Patent Application
20090013695
1. Technical Field
This disclosure generally relates to combustion sections of gas turbine engines.
2. Description of the Related Art
Cooling of materials that are used to form combustion sections of gas turbine engines is accomplished using various techniques. By way of example, some materials that are used to line combustion sections incorporate film-cooling holes that are drilled through the materials at relatively shallow angles. Cooling air is provided to a backside of these materials, thereby allowing the air to travel through the film-cooling holes and cool a surface of the material that is closest to the combusting fuel and air mixture. Unfortunately, such a technique tends to be relatively inefficient in the use of cooling air. Additionally, the use of such a technique can still result in “hot spots” that can produce cracks in the material and material loss due to oxidation.
Floatwall panel assemblies and related systems are provided. In this regard, an exemplary embodiment of a floatwall panel assembly comprises: a panel formed of porous ceramic material, the porous ceramic material exhibiting a porosity gradient along at least one of a length, a width and a depth of the panel, the panel lacking a substrate, formed of a material other than porous ceramic material, for supporting the porous ceramic material.
An exemplary embodiment of a combustion section of a gas turbine engine comprises: a floatwall panel assembly having a panel and a mount, the panel being formed of porous material, the porous material exhibiting a porosity gradient along at least one of a length, a width and a depth of the panel, the mount being configured to engage the panel and maintain the panel in a spaced relationship from a surface to which the panel is attached.
An exemplary embodiment of a gas turbine engine comprises: a combustion section having a combustor shell, a floatwall panel and a mount; the panel being attached to the combustor shell and spaced therefrom by the mount, the panel being formed of porous ceramic material, the porous ceramic material exhibiting a porosity gradient along at least one of a length, a width and a depth of the panel, the panel lacking a substrate.
An exemplary embodiment of a floatwall panel for a combustion section of a gas turbine engine comprises a porous material exhibiting a porosity gradient along at least one of a length, a width and a depth of the floatwall panel.
Other systems, methods, features and/or advantages of this disclosure will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and be within the scope of the present disclosure.
Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Floatwall panel assemblies and related systems are provided. In this regard, several embodiments will be described. In particular, several embodiments will be described that incorporate the use of floatwall panels that are used for lining combustion sections. Such a floatwall panel is formed of porous material, such as porous metal and/or ceramic, that can exhibit a porosity gradient. That is, porosity of the material can vary along one or more of a length, width and depth of the panel. In some embodiments, the porosity is engineered such that more transpiration cooling flow is provided at a portion of the panel that is expected to be exposed to higher temperatures within the combustion section. Thus, material with higher porosity can be provided in these locations, whereas other locations can be provided with material with lower porosity. This tends to provide a more efficient use of cooling airflow through the panel that can result in a requirement for less cooling air. As used herein, the term “porosity” refers to the number of pores per given volume and/or the size of pores.
A portion of combustion section 106 is depicted in
The combustor shell 204, which can be formed of various materials, such as metallic, ceramic and/or composite, incorporates impingement holes, e.g., hole 220, through which a flow of cooling air is provided. The cooling air exits the impingement holes and disperses within a gap 222 defined between an underside 224 (or combustor shell side) of the floatwall panel and wall 202 of the combustor shell. From the gap, the cooling air transpires through the floatwall panel from the underside to a hot section side 226 of the panel, where the air enters a gas flow path 228 of the combustion section. Notably, the floatwall panel exhibits a porosity that accommodates placement of the panel in the combustion section.
In this regard, temperature within a combustion section is typically location dependent. That is, some locations within a combustion section tend to experience hotter temperatures than do others. Those locations that tend to experience the hottest temperatures are generally referred to as hot spots.
In the embodiment of
In contrast, the third region 234 incorporates two layers of disparate porosity. Specifically, a layer 240 located closest to the combustor shell exhibits a higher porosity along its length, width and depth than an adjacent layer 242, which is located closest to the gas flow path 228. By locating the material of the panel exhibiting lower porosity adjacent to the gas flow path, the pores of the material may be small enough to prevent blockage by particles that could be present in the gas flow path.
It should be noted that floatwall panels may be formed of various materials, such as porous metal, composites and/or ceramics. More information regarding porous metal and/or ceramics can be found in U.S. Published Patent Application 2005/0249602, which is incorporated by reference herein. In contrast, however, to some of the embodiments described in that application, floatwall panels may not involve the use of metal substrates.
As mentioned above, various techniques can be used for mounting a floatwall panel within a combustion section. Representative techniques are depicted schematically in
As shown in
In order to mount the floatwall panel to a wall of a combustion section, the rail is positioned to extend outwardly from the wall (not shown) and the panel is slid over the rail, thereby capturing the distal, protruding portion of the rail within the slot. Notably, in other embodiments, more than one slot and rail can be used per panel.
Another embodiment of a floatwall panel assembly attachment is depicted schematically in
In contrast to the embodiments of
Another embodiment of a floatwall panel assembly attachment is depicted schematically in
It should be emphasized that the above-described embodiments are merely possible examples of implementations set forth for a clear understanding of the principles of this disclosure. Many variations and modifications may be made to the above-described embodiments without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the accompanying claims.
