, the welder is an arc welder. In some embodiments, the arc welder is a metal inert gas (MIG) welder. In some embodiments, the arc welder is a tungsten inert gas (TIG) welder. In some embodiments, the method provides the weld rows 12 and the fill rows 16 on the transition piece 120 in only about 30 minutes or less.
In some embodiments, the weld turbulators of weld rows 12 on the liner 140 replace machined ones for cost saving. In some embodiments, the weld turbulators of weld rows 12 and fill rows 16 on the transition piece 120 increase the metal thickness, increase the stiffness, and add a cooling feature on the transition piece 120.
In some embodiments, the spacing of the weld rows 12 on the surface 20 of the liner 140 is different than the spacing of the weld rows 12 on the surface 20 of the transition piece 120. In some embodiments, the spacing of the weld rows 12 on the liner 140 is about 7.6 mm (about 0.3″), alternatively in the range of about 6.4 mm (about 0.25″) to about 8.9 mm (about 0.35″), or any value, range, or sub-range therebetween, and the spacing of the weld rows 12 on the transition piece 120 is about 2.5 mm (about 0.1″), alternatively in the range of about 2.0 mm (about 0.08″) to about 3.0 mm (about 0.12″), or any value, range, or sub-range therebetween.
In some embodiments, there is no overlapping of the weld rows 12, which provides a lower heat input into the transition piece 120 to eliminate, reduce, or minimize a welding-induced distortion of the transition piece 120 during the method. In some embodiments, the method forms the weld rows 12 in a non-sequential order. In some embodiments, there is no overlapping of the fill rows 16. In some embodiments, the fill rows 16 provide a rough or uneven OD surface 20 to increase the cooling of the transition piece 120 during service. In some embodiments, the method forms the fill rows 16 in a non-sequential order.
While the invention has been described with reference to one or more embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. In addition, all numerical values identified in the detailed description shall be interpreted as though the precise and approximate values are both expressly identified.