Patent Description:
In one example, a combustor of a gas turbine engine may be configured to burn fuel in a combustion area. Such configurations may place substantial heat load on the structure of the combustor (e.g., heat shield panels, shells, etc.). Such heat loads may dictate that special consideration is given to structures, which may be configured as heat shields or panels, and to the cooling of such structures to protect these structures. Excess temperatures at these structures may lead to oxidation, cracking, and high thermal stresses of the heat shields panels.

<CIT> discloses a supply duct assembly for providing cooling air to a combustor section of a gas turbine engine. A diffuser located downstream of a compressor section directs air to the combustion section while a conduit formed between a radially inner shell and a radially outer shell directs cooling air flow to vanes and turbine rotors downstream of the combustor section. The distal end of the inlet to the cooling airflow conduit is located upstream of the diffuser. <CIT> discloses a turbine engine comprising first and second tangential onboard injectors configured to receive airflow from a compressor stage for cooling turbine blades and disk. <CIT> discloses a turbine engine wherein a flow path is provided adjacent a combustion section for directing bleed air from a compressor stage to the turbine stage for cooling. <CIT> discloses a turbine engine comprising a tangential onboard injector configured to receive mixed air from a compressor stage via a diffuser case and air circulated from the diffuser case to a cooling system for cooling the turbine section. <CIT> discloses a turbine engine wherein compressed air is supplied to a diffuser manifold where it is directed to a passageway radially inwardly of a diffuser case for a combustion section and to a turbine section where the air is used for cooling turbine blades.

Viewed from one aspect there is provided a diffuser case assembly for a gas turbine engine according to claim <NUM>.

According to an embodiment, a diffuser case assembly for a gas turbine engine is provided. The diffuser case assembly including: a pre-diffuser; a diffuser case defining a dump region, an inner plenum, and an outer plenum, the pre-diffuser being fluidly connected to the inner plenum and the outer plenum through the dump region; a tangential onboard injector module fluidly connected to the inner plenum through inlet orifice located in the diffuser case proximate an aft end of the inner plenum; and an inlet extender initiating at the inlet orifice of the tangential onboard injector module, extends through the inner plenum, and terminates at a distal end proximate the pre-diffuser, characterized in that the distal end of the inlet extender is located in the dump region.

A radially inward wall may at least partially define the inner plenum, and the inlet extender may be located proximate the radially inward wall.

The pre-diffuser may include a guide wall defining the pre-diffuser. The inlet extender proximate the distal end may be shaped to be about perpendicular to the guide wall of the pre-diffuser.

An angle between the guide wall of the pre-diffuser and the inlet extender proximate the distal end may be less than or equal to <NUM> degrees.

An angle between the guide wall of the pre-diffuser and the inlet extender proximate the distal end may be less than <NUM> degrees.

An angle between the guide wall of the pre-diffuser and the inlet extender proximate the distal end may be equal to <NUM> degrees.

An orifice may be located in the inlet extender fluidly connecting the first inner plenum and the second inner plenum; and a ramp may be located opposite the orifice.

A radially inward wall may at least partially define the inner plenum, and the inlet extender may be located proximate the radially inward wall. The ramp may extend away from the radially inward wall and towards the orifice.

A radially inward wall may at least partially define the inner plenum, and the inlet extender may be located proximate the radially inward wall. The ramp may be orientated at an angle relative to the radially inward wall, the angle may be less than <NUM> degrees as measured between the radially inward wall and an aft side of the ramp.

Viewed from another aspect there is provided a gas turbine engine according to claim <NUM>.

A gas turbine engine according to an embodiment includes: a pre-diffuser; a diffuser case defining a dump region, an inner plenum, and an outer plenum, the pre-diffuser being fluidly connected to the inner plenum and the outer plenum through the dump region; a combustor housed within the diffuser case between the inner plenum and the outer plenum; a tangential onboard injector module fluidly connected to the inner plenum through inlet orifice located in the diffuser case proximate an aft end of the inner plenum; and an inlet extender initiating at the inlet orifice of the tangential onboard injector module, extends through the inner plenum, and terminates at a distal end proximate the pre-diffuser, wherein the distal end of the inlet extender is located in the dump region.

The pre-diffuser may include a guide wall defining the pre-diffuser, and the inlet extender proximate the distal end may be shaped to be about perpendicular to the guide wall of the pre-diffuser.

The pre-diffuser may include a guide wall defining the pre-diffuser. An angle between the guide wall of the pre-diffuser and the inlet extender proximate the distal end may be less than or equal to <NUM> degrees.

An orifice located in the inlet extender may fluidly connect the first inner plenum and the second inner plenum; and a ramp may be located opposite the orifice.

The ramp may extend away from a radially inward wall of the diffuser case and towards the orifice.

The ramp may be orientated at an angle relative to a radially inward wall of the diffuser case, the angle may be less than <NUM> degrees as measured between the radially inward wall and an aft side of the ramp.

The detailed description explains embodiments of the present disclosure, together with advantages and features, by way of example with reference to the drawings.

In one disclosed embodiment, the engine <NUM> bypass ratio is greater than about ten (<NUM>:<NUM>), the fan diameter is significantly larger than that of the low pressure compressor <NUM>, and the low pressure turbine <NUM> has a pressure ratio that is greater than about five (<NUM>:<NUM>). The geared architecture <NUM> may be an epicyclic gear train, such as a planetary gear system or other gear system, with a gear reduction ratio of greater than about <NUM>: <NUM>. It should be understood, however, that the above parameters are only exemplary of one embodiment of a geared architecture engine and that the present disclosure is applicable to other gas turbine engines including direct drive turbofans.

The fan section <NUM> of the engine <NUM> is designed for a particular flight condition--typically cruise at about <NUM> Mach (<NUM>/s) and about <NUM>,<NUM> feet (<NUM>,<NUM> meters). The flight condition of <NUM> Mach (<NUM>/s) and <NUM>,<NUM> ft (<NUM>,<NUM> meters), with the engine at its best fuel consumption--also known as "bucket cruise Thrust Specific Fuel Consumption ("TSFC")"--is the industry standard parameter of lbm of fuel being burned divided by lbf of thrust the engine produces at that minimum point.

Referring now to <FIG>, with continued reference to <FIG>, the combustor section <NUM> of the gas turbine engine <NUM> is shown. The combustor <NUM> of <FIG> is an impingement film float wall combustor. It is understood that while an impingement film float wall combustor is utilized for exemplary illustration, the embodiments disclosed herein may be applicable to other types of combustors for gas turbine engines including but not limited to double pass liner combustors, float wall combustors, and combustors with single wall liners.

As illustrated, a combustor <NUM> defines a combustion chamber <NUM>. The combustion chamber <NUM> includes a combustion area <NUM> within the combustion chamber <NUM>. The combustor <NUM> includes an inlet <NUM> and an outlet <NUM> through which air may pass. The air may be supplied to the combustor <NUM> by a pre-diffuser <NUM>. Air may also enter the combustion chamber <NUM> through other holes in the combustor <NUM> including but not limited to quench holes <NUM>, as seen in <FIG>.

Compressor air is supplied from the compressor section <NUM> into a pre-diffuser <NUM>, which then directs the airflow toward the combustor <NUM>. The combustor <NUM> and the pre-diffuser <NUM> are separated by a dump region <NUM> from which the flow separates into an inner plenum <NUM> and an outer plenum <NUM> (also referred to herein as an inner shroud <NUM> and an outer shroud <NUM>). As air enters the dump region <NUM>, a portion of the air may flow into the combustor inlet <NUM>, a portion may flow into the inner shroud <NUM>, and a portion may flow into the outer shroud <NUM>.

The air from the inner shroud <NUM> and the outer shroud <NUM> may then enter the combustion chamber <NUM> by means of one or more primary apertures <NUM> in the shell <NUM> and one or more secondary apertures <NUM>, as shown in <FIG> and <FIG>. The primary apertures <NUM> and secondary apertures <NUM> may include nozzles, holes, etc. The air may then exit the combustion chamber <NUM> through the combustor outlet <NUM>. At the same time, fuel may be injected into the combustion chamber <NUM> through the primary and/or secondary orifices of a fuel injector <NUM> and a pilot nozzle <NUM>, which may be atomized and mixed with air, and then ignited and burned within the combustion chamber <NUM>. The combustor <NUM> of the engine combustion section <NUM> may be housed within diffuser case <NUM> which may define the inner shroud <NUM> and the outer shroud <NUM>.

The combustor <NUM>, as shown in <FIG>, includes multiple heat shield panels <NUM> that are attached to one or more shells <NUM>. The heat shield panels <NUM> may be arranged parallel to the shell <NUM>. The shell <NUM> includes a radially inward shell 600a and a radially outward shell 600b in a facing spaced relationship defining the combustion chamber <NUM> therebetween. The shell <NUM> also includes a forward shell 600c extending between the radially inward shell 600a and the radially outward shell 600b. The forward shell 600c further bounds the combustion chamber <NUM> on a forward end 300a of the combustor <NUM>. The radially inward shell 600a and the radially outward shell 600b extend circumferentially around the longitudinal engine axis A. The radially inward shell 600a is located radially inward from the radially outward shell 600b.

The heat shield panels <NUM> can be removably mounted to the shell <NUM> by one or more attachment mechanisms <NUM>. In some embodiments, the attachment mechanism <NUM> may be integrally formed with a respective heat shield panel <NUM>, although other configurations are possible. In some embodiments, the attachment mechanism <NUM> may be a threaded mounting stud or other structure that may extend from the respective heat shield panel <NUM> through the interior surface to a receiving portion or aperture of the shell <NUM> such that the heat shield panel <NUM> may be attached to the shell <NUM> and held in place. The heat shield panels <NUM> partially enclose a combustion area <NUM> within the combustion chamber <NUM> of the combustor <NUM>.

The combustor <NUM> also includes a forward dome <NUM> attached to the shell <NUM> at a forward end 300a of the combustor <NUM>. The forward end 300a is located opposite an aft end 300b of the combustor <NUM>, as illustrated in <FIG>. The forward dome <NUM> includes a curved dome portion <NUM> that is operably shaped or curved to direct a portion of the airflow from the pre-diffuser <NUM> around the forward dome <NUM> and into the inner shroud <NUM> and the outer shroud <NUM>. The forward dome <NUM> includes a radially inward linear portion <NUM> located on a radially inward side <NUM> of the forward dome <NUM> and a radially outward linear portion <NUM> located on a radially outward side <NUM> of the forward dome <NUM>. The radially inward linear portion <NUM> is linear in shape. The radially outward linear portion <NUM> is linear in shape. The forward dome <NUM> transitions from the curved dome portion <NUM> to the radially inward linear portion <NUM> at a radially inward transition point <NUM>, which may be a bend in the forward dome <NUM>, as illustrated in <FIG>. The forward dome <NUM> transitions from the curved dome portion <NUM> to the radially outward linear portion <NUM> at a radially outward transition point <NUM>, which may be a bend in the forward dome <NUM>, as illustrated in <FIG>.

Referring now to <FIG>, <FIG>, with continued reference to <FIG>, an inlet extender <NUM> extending from an inlet orifice <NUM> of a tangential onboard injector (TOBI) module <NUM> is illustrated, according to an embodiment of the present disclosure. The TOBI module <NUM> is configured to distribute cooling airflow <NUM> from the inner shroud <NUM> to the turbine section <NUM> of the gas turbine engine <NUM>.

Blades of turbine section <NUM> of gas turbine engines <NUM>, as well as other components of the turbine section <NUM>, experience elevated heat levels during operation. Impingement and/or convective cooling of the turbine section <NUM> may be used to help cool components within the turbine section <NUM>. Convective cooling may be achieved by airflow <NUM> that is channeled from the TOBI module <NUM> to the turbine section <NUM>.

The cooling airflow <NUM> may contain particulates <NUM>, which may build up on the components of the turbine section <NUM> overtime, thus reducing the cooling ability of the cooling airflow <NUM>. Embodiments disclosed herein seek to address particulate adherence to components within the turbine section <NUM> in order to maintain the cooling ability of the cooling airflow <NUM> by reducing particulate <NUM> entry into the TOBI module <NUM>. Particulate <NUM> may include but is not limited to dirt, smoke, soot, volcanic ash, or similar airborne particulate known to one of skill in the art.

As illustrated in <FIG>, the inlet orifice <NUM> of the TOBI module <NUM> is located proximate an aft end <NUM> of the inner shroud (plenum) <NUM>. The inlet orifice <NUM> may be an opening or orifice in the diffuser case <NUM> that fluidly connects the inner shroud <NUM> to the TOBI module <NUM>.

The inlet extender <NUM> is interposed between the combustor <NUM> and the radially inward wall <NUM> of the diffuser case <NUM>. The inlet extender <NUM> initiates at the inlet orifice <NUM> of the TOBI module <NUM>, extends through the inner shroud <NUM>, and terminates at a distal end <NUM> proximate the pre-diffuser <NUM>. As illustrated in <FIG>, the inlet extender <NUM> may separate the inner shroud <NUM> into a first inner shroud (plenum) 114a and a second inner shroud (plenum) 114b. In one embodiment, the inlet extender <NUM> may fluidly separate the inner shroud <NUM> into the first inner shroud 114a and the second inner shroud 114b. The inlet orifice <NUM> is fluidly connected to the first inner shroud 114a. The first inner shroud 114a is located proximate a radially inward wall <NUM> of the diffuser case <NUM> and radially inward of the second inner shroud 114b. The second inner shroud 114b is located proximate the combustor <NUM> and radially outward of the first inner shroud 114a. The inlet extender <NUM> may be substantially shaped to follow a curvature of the radially inward wall <NUM> of the diffuser case <NUM>. The inlet extender <NUM> proximate the distal end <NUM> may be shaped to be about perpendicular to a guide wall <NUM> of the pre-diffuser <NUM>. The guide wall <NUM> defines the pre-diffuser <NUM>. In an embodiment, an angle α1 between the guide wall <NUM> of the pre-diffuser <NUM> and the inlet extender <NUM> proximate the distal end <NUM> may be less than or equal to <NUM> degrees. As illustrated in <FIG>, the angle α1 between the guide wall <NUM> of the pre-diffuser <NUM> and the inlet extender <NUM> proximate the distal end <NUM> may be about equal to <NUM> degrees. As illustrated in <FIG>, the angle α1 between the guide wall <NUM> of the pre-diffuser <NUM> and the inlet extender <NUM> proximate the distal end <NUM> may be less than <NUM> degrees. In an embodiment, the inlet extender <NUM> may also include a catcher <NUM> extending radially outward from the distal end <NUM>, as illustrated in <FIG>. The inlet extenders <NUM> shown in <FIG> each benefit from centrifugal filtering caused by centrifugal forces generated by the compressor section <NUM>, which forces particulate <NUM> radially outward and away from the inlet of the inlet extend <NUM> proximate the distal end <NUM>. In comparison, the inlet extenders <NUM> shown in <FIG> require a sharper turn than the inlet extender <NUM> shown in <FIG>, thus leading to relatively better filtration of particulate <NUM> by the inlet extender <NUM> shown in <FIG> but an associated pressure loss comes with the better filtration. The inlet extender <NUM> shown in <FIG> has a lower pressure loss experienced by the inlet extenders shown in <FIG> but relies on the centrifugal forces generated by the compressor section <NUM> for the majority of particulate <NUM> filtering and not sharp turns.

In another embodiment, the curvature of a forward portion <NUM> of the inlet extender <NUM> proximate the distal end <NUM> may follow a curvature of the forward dome <NUM>, such that the forward dome <NUM> and the inlet extender <NUM> are in a facing spaced relationship. Advantageously, by located the distal end <NUM> of the inlet extender <NUM> proximate the pre-diffuser <NUM>, the inlet orifice <NUM> of the TOBI module <NUM> is essentially moved forward or extended relative to the previous location in the aft end <NUM> of the inner shroud <NUM>. The distal end <NUM> of the inlet extender <NUM> is located in a high velocity region <NUM> of airflow <NUM> flow in the dump region <NUM>. Airflow <NUM> is at a higher velocity as the airflow <NUM> exits the pre-diffuser <NUM> and moves through the dump region <NUM> then the airflow proximate an aft end <NUM> of the inward shroud <NUM>.

The distal end <NUM> of the inlet extender <NUM> is configured to force the airflow <NUM> in the high velocity region <NUM> to make a hard turn at a distal end <NUM> of the inlet extender <NUM>. The airflow <NUM> is able to make the turn around the distal end <NUM> of the inlet extender <NUM>, however particulate <NUM> being carried along with the airflow <NUM> is typically not able to make this hard turn and centrifugal forces cause the particulate <NUM> to separate from the airflow <NUM>. Thus, the airflow <NUM> will continue into the first inner shroud 114a, while the particulate <NUM> moves through to the second inner shroud 114b.

Referring now to <FIG>, with continued reference to <FIG>, an inlet extender <NUM> that includes one or more orifices <NUM> is illustrated, in accordance with an embodiment of the present disclosure. The orifice <NUM> fluidly connects the first inner shroud 114a and the second inner shroud 114b. A ramp <NUM> is located in the first inner shroud 114a opposite the orifice <NUM>. The ramp <NUM> may extend away from the radially inward wall <NUM> of the diffuser case <NUM> toward the orifice <NUM> as illustrated in <FIG>. The ramp <NUM> may be oriented at an angle β1 that is less than <NUM> degrees relative to radially inward wall <NUM> as measured between the radially inward wall <NUM> and an aft side <NUM> of the ramp <NUM>. The ramp <NUM> extends to a distal end <NUM> proximate the orifice <NUM>.

The ramp <NUM> is oriented at the angle β1 to direct particulate <NUM> out of the first inner shroud 114a through the orifice <NUM> and into the second inner shroud 114b, thus preventing the particulate <NUM> from entering the TOBI module <NUM> and subsequently the turbine section <NUM>.

The distal end <NUM> of the ramp <NUM> is configured to force the airflow <NUM> to make a hard turn at the distal end <NUM> of the ramp <NUM>. The airflow <NUM> is able to make the turn around the distal end <NUM> of the ramp <NUM>, however particulate <NUM> being carried along with the airflow <NUM> are typically not able to make this hard turn and centrifugal forces cause the particulate <NUM> to separate from the airflow <NUM> at the distal end <NUM> of the ramp <NUM> where they are directed through the orifices. Thus, the airflow <NUM> will continue through the first inner shroud 114a, while the particulate <NUM> moves to the second inner shroud 114b. As illustrated in <FIG>, multiple ramp <NUM> and orifice <NUM> pairs may be arranged in series to provide multiple points for ejection of particulate <NUM>.

Technical effects of embodiments of the present disclosure include attaching an inlet extender onto an inlet of a TOBI module to extend the inlet to a high velocity zone of airflow within the diffuser case, where particulate centrifugal separation can occur prior to airflow entering the inlet extender.

Claim 1:
A diffuser case assembly for a gas turbine engine (<NUM>), comprising:
a pre-diffuser (<NUM>);
a diffuser case (<NUM>) defining a dump region (<NUM>), an inner plenum (<NUM>), and an outer plenum (<NUM>), the pre-diffuser (<NUM>) being fluidly connected to the inner plenum (<NUM>) and the outer plenum (<NUM>) through the dump region (<NUM>);
a tangential onboard injector module (<NUM>) fluidly connected to the inner plenum (<NUM>) through an inlet orifice (<NUM>) located in the diffuser case (<NUM>) proximate an aft end (<NUM>) of the inner plenum (<NUM>); and
an inlet extender (<NUM>) initiating at the inlet orifice (<NUM>) of the tangential onboard injector module (<NUM>), extends through the inner plenum (<NUM>), and terminates at a distal end (<NUM>) proximate the pre-diffuser (<NUM>), wherein:
the distal end (<NUM>) of the inlet extender (<NUM>) is located in the dump region (<NUM>);
the inlet extender (<NUM>) is interposed between the combustor (<NUM>) and a radially inward wall (<NUM>) of the diffuser case (<NUM>);
the distal end (<NUM>) of the inlet extender (<NUM>) is proximate to the pre-diffuser (<NUM>),
the combustor (<NUM>) comprises a forward dome (<NUM>);
the inlet extender (<NUM>) fluidly separates the inner plenum (<NUM>) into a first inner plenum (114a) and a second inner plenum (114b), wherein the inlet orifice (<NUM>) is fluidly connected to the first inner plenum (114a); and
the forward dome (<NUM>) and the inlet extender (<NUM>) are in a facing spaced relationship, characterized in that
the distal end is a free end.