Combined ball valve for compressor bleed air and methods

A combined ball valve for compressor bleed air modulation is provided. The combined ball valve includes a housing defining an inlet, and first and second outlets. A metering element is positioned within the housing and within a flow path extending from the inlet to the first and second outlets. The metering element includes first and second flow ports and is rotatable within the housing to modulate compressor bleed air from the inlet to neither, one, or both of the first and second outlets. The combined ball valve utilizes high temperature materials in a relatively lightweight package.

FIELD OF THE INVENTION

This invention generally relates to turbine engines, and more specifically to apparatus and methods for modulating bleed air from the compressor stages of a turbine engine.

BACKGROUND OF THE INVENTION

It is generally known in the art to syphon or “bleed” air from a compressor section of a turbine engine upstream from the combustion section. Such bleed air is used for a variety of functions including but not limited to cabin pressurization, engine operability, powering of pneumatic actuators, anti-icing, etc.

Contemporary systems modulate such bleed air through the use of multiple air valves. Each air valve is in fluid communication with a certain portion of the compressor section. Controlling the restriction offered by the internal metering element of each air valve controls the amount of bleed air that is allowed to flow from the compressor section. This modulated bleed air flows from each air valve to its appropriate destination to achieve one or more of the exemplary functions identified above.

Unfortunately, such contemporary systems are complex. Indeed, they typically involve multiple stand-alone air valves each having an independent actuator, or at least multiple separate flow bodies controlled by a single actuator, each being connected to the single actuator by way of a relatively complex linkage. As one example, a stage of compressor section may utilize two stand-alone air valves each having an actuator, or two separate flow bodies connected by way of a linkage to a single actuator. Each of the two air valves or flow bodies has its own respective inlet and outlet, and thus requires appropriate routing of conduit to and from each inlet and outlet to achieve its functionality.

While the above systems have proven to sufficiently modulate bleed air, they also have a large overall engine foot print, have a large part count, are generally complex in their linkages, and tend to be high cost. As such, there is a need in the art for an apparatus and method that modulates bleed air while presenting a reduction of parts yet a retention of function. Such a system would result in a smaller foot print, less complex, and less costly arrangement.

The invention provides such an apparatus and method. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.

BRIEF SUMMARY OF THE INVENTION

In one aspect, the invention provides an air valve for modulating bleed air from the compressor section of a turbine engine. The air valve includes a housing defining an inlet and first and second outlets, wherein a flow path extends through the housing and between the inlet and first and second outlets. A metering element is disposed within the housing and within the flow path. The metering element includes a first flow port and a second flow port. The metering element has a side wall with a curved outer periphery. The first and second flow ports extend through the side wall. The first port has a width which extends along the curved outer periphery at a first arc length. The second port has a width which extends along the curved outer periphery at a second arc length greater than the first arc length.

In another aspect, the invention provides an air valve for modulating bleed air from the compressor section of a turbine engine. The air valve includes a housing defining an inlet and first and second outlets. A flow path extends through the housing and between the inlet and first and second outlets. The first outlet has a first diameter, and the second outlet has a second diameter greater than the first diameter. A metering element is disposed within the housing and within the flow path. The metering element includes a first flow port and a second flow port. The metering element has a side wall. The first and second flow ports extend through the side wall. The first flow port has a first height. The second flow port has a second height greater than the first height.

The air valve may also include first and second shoes disposed on either side of the metering element. The first shoe is operable to communicate bleed air received from the first flow port to the first outlet. The second shoe is operable to communicate bleed air received from the second flow port to the second outlet. A first biasing element is interposed between a shoulder of the first shoe and an internal surface of the housing to bias the first shoe against the side wall of the metering element. A second biasing element is interposed between a shoulder of the second shoe and an internal surface of the housing to bias the second shoe against the sidewall of the metering element. The shoulders of each of the first and second shoes define a contact surface having an angle of about 20 degrees to about 70 degrees relative to an axis extending between the first and second outlets. The contact surface is in sealing contact with the side wall of the metering element.

In certain embodiments, at least one of the housing and metering element are formed from a high temperature material. In certain embodiments, the first and second shoes are formed from a high temperature material. The metering element may be rotationally supported within the housing by upper and lower bearings.

In yet another aspect, the invention provides an air valve assembly for modulating bleed air from a compressor section of a turbine engine. The air valve assembly includes an actuator and an air valve, the actuator mounted to the air valve. The air valve includes a housing having an inlet and first and second outlets, wherein a flow path extends between the inlet and first and second outlets. A metering element having a generally ellipsoid shape is disposed within the housing and within the flow path. The inlet is configured to receive bleed air from multiple distinct and independent sources from the compressor section. The actuator is operably connected to a valve stem of the metering element to rotate the metering element to modulate bleed air from the multiple distinct and independent sources of the compressor section between the first and second outlets.

The metering element includes a first flow port and a second flow port. The first and second flow ports have differing geometry. The first flow port is selectively alignable with the first outlet to fluidly communicate the first flow port with the first outlet and the second flow port is selectively alignable with the second outlet to fluidly communicate the second flow port with the second outlet.

The first and second flow ports are arranged such that the metering element is rotatable to a first position wherein a portion of the first flow port is in fluid communication with the first outlet and the second flow port is not in fluid communication with the second outlet. The metering element is rotatable to a second position wherein a portion of the first flow port is in fluid communication with the first outlet and the entirety of the second flow port is in fluid communication with the second outlet. The metering element is also rotatable to a third position wherein neither of the first and second flow ports are in fluid communication with the first and second outlets, respectively. The first flow port is generally semi-circular, and the second flow port is generally slotted in shape.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to the drawings,FIG. 1illustrates one embodiment of an air valve assembly20according to the teachings of the present invention. Air valve assembly20includes an air valve22coupled with an actuator24. As will be explained in greater detail below, air valve22advantageously provides a combined air valve which provides the functionality of the contemporary systems described above which utilize two separate air valves or flow bodies but does so in a single air valve package with a single actuator. Additionally, air valve22advantageously operates across a broad temperature range. As one example, air valve22may modulate air flow there through at a temperature ranging from about negative 100° F. to about 1200° F. While air valve22advantageously provides the functionality previously provided by two separate air valves, air valve22is advantageously driven by a single actuator24unlike prior designs. This actuator24is directly coupled to air valve22and thus the above described complex linkages are not required with the instant invention.

Actuator24may be any appropriate actuator designed for actuating a ball valve type apparatus. As non-limiting examples actuator24may be a linear, rotary, hydraulic, fueldraulic, or an electromagnetic type actuator. In the illustrated embodiment, those skilled in the art will recognize that actuator24is shown as a hydraulic or fueldraulic type actuator. Such illustration should be taken by way of example and not limitation.

Still referring toFIG. 1, air valve22includes an inlet26and first and second outlets28,30. The aforementioned inlet26and first and second outlets28,30are defined by a housing32which may be made from a high temperature material.

Inlet26is configured to receive bleed air from multiple stages of the compressor section of a turbine engine. As illustrated inFIG. 2, these stages are represented schematically ranging from stage1to stage N at44,26,48and are in effect multiple distinct and independent sources of bleed air. The first and second outlets28,30are operably connected to an exhaust path schematically represented as exhaust42. Exhaust42may be a single flow path to which each first and second outlets28,30are connected to, or in the alternative, may be separate flow paths with first and second outlets28,30respectively connected thereto. Compressor bleed air modulated through either or both of first and second outlets28,30may be used for a variety of functions as is known in the art, e.g. for de-icing operations, for maintaining optimal air pressure within the compressor section, etc. Those skilled in the art will also recognize that flow through air valve22may be reversed such that inlet26in effect functions as an outlet of air valve22, and first and second outlets28,30in effect function as inlets. Additionally, although second outlet30is illustrated as having a larger diameter than first outlet28, first and second outlets28,30may have a common diameter, or the diameter of first outlet28may be larger than the diameter of second outlet30in other embodiments.

Actuator24is also operably connected to actuator supply40. The particular characteristics of actuator supply40will vary depending on the type of actuator embodied by actuator24. As stated above, in the illustrated embodiment, actuator24is a hydraulic or fueldraulic actuator. As such, actuator supply40may be a hydraulic supply system for controlling actuator24and optionally other actuators. In the case of a fueldraulic actuator supply40may be part of a fuel supply system, particularly, the actuator supply portion thereof.

Turning now toFIG. 3, air valve22provides several actuator mounts54for mounting actuator24(seeFIG. 2) to air valve22. A valve stem56extends outwardly through housing32for connection to actuator24. Valve stem56is operably coupled to an internal metering element58of air valve22for modulating bleed air as described herein.

Turning now toFIG. 4, air valve22is illustrated in an exploded view to expose the internal componentry thereof. As can be seen in this view, the above described valve stem56and metering element58are shown. Shoes62,64are disposed on either side of metering element58and are biased there against by biasing elements66,68, respectively. Additionally, multi-part seals,70,72are disposed at the end of shoes62,64, respectively for preventing bleed air within air valve22from circumventing its required passage through shoes62,64to reach first and second outlets28,30, respectively. Biasing elements66,68respectively bias shoes62,64against the exterior of metering element58and provide a surface unit loading sufficient to sealingly bias a sealing surface of each of shoes62,64against metering element58. This unit loading may differ depending upon application, as those skilled in the art will recognize. Metering element58and shoes62,64may be made from high temperature materials. Additionally, these components may also incorporate high temperature coatings.

Shoes62,64ensure that bleed air routed through inlet26must first pass through metering element58before exiting out of one or both of first and second outlets28,30. Although shoes62,64are illustrated as biased against metering element58using biasing elements66,68, in an alternative embodiment, a bellows may also be utilized in place of each shoe62,64and its associated biasing element66,68. Such a configuration provides for the aforementioned routing capabilities of shoes62,64, while also providing the biasing force otherwise provided by biasing elements66,68.

Metering element58is supported for rotation about an axis passing through valve stem56by upper and lower bearings76,78. A washer and multi-part seal82are disposed above upper bearing76to prevent bleed air from leaking out of housing32due to the passage of valve stem56there through.

A support ring84supports lower bearing78and indirectly supports metering element58within housing32. A biasing element86in the form of a wave spring provides an upward biasing force against support ring84to firmly position metering element58within housing32. An upper portion of housing32also defines a sealing surface against which a cap92of housing seals. A seal94is positioned between cap92and the remainder of housing32.

Having introduced the components of air valve22, a description will now be provided for the particular features of metering element58relative toFIGS. 5-8. With particular reference toFIG. 5, metering element58includes a first flow port102and a second flow port104. As will be described in greater detail below, first and second flow ports102,104have differing geometry to achieve the compressor bleed air functionality described herein, although the particular geometry illustrated should be taken by way of example only. Indeed, other port geometries are contemplated. These first and second flow ports102,104are formed through a side wall108of metering element58. Additionally, a plurality of apertures106are formed through a top wall110of metering element58. As can be seen from inspection ofFIG. 5, metering element58is generally ellipsoid in shape with the exception that it has a flat top and a flanged configuration at the bottom thereof. In other embodiments, metering element may be spherical or any other shape depending upon application.

With reference now toFIG. 6, an opening112is formed through a bottom wall114of metering element58. This opening112communicates with inlet26(SeeFIG. 2) of air valve22. Bleed air is allowed to flow in through opening112, and depending upon the rotational position of metering element58, out of either, both, or none of first and second outlets28,30.

Turning now toFIGS. 7 and 8, several geometrical descriptions will be provided for first and second flow ports102,104. With particular reference toFIG. 7, a cross section of metering element58is illustrated taking it through a plane P within which the geometrical centroids of first and second flow ports102,104are disposed. An ellipse E is disposed within plane P and assumes the outer periphery of metering element58. As can be seen in this view, the arc length S1of first flow port102is greater than the arc length S2of second flow port104. With reference toFIG. 8, the overall height H1of second flow port104is greater than the overall height a of first flow port102. This difference in port geometry allows for the modulation of bleed air to either, none, or both of first and second outlets28,30as described below.

Turning now toFIG. 9, a side cross section taken through air valve22is illustrated therein. As can be seen in this view, shoes62,64respectively define shoulders116,118which present an angled contact surface which as described above is biased against side wall108of metering element58. The particular angle of the surface of shoulders116,118which contacts side wall108is selected to ensure a desired sealing against metering element28as well as the above unit loading there against. This angle may range from about 20 degrees to about 70 degrees as one example. As can also be seen in the cross section ofFIG. 9, the flange portion of metering element58defines a shoulder120which seats against a top surface of lower bearing78to aid in locating metering element58within housing32.

Turning now toFIGS. 10-12, a description will be provided for the modulation capabilities of air valve22. With particular reference toFIG. 10, the same illustrates a top cross section of air valve22. As can be seen in this view, each of first and second flow ports102,104are positioned such that flow of compressor bleed air from inlet26to first and second outlets28,30is prevented. However, and with reference now toFIG. 11, rotation of metering element58in rotational direction122as illustrated will expose first flow port102to first outlet28as illustrated. However, second flow port104is not exposed to second outlet30. As a result, incoming bleed air through inlet26is modulated exclusively through air valve22out of first outlet28.

With reference now toFIG. 12, continued rotation in direction122will continue to expose first flow port102to first outlet28. However, second flow port104is now additionally exposed to second outlet30as shown. As a result, compressor bleed air entering air vale22through inlet26is modulated through both the first and second outlets28,30. It should be immediately recognized that the particular shape of first and second flow ports102,104thus allows for the modulation of bleed air through one, both, or neither of first and second outlets28,30. This advantageously allows for the regulation of bleed air two multiple exhaust paths (see exhaust42FIG. 1) using a single metering element of a single air valve controlled by a single actuator, unlike prior designs which require multiple flow bodies and in some cases multiple actuators.

As described above, various high temperature materials are utilized in air valve22to allow it to operate with high temperature compressor bleed air passing there through. Additionally, air valve22utilizes a generally thin wall thickness relative to its housing and flow to reduce weight. As such, air valve assembly20not only provides the functionality of systems which heretofore utilized two separate air valves, the same also does so without losing its ability to function in combined high temperature and high pressure environments.