The invention relates in general to turbine components that operate in high temperature flow environments and, more particularly, to components configured to minimize flow stagnation near such components and to provide enhanced heat distribution characteristics.
There are various applications in which one or more components can be exposed to high temperature flow conditions. For instance, many of the components in the combustor section of a turbine engine operate in such an environment. Such components can include head end plates, which are used to close off the combustor chamber, and can further be used to help centralize and align adjacent burners. An example of a head end plate 50 is shown in
Usually, such components contain internal cavities or passages through which a coolant can pass to provide relief from the extremely hot temperatures on the outside. Further, these components may also include sundry coatings to provide additional heat resistance. Despite these measures, there are two recurring problems associated with head end plates. One problem is that of low flow or stagnation zones substantially proximate to the head end plate. The other problem is that of superheated fluids, such as combustion gases, lingering near the head end plates and other components; prolonged exposure to these gases can result in part failure due to high thermal loads, especially at the corners and edges of these components which can act as heat sinks.
There are known methods for minimizing stagnation zones around adjacent components. One general example of such an arrangement is shown in
As will be described below, the edges and the corners 12 shown in
Numerous configurations, as shown in
Referring to
Yet another approach is to chamfer the outer corner or edges 32 of the component as shown in
None of the previously designs have successfully addressed both problems of flow stagnation and the undesirable heat concentrations that can occur at corners and/or edges of components exposed to high temperature flow environments. Thus, one object according to aspects of the present invention is to provide a system for such components that not only provides enhanced heat distribution properties at corner and/or edges regions but also avoids the problem of stagnant flow. These and other objects according to aspects of the present invention are addressed below.
Aspects of the present invention relate to system for reducing flow stagnation between substantially adjacent components while also enhancing heat distribution characteristics of the components, especially at the corners and/or edges of the components so as to minimize or avoid localized hot spots. The system includes a first component and a second component. Both the first and second components are generally hollow, and component has at least two walls disposed substantially orthogonal to each other. Each of the two or more walls has an interior surface and an exterior surface.
Further, each of the two walls includes a substantially planar region transitioning into a corner region. Each substantially planar region has an associated wall thickness. The exterior surfaces of the two walls join in the corner region to form an outer edge portion. The outer edge portion can culminate in a substantially 90 degree edge, or it can culminate in a substantially rounded edge. The interior surfaces of the two walls join in the corner region to define an inner edge portion. In the corner region, the interior surface of each wall approaches the exterior surface such that the edge thickness, that is, the distance between the inner edge and the outer edge, is less than or equal to the wall thickness.
The first and second components can be substantially adjacent such that the outer edge portions are disposed opposite and substantially parallel to each other. The first and second components can be disposed substantially laterally adjacent to each other. Alternatively, the first and second components can be disposed substantially circumferentially adjacent to each other. As a result, the adjacent outer edges reduce the stagnation of air flow around the first and second components, while the reduced thickness of the corner region provides enhanced heat transfer properties.
The first and second components can be turbine engine components such as head end plates for closing off at least a portion of the combustion chamber of the turbine engine. The hollow interior of the first and second components can be supplied with cooling air or other coolant, and the exterior surfaces of the walls of the first and second components can be exposed to high temperature gases.
In another respect, aspects of the invention can be applied to a component to enhance thermal distribution properties, independent of flow stagnation prevention. The component includes a generally hollow body having two walls disposed substantially orthogonal to each other. The component can be substantially rectangular. The substantially hollow body can have an inner volume that is supplied with a coolant. Each of the two walls has an interior surface and an exterior surface. Further, each of the two walls includes a substantially planar region transitioning into a corner region.
Each substantially planar region has an associated wall thickness, and the planar region of the two walls can have substantially identical thicknesses. The exterior surfaces of the two walls join in the corner region to form an outer edge or corner portion. The outer edge portion can culminate in a substantially 90 degree edge portion or in a substantially rounded edge portion. The two interior surfaces of the two walls join in the corner region to define an inner edge or corner portion. The interior surface of each wall in the corner region approaches the exterior surface as the interior surface advances toward the inner edge portion such that the thickness in the corner region does not exceed the thickness of the substantially planar region.
Aspects of the present invention relate to turbine components having one or more features that can avoid flow stagnation while also enhancing heat distributions at the corners and/or edges of the components to minimize or avoid localized hot spots. Aspects of the present Invention improve upon previous turbine component designs that failed to solve both problems.
Embodiments of the invention will be explained in the context of a head end plate for a turbine engine, but the detailed description is intended only as exemplary. Aspects according to the present invention can be applied to other situations in which two or more substantially adjacent components are subject to a superheated environment. Embodiments of the invention are shown in
Aspects of the present invention can be applied to any generally hollow body 58 having at least two walls 60,64 disposed substantially orthogonal to each other (
In the corner region 62, the exterior surfaces 68 of the two walls 60,64 join to form an outer edge portion 67. Also, in the corner region 62, the interior surfaces 66 of the two walls 60,64 join to define an inner edge portion 69. The interior surface 66 of each wall 60,64 in the corner region 62 approaches the exterior surface 68 as the interior surface 66 advances toward the inner edge portion 69 such that the thickness in the corner region 62 does not exceed the thickness of the substantially planar region 65.
Such an arrangement can provide enhanced heat distribution characteristics to the edge regions of a component. For example, a component having an edge configured according to aspects of the invention can achieve a temperature gradient between the inner and outer edges that is approximately 47% to 63% less than an edge without a reduced thickness according to principles of the invention. In absolute terms, the gradient reduction can range from about 56 to 99 degrees Celsius. The degree of the benefit can depend on the material thickness as well as on the location of the head end plate, such as whether it is located on the hot side or the cold side of the annular ring 56.
In one embodiment, the planar region 65 of the walls 60,64 can be of substantially identical thickness. However, when the planar regions 65 are of unequal thickness, then it is preferred if the thickness of the corner region 62 does not exceed the thickness of the smaller of the two substantially planar regions 65.
The outer edge or corner portion 67 can have a variety of configurations. For example, the outer portion 67 can culminate in a substantially 90 degree sharp edge. Alternatively, the outer edge portion 67 can culminate in a substantially rounded edge.
In one embodiment, the component 58 can be substantially rectangular in conformation (see
Such an arrangement can provide enhanced heat distribution characteristics to the corner 72 of a component. For example, a component having a corner configured according to aspects of the invention can achieve a temperature gradient between the inner and outer sides of a corner that is approximately 68% to 78% less those of a corner without a reduced thickness according to principles of the invention. In absolute terms, the gradient reduction can range from about 84 to 153 degrees Celsius. Again, the magnitude of the benefit can depend at least on the material thickness as well as on the location of the head end plate, such as whether it is located on the hot side or the cold side of the annular ring 56.
The component 58 can have a substantially hollow body that includes an inner volume. The inner volume can be supplied with a coolant. The coolant can be air, steam or other suitable fluid. The component 58 can be made of various materials including Hastalloy X or Inconel 939 (weldable version).
A component 58 having aspects according to the present invention can be made in a variety of ways. For example, the component 58 can be cast to have features according to aspects of the present invention such as having the interior surface 66 of each wall 60,64 in the corner region 62 approach the exterior surface 68 as the interior surface 66 advances toward the inner edge portion 69 so that the thickness in the corner region 62 does not exceed the thickness of the substantially planar region 65. Alternatively, the edge configurations according to aspects of the invention can be added to a component 58 using secondary processes such as machining, laser drilling or other material removal process. Again, these are merely examples of methods in which aspects of the present invention can be applied to a component.
A component having aspects according to the present invention can be used in a number of ways. For example, aspects of the present invention can be applied to one or more head end plates 50 in a turbine engine (
Regardless of the application, two or more components 58 are provided having at least one corner region 62 configured according to aspects of the present invention. The components 58 are substantially adjacent such that the outer edge portions 67 are disposed opposite and substantially parallel to each other (
Though aspects of the present invention have been discussed in connection with head end plates, one skilled in the art will appreciate how to apply aspects of the present invention to other turbine engine components and still other components outside of the turbine engine context. Thus, it will be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible within the scope of the invention as defined in the following claims.