Patent Application
20250163827
The present disclosure relates to components in turbine engines and, more particularly, to a separator for high pressure coolant air fed to turbine components.
Gas turbine engines, such as those that power modern commercial and military aircraft and those that are used for land-based power generation, include a compressor section to pressurize a supply of air, a combustor section to burn a fuel in the presence of the pressurized air, and a turbine section to extract energy from the resultant combustion gases to generate thrust or electrical power.
Air exiting a high-pressure combustor of a gas turbine engine may carry debris, which often enters cooling passages for a blade outer air seal (BOAS). The presence of such debris may decrease cooling air provided to the BOAS, thereby reducing cooling effectiveness, which can lead to increased metal temperatures, and increasing a pressure ratio. A reduced cooling effectiveness and an increased pressure ratio may lead to premature oxidation, thermo-mechanical fatigue (TMF) failure, and creep.
In one non-limiting configuration, the present disclosure relates to a separator system for a blade outer air seal cooling passage of a gas turbine engine, comprising a cooling passage defined between an engine casing on a radially outer boundary and alternating blade outer air seals and vanes on a radially inner boundary; and a support positioned along the cooling passage and dividing the cooling passage into an upstream portion and a downstream portion; wherein the support further comprises at least one cyclonic separator having a flow inlet opening to the upstream portion, and having a filtered air outlet feeding to the downstream portion, and a particulate outlet for particles separated from flow through the cyclonic separator.
In a non-limiting configuration, the particulate outlet is connected to an accumulation point within +/−10 degrees of a bottom dead center (BDC) of the engine casing.
In another non-limiting configuration, the system further comprises a water flush assembly communicated with the particulate outlet to flush particles to the accumulation point.
In still another non-limiting configuration, the system further comprises a valve for removal of particles when the gas turbine engine is not in normal operation.
In a further non-limiting configuration, the valve is located at the accumulation point.
In a still further non-limiting configuration, the cooling passage is defined circumferentially whereby separated particles can travel by gravity to the accumulation point.
In another non-limiting configuration, the support is a full hoop structure that extends around a circumference within the engine casing.
In still another non-limiting configuration, the full hoop structure is a compliant seal support.
In a further non-limiting configuration, the compliant seal support is positioned to support a radially outer compliant seal and a radially inner compliant seal, wherein the radially outer compliant seal and the radially inner compliant seal define a passage therebetween for air flow from the filtered air outlet.
In a still further non-limiting configuration, the at least one cyclonic separator comprises a plurality of cyclonic separators spaced around the circumference.
In another non-limiting configuration, the at least one cyclonic separator is integrally defined with the support.
In still another non-limiting configuration, the blade outer air seal comprises a plurality of blade outer air seals including a first upstream blade outer air seal, and the support is axially positioned downstream of the first upstream blade outer air seal.
In a further non-limiting configuration, the support is axially positioned upstream of a second blade outer air seal that is downstream of the first blade outer air seal.
In a still further non-limiting configuration, the system further comprises a plurality of vanes alternatingly positioned between rotors that seal against the plurality of blade outer air seals, and wherein the support is axially positioned downstream of the first upstream blade outer air seal and upstream of a first upstream vane.
In another non-limiting configuration, the filtered air outlet is connected to a vane cooling space defined between a vane outer flange and the engine casing.
In still another non-limiting configuration, the particulate outlet for particles is routed to a surface or an internal passage within the support.
In a further non-limiting configuration, the support defines a circumferential flow path for the particles, wherein the circumferential flow path leads to a valve for removal of particles when the gas turbine engine is not in normal operation.
In a still further non-limiting configuration, the circumferential flow path for the particles is defined within the support.
In another non-limiting configuration, the cyclonic separator comprises a cylindrical body having a conically tapered end, and further comprises a radially oriented inlet to the cylindrical body, a first axially oriented outlet from the cylindrical body, and a second axially oriented outlet from the conically tapered end.
In still another non-limiting configuration, the radially oriented inlet defines the flow inlet opening to the upstream portion, the first axially oriented outlet defines the filtered air outlet feeding to the downstream portion, and the second axially oriented outlet defines the particulate outlet for particles separated from flow through the cyclonic separator.
The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements, as well as the operation thereof, will become more apparent in light of the following description and the accompanying drawings. It should be appreciated that the following description and drawings are intended to be exemplary in nature and non-limiting.
The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may best be obtained by referring to the detailed description and claims when considered in connection with the drawing figures, wherein like numerals denote like elements.
The detailed description of embodiments herein makes reference to the accompanying drawings, which show embodiments by way of illustration. While these embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, it should be understood that other embodiments may be realized and that logical, chemical, and mechanical changes may be made without departing from the spirit and scope of the disclosure. Thus, the detailed description herein is presented for purposes of illustration only and not for limitation. For example, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option. Further, any steps in a method discussed herein may be performed in any suitable order or combination. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact. It should also be understood that unless specifically stated otherwise, references to “a,” “an,” or “the” may include one or more than one and that reference to an item in the singular may also include the item in the plural. Further, all ranges may include upper and lower values and all ranges and ratio limits disclosed herein may be combined.
As stated previously, air exiting a high-pressure combustor of a gas turbine engine may carry debris, which often enters cooling passages of a blade outer air seal (BOAS). The presence of such debris may decrease cooling air provided to the BOAS, thereby reducing cooling effectiveness (resulting in increased metal temperatures) and increasing pressure ratio. A reduced cooling effectiveness and an increased pressure ratio may lead to premature oxidation, thermo-mechanical fatigue (TMF) failure, and creep.
Disclosed herein is a cyclonic separator system for separating debris such as particles or other particulate matter that may be entrained in the air exiting the combustor. The separator may be positioned in structures defining the cooling passages for interspersed BOAS and static vane structures. These cooling passages can be between an outer diameter of the BOAS or vane structures and an engine casing or turbine case. The cooling passages allow cooling air to pass through while the cyclonic separators separate debris particulates from the cooling air.
Gas turbine engine 20 may be a two-spool turbofan that generally incorporates a fan section 22, a compressor section 24, a combustor section 26, and a turbine section 28. In operation, fan section 22 may drive fluid, for example air, along a path of bypass airflow B while compressor section 24 may drive the fluid along a core flow path P for compression and communication into combustor section 26 then expansion through turbine section 28. Although depicted as a turbofan gas turbine engine 20 herein, it should be understood that the concepts described herein are not limited to use with turbofans as the teachings may be applied to other types of turbine engines.
Gas turbine engine 20 may generally include a low-speed spool 30 and a high-speed spool 32 mounted for rotation about an engine central longitudinal axis A-A′ relative to an engine static structure 36 or engine case via several bearing systems 38, 38-1, 38-2, etc. Engine central longitudinal axis A-A′ is oriented in the y-direction on the provided X-Y-Z axes. It should be understood that various bearing systems 38 at various locations may alternatively or additionally be provided, including for example, bearing system 38, bearing system 38-1, bearing system 38-2, etc.
Low-speed spool 30 may generally include an inner shaft 40 that interconnects a fan 42, a low-pressure compressor 44, and a low-pressure turbine 46. Inner shaft 40 may be connected to fan 42 through a geared system 48 that may drive the fan 42 at a lower speed than low-speed spool 30. Geared system 48 may include a gear assembly enclosed within a gear housing. Geared system 48 couples the inner shaft 40 to a rotating fan structure. The geared architecture 48 can include a gear assembly 60 enclosed within a gear housing 62. The gear assembly 60 couples the inner shaft 40 to a rotating fan structure.
High-speed spool 32 may include an outer shaft 50 that interconnects a high-pressure compressor 52 and high-pressure turbine 54. A combustor section 56 may be located between high-pressure compressor 52 and high-pressure turbine 54. A mid-turbine frame 57 of engine static structure 36 may be located generally between high-pressure turbine 54 and low-pressure turbine 46. Mid-turbine frame 57 may support one or more bearing systems 38 in turbine section 28. Inner shaft 40 and outer shaft 50 may be concentric and rotate via bearing systems 38 about the engine central longitudinal axis A-A′, which is collinear with their longitudinal axes. As used herein, a “high pressure” compressor or turbine experiences a higher pressure than a corresponding “low pressure” compressor or turbine.
The core airflow may be compressed by low-pressure compressor 44 then high-pressure compressor 52, mixed and burned with fuel in the combustor section 56, then expanded over high-pressure turbine 54 and low-pressure turbine 46. The mid-turbine frame 57 includes airfoils 59 which are in the core airflow path C. Turbines 46, 54 rotationally drive the respective low-speed spool 30 and high-speed spool 32 in response to the expansion. It will be appreciated that each of the positions of the fan section 22, compressor section 24, combustor section 26, turbine section 28, and geared system 48 may be varied. In various embodiments, geared system 48 may be located aft of combustor section 26 or even aft of turbine section 28, and fan section 22 may be positioned forward or aft of the location of geared system 48.
With reference now to
A blade outer air seal (BOAS) 208 is located radially outward from the first rotor blade 200. The high-pressure turbine 54 may include multiple BOAS 208 positioned radially outward of a plurality of rotor blades, and
A shroud block 210 (which may also be referred to as a support 210) may be positioned radially outward from the BOAS 208 and may couple the BOAS 208 to the frame 214. The shroud block 210 may resist movement of the BOAS 208 relative to the frame 214. Stated differently, the shroud block 210 may retain the BOAS 208 in place relative to the frame 214. As shown in
As mentioned above, the rotor blades 200, 204, the first vane 201, the second vane 202, and the BOAS 208 may be exposed to the core airflow C of
Still referring to
Air fed to the cooling flow path 218 typically can come from the compressor and, as mentioned above, can contain particulates and other matter that can foul cooling holes and surfaces of the cooling passage and interfere with the intended cooling.
Separators 216 can be positioned along cooling flow path 218 to remove dirt or other particulate matter from the flow of cooling air entering cooling flow path 218.
Complaint seals 220 are supported by a support 222, which can have walls arranged and configured to support the seals as desired. Typically there are flow passages through support 222 to allow cooling flow as intended.
Flow enters a cylindrical body portion of separator 226 and flows in a circular pattern. The air flows to vortex finder 234 and exits outlet 230, while the particulate is separated be secondary flow through conically tapered portion of separator 226 toward particulate outlet 232. Air leaving outlet 230 can be substantially dirt and particle free air circles into vortex finder 234 leading to outlet 230 for the clean air flow, while particles are driven to outlet 232 where they are routed to a suitable location for removal as will be discussed below.
Referring back to
It should be noted that separators 226 can be separately installed into W-seal support 222, or alternatively could be manufactured into support 222, for example through additive manufacturing. Such a manufacturing technique results in a structure wherein separators 226 are integrally incorporated into W-seal support 222. In the illustration of
At typical pressure differences across W-seal support 222, air flow can be readily driven through cyclonic separators to result in sub 3 μm filtration and a pressure drop of only about 2.5 psid. Further, if separators are positioned between the upstream most vane 201 and upstream most rotor blade 200 (
Flow from outlet 232 can be configured, for example with configuration of the structure of separator 226, to direct particulate matter as desired. Further, this particulate matter is directed to dump drain valve 238 such that, during downtime of the overall assembly or engine, particulate matter can be removed. In one configuration, flow to the dump drain may be carried out at a relatively low flow rate while the engine is operating, for example to minimize losses. During idle and shutdown, flow to the dump drain may be substantially increased, for example with additional fluid, for example liquid (e.g., water), flow, thus forcing any accumulation to purge more completely, without substantial operating inefficiency. This condition may also occur during start up, or during specific maintenance test runs, including water-wash cleanings.
Turning now to
In some instances the accumulation area for example at dump drain/valve 238 can become filled with particles. When this occurs, it may be desirable to provide for a portion of particulate matter to be re-introduced back into the cooling passage where it is diluted by flow through the cooling passage. This recycling of the particulate may in some instances be preferable to overflowing of dump drain 238.
Typically, during operation of the gas turbine engine, the percent of cooling flow is 50%-75% of the total local flow needed to support both cooling and cumulative leakages. Thus the clean exit of the separators may be sized to flow 50%-75% of the total air mass flow, and the remaining 50%-25% of air mass flow would have the majority of dirt particles. Thus, separators 226 and flow configuration surrounding them can be set such that between 50 and 75% of the total air mass flow flows through the clean air exits of the separators, and between 25 and 50% of the total air mass flow flows through the particulate or dirty air outlets.
It should be noted that since the cyclonic separators as disclosed herein will be exposed to cooling air that itself is still relatively high in temperature, as well as high temperature conditions from further inward, the separators, like other structures in this portion of the engine, should comprise materials which are stable under expected conditions.
The foregoing description is exemplary of the subject matter of the subject matter disclosed herein. Various non-limiting embodiments are disclosed, however, one of ordinary skill in the art would recognize that various modifications and variations in light of the above teachings will fall within the scope of the appended claims. It is therefore to be appreciated that within the scope of the appended claims, the disclosure may be practiced other than as specifically described. Thus, the scope of the present claims is not specifically limited by the details of specific embodiment disclosed herein, but rather the claims define the full and reasonable scope of the disclosure.
